705 results on '"nucleoporins"'
Search Results
2. NUP155 and NDC1 interaction in NSCLC: a promising target for tumor progression.
- Author
-
Li, Kai-Min, Meng, Li-Fei, Yang, Zhi-Hao, and Hu, Wen-Tao
- Subjects
NUCLEAR pore complex ,NUCLEOPORINS ,SURVIVAL analysis (Biometry) ,HEPATOCELLULAR carcinoma ,FAMILY roles ,BREAST - Abstract
Background: NUP155 was reported to involve breast invasive carcinoma and hepatocellular carcinoma. We hypothesized that NUP155 and NDC1impacted the progression of NSCLC. Methods: The dataset was analyzed to find differentially expressed genes. Functional enrichment analysis and Kaplan-Meier survival analysis were performed for differentially expressed genes. Western blot, Clone formation assay, Transwell assay and CCK-8 assay were performed to determine the performance and role of the target gene in NSCLC. Results: The research found that the NUP family played a role in various diseases. Differential expression analysis and survival analysis were performed to identify 6 related-genes, including NUP155, NDC1, KPNA2, MAD2L1, NUP62CL, and POM121L2NUP155 and NDC1 could interact with NUP53, respectively. This effect was necessary to complete the assembly of the nuclear pore complex. Conclusion: NUP155 interacted with NDC1 to complete the assembly of the nuclear pore complex, which promoted the development of NSCLC. Our study demonstrated that NUP155 was expected to be a potential target for the treatment of NSCLC. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
3. Deciphering the intrinsically disordered characteristics of the FG-Nups through the lens of polymer physics.
- Author
-
Matsuda, Atsushi, Mansour, Abdullah, and Mofrad, Mohammad R. K.
- Subjects
- *
NUCLEAR pore complex , *SMALL molecules , *NUCLEAR proteins , *NUCLEOPORINS , *PERMEABILITY - Abstract
The nuclear pore complex (NPC) is a critical gateway regulating molecular transport between the nucleus and cytoplasm. It allows small molecules to pass freely, while larger molecules require nuclear transport receptors to traverse the barrier. This selective permeability is maintained by phenylalanine-glycine-rich nucleoporins (FG-Nups), intrinsically disordered proteins that fill the NPC's central channel. The disordered and flexible nature of FG-Nups complicates their spatial characterization with conventional structural biology techniques. To address this challenge, polymer physics offers a valuable framework for describing FG-Nup behavior, reducing their complex structures to a few key parameters. In this review, we explore how polymer physics models FG-Nups using these parameters and discuss experimental efforts to quantify them in various contexts, providing insights into the conformational properties of FG-Nups. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
4. Cytoplasmic nucleoporin assemblage: the cellular artwork in physiology and disease.
- Author
-
Lin, Junyan and Sumara, Izabela
- Subjects
- *
NUCLEAR pore complex , *NUCLEOCYTOPLASMIC interactions , *NUCLEAR transport (Cytology) , *NUCLEOPORINS , *HOMEOSTASIS , *NUCLEAR membranes - Abstract
Nucleoporins, essential proteins building the nuclear pore, are pivotal for ensuring nucleocytoplasmic transport. While traditionally confined to the nuclear envelope, emerging evidence indicates their presence in various cytoplasmic structures, suggesting potential non-transport-related roles. This review consolidates findings on cytoplasmic nucleoporin assemblies across different states, including normal physiological conditions, stress, and pathology, exploring their structural organization, formation dynamics, and functional implications. We summarize the current knowledge and the latest concepts on the regulation of nucleoporin homeostasis, aiming to enhance our understanding of their unexpected roles in physiological and pathological processes. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
5. Nup358 restricts ER-mitochondria connectivity by modulating mTORC2/Akt/GSK3β signalling.
- Author
-
Kalarikkal, Misha, Saikia, Rimpi, Oliveira, Lizanne, Bhorkar, Yashashree, Lonare, Akshay, Varshney, Pallavi, Dhamale, Prathamesh, Majumdar, Amitabha, and Joseph, Jomon
- Abstract
ER–mitochondria contact sites (ERMCSs) regulate processes, including calcium homoeostasis, energy metabolism and autophagy. Previously, it was shown that during growth factor signalling, mTORC2/Akt gets recruited to and stabilizes ERMCSs. Independent studies showed that GSK3β, a well-known Akt substrate, reduces ER–mitochondria connectivity by disrupting the VAPB–PTPIP51 tethering complex. However, the mechanisms that regulate ERMCSs are incompletely understood. Here we find that annulate lamellae (AL), relatively unexplored subdomains of ER enriched with a subset of nucleoporins, are present at ERMCSs. Depletion of Nup358, an AL-resident nucleoporin, results in enhanced mTORC2/Akt activation, GSK3β inhibition and increased ERMCSs. Depletion of Rictor, a mTORC2-specific subunit, or exogenous expression of GSK3β, was sufficient to reverse the ERMCS-phenotype in Nup358-deficient cells. We show that growth factor-mediated activation of mTORC2 requires the VAPB–PTPIP51 complex, whereas, Nup358's association with this tether restricts mTORC2/Akt signalling and ER–mitochondria connectivity. Expression of a Nup358 fragment that is sufficient for interaction with the VAPB–PTPIP51 complex suppresses mTORC2/Akt activation and disrupts ERMCSs. Collectively, our study uncovers a novel role for Nup358 in controlling ERMCSs by modulating the mTORC2/Akt/GSK3β axis. Synopsis: Nup358-positive annulate lamellae (AL) structures are present at ER-mitochondria contact sites (ERMCSs). Nup358 restricts growth factor mediated stabilization of ERMCSs by modulating mTORC2/Akt/GSK3β pathway. Annulate lamellae (AL) are present at ER-mitochondria contact sites. Depletion of Nup358, an AL-resident nucleoporin, leads to increased connectivity between ER and mitochondria. Nup358 suppresses growth factor-dependent activation of mTORC2/Akt pathway and thereby facilitates GSK3β activity to limit the ERMCSs. Nup358-positive annulate lamellae (AL) structures are present at ER-mitochondria contact sites (ERMCSs). Nup358 restricts growth factor mediated stabilization of ERMCSs by modulating mTORC2/Akt/GSK3β pathway. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
6. Interdependence between Nuclear Pore Gatekeepers and Genome Caretakers: Cues from Genome Instability Syndromes.
- Author
-
Larizza, Lidia and Colombo, Elisa Adele
- Subjects
- *
NUCLEAR pore complex , *WERNER'S syndrome , *NUCLEOPORINS , *SYMPTOMS , *DNA damage - Abstract
This review starts off with the first germline homozygous variants of the Nucleoporin 98 gene (NUP98) in siblings whose clinical presentation recalls Rothmund–Thomson (RTS) and Werner (WS) syndromes. The progeroid phenotype caused by a gene associated with haematological malignancies and neurodegenerative disorders primed the search for interplay between caretakers involved in genome instability syndromes and Nuclear Pore Complex (NPC) components. In the context of basic information on NPC architecture and functions, we discuss the studies on the interdependence of caretakers and gatekeepers in WS and Hereditary Fibrosing Poikiloderma (POIKTMP), both entering in differential diagnosis with RTS. In WS, the WRN/WRNIP complex interacts with nucleoporins of the Y-complex and NDC1 altering NPC architecture. In POIKTMP, the mutated FAM111B, recruited by the Y-complex's SEC13 and NUP96, interacts with several Nups safeguarding NPC structure. The linkage of both defective caretakers to the NPC highlights the attempt to activate a repair hub at the nuclear periphery to restore the DNA damage. The two separate WS and POIKTMP syndromes are drawn close by the interaction of their damage sensors with the NPC and by the shared hallmark of short fragile telomeres disclosing a major role of both caretakers in telomere maintenance. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
7. NUP155 and NDC1 interaction in NSCLC: a promising target for tumor progression
- Author
-
Kai-Min Li, Li-Fei Meng, Zhi-Hao Yang, and Wen-Tao Hu
- Subjects
NUP155 ,NDC1 ,NSCLC ,nucleoporins ,nuclear pore complex ,Therapeutics. Pharmacology ,RM1-950 - Abstract
BackgroundNUP155 was reported to involve breast invasive carcinoma and hepatocellular carcinoma. We hypothesized that NUP155 and NDC1impacted the progression of NSCLC.MethodsThe dataset was analyzed to find differentially expressed genes. Functional enrichment analysis and Kaplan-Meier survival analysis were performed for differentially expressed genes. Western blot, Clone formation assay, Transwell assay and CCK-8 assay were performed to determine the performance and role of the target gene in NSCLC.ResultsThe research found that the NUP family played a role in various diseases. Differential expression analysis and survival analysis were performed to identify 6 related-genes, including NUP155, NDC1, KPNA2, MAD2L1, NUP62CL, and POM121L2NUP155 and NDC1 could interact with NUP53, respectively. This effect was necessary to complete the assembly of the nuclear pore complex.ConclusionNUP155 interacted with NDC1 to complete the assembly of the nuclear pore complex, which promoted the development of NSCLC. Our study demonstrated that NUP155 was expected to be a potential target for the treatment of NSCLC.
- Published
- 2024
- Full Text
- View/download PDF
8. A mechanistic insight into cancer progression mediated by Nucleoporins.
- Author
-
Jahangiri, Leila
- Subjects
- *
NUCLEAR pore complex , *CELL cycle regulation , *TUMOR microenvironment , *NUCLEOPORINS , *CHIMERIC proteins - Abstract
• Nucleporins can promote cancer progression by affecting nuclear trafficking, fusion proteins, tumour suppressors, signalling pathways, tumour microenvironment, nucleosomes and chromatin processes. • This review manuscript highlights the mechanisms which underlie each of these 5 aspects including removing inhibitors from the nucleus, regulation of transcription, translation, chromatin topology, cell cycle regulation, protein stabilisation, the cytoskeleton and altering the tumour microenvironment among others. • Understanding the mechanisms by which nucleoporins affect cancer progression can improve therapy. The nuclear pore complexes are essential for cellular and molecular processes such as trafficking between the cytoplasm and the nucleus, chromatin, transcriptional outputs, and DNA damage repair. Nucleoporins, components of nuclear pore complexes, have been linked to cancer through nucleo-cytoplasmic cargo trafficking, cell division, signalling pathways, chromatin-related processes, and protein stability and degradation. This study aims to understand how nucleoporins specifically contribute to cancer proliferation and progression across various cancer types. Accordingly, angles such as nuclear trafficking, fusion proteins, tumour suppressors, signalling pathways, tumour microenvironment, nucleosomes, and chromatin processes were found to bridge the function of nucleoporins and cancer progression, and the underlying mechanisms have been analysed in this study. A deep understanding of the function of nucleoporins in cancer progression will pave the way for the effective targeting of these molecules for therapeutic gain. Improved treatment responses can enhance the quality of life of cancer patients. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
9. Unexplored Cdc42 functions at the budding yeast nucleus suggested by subcellular localization
- Author
-
Lu, Michelle S and Drubin, David G
- Subjects
Biochemistry and Cell Biology ,Biological Sciences ,Underpinning research ,1.1 Normal biological development and functioning ,Generic health relevance ,Saccharomycetales ,Saccharomyces cerevisiae ,Cell Division ,Cell Nucleus ,rho GTP-Binding Proteins ,Cell Polarity ,Saccharomyces cerevisiae Proteins ,CDC42 ,nucleopodia ,nucleoporins ,nucleus-vacuole junction ,vacuole ,Pharmacology and Pharmaceutical Sciences ,Biochemistry and cell biology - Abstract
In budding yeast, the Rho-family GTPase Cdc42 has several functions that depend on its subcellular localization and the cell cycle stage. During bud formation, Cdc42 localizes to the plasma membrane at the bud tip and bud neck where it carries out functions in actin polymerization, spindle positioning, and exocytosis to ensure proper polarity development. Recent live-cell imaging analysis revealed a novel localization of Cdc42 to a discrete intracellular focus associated with the vacuole and nuclear envelope. The discovery of this novel Cdc42 localization led to the identification of a new function in ESCRT-mediated nuclear envelope sealing. However, other aspects of this intracellular localization and its functional implications were not explored. Here, we further characterize the Cdc42 focus and present several novel observations that suggest possible additional Cdc42 functions at the nucleus, including nucleus-vacuole junction formation, nuclear envelope tethering, nuclear migration, and nucleopodia formation.
- Published
- 2022
10. Comprehensive structure and functional adaptations of the yeast nuclear pore complex.
- Author
-
Akey, Christopher W, Singh, Digvijay, Ouch, Christna, Echeverria, Ignacia, Nudelman, Ilona, Varberg, Joseph M, Yu, Zulin, Fang, Fei, Shi, Yi, Wang, Junjie, Salzberg, Daniel, Song, Kangkang, Xu, Chen, Gumbart, James C, Suslov, Sergey, Unruh, Jay, Jaspersen, Sue L, Chait, Brian T, Sali, Andrej, Fernandez-Martinez, Javier, Ludtke, Steven J, Villa, Elizabeth, and Rout, Michael P
- Subjects
Nuclear Envelope ,Nuclear Pore ,Saccharomyces cerevisiae ,Nuclear Pore Complex Proteins ,Saccharomyces cerevisiae Proteins ,Reproducibility of Results ,Adaptation ,Physiological ,Amino Acid Sequence ,Amino Acid Motifs ,Fluorescence ,Molecular Docking Simulation ,Protein Domains ,NPC evolution ,Nuclear pore complex ,cryo-electron microscopy ,cryo-electron tomography ,inner ring dilation ,nuclear basket ,nucleocytoplasmic transport ,nucleoporins ,structural isoforms ,1.1 Normal biological development and functioning ,Generic health relevance ,Biological Sciences ,Medical and Health Sciences ,Developmental Biology - Abstract
Nuclear pore complexes (NPCs) mediate the nucleocytoplasmic transport of macromolecules. Here we provide a structure of the isolated yeast NPC in which the inner ring is resolved by cryo-EM at sub-nanometer resolution to show how flexible connectors tie together different structural and functional layers. These connectors may be targets for phosphorylation and regulated disassembly in cells with an open mitosis. Moreover, some nucleoporin pairs and transport factors have similar interaction motifs, which suggests an evolutionary and mechanistic link between assembly and transport. We provide evidence for three major NPC variants that may foreshadow functional specializations at the nuclear periphery. Cryo-electron tomography extended these studies, providing a model of the in situ NPC with a radially expanded inner ring. Our comprehensive model reveals features of the nuclear basket and central transporter, suggests a role for the lumenal Pom152 ring in restricting dilation, and highlights structural plasticity that may be required for transport.
- Published
- 2022
11. NDC1 promotes hepatocellular carcinoma tumorigenesis by targeting BCAP31 to activate PI3K/AKT signaling.
- Author
-
Liu, Ya‐ping, Guo, Gang, Ren, Mudan, Li, Ya‐rui, Guo, Dan, She, Jun‐jun, and He, Shui‐xiang
- Subjects
PI3K/AKT pathway ,NUCLEOPORINS ,NEOPLASTIC cell transformation ,MASS spectrometers ,MULTIVARIATE analysis - Abstract
Hepatocellular carcinoma (HCC) is among the world's worst malignancies. Nuclear division cycle 1 (NDC1) is an essential membrane‐integral nucleoporin, found in this study to be significantly increased in primary HCC. A multivariate analysis revealed that higher NDC1 expression was linked to worse outcome in HCC patients. Mouse xenograft tumors overexpressing NDC1 grew rapidly, and HCC cells overexpressing NDC1 showed enhanced proliferation, invasion, and migration in vitro. In contrast, knocking down NDC1 had the opposite effects in vitro. Furthermore, co‐immunoprecipitation and liquid chromatograph mass spectrometer analyses revealed that NDC1 activated PI3K/AKT signaling by interacting with BCAP31. In summary, NDC1 and BCAP31 cooperate to promote the PI3K/AKT pathway, which is essential for HCC carcinogenesis. This suggests that NDC1 is predictive of prognosis in HCC. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
12. HIV-1 capsid shape, orientation, and entropie elasticity regulate translocation into the nuclear pore complex.
- Author
-
Hudait, Arpa and Voth, Gregory A.
- Subjects
- *
NUCLEAR pore complex , *HIV , *LIFE cycles (Biology) , *ELASTICITY , *NUCLEOPORINS - Abstract
Nuclear import and uncoating of the viral capsid are critical steps in the HIV-1 life cycle that serve to transport and release genomic material into the nucleus. Viral core import involves translocating the HIV-1 capsid at the nuclear pore complex (NPC). Notably, the central channel of the NPC appears to often accommodate and allow passage of intact HIV-1 capsid, though mechanistic details of the process remain to be fully understood. Here, we investigate the molecular interactions that operate in concert between the HIV-1 capsid and the NPC that regulate capsid translocation through the central channel. To this end, we develop a "bottom-up" coarse-grained (CG) model of the human NPC from recently released cryo-electron tomography structure and then construct composite membrane-embedded CG NPC models. We find that successful translocation from the cytoplasmic side to the NPC central channel is contingent on the compatibility of the capsid morphology and channel dimension and the proper orientation of the capsid approach to the channel from the cytoplasmic side. The translocation dynamics is driven by maximizing the contacts between phenylalanine-glycine nucleoporins at the central channel and the capsid. For the docked intact capsids, structural analysis reveals correlated striated patterns of lattice disorder likely related to the intrinsic capsid elasticity. Uncondensed genomic material inside the docked capsid augments the overall lattice disorder of the capsid. Our results suggest that the intrinsic "elasticity" can also aid the capsid to adapt to the stress and remain structurally intact during translocation. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
13. The scaffold nucleoporins SAR1 and SAR3 are essential for proper meiotic progression in Arabidopsis thaliana.
- Author
-
Fernández-Jiménez, Nadia, Martinez-Garcia, Marina, Varas, Javier, Gil-Dones, Félix, Luis Santos, Juan, and Pradillo, Mónica
- Subjects
NUCLEAR pore complex ,MEIOSIS ,NUCLEOPORINS ,ARABIDOPSIS thaliana ,NUCLEAR membranes - Abstract
Nuclear Pore Complexes (NPCs) are embedded in the nuclear envelope (NE), regulating macromolecule transport and physically interacting with chromatin. The NE undergoes dramatic breakdown and reformation during plant cell division. In addition, this structure has a specific meiotic function, anchoring and positioning telomeres to facilitate the pairing of homologous chromosomes. To elucidate a possible function of the structural components of the NPCs in meiosis, we have characterized several Arabidopsis lines with mutations in genes encoding nucleoporins belonging to the outer ring complex. Plants defective for either SUPPRESSOR OF AUXIN RESISTANCE1 (SAR1, also called NUP160) or SAR3 (NUP96) present condensation abnormalities and SPO11-dependent chromosome fragmentation in a fraction of meiocytes, which is increased in the double mutant sar1 sar3. We also observed these meiotic defects in mutants deficient in the outer ring complex protein HOS1, but not in mutants affected in other components of this complex. Furthermore, our findings may suggest defects in the structure of NPCs in sar1 and a potential link between the meiotic role of this nucleoporin and a component of the RUBylation pathway. These results provide the first insights in plants into the role of nucleoporins in meiotic chromosome behavior. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
14. A survey of the specificity and mechanism of 1,6 hexanediol-induced disruption of nuclear transport.
- Author
-
Barrientos, Elizabeth C. Riquelme, Otto, Tegan A., Mouton, Sara N., Steen, Anton, and Veenhoff, Liesbeth M.
- Subjects
- *
NUCLEAR transport (Cytology) , *NUCLEAR pore complex , *SACCHAROMYCES cerevisiae , *ALIPHATIC alcohols , *NUCLEOPORINS - Abstract
Selective transport through the nuclear pore complex (NPC) depends on the dynamic binding of FG-repeat containing nucleoporins, the FG-nups, with each other and with Karyopherins (Kaps). Here, we assessed the specificity and mechanism by which the aliphatic alcohol 1,6-hexanediol (1,6HD) disrupts the permeability barrier of NPCs in live baker's yeast cells. After a 10-minute exposure to 5% 1,6HD, no notable changes were observed in cell growth, cytosolic pH and ATP levels, or the appearance of organelles. However, effects on the cytoskeleton and Hsp104 were noted. 1,6HD clearly affected the NPC permeability barrier, allowing passive nuclear entry of a 177kDa reporter protein that is normally confined to the cytosol. Moreover, multiple Kaps were displaced from NPCs, and the displacement of Kap122-GFP correlated with the observed passive permeability changes. 1,6HD thus temporarily permeates NPCs, and in line with Kap-centric models, the mechanism includes the release of numerous Kaps from the NPCs. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
15. Architecture and composition of plant nucleopore complexes, comparisons with putative homologs across kingdoms.
- Author
-
Grandhi, Rohith, Carrillo, Ingrid Berenice Sanchez, Synytsia, Mariia, and Germain, Hugo
- Abstract
Nucleopore Complexes are intricate protein assemblies composed of diverse nucleoporins, which serve as crucial mediators for the bidirectional movement of molecules between the nucleus and cytosol. These nucleoporins share both structural and functional characteristics across yeast, mammals, and plants. This review highlights these shared architectural elements and further examines specific nucleoporins. A particular emphasis is placed on the putative homologs yeast NUP1, human NUP153, and plant NUP136, and their shared involvement in critical processes such as developmental coordination, gene regulation, and immune responses. Despite variations in their amino acid sequences, these proteins exhibit a notable degree of structural conservation, supporting a convergent evolution that would underlie their similar functionalities. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
16. Unravelling the interaction between Influenza virus and the nuclear pore complex: insights into viral replication and host immune response
- Author
-
Khanna, Madhu, Sharma, Kajal, Saxena, Shailendra K., Sharma, Jai Gopal, Rajput, Roopali, and Kumar, Binod
- Published
- 2024
- Full Text
- View/download PDF
17. From the sideline: Tissue‐specific nucleoporin function in health and disease, an update.
- Author
-
Jühlen, Ramona and Fahrenkrog, Birthe
- Subjects
- *
NUCLEOTIDE sequencing , *NUCLEOCYTOPLASMIC interactions , *NUCLEAR transport (Cytology) , *CELL physiology , *NUCLEOPORINS - Abstract
The subcellular compartmentalisation of eukaryotic cells requires selective exchange between the cytoplasm and the nucleus. Intact nucleocytoplasmic transport is vital for normal cell function and mutations in the executing machinery have been causally linked to human disease. Central players in nucleocytoplasmic exchange are nuclear pore complexes (NPCs), which are built from ~30 distinct proteins collectively termed nucleoporins. Aberrant nucleoporin expression was detected in human cancers and autoimmune diseases since quite some time, while it was through the increasing use of next generation sequencing that mutations in nucleoporin genes associated with mainly rare hereditary diseases were revealed. The number of newly identified mutations is steadily increasing, as is the number of diseases. Mutational hotspots have emerged: mutations in the scaffold nucleoporins seemingly affect primarily inner organs, such as heart, kidney, and ovaries, whereas genetic alterations in peripheral, cytoplasmic nucleoporins affect primarily the central nervous system and development. In this review, we summarise latest insights on altered nucleoporin function in the context of human hereditary disorders, with a focus on those where mechanistic insights are beginning to emerge. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
18. Autophagy as a caretaker of nuclear integrity.
- Author
-
Boyle, Emily and Wilfling, Florian
- Subjects
- *
AUTOPHAGY , *NUCLEAR proteins , *NUCLEOPORINS , *HOMEOSTASIS , *CAENORHABDITIS elegans , *EUKARYOTES - Abstract
Due to their essential functions, dysregulation of nuclear pore complexes (NPCs) is strongly associated with numerous human diseases, including neurodegeneration and cancer. On a cellular level, longevity of scaffold nucleoporins in postmitotic cells of both C. elegans and mammals renders them vulnerable to age‐related damage, which is associated with an increase in pore leakiness and accumulation of intranuclear aggregates in rat brain cells. Thus, understanding the mechanisms which underpin the homeostasis of this complex, as well as other nuclear proteins, is essential. In this review, autophagy‐mediated degradation pathways governing nuclear components in yeast will be discussed, with a particular focus on NPCs. Furthermore, the various nuclear degradation mechanisms identified thus far in diverse eukaryotes will also be highlighted. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
19. Puzzling out nuclear pore complex assembly.
- Author
-
Penzo, Arianna and Palancade, Benoit
- Subjects
- *
NUCLEAR membranes , *NUCLEOPORINS , *CYTOPLASM - Abstract
Nuclear pore complexes (NPCs) are sophisticated multiprotein assemblies embedded within the nuclear envelope and controlling the exchanges of molecules between the cytoplasm and the nucleus. In this review, we summarize the mechanisms by which these elaborate complexes are built from their subunits, the nucleoporins, based on our ever‐growing knowledge of NPC structural organization and on the recent identification of additional features of this process. We present the constraints faced during the production of nucleoporins, their gathering into oligomeric complexes, and the formation of NPCs within nuclear envelopes, and review the cellular strategies at play, from co‐translational assembly to the enrolment of a panel of cofactors. Remarkably, the study of NPCs can inform our perception of the biogenesis of multiprotein complexes in general – and vice versa. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
20. Nuclear pore complex and nucleocytoplasmic transport disruption in neurodegeneration.
- Author
-
Cristi, América Chandía, Rapuri, Sampath, and Coyne, Alyssa N.
- Subjects
- *
NUCLEAR transport (Cytology) , *NUCLEOCYTOPLASMIC interactions , *NUCLEAR membranes , *NEURODEGENERATION , *GENETIC regulation , *NUCLEOPORINS - Abstract
Nuclear pore complexes (NPCs) play a critical role in maintaining the equilibrium between the nucleus and cytoplasm, enabling bidirectional transport across the nuclear envelope, and are essential for proper nuclear organization and gene regulation. Perturbations in the regulatory mechanisms governing NPCs and nuclear envelope homeostasis have been implicated in the pathogenesis of several neurodegenerative diseases. The ESCRT‐III pathway emerges as a critical player in the surveillance and preservation of well‐assembled, functional NPCs, as well as nuclear envelope sealing. Recent studies have provided insights into the involvement of nuclear ESCRT‐III in the selective reduction of specific nucleoporins associated with neurodegenerative pathologies. Thus, maintaining quality control of the nuclear envelope and NPCs represents a pivotal element in the pathological cascade leading to neurodegenerative diseases. This review describes the constituents of the nuclear‐cytoplasmic transport machinery, encompassing the nuclear envelope, NPC, and ESCRT proteins, and how their structural and functional alterations contribute to the development of neurodegenerative diseases. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
21. Coordinating nucleoporin condensation and nuclear pore complex assembly.
- Author
-
Kuiper, E. F. Elsiena, Prophet, Sarah M., and Schlieker, Christian
- Subjects
- *
AMYOTROPHIC lateral sclerosis , *CONDENSATION , *AQUAPORINS , *PROTEASOMES , *MOVEMENT disorders , *NUCLEOPORINS - Abstract
The nuclear pore complex (NPC) is among the most elaborate protein complexes in eukaryotes. While ribosomes and proteasomes are known to require dedicated assembly machinery, our understanding of NPC assembly is at a relatively early stage. Defects in NPC assembly or homeostasis are tied to movement disorders, including dystonia and amyotrophic lateral sclerosis (ALS), as well as aging, requiring a better understanding of these processes to enable therapeutic intervention. Here, we discuss recent progress in the understanding of NPC assembly and highlight how related defects in human disorders can shed light on NPC biogenesis. We propose that the condensation of phenylalanine‐glycine repeat nucleoporins needs to be carefully controlled during NPC assembly to prevent aberrant condensation, aggregation, or amyloid formation. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
22. Unusual Biomolecular Condensates Containing Nucleoporins or Lamin in the Germinal Vesicle of the Common Frog.
- Author
-
Bogolyubov, D. S. and Bogolyubova, I. O.
- Abstract
The nucleus (germinal vesicle, GV) of late vitellogenic oocytes of the European common frog, Rana temporaria, was found to contain biomolecular condensates (BioMCs) that accumulate nucleoporins Nup93, Nup 35, or a protein recognized by antibodies against lamin B. Apart, the studied nucleoporins are diffusely distributed throughout the GV and seem not present in peculiar structures, annuli, previously thought to represent nucleoplasmic autonomous pore complexes. Intranuclear membrane compartments (e.g., modified nuclear annulata lamellae), previously considered to represent derivatives of the nuclear envelope, did not show the presence of the studied nucleoporins and lamin. The molecular composition and functions of the extrachromosomal nuclear structures characteristic of R. temporaria oocytes, including the new type of BioMCs described here, remain unknown, highlighting the complexity of the internal organization of the GV. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
23. Caspase-mediated nuclear pore complex trimming in cell differentiation and endoplasmic reticulum stress.
- Author
-
Cho, Ukrae H. and Hetzer, Martin W.
- Subjects
- *
CELL differentiation , *ENDOPLASMIC reticulum , *MITOCHONDRIAL proteins , *CASPASES , *NUCLEOPORINS , *CELL physiology - Abstract
During apoptosis, caspases degrade 8 out of ~30 nucleoporins to irreversibly demolish the nuclear pore complex. However, for poorly understood reasons, caspases are also activated during cell differentiation. Here, we show that sublethal activation of caspases during myogenesis results in the transient proteolysis of four peripheral Nups and one transmembrane Nup. 'Trimmed' NPCs become nuclear export-defective, and we identified in an unbiased manner several classes of cytoplasmic, plasma membrane, and mitochondrial proteins that rapidly accumulate in the nucleus. NPC trimming by non-apoptotic caspases was also observed in neurogenesis and endoplasmic reticulum stress. Our results suggest that caspases can reversibly modulate nuclear transport activity, which allows them to function as agents of cell differentiation and adaptation at sublethal levels. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
24. Nucleoporin Nup358 Downregulation Tunes the Neuronal Excitability in Mouse Cortical Neurons.
- Author
-
Martínez-Rojas, Vladimir A., Pischedda, Francesca, Romero-Maldonado, Isabel, Khalaf, Bouchra, Piccoli, Giovanni, Macchi, Paolo, and Musio, Carlo
- Subjects
- *
NUCLEAR membranes , *SODIUM channels , *SCAFFOLD proteins , *NEURONS , *DOWNREGULATION , *NUCLEOPORINS , *MICE - Abstract
Nucleoporins (NUPs) are proteins that comprise the nuclear pore complexes (NPCs). The NPC spans the nuclear envelope of a cell and provides a channel through which RNA and proteins move between the nucleus and the cytoplasm and vice versa. NUP and NPC disruptions have a great impact on the pathophysiology of neurodegenerative diseases (NDDs). Although the downregulation of Nup358 leads to a reduction in the scaffold protein ankyrin-G at the axon initial segment (AIS) of mature neurons, the function of Nup358 in the cytoplasm of neurons remains elusive. To investigate whether Nup358 plays any role in neuronal activity, we downregulated Nup358 in non-pathological mouse cortical neurons and measured their active and passive bioelectrical properties. We identified that Nup358 downregulation is able to produce significant modifications of cell-membrane excitability via voltage-gated sodium channel kinetics. Our findings suggest that Nup358 contributes to neuronal excitability through a functional stabilization of the electrical properties of the neuronal membrane. Hypotheses will be discussed regarding the alteration of this active regulation as putatively occurring in the pathophysiology of NDDs. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
25. A-type lamins involvement in transport and implications in cancer?
- Author
-
Nicholas R. Scott and Sapun H. Parekh
- Subjects
A-type lamins ,cancer ,nuclear trafficking ,nucleus ,nucleoporins ,size dependent transport ,Genetics ,QH426-470 ,Cytology ,QH573-671 - Abstract
Nuclear lamins and transport are intrinsically linked, but their relationship is yet to be fully unraveled. A multitude of complex, coupled interactions between lamins and nucleoporins (Nups), which mediate active transport into and out of the nucleus, combined with well documented dysregulation of lamins in many cancers, suggests that lamins and nuclear transport may play a pivotal role in carcinogenesis and the preservation of cancer. Changes of function related to lamin/Nup activity can principally lead to DNA damage, further increasing the genetic diversity within a tumor, which could lead to the reduction the effectiveness of antineoplastic treatments. This review discusses and synthesizes different connections of lamins to nuclear transport and offers a number of outlook questions, the answers to which could reveal a new perspective on the connection of lamins to molecular transport of cancer therapeutics, in addition to their established role in nuclear mechanics.
- Published
- 2022
- Full Text
- View/download PDF
26. Trafficking and/or division: Distinct roles of nucleoporins based on their location within the nuclear pore complex
- Author
-
Eva Hegedűsová, Veronika Maršalová, Sneha Kulkarni, and Zdeněk Paris
- Subjects
trna trafficking ,nucleoporins ,nuclear division ,fg-nups ,npc ,trypanosoma brucei ,Genetics ,QH426-470 - Abstract
The nuclear pore complex (NPC) facilitates the trafficking of proteins and RNA between the nucleus and cytoplasm. The role of nucleoporins (Nups) in transport in the context of the NPC is well established, yet their function in tRNA export has not been fully explored. We selected several nucleoporins from different parts of the NPC to investigate their potential role in tRNA trafficking in Trypanosoma brucei. We show that while all of the nucleoporins studied are essential for cell viability, only TbNup62 and TbNup53a function in tRNA export. In contrast to homologs in yeast TbNup144 and TbNup158, which are part of the inner and outer ring of the NPC, have no role in nuclear tRNA trafficking. Instead, TbNup144 plays a critical role in nuclear division, highlighting the role of nucleoporins beyond nucleocytoplasmic transport. These results suggest that the location of nucleoporins within the NPC is crucial to maintaining various cellular processes.
- Published
- 2022
- Full Text
- View/download PDF
27. Assembly and Disassembly of the Nuclear Pore Complex: A View from the Structural Side.
- Author
-
Orlova, A. V., Georgieva, S. G., and Kopytova, D. V.
- Subjects
- *
NUCLEAR membranes , *MIRROR symmetry , *CELL cycle , *NUCLEOPORINS , *WAGE payment systems , *CYTOPLASM - Abstract
Abstract—Nucleocytoplasmic exchange in the cell occurs through the nuclear pore complexes (NPCs). NPCs are large multiprotein complexes with octagonal symmetry about their axis and imperfect mirror symmetry about a plane parallel with the nuclear envelop (NE). NPC fuses the inner and outer nuclear membranes and opens up a channel between nucleus and cytoplasm. NPC is built of nucleoporins. Each nucleoporin occurs in at least eight copies per NPC. Inside the NPC a permeability barrier forms by which NPCs can provide fast and selectable transport of molecules from one side of the nuclear membrane to the other. NPC architecture is based on hierarchical principle of organization. Nucleoporins are integrated into complexes that oligomerizes into bigger octomeric high-order structures. These structures are the main components of NPCs. In the first part of this work, the main attention is paid to NPC structure and nucleoporin properties. The second part is dedicated to mechanisms of NPC assembly and disassembly at different stages of the cell cycle. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
28. Non-classical functions of nuclear pore proteins in ciliopathy
- Author
-
Yan Chen, Yuan Zhang, and Xiangyu Zhou
- Subjects
nuclear pore proteins ,nucleoporins ,Nup205 ,Nup188 ,cilia ,ciliopathy ,Biology (General) ,QH301-705.5 - Abstract
Nucleoporins (NUPs) constitute integral nuclear pore protein (NPC) elements. Although traditional NUP functions have been extensively researched, evidence of additional vital non-NPC roles, referred to herein as non-classical NUP functions, is also emerging. Several NUPs localise at the ciliary base. Indeed, Nup188, Nup93 or Nup205 knockdown results in cilia loss, impacting cardiac left–right patterning in models and cell lines. Genetic variants of Nup205 and Nup188 have been identified in patients with congenital heart disease and situs inversus totalis or heterotaxy, a prevalent human ciliopathy. These findings link non-classical NUP functions to human diseases. This mini-review summarises pivotal NUP interactions with NIMA-related kinases or nephronophthisis proteins that regulate ciliary function and explores other NUPs potentially implicated in cilia-related disorders. Overall, elucidating the non-classical roles of NUPs will enhance comprehension of ciliopathy aetiology.
- Published
- 2023
- Full Text
- View/download PDF
29. Nucleoporin foci are stress‐sensitive condensates dispensable for C. elegans nuclear pore assembly.
- Author
-
Thomas, Laura, Taleb Ismail, Basma, Askjaer, Peter, and Seydoux, Geraldine
- Subjects
- *
CAENORHABDITIS elegans , *POST-translational modification , *SPERMATOZOA , *NUCLEOPORINS , *ANIMAL young , *OVUM - Abstract
Nucleoporins (Nups) assemble nuclear pores that form the permeability barrier between nucleoplasm and cytoplasm. Nucleoporins also localize in cytoplasmic foci proposed to function as pore pre‐assembly intermediates. Here, we characterize the composition and incidence of cytoplasmic Nup foci in an intact animal, C. elegans. We find that, in young non‐stressed animals, Nup foci only appear in developing sperm, oocytes and embryos, tissues that express high levels of nucleoporins. The foci are condensates of highly cohesive FG repeat‐containing nucleoporins (FG‐Nups), which are maintained near their solubility limit in the cytoplasm by posttranslational modifications and chaperone activity. Only a minor fraction of FG‐Nup molecules concentrate in Nup foci, which dissolve during M phase and are dispensable for nuclear pore assembly. Nucleoporin condensation is enhanced by stress and advancing age, and overexpression of a single FG‐Nup in post‐mitotic neurons is sufficient to induce ectopic condensation and organismal paralysis. We speculate that Nup foci are non‐essential and potentially toxic condensates whose assembly is actively suppressed in healthy cells. Synopsis: Highly cohesive, phenylalanine/glycine repeat‐containing nucleoporins (FG‐Nups) form the central channel of nuclear pores and also concentrate in cytoplasmic foci proposed to function as pore pre‐assembly intermediates. This study in the C. elegans model shows that nucleoporin (Nup) foci are transient condensates that are not essential for pore assembly. Cellular Nup foci arise when FG‐Nups accumulate at high levels in the cytoplasm exceeding their solubility limit, such as in oocytes and developing embryos.FG‐Nup solubility is enhanced by posttranslational modifications, including GlcNAcylation and phosphorylation, as well as by chaperone activity.FG‐Nup foci are transient structures that dissolve during M phase, when FG‐Nup solubility increases. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
30. Interaction of nucleoporins with nuclear transport receptors: a structural perspective.
- Author
-
Kehlenbach, Ralph H., Neumann, Piotr, Ficner, Ralf, and Dickmanns, Achim
- Subjects
- *
NUCLEOPORINS , *NUCLEAR transport (Cytology) , *NUCLEOCYTOPLASMIC interactions , *BINDING sites , *SURFACE area - Abstract
Soluble nuclear transport receptors and stationary nucleoporins are at the heart of the nucleocytoplasmic transport machinery. A subset of nucleoporins contains characteristic and repetitive FG (phenylalanine-glycine) motifs, which are the basis for the permeability barrier of the nuclear pore complex (NPC) that controls transport of macromolecules between the nucleus and the cytoplasm. FG-motifs can interact with each other and/or with transport receptors, mediating their translocation across the NPC. The molecular details of homotypic and heterotypic FG-interactions have been analyzed at the structural level. In this review, we focus on the interactions of nucleoporins with nuclear transport receptors. Besides the conventional FG-motifs as interaction spots, a thorough structural analysis led us to identify additional similar motifs at the binding interface between nucleoporins and transport receptors. A detailed analysis of all known human nucleoporins revealed a large number of such phenylalanine-containing motifs that are not buried in the predicted 3D-structure of the respective protein but constitute part of the solvent-accessible surface area. Only nucleoporins that are rich in conventional FG-repeats are also enriched for these motifs. This additional layer of potential low-affinity binding sites on nucleoporins for transport receptors may have a strong impact on the interaction of transport complexes with the nuclear pore and, thus, the efficiency of nucleocytoplasmic transport. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
31. The HIV-1 capsid core is an opportunistic nuclear import receptor.
- Author
-
Xue, Guangai, Yu, Hyun Jae, Buffone, Cindy, Huang, Szu-Wei, Lee, KyeongEun, Goh, Shih Lin, Gres, Anna T., Guney, Mehmet Hakan, Sarafianos, Stefan G., Luban, Jeremy, Diaz-Griffero, Felipe, and KewalRamani, Vineet N.
- Subjects
HIV ,NUCLEOPORINS - Abstract
The movement of viruses and other large macromolecular cargo through nuclear pore complexes (NPCs) is poorly understood. The human immunodeficiency virus type 1 (HIV-1) provides an attractive model to interrogate this process. HIV-1 capsid (CA), the chief structural component of the viral core, is a critical determinant in nuclear transport of the virus. HIV-1 interactions with NPCs are dependent on CA, which makes direct contact with nucleoporins (Nups). Here we identify Nup35, Nup153, and POM121 to coordinately support HIV-1 nuclear entry. For Nup35 and POM121, this dependence was dependent cyclophilin A (CypA) interaction with CA. Mutation of CA or removal of soluble host factors changed the interaction with the NPC. Nup35 and POM121 make direct interactions with HIV-1 CA via regions containing phenylalanine glycine motifs (FG-motifs). Collectively, these findings provide additional evidence that the HIV-1 CA core functions as a macromolecular nuclear transport receptor (NTR) that exploits soluble host factors to modulate NPC requirements during nuclear invasion. Nuclear import of the HIV-1 capsid (CA) is mediated through direct interactions with components of the nuclear pore complexes. Here, the authors identify Nup35 and POM121 as HIV-1 CA interacting factors regulating nuclear entry and further demonstrate regulation of the process by soluble factors Cyclophilin A and CPSF6. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
32. Distinct domains in Ndc1 mediate its interaction with the Nup84 complex and the nuclear membrane.
- Author
-
Amm, Ingo, Weberruss, Marion, Hellwig, Andrea, Schwarz, Johannes, Tatarek-Nossol, Marianna, Lüchtenborg, Christian, Kallas, Martina, Brügger, Britta, Hurt, Ed, and Antonin, Wolfram
- Subjects
- *
NUCLEAR membranes , *TRANSMEMBRANE domains , *NUCLEOPORINS , *MEMBRANE proteins , *LIPOSOMES , *BUILDING envelopes - Abstract
Nuclear pore complexes (NPCs) are embedded in the nuclear envelope and built from ~30 different nucleoporins (Nups) in multiple copies, few are integral membrane proteins. One of these transmembrane nucleoporins, Ndc1, is thought to function in NPC assembly at the fused inner and outer nuclear membranes. Here, we show a direct interaction of Ndc1's transmembrane domain with Nup120 and Nup133, members of the pore membrane coating Y-complex. We identify an amphipathic helix in Ndc1's C-terminal domain binding highly curved liposomes. Upon overexpression, this amphipathic motif is toxic and dramatically alters the intracellular membrane organization in yeast. Ndc1's amphipathic motif functionally interacts with related motifs in the C-terminus of the nucleoporins Nup53 and Nup59, important for pore membrane binding and interconnecting NPC modules. The essential function of Ndc1 can be suppressed by deleting the amphipathic helix from Nup53. Our data indicate that nuclear membrane and presumably NPC biogenesis depends on a balanced ratio between amphipathic motifs in diverse nucleoporins. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
33. Y-complex nucleoporins independently contribute to nuclear pore assembly and gene regulation in neuronal progenitors.
- Author
-
Orniacki, Clarisse, Verrico, Annalisa, Pelletier, Stéphane, Souquet, Benoit, Coulpier, Fanny, Jourdren, Laurent, Benetti, Serena, and Doye, Valérie
- Subjects
- *
GENETIC regulation , *NUCLEOPORINS , *NUCLEAR matrix , *GENE expression , *EMBRYONIC stem cells - Abstract
Besides assembling nuclear pore complexes, the conduits of nuclear transport, many nucleoporins also contribute to chromatin organization and gene expression, with critical roles in development and pathologies. We previously reported that Nup133 and Seh1, two components of the Y-complex subassembly of the nuclear pore scaffold, are dispensable for mouse embryonic stem cell viability but required for their survival during neuroectodermal differentiation. Here, a transcriptomic analysis revealed that Nup133 regulates a subset of genes at early stages of neuroectodermal differentiation, including Lhx1 and Nup210l, which encodes a newly validated nucleoporin. These genes are also misregulated in Nup133-Mid neuronal progenitors, in which nuclear pore basket assembly is impaired. However, a four-fold reduction of Nup133 levels, despite also affecting basket assembly, is not sufficient to alter Nup210l and Lhx1 expression. Finally, these two genes are also misregulated in Seh1-deficient neural progenitors, which only show amild reduction in nuclear pore density. Together these data reveal a shared function of Y-complex nucleoporins in gene regulation during neuroectodermal differentiation, apparently independent of nuclear pore basket integrity. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
34. Identification of New FG-Repeat Nucleoporins with Amyloid Properties.
- Author
-
Danilov, Lavrentii G., Sukhanova, Xenia V., Rogoza, Tatiana M., Antonova, Ekaterina Y., Trubitsina, Nina P., Zhouravleva, Galina A., and Bondarev, Stanislav A.
- Subjects
- *
NUCLEOPORINS , *AMYLOID beta-protein , *ZEBRA finch , *DROSOPHILA melanogaster , *SCHIZOSACCHAROMYCES pombe , *AMYLOID , *MICE - Abstract
Amyloids are fibrillar protein aggregates with a cross-β structure. More than two hundred different proteins with amyloid or amyloid-like properties are already known. Functional amyloids with conservative amyloidogenic regions were found in different organisms. Protein aggregation appears to be beneficial for the organism in these cases. Therefore, this property might be conservative for orthologous proteins. The amyloid aggregates of the CPEB protein were suggested to play an important role in the long-term memory formation in Aplysia californica, Drosophila melanogaster, and Mus musculus. Moreover, the FXR1 protein demonstrates amyloid properties among the Vertebrates. A few nucleoporins (e.g., yeast Nup49, Nup100, Nup116, and human Nup153 and Nup58), are supposed or proved to form amyloid fibrils. In this study, we performed wide-scale bioinformatic analysis of nucleoporins with FG-repeats (phenylalanine–glycine repeats). We demonstrated that most of the barrier nucleoporins possess potential amyloidogenic properties. Furthermore, the aggregation-prone properties of several Nsp1 and Nup100 orthologs in bacteria and yeast cells were analyzed. Only two new nucleoporins, Drosophila melanogaster Nup98 and Schizosaccharomyces pombe Nup98, aggregated in different experiments. At the same time, Taeniopygia guttata Nup58 only formed amyloids in bacterial cells. These results rather contradict the hypothesis about the functional aggregation of nucleoporins. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
35. Influenza virus mRNAs encode determinants for nuclear export via the cellular TREX-2 complex.
- Author
-
Bhat, Prasanna, Aksenova, Vasilisa, Gazzara, Matthew, Rex, Emily A., Aslam, Sadaf, Haddad, Christina, Gao, Shengyan, Esparza, Matthew, Cagatay, Tolga, Batten, Kimberly, El Zahed, Sara S., Arnaoutov, Alexei, Zhong, Hualin, Shay, Jerry W., Tolbert, Blanton S., Dasso, Mary, Lynch, Kristen W., García-Sastre, Adolfo, and Fontoura, Beatriz M. A.
- Subjects
INFLUENZA A virus ,INFLUENZA viruses ,NUCLEAR proteins ,NUCLEOPORINS ,INFLUENZA ,MESSENGER RNA ,NEURAMINIDASE - Abstract
Nuclear export of influenza A virus (IAV) mRNAs occurs through the nuclear pore complex (NPC). Using the Auxin-Induced Degron (AID) system to rapidly degrade proteins, we show that among the nucleoporins localized at the nucleoplasmic side of the NPC, TPR is the key nucleoporin required for nuclear export of influenza virus mRNAs. TPR recruits the TRanscription and EXport complex (TREX)−2 to the NPC for exporting a subset of cellular mRNAs. By degrading components of the TREX-2 complex (GANP, Germinal-center Associated Nuclear Protein; PCID2, PCI domain containing 2), we show that influenza mRNAs require the TREX-2 complex for nuclear export and replication. Furthermore, we found that cellular mRNAs whose export is dependent on GANP have a small number of exons, a high mean exon length, long 3' UTR, and low GC content. Some of these features are shared by influenza virus mRNAs. Additionally, we identified a 45 nucleotide RNA signal from influenza virus HA mRNA that is sufficient to mediate GANP-dependent mRNA export. Thus, we report a role for the TREX-2 complex in nuclear export of influenza mRNAs and identified RNA determinants associated with the TREX-2-dependent mRNA export. Here, Bhat et al. show that Influenza A virus mRNAs are exported from the nucleus via the nucleoporin Tpr and the mRNA export complex TREX-2. These mRNAs have low exon number, high mean exon length, and low GC content. A 45-nucleotide RNA signal can mediate export via TREX-2. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
36. Improving the hole picture: towards a consensus on the mechanism of nuclear transport.
- Author
-
Cowburn, David and Rout, Michael
- Subjects
- *
NUCLEOCYTOPLASMIC interactions , *NUCLEAR transport (Cytology) , *NUCLEIC acid separation , *VIRUS diseases , *NUCLEOPORINS - Abstract
Nuclear pore complexes (NPCs) mediate the exchange of materials between the nucleoplasm and cytoplasm, playing a key role in the separation of nucleic acids and proteins into their required compartments. The static structure of the NPC is relatively well defined by recent cryo-EM and other studies. The functional roles of dynamic components in the pore of the NPC, phenylalanyl-glycyl (FG) repeat rich nucleoporins, is less clear because of our limited understanding of highly dynamic protein systems. These proteins form a 'restrained concentrate' which interacts with and concentrates nuclear transport factors (NTRs) to provide facilitated nucleocytoplasmic transport of cargoes. Very rapid on- and off-rates among FG repeats and NTRs supports extremely fast facilitated transport, close to the rate of macromolecular diffusion in cytoplasm, while complexes without specific interactions are entropically excluded, though details on several aspects of the transport mechanism and FG repeat behaviors remain to be resolved. However, as discussed here, new technical approaches combined with more advanced modeling methods will likely provide an improved dynamic description of NPC transport, potentially at the atomic level in the near future. Such advances are likely to be of major benefit in comprehending the roles the malfunctioning NPC plays in cancer, ageing, viral diseases, and neurodegeneration. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
37. The capsid lattice engages a bipartite NUP153 motif to mediate nuclear entry of HIV-1 cores.
- Author
-
Qi Shen, Kumari, Sushila, Chaoyi Xu, Sooin Jang, Jiong Shi, Burdick, Ryan C., Levintov, Lev, Qiancheng Xiong, Chunxiang Wu, Devarkar, Swapnil C., Taoran Tian, Tripler, Therese N., Yingxia Hu, Shuai Yuan, Temple, Joshua, Qingzhou Feng, Lusk, C. Patrick, Aiken, Christopher, Engelman, Alan N., and Perilla, Juan R.
- Subjects
- *
HIV , *NUCLEOPORINS - Abstract
Increasing evidence has suggested that the HIV-1 capsid enters the nucleus in a largely assembled, intact form. However, not much is known about how the cone-shaped capsid interacts with the nucleoporins (NUPs) in the nuclear pore for crossing the nuclear pore complex. Here, we elucidate how NUP153 binds HIV-1 capsid by engaging the assembled capsid protein (CA) lattice. A bipartite motif containing both canonical and noncanonical interaction modules was identified at the C-terminal tail region of NUP153. The canonical cargo-targeting phenylalanine-glycine (FG) motif engaged the CA hexamer. By contrast, a previously unidentified triple-arginine (RRR) motif in NUP153 targeted HIV-1 capsid at the CA tri-hexamer interface in the capsid. HIV-1 infection studies indicated that both FG- and RRR-motifs were important for the nuclear import of HIV-1 cores. Moreover, the presence of NUP153 stabilized tubular CA assemblies in vitro. Our results provide molecular-level mechanistic evidence that NUP153 contributes to the entry of the intact capsid into the nucleus. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
38. Tau–FG-nucleoporin98 interaction and impaired nucleocytoplasmic transport in Alzheimer's disease.
- Author
-
Nag, Niharika and Tripathi, Timir
- Subjects
- *
NUCLEAR transport (Cytology) , *NUCLEOCYTOPLASMIC interactions , *ALZHEIMER'S disease , *TAU proteins , *NUCLEOPORINS - Abstract
An emerging pathophysiology associated with the neurodegenerative Alzheimer's disease (AD) is the impairment of nucleocytoplasmic transport (NCT). The impairment can originate from damage to the nuclear pore complex (NPC) or other factors involved in NCT. The phenylalanine-glycine nucleoporins (FG-Nups) form a crucial component of the NPC, which is central to NCT. Recent discoveries have highlighted that the neuropathological protein tau is involved in direct interactions with the FG-Nups and impairment of the NCT process. Targeting such interactions may lead to the identification of novel interaction inhibitors and offer new therapeutic alternatives for the treatment of AD. This review highlights recent findings associated with impaired NCT in AD and the interaction between tau and the FG-Nups. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
39. Nucleoplasmic Nup98 controls gene expression by regulating a DExH/D-box protein
- Author
-
Capitanio, Juliana S, Montpetit, Ben, and Wozniak, Richard W
- Subjects
Genetics ,Aetiology ,2.1 Biological and endogenous factors ,Cell Nucleus ,DEAD-box RNA Helicases ,Gene Expression Regulation ,Humans ,Nuclear Pore Complex Proteins ,RNA ,DDX3 ,DDX5 ,DDX21 ,DExD ,H-box helicases ,DHX9 ,FG-Nup ,gene expression regulation ,nuclear pore complex ,nucleoporins ,Nup98 ,DExD/H-box helicases - Abstract
The nucleoporin Nup98 has been linked to the regulation of transcription and RNA metabolism, 1-3 but the mechanisms by which Nup98 contributes to these processes remains largely undefined. Recently, we uncovered interactions between Nup98 and several DExH/D-box proteins (DBPs), a protein family well-known for modulating gene expression and RNA metabolism. 4-6 Analysis of Nup98 and one of these DBPs, DHX9, showed that they directly interact, their association is facilitated by RNA, and Nup98 binding stimulates DHX9 ATPase activity. 7 Furthermore, these proteins were dependent on one another for their proper association with a subset of gene loci to control transcription and modulate mRNA splicing. 7 On the basis of these observations, we proposed that Nup98 functions to regulate DHX9 activity within the nucleoplasm. 7 Since Nup98 is associated with several DBPs, regulation of DHX9 by Nup98 may represent a paradigm for understanding how Nup98, and possibly other FG-Nup proteins, could direct the diverse cellular activities of multiple DBPs.
- Published
- 2018
40. Effects of Sequence Composition, Patterning and Hydrodynamics on the Conformation and Dynamics of Intrinsically Disordered Proteins.
- Author
-
Vovk, Andrei and Zilman, Anton
- Subjects
- *
AMINO acid sequence , *HYDRODYNAMICS , *PROTEINS , *NUCLEOPORINS , *CELL physiology , *POLYMERS - Abstract
Intrinsically disordered proteins (IDPs) and intrinsically disordered regions (IDRs) perform diverse functions in cellular organization, transport and signaling. Unlike the well-defined structures of the classical natively folded proteins, IDPs and IDRs dynamically span large conformational and structural ensembles. This dynamic disorder impedes the study of the relationship between the amino acid sequences of the IDPs and their spatial structures and dynamics, with different experimental techniques often offering seemingly contradictory results. Although experimental and theoretical evidence indicates that some IDP properties can be understood based on their average biophysical properties and amino acid composition, other aspects of IDP function are dictated by the specifics of the amino acid sequence. We investigate the effects of several key variables on the dimensions and the dynamics of IDPs using coarse-grained polymer models. We focus on the sequence "patchiness" informed by the sequence and biophysical properties of different classes of IDPs—and in particular FG nucleoporins of the nuclear pore complex (NPC). We show that the sequence composition and patterning are well reflected in the global conformational variables such as the radius of gyration and hydrodynamic radius, while the end-to-end distance and dynamics are highly sequence-specific. We find that in good solvent conditions highly heterogeneous sequences of IDPs can be well mapped onto averaged minimal polymer models for the purpose of prediction of the IDPs dimensions and dynamic relaxation times. The coarse-grained simulations are in a good agreement with the results of atomistic MD. We discuss the implications of these results for the interpretation of the recent experimental measurements, and for the further applications of mesoscopic models of FG nucleoporins and IDPs more broadly. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
41. Identification of nuclear pore complexes (NPCs) and revealed outer-ring component BnHOS1 related to cold tolerance in B. napus.
- Author
-
Song, Min, Linghu, Bin, Huang, Shuhua, Hu, Shengwu, An, Ran, Wei, Shihao, Mu, Jianxin, and Zhang, Yanfeng
- Subjects
- *
GENE expression , *PROTEIN domains , *BIOMACROMOLECULES , *CRISPRS , *NUCLEOPORINS , *ISOMETRIC exercise - Abstract
Nuclear pore complexes (NPCs) consist of ~30 different nucleoporins (Nups), are the unique channels that govern development, hormonal response, and roles in both biotic and abiotic responses, as well as the transport and information exchange of biomacromolecules between nucleoplasms. Here, we report the comprehensive identification of 77 BnNups throughout the zhongshuang11 (ZS11) genome, which were classified into 29 distinct categories based on their evolutionary connections. We compared and contrasted different BnNups by analyzing at their gene structures, protein domains, putative three-dimensional (3D) models and expression patterns. Additional examples of genome-wide duplication events and cross-species synteny are provided to demonstrate the proliferation and evolutionary conservation of BnNups. When BnHOS1 was modified using CRISPR/Cas9 technology, the resulting L10 and L28 lines exhibited substantial freezing resistance. This not only demonstrated the negative regulatory impact of BnHOS1 on cold stress, but also offered a promising candidate gene for cold tolerance breeding and augmented the available B. napus material. These findings not only help us learn more about the composition and function of BnNPCs in B. napus , but they also provide light on how NPCs in other eukaryotic organism functions. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
42. Spelling out the roles of individual nucleoporins in nuclear export of mRNA.
- Author
-
Tingey, Mark, Li, Yichen, Yu, Wenlan, Young, Albert, and Yang, Weidong
- Subjects
- *
NUCLEOPORINS , *NUCLEAR membranes , *MESSENGER RNA , *NUCLEOCYTOPLASMIC interactions , *NUCLEAR transport (Cytology) - Abstract
The Nuclear Pore Complex (NPC) represents a critical passage through the nuclear envelope for nuclear import and export that impacts nearly every cellular process at some level. Recent technological advances in the form of Auxin Inducible Degron (AID) strategies and Single-Point Edge-Excitation sub-Diffraction (SPEED) microscopy have enabled us to provide new insight into the distinct functions and roles of nuclear basket nucleoporins (Nups) upon nuclear docking and export for mRNAs. In this paper, we provide a review of our recent findings as well as an assessment of new techniques, updated models, and future perspectives in the studies of mRNA's nuclear export. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
43. An introduction to dynamic nucleoporins in Leishmania species: Novel targets for tropical-therapeutics.
- Author
-
Dubey, Amit Kumar, Kumar, Prakash, Mandal, Debabrata, Ravichandiran, V., and Singh, Shubhankar Kumar
- Abstract
As an ailment, leishmaniasis is still an incessant challenge in neglected tropical diseases and neglected infections of poverty worldwide. At present, the diagnosis and treatment to combat Leishmania tropical infections are not substantial remedies and require advanced & specific research. Therefore, there is a need for a potential novel target to overcome established medicament modalities' limitations in pathogenicity. In this review, we proposed a few ab initio findings in nucleoporins of nuclear pore complex in Leishmania sp. concerning other infectious protists. So, through structural analysis and dynamics studies, we hypothesize the nuclear pore molecular machinery & functionality. The gatekeepers Nups, export of mRNA, mitotic spindle formation are salient features in cellular mechanics and this is regulated by dynamic nucleoporins. Here, diverse studies suggest that Nup93/NIC96, Nup155/Nup144, Mlp1/Mlp2/Tpr of Leishmania Species can be a picked out marker for diagnostic, immune-modulation, and novel drug targets. In silico prediction of nucleoporin-functional interactors such as NUP54/57, RNA helicase, Ubiquitin-protein ligase, Exportin 1, putative T-lymphocyte triggering factor, and 9 uncharacterized proteins suggest few more noble targets. The novel drug targeting to importins/exportins of Leishmania sp. and defining mechanism of Leptomycin-B, SINE compounds, Curcumins, Selinexor can be an arc-light in therapeutics. The essence of the review in Leishmania's nucleoporins is to refocus our research on noble molecular targets for tropical therapeutics. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
44. A-type lamins involvement in transport and implications in cancer?
- Author
-
Scott, Nicholas R. and Parekh, Sapun H.
- Subjects
LAMINS ,BIOLOGICAL transport ,NUCLEOPORINS ,DNA damage ,GENETIC variation - Abstract
Nuclear lamins and transport are intrinsically linked, but their relationship is yet to be fully unraveled. A multitude of complex, coupled interactions between lamins and nucleoporins (Nups), which mediate active transport into and out of the nucleus, combined with well documented dysregulation of lamins in many cancers, suggests that lamins and nuclear transport may play a pivotal role in carcinogenesis and the preservation of cancer. Changes of function related to lamin/Nup activity can principally lead to DNA damage, further increasing the genetic diversity within a tumor, which could lead to the reduction the effectiveness of antineoplastic treatments. This review discusses and synthesizes different connections of lamins to nuclear transport and offers a number of outlook questions, the answers to which could reveal a new perspective on the connection of lamins to molecular transport of cancer therapeutics, in addition to their established role in nuclear mechanics. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
45. Nup107 contributes to the maternal to zygotic transition by preventing the premature nuclear export of pri-miRNA 427.
- Author
-
Kostiuk V, Kabir R, Levangie K, Empke S, Morgan K, Owens NDL, Lusk CP, and Khokha MK
- Abstract
Emerging evidence suggests that the nuclear pore complex can have unique compositions and distinct nucleoporin functions in different cells. Here, we show that Nup107, a key component of the NPC scaffold, varies in expression over development: it is expressed at higher levels in the blastula compared to the gastrula suggesting a critical role prior to gastrulation. We find depletion of Nup107 affects the differentiation of the early germ layers leading to an expansion of the ectoderm at the expense of endoderm and mesoderm. By analyzing an RNAseq time course, we observed that depletion of Nup107 affects the maternal-zygotic transition by delaying the degradation of maternal transcripts that occurs as zygotic transcription begins. The transcripts are enriched in miR427 recognition sites, a conserved microRNA that destabilizes maternal transcripts including REST, which encodes a Kruppel-type zinc finger transcription factor that we demonstrate is critical for ectodermal cell fates. Mechanistically, we show that Nup107 is required to prevent the premature export of pri-miR427 transcript before processing. Nup107 depletion leads to the reduced production of mature miR427 and maternal transcript stabilization. We conclude that high levels of Nup107 in the early embryo are critical for the nuclear retention and subsequent processing of pri-miR427 transcripts that is required for timely maternal RNA clearance to enable gastrulation., (© 2025. Published by The Company of Biologists.)
- Published
- 2025
- Full Text
- View/download PDF
46. PRLX-93936 and BMS-214662 are cytotoxic molecular glues that leverage TRIM21 to degrade nucleoporins.
- Subjects
SMALL molecules ,PROTEOLYSIS ,CYTOTOXINS ,NUCLEOPORINS ,GLUE - Abstract
The article discusses the discovery of two cytotoxic molecular glues, PRLX-93936 and BMS-214662, which target the E3 ubiquitin ligase TRIM21 to degrade nucleoporin proteins, inhibiting nuclear export and leading to cell death. These molecules show potential for clinical re-evaluation in patients with TRIM21-high cancers and offer new opportunities for targeted protein degradation. The research is based on a phenotypic screening approach and has not yet been peer-reviewed. For more information, the full text can be found at biorxiv.org/content/10.1101/2024.12.18.629219v1. [Extracted from the article]
- Published
- 2025
47. Non-transport roles of nuclear import receptors: In need of the right balance
- Author
-
Michela Damizia, Ludovica Altieri, and Patrizia Lavia
- Subjects
nuclear transport ,importin beta family ,mitotic spindle ,nucleoporins ,ubiquitin/proteasome system ,protein aggregates ,Biology (General) ,QH301-705.5 - Abstract
Nuclear import receptors ensure the recognition and transport of proteins across the nuclear envelope into the nucleus. In addition, as diverse processes as mitosis, post-translational modifications at mitotic exit, ciliogenesis, and phase separation, all share a common need for regulation by nuclear import receptors - particularly importin beta-1 and importin beta-2/transportin - independent on nuclear import. In particular, 1) nuclear import receptors regulate the mitotic spindle after nuclear envelope breakdown, 2) they shield cargoes from unscheduled ubiquitination, regulating their timely proteolysis; 3) they regulate ciliary factors, crucial to cell communications and tissue architecture during development; and 4) they prevent phase separation of toxic proteins aggregates in neurons. The balance of nuclear import receptors to cargoes is critical in all these processes, albeit in opposite directions: overexpression of import receptors, as often found in cancer, inhibits cargoes and impairs downstream processes, motivating the therapeutic design of specific inhibitors. On the contrary, elevated expression is beneficial in neuronal contexts, where nuclear import receptors are regarded as potential therapeutic tools in counteracting the formation of aggregates that may cause neurodegeneration. This paradox demonstrates the amplitude of nuclear import receptors-dependent functions in different contexts and adds complexity in considering their therapeutic implications.
- Published
- 2022
- Full Text
- View/download PDF
48. The ESCRT-III protein VPS4, but not CHMP4B or CHMP2B, is pathologically increased in familial and sporadic ALS neuronal nuclei
- Author
-
Alyssa N. Coyne and Jeffrey D. Rothstein
- Subjects
Nucleoporins ,POM121 ,Nuclear pore complex ,ALS ,FTD ,CHMP7 ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Abstract Nuclear pore complex injury has recently emerged as an early and significant contributor to familial and sporadic ALS disease pathogenesis. However, the molecular events leading to this pathological phenomenon characterized by the reduction of specific nucleoporins from neuronal nuclear pore complexes remain largely unknown. This is due in part to a lack of knowledge regarding the biological pathways and proteins underlying nuclear pore complex homeostasis specifically in human neurons. We have recently uncovered that aberrant nuclear accumulation of the ESCRT-III protein CHMP7 initiates nuclear pore complex in familial and sporadic ALS neurons. In yeast and non-neuronal mammalian cells, nuclear relocalization of CHMP7 has been shown to recruit the ESCRT-III proteins CHMP4B, CHMP2B, and VPS4 to facilitate nuclear pore complex and nuclear envelope repair and homeostasis. Here, using super resolution structured illumination microscopy, we find that neither CHMP4B nor CHMP2B are increased in ALS neuronal nuclei. In contrast, VPS4 expression is significantly increased in ALS neuronal nuclei prior to the emergence of nuclear pore injury in a CHMP7 dependent manner. However, unlike our prior CHMP7 knockdown studies, impaired VPS4 function does not mitigate alterations to the NPC and the integral transmembrane nucleoporin POM121. Collectively our data suggest that while alterations in VPS4 subcellular localization appear to be coincident with nuclear pore complex injury, therapeutic efforts to mitigate this pathogenic cascade should be targeted towards upstream events such as the nuclear accumulation of CHMP7 as we have previously described.
- Published
- 2021
- Full Text
- View/download PDF
49. Efficacy and safety of patiromer for non-dialysis and dialysis patients with hyperkalemia: the randomized, placebo-controlled and long-term study.
- Author
-
Kashihara, Naoki, Kumeda, Yasuro, Higashino, Yorihiko, Maeda, Yoshitaka, Kaneko, Yoko, Kanai, Hidetoshi, Taniguchi, Yuko, Ishii, Takayuki, and Tomioka, Yusuke
- Subjects
- *
JAPANESE people , *NUCLEOPORINS , *HEMODIALYSIS patients , *LEAST squares , *ALGORITHMS - Abstract
Background: The objectives of this phase two study are to investigate the efficacy of two starting doses of 8.4 g and 16.8 g and evaluate the long-term safety of patiromer in Japanese patients with hyperkalemia.This study comprised three cohorts; non-dialysis patients with baseline serum potassium (sK) level of 5.1 to < 6.0 mmol/L (NDC1); 6.0 to < 6.5 mmol/L (NDC2); dialysis patients with baseline sK level of 5.5 to < 6.5 mmol/L (DC). The study design was one-week, randomized, double-blind, placebo-controlled, and open label extension for one year in NDC1, open label during the study in NDC2 and DC. Patients were randomly assigned to patiromer 8.4 g, 16.8 g or placebo in NDC1, 8.4 g or 16.8 g in NDC2 and DC. Dose was adjusted up to 25.2 g according to the titration algorism in open label period.A total of 185 patients were randomized (NDC1:153, NDC2:10, and DC:22). The primary endpoint of the change in least squares mean sK levels at Week 1 in NDC1 was – 0.55, – 0.77 and – 0.10 mmol/L for the 8.4 g, 16.8 g and placebo group (
P < 0.001 for the patiromer group vs the placebo group). In all cohorts for each patiromer group, more than 80% of patients achieved normal sK at Week 5. There was no severe treatment-related adverse event.Treatment with patiromer was effective in lowering and maintaining target sK levels, also well tolerated for one year in Japanese patients with hyperkalemia.Methods: The objectives of this phase two study are to investigate the efficacy of two starting doses of 8.4 g and 16.8 g and evaluate the long-term safety of patiromer in Japanese patients with hyperkalemia.This study comprised three cohorts; non-dialysis patients with baseline serum potassium (sK) level of 5.1 to < 6.0 mmol/L (NDC1); 6.0 to < 6.5 mmol/L (NDC2); dialysis patients with baseline sK level of 5.5 to < 6.5 mmol/L (DC). The study design was one-week, randomized, double-blind, placebo-controlled, and open label extension for one year in NDC1, open label during the study in NDC2 and DC. Patients were randomly assigned to patiromer 8.4 g, 16.8 g or placebo in NDC1, 8.4 g or 16.8 g in NDC2 and DC. Dose was adjusted up to 25.2 g according to the titration algorism in open label period.A total of 185 patients were randomized (NDC1:153, NDC2:10, and DC:22). The primary endpoint of the change in least squares mean sK levels at Week 1 in NDC1 was – 0.55, – 0.77 and – 0.10 mmol/L for the 8.4 g, 16.8 g and placebo group (P < 0.001 for the patiromer group vs the placebo group). In all cohorts for each patiromer group, more than 80% of patients achieved normal sK at Week 5. There was no severe treatment-related adverse event.Treatment with patiromer was effective in lowering and maintaining target sK levels, also well tolerated for one year in Japanese patients with hyperkalemia.Results: The objectives of this phase two study are to investigate the efficacy of two starting doses of 8.4 g and 16.8 g and evaluate the long-term safety of patiromer in Japanese patients with hyperkalemia.This study comprised three cohorts; non-dialysis patients with baseline serum potassium (sK) level of 5.1 to < 6.0 mmol/L (NDC1); 6.0 to < 6.5 mmol/L (NDC2); dialysis patients with baseline sK level of 5.5 to < 6.5 mmol/L (DC). The study design was one-week, randomized, double-blind, placebo-controlled, and open label extension for one year in NDC1, open label during the study in NDC2 and DC. Patients were randomly assigned to patiromer 8.4 g, 16.8 g or placebo in NDC1, 8.4 g or 16.8 g in NDC2 and DC. Dose was adjusted up to 25.2 g according to the titration algorism in open label period.A total of 185 patients were randomized (NDC1:153, NDC2:10, and DC:22). The primary endpoint of the change in least squares mean sK levels at Week 1 in NDC1 was – 0.55, – 0.77 and – 0.10 mmol/L for the 8.4 g, 16.8 g and placebo group (P < 0.001 for the patiromer group vs the placebo group). In all cohorts for each patiromer group, more than 80% of patients achieved normal sK at Week 5. There was no severe treatment-related adverse event.Treatment with patiromer was effective in lowering and maintaining target sK levels, also well tolerated for one year in Japanese patients with hyperkalemia.Conclusion: The objectives of this phase two study are to investigate the efficacy of two starting doses of 8.4 g and 16.8 g and evaluate the long-term safety of patiromer in Japanese patients with hyperkalemia.This study comprised three cohorts; non-dialysis patients with baseline serum potassium (sK) level of 5.1 to < 6.0 mmol/L (NDC1); 6.0 to < 6.5 mmol/L (NDC2); dialysis patients with baseline sK level of 5.5 to < 6.5 mmol/L (DC). The study design was one-week, randomized, double-blind, placebo-controlled, and open label extension for one year in NDC1, open label during the study in NDC2 and DC. Patients were randomly assigned to patiromer 8.4 g, 16.8 g or placebo in NDC1, 8.4 g or 16.8 g in NDC2 and DC. Dose was adjusted up to 25.2 g according to the titration algorism in open label period.A total of 185 patients were randomized (NDC1:153, NDC2:10, and DC:22). The primary endpoint of the change in least squares mean sK levels at Week 1 in NDC1 was – 0.55, – 0.77 and – 0.10 mmol/L for the 8.4 g, 16.8 g and placebo group (P < 0.001 for the patiromer group vs the placebo group). In all cohorts for each patiromer group, more than 80% of patients achieved normal sK at Week 5. There was no severe treatment-related adverse event.Treatment with patiromer was effective in lowering and maintaining target sK levels, also well tolerated for one year in Japanese patients with hyperkalemia. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
50. The molecular architecture of the nuclear basket.
- Author
-
Singh, Digvijay, Soni, Neelesh, Hutchings, Joshua, Echeverria, Ignacia, Shaikh, Farhaz, Duquette, Madeleine, Suslov, Sergey, Li, Zhixun, van Eeuwen, Trevor, Molloy, Kelly, Shi, Yi, Wang, Junjie, Guo, Qiang, Chait, Brian T., Fernandez-Martinez, Javier, Rout, Michael P., Sali, Andrej, and Villa, Elizabeth
- Subjects
- *
NUCLEAR pore complex , *NUCLEAR transport (Cytology) , *NUCLEOCYTOPLASMIC interactions , *PROTEIN domains , *NUCLEOPORINS - Abstract
The nuclear pore complex (NPC) is the sole mediator of nucleocytoplasmic transport. Despite great advances in understanding its conserved core architecture, the peripheral regions can exhibit considerable variation within and between species. One such structure is the cage-like nuclear basket. Despite its crucial roles in mRNA surveillance and chromatin organization, an architectural understanding has remained elusive. Using in-cell cryo-electron tomography and subtomogram analysis, we explored the NPC's structural variations and the nuclear basket across fungi (yeast; S. cerevisiae), mammals (mouse; M. musculus), and protozoa (T. gondii). Using integrative structural modeling, we computed a model of the basket in yeast and mammals that revealed how a hub of nucleoporins (Nups) in the nuclear ring binds to basket-forming Mlp/Tpr proteins: the coiled-coil domains of Mlp/Tpr form the struts of the basket, while their unstructured termini constitute the basket distal densities, which potentially serve as a docking site for mRNA preprocessing before nucleocytoplasmic transport. [Display omitted] • A stable basket is anchored by a hub of Nups into a double nuclear ring • Mlps/Tprs form struts; their N/C termini form a distal density that docks mRNA • A 20-nm exclusion zone around the basket suggests its role in chromatin organization • The stoichiometry of the outer rings is variable across and within species The elusive architecture of the nuclear basket reveals that a double ring is necessary to stabilize a hub of Nups from which the struts emanate. The basket's distal density contains the N/C termini of the strut-forming proteins that serve as a docking platform for cargo and nuclear periphery elements. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.