544 results on '"Cell Nucleus metabolism"'
Search Results
2. Studies Conducted at Moscow MV Lomonosov State University on Molecular Biology Recently Reported (Guanine Quadruplexes In Cell Nucleus Metabolism)
- Subjects
Nucleic acids -- Physiological aspects -- Research ,Guanine -- Research ,Molecular biology -- Physiological aspects -- Research ,Physical fitness -- Research -- Physiological aspects ,Health - Abstract
2021 NOV 27 (NewsRx) -- By a News Reporter-Staff News Editor at Obesity, Fitness & Wellness Week -- Current study results on Biology - Molecular Biology have been published. According [...]
- Published
- 2021
3. Guanine Quadruplexes in Cell Nucleus Metabolism
- Author
-
Vasily M. Studitsky and E. V. Marilovtseva
- Subjects
Regulation of gene expression ,Chemistry ,Biophysics ,RNA ,Ribosome ,Cell biology ,Nucleic acid secondary structure ,chemistry.chemical_compound ,Telomere Homeostasis ,Structural Biology ,Nucleic acid ,heterocyclic compounds ,Nuclear protein ,DNA - Abstract
Cell metabolism depends, to a large extent, on correct regulation of gene expression. One of the mechanisms of regulation is the formation of nucleic acid secondary structures, among which guanine quadruplexes (G-quadruplexes, or G4) are of particular importance. G-quadruplexes are dynamic structures whose stability is determined by their size, ionic composition, and the nature of the nucleic acids forming them. They are regulated by various protein factors. Guanine quadruplexes play an important role in the regulation of many processes occurring in DNA and RNA, from maintaining telomere homeostasis to determining the ribosome landing site on mRNA. Therefore, these structures are considered a promising target for antitumor therapy, and their detailed study is important to modern biology. This review is focused on the structure and thermodynamic properties of G-quadruplexes together with their interaction with some nuclear proteins.
- Published
- 2021
4. [Guanine Quadruplexes in Cell Nucleus Metabolism]
- Author
-
E V, Marilovtseva and V M, Studitsky
- Subjects
G-Quadruplexes ,RNA ,Thermodynamics ,DNA ,Telomere - Abstract
Cell metabolism depends, to a large extent, on correct regulation of gene expression. One of the mechanisms of regulation is the formation of nucleic acid secondary structures, among which guanine quadruplexes (G-quadruplexes, or G4) are of particular importance. G-quadruplexes are dynamic structures whose stability is determined by their size, ionic composition, and the nature of the nucleic acids forming them. They are regulated by various protein factors. Guanine quadruplexes play an important role in the regulation of many processes occurring in DNA and RNA, from maintaining telomere homeostasis to determining the ribosome landing site on mRNA. Therefore, these structures are considered a promising target for antitumor therapy, and their detailed study is important to modern biology. This review is focused on the structure and thermodynamic properties of G-quadruplexes together with their interaction with some nuclear proteins.
- Published
- 2021
5. INTERNATIONAL SYMPOSIUM ON THE CELL NUCLEUS: METABOLISM AND RADIOSENSITIVITY, RIJSWIJK Z.H., NETHERLANDS, 9 - 12 MAY 1966
- Abstract
This symposium was a closed meeting organized by the Radiobiological Institute of the Netherlands Organization for Applied Scientific Research (TNO). It was held in Rijswijk, Holland, from 9 -12 May 1966. Attendance was limited to 46 invited participants representing 9 countries. The discussions held during this symposium have been summarized in reference to a simplified schematic outline of the molecular circuits of the cell. In preparing these summaries major emphasis was placed on reporting original work pertaining to circuit function and its disturbances caused by ionizing radiation and chemical agents known to produce some effects similar to radiation. Reviews and analytical papers pertaining to the description of the components of the circuits have been mentioned briefly. (Author)
- Published
- 1966
6. Impaired angiogenesis in aging myocardial microvascular endothelial cells is associated with reduced importin alpha and decreased nuclear transport of HIF1 alpha: mechanistic implications.
- Author
-
Ahluwalia, A, Narula, J, Jones, M K, Deng, X, and Tarnawski, A S
- Subjects
Age Factors ,Aging ,Animals ,Cell Nucleus: metabolism ,Cytoplasm: metabolism ,Down-Regulation ,Endothelium ,Vascular: metabolism ,Hypoxia-Inducible Factor 1 ,alpha Subunit: genetics ,metabolism ,Microvessels: metabolism ,Myocardium: metabolism ,Neovascularization ,Physiologic ,Protein Binding ,Protein Transport ,Rats ,Rats ,Inbred F344 ,Vascular Endothelial Growth Factor A: genetics ,metabolism ,alpha Karyopherins: genetics ,metabolism ,aging ,angiogenesis ,myocardial microvascular endothelial cells ,importin alpha ,hypoxia-inducible factor 1 alpha ,vascular endothelial growth factorgrowth-factor ,hypoxia ,hif-1-alpha ,expression ,infarction ,ischemia ,hearts ,model ,gene ,Age Factors ,Aging ,Animals ,Cell Nucleus: metabolism ,Cytoplasm: metabolism ,Down-Regulation ,Endothelium ,Vascular: metabolism ,Hypoxia-Inducible Factor 1 ,alpha Subunit: genetics ,metabolism ,Microvessels: metabolism ,Myocardium: metabolism ,Neovascularization ,Physiologic ,Protein Binding ,Protein Transport ,Rats ,Rats ,Inbred F344 ,Vascular Endothelial Growth Factor A: genetics ,metabolism ,alpha Karyopherins: genetics ,metabolism ,aging ,angiogenesis ,myocardial microvascular endothelial cells ,importin alpha ,hypoxia-inducible factor 1 alpha ,vascular endothelial growth factorgrowth-factor ,hypoxia ,hif-1-alpha ,expression ,infarction ,ischemia ,hearts ,model ,gene - Abstract
Aging is associated with increased incidence of myocardial infarctions and impaired angiogenesis - new capillary blood vessel formation from preexisting vessels. The molecular mechanism(s) of aging-related impairment of angiogenesis are unknown. In the present study we focused on the mechanism of activation of the gene for vascular endothelial growth factor (VEGF - the most potent stimulator of angiogenesis) in young and aging myocardial microvascular endothelial cells (MMEC). Activation of VEGF gene in the cell nucleus is mediated in part by the transcription factor hypoxia-inducible factor 1 alpha (HIF1 alpha). In order to activate VEGF gene, HIF1 alpha must first be transported to the nucleus, but the mechanisms of this transport are unknown. We hypothesized that reduced VEGF gene activation and impaired angiogenesis in myocardium during aging can result from downregulation of the nuclear transport receptor - importin alpha that leads to decreased transport of HIF1 alpha to the nucleus. We examined in MMEC isolated from young (3 months of age) and aging (24 months old) Fisher F-344 rats: 1) in vitro angiogenesis; and 2) the expression of VEGF, importin alpha and HIF1 alpha. Aging MMEC exhibited a 3.7-fold reduction in angiogenesis and a corresponding reduction in VEGF (by 3-fold) and importin alpha (by 1.9-fold) levels compared to young MMEC. Aging MMEC also exhibited cytoplasmic accumulation (by 1.8-fold) of HIF1 alpha protein, reduced HIF1 alpha transport to the nucleus and decreased binding of HIF1 alpha protein to the VEGF gene promoter. This study is the first demonstration of the downregulation of importin alpha in aging MMEC and reduced nuclear transport of HIF1 alpha, which likely lead to decreased VEGF gene activation and impaired angiogenesis.
- Published
- 2010
7. Developmental expression of CREB1 and NFATC2 in pig embryos
- Author
-
Knud Larsen and Henrik Callesen
- Subjects
RNA, Messenger/genetics ,Pig ,Swine/genetics ,Brain ,Embryonic Development ,Expression ,NFATC2 ,General Medicine ,Cyclic AMP Response Element-Binding Protein/genetics ,Gene Expression Regulation ,Embryo ,Cell Nucleus/metabolism ,Genetics ,CREB1 ,Animals ,Molecular Biology - Abstract
Background: The CREB1 gene encodes the cAMP response element binding protein 1 (CREB1), a leucine zipper transcription factor that regulates cellular gene expression in response to elevated levels of intracellular cAMP. When activated by phosphorylation, CREB1 binds to the cAMP response element (CRE) of the promoters of its target genes. CREB1 is an essential component in many physiological processes, and its function is correlated to neurodevelopment, plasticity and cell survival, and learning and memory. The NFATC2 gene codes for the nuclear factor of activated T-cells 2 protein. The NFATC2 protein is a DNA-binding protein that functions as an inducer of gene transcription during immune response. Methods and results: The aim of the present study was to examine the developmental expression of porcine CREB1 and NFACT2 transcripts. The expression of CREB1 and NFACT2 mRNA was examined by quantitative real-time RT-PCR. For the CREB1 transcript, we found significant reduction in transcript levels in the brain stem and basal ganglia during porcine embryo development, determined from day 60 to day 115 of gestation. In contrast, a significant increase in CREB1 mRNA was detected in the lungs during embryo development. No significant changes in the NFATC2 transcript were detected in porcine brain tissue during embryo development. Conclusions: Differential CREB1 mRNA expression was found in pig brain tissues during embryo development.
- Published
- 2023
8. Comparative expression of NFkappaB proteins in melanocytes of normal skin vs. benign intradermal naevus and human metastatic melanoma biopsies.
- Author
-
McNulty, Susan E, del Rosario, Raul, Cen, Dazhi, Meyskens, Frank L, Jr, and Yang, Sun
- Subjects
Apoptosis ,Biopsy ,Cell Nucleus: metabolism ,Cytoplasm: metabolism ,Humans ,I-kappa B Proteins: metabolism ,Immunohistochemistry ,Melanocytes: metabolism ,Melanoma: metabolism ,NF-kappa B: metabolism ,Nevus: metabolism ,Nevus ,Intradermal: metabolism ,Phosphoserine: metabolism ,Signal Transduction ,Skin: metabolism ,Transcription Factor RelA ,cRel ,Inhibitor of kappa B-α ,Inhibitor of kappa B-β ,Inhibitor of kappa B-ε ,Nuclear factor kappa B ,RelAI kappa B ,immunoglobulin enhancer binding protein ,transcription factor Rel ,I kappa B ,immunoglobulin enhancer binding protein ,NF kappaB inhibitor alpha ,NF-kappaB inhibitor alpha ,phosphoserine ,transcription factor RelA ,apoptosis ,article ,controlled study ,gene expression ,human ,human tissue ,immunohistochemistry ,immunoperoxidase staining ,melanocyte ,melanoma ,nevus ,nuclear localization signal ,protein phosphorylation ,skin biopsy ,transactivation ,biopsy ,cell nucleus ,cytoplasm ,metabolism ,signal transduction ,skin ,Apoptosis ,Biopsy ,Cell Nucleus ,Cytoplasm ,Humans ,I-kappa B Proteins ,Immunohistochemistry ,Melanocytes ,Melanoma ,Nevus ,Nevus ,Intradermal ,NF-kappa B ,Phosphoserine ,Signal Transduction ,Skin ,Transcription Factor RelA - Abstract
Nuclear factor kappa B (NFkappaB) is an essential regulator of gene transcription for hundreds of genes, including many critically involved in apoptosis. NFkappaB complexes containing cRel generally activate pro-apoptotic genes, while those with RelA activate anti-apoptotic genes. We have previously shown that NFkappaB binding by RelA is constitutively elevated in human metastatic melanoma cultures relative to normal melanocytes. Here we extended our investigation to immunohistochemical analysis of human tissue biopsies. We found that RelA expression is significantly elevated in melanocytes of human naevi and melanomas relative to normal skin, but expression of its inhibitor IkappaB-alpha is significantly lower in metastatic melanomas than in intradermal naevi. Antibodies specific for the nuclear localization signal of RelA also showed significantly increased staining in metastatic melanoma biopsies. Notably, in melanomas and in naevi, we also found that RelA is phosphorylated at serine 529, and this activated form accumulates in the nuclei of melanomas. This suggests that increased expression and phosphorylation of RelA occurs at the stage of the benign naevus, but IkappaB-alpha is able to sequester RelA in the cytoplasm and regulate RelA transcriptional transactivation. We also found that antibodies against cRel show a progressive increase in staining from naevi to melanoma. However, staining for IkappaB-epsilon, which primarily inhibits the nuclear localization of cRel was also progressively increased, and cRel expression was predominantly cytoplasmic in melanomas. These results confirm that the altered expression of RelA found in metastatic melanoma cells in tissue culture is relevant to human tumors and offer new insights into the deregulation of NFkappaB signaling.
- Published
- 2004
9. Cellular origin of ionizing radiation-induced NF-kappaB activation in vivo and role of NF-kappaB in ionizing radiation-induced lymphocyte apoptosis.
- Author
-
Meng, A, Yu, T, Chen, G, Brown, S A, Wang, Y, Thompson, J S, and Zhou, D
- Subjects
Animals ,Annexin A5: pharmacology ,Apoptosis ,B-Lymphocytes: radiation effects ,Carbocyanines: pharmacology ,Cell Nucleus: metabolism ,Dose-Response Relationship ,Drug ,Dose-Response Relationship ,Radiation ,Fluorescent Dyes: pharmacology ,G1 Phase: radiation effects ,Genes ,RAG-1: genetics ,In Situ Nick-End Labeling ,Lymphocytes: pathology ,Male ,Mice ,Mice ,Inbred BALB C ,Mice ,Knockout ,NF-kappa B: metabolism ,physiology ,Oligonucleotides: pharmacology ,Radiation ,Ionizing ,Resting Phase ,Cell Cycle: radiation effects ,Spleen: cytology ,T-Lymphocytes: radiation effects ,Time Factors - Abstract
To investigate the cellular origin of ionizing radiation (IR)-induced NF-kappaB activation in vivo and the role of NF-kappaB in IR-induced lymphocyte apoptosis.NF-kappaB activities were analysed by gel shift/supershift assay in isolated murine T- and B-cells, macrophages (MPhi) and tissues from normal and T- and B-cell-deficient Rag1 mice with or without exposure to IR. IR-induced lymphocyte apoptosis was determined by analysis of 3,3'-dihexyloxacarbocyanine iodide (DiOC(6)) uptake, annexin-V staining and the sub-G0/1 population, or by TUNEL assay.The results showed that IR activated NF-kappaB in lymphocytes, including both T- and B-cells, but failed to do so in MPhi. Furthermore, T- and B-cell-deficient Rag1 mice exposed to IR exhibited a significant reduction in NF-kappaB activation as compared with normal mice. Although NF-kappaB1 (p50) gene knockout or NF-kappaB decoy oligonucleotide treatment specifically inhibited IR-induced lymphocyte NF-kappaB activation, they had no significant effect on IR-induced lymphocyte apoptosis.This finding suggests that lymphocytes are the main cellular origin of IR-induced NF-kappaB activation in vivo. However, NF-kappaB activation has no significant effect on IR-induced lymphocyte apoptosis.
- Published
- 2003
10. Effects of NF-kappaB1 (p50) targeted gene disruption on ionizing radiation-induced NF-kappaB activation and TNFalpha, IL-1alpha, IL-1beta and IL-6 mRNA expression in vivo.
- Author
-
Zhou, D, Yu, T, Chen, G, Brown, S A, Yu, Z, Mattson, M P, and Thompson, J S
- Subjects
Animals ,Bone Marrow: radiation effects ,Cell Nucleus: metabolism ,Enzyme Activation: radiation effects ,Interleukin-1: metabolism ,Interleukin-6: metabolism ,Lymph Nodes: radiation effects ,Male ,Mice ,Mice ,Inbred BALB C ,Mice ,Knockout ,Mutagenesis ,Site-Directed ,NF-kappa B: genetics ,NF-kappa B p50 Subunit ,RNA ,Messenger: metabolism ,Radiation ,Ionizing ,Ribonucleases: metabolism ,Spleen: radiation effects ,Time Factors ,Tissue Distribution ,Transcription ,Genetic ,Tumor Necrosis Factor-alpha: metabolism - Abstract
To investigate the role of the NF-kappaB1 (p50) gene in ionizing radiation (IR)-induced NF-kappaB activation and TNFalpha, IL-1alpha, IL-1beta and IL-6 mRNA expression in vivo.NF-kappaB activation was analysed by the gel shift/supershift assay and the levels of TNFalpha, IL-1alpha, IL-1beta and IL-6 mRNA were measured using RNase protection assay (RPA). Various tissues from BALB/c, B6,129P-Nfkb1 (NF-kappaB1 or p50 gene knockout, p50(-/-)) and B6,129PF2 (wild-type, p50(+/+)) mice were analysed before or after exposure to a lethal dose (8.5 Gy) of total-body gamma-irradiation.Exposure of BALB/c mice to total-body IR selectively activated NF-kappaB in the spleen, mesenteric lymph nodes (LN) and bone marrow (BM). Gel supershift assay using polyclonal antibodies against NF-kappaB p50, p65 or c-Rel protein revealed that the NF-kappaB p50 subunit is a critical component of the NF-kappaB complexes activated by IR in vivo. Discretely augmented TNFalpha, IL-1alpha, IL-1beta and IL-6 mRNA expression was found in the spleen, LN and BM after BALB/c mice received IR. However, mice lacking the p50 gene (p50(-/-)) showed a significant reduction in IR-induced activation of NF-kappaB and increases in TNFalpha, IL-1alpha, IL-1beta and IL-6 mRNA expression, as compared with that of wild-type mice (p50(+/+)).The NF-kappaB p50 subunit is a critical component of the NF-kappaB complexes activated by IR and it plays an important role in mediating IR-induced TNFalpha, IL-1alpha, IL-1beta and IL-6 mRNA expression in vivo.
- Published
- 2001
11. Subnuclear gene positioning through lamina association affects copper tolerance
- Author
-
Sakamoto, Y., Sato, M., Sato, Y., Harada, A., Suzuki, T., Goto, C., Tamura, K., Toyooka, K., Kimura, Hiroshi, Ohkawa, Y., Hara-Nishimura, I., Takagi, S., and Matsunaga, S.
- Subjects
0106 biological sciences ,0301 basic medicine ,Lamina ,genetic structures ,Arabidopsis ,General Physics and Astronomy ,01 natural sciences ,Gene Expression Regulation, Plant ,Gene expression ,RNA-Seq ,lcsh:Science ,In Situ Hybridization, Fluorescence ,Plant Proteins ,Regulation of gene expression ,Multidisciplinary ,Arabidopsis Proteins/genetics/metabolism ,biology ,Nuclear Proteins ,Copper/*metabolism ,Nuclear Proteins/genetics/metabolism ,Chromatin ,Cell biology ,Nuclear lamina ,Mutation/genetics ,Science ,Locus (genetics) ,Article ,General Biochemistry, Genetics and Molecular Biology ,Chromatin/metabolism ,03 medical and health sciences ,Developmental biology ,Arabidopsis/genetics ,Gene ,Nuclear Lamina/genetics/metabolism/ultrastructure ,Cell Nucleus ,Nuclear Lamina ,Arabidopsis Proteins ,General Chemistry ,biology.organism_classification ,030104 developmental biology ,Cell Nucleus/metabolism ,Mutation ,lcsh:Q ,Plant Proteins/genetics/metabolism ,Plant sciences ,Copper ,010606 plant biology & botany - Abstract
The nuclear lamina plays an important role in the regulation of chromatin organization and gene positioning in animals. CROWDED NUCLEI (CRWN) is a strong candidate for the plant nuclear lamina protein in Arabidopsis thaliana but its biological function was largely unknown. Here, we show that CRWNs localize at the nuclear lamina and build the meshwork structure. Fluorescence in situ hybridization and RNA-seq analyses revealed that CRWNs regulate chromatin distribution and gene expression. More than 2000 differentially expressed genes were identified in the crwn1crwn4 double mutant. Copper-associated (CA) genes that form a gene cluster on chromosome 5 were among the downregulated genes in the double mutant exhibiting low tolerance to excess copper. Our analyses showed this low tolerance to copper was associated with the suppression of CA gene expression and that CRWN1 interacts with the CA gene locus, enabling the locus to localize at the nuclear lamina under excess copper conditions., The nuclear lamina regulates chromatin organization and gene positioning. Here the authors show that CROWDED NUCLEI proteins contribute to the meshwork lamina structure in Arabidopsis nuclei and regulate copper tolerance by promoting lamina association and expression of copper response genes.
- Published
- 2020
12. Constitutive activation of canonical Wnt signaling disrupts choroid plexus epithelial fate
- Author
-
Arpan Parichha, Varun Suresh, Mallika Chatterjee, Aditya Kshirsagar, Lihi Ben-Reuven, Tsviya Olender, M. Mark Taketo, Velena Radosevic, Mihaela Bobic-Rasonja, Sara Trnski, Michael J. Holtzman, Nataša Jovanov-Milosevic, Orly Reiner, and Shubha Tole
- Subjects
Telencephalon ,Male ,beta Catenin / genetics ,Science ,Telencephalon / metabolism ,General Physics and Astronomy ,Epithelium ,General Biochemistry, Genetics and Molecular Biology ,Epithelium / metabolism ,Mice ,Wnt Signaling Pathway / genetics ,beta Catenin / metabolism ,Animals ,Humans ,Choroid Plexus / pathology ,Wnt Signaling Pathway ,beta Catenin ,Cell Nucleus ,Multidisciplinary ,Cell Nucleus / metabolism ,Cell Differentiation ,Wnt Signaling Pathway / physiology ,General Chemistry ,eye diseases ,Wnt Proteins ,telencephalic ventricles ,beta-catenin ,cerebrospinal fluid ,neuronal identity ,hESC organoid ,Wnt Proteins / metabolism ,Choroid Plexus ,Female ,sense organs ,Choroid Plexus / metabolism - Abstract
The choroid plexus secretes cerebrospinal fluid and is critical for the development and function of the brain. In the telencephalon, the choroid plexus epithelium arises from the Wnt- expressing cortical hem. Canonical Wnt signaling pathway molecules such as nuclear β-CATENIN are expressed in the mouse and human embryonic choroid plexus epithelium indicating that this pathway is active. Point mutations in human β-CATENIN are known to result in the constitutive activation of canonical Wnt signaling. In a mouse model that recapitulates this perturbation, we report a loss of choroid plexus epithelial identity and an apparent transformation of this tissue to a neuronal identity. Aspects of this phenomenon are recapitulated in human embryonic stem cell derived organoids. The choroid plexus is also disrupted when β-Catenin is conditionally inactivated. Together, our results indicate that canonical Wnt signaling is required in a precise and regulated manner for normal choroid plexus development in the mammalian brain.
- Published
- 2022
13. The Cell Nucleus–Metabolism and Radiosensitivity
- Author
-
Howard, Alma, primary
- Published
- 1966
- Full Text
- View/download PDF
14. ReviewsThe Cell Nucleus—Metabolism and Radiosensitivity. Proceedings of a Symposium May 9–12, 1966, pp. 349 (illus.), 1966 (London, Taylor & Francis), Cloth bound—£4 10s. Paper bound—£3 15s.
- Author
-
Lajtha, L. G., primary
- Published
- 1967
- Full Text
- View/download PDF
15. Live imaging of adult zebrafish cardiomyocyte proliferation ex vivo
- Author
-
Katharina F Sonnen, Phong D. Nguyen, Jeroen Bakkers, Veronique E M van der Velden, Hessel Honkoop, and Hubrecht Institute for Developmental Biology and Stem Cell Research
- Subjects
Male ,Research Report ,Zebrafish Proteins/metabolism ,Proliferation ,Sarcomere ,Animals, Genetically Modified ,Sarcomeres/metabolism ,Myocytes, Cardiac ,Cardiomyocyte proliferation ,Zebrafish ,Cells, Cultured ,Mammals ,Cultured ,biology ,Mammals/metabolism ,Calpain ,Calpain/metabolism ,Cytokinesis/physiology ,Heart ,Myocytes, Cardiac/metabolism ,Cell biology ,Heart/physiology ,Cardiac/metabolism ,Female ,Cardiac ,Regeneration/physiology ,Sarcomeres ,Proteasome Endopeptidase Complex ,Cardiovascular Development and Regeneration ,Cells ,Cell Proliferation/physiology ,Live cell imaging ,Zebrafish/metabolism ,Animals ,Regeneration ,Molecular Biology ,Genetically Modified/metabolism ,Cell Proliferation ,Cytokinesis ,Cell Nucleus ,Myocytes ,Live-imaging ,Regeneration (biology) ,Animals, Genetically Modified/metabolism ,Zebrafish Proteins ,biology.organism_classification ,Proteasome Endopeptidase Complex/metabolism ,Cell Nucleus/metabolism ,biology.protein ,Ex vivo ,Developmental Biology - Abstract
Zebrafish are excellent at regenerating their heart by reinitiating proliferation in pre-existing cardiomyocytes. Studying how zebrafish achieve this holds great potential in developing new strategies to boost mammalian heart regeneration. Nevertheless, the lack of appropriate live-imaging tools for the adult zebrafish heart has limited detailed studies into the dynamics underlying cardiomyocyte proliferation. Here, we address this by developing a system in which cardiac slices of the injured zebrafish heart are cultured ex vivo for several days while retaining key regenerative characteristics, including cardiomyocyte proliferation. In addition, we show that the cardiac slice culture system is compatible with live timelapse imaging and allows manipulation of regenerating cardiomyocytes with drugs that normally would have toxic effects that prevent their use. Finally, we use the cardiac slices to demonstrate that adult cardiomyocytes with fully assembled sarcomeres can partially disassemble their sarcomeres in a calpain- and proteasome-dependent manner to progress through nuclear division and cytokinesis. In conclusion, we have developed a cardiac slice culture system, which allows imaging of native cardiomyocyte dynamics in real time to discover cellular mechanisms during heart regeneration., Summary: A method that allows live imaging of proliferating cardiomyocytes during zebrafish heart regeneration in their native tissue context.
- Published
- 2021
16. Nuclear Ubiquitin-Proteasome Pathways in Proteostasis Maintenance
- Author
-
Klara Zubčić, Dina Franić, and Mirta Boban
- Subjects
Proteasome Endopeptidase Complex ,Protein Folding ,Proteasome Endopeptidase Complex / metabolism ,lcsh:QR1-502 ,Review ,Protein degradation ,yeast ,Biochemistry ,inner nuclear membrane ,lcsh:Microbiology ,03 medical and health sciences ,0302 clinical medicine ,Protein structure ,Ubiquitin ,ubiquitin ,Inner membrane ,Animals ,Humans ,Proteostasis ,protein quality control ,protein misfolding ,Molecular Biology ,030304 developmental biology ,Cell Nucleus ,0303 health sciences ,proteostasis ,biology ,Chemistry ,Endoplasmic reticulum ,nucleus ,Ubiquitin / metabolism ,proteasome ,Cell biology ,Proteasome ,Cytoplasm ,Proteolysis ,Cell Nucleus / metabolism ,biology.protein ,030217 neurology & neurosurgery - Abstract
Protein homeostasis, or proteostasis, is crucial for the functioning of a cell, as proteins that are mislocalized, present in excessive amounts, or aberrant due to misfolding or other type of damage can be harmful. Proteostasis includes attaining the correct protein structure, localization, and the formation of higher order complexes, and well as the appropriate protein concentrations. Consequences of proteostasis imbalance are evident in a range of neurodegenerative diseases characterized by protein misfolding and aggregation, such as Alzheimer’s, Parkinson’s, and amyotrophic lateral sclerosis. To protect the cell from the accumulation of aberrant proteins, a network of protein quality control (PQC) pathways identifies the substrates and direct them towards refolding or elimination via regulated protein degradation. The main pathway for degradation of misfolded proteins is the ubiquitin-proteasome system. PQC pathways have been first described in the cytoplasm and the endoplasmic reticulum, however, accumulating evidence indicates that the nucleus is an important PQC compartment for ubiquitination and proteasomal degradation of not only nuclear, but also cytoplasmic proteins. In this review, we summarize the nuclear ubiquitin-proteasome pathways involved in proteostasis maintenance in yeast, focusing on inner nuclear membrane-associated degradation (INMAD) and San1-mediated protein quality control.
- Published
- 2021
17. Palmdelphin Regulates Nuclear Resilience to Mechanical Stress in the Endothelium
- Author
-
Oscar Plunde, Ross O Smith, Qingsen Li, Marco Foiani, Cansaran Saygili Demir, Anders Franco-Cereceda, Marie Hedlund, Sofia Nordling, Lena Claesson-Welsh, Flora Ascione, Miguel Sáinz-Jaspeado, Yindi Ding, Manfred W. Kilimann, Sven-Christian Pawelzik, Pontus Aspenström, Jeffrey Kroon, Giulia Bastianello, Magnus Bäck, Yi Jin, Tatiana V. Petrova, Dinesh Fernando, Geoffrey Daniel, Experimental Vascular Medicine, ACS - Atherosclerosis & ischemic syndromes, ACS - Microcirculation, and AGEM - Amsterdam Gastroenterology Endocrinology Metabolism
- Subjects
Male ,Gene Expression ,aortic valve stenosis ,Cell Communication ,Mice ,Cell Movement ,Original Research Articles ,Databases, Genetic ,Medicine ,Aged ,Animals ,Cell Communication/genetics ,Cell Line ,Cell Movement/genetics ,Cell Nucleus/genetics ,Cell Nucleus/metabolism ,Cells, Cultured ,Computational Biology/methods ,Endothelial Cells/metabolism ,Endothelium/metabolism ,Female ,Gene Expression Profiling ,Gene Knockdown Techniques ,Gene Ontology ,Humans ,Immunohistochemistry ,Membrane Proteins/genetics ,Membrane Proteins/metabolism ,Mice, Knockout ,Middle Aged ,Protein Transport ,Stress, Mechanical ,endothelial cells ,nucleocytoplasmic transport ,palmdelphin ,Cardiac and Cardiovascular Systems ,Cytoskeleton ,Kardiologi ,Cell biology ,medicine.anatomical_structure ,ComputingMethodologies_DOCUMENTANDTEXTPROCESSING ,Palmdelphin ,Cardiology and Cardiovascular Medicine ,Endothelium ,Locus (genetics) ,Single-nucleotide polymorphism ,Paralemmin ,Physiology (medical) ,Resilience (network) ,Cell Nucleus ,business.industry ,Computational Biology ,Membrane Proteins ,Immunology in the medical area ,Nucleocytoplasmic Transport ,business - Abstract
Supplemental Digital Content is available in the text., Background: PALMD (palmdelphin) belongs to the family of paralemmin proteins implicated in cytoskeletal regulation. Single nucleotide polymorphisms in the PALMD locus that result in reduced expression are strong risk factors for development of calcific aortic valve stenosis and predict severity of the disease. Methods: Immunodetection and public database screening showed dominant expression of PALMD in endothelial cells (ECs) in brain and cardiovascular tissues including aortic valves. Mass spectrometry, coimmunoprecipitation, and immunofluorescent staining allowed identification of PALMD partners. The consequence of loss of PALMD expression was assessed in small interferring RNA-treated EC cultures, knockout mice, and human valve samples. RNA sequencing of ECs and transcript arrays on valve samples from an aortic valve study cohort including patients with the single nucleotide polymorphism rs7543130 informed about gene regulatory changes. Results: ECs express the cytosolic PALMD-KKVI splice variant, which associated with RANGAP1 (RAN GTP hydrolyase activating protein 1). RANGAP1 regulates the activity of the GTPase RAN and thereby nucleocytoplasmic shuttling via XPO1 (Exportin1). Reduced PALMD expression resulted in subcellular relocalization of RANGAP1 and XPO1, and nuclear arrest of the XPO1 cargoes p53 and p21. This indicates an important role for PALMD in nucleocytoplasmic transport and consequently in gene regulation because of the effect on localization of transcriptional regulators. Changes in EC responsiveness on loss of PALMD expression included failure to form a perinuclear actin cap when exposed to flow, indicating lack of protection against mechanical stress. Loss of the actin cap correlated with misalignment of the nuclear long axis relative to the cell body, observed in PALMD-deficient ECs, Palmd−/− mouse aorta, and human aortic valve samples derived from patients with calcific aortic valve stenosis. In agreement with these changes in EC behavior, gene ontology analysis showed enrichment of nuclear- and cytoskeleton-related terms in PALMD-silenced ECs. Conclusions: We identify RANGAP1 as a PALMD partner in ECs. Disrupting the PALMD/RANGAP1 complex alters the subcellular localization of RANGAP1 and XPO1, and leads to nuclear arrest of the XPO1 cargoes p53 and p21, accompanied by gene regulatory changes and loss of actin-dependent nuclear resilience. Combined, these consequences of reduced PALMD expression provide a mechanistic underpinning for PALMD’s contribution to calcific aortic valve stenosis pathology.
- Published
- 2021
18. Kindlin-2 Mediates Mechanical Activation of Cardiac Myofibroblasts
- Author
-
Elena Godbout, Bernhard Wehrle-Haller, Cristina Has, Leena Bruckner-Tuderman, Andras Kapus, Dong Ok Son, Boris Hinz, Stellar Boo, Stephanie Hume, Sophie Clément, and Vincent Sarrazy
- Subjects
Male ,Mechanotransduction ,ddc:616.07 ,Mechanotransduction, Cellular ,nuclear shuttling ,Transcription (biology) ,Fibrosis ,mechanosensation ,RNA, Small Interfering ,focal adhesion ,Myofibroblasts ,Promoter Regions, Genetic ,lcsh:QH301-705.5 ,Cells, Cultured ,Microscopy ,Gene knockdown ,Cultured ,Chemistry ,Fibroblasts/cytology/metabolism ,General Medicine ,Cell biology ,Neoplasm Proteins ,Neoplasm Proteins/antagonists & inhibitors/genetics/metabolism ,Actins/genetics/metabolism ,Myofibroblasts/cytology/drug effects/metabolism ,RNA Interference ,Myofibroblast ,Adult ,Small Interfering/metabolism ,Cells ,macromolecular substances ,Fluorescence ,Article ,Promoter Regions ,Focal adhesion ,Transforming Growth Factor beta1 ,Genetic ,Myofibroblast contraction ,medicine ,Animals ,Humans ,Membrane Proteins/antagonists & inhibitors/genetics/metabolism ,ddc:612 ,Cell Nucleus ,fibrosis ,mechanical stress ,Membrane Proteins ,Fibroblasts ,medicine.disease ,Actins ,Rats ,Transforming Growth Factor beta1/pharmacology ,lcsh:Biology (General) ,Microscopy, Fluorescence ,Cell Nucleus/metabolism ,RNA ,sense organs ,Cellular ,Nuclear localization sequence - Abstract
We identify the focal adhesion protein kindlin-2 as player in a novel mechanotransduction pathway that controls profibrotic cardiac fibroblast to myofibroblast activation. Kindlin-2 is co-upregulated with the myofibroblast marker &alpha, smooth muscle actin (&alpha, SMA) in fibrotic rat hearts and in human cardiac fibroblasts exposed to fibrosis-stiff culture substrates and pro-fibrotic TGF-&beta, 1. Stressing fibroblasts using ferromagnetic microbeads, stretchable silicone membranes, and cell contraction agonists all result in kindlin-2 translocation to the nucleus. Overexpression of full-length kindlin-2 but not of kindlin-2 missing a putative nuclear localization sequence (∆NLS kindlin-2) results in increased &alpha, SMA promoter activity. Downregulating kindlin-2 with siRNA leads to decreased myofibroblast contraction and reduced &alpha, SMA expression, which is dependent on CC(A/T)-rich GG(CArG) box elements in the &alpha, SMA promoter. Lost myofibroblast features under kindlin-2 knockdown are rescued with wild-type but not ∆NLS kindlin-2, indicating that myofibroblast control by kindlin-2 requires its nuclear translocation. Because kindlin-2 can act as a mechanotransducer regulating the transcription of &alpha, SMA, it is a potential target to interfere with myofibroblast activation in tissue fibrosis.
- Published
- 2020
19. The NSL complex maintains nuclear architecture stability via lamin A/C acetylation
- Author
-
Karoutas, A., Szymanski, W., Rausch, T., Guhathakurta, S., Rog-Zielinska, E. A., Peyronnet, R., Seyfferth, J., Chen, H. R., de Leeuw, R., Herquel, B., Kimura, Hiroshi, Mittler, G., Kohl, P., Medalia, O., Korbel, J. O., Akhtar, A., University of Zurich, and Akhtar, Asifa
- Subjects
Genome instability ,Cell Nucleus/metabolism/*ultrastructure ,610 Medicine & health ,Epigenesis, Genetic ,Histones ,1307 Cell Biology ,03 medical and health sciences ,Histone H3 ,Mice ,Nuclear Proteins/genetics/*metabolism ,0302 clinical medicine ,Heterochromatin ,10019 Department of Biochemistry ,Animals ,Epigenetics ,Histones/genetics/metabolism ,Cells, Cultured ,Histone Acetyltransferases ,030304 developmental biology ,Cell Nucleus ,Mice, Knockout ,0303 health sciences ,Chemistry ,fungi ,Histone Acetyltransferases/genetics/*metabolism ,Nuclear Proteins ,Acetylation ,Cell Biology ,Fibroblasts ,Lamin Type A ,Cell biology ,Mice, Inbred C57BL ,Lamin Type A/chemistry/genetics/*metabolism ,030220 oncology & carcinogenesis ,Acetyltransferase ,Nuclear lamina ,570 Life sciences ,biology ,Lamin ,NSL complex - Abstract
While nuclear lamina abnormalities are hallmarks of human diseases, their interplay with epigenetic regulators and precise epigenetic landscape remain poorly understood. Here, we show that loss of the lysine acetyltransferase MOF or its associated NSL-complex members KANSL2 or KANSL3 leads to a stochastic accumulation of nuclear abnormalities with genomic instability patterns including chromothripsis. SILAC-based MOF and KANSL2 acetylomes identified lamin A/C as an acetylation target of MOF. HDAC inhibition or acetylation-mimicking lamin A derivatives rescue nuclear abnormalities observed in MOF-deficient cells. Mechanistically, loss of lamin A/C acetylation resulted in its increased solubility, defective phosphorylation dynamics and impaired nuclear mechanostability. We found that nuclear abnormalities include EZH2-dependent histone H3 Lys 27 trimethylation and loss of nascent transcription. We term this altered epigenetic landscape “heterochromatin enrichment in nuclear abnormalities” (HENA). Collectively, the NSL-complex-dependent lamin A/C acetylation provides a mechanism that maintains nuclear architecture and genome integrity. Karoutas et al. report lamin A/C as a non-histone target for the acetyltransferase MOF. They find that lamin A/C acetylation prevents nuclear envelope rupture and maintains nuclear integrity.
- Published
- 2019
20. Phenotype-genotype correlations in Leigh syndrome: new insights from a multicentre study of 96 patients
- Author
-
Mar Tulinius, Niklas Darin, Kalliopi Sofou, Linda De Meirleir, Johanna Uusimaa, Charalampos Tzoulis, Pirjo Isohanni, Karin Naess, Elsebet Ostergaard, Irenaeus F.M. de Coo, Tuula Lönnqvist, Laurence A. Bindoff, Neurology, Reproduction and Genetics, Neurogenetics, Clinical sciences, Research Programme for Molecular Neurology, Research Programs Unit, Anu Wartiovaara / Principal Investigator, Clinicum, Children's Hospital, University of Helsinki, Lastenneurologian yksikkö, and HUS Children and Adolescents
- Subjects
0301 basic medicine ,Male ,Cardiomyopathy ,CHILDHOOD ,CHILDREN ,DNA, Mitochondrial/genetics ,0302 clinical medicine ,ENCEPHALOMYOPATHY ,3123 Gynaecology and paediatrics ,Leigh Disease/genetics ,Genetics (clinical) ,Genetics ,1184 Genetics, developmental biology, physiology ,Phenotype ,Cohort ,Female ,medicine.symptom ,Leigh Disease ,medicine.medical_specialty ,Mitochondrial DNA ,Ataxia ,DNA ABNORMALITIES ,Mutation/genetics ,Mitochondrial disease ,Biology ,DNA/genetics ,MITOCHONDRIAL DISEASE ,DNA, Mitochondrial ,Central nervous system disease ,03 medical and health sciences ,Internal medicine ,medicine ,Humans ,Leigh disease ,Genetic Association Studies ,Cell Nucleus ,CARDIOMYOPATHY ,Genetic heterogeneity ,CLINICAL-FEATURES ,3112 Neurosciences ,Infant ,DNA ,medicine.disease ,030104 developmental biology ,NDUFS4 GENE ,Mutation ,Cell Nucleus/metabolism ,COMPLEX-I DEFICIENCY ,030217 neurology & neurosurgery ,SURF1 GENE-MUTATIONS ,Follow-Up Studies - Abstract
BackgroundLeigh syndrome is a phenotypically and genetically heterogeneous mitochondrial disorder. While some genetic defects are associated with well-described phenotypes, phenotype-genotype correlations in Leigh syndrome are not fully explored.ObjectiveWe aimed to identify phenotype-genotype correlations in Leigh syndrome in a large cohort of systematically evaluated patients.MethodsWe studied 96 patients with genetically confirmed Leigh syndrome diagnosed and followed in eight European centres specialising in mitochondrial diseases.ResultsWe found that ataxia, ophthalmoplegia and cardiomyopathy were more prevalent among patients with mitochondrial DNA defects. Patients with mutations in MT-ND and NDUF genes with complex I deficiency shared common phenotypic features, such as early development of central nervous system disease, followed by high occurrence of cardiac and ocular manifestations. The cerebral cortex was affected in patients with NDUF mutations significantly more often than the rest of the cohort. Patients with the m.8993T>G mutation in MT-ATP6 gene had more severe clinical and radiological manifestations and poorer disease outcome compared with patients with the m.8993T>C mutation.ConclusionOur study provides new insights into phenotype-genotype correlations in Leigh syndrome and particularly in patients with complex I deficiency and with defects in the mitochondrial ATP synthase.
- Published
- 2018
21. The Cell Nucleus–Metabolism and Radiosensitivity
- Author
-
Alma Howard
- Subjects
Cell nucleus ,medicine.anatomical_structure ,Chemistry ,medicine ,General Medicine ,Radiosensitivity ,Metabolism ,Cell biology - Published
- 1966
22. ReviewsThe Cell Nucleus—Metabolism and Radiosensitivity. Proceedings of a Symposium May 9–12, 1966, pp. 349 (illus.), 1966 (London, Taylor & Francis), Cloth bound—£4 10s. Paper bound—£3 15s
- Author
-
L. G. Lajtha
- Subjects
Cell nucleus ,medicine.anatomical_structure ,Philosophy ,medicine ,Radiology, Nuclear Medicine and imaging ,General Medicine ,Radiosensitivity ,Molecular biology - Published
- 1967
23. Opioid precursor protein isoform is targeted to the cell nuclei in the human brain
- Author
-
Igor Bazov, Oleg Krishtal, Jan Mulder, Hiroyuki Watanabe, Dineke S. Verbeek, Georgy Bakalkin, Tatiana Yakovleva, Henrik Druid, Kanar Alkass, G. V. Gerashchenko, Craig A. Stockmeier, Olga Kononenko, Åsa Fex Svenningsen, Oleg Dyachok, Malin Andersson, Grazyna Rajkowska, Molecular Neuroscience and Ageing Research (MOLAR), and Movement Disorder (MD)
- Subjects
0301 basic medicine ,Protein isoform ,Male ,PROENKEPHALIN ,RNA, Messenger/metabolism ,Dynorphin ,Biochemistry ,0302 clinical medicine ,Prodynorphin ,Gene expression ,Protein Isoforms ,Amino Acids ,Aged, 80 and over ,Enkephalins ,Middle Aged ,Protein Precursors/metabolism ,Nuclear localization ,Opioid Peptides ,Opioid Peptides/metabolism ,RNA splicing ,DYNORPHIN ,Female ,Protein Isoforms/metabolism ,MESSENGER-RNA ,Enkephalins/metabolism ,ENDOGENOUS LIGAND ,Signal peptide ,Adult ,Dynorphins/metabolism ,Biophysics ,Neuropeptide ,Amino Acids/metabolism ,Biology ,Human brain ,Dynorphins ,Neuropeptide precursor protein ,Article ,03 medical and health sciences ,Young Adult ,ATAXIA TYPE 23 ,Cell Line, Tumor ,TRANSCRIPTS ,Humans ,Animals ,Gene Silencing ,RNA, Messenger ,Protein Precursors ,Molecular Biology ,Caudate Nucleus/metabolism ,Aged ,Cell Nucleus ,PRODYNORPHIN GENE ,Messenger RNA ,RECEPTOR ,IDENTIFICATION ,Gene Expression Regulation/physiology ,Alternative splicing ,Gene Silencing/physiology ,Molecular biology ,Rats ,030104 developmental biology ,Gene Expression Regulation ,Cell Nucleus/metabolism ,RAT ,Caudate Nucleus ,030217 neurology & neurosurgery - Abstract
Background: Neuropeptide precursors are traditionally viewed as proteins giving rise to small neuropeptide molecules. Prodynorphin (PDYN) is the precursor protein to dynorphins, endogenous ligands for the kappa-opioid receptor. Alternative mRNA splicing of neuropeptide genes may regulate cell- and tissue-specific neuropeptide expression and produce novel protein isoforms. We here searched for novel PDYN mRNA and their protein product in the human brain.Methods: Novel PDYN transcripts were identified using nested PCR amplification of oligo(dT) selected full-length capped mRNA. Gene expression was analyzed by qRT-PCR, PDYN protein by western blotting and confocal imaging, dynorphin peptides by radioimmunoassay. Neuronal nuclei were isolated using fluorescence activated nuclei sorting (FANS) from postmortem human striatal tissue. lmmunofluorescence staining and con focal microscopy was performed for human caudate nucleus.Results: Two novel human PDYN mRNA splicing variants were identified. Expression of one of them was confined to the striatum where its levels constituted up to 30% of total PDYN mRNA. This transcript may be translated into ASP-PDYN protein lacking 13 N-terminal amino acids, a fragment of signal peptide (SP). Delta SP-PDYN was not processed to mature dynorphins and surprisingly, was targeted to the cell nuclei in a model cellular system. The endogenous PDYN protein was identified in the cell nuclei in human striatum by western blotting of isolated neuronal nuclei, and by confocal imaging.Conclusions and general significance: High levels of alternatively spliced Delta SP-PDYN mRNA and nuclear localization of PDYN protein suggests a nuclear function for this isoform of the opioid peptide precursor in human striatum. (C) 2016 Elsevier B.V. All rights reserved.
- Published
- 2017
24. Osteoclast Fusion: Time‐Lapse Reveals Involvement of CD47 and Syncytin‐1 at Different Stages of Nuclearity
- Author
-
Marie Julie Møller, Anaïs, Delaissé, Jean-Marie, and Søe, Kent
- Subjects
Cell Nucleus ,Osteoclasts/cytology ,CD47 Antigen/metabolism ,Pregnancy Proteins/metabolism ,Gene Products, env ,Osteoclasts ,CD47 Antigen ,Pregnancy Proteins ,Models, Biological ,Time-Lapse Imaging ,Cell Fusion ,Phenotype ,Original Research Articles ,Cell Nucleus/metabolism ,Gene Products, env/metabolism ,Humans ,Original Research Article - Abstract
Investigations addressing the molecular keys of osteoclast fusion are primarily based on end-point analyses. No matter if investigations are performed in vivo or in vitro the impact of a given factor is predominantly analyzed by counting the number of multi-nucleated cells, the number of nuclei per multinucleated cell or TRAcP activity. But end-point analyses do not show how the fusion came about. This would not be a problem if fusion of osteoclasts was a random process and occurred by the same molecular mechanism from beginning to end. However, we and others have in the recent period published data suggesting that fusion partners may specifically select each other and that heterogeneity between the partners seems to play a role. Therefore, we set out to directly test the hypothesis that fusion factors have a heterogenic involvement at different stages of nuclearity. Therefore, we have analyzed individual fusion events using time-lapse and antagonists of CD47 and syncytin-1. All time-lapse recordings have been studied by two independent observers. A total of 1808 fusion events were analyzed. The present study shows that CD47 and syncytin-1 have different roles in osteoclast fusion depending on the nuclearity of fusion partners. While CD47 promotes cell fusions involving mono-nucleated pre-osteoclasts, syncytin-1 promotes fusion of two multi-nucleated osteoclasts, but also reduces the number of fusions between mono-nucleated pre-osteoclasts. Furthermore, CD47 seems to mediate fusion mostly through broad contact surfaces between the partners' cell membrane while syncytin-1 mediate fusion through phagocytic-cup like structure. J. Cell. Physiol. 232: 1396-1403, 2017. © 2016 Wiley Periodicals, Inc.
- Published
- 2016
25. Nuclear fate of yeast snoRNA is determined by co-transcriptional Rnt1 cleavage
- Author
-
Pawel Grzechnik, Sylwia A. Szczepaniak, Somdutta Dhir, Anna Pastucha, Hannah Parslow, Zaneta Matuszek, Hannah E. Mischo, Joanna Kufel, and Nicholas J. Proudfoot
- Subjects
Cell Nucleus ,Ribonuclease III ,RNA Caps ,RNA, Small Nucleolar/metabolism ,Cytoplasm ,Saccharomyces cerevisiae Proteins ,urogenital system ,Science ,RNA, Fungal ,Ribonuclease III/genetics ,Saccharomyces cerevisiae ,Methylation ,Article ,Cytoplasm/metabolism ,Saccharomyces cerevisiae/genetics ,RNA, Fungal/genetics ,Ribonucleoproteins, Small Nucleolar/genetics ,Ribonucleoproteins, Small Nucleolar ,Cell Nucleus/metabolism ,RNA, Small Nucleolar ,Saccharomyces cerevisiae Proteins/genetics ,lcsh:Q ,RNA Processing, Post-Transcriptional ,lcsh:Science - Abstract
Small nucleolar RNA (snoRNA) are conserved and essential non-coding RNA that are transcribed by RNA Polymerase II (Pol II). Two snoRNA classes, formerly distinguished by their structure and ribonucleoprotein composition, act as guide RNA to target RNA such as ribosomal RNA, and thereby introduce specific modifications. We have studied the 5ʹend processing of individually transcribed snoRNA in S. cerevisiae to define their role in snoRNA biogenesis and functionality. Here we show that pre-snoRNA processing by the endonuclease Rnt1 occurs co-transcriptionally with removal of the m7G cap facilitating the formation of box C/D snoRNA. Failure of this process causes aberrant 3ʹend processing and mislocalization of snoRNA to the cytoplasm. Consequently, Rnt1-dependent 5ʹend processing of box C/D snoRNA is critical for snoRNA-dependent methylation of ribosomal RNA. Our results reveal that the 5ʹend processing of box C/D snoRNA defines their distinct pathway of maturation., Small nucleolar ribonucleoprotein complexes (snoRNP) are fundamental for ribosome biogenesis. Here the authors provide insight into the 5ʹend processing of S. cerevisiae snoRNA and its important role in downstream nuclear events.
- Published
- 2018
26. Mammalian Target of Rapamycin Complex 2 Controls CD8 T Cell Memory Differentiation in a Foxo1-Dependent Manner
- Author
-
Jean-Pierre Mach, Guerric Samson, Marten Meyer, Pedro Romero, Lianjun Zhang, Michael N. Hall, Isabel C. Lopez-Mejia, Markus A. Rüegg, Benjamin O. Tschumi, Susanne Oberle, Dietmar Zehn, Lluis Fajas, and Alena Donda
- Subjects
0301 basic medicine ,Interleukin 2 ,Transcription, Genetic ,Cellular differentiation ,Regulator ,Mechanistic Target of Rapamycin Complex 2 ,CD8-Positive T-Lymphocytes ,Biology ,mTORC2 ,General Biochemistry, Genetics and Molecular Biology ,Rictor ,03 medical and health sciences ,0302 clinical medicine ,Downregulation and upregulation ,Foxo1 ,medicine ,Animals ,Cytotoxic T cell ,lcsh:QH301-705.5 ,Cell Nucleus ,Mice, Knockout ,Forkhead Box Protein O1 ,Effector ,TOR Serine-Threonine Kinases ,Cell Differentiation ,Forkhead Transcription Factors ,infection ,Cell biology ,Mice, Inbred C57BL ,Rapamycin-Insensitive Companion of mTOR Protein ,030104 developmental biology ,lcsh:Biology (General) ,Multiprotein Complexes ,030220 oncology & carcinogenesis ,CD8-Positive T-Lymphocytes/cytology ,CD8-Positive T-Lymphocytes/immunology ,Carrier Proteins/metabolism ,Cell Differentiation/genetics ,Cell Nucleus/metabolism ,Forkhead Transcription Factors/metabolism ,Immunologic Memory/genetics ,Interleukin-2/biosynthesis ,Multiprotein Complexes/metabolism ,T-Box Domain Proteins/metabolism ,TOR Serine-Threonine Kinases/metabolism ,Cancer research ,Interleukin-2 ,Signal transduction ,Carrier Proteins ,T-Box Domain Proteins ,Immunologic Memory ,CD8 T cell ,medicine.drug - Abstract
Summary: Upon infection, antigen-specific naive CD8 T cells are activated and differentiate into short-lived effector cells (SLECs) and memory precursor cells (MPECs). The underlying signaling pathways remain largely unresolved. We show that Rictor, the core component of mammalian target of rapamycin complex 2 (mTORC2), regulates SLEC and MPEC commitment. Rictor deficiency favors memory formation and increases IL-2 secretion capacity without dampening effector functions. Moreover, mTORC2-deficient memory T cells mount more potent recall responses. Enhanced memory formation in the absence of mTORC2 was associated with Eomes and Tcf-1 upregulation, repression of T-bet, enhanced mitochondrial spare respiratory capacity, and fatty acid oxidation. This transcriptional and metabolic reprogramming is mainly driven by nuclear stabilization of Foxo1. Silencing of Foxo1 reversed the increased MPEC differentiation and IL-2 production and led to an impaired recall response of Rictor KO memory T cells. Therefore, mTORC2 is a critical regulator of CD8 T cell differentiation and may be an important target for immunotherapy interventions. : Zhang et al. demonstrate that mTORC2 deficiency favors CD8 T cell memory differentiation during the primary antigen-specific T cell response to Listeria infection. The effects result from higher Foxo1 transcriptional activity without dampening effector functions. They also show enhanced recall responses by mTORC2-deficient memory CD8 T cells. Keywords: Rictor, mTORC2, Foxo1, CD8 T cell, infection
- Published
- 2016
27. Proton irradiation orchestrates macrophage reprogramming through NFκB signaling
- Author
-
Benjamin Le Calvé, Géraldine Genard, Noelle Ninane, Tijani Tabarrant, Anne-Catherine Heuskin, Catherine Demazy, Carine Michiels, Stéphane Lucas, Antoine Fattaccioli, Sébastien Penninckx, Anne-Catherine Wéra, and Camille Huart
- Subjects
0301 basic medicine ,Cancer Research ,THP-1 Cells ,Tumor Suppressor p53-Binding Protein 1/metabolism ,Transcription Factor RelA/metabolism ,Immunology ,Macrophage polarization ,Histones/metabolism ,Radiation Tolerance ,Article ,Proinflammatory cytokine ,Histones ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,Macrophages/metabolism ,Radiation Tolerance/radiation effects ,Macrophage ,Humans ,lcsh:QH573-671 ,Cell Nucleus ,lcsh:Cytology ,Chemistry ,Macrophages ,NF-kappa B ,Transcription Factor RelA ,Cell Biology ,Cellular Reprogramming/radiation effects ,Cellular Reprogramming ,Phenotype ,IκBα ,Protein Transport ,030104 developmental biology ,Tumor progression ,Cell Nucleus/metabolism ,NF-kappa B/metabolism ,Cancer research ,Signal transduction ,Protons ,Tumor Suppressor p53-Binding Protein 1 ,Reprogramming ,Signal Transduction - Abstract
Tumor-associated macrophages (TAMs) represent potential targets for anticancer treatments as these cells play critical roles in tumor progression and frequently antagonize the response to treatments. TAMs are usually associated to an M2-like phenotype, characterized by anti-inflammatory and protumoral properties. This phenotype contrasts with the M1-like macrophages, which exhibits proinflammatory, phagocytic, and antitumoral functions. As macrophages hold a high plasticity, strategies to orchestrate the reprogramming of M2-like TAMs towards a M1 antitumor phenotype offer potential therapeutic benefits. One of the most used anticancer treatments is the conventional X-ray radiotherapy (RT), but this therapy failed to reprogram TAMs towards an M1 phenotype. While protontherapy is more and more used in clinic to circumvent the side effects of conventional RT, the effects of proton irradiation on macrophages have not been investigated yet. Here we showed that M1 macrophages (THP-1 cell line) were more resistant to proton irradiation than unpolarized (M0) and M2 macrophages, which correlated with differential DNA damage detection. Moreover, proton irradiation-induced macrophage reprogramming from M2 to a mixed M1/M2 phenotype. This reprogramming required the nuclear translocation of NFκB p65 subunit as the inhibition of IκBα phosphorylation completely reverted the macrophage re-education. Altogether, the results suggest that proton irradiation promotes NFκB-mediated macrophage polarization towards M1 and opens new perspectives for macrophage targeting with charged particle therapy.
- Published
- 2018
28. A recessive form of hyper-IgE syndrome by disruption of ZNF341-dependent STAT3 transcription and activity
- Author
-
Warren J. Leonard, Nima Rezaei, Kathryn Payne, Isabelle Meyts, Laurent Abel, Cindy S. Ma, Marianne Leruez-Ville, Janet Chou, Alain Hovnanian, Jian-Xin Lin, Simon J. Pelham, Danielle T. Avery, Matthieu Bouaziz, Bethany Pillay, Tanwir Habib, Anne Puel, Sevgi Keles, Juan Li, Isabelle Pellier, Jamel El-Benna, Bernhard Fleckenstein, Ahmet Ozen, Vivien Béziat, Ingrid Müller-Fleckenstein, Damien Chaussabel, Samaneh Zoghi, Yi Wang, Paul Gray, Matthias Titeux, Yoann Zerbib, Talal A. Chatila, Marie-Alexandra Alyanakian, Capucine Picard, Orli Wargon, Ayper Somer, Marie-Olivia Chandesris, Thibaut Leclercq, Ibtihal Benhsaien, Aziz Belkadi, Jean-Laurent Casanova, Romain Lévy, Peng Li, Geetha Rao, Ai Ing Lim, James P. Di Santo, Nico Marr, Sylvie Fraitag, Frédégonde About, Elissa K. Deenick, Bertrand Boisson, Jacinta Bustamante, Mélanie Migaud, Bodo Grimbacher, Aziz Bousfiha, Fatima Ailal, Safa Baris, Antoine Guérin, Stuart G. Tangye, Romain Guery, Ning Du, Vimel Rattina, Imagine - Institut des maladies génétiques (IMAGINE - U1163), Centre National de la Recherche Scientifique (CNRS)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), Rockefeller University [New York], National Institutes of Health [Bethesda] (NIH), Garvan Institute of Medical Research [Darlinghurst, Australia], University of New South Wales [Sydney] (UNSW), CHU Ibn Rochd [Casablanca], Université Hassan II [Casablanca] (UH2MC), Service d'Immuno-Hémato-Oncologie Pédiatrique, Centre Hospitalier Universitaire d'Angers (CHU Angers), PRES Université Nantes Angers Le Mans (UNAM)-PRES Université Nantes Angers Le Mans (UNAM), Shahid Beheshti University of Medical Sciences [Tehran] (SBUMS), Shahid Beheshti University, Universal Scientific Education and Research Network (USERN), Marmara University [Kadıköy - İstanbul], Necmettin Erbakan University [Konya, Turquie], Immunité Innée, Institut Pasteur [Paris]-Institut National de la Santé et de la Recherche Médicale (INSERM), Harvard Medical School [Boston] (HMS), Boston Children's Hospital, Centre d'infectiologie Necker-Pasteur [CHU Necker], CHU Necker - Enfants Malades [AP-HP], Sidra Medicine, Centre de recherche sur l'Inflammation (CRI (UMR_S_1149 / ERL_8252 / U1149)), Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Freiburg University Medical Center, Sydney children's hospital, Centre de Référence Déficits Immunitaires Héréditaires (CEREDIH), Assistance publique - Hôpitaux de Paris (AP-HP) (APHP)-CHU Necker - Enfants Malades [AP-HP], Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Genetic skin diseases : from disease mechanism to therapies (Equipe Inserm U1163), Centre National de la Recherche Scientifique (CNRS)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), Service de pathologie [CHU Necker], Service d'immuno-hématologie pédiatrique [CHU Necker], Laboratoire de Virologie [CHU Necker], Université Paris Descartes - Paris 5 (UPD5), Centre d'étude des Déficits Immunitaires, University Hospitals Leuven [Leuven], Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), Istanbul University, Research Center for Immunodeficiencies [Tehran, Iran], Tehran University of Medical Sciences (TUMS), University of New South Wales [Canberra Campus] (UNSW), Howard Hughes Medical Institute [New York], New York University School of Medicine, NYU System (NYU)-NYU System (NYU)-Rockefeller University [New York]-Columbia University Irving Medical Center (CUIMC), This work was supported by grants from INSERM, Paris Descartes University, Laboratoire d’Excellence Integrative Biology of Emerging Infectious Diseases (ANR-10-LABX-62-IBEID), the Jeffrey Modell Foundation Translational Research Program, the French National Research Agency (ANR, grant nos. GENCMCD-ANR-11-BSV3–005-01, HGDIFD-ANR-14-CE15-0006-01, NKIR-ANR-13-PDOC-0025-01, and EURO-CMC-ANR-14-RARE-0005-02), and grants awarded under the 'Investissement d’avenir' program (grant no. ANR-10-IAHU-01), the National Institute of Allergy and Infectious Diseases of the NIH (grant nos. U01AI109697 and R01AI127564), the Rockefeller University, the Howard Hughes Medical Institute, the St. Giles Foundation, the Institut Pasteur, and FP7, under grant agreements 305578 (PathCO) and 317057 (HOMIN). We thank the Centre de Recherche Translationnelle (Institut Pasteur) for technical assistance. V.B. is supported by the ANR (grant no. NKIR-ANR-13-PDOC-0025-01). R.L. is supported by the INSERM Ph.D. program (Poste d’Accueil INSERM), a Fulbright grant (Franco-American commission), and a Philippe Foundation scholarship. Y.Z. received the 'médaille d’or du Centre Hospitalier Universitaire d’Amiens.' Y.W. is supported by the French National Agency for Research on AIDS and Viral Hepatitis (ANRS, grant no. 13318). F. About holds a fellowship from Fondation pour la Recherche Médicale (FRM, grant no. FDM20140630671). A.G. is supported by an IFNGPHOX grant (no. ANR13-ISV3-0001-01) from ANR. B.G. was funded by BMBF (German Federal Ministry of Education and Research) grants 01E01303 and 01ZX1306F. I.M. is supported by a klinische onderzoeks-en opleidingsraad (clinical research council) grant from UZ Leuven, a klinisch onderzoeksfonds (clinical research fund) grant from KU Leuven, and an International Mobility Grant from Fonds voor Wetenschappelijk Onderzoek (fund for scientific research) Vlaanderen. C.S.M., E.K.D., and S.G.T. are supported by grants and fellowships from the National Health and Medical Research Council of Australia. C.S.M., P.G., E.K.D., and S.G.T. are members of CIRCA (Clinical Immunogenomics Research Consortia Australia), which is funded by the Office of Health and Medical Research of the NSW Government, the Jeffrey Modell Foundation, and the John Cook Brown Foundation. A.I.L. is a scholar of the Pasteur-Paris University International Ph.D. program and is supported by a Ph.D. International Training Network grant from the European Union’s Seventh Framework Program under grant agreement no. 317057 (HOMIN). T.A.C. was supported by a grant from the National Institute of Allergy and Infectious Diseases of the NIH (5R01AI065617). S.K. was supported by a grant from the Scientific and Technological Research Council of Turkey (1059B191300622). J.-X.L., P.L., N.D., and W.J.L. were supported by the Division of Intramural Research, National Heart, Lung, and Blood Institute, NIH. A.P. was supported by an AP-HP interface contract., We thank the patients and their families for participating in this study. We thank J. E. Darnell and C. Mertens for advice and for providing reagents. We thank the members of the laboratory, especially F. Jabot-Hanin and V. Pedergnana, for their valuable input on linkage analysis, L. Amar, Y. Nemirovskaya, D. Papandrea, E. Anderson, M. Woollett, C. Desvallées, C. Patissier, and M. Corrias for administrative assistance, E. Jouanguy and Y. Itan for helpful discussions, S. Boucherit for clinical data collection, S. Jacques and the Cochin genomics platform for microarray experiments, and N. Goudin and R. Desveaux of the Necker Institute Imaging Facility., Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), Garvan Institute of medical research, Immunité Innée - Innate Immunity, Institut Pasteur [Paris] (IP)-Institut National de la Santé et de la Recherche Médicale (INSERM), Institut Pasteur [Paris] (IP)-CHU Necker - Enfants Malades [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Sidra Medicine [Doha, Qatar], Université Paris Diderot - Paris 7 (UPD7)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Universitäts Klinikum Freiburg = University Medical Center Freiburg (Uniklinik), Sydney Children's hospital, Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-CHU Necker - Enfants Malades [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), Howard Hughes Medical Institute [New York] (HHMI), Howard Hughes Medical Institute (HHMI)-New York University School of Medicine, Institut Pasteur [Paris]-CHU Necker - Enfants Malades [AP-HP], Beziat, Vivien, Li, Juan, Lin, Jian-Xin, Ma, Cindy S., Li, Peng, Bousfiha, Aziz, Pellier, Isabelle, Zoghi, Samaneh, Baris, Safa, Keles, Sevgi, Gray, Paul, Du, Ning, Wang, Yi, Zerbib, Yoann, Levy, Romain, Leclercq, Thibaut, About, Fredegonde, Lim, Ai Ing, Rao, Geetha, Payne, Kathryn, Pelham, Simon J., Avery, Danielle T., Deenick, Elissa K., Pillay, Bethany, Chou, Janet, Guery, Romain, Belkadi, Aziz, Guerin, Antoine, Migaud, Melanie, Rattina, Vimel, Ailal, Fatima, Benhsaien, Ibtihal, Bouaziz, Matthieu, Habib, Tanwir, Chaussabel, Damien, Marr, Nico, El-Benna, Jamel, Grimbacher, Bodo, Wargon, Orli, Bustamante, Jacinta, Boisson, Bertrand, Mueller-Fleckenstein, Ingrid, Fleckenstein, Bernhard, Chandesris, Marie-Olivia, Titeux, Matthias, Fraitag, Sylvie, Alyanakian, Marie-Alexandra, Leruez-Ville, Marianne, Picard, Capucine, Meyts, Isabelle, Di Santo, James P., Hovnanian, Alain, Somer, Ayper, Ozen, Ahmet, Rezaei, Nima, Chatila, Talal A., Abel, Laurent, Leonard, Warren J., Tangye, Stuart G., Puel, Anne, and Casanova, Jean-Laurent
- Subjects
0301 basic medicine ,INBORN-ERRORS ,Immunoglobulin E ,MESH: STAT3 Transcription Factor/immunology ,Loss of heterozygosity ,PRECISION MEDICINE ,Transcription (biology) ,OF-FUNCTION MUTATIONS ,STAT3 ,MESH: Transcription Factors/metabolism ,CELL-DIFFERENTIATION ,MESH: Th2 Cells/metabolism ,MESH: Immunoglobulin E/immunology ,MESH: Middle Aged ,MESH: Gene Expression Regulation/immunology ,Cell Differentiation ,General Medicine ,MESH: RNA, Messenger/metabolism ,MESH: Immunoglobulin E/blood ,MESH: Zinc Fingers/genetics ,READ ALIGNMENT ,MESH: Transcription, Genetic/immunology ,MESH: Cell Nucleus/metabolism ,MESH: Young Adult ,[SDV.IMM]Life Sciences [q-bio]/Immunology ,SIGNAL TRANSDUCER ,Job Syndrome ,MESH: Homozygote ,STAT3 Transcription Factor ,Cell type ,MESH: Lymphocyte Count ,MESH: Pedigree ,MESH: STAT3 Transcription Factor/genetics ,Immunology ,Biology ,Article ,MESH: Job Syndrome/immunology ,MESH: Genes, Recessive/genetics ,DIFFERENTIAL EXPRESSION ,MESH: Genes, Recessive/immunology ,MESH: Job Syndrome/blood ,MESH: Transcription Factors/genetics ,03 medical and health sciences ,MESH: Whole Exome Sequencing ,MESH: Exons/genetics ,Humans ,Transcription factor ,Gene ,MESH: Adolescent ,MESH: Consanguinity ,MESH: Humans ,CLINICAL-FEATURES ,MESH: Th17 Cells/metabolism ,MESH: Th17 Cells/immunology ,MESH: Cytokines/immunology ,MESH: Adult ,MESH: Loss of Function Mutation ,MESH: Job Syndrome/genetics ,MESH: Cell Differentiation/genetics ,Molecular biology ,MESH: Male ,MESH: Th2 Cells/immunology ,IL-21 RECEPTOR ,030104 developmental biology ,Gene Expression Regulation ,MESH: STAT3 Transcription Factor/metabolism ,MESH: Promoter Regions, Genetic/genetics ,MESH: Cell Differentiation/immunology ,T-CELLS ,STAT protein ,biology.protein ,Th17 Cells ,MESH: Transcription Factors/immunology ,MESH: Cytokines/metabolism ,MESH: Female - Abstract
Comment in :Who regulates whom: ZNF341 is an additional player in the STAT3/TH17 song. [Sci Immunol. 2018]; International audience; Heterozygosity for human signal transducer and activator of transcription 3 (STAT3) dominant-negative (DN) mutations underlies an autosomal dominant form of hyper-immunoglobulin E syndrome (HIES). We describe patients with an autosomal recessive form of HIES due to loss-of-function mutations of a previously uncharacterized gene, ZNF341 ZNF341 is a transcription factor that resides in the nucleus, where it binds a specific DNA motif present in various genes, including the STAT3 promoter. The patients' cells have low basal levels of STAT3 mRNA and protein. The autoinduction of STAT3 production, activation, and function by STAT3-activating cytokines is strongly impaired. Like patients with STAT3 DN mutations, ZNF341-deficient patients lack T helper 17 (TH17) cells, have an excess of TH2 cells, and have low memory B cells due to the tight dependence of STAT3 activity on ZNF341 in lymphocytes. Their milder extra-hematopoietic manifestations and stronger inflammatory responses reflect the lower ZNF341 dependence of STAT3 activity in other cell types. Human ZNF341 is essential for the STAT3 transcription-dependent autoinduction and sustained activity of STAT3.
- Published
- 2018
29. Absence of the Fragile X Mental Retardation Protein results in defects of RNA editing of neuronal mRNAs in mouse
- Author
-
Caroline Lacoux, Jessica Mingardi, Daniela Bonini, Luca La Via, Claudia Bagni, Maria Zingariello, Alice Filippini, Laura Pacini, Daniela Bosisio, Laura Sancillo, Francesca Zalfa, Alessandro Barbon, Valentina Salvi, Filippini, A, Bonini, D, Lacoux, C, Pacini, L, Zingariello, M, Sancillo, L, Bosisio, D, Salvi, V, Mingardi, J, LA VIA, L, Zalfa, F, Bagni, C, Barbon, A, University of Brescia, Department of Biomedicine and Prevention, Università degli Studi di Roma Tor Vergata [Roma], Università Campus Bio-Medico di Roma, Partenaires INRAE, Università degli studi 'G. d'Annunzio' Chieti-Pescara [Chieti-Pescara] (Ud'A), Flanders Institute for Biotechnology, Lausanne University Hospital, MIUR (PRIN) [2012A9T2S9_004], Fondazione Cariplo, Associazione Italiana Sindrome X Fragile, Telethon [GGP15257], Lejeune Foundation, and La Via, L
- Subjects
Male ,0301 basic medicine ,RNA editing ,Adenosine Deaminase ,[SDV]Life Sciences [q-bio] ,Messenger ,Adenosine Deaminase/genetics ,Adenosine Deaminase/metabolism ,Animals ,Cell Nucleus/metabolism ,Cell Nucleus/ultrastructure ,Cerebral Cortex/metabolism ,Cerebral Cortex/pathology ,Disease Models, Animal ,Fragile X Mental Retardation Protein/genetics ,Fragile X Mental Retardation Protein/metabolism ,Fragile X Syndrome/genetics ,Fragile X Syndrome/metabolism ,Fragile X Syndrome/pathology ,Gene Deletion ,Hippocampus/metabolism ,Hippocampus/pathology ,Humans ,Mice ,Mice, Knockout ,Neurons/metabolism ,Neurons/pathology ,Phenotype ,Primary Cell Culture ,Protein Binding ,RNA Editing ,RNA, Messenger/genetics ,RNA, Messenger/metabolism ,RNA-Binding Proteins/genetics ,RNA-Binding Proteins/metabolism ,ADAR2 ,FMRP ,Fragile X syndrome ,RNA-binding protein ,Proximity ligation assay ,Hippocampus ,Fragile X Mental Retardation Protein ,Zebrafish ,Cerebral Cortex ,Neurons ,Settore BIO/13 ,RNA-Binding Proteins ,medicine.anatomical_structure ,Cell Nucleus ,Fragile X Syndrome ,RNA, Messenger ,Research Paper ,congenital, hereditary, and neonatal diseases and abnormalities ,Knockout ,Biology ,03 medical and health sciences ,medicine ,RNA editing, FMRP ,Molecular Biology ,Animal ,RNA ,Cell Biology ,biology.organism_classification ,FMR1 ,Molecular biology ,nervous system diseases ,Cell nucleus ,030104 developmental biology ,Disease Models ,ADAR - Abstract
The fragile X syndrome (FXS), the most common form of inherited intellectual disability, is due to the absence of FMRP, a protein regulating RNA metabolism. Recently, an unexpected function of FMRP in modulating the activity of Adenosine Deaminase Acting on RNA (ADAR) enzymes has been reported both in Drosophila and Zebrafish. ADARs are RNA-binding proteins that increase transcriptional complexity through a post-transcriptional mechanism called RNA editing. To evaluate the ADAR2-FMRP interaction in mammals we analyzed several RNA editing re-coding sites in the fmr1 knockout (KO) mice. Ex vivo and in vitro analysis revealed that absence of FMRP leads to an increase in the editing levels of brain specific mRNAs, indicating that FMRP might act as an inhibitor of editing activity. Proximity Ligation Assay (PLA) in mouse primary cortical neurons and in non-neuronal cells revealed that ADAR2 and FMRP co-localize in the nucleus. The ADAR2-FMRP co-localization was further observed by double-immunogold Electron Microscopy (EM) in the hippocampus. Moreover, ADAR2-FMRP interaction appeared to be RNA independent. Because changes in the editing pattern are associated with neuropsychiatric and neurodevelopmental disorders, we propose that the increased editing observed in the fmr1-KO mice might contribute to the FXS molecular phenotypes.
- Published
- 2017
30. A Nucleus-Encoded Chloroplast Protein Regulated by Iron Availability Governs Expression of the Photosystem I Subunit PsaA inChlamydomonas reinhardtii
- Author
-
Michel Goldschmidt-Clermont, Sylvain Loubéry, Yves Choquet, Damien Douchi, Linnka Lefebvre-Legendre, Richard Kuras, Université de Genève = University of Geneva (UNIGE), Physiologie membranaire et moléculaire du chloroplaste (PMMC), Institut de biologie physico-chimique (IBPC (FR_550)), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Biologie du Développement (LBD), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Biologie Paris Seine (IBPS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Choquet, Yves, University of Geneva [Switzerland], Sorbonne Université (SU)-Institut de biologie physico-chimique (IBPC (FR_550)), and Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Chloroplasts ,Physiology ,Iron ,Protein subunit ,Mutant ,Chlamydomonas reinhardtii ,Plant Science ,Biology ,[SDV.BBM.BM] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology ,Photosystem I ,Thylakoids ,Chloroplast Proteins/genetics/metabolism ,Chloroplast Proteins ,Thylakoids/metabolism ,Gene Expression Regulation, Plant ,ddc:570 ,Gene expression ,Botany ,Genetics ,Chloroplasts/metabolism ,Amino Acid Sequence ,ComputingMilieux_MISCELLANEOUS ,Plant Proteins ,Cell Nucleus ,Regulation of gene expression ,Photosystem I Protein Complex ,food and beverages ,[SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology ,Articles ,Plant ,biology.organism_classification ,Photosystem I Protein Complex/genetics/metabolism ,Cell biology ,Chloroplast ,ddc:580 ,Gene Expression Regulation ,Thylakoid ,Cell Nucleus/metabolism ,Plant Proteins/genetics/metabolism ,Iron/metabolism ,Chlamydomonas reinhardtii/genetics/metabolism - Abstract
The biogenesis of the photosynthetic electron transfer chain in the thylakoid membranes requires the concerted expression of genes in the chloroplast and the nucleus. Chloroplast gene expression is subjected to anterograde control by a battery of nucleus-encoded proteins that are imported in the chloroplast, where they mostly intervene at posttranscriptional steps. Using a new genetic screen, we identify a nuclear mutant that is required for expression of the PsaA subunit of photosystem I (PSI) in the chloroplast of Chlamydomonas reinhardtii. This mutant is affected in the stability and translation of psaA messenger RNA. The corresponding gene, TRANSLATION OF psaA1 (TAA1), encodes a large protein with two domains that are thought to mediate RNA binding: an array of octatricopeptide repeats (OPR) and an RNA-binding domain abundant in apicomplexans (RAP) domain. We show that as expected for its function, TAA1 is localized in the chloroplast. It was previously shown that when mixotrophic cultures of C. reinhardtii (which use both photosynthesis and mitochondrial respiration for growth) are shifted to conditions of iron limitation, there is a strong decrease in the accumulation of PSI and that this is rapidly reversed when iron is resupplied. Under these conditions, TAA1 protein is also down-regulated through a posttranscriptional mechanism and rapidly reaccumulates when iron is restored. These observations reveal a concerted regulation of PSI and of TAA1 in response to iron availability.
- Published
- 2015
31. The TRAF-interacting protein (TRAIP) is a novel E2F target with peak expression in mitosis
- Author
-
Marcel Huber, Daniel Hohl, and Christophe Chapard
- Subjects
Keratinocytes ,TRAF-Interacting Protein ,Ubiquitin-Protein Ligases ,Green Fluorescent Proteins ,Mitosis ,E2F4 Transcription Factor ,Protein degradation ,Mice ,03 medical and health sciences ,0302 clinical medicine ,E2F2 Transcription Factor ,Animals ,Humans ,E2F1 ,RNA, Messenger ,Cycloheximide ,Promoter Regions, Genetic ,E2F ,Protein kinase B ,Transcription factor ,Cell Proliferation ,030304 developmental biology ,E2F2 ,Cell Nucleus ,Protein Synthesis Inhibitors ,0303 health sciences ,biology ,Cell Cycle ,E2F transcription factor ,promoter regulation ,3T3 Cells ,Molecular biology ,Cell Nucleus/metabolism ,Cycloheximide/chemistry ,E2F1 Transcription Factor/metabolism ,E2F2 Transcription Factor/metabolism ,E2F4 Transcription Factor/metabolism ,Gene Expression Regulation, Neoplastic ,Green Fluorescent Proteins/metabolism ,HEK293 Cells ,HeLa Cells ,Keratinocytes/cytology ,Plasmids/metabolism ,Protein Biosynthesis ,Protein Synthesis Inhibitors/chemistry ,RNA, Messenger/metabolism ,Ubiquitin-Protein Ligases/metabolism ,3. Good health ,TRAIP Gene ,Oncology ,TRAIP ,030220 oncology & carcinogenesis ,biology.protein ,E2F1 Transcription Factor ,Plasmids ,Research Paper - Abstract
// Christophe Chapard 1 , Daniel Hohl 1 and Marcel Huber 1 1 Service of Dermatology, Lausanne University Hospital, Lausanne, Switzerland Correspondence: Marcel Huber, email: // Keywords : TRAF-Interacting Protein, TRAIP, E2F transcription factor, promoter regulation, cell cycle Received : October 24, 2014 Accepted : November 08, 2014 Published : January 02, 2015 Abstract The TRAF-interacting protein (TRAIP) is an E3 ubiquitin ligase required for cell proliferation. TRAIP mRNA is downregulated in human keratinocytes after inhibition of the PI3K/AKT/mTOR signaling. Since E2F transcription factors are downstream of PI3K/AKT/mTOR we investigated whether they regulate TRAIP expression. E2F1 expression significantly increased the TRAIP mRNA level in HeLa cells. Reporter assays with the 1400bp 5’-upstream promoter in HeLa cells and human keratinocytes showed that E2F1-, E2F2- and E2F4-induced upregulation of TRAIP expression is mediated by 168bp upstream of the translation start site. Mutating the E2F binding site within this fragment reduced the E2F1- and E2F2-dependent promoter activities and protein-DNA complex formation in gel shift assays. Abundance of TRAIP mRNA and protein was regulated by the cell cycle with a peak in G2/M. Expression of GFP and TRAIP-GFP demonstrated that TRAIP-GFP protein has a lower steady-state concentration than GFP despite similar mRNA levels. Cycloheximide inhibition experiments indicated that the TRAIP protein has a half-life of around four hours. Therefore, the combination of cell cycle-dependent transcription of the TRAIP gene by E2F and rapid protein degradation leads to cell cycle-dependent expression with a maximum in G2/M. These findings suggest that TRAIP has important functions in mitosis and tumorigenesis.
- Published
- 2015
32. Genomewide identification of target genes of histone methyltransferase dG9a during Drosophila embryogenesis
- Author
-
Shimaji, K., Konishi, T., Tanaka, S., Yoshida, H., Kato, Y., Ohkawa, Y., Sato, T., Suyama, M., Kimura, Hiroshi, and Yamaguchi, M.
- Subjects
Epigenomics ,Cytoplasm ,Drosophila Proteins/genetics/metabolism ,Euchromatin ,Molecular Sequence Data ,Histones/metabolism ,Embryonic Development ,Methylation ,Epigenesis, Genetic ,Histones ,Histone H3 ,Histone methylation ,Genetics ,Drosophila Proteins ,Animals ,Embryonic Development/genetics ,Epigenetics ,Histone-Lysine N-Methyltransferase/*genetics/*metabolism ,Cell Nucleus ,biology ,Drosophila embryogenesis ,Cell Biology ,Histone-Lysine N-Methyltransferase ,Cytoplasm/metabolism ,Histone ,Drosophila melanogaster ,Histone methyltransferase ,Cell Nucleus/metabolism ,biology.protein ,Histone Methyltransferases ,Transcriptome ,Protein Processing, Post-Translational - Abstract
Post-translational modification of the histone plays important roles in epigenetic regulation of various biological processes. Among the identified histone methyltransferases (HMTases), G9a is a histone H3 Lys 9 (H3K9)-specific example active in euchromatic regions. Drosophila G9a (dG9a) has been reported to feature H3K9 dimethylation activity in vivo. Here, we show that the time required for hatching of a homozygous dG9a null mutant and heteroallelic combination of dG9a null mutants is delayed, suggesting that dG9a is at least partially responsible for progression of embryogenesis. Immunocytochemical analyses of the wild-type and the dG9a null mutant flies indicated that dG9a localizes in cytoplasm up to nuclear division cycle 7 where it is likely responsible for di-methylation of nucleosome-free H3K9. From cycles 8-11, dG9a moves into the nucleus and is responsible for di-methylating H3K9 in nucleosomes. RNA-sequence analysis utilizing early wild-type and dG9a mutant embryos showed that dG9a down-regulates expression of genes responsible for embryogenesis. RNA fluorescent in situ hybridization analysis further showed temporal and spatial expression patterns of these mRNAs did not significantly change in the dG9a mutant. These results indicate that dG9a controls transcription levels of some zygotic genes without changing temporal and spatial expression patterns of the transcripts of these genes.
- Published
- 2015
33. The three-dimensional genome: regulating gene expression during pluripotency and development
- Author
-
Andrey, Guillaume and Mundlos, Stefan
- Subjects
Chromatin Immunoprecipitation ,Genome ,Enhancer Elements ,Zinc Fingers ,Genomics ,Pluripotent Stem Cells/cytology ,Transcription Factors/chemistry ,Promoter Regions ,Mice ,Genetic ,Gene Expression Regulation ,Cell Nucleus/metabolism ,Animals ,Humans ,Cell Lineage ,Developmental ,Chromatin/chemistry ,CRISPR-Cas Systems ,Genetic Engineering ,Gene Deletion - Abstract
The precise expression of genes in time and space during embryogenesis is largely influenced by communication between enhancers and promoters, which is propagated and governed by the physical proximity of these elements in the nucleus. Here, we review how chromatin domains organize the genome by guiding enhancers to their target genes thereby preventing non-specific interactions with other neighboring regions. We also discuss the dynamics of chromatin interactions between enhancers and promoters, as well as the consequent changes in gene expression, that occur in pluripotent cells and during development. Finally, we evaluate how genomic changes such as deletions, inversions and duplications affect 3D chromatin configuration overall and lead to ectopic enhancer-promoter contacts, and thus gene misexpression, which can contribute to abnormal development and disease.
- Published
- 2017
34. NEAT1 long noncoding RNA regulates transcription via protein sequestration within subnuclear bodies
- Author
-
Hirose, T., Virnicchi, G., Tanigawa, A., Naganuma, T., Li, R., Kimura, Hiroshi, Yokoi, T., Nakagawa, S., Benard, M., Fox, A. H., Pierron, G., Compartimentation et trafic intracellulaire des mRNP = Compartmentation and intracellular traffic of mRNPs (LBD-E14), Laboratoire de Biologie du Développement (LBD), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Biologie Paris Seine (IBPS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Biologie Paris Seine (IBPS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Erasmus exchange program, University of Naples (Naples, Italy), Funding Program for Next Generation World-Leading Researchers of the Japan Society for the Promotion of Science, New Energy and Industrial Technology Development Organization, Takeda Science Foundation, National Health and Medical Research Council of Australia, Medical Research Foundation of Royal Perth Hospital, Centre National de la Recherche Scientifique, Association pour la Recherche sur le Cancer, Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Biologie Paris Seine (IBPS), and Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Proteasome Endopeptidase Complex ,Transcription, Genetic ,Cell Nucleus/*metabolism/ultrastructure ,Adenosine Deaminase ,Leupeptins ,Gene Expression Regulation ,RNA, Long Noncoding/*genetics/metabolism ,RNA-binding protein ,Biology ,DNA-binding protein ,Nuclear Matrix-Associated Proteins ,Transcription (biology) ,medicine ,Humans ,Leupeptins/pharmacology ,Promoter Regions, Genetic ,Molecular Biology ,[SDV.BDD]Life Sciences [q-bio]/Development Biology ,Adenosine Deaminase/genetics/metabolism ,Cell Nucleus ,Regulation of gene expression ,Nucleoplasm ,Nuclear Functions ,RNA-Binding Proteins ,Paraspeckle ,Articles ,Cell Biology ,Molecular biology ,Proteasome Inhibitors/pharmacology ,Paraspeckles ,Cell biology ,DNA-Binding Proteins ,Cell nucleus ,Proteasome Endopeptidase Complex/metabolism ,Protein Transport ,medicine.anatomical_structure ,Octamer Transcription Factors/metabolism ,Nuclear Matrix-Associated Proteins/metabolism ,Proteolysis ,Octamer Transcription Factors ,RNA, Long Noncoding ,RNA-Binding Proteins/metabolism ,Proteasome Inhibitors ,HeLa Cells - Abstract
Paraspeckles are subnuclear structures formed around NEAT1 lncRNA. Paraspeckles became enlarged after proteasome inhibition caused by NEAT1 transcriptional activation, leading to protein sequestration into paraspeckles. The NEAT1-dependent sequestration affects the transcription of several genes, arguing for a novel role for lncRNA in gene regulation., Paraspeckles are subnuclear structures formed around nuclear paraspeckle assembly transcript 1 (NEAT1)/MENε/β long noncoding RNA (lncRNA). Here we show that paraspeckles become dramatically enlarged after proteasome inhibition. This enlargement is mainly caused by NEAT1 transcriptional up-regulation rather than accumulation of undegraded paraspeckle proteins. Of interest, however, using immuno–electron microscopy, we find that key paraspeckle proteins become effectively depleted from the nucleoplasm by 50% when paraspeckle assembly is enhanced, suggesting a sequestration mechanism. We also perform microarrays from NEAT1-knockdown cells and find that NEAT1 represses transcription of several genes, including the RNA-specific adenosine deaminase B2 (ADARB2) gene. In contrast, the NEAT1-binding paraspeckle protein splicing factor proline/glutamine-rich (SFPQ) is required for ADARB2 transcription. This leads us to hypothesize that ADARB2 expression is controlled by NEAT1-dependent sequestration of SFPQ. Accordingly, we find that ADARB2 expression is strongly reduced upon enhanced SFPQ sequestration by proteasome inhibition, with concomitant reduction in SFPQ binding to the ADARB2 promoter. Finally, NEAT1−/− fibroblasts are more sensitive to proteasome inhibition, which triggers cell death, suggesting that paraspeckles/NEAT1 attenuates the cell death pathway. These data further confirm that paraspeckles are stress-responsive nuclear bodies and provide a model in which induced NEAT1 controls target gene transcription by protein sequestration into paraspeckles.
- Published
- 2014
35. Neuroprotective intervention by interferon-γ blockade prevents CD8+ T cell–mediated dendrite and synapse loss
- Author
-
Karin Steinbach, Weldy V. Bonilla, Roland Coras, Ruth Forman, Burkhard Becher, Daniel D. Pinschewer, Doron Merkler, Wolfgang Brück, Thomas Misgeld, Werner Müller, Andreas Bergthaler, Marylise Fernandez, Mariann Vorm, Mario Kreutzfeldt, Ingmar Blümcke, Anne Fleige, Martin Kerschensteiner, University of Zurich, Merkler, Doron, and Department of Pathology and Immunology and 2 World Health Organization Collaborating Centre for Vaccine Immunology, University of Geneva, 1211 Geneva, Switzerland.
- Subjects
immunology [T-Lymphocytes, Cytotoxic] ,metabolism [Lymphocytic Choriomeningitis] ,ddc:616.07 ,CD8-Positive T-Lymphocytes ,10263 Institute of Experimental Immunology ,Synapse ,Mice ,0302 clinical medicine ,Interferon ,Lymphocytic choriomeningitis virus ,Immunology and Allergy ,Cytotoxic T cell ,Interferon gamma ,Receptors, Interferon/genetics/metabolism ,Phosphorylation ,Child ,genetics [Perforin] ,Receptors, Interferon ,Neurons ,Interferon-gamma/antagonists & inhibitors/metabolism ,0303 health sciences ,immunology [Lymphocytic choriomeningitis virus] ,metabolism [Perforin] ,Neurons/immunology/metabolism/virology ,immunology [Lymphocytic Choriomeningitis] ,3. Good health ,genetics [Receptors, Interferon] ,Protein Transport ,immunology [Dendrites] ,Antigens, CD95 ,STAT1 Transcription Factor ,medicine.anatomical_structure ,Spinal Cord ,metabolism [Neurons] ,2723 Immunology and Allergy ,metabolism [Interferon-gamma] ,STAT1 Transcription Factor/metabolism ,Signal transduction ,Signal Transduction ,medicine.drug ,Adult ,metabolism [Spinal Cord] ,Lymphocytic Choriomeningitis/immunology/metabolism/prevention & control ,virology [Neurons] ,Adolescent ,metabolism [fas Receptor] ,prevention & control [Lymphocytic Choriomeningitis] ,Immunology ,Central nervous system ,Perforin/genetics/metabolism ,610 Medicine & health ,Mice, Transgenic ,pathology [Spinal Cord] ,Lymphocytic Choriomeningitis ,Biology ,CD8-Positive T-Lymphocytes/immunology ,Neuroprotection ,antagonists & inhibitors [Interferon-gamma] ,Article ,Dendrites/immunology ,Synapses/immunology ,Interferon-gamma ,Young Adult ,03 medical and health sciences ,genetics [fas Receptor] ,medicine ,Animals ,Humans ,Lymphocytic choriomeningitis virus/immunology ,ddc:610 ,fas Receptor ,metabolism [Cell Nucleus] ,immunology [Spinal Cord] ,Spinal Cord/immunology/metabolism/pathology ,030304 developmental biology ,Cell Nucleus ,immunology [Synapses] ,2403 Immunology ,metabolism [Receptors, Interferon] ,Perforin ,immunology [CD8-Positive T-Lymphocytes] ,Cell Biology ,Dendrites ,T-Lymphocytes, Cytotoxic/immunology ,interferon gamma receptor ,CTL ,Antigens, CD95/genetics/metabolism ,metabolism [STAT1 Transcription Factor] ,Cell Nucleus/metabolism ,Synapses ,570 Life sciences ,biology ,immunology [Neurons] ,Neuroscience ,030217 neurology & neurosurgery ,030215 immunology ,T-Lymphocytes, Cytotoxic - Abstract
IFN-γ produced by CD8+ cytotoxic T cells acts on neurons to induce Stat1-associated loss of dendrites and synapses in a mouse model of viral encephalitis., Neurons are postmitotic and thus irreplaceable cells of the central nervous system (CNS). Accordingly, CNS inflammation with resulting neuronal damage can have devastating consequences. We investigated molecular mediators and structural consequences of CD8+ T lymphocyte (CTL) attack on neurons in vivo. In a viral encephalitis model in mice, disease depended on CTL-derived interferon-γ (IFN-γ) and neuronal IFN-γ signaling. Downstream STAT1 phosphorylation and nuclear translocation in neurons were associated with dendrite and synapse loss (deafferentation). Analogous molecular and structural alterations were also found in human Rasmussen encephalitis, a CTL-mediated human autoimmune disorder of the CNS. Importantly, therapeutic intervention by IFN-γ blocking antibody prevented neuronal deafferentation and clinical disease without reducing CTL responses or CNS infiltration. These findings identify neuronal IFN-γ signaling as a novel target for neuroprotective interventions in CTL-mediated CNS disease.
- Published
- 2013
36. Redistribution of the Lamin B1 genomic binding profile affects rearrangement of heterochromatic domains and SAHF formation during senescence
- Author
-
Sadaie, M., Salama, R., Carroll, T., Tomimatsu, K., Chandra, T., Young, A. R., Narita, M., Perez-Mancera, P. A., Bennett, D. C., Chong, H., and Kimura, Hiroshi
- Subjects
Senescence ,senescence ,Heterochromatin ,Histones/metabolism ,Cell Line ,Histones ,Cell Aging/*genetics ,Chromatin Assembly and Disassembly/*genetics ,Heterochromatin/chemistry/*metabolism ,Genetics ,Lamin B1 ,Cells, Cultured ,Cellular Senescence ,Cell Nucleus ,Regulation of gene expression ,epigenetics ,Lamin Type B ,biology ,Lamin Type B/genetics/*metabolism ,Chromatin Assembly and Disassembly ,Protein Structure, Tertiary ,Chromatin ,Cell biology ,Histone ,Gene Expression Regulation ,Cell Nucleus/metabolism ,embryonic structures ,biology.protein ,Nuclear lamina ,Cell aging ,Lamin ,Protein Binding ,Research Paper ,Developmental Biology - Abstract
Senescence is a stress-responsive form of stable cell cycle exit. Senescent cells have a distinct gene expression profile, which is often accompanied by the spatial redistribution of heterochromatin into senescence-associated heterochromatic foci (SAHFs). Studying a key component of the nuclear lamina lamin B1 (LMNB1), we report dynamic alterations in its genomic profile and their implications for SAHF formation and gene regulation during senescence. Genome-wide mapping reveals that LMNB1 is depleted during senescence, preferentially from the central regions of lamina-associated domains (LADs), which are enriched for Lys9 trimethylation on histone H3 (H3K9me3). LMNB1 knockdown facilitates the spatial relocalization of perinuclear H3K9me3-positive heterochromatin, thus promoting SAHF formation, which could be inhibited by ectopic LMNB1 expression. Furthermore, despite the global reduction in LMNB1 protein levels, LMNB1 binding increases during senescence in a small subset of gene-rich regions where H3K27me3 also increases and gene expression becomes repressed. These results suggest that LMNB1 may contribute to senescence in at least two ways due to its uneven genome-wide redistribution: first, through the spatial reorganization of chromatin and, second, through gene repression.
- Published
- 2013
37. Higher-Order Looping and Nuclear Organization of Tcra Facilitate Targeted RAG Cleavage and Regulated Rearrangement in Recombination Centers
- Author
-
David G. Schatz, Iannis Aifantis, Panagiotis Ntziachristos, Mariann Micsinai, Joy M. H. Wang, Ludovic Deriano, Yuval Kluger, Jeffrey A. Jeddeloh, Elphège P. Nora, Matthew Rodesch, Julie Chaumeil, Yanhong Ji, Jane A. Skok, New York University School of Medicine (NYU), New York University School of Medicine, NYU System (NYU)-NYU System (NYU), Développement lymphocytaire et Oncogénèse, Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS), Génétique et Biologie du Développement, Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut Curie [Paris]-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Roche NimbleGen Inc., Yale Cancer Center, Yale School of Medicine [New Haven, Connecticut] (YSM), Yale University [New Haven], Howard Hughes Medical Institute (HHMI), This work is supported by the National Institute ofHealth: R01GM086852 (to J.A.S.), R37AI32524 (to D.G.S.), RO1CA133379,RO1CA105129, RO1CA149655, and RO1GM088847 (to I.A.). J.A.S. is aLeukemia & Lymphoma Society (LLS) scholar. J.C. is an Irvington Institute Fellow of the Cancer Research Institute. M.M. was supported by an NSFIGERT 0333389. L.D. was an LLS Fellow. E.P.N. was supported by the FrenchMinistry of Research and the Association pour la Recherche sur le Cancer(France). I.A. is also supported by the Leukemia & Lymphoma Society (TRPgrant), The V Foundation for Cancer Research, and the Dana Foundation.D.G.S. is an Investigator, and I.A. is an Early Career Scientist of the HowardHughes Medical Institute. The authors from Roche NimbleGen, Inc. (M.J.R.and J.A.J.) recognize a competing interest in this publication as employeesof the company., Lassailly-Bondaz, Anne, Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut Curie [Paris]-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Pierre et Marie Curie - Paris 6 (UPMC), and Yale University School of Medicine
- Subjects
Genome instability ,MESH: V(D)J Recombination ,Ataxia Telangiectasia Mutated Proteins ,Inbred C57BL ,MESH: Mice, Knockout ,Tumor Suppressor Proteins/metabolism ,Mice ,0302 clinical medicine ,Transcription (biology) ,Receptors ,Recombinase ,Medicine and Health Sciences ,MESH: Animals ,MESH: Ataxia Telangiectasia Mutated Proteins ,lcsh:QH301-705.5 ,DNA-Binding Proteins/genetics/*metabolism ,Genetics ,MESH: Histones ,0303 health sciences ,MESH: Mice, Inbred CBA ,MESH: Receptors, Antigen, T-Cell, alpha-beta ,biology ,MESH: Genomic Instability ,V(D)J recombination ,Protein-Serine-Threonine Kinases/metabolism ,Chromatin ,alpha-beta/genetics/*metabolism ,Histone ,Antigen ,[SDV.IMM]Life Sciences [q-bio]/Immunology ,MESH: Cell Nucleus ,[SDV.IMM] Life Sciences [q-bio]/Immunology ,Knockout ,Cleavage (embryo) ,DNA-binding protein ,MESH: Genetic Loci ,General Biochemistry, Genetics and Molecular Biology ,Genomic Instability ,MESH: Protein-Serine-Threonine Kinases ,03 medical and health sciences ,MESH: Cell Cycle Proteins ,MESH: Mice, Inbred C57BL ,MESH: Homeodomain Proteins ,Homeodomain Proteins/genetics/*metabolism ,Animals ,MESH: Tumor Suppressor Proteins ,MESH: Mice ,Alleles ,030304 developmental biology ,MESH: DNA Damage ,Histones/genetics ,Cell Cycle Proteins/metabolism ,MESH: Alleles ,Inbred CBA ,Biology and Life Sciences ,T-Cell ,lcsh:Biology (General) ,Genetic Loci ,Cell Nucleus/metabolism ,biology.protein ,030217 neurology & neurosurgery ,MESH: DNA-Binding Proteins ,V(D)J Recombination ,DNA Damage - Abstract
International audience; V(D)J recombination is essential for generating a diverse array of B and T cell receptors that can recognize and combat foreign antigens. As with any recombination event, tight control is essential to prevent the occurrence of genetic anomalies that drive cellular transformation. One important aspect of regulation is directed targeting of the RAG recombinase. Indeed, RAG accumulates at the 3' end of individual antigen receptor loci poised for rearrangement; however, it is not known whether focal binding is involved in regulating cleavage, and what mechanisms lead to enrichment of RAG in this region. Here, we show that monoallelic looping out of the 3' end of the T cell receptor α (Tcra) locus, coupled with transcription and increased chromatin/nuclear accessibility, is linked to focal RAG binding and ATM-mediated regulation of monoallelic cleavage on looped-out 3' regions. Our data identify higher-order loop formation as a key determinant of directed RAG targeting and the maintenance of genome stability.
- Published
- 2013
- Full Text
- View/download PDF
38. Nuclear relocation of Kss1 contributes to the specificity of the mating response
- Author
-
Pelet, S.
- Subjects
Cell Nucleus ,Enzyme Activation ,Fungal Proteins ,Protein Transport ,Gene Expression Regulation, Fungal ,Alleles ,Cell Cycle Checkpoints ,Cell Nucleus/metabolism ,Fungal Proteins/metabolism ,Mitogen-Activated Protein Kinases/genetics ,Mitogen-Activated Protein Kinases/metabolism ,Models, Biological ,Protein Binding ,Signal Transduction ,Mitogen-Activated Protein Kinases ,Article - Abstract
Mitogen Activated Protein Kinases (MAPK) play a central role in transducing extra-cellular signals into defined biological responses. These enzymes, conserved in all eukaryotes, exert their function via the phosphorylation of numerous substrates located throughout the cell and by inducing a complex transcriptional program. The partitioning of their activity between the cytoplasm and the nucleus is thus central to their function. Budding yeast serves as a powerful system to understand the regulation of these fundamental biological phenomena. Under vegetative growth, the MAPK Kss1 is enriched in the nucleus of the cells. Stimulation with mating pheromone results in a rapid relocation of the protein in the cytoplasm. Activity of either Fus3 or Kss1 in the mating pathway is sufficient to drive this change in location by disassembling the complex formed between Kss1, Ste12 and Dig1. Artificial enrichment of the MAPK Kss1 in the nucleus in presence of mating pheromone alters the transcriptional response of the cells and induces a cell-cycle arrest in absence of Fus3 and Far1.
- Published
- 2016
39. A designed curved DNA sequence remarkably enhances transgene expression from plasmid DNA in mouse liver
- Author
-
Fukunaga, S., Kanda, G., Tanase, J., Harashima, H., Ohyama, T., and Kamiya, H.
- Subjects
Histones/metabolism ,intranuclear disposition ,Transgenes ,nucleosome ,Male ,Cell Nucleus/metabolism ,exogenous DNA ,Liver/metabolism ,Base Sequence ,histones ,left-handedly curved DNA ,Gene Expression ,Mice, Inbred BALB C ,Mice ,Nucleosomes/genetics ,Animals ,Plasmids/genetics - Abstract
The intranuclear disposition of plasmid DNA is extremely important for transgene expression. The interactions between the plasmid DNA and the histone proteins are one of the keys for controlling the disposition. In this study, the effects of a left-handedly curved sequence (20-40 repeated A•T tracts) on transgene expression from a plasmid were examined in vivo. A naked luciferase plasmid with the curved sequence was delivered into mouse liver by a hydrodynamics-based injection, and the luciferase activities were quantitated at various time points. Interestingly, transgene expression was markedly increased by the addition of the curved sequence. An analysis of the nucleosome positions near the left-handedly curved sequence suggested that the sequence functions as an acceptor of the histone core and allows nucleosome sliding, resulting in transcriptional activation. These results suggested that the designed curved DNA sequences could control transgene expression from plasmid DNAs in vivo.
- Published
- 2012
40. Inhibition of pyrimidine synthesis reverses viral virulence factor-mediated block of mRNA nuclear export
- Author
-
Priyabrata Das, Benjamin P. Tu, Adolfo García-Sastre, Michael G. Roth, Jef K. De Brabander, Yaming Wang, Balaji Manicassamy, Liang Zhang, Mirco Schmolke, Beatriz M. A. Fontoura, Christian V. Forst, David E. Levy, Xiaoyi Deng, Ling Cai, and Margaret A. Phillips
- Subjects
Oxidoreductases Acting on CH-CH Group Donors ,Virulence Factors ,Viral protein ,viruses ,Active Transport, Cell Nucleus ,Dihydroorotate Dehydrogenase ,RNA, Messenger/metabolism ,Viral Nonstructural Proteins ,Biology ,medicine.disease_cause ,Viral Matrix Proteins ,NXF1 ,Pyrimidines/biosynthesis ,RNA, Viral/metabolism ,03 medical and health sciences ,Dogs ,Oxidoreductases Acting on CH-CH Group Donors/antagonists & inhibitors/metabolism ,Report ,Gene expression ,medicine ,Animals ,RNA, Messenger ,Active Transport, Cell Nucleus/physiology ,Nuclear export signal ,Research Articles ,Cells, Cultured ,030304 developmental biology ,Cell Nucleus ,0303 health sciences ,Messenger RNA ,Virulence ,Viral Nonstructural Proteins/genetics/metabolism ,030302 biochemistry & molecular biology ,virus diseases ,Virulence Factors/metabolism ,Cell Biology ,Orthomyxoviridae ,biology.organism_classification ,Molecular biology ,3. Good health ,Orthomyxoviridae/genetics/metabolism ,Pyrimidines ,Vesicular stomatitis virus ,Cell Nucleus/metabolism ,Pyrimidine metabolism ,Dihydroorotate dehydrogenase ,RNA, Viral ,Viral Matrix Proteins/chemistry/metabolism - Abstract
Altering pyrimidine levels in influenza virus– or VSV-infected cells reverses the inhibitory effect of viral proteins NS1 and M on host mRNA nuclear export, restoring expression of host antiviral factors., The NS1 protein of influenza virus is a major virulence factor essential for virus replication, as it redirects the host cell to promote viral protein expression. NS1 inhibits cellular messenger ribonucleic acid (mRNA) processing and export, down-regulating host gene expression and enhancing viral gene expression. We report in this paper the identification of a nontoxic quinoline carboxylic acid that reverts the inhibition of mRNA nuclear export by NS1, in the absence or presence of the virus. This quinoline carboxylic acid directly inhibited dihydroorotate dehydrogenase (DHODH), a host enzyme required for de novo pyrimidine biosynthesis, and partially reduced pyrimidine levels. This effect induced NXF1 expression, which promoted mRNA nuclear export in the presence of NS1. The release of NS1-mediated mRNA export block by DHODH inhibition also occurred in the presence of vesicular stomatitis virus M (matrix) protein, another viral inhibitor of mRNA export. This reversal of mRNA export block allowed expression of antiviral factors. Thus, pyrimidines play a necessary role in the inhibition of mRNA nuclear export by virulence factors.
- Published
- 2012
41. A pharmaceutical study of doxorubicin-loaded PEGylated nanoparticles for magnetic drug targeting
- Author
-
Igor Chourpa, Katel Hervé, Juliette Gautier, Archibald Paillard, Pierre Dubois, Emilie Munnier, Martin Soucé, Laurence Douziech-Eyrolles, Nanomédicaments et Nanosondes, EA 6295 (NMNS), and Université de Tours (UT)
- Subjects
Cytoplasm ,Light ,[SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging ,Chemistry, Pharmaceutical ,MESH: Doxorubicin/pharmacokinetics ,Pharmaceutical Science ,02 engineering and technology ,Pharmacology ,Ferric Compounds ,01 natural sciences ,Polyethylene Glycols ,chemistry.chemical_compound ,Drug Delivery Systems ,polycyclic compounds ,Zeta potential ,Scattering, Radiation ,Magnetite Nanoparticles ,MESH: Biological Availability ,MESH: Inhibitory Concentration 50 ,Propylamines ,Chemistry ,Hydrogen-Ion Concentration ,Silanes ,021001 nanoscience & nanotechnology ,3. Good health ,MESH: Cell Nucleus/metabolism ,Drug delivery ,MESH: Doxorubicin/administration & dosage ,0210 nano-technology ,medicine.drug ,MESH: Cell Line, Tumor ,Cell Survival ,Surface Properties ,Static Electricity ,Biological Availability ,[SDV.CAN]Life Sciences [q-bio]/Cancer ,Polyethylene glycol ,010402 general chemistry ,MESH: Chemistry, Pharmaceutical ,Inhibitory Concentration 50 ,Magnetics ,[SDV.SP.MED]Life Sciences [q-bio]/Pharmaceutical sciences/Medication ,Chlorides ,Microscopy, Electron, Transmission ,Cell Line, Tumor ,medicine ,MESH: Microscopy, Fluorescence/methods ,Humans ,Distribution (pharmacology) ,Doxorubicin ,MESH: Particle Size ,Ferrous Compounds ,Isoelectric Point ,Particle Size ,[SDV.IB.BIO]Life Sciences [q-bio]/Bioengineering/Biomaterials ,Cell Nucleus ,Nitrates ,technology, industry, and agriculture ,MESH: Drug Delivery Systems/methods ,0104 chemical sciences ,Isoelectric point ,Microscopy, Fluorescence ,Targeted drug delivery ,Cancer cell ,Biophysics ,MESH: Magnetite Nanoparticles/chemistry ,MESH: Cell Survival/drug effects - Abstract
International audience; One of the new strategies to improve cancer chemotherapy is based on new drug delivery systems, like the polyethylene glycol-coated superparamagnetic iron oxide nanoparticles (PEG-SPION, thereafter called PS). In this study, PS are loaded with doxorubicin (DOX) anticancer drug, using a pre-formed DOX-Fe(2+) complex reversible at lower pH of tumour tissues and cancer cells. The DOX loaded PS (DLPS, 3% w/w DOX/iron oxide) present a hydrodynamic size around 60nm and a zeta potential near zero at physiological pH, both parameters being favourable for increased colloidal stability in biological media and decreased elimination by the immune system. At physiological pH of 7.4, 60% of the loaded drug is gradually released from the DLPS in ∼2h. The intracellular release and distribution of DOX is followed by means of confocal spectral imaging (CSI) of the drug fluorescence. The in vitro cytotoxicity of the DLPS on MCF-7 breast cancer cells is equivalent to that of a DOX solution. The reversible association of DOX to the SPION surface and the role of polymer coating on the drug loading/release are discussed, both being critical for the design of novel stealth magnetic nanovectors for chemotherapy.
- Published
- 2012
42. Nuclear phytochrome A signaling promotes phototropism in Arabidopsis
- Author
-
Christian Fankhauser, Micha Hersch, Chitose Kami, Sven Bergmann, Thierry Genoud, Andreas Hiltbrunner, and Martine Trevisan
- Subjects
0106 biological sciences ,Cytosol/metabolism ,genetic structures ,Light ,Phytochrome A/physiology ,Mutant ,Arabidopsis ,Plant Science ,01 natural sciences ,Cytosol ,Gene Expression Regulation, Plant ,Phytochrome A ,Research Articles ,Phototropism ,0303 health sciences ,Phytochrome ,Intracellular Signaling Peptides and Proteins ,Cell biology ,Phosphoproteins/metabolism ,Arabidopsis Proteins/genetics ,Phytochrome/metabolism ,Intracellular Signaling Peptides and Proteins/metabolism ,Biochemistry ,Phototropin ,Phytochrome A/genetics ,Seedlings/physiology ,Biology ,03 medical and health sciences ,Arabidopsis/physiology ,Transcription Factors/metabolism ,Arabidopsis/genetics ,Transcription factor ,030304 developmental biology ,Cell Nucleus ,Arabidopsis Proteins ,Wild type ,Membrane Proteins ,Cell Biology ,Phosphoproteins ,biology.organism_classification ,Seedlings ,Mutation ,Cell Nucleus/metabolism ,Arabidopsis Proteins/metabolism ,Arabidopsis Proteins/physiology ,Transcription Factors ,010606 plant biology & botany - Abstract
Phototropin photoreceptors (phot1 and phot2 in Arabidopsis thaliana) enable responses to directional light cues (e.g., positive phototropism in the hypocotyl). In Arabidopsis, phot1 is essential for phototropism in response to low light, a response that is also modulated by phytochrome A (phyA), representing a classical example of photoreceptor coaction. The molecular mechanisms underlying promotion of phototropism by phyA remain unclear. Most phyA responses require nuclear accumulation of the photoreceptor, but interestingly, it has been proposed that cytosolic phyA promotes phototropism. By comparing the kinetics of phototropism in seedlings with different subcellular localizations of phyA, we show that nuclear phyA accelerates the phototropic response, whereas in the fhy1 fhl mutant, in which phyA remains in the cytosol, phototropic bending is slower than in the wild type. Consistent with this data, we find that transcription factors needed for full phyA responses are needed for normal phototropism. Moreover, we show that phyA is the primary photoreceptor promoting the expression of phototropism regulators in low light (e.g., PHYTOCHROME KINASE SUBSTRATE1 [PKS1] and ROOT PHOTO TROPISM2 [RPT2]). Although phyA remains cytosolic in fhy1 fhl, induction of PKS1 and RPT2 expression still occurs in fhy1 fhl, indicating that a low level of nuclear phyA signaling is still present in fhy1 fhl.
- Published
- 2012
43. Reactive Oxygen Species (ROS)-Activated ATM-Dependent Phosphorylation of Cytoplasmic Substrates Identified by Large-Scale Phosphoproteomics Screen*
- Author
-
Jonathan W. Arthur, Mark E. Graham, Sergei Kozlov, Martin F. Lavin, Ashley J. Waardenberg, and Kasper Engholm-Keller
- Subjects
0301 basic medicine ,Proteomics ,Cytoplasm ,Ataxia Telangiectasia Mutated Proteins/metabolism ,Proteome ,DNA repair ,DNA damage ,Glutamine ,Proteome/metabolism ,Ataxia Telangiectasia Mutated Proteins ,Biochemistry ,Analytical Chemistry ,03 medical and health sciences ,chemistry.chemical_compound ,Ataxia Telangiectasia ,0302 clinical medicine ,Reactive Oxygen Species/metabolism ,medicine ,Humans ,Phosphorylation ,Molecular Biology ,Cells, Cultured ,Cell Nucleus ,Autophosphorylation ,Phosphoproteomics ,Hydrogen Peroxide ,medicine.disease ,Cell biology ,Cytoplasm/metabolism ,Glutamine/metabolism ,Oxidative Stress ,030104 developmental biology ,chemistry ,Gene Expression Regulation ,030220 oncology & carcinogenesis ,Phosphoserine ,Ataxia-telangiectasia ,Cell Nucleus/metabolism ,Ataxia Telangiectasia/metabolism ,Proteomics/methods ,Reactive Oxygen Species ,Hydrogen Peroxide/pharmacology ,Regular Articles - Abstract
Ataxia-telangiectasia, mutated (ATM) protein plays a central role in phosphorylating a network of proteins in response to DNA damage. These proteins function in signaling pathways designed to maintain the stability of the genome and minimize the risk of disease by controlling cell cycle checkpoints, initiating DNA repair, and regulating gene expression. ATM kinase can be activated by a variety of stimuli, including oxidative stress. Here, we confirmed activation of cytoplasmic ATM by autophosphorylation at multiple sites. Then we employed a global quantitative phosphoproteomics approach to identify cytoplasmic proteins altered in their phosphorylation state in control and ataxia-telangiectasia (A-T) cells in response to oxidative damage. We demonstrated that ATM was activated by oxidative damage in the cytoplasm as well as in the nucleus and identified a total of 9,833 phosphorylation sites, including 6,686 high-confidence sites mapping to 2,536 unique proteins. A total of 62 differentially phosphorylated peptides were identified; of these, 43 were phosphorylated in control but not in A-T cells, and 19 varied in their level of phosphorylation. Motif enrichment analysis of phosphopeptides revealed that consensus ATM serine glutamine sites were overrepresented. When considering phosphorylation events, only observed in control cells (not observed in A-T cells), with predicted ATM sites phosphoSerine/phosphoThreonine glutamine, we narrowed this list to 11 candidate ATM-dependent cytoplasmic proteins. Two of these 11 were previously described as ATM substrates (HMGA1 and UIMCI/RAP80), another five were identified in a whole cell extract phosphoproteomic screens, and the remaining four proteins had not been identified previously in DNA damage response screens. We validated the phosphorylation of three of these proteins (oxidative stress responsive 1(OSR1), HDGF, and ccdc82) as ATM dependent after H 2O 2 exposure, and another protein (S100A11) demonstrated ATM-dependence for translocation from the cytoplasm to the nucleus. These data provide new insights into the activation of ATM by oxidative stress through identification of novel substrates for ATM in the cytoplasm.
- Published
- 2015
44. Immunohistochemical assessment of Pax8 expression during pancreatic islet development and in human neuroendocrine tumors
- Author
-
Rocio Garcia-Carbonero, Anabel Rojas, Raphael P. H. Meier, Benoit R. Gauthier, Lourdes Gomez-Izquierdo, Carmen M. Jimenez Moreno, Nadia Cobo-Vuilleumier, Petra I. Lorenzo, Thierry Berney, Irene Delgado, Ministerio de Ciencia e Innovación (MICIN). España, Junta de Andalucía, Fundación Progreso y Salud, Ministerio de Ciencia e Innovación (España), Instituto de Salud Carlos III, Juvenile Diabetes Research Foundation International, and European Commission
- Subjects
Pathology ,endocrine system diseases ,RNA, Messenger/metabolism ,Kidney/embryology/metabolism ,Neuroendocrine tumors ,Kidney ,Neuroendocrine Tumors/metabolism/pathology ,Mice ,Paired Box Transcription Factors ,Islets of Langerhans/embryology/metabolism ,ddc:617 ,Gene Expression Regulation, Developmental ,Liver/embryology/metabolism ,Embryo, Mammalian/metabolism ,Neuroendocrine Tumors ,Medical Laboratory Technology ,medicine.anatomical_structure ,Liver ,Pax genes ,Immunohistochemistry ,Pancreas ,Tumor Markers, Biological/metabolism ,endocrine system ,medicine.medical_specialty ,Histology ,medicine.drug_class ,Cross Reactions ,Biology ,Monoclonal antibody ,Pancreatic islet ,Islets of Langerhans ,PAX8 Transcription Factor ,Biomarkers, Tumor ,medicine ,Animals ,Humans ,RNA, Messenger ,Molecular Biology ,Cell Nucleus ,Original Paper ,Antibody cross-reactivity ,Pancreas/embryology/metabolism ,Pancreatic islets ,Kidney metabolism ,Cell Biology ,Embryo, Mammalian ,medicine.disease ,Pancreatic Neoplasms ,Paired Box Transcription Factors/genetics/metabolism ,Animals, Newborn ,Cell Nucleus/metabolism ,Pancreatic Neoplasms/metabolism/pathology ,Transcription factor ,PAX8 ,Immunostaining - Abstract
This article is distributed under the terms of the Creative Commons Attribution Noncommercial License.-- et al., The paired box transcription factor Pax8 is critical for development of the eye, thyroid gland as well as the urinary and reproductive organs. In adult, Pax8 overexpression is associated with kidney, ovarian and thyroid tumors and has emerged as a specific marker for these cancers. Recently, Pax8 expression was also reported in human pancreatic islets and in neuroendocrine tumors, identifying Pax8 as a novel member of the Pax family expressed in the pancreas. Herein, we sought to provide a comprehensive analysis of Pax8 expression during pancreogenesis and in adult islets. Immunohistochemical analysis using the most employed Pax8 polyclonal antibody revealed strong nuclear staining in the developing mouse pancreas and in mature human and mouse islets. Astonishingly, Pax8 mRNA in mouse islets was undetectable while human islets exhibited low levels. These discrepancies raised the possibility of antibody cross-reactivity. This premise was confirmed by demonstrating that the polyclonal Pax8 antibody also recognized the islet-enriched Pax6 protein both by Western blotting and immunohistochemistry. Thus, in islets polyclonal Pax8 staining corresponds mainly to Pax6. In order to circumvent this caveat, a novel Pax8 monoclonal antibody was used to re-evaluate whether Pax8 was indeed expressed in islets. Surprisingly, Pax8 was not detected in neither the developing pancreas or in mature islets. Reappraisal of pancreatic neuroendocrine tumors using this Pax8 monoclonal antibody exhibited no immunostaining as compared to the Pax8 polyclonal antibody. In conclusion, Pax8 is not expressed in the pancreas and cast doubts on the value of Pax8 as a pancreatic neuroendocrine tumor marker., This work was supported by grants from the Fundacion Progreso y Salud (to B.R.G.), the Spanish Ministry of Science and Innovation, Instituto de Salud Carlos III (PI10/00871 to B.R.G) and the Juvenile Diabetes Research Foundation (9-2004-384 to E.C.I.T Plan Nacional de I+D+I 2008-2011, ISCIII (PI08/0018) co-funded by Fondos FEDER (to A.R.) and Consejería de Salud, Junta de Andalucía (PI0008 to A.R.).
- Published
- 2011
45. Keeping mRNPs in check during assembly and nuclear export
- Author
-
Françoise Stutz and Evelina Tutucci
- Subjects
DNA Replication ,Nucleocytoplasmic Transport Proteins ,Active Transport, Cell Nucleus ,Gene Expression ,Saccharomyces cerevisiae ,Biology ,03 medical and health sciences ,0302 clinical medicine ,Nuclear Matrix-Associated Proteins ,ddc:570 ,Organelle ,Gene expression ,medicine ,Humans ,Nuclear pore ,Nuclear export signal ,Molecular Biology ,030304 developmental biology ,Ribonucleoprotein ,Cell Nucleus ,Genetics ,0303 health sciences ,Ribonucleoproteins/metabolism ,DNA replication ,Cell Biology ,Nuclear Pore/metabolism ,Cell biology ,Cell nucleus ,medicine.anatomical_structure ,Gene Expression Regulation ,Ribonucleoproteins ,Nucleocytoplasmic Transport Proteins/metabolism ,Cell Nucleus/metabolism ,Nuclear Matrix-Associated Proteins/metabolism ,Nuclear Pore ,RNA Polymerase II ,Protein Processing, Post-Translational ,030217 neurology & neurosurgery - Abstract
The cell nucleus is an intricate organelle that coordinates multiple activities that are associated with DNA replication and gene expression. In all eukaryotes, it stores the genetic information and the machineries that control the production of mature and export-competent messenger ribonucleoproteins (mRNPs), a multistep process that is regulated in a spatial and temporal manner. Recent studies suggest that post-translational modifications play a part in coordinating the co-transcriptional assembly, remodelling and export of mRNP complexes through nuclear pores, adding a new level of regulation to the process of gene expression.
- Published
- 2011
46. Light-induced degradation of phyA is promoted by transfer of the photoreceptor into the nucleus
- Author
-
Christian Fankhauser and Dimitry Debrieux
- Subjects
0106 biological sciences ,Cytoplasm ,Light ,Leupeptins ,Arabidopsis ,Plant Science ,01 natural sciences ,Green Fluorescent Proteins/genetics ,Phytochrome A ,Phytochrome A/metabolism ,Cytoplasm/radiation effects ,0303 health sciences ,Microscopy, Confocal ,Phytochrome ,biology ,General Medicine ,Plants, Genetically Modified ,Cytoplasm/metabolism ,Cell biology ,Arabidopsis Proteins/genetics ,medicine.anatomical_structure ,Arabidopsis/genetics ,Arabidopsis/metabolism ,Arabidopsis Proteins/metabolism ,Blotting, Western ,Cell Nucleus/drug effects ,Cell Nucleus/metabolism ,Cysteine Proteinase Inhibitors/pharmacology ,Cytoplasm/drug effects ,Green Fluorescent Proteins/metabolism ,Leupeptins/pharmacology ,Phytochrome A/genetics ,Proteasome Endopeptidase Complex/antagonists & inhibitors ,Proteasome Endopeptidase Complex/metabolism ,Seedling/genetics ,Seedling/metabolism ,Seedlings/metabolism ,Etiolation ,Proteasome Inhibitors ,Proteasome Endopeptidase Complex ,Green Fluorescent Proteins ,Seedlings/genetics ,Cysteine Proteinase Inhibitors ,03 medical and health sciences ,Shade avoidance ,Botany ,Genetics ,medicine ,Cell Nucleus/radiation effects ,030304 developmental biology ,Cell Nucleus ,Arabidopsis Proteins ,Far-red ,15. Life on land ,biology.organism_classification ,Seedlings ,Nuclear transport ,Agronomy and Crop Science ,Nucleus ,010606 plant biology & botany - Abstract
Higher plants possess multiple members of the phytochrome family of red, far-red light sensors to modulate plant growth and development according to competition from neighbors. The phytochrome family is composed of the light-labile phyA and several light-stable members (phyB-phyE in Arabidopsis). phyA accumulates to high levels in etiolated seedlings and is essential for young seedling establishment under a dense canopy. In photosynthetically active seedlings high levels of phyA counteract the shade avoidance response. phyA levels are maintained low in light-grown plants by a combination of light-dependent repression of PHYA transcription and light-induced proteasome-mediated degradation of the activated photoreceptor. Light-activated phyA is transported from the cytoplasm where it resides in darkness to the nucleus where it is needed for most phytochrome-induced responses. Here we show that phyA is degraded by a proteasome-dependent mechanism both in the cytoplasm and the nucleus. However, phyA degradation is significantly slower in the cytoplasm than in the nucleus. In the nucleus phyA is degraded in a proteasome-dependent mechanism even in its inactive Pr (red light absorbing) form, preventing the accumulation of high levels of nuclear phyA in darkness. Thus, light-induced degradation of phyA is in part controlled by a light-regulated import into the nucleus where the turnover is faster. Although most phyA responses require nuclear phyA it might be useful to maintain phyA in the cytoplasm in its inactive form to allow accumulation of high levels of the light sensor in etiolated seedlings.
- Published
- 2010
- Full Text
- View/download PDF
47. Effect on the Ras/Raf signaling pathway of post-translational modifications of neurofibromin: In silico study of protein modification responsible for regulatory pathways
- Author
-
Daniel C. Hoessli, Afshan Kaleem, Evelyne Walker-Nasir, Ishtiaq Ahmad, Abdul Rauf Shakoori, and Nasir-ud-Din
- Subjects
In silico ,Molecular Sequence Data ,ddc:616.07 ,medicine.disease_cause ,Biochemistry ,Acetylglucosamine ,Mice ,raf Kinases/ metabolism ,medicine ,Animals ,Humans ,Amino Acid Sequence ,Phosphorylation ,Nuclear protein ,Molecular Biology ,GTPase-Activating Proteins/chemistry ,Cell Nucleus ,Neurofibromin 1 ,Acetylglucosamine/chemistry ,Sequence Homology, Amino Acid ,biology ,GTPase-Activating Proteins ,Neurofibromin 1/ chemistry ,Cell Biology ,Protein Structure, Tertiary ,Cell biology ,Ras Signaling Pathway ,Cell Nucleus/metabolism ,ras Proteins/ metabolism ,ras Proteins ,biology.protein ,raf Kinases ,Signal transduction ,Carcinogenesis ,Protein Processing, Post-Translational ,Function (biology) ,Protein Binding ,Signal Transduction - Abstract
Mapping and chemical characterization of post-translational modifications (PTMs) in proteins are critical to understand the regulatory mechanisms involving modified proteins and their role in disease. Neurofibromatosis type 1 (NF-1) is an autosomal dominantly inherited disorder, where NF1 mutations usually result in a reduced level of the tumor suppressor protein, neurofibromin (NF). NF is a multifunctional cytoplasmic protein that regulates microtubule dynamics and participates in several signaling pathways, particularly the RAS signaling pathway. NF is a Ras GTPase-activating protein (GAP) that prevents oncogenesis by converting GTP-Ras to GDP-Ras. This function of NF is regulated by phosphorylation. Interplay of phosphorylation with O-GlcNAc modification on the same or vicinal Ser/Thr residues, the Yin Yang sites, is well known in cytoplasmic and nuclear proteins. The dynamic aspects of PTMs and their interplay being difficult to follow in vivo, we undertook this in silico work to predict and define the possible role of Yin Yang sites in NF-1. Interplay of phosphorylation and O-GlcNAc modification is proposed as a mechanism controlling the Ras signaling pathway.
- Published
- 2009
48. Essential global role of CDC14 in DNA synthesis revealed by chromosome underreplication unrecognized by checkpoints in cdc14 mutants
- Author
-
Stanimir Dulev, Christelle de Renty, Alexander V. Strunnikov, Etienne Schwob, Rajvi Mehta, Ivan Minkov, Institut de Génétique Moléculaire de Montpellier (IGMM), and Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)
- Subjects
Transcription, Genetic ,Cell Nucleus Anaphase/genetics Blotting ,Essential/genetics/physiology Genome ,Cell Cycle Proteins ,Eukaryotic DNA replication ,Pre-replication complex ,S Phase ,DNA replication factor CDT1 ,0302 clinical medicine ,Chromosome Segregation ,Replication Protein A ,DNA, Fungal ,Western Cell Cycle Proteins/*genetics/metabolism Cell Nucleus/metabolism Chromatin Immunoprecipitation Chromosome Segregation Chromosomes ,Genetics ,0303 health sciences ,Genes, Essential ,Multidisciplinary ,biology ,Biological Sciences ,Active Transport ,Chromosomes, Fungal ,Genome, Fungal ,Biological *Mutation Protein Binding Protein Tyrosine Phosphatases/*genetics/metabolism Replication Protein A/genetics/metabolism S Phase/genetics Saccharomyces cerevisiae/genetics/metabolism Saccharomyces cerevisiae Proteins/*genetics/metabolism Transcription ,Protein Binding ,DNA Replication ,DNA re-replication ,Chromatin Immunoprecipitation ,Saccharomyces cerevisiae Proteins ,Blotting, Western ,Active Transport, Cell Nucleus ,Saccharomyces cerevisiae ,DNA, Ribosomal ,Models, Biological ,Ribosomal/genetics G1 Phase/genetics Genes ,03 medical and health sciences ,Replication factor C ,Genetic ,Control of chromosome duplication ,[SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology ,030304 developmental biology ,Cell Nucleus ,Fungal/genetics Genome-Wide Association Study Models ,Fungal/*biosynthesis/genetics DNA ,G1 Phase ,Licensing factor ,Mutation ,biology.protein ,Origin recognition complex ,Protein Tyrosine Phosphatases ,Anaphase ,Fungal/*genetics DNA Damage DNA Replication DNA ,030217 neurology & neurosurgery ,DNA Damage ,Genome-Wide Association Study - Abstract
The CDC14 family of multifunctional evolutionarily conserved phosphatases includes major regulators of mitosis in eukaryotes and of DNA damage response in humans. The CDC14 function is also crucial for accurate chromosome segregation, which is exemplified by its absolute requirement in yeast for the anaphase segregation of nucleolar organizers; however the nature of this essential pathway is not understood. Upon investigation of the rDNA nondisjunction phenomenon, it was found that cdc14 mutants fail to complete replication of this locus. Moreover, other late-replicating genomic regions (10% of the genome) are also underreplicated in cdc14 mutants undergoing anaphase. This selective genome-wide replication defect is due to dosage insufficiency of replication factors in the nucleus, which stems from two defects, both contingent on the reduced CDC14 function in the preceding mitosis. First, a constitutive nuclear import defect results in a drastic dosage decrease for those replication proteins that are regulated by nuclear transport. Particularly, essential RPA subunits display both lower mRNA and protein levels, as well as abnormal cytoplasmic localization. Second, the reduced transcription of MBF and SBF-controlled genes in G1 leads to the reduction in protein levels of many proteins involved in DNA replication. The failure to complete replication of late replicons is the primary reason for chromosome nondisjunction upon CDC14 dysfunction. As the genome-wide slow-down of DNA replication does not trigger checkpoints [Lengronne A, Schwob E (2002) Mol Cell 9:1067–1078], CDC14 mutations pose an overwhelming challenge to genome stability, both generating chromosome damage and undermining the checkpoint control mechanisms.
- Published
- 2009
49. Sfp1 Interaction with TORC1 and Mrs6 Reveals Feedback Regulation on TOR Signaling
- Author
-
Harri Lempiäinen, Jörg Urban, Gustav Ammerer, David Shore, Aino Uotila, Robbie Loewith, and Ilse Dohnal
- Subjects
Chromatin Immunoprecipitation ,Protein-Serine-Threonine Kinases/genetics/metabolism ,Saccharomyces cerevisiae Proteins ,TORC1 signaling ,Ribosome biogenesis ,Saccharomyces cerevisiae ,Protein Serine-Threonine Kinases ,Saccharomyces cerevisiae Proteins/genetics/metabolism ,Biology ,Feedback, Physiological/physiology ,Saccharomyces cerevisiae/genetics/growth & development/metabolism ,ddc:570 ,Immunoprecipitation ,TOR complex ,Cycloheximide ,Phosphorylation ,Promoter Regions, Genetic ,Molecular Biology ,Adaptor Proteins, Signal Transducing ,Cell Nucleus ,Feedback, Physiological ,Sirolimus ,Sirolimus/pharmacology ,Cell Biology ,Promoter Regions, Genetic/genetics ,Cell biology ,TOR signaling ,Transport protein ,DNA-Binding Proteins ,DNA-Binding Proteins/genetics/metabolism ,Cell Nucleus/metabolism ,Cycloheximide/pharmacology ,Rab ,Signal transduction - Abstract
Ribosome biogenesis drives cell growth, and the large transcriptional output underlying this process is tightly regulated. The Target of Rapamycin (TOR) kinase is part of a highly conserved signaling pathway linking nutritional and stress signals to regulation of ribosomal protein (RP) and ribosome biogenesis (Ribi) gene transcription. In Saccharomyces cerevisiae, one of the downstream effectors of TOR is Sfp1, a transcriptional activator that regulates both RP and Ribi genes. Here, we report that Sfp1 interacts directly with TOR complex 1 (TORC1) in a rapamycin-regulated manner, and that phosphorylation of Sfp1 by this kinase complex regulates its function. Sfp1, in turn, negatively regulates TORC1 phosphorylation of Sch9, another key TORC1 target that acts in parallel with Sfp1, revealing a feedback mechanism controlling the activity of these proteins. Finally, we show that the Sfp1-interacting protein Mrs6, a Rab escort protein involved in membrane trafficking, regulates both Sfp1 nuclear localization and TORC1 signaling.
- Published
- 2009
50. Glucocorticoids and lithium reciprocally regulate the proliferation of adult dentate gyrus-derived neural precursor cells through GSK-3beta and beta-catenin/TCF pathway
- Author
-
Boku, Shuken, Nakagawa, Shin, Masuda, Takahiro, Nishikawa, Hiroyuki, Kato, Akiko, Kitaichi, Yuji, Inoue, Takeshi, and Koyama, Tsukasa
- Subjects
Neurogenesis ,Dentate Gyrus/metabolism ,Male ,Stress ,Hippocampus ,Neurogenesis/drug effects ,Dexamethasone ,Wnt ,Aminophenols/pharmacology ,Dentate Gyrus/drug effects ,Phosphorylation/drug effects ,Cell Proliferation/drug effects ,Maleimides/pharmacology ,Quercetin/pharmacology ,TCF Transcription Factors/metabolism ,beta Catenin/drug effects ,Adult Stem Cells/drug effects ,beta Catenin/metabolism ,Cyclin D1/drug effects ,Dexamethasone/pharmacology ,Cells, Cultured ,Rats ,Cell Differentiation/drug effects ,Mood stabilizer ,Stem Cells/metabolism ,Cell Nucleus/metabolism ,Rats, Sprague-Dawley ,Active Transport, Cell Nucleus/drug effects ,Lithium/pharmacology ,Glycogen Synthase Kinase 3/metabolism ,Animals - Abstract
Adult hippocampal neurogenesis is decreased in rodent models for stress-related disorders at least partly through an elevated level of glucocorticoids. On the other hand, the mood stabilizer lithium (Li) commonly used for their treatment increases it. This effect is thought to be one of the therapeutic actions of Li, but the molecular mechanism has been poorly understood. Here we established the culture system of adult rat dentate gyrus-derived neural precursor cells (ADPs) and examined the effects of dexamethasone (DEX), an agonist of glucocorticoids receptor, and Li on ADP proliferation. It is possible for ADP to be a type 2a cell, which corresponds to the second stage in a model of four differentiation stages in adult hippocampal neural precursor cells. DEX decreased ADP proliferation, but Li did not have any effect on it. However, Li recovered ADP proliferation decreased by DEX. The recovery effect of Li was abolished by quercetin, an inhibitor of beta-catenin/TCF pathway. The intranuclear translocation of beta-catenin and expression of cyclin D1 are reciprocally regulated by DEX and Li in a way similar to proliferation. In addition, DEX increased the phosphorylation of Tyr(216), which renders glycogen synthase kinase-3beta (GSK-3beta) active on it. These results suggest that GSK-3beta and beta-catenin/TCF pathway might be important in the reciprocal effects between DEX and Li on ADP proliferation and are new targets of therapeutic agents for stress-related disorders.
- Published
- 2009
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.