17 results on '"Seinstra RI"'
Search Results
2. Discovery and functional prioritization of Parkinson's disease candidate genes from large-scale whole exome sequencing
- Author
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Jansen, IE, Ye, H, Heetveld, S, Lechler, MC, Michels, H, Seinstra, RI, Lubbe, SJ, Drouet, V, Lesage, S, Majounie, E, Gibbs, JR, Nalls, MA, Ryten, M, Botia, JA, Vandrovcova, J, Simon-Sanchez, J, Castillo-Lizardo, M, Rizzu, P, Blauwendraat, C, Chouhan, AK, Li, Y, Yogi, P, Amin, N, van Duijn, CM, Morris, HR, Brice, A, Singleton, AB, David, DC, Nollen, EA, Jain, S, Shulman, JM, Heutink, P, Hernandez, DG, Arepalli, S, Brooks, J, Price, R, Nicolas, A, Chong, S, Cookson, MR, Dillman, A, Moore, M, Traynor, BJ, Plagnol, V, Nicholas, WW, Sheerin, UM, Jose, MB, Charlesworth, G, Gardner, M, Guerreiro, R, Trabzuni, D, Hardy, J, Sharma, M, Saad, M, Javier, S-S, Schulte, C, Corvol, JC, Dürr, A, Vidailhet, M, Sveinbjörnsdóttir, S, Barker, R, Caroline, HW-G, Ben-Shlomo, Y, Berendse, HW, van Dijk, KD, Berg, D, Brockmann, K, Wurster, I, Mätzler, W, Gasser, T, Martinez, M, de Bie, RMA, Biffi, A, and Velseboer, D
- Abstract
Background: Whole-exome sequencing (WES) has been successful in identifying genes that cause familial Parkinson's disease (PD). However, until now this approach has not been deployed to study large cohorts of unrelated participants. To discover rare PD susceptibility variants, we performed WES in 1148 unrelated cases and 503 control participants. Candidate genes were subsequently validated for functions relevant to PD based on parallel RNA-interference (RNAi) screens in human cell culture and Drosophila and C. elegans models. Results: Assuming autosomal recessive inheritance, we identify 27 genes that have homozygous or compound heterozygous loss-of-function variants in PD cases. Definitive replication and confirmation of these findings were hindered by potential heterogeneity and by the rarity of the implicated alleles. We therefore looked for potential genetic interactions with established PD mechanisms. Following RNAi-mediated knockdown, 15 of the genes modulated mitochondrial dynamics in human neuronal cultures and four candidates enhanced α-synuclein-induced neurodegeneration in Drosophila. Based on complementary analyses in independent human datasets, five functionally validated genes-GPATCH2L, UHRF1BP1L, PTPRH, ARSB, and VPS13C-also showed evidence consistent with genetic replication. Conclusions: By integrating human genetic and functional evidence, we identify several PD susceptibility gene candidates for further investigation. Our approach highlights a powerful experimental strategy with broad applicability for future studies of disorders with complex genetic etiologies.
- Published
- 2017
3. Delaying aging and the aging-associated decline in protein homeostasis by inhibition of tryptophan degradation
- Author
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van der Goot AT, Zhu W, Vázquez-Manrique RP, Seinstra RI, Dettmer K, Michels H, Farina F, Krijnen J, Melki R, Buijsman RC, Ruiz Silva M, Thijssen KL, Kema IP, Neri C, Oefner PJ, and Nollen EA
- Abstract
Toxicity of aggregation-prone proteins is thought to play an important role in aging and age-related neurological diseases like Parkinson and Alzheimer's diseases. Here, we identify tryptophan 2,3-dioxygenase (tdo-2), the first enzyme in the kynurenine pathway of tryptophan degradation, as a metabolic regulator of age-related a-synuclein toxicity in a Caenorhabditis elegans model. Depletion of tdo-2 also suppresses toxicity of other heterologous aggregation-prone proteins, including amyloid-ß and polyglutamine proteins, and endogenous metastable proteins that are sensors of normal protein homeostasis. This finding suggests that tdo-2 functions as a general regulator of protein homeostasis. Analysis of metabolite levels in C. elegans strains with mutations in enzymes that act downstream of tdo-2 indicates that this suppression of toxicity is independent of downstream metabolites in the kynurenine pathway. Depletion of tdo-2 increases tryptophan levels, and feeding worms with extra L-tryptophan also suppresses toxicity, suggesting that tdo-2 regulates proteotoxicity through tryptophan. Depletion of tdo-2 extends lifespan in these worms. Together, these results implicate tdo-2 as a metabolic switch of age-related protein homeostasis and lifespan. With TDO and Indoleamine 2,3-dioxygenase as evolutionarily conserved human orthologs of TDO-2, intervening with tryptophan metabolism may offer avenues to reducing proteotoxicity in aging and age-related diseases.
- Published
- 2012
4. Rebalancing the motor circuit restores movement in a Caenorhabditis elegans model for TDP-43 toxicity.
- Author
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Koopman M, Güngördü L, Janssen L, Seinstra RI, Richmond JE, Okerlund N, Wardenaar R, Islam P, Hogewerf W, Brown AEX, Jorgensen EM, and Nollen EAA
- Subjects
- Animals, Caenorhabditis elegans Proteins metabolism, Caenorhabditis elegans Proteins genetics, Cholinergic Neurons metabolism, GABAergic Neurons metabolism, Locomotion, Motor Neurons metabolism, Movement, Synaptic Transmission, Caenorhabditis elegans metabolism, Disease Models, Animal, DNA-Binding Proteins metabolism, DNA-Binding Proteins genetics, TDP-43 Proteinopathies genetics, TDP-43 Proteinopathies metabolism
- Abstract
Amyotrophic lateral sclerosis can be caused by abnormal accumulation of TAR DNA-binding protein 43 (TDP-43) in the cytoplasm of neurons. Here, we use a C. elegans model for TDP-43-induced toxicity to identify the biological mechanisms that lead to disease-related phenotypes. By applying deep behavioral phenotyping and subsequent dissection of the neuromuscular circuit, we show that TDP-43 worms have profound defects in GABA neurons. Moreover, acetylcholine neurons appear functionally silenced. Enhancing functional output of repressed acetylcholine neurons at the level of, among others, G-protein-coupled receptors restores neurotransmission, but inefficiently rescues locomotion. Rebalancing the excitatory-to-inhibitory ratio in the neuromuscular system by simultaneous stimulation of the affected GABA- and acetylcholine neurons, however, not only synergizes the effects of boosting individual neurotransmitter systems, but instantaneously improves movement. Our results suggest that interventions accounting for the altered connectome may be more efficient in restoring motor function than those solely focusing on diseased neuron populations., Competing Interests: Declaration of interests L.J. is currently employed by AstraZeneca as a medical advisor and M.K. is employed by the health insurance company Zilveren Kruis as a data scientist; both positions are unrelated to the current article., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2024
- Full Text
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5. Neuronal overexpression of hTDP-43 in Caenorhabditis elegans mimics the cellular pathology commonly observed in TDP-43 proteinopathies.
- Author
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Koopman M, Güngördü L, Seinstra RI, Hogewerf W, and Nollen EAA
- Abstract
Inclusions consisting of transactive response DNA-binding protein 43 (TDP-43) are a characteristic feature of amyotrophic lateral sclerosis (ALS). Caenorhabditis elegans has been instrumental in studying the underlying mechanisms of TDP-43 pathology. Here, we extend the possibilities of previous studies by examining a C. elegans model expressing human wild-type TDP-43 ( hTDP-43 ) pan-neuronally. We show that disease-related (hyper)phosphorylation and cytosolic localisation of hTDP-43 are present in hTDP-43 worms and that these features can be enhanced by adjusting the environmental temperature., Competing Interests: The authors declare that there are no conflicts of interest present., (Copyright: © 2023 by the authors.)
- Published
- 2023
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6. Neuronal overexpression of hTDP-43 in Caenorhabditis elegans impairs different neuronally controlled behaviors and decreases fecundity.
- Author
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Koopman M, Güngördü L, Seinstra RI, and Nollen EAA
- Abstract
Cytoplasmic inclusions consisting of transactive response DNA-binding protein 43 (TDP-43) are a key hallmark of TDP-43 proteinopathies like amyotrophic lateral sclerosis (ALS). Caenorhabditis elegans is considered a useful model for studying the molecular mechanisms underlying TDP-43 toxicity in vivo . Here, we assessed different neuronal systems through established behavioral assays and extended the phenotypic characterisation of a C. elegans model expressing wildtype human TDP-43 ( hTDP-43 ) pan-neuronally. Our data show that neuronal expression of hTDP-43 in C. elegans disrupts chemotaxis and decreases fecundity. The basal slowing response, on the other hand, appears to be preserved in the presence of hTDP-43., Competing Interests: The authors declare that there are no conflicts of interest present., (Copyright: © 2023 by the authors.)
- Published
- 2023
- Full Text
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7. Neuronal overexpression of human TDP-43 in Caenorhabditis elegans causes a range of sensorimotor phenotypes.
- Author
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Koopman M, Güngördü L, Seinstra RI, and Nollen EAA
- Abstract
Competing Interests: The authors declare that there are no conflicts of interest present.
- Published
- 2023
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8. Neuronal overexpression of hTDP-43 in Caenorhabditis elegans impairs motor function.
- Author
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Koopman M, Güngördü L, Seinstra RI, and Nollen EAA
- Abstract
Transactive response DNA binding-protein 43 (TDP-43) is a conserved RNA/DNA-binding protein with a role in RNA metabolism and homeostasis. Aberrant TDP-43 functioning has been considered a major culprit in amyotrophic lateral sclerosis (ALS). Caenorhabditis elegans can be used to phenocopy ALS in vivo . Since disrupted locomotion is a strong readout of toxicity, we examined multiple motor phenotypes of a C. elegans model expressing human wild-type TDP-43 ( hTDP-43 ) pan-neuronally. Our data reveal that impaired locomotion includes more than the common deficits in crawling capacity and the presence of early-onset paralysis. We show that reduced thrashing, abnormal coiling, and decreased pharyngeal pumping are also observed, in a temperature-dependent fashion., Competing Interests: The authors declare that there are no conflicts of interest present., (Copyright: © 2023 by the authors.)
- Published
- 2023
- Full Text
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9. Assessing motor-related phenotypes of Caenorhabditis elegans with the wide field-of-view nematode tracking platform.
- Author
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Koopman M, Peter Q, Seinstra RI, Perni M, Vendruscolo M, Dobson CM, Knowles TPJ, and Nollen EAA
- Subjects
- Animals, Biological Assay instrumentation, Caenorhabditis elegans physiology, Movement, Phenotype
- Abstract
Caenorhabditis elegans is a valuable model organism in biomedical research that has led to major discoveries in the fields of neurodegeneration, cancer and aging. Because movement phenotypes are commonly used and represent strong indicators of C. elegans fitness, there is an increasing need to replace manual assessments of worm motility with automated measurements to increase throughput and minimize observer biases. Here, we provide a protocol for the implementation of the improved wide field-of-view nematode tracking platform (WF-NTP), which enables the simultaneous analysis of hundreds of worms with respect to multiple behavioral parameters. The protocol takes only a few hours to complete, excluding the time spent culturing C. elegans, and includes (i) experimental design and preparation of samples, (ii) data recording, (iii) software management with appropriate parameter choices and (iv) post-experimental data analysis. We compare the WF-NTP with other existing worm trackers, including those having high spatial resolution. The main benefits of WF-NTP relate to the high number of worms that can be assessed at the same time on a whole-plate basis and the number of phenotypes that can be screened for simultaneously.
- Published
- 2020
- Full Text
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10. Transcriptomics-Based Screening Identifies Pharmacological Inhibition of Hsp90 as a Means to Defer Aging.
- Author
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Janssens GE, Lin XX, Millan-Ariño L, Kavšek A, Sen I, Seinstra RI, Stroustrup N, Nollen EAA, and Riedel CG
- Subjects
- Aging genetics, Animals, Caenorhabditis elegans drug effects, Caenorhabditis elegans genetics, Caenorhabditis elegans Proteins antagonists & inhibitors, Caenorhabditis elegans Proteins metabolism, HSP90 Heat-Shock Proteins metabolism, Heat Shock Transcription Factors metabolism, Signal Transduction drug effects, Transcription Factors antagonists & inhibitors, Transcription Factors metabolism, Transcriptome, Aging drug effects, Benzoquinones pharmacology, HSP90 Heat-Shock Proteins antagonists & inhibitors, Lactams, Macrocyclic pharmacology, Macrolides pharmacology
- Abstract
Aging strongly influences human morbidity and mortality. Thus, aging-preventive compounds could greatly improve our health and lifespan. Here we screened for such compounds, known as geroprotectors, employing the power of transcriptomics to predict biological age. Using age-stratified human tissue transcriptomes and machine learning, we generated age classifiers and applied these to transcriptomic changes induced by 1,309 different compounds in human cells, ranking these compounds by their ability to induce a "youthful" transcriptional state. Testing the top candidates in C. elegans, we identified two Hsp90 inhibitors, monorden and tanespimycin, which extended the animals' lifespan and improved their health. Hsp90 inhibition induces expression of heat shock proteins known to improve protein homeostasis. Consistently, monorden treatment improved the survival of C. elegans under proteotoxic stress, and its benefits depended on the cytosolic unfolded protein response-inducing transcription factor HSF-1. Taken together, our method represents an innovative geroprotector screening approach and was able to identify a class that acts by improving protein homeostasis., (Copyright © 2019 The Author(s). Published by Elsevier Inc. All rights reserved.)
- Published
- 2019
- Full Text
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11. C. elegans as a Model for Synucleinopathies and Other Neurodegenerative Diseases: Tools and Techniques.
- Author
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Koopman M, Seinstra RI, and Nollen EAA
- Subjects
- Animals, Caenorhabditis elegans, Cell Nucleus metabolism, Cytosol metabolism, Disease Models, Animal, Humans, Neurodegenerative Diseases genetics, Neurodegenerative Diseases pathology, Protein Folding, Protein Transport, RNA Interference, alpha-Synuclein chemistry, alpha-Synuclein genetics, Neurodegenerative Diseases metabolism, alpha-Synuclein metabolism
- Abstract
Caenorhabditis elegans is widely used to investigate biological processes related to health and disease. Multiple C. elegans models for human neurodegenerative diseases do exist, including those expressing human α-synuclein. Even though these models do not feature all pathological and molecular hallmarks of the disease they mimic, they allow for the identification and dissection of molecular pathways that are involved. In line with this, genetic screens have yielded multiple modifiers of proteotoxicity in C. elegans models for neurodegenerative diseases. Here, we describe a set of common screening approaches and tools that can be used to study synucleinopathies and other neurodegenerative diseases in C. elegans. RNA interference and mutagenesis screens can be used to find genes that affect proteotoxicity, while relatively simple molecular, cellular (fractionation studies), metabolic (respiration studies), and behavioral (thrashing and crawling) readouts can be used to study the effects of disease proteins and modifiers more closely.
- Published
- 2019
- Full Text
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12. Nuclear/Cytoplasmic Fractionation of Proteins from Caenorhabditis elegans .
- Author
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Mata-Cabana A, Sin O, Seinstra RI, and Nollen EAA
- Abstract
C. elegans is widely used to investigate biological processes related to health and disease. To study protein localization, fluorescently-tagged proteins can be used in vivo or immunohistochemistry can be performed in whole worms. Here, we describe a technique to localize a protein of interest at a subcellular level in C. elegans lysates, which can give insight into the location, function and/or toxicity of proteins., Competing Interests: Competing interests The authors declare no conflicts of interest or competing interests.
- Published
- 2018
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13. Filter Retardation Assay for Detecting and Quantifying Polyglutamine Aggregates Using Caenorhabditis elegans Lysates.
- Author
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Sin O, Mata-Cabana A, Seinstra RI, and Nollen EAA
- Abstract
Protein aggregation is a hallmark of several neurodegenerative diseases and is associated with impaired protein homeostasis. This imbalance is caused by the loss of the protein's native conformation, which ultimately results in its aggregation or abnormal localization within the cell. Using a C. elegans model of polyglutamine diseases, we describe in detail the filter retardation assay, a method that captures protein aggregates in a cellulose acetate membrane and allows its detection and quantification by immunoblotting., Competing Interests: Competing interests The authors declare no conflicts of interest or competing interests.
- Published
- 2018
- Full Text
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14. Identification of an RNA Polymerase III Regulator Linked to Disease-Associated Protein Aggregation.
- Author
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Sin O, de Jong T, Mata-Cabana A, Kudron M, Zaini MA, Aprile FA, Seinstra RI, Stroo E, Prins RW, Martineau CN, Wang HH, Hogewerf W, Steinhof A, Wanker EE, Vendruscolo M, Calkhoven CF, Reinke V, Guryev V, and Nollen EA
- Subjects
- Active Transport, Cell Nucleus, Animals, Animals, Genetically Modified, Binding Sites, Caenorhabditis elegans genetics, Caenorhabditis elegans Proteins genetics, Cell Nucleus enzymology, Cytosol enzymology, Disease Models, Animal, Neurodegenerative Diseases genetics, Neurodegenerative Diseases pathology, Promoter Regions, Genetic, Protein Binding, RNA Interference, RNA Polymerase III genetics, RNA, Small Untranslated genetics, RNA, Small Untranslated metabolism, Transcription Factors genetics, Transcription, Genetic, Caenorhabditis elegans enzymology, Caenorhabditis elegans Proteins metabolism, Neurodegenerative Diseases enzymology, Peptides metabolism, Protein Aggregates, Protein Aggregation, Pathological, RNA Polymerase III metabolism, Transcription Factors metabolism
- Abstract
Protein aggregation is associated with age-related neurodegenerative disorders, such as Alzheimer's and polyglutamine diseases. As a causal relationship between protein aggregation and neurodegeneration remains elusive, understanding the cellular mechanisms regulating protein aggregation will help develop future treatments. To identify such mechanisms, we conducted a forward genetic screen in a C. elegans model of polyglutamine aggregation and identified the protein MOAG-2/LIR-3 as a driver of protein aggregation. In the absence of polyglutamine, MOAG-2/LIR-3 regulates the RNA polymerase III-associated transcription of small non-coding RNAs. This regulation is lost in the presence of polyglutamine, which mislocalizes MOAG-2/LIR-3 from the nucleus to the cytosol. We then show biochemically that MOAG-2/LIR-3 can also catalyze the aggregation of polyglutamine-expanded huntingtin. These results suggest that polyglutamine can induce an aggregation-promoting activity of MOAG-2/LIR-3 in the cytosol. The concept that certain aggregation-prone proteins can convert other endogenous proteins into drivers of aggregation and toxicity adds to the understanding of how cellular homeostasis can be deteriorated in protein misfolding diseases., (Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.)
- Published
- 2017
- Full Text
- View/download PDF
15. Discovery and functional prioritization of Parkinson's disease candidate genes from large-scale whole exome sequencing.
- Author
-
Jansen IE, Ye H, Heetveld S, Lechler MC, Michels H, Seinstra RI, Lubbe SJ, Drouet V, Lesage S, Majounie E, Gibbs JR, Nalls MA, Ryten M, Botia JA, Vandrovcova J, Simon-Sanchez J, Castillo-Lizardo M, Rizzu P, Blauwendraat C, Chouhan AK, Li Y, Yogi P, Amin N, van Duijn CM, Morris HR, Brice A, Singleton AB, David DC, Nollen EA, Jain S, Shulman JM, and Heutink P
- Subjects
- Adolescent, Adult, Animals, Animals, Genetically Modified, Caenorhabditis elegans genetics, Case-Control Studies, Cells, Cultured, Child, Disease Models, Animal, Drosophila melanogaster genetics, Exome, Humans, Middle Aged, RNA Interference, Young Adult, Genetic Predisposition to Disease, High-Throughput Nucleotide Sequencing methods, Parkinson Disease genetics, Sequence Analysis, DNA methods, alpha-Synuclein genetics
- Abstract
Background: Whole-exome sequencing (WES) has been successful in identifying genes that cause familial Parkinson's disease (PD). However, until now this approach has not been deployed to study large cohorts of unrelated participants. To discover rare PD susceptibility variants, we performed WES in 1148 unrelated cases and 503 control participants. Candidate genes were subsequently validated for functions relevant to PD based on parallel RNA-interference (RNAi) screens in human cell culture and Drosophila and C. elegans models., Results: Assuming autosomal recessive inheritance, we identify 27 genes that have homozygous or compound heterozygous loss-of-function variants in PD cases. Definitive replication and confirmation of these findings were hindered by potential heterogeneity and by the rarity of the implicated alleles. We therefore looked for potential genetic interactions with established PD mechanisms. Following RNAi-mediated knockdown, 15 of the genes modulated mitochondrial dynamics in human neuronal cultures and four candidates enhanced α-synuclein-induced neurodegeneration in Drosophila. Based on complementary analyses in independent human datasets, five functionally validated genes-GPATCH2L, UHRF1BP1L, PTPRH, ARSB, and VPS13C-also showed evidence consistent with genetic replication., Conclusions: By integrating human genetic and functional evidence, we identify several PD susceptibility gene candidates for further investigation. Our approach highlights a powerful experimental strategy with broad applicability for future studies of disorders with complex genetic etiologies.
- Published
- 2017
- Full Text
- View/download PDF
16. Identification of an evolutionary conserved structural loop that is required for the enzymatic and biological function of tryptophan 2,3-dioxygenase.
- Author
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Michels H, Seinstra RI, Uitdehaag JC, Koopman M, van Faassen M, Martineau CN, Kema IP, Buijsman R, and Nollen EA
- Subjects
- Aging, Amino Acid Motifs, Amino Acid Sequence, Animals, CRISPR-Cas Systems genetics, Caenorhabditis elegans Proteins chemistry, Caenorhabditis elegans Proteins genetics, Heme chemistry, Heme metabolism, Humans, Locomotion, Longevity, Mutagenesis, Protein Binding, Protein Structure, Tertiary, Sequence Alignment, Tryptophan Oxygenase chemistry, Tryptophan Oxygenase genetics, Caenorhabditis elegans enzymology, Caenorhabditis elegans Proteins metabolism, Evolution, Molecular, Tryptophan Oxygenase metabolism
- Abstract
The enzyme TDO (tryptophan 2,3-dioxygenase; TDO-2 in Caenorhabditis elegans) is a potential therapeutic target to cancer but is also thought to regulate proteotoxic events seen in the progression of neurodegenerative diseases. To better understand its function and develop specific compounds that target TDO we need to understand the structure of this molecule. In C. elegans we compared multiple different CRISPR/Cas9-induced tdo-2 deletion mutants and identified a motif of three amino acids (PLD) that is required for the enzymatic conversion of tryptophan to N-formylkynurenine. Loss of TDO-2's enzymatic activity in PDL deletion mutants was accompanied by an increase in motility during aging and a prolonged lifespan, which is in line with the previously observed phenotypes induced by a knockdown of the full enzyme. Comparison of sequence structures suggests that blocking this motif might interfere with haem binding, which is essential for the enzyme's activity. The fact that these three residues are situated in an evolutionary conserved structural loop of the enzyme suggests that the findings can be translated to humans. The identification of this specific loop region in TDO-2-essential for its catalytic function-will aid in the design of novel inhibitors to treat diseases in which the TDO enzyme is overexpressed or hyperactive.
- Published
- 2016
- Full Text
- View/download PDF
17. Forced activation of Cdk1 via wee1 inhibition impairs homologous recombination.
- Author
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Krajewska M, Heijink AM, Bisselink YJ, Seinstra RI, Silljé HH, de Vries EG, and van Vugt MA
- Subjects
- DNA Damage, Enzyme Activation drug effects, Humans, MCF-7 Cells, Pyrazoles pharmacology, Pyrimidines pharmacology, Pyrimidinones, Quinolines pharmacology, Thiazoles pharmacology, CDC2 Protein Kinase metabolism, Cell Cycle Proteins antagonists & inhibitors, Homologous Recombination drug effects, Nuclear Proteins antagonists & inhibitors, Protein Kinase Inhibitors pharmacology, Protein-Tyrosine Kinases antagonists & inhibitors
- Abstract
In response to DNA breaks, the 'DNA damage response' provokes a cell cycle arrest to facilitate DNA repair. Recent findings have indicated that cells can respond to DNA damage throughout the cell cycle, except during mitosis. Specifically, various mitotic kinases, including Cdk1, Aurora A and Plk1, were shown to inactivate key DNA damage checkpoint proteins when cells enter mitosis. Aberrant activation of mitotic kinases during interphase could therefore modulate cellular responses to DNA damage. In this study, our aim was to determine how aberrant activation of Cdk1 affects the cellular responses to DNA damage. We used Wee1 inhibition, using MK-1775, to force Cdk1 activation, which did not cause cytotoxicity in non-transformed cells. Instead, it accelerated mitotic entry and caused radio sensitization in p53-defective cancer cells, but not in p53-proficient cancer cells. Interestingly, we showed that Wee1 inhibition leads to elevation of Cdk1 activity in interphase cells. When we subsequently analyzed DNA damage responses in cells with forced Cdk1 activation, we observed a marked reduction of 53BP1 at sites of DNA damage along with an increase in γ-H2AX staining after irradiation, indicative of defective DNA repair. Indeed, when DNA repair was analyzed using in vivo endonuclease-induced homologous recombination (HR) assays, compromised DNA repair after Wee1 inhibition was confirmed. This defect in HR was accompanied by increased phosphorylation of BRCA2 at the Cdk1 phosphorylation site S3291. Taken together, our results indicate that Wee1 inhibition leads to forced Cdk1 activation in interphase cells, which interferes with normal DNA damage responses.
- Published
- 2013
- Full Text
- View/download PDF
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