1
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Breuer J, Ferreira DEA, Kramer M, Bollermann J, Nowrousian M. Functional analysis of chromatin-associated proteins in Sordaria macrospora reveals similar roles for RTT109 and ASF1 in development and DNA damage response. G3 (BETHESDA, MD.) 2024; 14:jkae019. [PMID: 38261383 PMCID: PMC10917505 DOI: 10.1093/g3journal/jkae019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 01/16/2024] [Accepted: 01/16/2024] [Indexed: 01/24/2024]
Abstract
We performed a functional analysis of two potential partners of ASF1, a highly conserved histone chaperone that plays a crucial role in the sexual development and DNA damage resistance in the ascomycete Sordaria macrospora. ASF1 is known to be involved in nucleosome assembly and disassembly, binding histones H3 and H4 during transcription, replication and DNA repair and has direct and indirect roles in histone recycling and modification as well as DNA methylation, acting as a chromatin modifier hub for a large network of chromatin-associated proteins. Here, we functionally characterized two of these proteins, RTT109 and CHK2. RTT109 is a fungal-specific histone acetyltransferase, while CHK2 is an ortholog to PRD-4, a checkpoint kinase of Neurospora crassa that performs similar cell cycle checkpoint functions as yeast RAD53. Through the generation and characterization of deletion mutants, we discovered striking similarities between RTT109 and ASF1 in terms of their contributions to sexual development, histone acetylation, and protection against DNA damage. Phenotypic observations revealed a developmental arrest at the same stage in Δrtt109 and Δasf1 strains, accompanied by a loss of H3K56 acetylation, as detected by western blot analysis. Deletion mutants of rtt109 and asf1 are sensitive to the DNA damaging agent methyl methanesulfonate, but not hydroxyurea. In contrast, chk2 mutants are fertile and resistant to methyl methanesulfonate, but not hydroxyurea. Our findings suggest a close functional association between ASF1 and RTT109 in the context of development, histone modification, and DNA damage response, while indicating a role for CHK2 in separate pathways of the DNA damage response.
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Affiliation(s)
- Jan Breuer
- Department of Molecular and Cellular Botany, Ruhr University Bochum, Universitätsstr. 150, 44801 Bochum, Germany
| | | | - Mike Kramer
- Department of Molecular and Cellular Botany, Ruhr University Bochum, Universitätsstr. 150, 44801 Bochum, Germany
| | - Jonas Bollermann
- Department of Molecular and Cellular Botany, Ruhr University Bochum, Universitätsstr. 150, 44801 Bochum, Germany
| | - Minou Nowrousian
- Department of Molecular and Cellular Botany, Ruhr University Bochum, Universitätsstr. 150, 44801 Bochum, Germany
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2
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Evstyukhina TA, Alekseeva EA, Peshekhonov VT, Skobeleva II, Fedorov DV, Korolev VG. The Role of Chromatin Assembly Factors in Induced Mutagenesis at Low Levels of DNA Damage. Genes (Basel) 2023; 14:1242. [PMID: 37372422 DOI: 10.3390/genes14061242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 06/08/2023] [Accepted: 06/08/2023] [Indexed: 06/29/2023] Open
Abstract
The problem of low-dose irradiation has been discussed in the scientific literature for several decades, but it is impossible to come to a generally accepted conclusion about the presence of any specific features of low-dose irradiation in contrast to acute irradiation. We were interested in the effect of low doses of UV radiation on the physiological processes, including repair processes in cells of the yeast Saccharomyces cerevisiae, in contrast to high doses of radiation. Cells utilize excision repair and DNA damage tolerance pathways without significant delay of the cell cycle to address low levels of DNA damage (such as spontaneous base lesions). For genotoxic agents, there is a dose threshold below which checkpoint activation is minimal despite the measurable activity of the DNA repair pathways. Here we report that at ultra-low levels of DNA damage, the role of the error-free branch of post-replicative repair in protection against induced mutagenesis is key. However, with an increase in the levels of DNA damage, the role of the error-free repair branch is rapidly decreasing. We demonstrate that with an increase in the amount of DNA damage from ultra-small to high, asf1Δ-specific mutagenesis decreases catastrophically. A similar dependence is observed for mutants of gene-encoding subunits of the NuB4 complex. Elevated levels of dNTPs caused by the inactivation of the SML1 gene are responsible for high spontaneous reparative mutagenesis. The Rad53 kinase plays a key role in reparative UV mutagenesis at high doses, as well as in spontaneous repair mutagenesis at ultra-low DNA damage levels.
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Affiliation(s)
- Tatiyana A Evstyukhina
- Chromatin and Repair Genetic Research Group of the Laboratory of Experimental Genetics, Department of Molecular and Radiation Biophysics, Petersburg Nuclear Physics Institute Named by B.P. Konstantinov of National Research Centre "Kurchatov Institute", 188300 Gatchina, Russia
- Laboratory of Molecular Genetic and Recombination Technologies, Kurchatov Genome Center-Petersburg Nuclear Physics Institute, 188300 Gatchina, Russia
| | - Elena A Alekseeva
- Chromatin and Repair Genetic Research Group of the Laboratory of Experimental Genetics, Department of Molecular and Radiation Biophysics, Petersburg Nuclear Physics Institute Named by B.P. Konstantinov of National Research Centre "Kurchatov Institute", 188300 Gatchina, Russia
- Laboratory of Molecular Genetic and Recombination Technologies, Kurchatov Genome Center-Petersburg Nuclear Physics Institute, 188300 Gatchina, Russia
| | - Vyacheslav T Peshekhonov
- Chromatin and Repair Genetic Research Group of the Laboratory of Experimental Genetics, Department of Molecular and Radiation Biophysics, Petersburg Nuclear Physics Institute Named by B.P. Konstantinov of National Research Centre "Kurchatov Institute", 188300 Gatchina, Russia
- Laboratory of Molecular Genetic and Recombination Technologies, Kurchatov Genome Center-Petersburg Nuclear Physics Institute, 188300 Gatchina, Russia
| | - Irina I Skobeleva
- Chromatin and Repair Genetic Research Group of the Laboratory of Experimental Genetics, Department of Molecular and Radiation Biophysics, Petersburg Nuclear Physics Institute Named by B.P. Konstantinov of National Research Centre "Kurchatov Institute", 188300 Gatchina, Russia
| | - Dmitriy V Fedorov
- Chromatin and Repair Genetic Research Group of the Laboratory of Experimental Genetics, Department of Molecular and Radiation Biophysics, Petersburg Nuclear Physics Institute Named by B.P. Konstantinov of National Research Centre "Kurchatov Institute", 188300 Gatchina, Russia
| | - Vladimir G Korolev
- Chromatin and Repair Genetic Research Group of the Laboratory of Experimental Genetics, Department of Molecular and Radiation Biophysics, Petersburg Nuclear Physics Institute Named by B.P. Konstantinov of National Research Centre "Kurchatov Institute", 188300 Gatchina, Russia
- Laboratory of Molecular Genetic and Recombination Technologies, Kurchatov Genome Center-Petersburg Nuclear Physics Institute, 188300 Gatchina, Russia
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3
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Simon B, Lou HJ, Huet-Calderwood C, Shi G, Boggon TJ, Turk BE, Calderwood DA. Tousled-like kinase 2 targets ASF1 histone chaperones through client mimicry. Nat Commun 2022; 13:749. [PMID: 35136069 PMCID: PMC8826447 DOI: 10.1038/s41467-022-28427-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 01/25/2022] [Indexed: 12/26/2022] Open
Abstract
Tousled-like kinases (TLKs) are nuclear serine-threonine kinases essential for genome maintenance and proper cell division in animals and plants. A major function of TLKs is to phosphorylate the histone chaperone proteins ASF1a and ASF1b to facilitate DNA replication-coupled nucleosome assembly, but how TLKs selectively target these critical substrates is unknown. Here, we show that TLK2 selectivity towards ASF1 substrates is achieved in two ways. First, the TLK2 catalytic domain recognizes consensus phosphorylation site motifs in the ASF1 C-terminal tail. Second, a short sequence at the TLK2 N-terminus docks onto the ASF1a globular N-terminal domain in a manner that mimics its histone H3 client. Disrupting either catalytic or non-catalytic interactions through mutagenesis hampers ASF1 phosphorylation by TLK2 and cell growth. Our results suggest that the stringent selectivity of TLKs for ASF1 is enforced by an unusual interaction mode involving mutual recognition of a short sequence motifs by both kinase and substrate. Tousled-like kinase 2 (TLK2) phosphorylates ASF1 histone chaperones to promote nucleosome assembly in S phase. Here, the authors show that TLK2 targets ASF1 by simulating its client protein histone H3, exploiting a primordial protein interaction surface for regulatory control.
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Affiliation(s)
- Bertrand Simon
- Department of Pharmacology, Yale School of Medicine, New Haven, CT, USA
| | - Hua Jane Lou
- Department of Pharmacology, Yale School of Medicine, New Haven, CT, USA
| | | | - Guangda Shi
- Department of Pharmacology, Yale School of Medicine, New Haven, CT, USA
| | - Titus J Boggon
- Department of Pharmacology, Yale School of Medicine, New Haven, CT, USA.,Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Benjamin E Turk
- Department of Pharmacology, Yale School of Medicine, New Haven, CT, USA.
| | - David A Calderwood
- Department of Pharmacology, Yale School of Medicine, New Haven, CT, USA. .,Department of Cell Biology, Yale School of Medicine, New Haven, CT, USA.
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4
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Bhagwat M, Nagar S, Kaur P, Mehta R, Vancurova I, Vancura A. Replication stress inhibits synthesis of histone mRNAs in yeast by removing Spt10p and Spt21p from the histone promoters. J Biol Chem 2021; 297:101246. [PMID: 34582893 PMCID: PMC8551654 DOI: 10.1016/j.jbc.2021.101246] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 09/17/2021] [Accepted: 09/23/2021] [Indexed: 12/27/2022] Open
Abstract
Proliferating cells coordinate histone and DNA synthesis to maintain correct stoichiometry for chromatin assembly. Histone mRNA levels must be repressed when DNA replication is inhibited to prevent toxicity and genome instability due to free non-chromatinized histone proteins. In mammalian cells, replication stress triggers degradation of histone mRNAs, but it is unclear if this mechanism is conserved from other species. The aim of this study was to identify the histone mRNA decay pathway in the yeast Saccharomyces cerevisiae and determine the mechanism by which DNA replication stress represses histone mRNAs. Using reverse transcription-quantitative PCR and chromatin immunoprecipitation–quantitative PCR, we show here that histone mRNAs can be degraded by both 5′ → 3′ and 3′ → 5′ pathways; however, replication stress does not trigger decay of histone mRNA in yeast. Rather, replication stress inhibits transcription of histone genes by removing the histone gene–specific transcription factors Spt10p and Spt21p from histone promoters, leading to disassembly of the preinitiation complexes and eviction of RNA Pol II from histone genes by a mechanism facilitated by checkpoint kinase Rad53p and histone chaperone Asf1p. In contrast, replication stress does not remove SCB-binding factor transcription complex, another activator of histone genes, from the histone promoters, suggesting that Spt10p and Spt21p have unique roles in the transcriptional downregulation of histone genes during replication stress. Together, our data show that, unlike in mammalian cells, replication stress in yeast does not trigger decay of histone mRNAs but inhibits histone transcription.
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Affiliation(s)
- Madhura Bhagwat
- Department of Biological Sciences, St John's University, Queens, New York, USA
| | - Shreya Nagar
- Department of Biological Sciences, St John's University, Queens, New York, USA
| | - Pritpal Kaur
- Department of Biological Sciences, St John's University, Queens, New York, USA
| | - Riddhi Mehta
- Department of Biological Sciences, St John's University, Queens, New York, USA
| | - Ivana Vancurova
- Department of Biological Sciences, St John's University, Queens, New York, USA
| | - Ales Vancura
- Department of Biological Sciences, St John's University, Queens, New York, USA.
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5
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Deng K, Feng W, Liu X, Su X, Zuo E, Du S, Huang Y, Shi D, Lu F. Anti-silencing factor 1A is associated with genome stability maintenance of mouse preimplantation embryos†. Biol Reprod 2020; 102:817-827. [PMID: 31916576 DOI: 10.1093/biolre/ioaa001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 10/07/2019] [Accepted: 01/03/2020] [Indexed: 12/26/2022] Open
Abstract
Genome stability is critical for the normal development of preimplantation embryos, as DNA damages may result in mutation and even embryo lethality. Anti-silencing factor 1A (ASF1A) is a histone chaperone and enriched in the MII oocytes as a maternal factor, which may be associated with the maintenance of genome stability. Thus, this study was undertaken to explore the role of ASF1A in maintaining the genome stability of early mouse embryos. The ASF1A expressed in the preimplantation embryos and displayed a dynamic pattern throughout the early embryonic development. Inhibition of ASF1A expression decreased embryonic development and increased DNA damages. Overexpression of ASF1A improved the developmental potential and decreased DNA damages. When 293T cells that had been integrated with RGS-NHEJ were co-transfected with plasmids of pcDNA3.1-ASF1A, gRNA-NHEJ, and hCas9, less cells expressed eGFP, indicating that non-homologous end joining was reduced by ASF1A. When 293T cells were co-transfected with plasmids of HR-donor, gRNA-HR, hCas9, and pcDNA3.1-ASF1A, more cells expressed eGFP, indicating that homologous recombination (HR) was enhanced by ASF1A. These results indicate that ASF1A may be associated with the genome stability maintenance of early mouse embryos and this action may be mediated by promoting DNA damage repair through HR pathway.
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Affiliation(s)
- Kai Deng
- Guangxi High Education Key Laboratory for Animal Reproduction and Biotechnology, State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi University, Nanning, China and
| | - Wanyou Feng
- Guangxi High Education Key Laboratory for Animal Reproduction and Biotechnology, State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi University, Nanning, China and
| | - Xiaohua Liu
- Guangxi High Education Key Laboratory for Animal Reproduction and Biotechnology, State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi University, Nanning, China and
| | - Xiaoping Su
- Guangxi High Education Key Laboratory for Animal Reproduction and Biotechnology, State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi University, Nanning, China and
| | - Erwei Zuo
- Center for Animal Genomics, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China
| | - Shanshan Du
- Guangxi High Education Key Laboratory for Animal Reproduction and Biotechnology, State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi University, Nanning, China and
| | - Yongjun Huang
- Guangxi High Education Key Laboratory for Animal Reproduction and Biotechnology, State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi University, Nanning, China and
| | - Deshun Shi
- Guangxi High Education Key Laboratory for Animal Reproduction and Biotechnology, State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi University, Nanning, China and
| | - Fenghua Lu
- Guangxi High Education Key Laboratory for Animal Reproduction and Biotechnology, State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi University, Nanning, China and
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6
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Distinct associations of the Saccharomyces cerevisiae Rad9 protein link Mac1-regulated transcription to DNA repair. Curr Genet 2019; 66:531-548. [PMID: 31784768 DOI: 10.1007/s00294-019-01047-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 11/06/2019] [Accepted: 11/18/2019] [Indexed: 12/12/2022]
Abstract
While it is known that ScRad9 DNA damage checkpoint protein is recruited to damaged DNA by recognizing specific histone modifications, here we report a different way of Rad9 recruitment on chromatin under non DNA damaging conditions. We found Rad9 to bind directly with the copper-modulated transcriptional activator Mac1, suppressing both its DNA binding and transactivation functions. Rad9 was recruited to active Mac1-target promoters (CTR1, FRE1) and along CTR1 coding region following the association pattern of RNA polymerase (Pol) II. Hir1 histone chaperone also interacted directly with Rad9 and was partly required for its localization throughout CTR1 gene. Moreover, Mac1-dependent transcriptional initiation was necessary and sufficient for Rad9 recruitment to the heterologous ACT1 coding region. In addition to Rad9, Rad53 kinase also localized to CTR1 coding region in a Rad9-dependent manner. Our data provide an example of a yeast DNA-binding transcriptional activator that interacts directly with a DNA damage checkpoint protein in vivo and is functionally restrained by this protein, suggesting a new role for Rad9 in connecting factors of the transcription machinery with the DNA repair pathway under unchallenged conditions.
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7
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Santos SM, Hartman JL. A yeast phenomic model for the influence of Warburg metabolism on genetic buffering of doxorubicin. Cancer Metab 2019; 7:9. [PMID: 31660150 PMCID: PMC6806529 DOI: 10.1186/s40170-019-0201-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 09/03/2019] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND The influence of the Warburg phenomenon on chemotherapy response is unknown. Saccharomyces cerevisiae mimics the Warburg effect, repressing respiration in the presence of adequate glucose. Yeast phenomic experiments were conducted to assess potential influences of Warburg metabolism on gene-drug interaction underlying the cellular response to doxorubicin. Homologous genes from yeast phenomic and cancer pharmacogenomics data were analyzed to infer evolutionary conservation of gene-drug interaction and predict therapeutic relevance. METHODS Cell proliferation phenotypes (CPPs) of the yeast gene knockout/knockdown library were measured by quantitative high-throughput cell array phenotyping (Q-HTCP), treating with escalating doxorubicin concentrations under conditions of respiratory or glycolytic metabolism. Doxorubicin-gene interaction was quantified by departure of CPPs observed for the doxorubicin-treated mutant strain from that expected based on an interaction model. Recursive expectation-maximization clustering (REMc) and Gene Ontology (GO)-based analyses of interactions identified functional biological modules that differentially buffer or promote doxorubicin cytotoxicity with respect to Warburg metabolism. Yeast phenomic and cancer pharmacogenomics data were integrated to predict differential gene expression causally influencing doxorubicin anti-tumor efficacy. RESULTS Yeast compromised for genes functioning in chromatin organization, and several other cellular processes are more resistant to doxorubicin under glycolytic conditions. Thus, the Warburg transition appears to alleviate requirements for cellular functions that buffer doxorubicin cytotoxicity in a respiratory context. We analyzed human homologs of yeast genes exhibiting gene-doxorubicin interaction in cancer pharmacogenomics data to predict causality for differential gene expression associated with doxorubicin cytotoxicity in cancer cells. This analysis suggested conserved cellular responses to doxorubicin due to influences of homologous recombination, sphingolipid homeostasis, telomere tethering at nuclear periphery, actin cortical patch localization, and other gene functions. CONCLUSIONS Warburg status alters the genetic network required for yeast to buffer doxorubicin toxicity. Integration of yeast phenomic and cancer pharmacogenomics data suggests evolutionary conservation of gene-drug interaction networks and provides a new experimental approach to model their influence on chemotherapy response. Thus, yeast phenomic models could aid the development of precision oncology algorithms to predict efficacious cytotoxic drugs for cancer, based on genetic and metabolic profiles of individual tumors.
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Affiliation(s)
- Sean M. Santos
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL USA
| | - John L. Hartman
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL USA
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8
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Segura-Bayona S, Stracker TH. The Tousled-like kinases regulate genome and epigenome stability: implications in development and disease. Cell Mol Life Sci 2019; 76:3827-3841. [PMID: 31302748 PMCID: PMC11105529 DOI: 10.1007/s00018-019-03208-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 06/05/2019] [Accepted: 06/24/2019] [Indexed: 02/06/2023]
Abstract
The Tousled-like kinases (TLKs) are an evolutionarily conserved family of serine-threonine kinases that have been implicated in DNA replication, DNA repair, transcription, chromatin structure, viral latency, cell cycle checkpoint control and chromosomal stability in various organisms. The functions of the TLKs appear to depend largely on their ability to regulate the H3/H4 histone chaperone ASF1, although numerous TLK substrates have been proposed. Over the last few years, a clearer picture of TLK function has emerged through the identification of new partners, the definition of specific roles in development and the elucidation of their structural and biochemical properties. In addition, the TLKs have been clearly linked to human disease; both TLK1 and TLK2 are frequently amplified in human cancers and TLK2 mutations have been identified in patients with neurodevelopmental disorders characterized by intellectual disability (ID), autism spectrum disorder (ASD) and microcephaly. A better understanding of the substrates, regulation and diverse roles of the TLKs is needed to understand their functions in neurodevelopment and determine if they are viable targets for cancer therapy. In this review, we will summarize current knowledge of TLK biology and its potential implications in development and disease.
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Affiliation(s)
- Sandra Segura-Bayona
- Department of Oncology, Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, C/Baldiri Reixac 10, 08028, Barcelona, Spain.
- The Francis Crick Institute, London, UK.
| | - Travis H Stracker
- Department of Oncology, Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, C/Baldiri Reixac 10, 08028, Barcelona, Spain.
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9
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Lercher L, Danilenko N, Kirkpatrick J, Carlomagno T. Structural characterization of the Asf1-Rtt109 interaction and its role in histone acetylation. Nucleic Acids Res 2019; 46:2279-2289. [PMID: 29300933 PMCID: PMC5861439 DOI: 10.1093/nar/gkx1283] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 12/18/2017] [Indexed: 02/03/2023] Open
Abstract
Acetylation of histone H3 at lysine-56 by the histone acetyltransferase Rtt109 in lower eukaryotes is important for maintaining genomic integrity and is required for C. albicans pathogenicity. Rtt109 is activated by association with two different histone chaperones, Vps75 and Asf1, through an unknown mechanism. Here, we reveal that the Rtt109 C-terminus interacts directly with Asf1 and elucidate the structural basis of this interaction. In addition, we find that the H3 N-terminus can interact via the same interface on Asf1, leading to a competition between the two interaction partners. This, together with the recruitment and position of the substrate, provides an explanation of the role of the Rtt109 C-terminus in Asf1-dependent Rtt109 activation.
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Affiliation(s)
- Lukas Lercher
- BMWZ and Institute of Organic Chemistry, Leibniz Universität Hannover, Hannover, Germany
| | - Nataliya Danilenko
- BMWZ and Institute of Organic Chemistry, Leibniz Universität Hannover, Hannover, Germany
| | - John Kirkpatrick
- BMWZ and Institute of Organic Chemistry, Leibniz Universität Hannover, Hannover, Germany
| | - Teresa Carlomagno
- BMWZ and Institute of Organic Chemistry, Leibniz Universität Hannover, Hannover, Germany.,Research Group of NMR-based Structural Chemistry, Helmholtz Centre for Infection Research, Braunschweig, Germany
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10
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Huang TH, Fowler F, Chen CC, Shen ZJ, Sleckman B, Tyler JK. The Histone Chaperones ASF1 and CAF-1 Promote MMS22L-TONSL-Mediated Rad51 Loading onto ssDNA during Homologous Recombination in Human Cells. Mol Cell 2018; 69:879-892.e5. [PMID: 29478807 DOI: 10.1016/j.molcel.2018.01.031] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Revised: 11/27/2017] [Accepted: 01/23/2018] [Indexed: 10/18/2022]
Abstract
The access-repair-restore model for the role of chromatin in DNA repair infers that chromatin is a mere obstacle to DNA repair. However, here we show that blocking chromatin assembly, via knockdown of the histone chaperones ASF1 or CAF-1 or a mutation that prevents ASF1A binding to histones, hinders Rad51 loading onto ssDNA during homologous recombination. This is a consequence of reduced recruitment of the Rad51 loader MMS22L-TONSL to ssDNA, resulting in persistent RPA foci, extensive DNA end resection, persistent activation of the ATR-Chk1 pathway, and cell cycle arrest. In agreement, histones occupy ssDNA during DNA repair in yeast. We also uncovered DNA-PKcs-dependent DNA damage-induced ASF1A phosphorylation, which enhances chromatin assembly, promoting MMS22L-TONSL recruitment and, hence, Rad51 loading. We propose that transient assembly of newly synthesized histones onto ssDNA serves to recruit MMS22L-TONSL to efficiently form the Rad51 nucleofilament for strand invasion, suggesting an active role of chromatin assembly in homologous recombination.
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Affiliation(s)
- Ting-Hsiang Huang
- Weill Cornell Medicine, Department of Pathology and Laboratory Medicine, New York, NY 10065, USA
| | - Faith Fowler
- Weill Cornell Medicine, Department of Pathology and Laboratory Medicine, New York, NY 10065, USA
| | - Chin-Chuan Chen
- Graduate Institute of Natural Products, Chang Gung University, Taoyuan 333, Taiwan
| | - Zih-Jie Shen
- Weill Cornell Medicine, Department of Pathology and Laboratory Medicine, New York, NY 10065, USA
| | - Barry Sleckman
- Weill Cornell Medicine, Department of Pathology and Laboratory Medicine, New York, NY 10065, USA
| | - Jessica K Tyler
- Weill Cornell Medicine, Department of Pathology and Laboratory Medicine, New York, NY 10065, USA.
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11
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Tsabar M, Waterman DP, Aguilar F, Katsnelson L, Eapen VV, Memisoglu G, Haber JE. Asf1 facilitates dephosphorylation of Rad53 after DNA double-strand break repair. Genes Dev 2017; 30:1211-24. [PMID: 27222517 PMCID: PMC4888841 DOI: 10.1101/gad.280685.116] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 04/29/2016] [Indexed: 02/07/2023]
Abstract
In this study, Tsabar et al. investigated how the DNA damage checkpoint is extinguished and found that dissociation of histone H3 from Asf1, a histone chaperone, is required for efficient recovery. They also show that Asf1 is required for complete dephosphorylation of Rad53 when the upstream DNA damage checkpoint signaling is turned off, providing new insights into the mechanisms regulating the response to DNA damage. To allow for sufficient time to repair DNA double-stranded breaks (DSBs), eukaryotic cells activate the DNA damage checkpoint. In budding yeast, Rad53 (mammalian Chk2) phosphorylation parallels the persistence of the unrepaired DSB and is extinguished when repair is complete in a process termed recovery or when the cells adapt to the DNA damage checkpoint. A strain containing a slowly repaired DSB does not require the histone chaperone Asf1 to resume cell cycle progression after DSB repair. When a second, rapidly repairable DSB is added to this strain, Asf1 becomes required for recovery. Recovery from two repairable DSBs also depends on the histone acetyltransferase Rtt109 and the cullin subunit Rtt101, both of which modify histone H3 that is associated with Asf1. We show that dissociation of histone H3 from Asf1 is required for efficient recovery and that Asf1 is required for complete dephosphorylation of Rad53 when the upstream DNA damage checkpoint signaling is turned off. Our data suggest that the requirements for recovery from the DNA damage checkpoint become more stringent with increased levels of damage and that Asf1 plays a histone chaperone-independent role in facilitating complete Rad53 dephosphorylation following repair.
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Affiliation(s)
- Michael Tsabar
- Department of Biology, Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, Massachusetts 02454, USA
| | - David P Waterman
- Department of Biology, Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, Massachusetts 02454, USA
| | - Fiona Aguilar
- Department of Biology, Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, Massachusetts 02454, USA
| | - Lizabeth Katsnelson
- Department of Biology, Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, Massachusetts 02454, USA
| | - Vinay V Eapen
- Department of Biology, Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, Massachusetts 02454, USA
| | - Gonen Memisoglu
- Department of Biology, Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, Massachusetts 02454, USA
| | - James E Haber
- Department of Biology, Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, Massachusetts 02454, USA
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12
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Wright DE, Kao CF. (Ubi)quitin' the h2bit: recent insights into the roles of H2B ubiquitylation in DNA replication and transcription. Epigenetics 2015; 10:122-6. [PMID: 25603102 DOI: 10.1080/15592294.2014.1003750] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The reversible ubiquitylation of histone H2B has long been known to regulate gene transcription, and is now understood to modulate DNA replication as well. In this review, we describe how recent, genome-wide analyses have demonstrated that this histone mark has further reaching effects on transcription and replication than once thought. We also consider the ongoing efforts to elucidate the molecular mechanisms by which H2B ubiquitylation affects processes on the DNA template, and outline the various hypothetical scenarios.
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Affiliation(s)
- Duncan E Wright
- a Institute of Cellular and Organismic Biology; Academia Sinica ; Taipei , Taiwan
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Prado F, Clemente-Ruiz M. Nucleosome assembly and genome integrity: The fork is the link. BIOARCHITECTURE 2014; 2:6-10. [PMID: 22754621 PMCID: PMC3383716 DOI: 10.4161/bioa.19737] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Maintaining the stability of the replication forks is one of the main tasks of the DNA damage response. Specifically, checkpoint mechanisms detect stressed forks and prevent their collapse. In the published report reviewed here we have shown that defective chromatin assembly in cells lacking either H3K56 acetylation or the chromatin assembly factors CAF1 and Rtt106 affects the integrity of advancing replication forks, despite the presence of functional checkpoints. This loss of replication intermediates is exacerbated in the absence of Rad52, suggesting that collapsed forks are rescued by homologous recombination and providing an explanation for the accumulation of recombinogenic DNA damage displayed by these mutants. These phenotypes mimic those obtained by a partial reduction in the pool of available histones and are consistent with a model in which defective histone deposition uncouples DNA synthesis and nucleosome assembly, thus making the fork more susceptible to collapse. Here, we review these findings and discuss the possibility that defects in the lagging strand represent a major source of fork instability in chromatin assembly mutants.
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Affiliation(s)
- Félix Prado
- Departamento de Biología Molecular; Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER); Consejo Superior de Investigaciones Científicas (CSIC); Seville, Spain
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Lin CY, Wu MY, Gay S, Marjavaara L, Lai MS, Hsiao WC, Hung SH, Tseng HY, Wright DE, Wang CY, Hsu GSW, Devys D, Chabes A, Kao CF. H2B mono-ubiquitylation facilitates fork stalling and recovery during replication stress by coordinating Rad53 activation and chromatin assembly. PLoS Genet 2014; 10:e1004667. [PMID: 25275495 PMCID: PMC4183429 DOI: 10.1371/journal.pgen.1004667] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Accepted: 08/14/2014] [Indexed: 01/11/2023] Open
Abstract
The influence of mono-ubiquitylation of histone H2B (H2Bub) on transcription via nucleosome reassembly has been widely documented. Recently, it has also been shown that H2Bub promotes recovery from replication stress; however, the underling molecular mechanism remains unclear. Here, we show that H2B ubiquitylation coordinates activation of the intra-S replication checkpoint and chromatin re-assembly, in order to limit fork progression and DNA damage in the presence of replication stress. In particular, we show that the absence of H2Bub affects replication dynamics (enhanced fork progression and reduced origin firing), leading to γH2A accumulation and increased hydroxyurea sensitivity. Further genetic analysis indicates a role for H2Bub in transducing Rad53 phosphorylation. Concomitantly, we found that a change in replication dynamics is not due to a change in dNTP level, but is mediated by reduced Rad53 activation and destabilization of the RecQ helicase Sgs1 at the fork. Furthermore, we demonstrate that H2Bub facilitates the dissociation of the histone chaperone Asf1 from Rad53, and nucleosome reassembly behind the fork is compromised in cells lacking H2Bub. Taken together, these results indicate that the regulation of H2B ubiquitylation is a key event in the maintenance of genome stability, through coordination of intra-S checkpoint activation, chromatin assembly and replication fork progression. Eukaryotic DNA is organized into nucleosomes, which are the fundamental repeating units of chromatin. Coordination of chromatin structure is required for efficient and accurate DNA replication. Aberrant DNA replication results in mutations and chromosome rearrangements that may be associated with human disorders. Therefore, cellular surveillance mechanisms have evolved to counteract potential threats to DNA replication. These mechanisms include checkpoints and specialized enzymatic activities that prevent the replication and segregation of defective DNA molecules. We employed a genome-wide approach to investigate how chromatin structure affects DNA replication under stress. We report that coordination of chromatin assembly and checkpoint activity by a histone modification, H2B ubiquitylation (H2Bub), is critical for the cell response to HU-induced replication stress. In cells with a mutation that abolishes H2Bub, replication progression is enhanced, and the forks are more susceptible to damage by environmental insults. The replication proteins on replicating DNA are akin to a train on the tracks, and movement of this train is carefully controlled. Our data indicate that H2Bub helps organize DNA in the nuclei during DNA replication; this process plays a similar role to the brakes on a train, serving to slow down replication, and maintaining stable progression of replication under environmental stress.
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Affiliation(s)
- Chia-Yeh Lin
- Institute of Cellular and Organismic Biology, Academia Sinica, Nankang, Taipei, Taiwan
- Graduate Institute of Nutrition and Food Sciences, Fu-Jen Catholic University, Xinzhuang, New Taipei City, Taiwan
| | - Meng-Ying Wu
- Institute of Cellular and Organismic Biology, Academia Sinica, Nankang, Taipei, Taiwan
| | - Sophie Gay
- Fondazione Istituto FIRC di Oncologia Molecolare (IFOM), IFOM-IEO Campus, Milan, Italy
| | - Lisette Marjavaara
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, Sweden
| | - Mong Sing Lai
- Fondazione Istituto FIRC di Oncologia Molecolare (IFOM), IFOM-IEO Campus, Milan, Italy
| | - Wei-Chun Hsiao
- Institute of Cellular and Organismic Biology, Academia Sinica, Nankang, Taipei, Taiwan
| | - Shih-Hsun Hung
- Institute of Cellular and Organismic Biology, Academia Sinica, Nankang, Taipei, Taiwan
| | - Hsin-Yi Tseng
- Institute of Cellular and Organismic Biology, Academia Sinica, Nankang, Taipei, Taiwan
| | - Duncan Edward Wright
- Institute of Cellular and Organismic Biology, Academia Sinica, Nankang, Taipei, Taiwan
| | - Chen-Yi Wang
- Institute of Cellular and Organismic Biology, Academia Sinica, Nankang, Taipei, Taiwan
- Institut de Génétique et de Biologie Moléculaire. CNRS UMR 7104, INSERM U 596, Université Louis Pasteur de Strasbourg, Illkirch, CU de Strasbourg, France
| | - Guoo-Shyng W. Hsu
- Graduate Institute of Nutrition and Food Sciences, Fu-Jen Catholic University, Xinzhuang, New Taipei City, Taiwan
| | - Didier Devys
- Institut de Génétique et de Biologie Moléculaire. CNRS UMR 7104, INSERM U 596, Université Louis Pasteur de Strasbourg, Illkirch, CU de Strasbourg, France
| | - Andrei Chabes
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, Sweden
| | - Cheng-Fu Kao
- Institute of Cellular and Organismic Biology, Academia Sinica, Nankang, Taipei, Taiwan
- * E-mail:
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Pamblanco M, Oliete-Calvo P, García-Oliver E, Luz Valero M, Sanchez del Pino MM, Rodríguez-Navarro S. Unveiling novel interactions of histone chaperone Asf1 linked to TREX-2 factors Sus1 and Thp1. Nucleus 2014; 5:247-59. [PMID: 24824343 DOI: 10.4161/nucl.29155] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Anti-silencing function 1 (Asf1) is a conserved key eukaryotic histone H3/H4 chaperone that participates in a variety of DNA and chromatin-related processes. These include the assembly and disassembly of histones H3 and H4 from chromatin during replication, transcription, and DNA repair. In addition, Asf1 is required for H3K56 acetylation activity dependent on histone acetyltransferase Rtt109. Thus, Asf1 impacts on many aspects of DNA metabolism. To gain insights into the functional links of Asf1 with other cellular machineries, we employed mass spectrometry coupled to tandem affinity purification (TAP) to investigate novel physical interactions of Asf1. Under different TAP-MS analysis conditions, we describe a new repertoire of Asf1 physical interactions and novel Asf1 post-translational modifications as ubiquitination, methylation and acetylation that open up new ways to regulate Asf1 functions. Asf1 co-purifies with several subunits of the TREX-2, SAGA complexes, and with nucleoporins Nup2, Nup60, and Nup57, which are all involved in transcription coupled to mRNA export in eukaryotes. Reciprocally, Thp1 and Sus1 interact with Asf1. Albeit mRNA export and GAL1 transcription are not affected in asf1Δ a strong genetic interaction exists between ASF1 and SUS1. Notably, supporting a functional link between Asf1 and TREX-2, both Sus1 and Thp1 affect the levels of Asf1-dependent histone H3K56 acetylation and histone H3 and H4 incorporation onto chromatin. Additionally, we provide evidence for a role of Asf1 in histone H2B ubiquitination. This work proposes a functional link between Asf1 and TREX-2 components in histone metabolism at the vicinity of the nuclear pore complex.
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Affiliation(s)
- Mercè Pamblanco
- Departament de Bioquímica i Biologia Molecular; Universitat de València; Burjassot, Spain
| | - Paula Oliete-Calvo
- Gene Expression and RNA Metabolism Laboratory; Centro de Investigación Príncipe Felipe (CIPF); València, Spain
| | - Encar García-Oliver
- Gene Expression and RNA Metabolism Laboratory; Centro de Investigación Príncipe Felipe (CIPF); València, Spain
| | - M Luz Valero
- Secció de Proteòmica; Servei Central de Suport a la Investigació Experimental (SCSIE); Universitat de València; Burjassot, Spain
| | | | - Susana Rodríguez-Navarro
- Gene Expression and RNA Metabolism Laboratory; Centro de Investigación Príncipe Felipe (CIPF); València, Spain
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Burgess RJ, Han J, Zhang Z. The Ddc1-Mec3-Rad17 sliding clamp regulates histone-histone chaperone interactions and DNA replication-coupled nucleosome assembly in budding yeast. J Biol Chem 2014; 289:10518-10529. [PMID: 24573675 DOI: 10.1074/jbc.m114.552463] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The maintenance of genome integrity is regulated in part by chromatin structure and factors involved in the DNA damage response pathway. Nucleosome assembly is a highly regulated process that restores chromatin structure after DNA replication, DNA repair, and gene transcription. During S phase the histone chaperones Asf1, CAF-1, and Rtt106 coordinate to deposit newly synthesized histones H3-H4 onto replicated DNA in budding yeast. Here we describe synthetic genetic interactions between RTT106 and the DDC1-MEC3-RAD17 (9-1-1) complex, a sliding clamp functioning in the S phase DNA damage and replication checkpoint response, upon treatment with DNA damaging agents. The DNA damage sensitivity of rad17Δ rtt106Δ cells depends on the function of Rtt106 in nucleosome assembly. Epistasis analysis reveals that 9-1-1 complex components interact with multiple DNA replication-coupled nucleosome assembly factors, including Rtt106, CAF-1, and lysine residues of H3-H4. Furthermore, rad17Δ cells exhibit defects in the deposition of newly synthesized H3-H4 onto replicated DNA. Finally, deletion of RAD17 results in increased association of Asf1 with checkpoint kinase Rad53, which may lead to the observed reduction in Asf1-H3 interaction in rad17Δ mutant cells. In addition, we observed that the interaction between histone H3-H4 with histone chaperone CAF-1 or Rtt106 increases in cells lacking Rad17. These results support the idea that the 9-1-1 checkpoint protein regulates DNA replication-coupled nucleosome assembly in part through regulating histone-histone chaperone interactions.
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Affiliation(s)
- Rebecca J Burgess
- Department of Biochemistry and Molecular Biology, Epigenomics Translational Program, Center for Individualized Medicine, Mayo Clinic College of Medicine, Rochester, Minnesota 55905
| | - Junhong Han
- Department of Biochemistry and Molecular Biology, Epigenomics Translational Program, Center for Individualized Medicine, Mayo Clinic College of Medicine, Rochester, Minnesota 55905
| | - Zhiguo Zhang
- Department of Biochemistry and Molecular Biology, Epigenomics Translational Program, Center for Individualized Medicine, Mayo Clinic College of Medicine, Rochester, Minnesota 55905.
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Im JS, Keaton M, Lee KY, Kumar P, Park J, Dutta A. ATR checkpoint kinase and CRL1βTRCP collaborate to degrade ASF1a and thus repress genes overlapping with clusters of stalled replication forks. Genes Dev 2014; 28:875-87. [PMID: 24700029 PMCID: PMC4003279 DOI: 10.1101/gad.239194.114] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Many chemotherapeutic agents, such as doxorubicin (DOX), interfere with DNA replication. Here, Dutta and colleagues show that DOX treatment produces clusters of stalled replication forks and transcriptional repression of neighboring genes. An ATR-dependent checkpoint pathway that down-regulates histone chaperone ASF1a is shown to repress genes overlapping with stalled replication forks. Furthermore, ASF1a-depleted cancer cells are more sensitive to DOX, suggesting that the loss of this histone chaperone, as seen in several cancers, could be a personalized tumor marker for sensitivity to DOX. Many agents used for chemotherapy, such as doxorubicin, interfere with DNA replication, but the effect of this interference on transcription is largely unknown. Here we show that doxorubicin induces the firing of dense clusters of neoreplication origins that lead to clusters of stalled replication forks in gene-rich parts of the genome, particularly on expressed genes. Genes that overlap with these clusters of stalled forks are actively dechromatinized, unwound, and repressed by an ATR-dependent checkpoint pathway. The ATR checkpoint pathway causes a histone chaperone normally associated with the replication fork, ASF1a, to degrade through a CRL1βTRCP-dependent ubiquitination/proteasome pathway, leading to the localized dechromatinization and gene repression. Therefore, a globally active checkpoint pathway interacts with local clusters of stalled forks to specifically repress genes in the vicinity of the stalled forks, providing a new mechanism of action of chemotherapy drugs like doxorubicin. Finally, ASF1a-depleted cancer cells are more sensitive to doxorubicin, suggesting that the 7%–10% of prostate adenocarcinomas and adenoid cystic carcinomas reported to have homozygous deletion or significant underexpression of ASF1a should be tested for high sensitivity to doxorubicin.
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Affiliation(s)
- Jun-Sub Im
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, Virginia 22908, USA
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18
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Pascoalino B, Dindar G, Vieira-da-Rocha JP, Machado CR, Janzen CJ, Schenkman S. Characterization of two different Asf1 histone chaperones with distinct cellular localizations and functions in Trypanosoma brucei. Nucleic Acids Res 2013; 42:2906-18. [PMID: 24322299 PMCID: PMC3950673 DOI: 10.1093/nar/gkt1267] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The anti-silencing function protein 1 (Asf1) is a chaperone that forms a complex with histones H3 and H4 facilitating dimer deposition and removal from chromatin. Most eukaryotes possess two different Asf1 chaperones but their specific functions are still unknown. Trypanosomes, a group of early-diverged eukaryotes, also have two, but more divergent Asf1 paralogs than Asf1 of higher eukaryotes. To unravel possible different functions, we characterized the two Asf1 proteins in Trypanosoma brucei. Asf1A is mainly localized in the cytosol but translocates to the nucleus in S phase. In contrast, Asf1B is predominantly localized in the nucleus, as described for other organisms. Cytosolic Asf1 knockdown results in accumulation of cells in early S phase of the cell cycle, whereas nuclear Asf1 knockdown arrests cells in S/G2 phase. Overexpression of cytosolic Asf1 increases the levels of histone H3 and H4 acetylation. In contrast to cytosolic Asf1, overexpression of nuclear Asf1 causes less pronounced growth defects in parasites exposed to genotoxic agents, prompting a function in chromatin remodeling in response to DNA damage. Only the cytosolic Asf1 interacts with recombinant H3/H4 dimers in vitro. These findings denote the early appearance in evolution of distinguishable functions for the two Asf1 chaperons in trypanosomes.
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Affiliation(s)
- Bruno Pascoalino
- Depto. de Microbiologia, Imunologia e Parasitologia, UNIFESP, Rua Pedro de Toledo 669 L6A, São Paulo, São Paulo 04039-032, Brazil, Lehrstuhl für Zell- und Entwicklungsbiologie, Theodor-Boveri-Institut, Biozentrum der Universität Würzburg, Am Hubland, 97074 Würzburg, Germany and Depto. de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, CP 4861, 30161-970, Belo Horizonte, Minas Gerais, Brazil
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19
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Garg J, Lambert JP, Karsou A, Marquez S, Nabeel-Shah S, Bertucci V, Retnasothie DV, Radovani E, Pawson T, Gingras AC, Pearlman RE, Fillingham JS. Conserved Asf1-importin β physical interaction in growth and sexual development in the ciliate Tetrahymena thermophila. J Proteomics 2013; 94:311-26. [PMID: 24120531 DOI: 10.1016/j.jprot.2013.09.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Revised: 09/07/2013] [Accepted: 09/23/2013] [Indexed: 01/14/2023]
Abstract
UNLABELLED How the eukaryotic cell specifies distinct chromatin domains is a central problem in molecular biology. The ciliate protozoan Tetrahymena thermophila features a separation of structurally and functionally distinct germ-line and somatic chromatin into two distinct nuclei, the micronucleus (MIC) and macronucleus (MAC) respectively. To address questions about how distinct chromatin states are assembled in the MAC and MIC, we have initiated studies to define protein-protein interactions for T. thermophila chromatin-related proteins. Affinity purification followed by mass spectrometry analysis of the conserved Asf1 histone chaperone in T. thermophila revealed that it forms a complex with an importin β, ImpB6. Furthermore, these proteins co-localized to both the MAC and MIC in growth and development. We suggest that newly synthesized histones H3 and H4 in T. thermophila are transported via Asf1-ImpB6 in an evolutionarily conserved pathway to both nuclei where they then enter nucleus-specific chromatin assembly pathways. These studies set the stage for further use of functional proteomics to elucidate details of the characterization and functional analysis of the unique chromatin domains in T. thermophila. BIOLOGICAL SIGNIFICANCE Asf1 is an evolutionarily conserved chaperone of H3 and H4 histones that functions in replication dependent and independent chromatin assembly. Although Asf1 has been well studied in humans and yeast (members of the Opisthokonta lineage of eukaryotes), questions remain concerning its mechanism of function. To obtain additional insight into the Asf1 function we have initiated a proteomic analysis in the ciliate protozoan T. thermophila, a member of the Alveolata lineage of eukaryotes. Our results suggest that an evolutionarily conserved function of Asf1 is mediating the nuclear transport of newly synthesized histones H3 and H4.
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Affiliation(s)
- Jyoti Garg
- Department of Biology, York University, 4700 Keele St., Toronto M3J 1P3, Canada
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Lopez MF, Tollervey J, Krastins B, Garces A, Sarracino D, Prakash A, Vogelsang M, Geesman G, Valderrama A, Jordan IK, Lunyak VV. Depletion of nuclear histone H2A variants is associated with chronic DNA damage signaling upon drug-evoked senescence of human somatic cells. Aging (Albany NY) 2013; 4:823-42. [PMID: 23235539 PMCID: PMC3560435 DOI: 10.18632/aging.100507] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Cellular senescence is associated with global chromatin changes, altered gene expression, and activation of chronic DNA damage signaling. These events ultimately lead to morphological and physiological transformations in primary cells. In this study, we show that chronic DNA damage signals caused by genotoxic stress impact the expression of histones H2A family members and lead to their depletion in the nuclei of senescent human fibroblasts. Our data reinforce the hypothesis that progressive chromatin destabilization may lead to the loss of epigenetic information and impaired cellular function associated with chronic DNA damage upon drug-evoked senescence. We propose that changes in the histone biosynthesis and chromatin assembly may directly contribute to cellular aging. In addition, we also outline the method that allows for quantitative and unbiased measurement of these changes.
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Affiliation(s)
- Mary F Lopez
- BRIMS, Thermo Fisher Scientific, Cambridge, MA, USA
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21
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Characterization of the Pneumocystis carinii histone acetyltransferase chaperone proteins PcAsf1 and PcVps75. Infect Immun 2013; 81:2268-75. [PMID: 23569117 DOI: 10.1128/iai.01173-12] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Rtt109 is a lysine acetyltransferase that acetylates histone H3 at lysine 56 (H3K56) in fungi. This acetylation event is important for proper DNA replication and repair to occur. Efficient Rtt109 acetyltransferase activity also requires a histone chaperone, vacuolar protein sorting 75 (Vps75), as well as the major chaperone of the H3-H4 dimer, anti-silencing factor 1 (Asf1). Little is known about the role of these proteins in the opportunistic fungal pathogen Pneumocystis carinii. To investigate the functions of Asf1 and Vps75 in Pneumocystis carinii, we cloned and characterized both of these genes. Here, we demonstrate that both genes, P. carinii asf1 (Pcasf1) and Pcvps75, function in a fashion analogous to their Saccharomyces cerevisiae counterparts. We demonstrate that both P. carinii Asf1 (PcAsf1) and PcVps75 can bind histones. Furthermore, when Pcasf1 is expressed heterologously in S. cerevisiae asf1Δ cells, PcAsf1 can restore full H3 lysine acetylation. We further demonstrated that the Pcasf1 cDNA expressed in asf1Δ S. cerevisiae cells can restore growth to wild-type levels in the presence of genotoxic agents that block DNA replication. Lastly, we observed that purified PcAsf1 and PcVps75 proteins enhance the ability of PcRtt109 to acetylate histone H3-H4 tetramers. Together, our results indicate that the functions of the Rtt109-Asf1-Vps75 complex in the acetylation of histone H3 lysine 56 and in DNA damage response are present in P. carinii DNA and cell cycle progression.
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Histone H3K56 acetylation, Rad52, and non-DNA repair factors control double-strand break repair choice with the sister chromatid. PLoS Genet 2013; 9:e1003237. [PMID: 23357952 PMCID: PMC3554610 DOI: 10.1371/journal.pgen.1003237] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Accepted: 11/27/2012] [Indexed: 11/20/2022] Open
Abstract
DNA double-strand breaks (DSBs) are harmful lesions that arise mainly during replication. The choice of the sister chromatid as the preferential repair template is critical for genome integrity, but the mechanisms that guarantee this choice are unknown. Here we identify new genes with a specific role in assuring the sister chromatid as the preferred repair template. Physical analyses of sister chromatid recombination (SCR) in 28 selected mutants that increase Rad52 foci and inter-homolog recombination uncovered 8 new genes required for SCR. These include the SUMO/Ub-SUMO protease Wss1, the stress-response proteins Bud27 and Pdr10, the ADA histone acetyl-transferase complex proteins Ahc1 and Ada2, as well as the Hst3 and Hst4 histone deacetylase and the Rtt109 histone acetyl-transferase genes, whose target is histone H3 Lysine 56 (H3K56). Importantly, we use mutations in H3K56 residue to A, R, and Q to reveal that H3K56 acetylation/deacetylation is critical to promote SCR as the major repair mechanism for replication-born DSBs. The same phenotype is observed for a particular class of rad52 alleles, represented by rad52-C180A, with a DSB repair defect but a spontaneous hyper-recombination phenotype. We propose that specific Rad52 residues, as well as the histone H3 acetylation/deacetylation state of chromatin and other specific factors, play an important role in identifying the sister as the choice template for the repair of replication-born DSBs. Our work demonstrates the existence of specific functions to guarantee SCR as the main repair event for replication-born DSBs that can occur by two pathways, one Rad51-dependent and the other Pol32-dependent. A dysfunction can lead to genome instability as manifested by high levels of homolog recombination and DSB accumulation. Double-strand breaks (DSBs) are among the most dangerous DNA lesions and can lead to genomic instability, a process associated with cancer and hereditary diseases. An important source of DSBs is replication, Sister Chromatid Recombination (SCR) being the main mechanism for DSB repair in dividing eukaryotic cells. SCR repair is error-free and uses the sister chromatid as template, generating an identical DNA sequence and therefore preventing genomic instability. In this work, we use an inverted-repeat assay with which we can physically detect SCR intermediates generated by the repair of a replication-born DSB. We hypothesized that SCR defects can result in an increase of recombination with the homologous chromosome, so we assayed SCR in 28 mutants previously described to increase homolog recombination. Our results describe 8 new genes involved in SCR, including functions such as histone acetylation/deacetylation, SUMO-Ubiquitin metabolism, and stress response, as well as an allele of RAD52. This demonstrates the importance of the choice of the sister chromatid as template for DSB repair and provides a broad vision of SCR as a tightly regulated process essential for genome integrity.
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The C terminus of the histone chaperone Asf1 cross-links to histone H3 in yeast and promotes interaction with histones H3 and H4. Mol Cell Biol 2012. [PMID: 23184661 DOI: 10.1128/mcb.01053-12] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The central histone H3/H4 chaperone Asf1 comprises a highly conserved globular core and a divergent C-terminal tail. While the function and structure of the Asf1 core are well known, the function of the tail is less well understood. Here, we have explored the role of the yeast (yAsf1) and human (hAsf1a and hAsf1b) Asf1 tails in Saccharomyces cerevisiae. We show, using a photoreactive, unnatural amino acid, that Asf1 tail residue 210 cross-links to histone H3 in vivo and, further, that loss of C-terminal tail residues 211 to 279 weakens yAsf1-histone binding affinity in vitro nearly 200-fold. Via several yAsf1 C-terminal truncations and yeast-human chimeric proteins, we found that truncations at residue 210 increase transcriptional silencing and that the hAsf1a tail partially substitutes for full-length yAsf1 with respect to silencing but that full-length hAsf1b is a better overall substitute for full-length yAsf1. In addition, we show that the C-terminal tail of Asf1 is phosphorylated at T270 in yeast. Loss of this phosphorylation site does not prevent coimmunoprecipitation of yAsf1 and Rad53 from yeast extracts, whereas amino acid residue substitutions at the Asf1-histone H3/H4 interface do. Finally, we show that residue substitutions in yAsf1 near the CAF-1/HIRA interface also influence yAsf1's function in silencing.
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Chromatin assembly on herpes simplex virus 1 DNA early during a lytic infection is Asf1a dependent. J Virol 2012; 86:12313-21. [PMID: 22951827 DOI: 10.1128/jvi.01570-12] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Herpes simplex virus (HSV) is a large DNA virus which is characterized by its ability to form latent infections in neurons of the peripheral nervous system. Although histones are found in the capsids of small DNA viruses (papovaviruses), none are found in the capsids of large HSV. However, after entry into the infected cell nucleus, the HSV genome begins to associate with nucleosomes during the earliest stages of infection. In contrast, late during infection, newly replicated viral DNA does not appear to associate with nucleosomes, suggesting that histones are deposited specifically on input viral DNA. The mechanisms of deposition and removing histones from the viral genome are unclear. Recently, histone chaperones, involved in the assembly and disassembly of nucleosomes, have been identified. Human antisilencing factor 1 (Asf1) is one such factor which is involved in both the assembly and disassembly of nucleosomes in cellular systems. In this study, we have examined the effect of small interfering RNA (siRNA) knockdown of Asf1a on HSV infections in HeLa cells. Both viral replication and growth were found to be decreased. Also, viral DNA was significantly less protected from micrococcal nuclease (MNase) digestion up to 6 h postinfection (hpi). However, transcription of the immediate early (IE) genes ICP0 and ICP4 was significantly upregulated at 3 h postinfection. Also, these genes were found to be less protected from MNase digestion and, therefore, less associated with nucleosomes. These results suggest that Asf1a plays a role in regulating IE genes by assembling chromatin onto histone-free viral DNA by 3 h postinfection.
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Scher R, Garcia JBF, Pascoalino B, Schenkman S, Cruz AK. Characterization of anti-silencing factor 1 in Leishmania major. Mem Inst Oswaldo Cruz 2012; 107:377-86. [DOI: 10.1590/s0074-02762012000300013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Accepted: 01/11/2012] [Indexed: 02/19/2023] Open
Affiliation(s)
- Ricardo Scher
- Universidade de São Paulo, Brasil; Universidade Federal de Sergipe, Brasil
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Surprising complexity of the Asf1 histone chaperone-Rad53 kinase interaction. Proc Natl Acad Sci U S A 2012; 109:2866-71. [PMID: 22323608 DOI: 10.1073/pnas.1106023109] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The histone chaperone Asf1 and the checkpoint kinase Rad53 are found in a complex in budding yeast cells in the absence of genotoxic stress. Our data suggest that this complex involves at least three interaction sites. One site involves the H3-binding surface of Asf11 with an as yet undefined surface of Rad53. A second site is formed by the Rad53-FHA1 domain binding to Asf1-T(270) phosphorylated by casein kinase II. The third site involves the C-terminal 21 amino acids of Rad53 bound to the conserved Asf1 N-terminal domain. The structure of this site showed that the Rad53 C-terminus binds Asf1 in a remarkably similar manner to peptides derived from the histone cochaperones HirA and CAF-I. We call this binding motif, (R/K)R(I/A/V) (L/P), the AIP box for Asf1-Interacting Protein box. Furthermore, C-terminal Rad53-F(820) binds the same pocket of Asf1 as does histone H4-F(100). Thus Rad53 competes with histones H3-H4 and cochaperones HirA/CAF-I for binding to Asf1. Rad53 is phosphorylated and activated upon genotoxic stress. The Asf1-Rad53 complex dissociated when cells were treated with hydroxyurea but not methyl-methane-sulfonate, suggesting a regulation of the complex as a function of the stress. We identified a rad53 mutation that destabilized the Asf1-Rad53 complex and increased the viability of rad9 and rad24 mutants in conditions of genotoxic stress, suggesting that complex stability impacts the DNA damage response.
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Grandin N, Bailly A, Charbonneau M. Activation of Mrc1, a mediator of the replication checkpoint, by telomere erosion. Biol Cell 2012; 97:799-814. [PMID: 15760303 DOI: 10.1042/bc20040526] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND INFORMATION In budding yeast, the loss of either telomere sequences (in telomerase-negative cells) or telomere capping (in mutants of two telomere end-protection proteins, Cdc13 and Yku) lead, by distinct pathways, to telomeric senescence. After DNA damage, activation of Rad53, which together with Chk1 represents a protein kinase central to all checkpoint pathways, normally requires Rad9, a checkpoint adaptor. RESULTS We report that in telomerase-negative (tlc1Delta) cells, activation of Rad53, although diminished, could still take place in the absence of Rad9. In contrast, Rad9 was essential for Rad53 activation in cells that entered senescence in the presence of functional telomerase, namely in senescent cells bearing mutations in telomere end-protection proteins (cdc13-1 yku70Delta). In telomerase-negative cells deleted for RAD9, Mrc1, another checkpoint adaptor previously implicated in the DNA replication checkpoint, mediated Rad53 activation. Rad9 and Rad53, as well as other DNA damage checkpoint proteins (Mec1, Mec3, Chk1 and Dun1), were required for complete DNA-damage-induced cell-cycle arrest after loss of telomerase function. However, unexpectedly, given the formation of an active Rad53-Mrc1 complex in tlc1Delta rad9Delta cells, Mrc1 did not mediate the cell-cycle arrest elicited by telomerase loss. Finally, we report that Rad9, Mrc1, Dun1 and Chk1 are activated by phosphorylation after telomerase inactivation. CONCLUSIONS These results indicate that loss of telomere capping and loss of telomere sequences, both of which provoke telomeric senescence, are perceived as two distinct types of damages. In contrast with the Rad53-Rad9-mediated cell-cycle arrest that functions in a similar way in both types of telomeric senescence, activation of Rad53-Mrc1 might represent a specific response to telomerase inactivation and/or telomere shortening, the functional significance of which has yet to be uncovered.
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Affiliation(s)
- Nathalie Grandin
- IFR128 BioSciences Gerland, UMR CNRS no. 5161, Ecole Normale Supérieure de Lyon, 46 allée d'Italie, 69364 Lyon, France
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Inositol phosphate kinase Vip1p interacts with histone chaperone Asf1p in Saccharomyces cerevisiae. Mol Biol Rep 2011; 39:4989-96. [PMID: 22160571 DOI: 10.1007/s11033-011-1295-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2011] [Accepted: 11/30/2011] [Indexed: 12/25/2022]
Abstract
Histone eviction and deposition are critical steps in many nuclear processes. The histone H3/H4 chaperone Asf1p is highly conserved and is involved in DNA replication, DNA repair, and transcription. To identify the factors concerned with anti-silencing function 1 (ASF1), we purified Asf1p-associated factors from the yeast Saccharomyces cerevisiae by a GST pull-down experiment, and mass spectrometry analysis was performed. Several factors are specifically associated with Asf1p, including Vip1p. VIP1 is conserved from yeast to humans and encodes inositol hexakisphoshate and inositol heptakisphosphate kinase. Vip1p interacted with Asf1p as a dimer or in a complex with another protein(s). Deletion of VIP1 did not affect the interaction between Asf1p and other Asf1p-associated factors. An in vitro GST pull-down assay indicated a direct interaction between Asf1p and Vip1p, and the interaction between the two factors in vivo was detected by an immunoprecipitation experiment. Furthermore, genetic experiments revealed that VIP1 disruption increased sensitivity to 6-azauracil (6-AU), but not to DNA-damaging reagents in wild-type and ASF1-deleted strains. It is thought that 6-AU decreases nucleotide levels and reduces transcription elongation. These observations suggest that the association of Asf1p and Vip1p may be implicated in transcription elongation.
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Clemente-Ruiz M, González-Prieto R, Prado F. Histone H3K56 acetylation, CAF1, and Rtt106 coordinate nucleosome assembly and stability of advancing replication forks. PLoS Genet 2011; 7:e1002376. [PMID: 22102830 PMCID: PMC3213180 DOI: 10.1371/journal.pgen.1002376] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Accepted: 09/23/2011] [Indexed: 12/26/2022] Open
Abstract
Chromatin assembly mutants accumulate recombinogenic DNA damage and are sensitive to genotoxic agents. Here we have analyzed why impairment of the H3K56 acetylation-dependent CAF1 and Rtt106 chromatin assembly pathways, which have redundant roles in H3/H4 deposition during DNA replication, leads to genetic instability. We show that the absence of H3K56 acetylation or the simultaneous knock out of CAF1 and Rtt106 increases homologous recombination by affecting the integrity of advancing replication forks, while they have a minor effect on stalled replication fork stability in response to the replication inhibitor hydroxyurea. This defect in replication fork integrity is not due to defective checkpoints. In contrast, H3K56 acetylation protects against replicative DNA damaging agents by DNA repair/tolerance mechanisms that do not require CAF1/Rtt106 and are likely subsequent to the process of replication-coupled nucleosome deposition. We propose that the tight connection between DNA synthesis and histone deposition during DNA replication mediated by H3K56ac/CAF1/Rtt106 provides a mechanism for the stabilization of advancing replication forks and the maintenance of genome integrity, while H3K56 acetylation has an additional, CAF1/Rtt106-independent function in the response to replicative DNA damage. Loss of replication fork integrity is a primary source of genetic instability. In eukaryotes DNA synthesis is rapidly followed by its assembly into chromatin, and these two processes are tightly connected. Defective chromatin assembly mutants accumulate DNA damage and are sensitive to genotoxic agents, even though the mechanisms responsible for this genetic instability remain unclear because chromatin assembly also plays essential roles in transcription, silencing, DNA repair, and checkpoint signaling. A good example is the acetylation of histone H3 at lysine 56, which promotes histone deposition by the chromatin assembly factors CAF1 and Rtt106. In this case, the absence of this modification also causes a loss of structural and/or coding information at chromatin. Here we show that defective replication-coupled chromatin assembly leads to an accumulation of recombinogenic DNA damage by affecting the integrity of advancing, but not stalled, replication forks. Therefore, we propose that H3K56ac/CAF1/Rtt106-dependent chromatin assembly provides a mechanism for the stabilization of replication forks. Besides, H3K56 acetylation promotes replicative DNA damage repair/tolerance through a function that is independent of CAF1/Rtt106 and likely subsequent to its deposition at chromatin, revealing this modification as a key regulator of genome integrity.
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Affiliation(s)
- Marta Clemente-Ruiz
- Departamento de Biología Molecular, Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Consejo Superior de Investigaciones Científicas (CSIC), Seville, Spain
| | - Román González-Prieto
- Departamento de Biología Molecular, Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Consejo Superior de Investigaciones Científicas (CSIC), Seville, Spain
| | - Félix Prado
- Departamento de Biología Molecular, Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Consejo Superior de Investigaciones Científicas (CSIC), Seville, Spain
- * E-mail:
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Sims JK, Wade PA. Mi-2/NuRD complex function is required for normal S phase progression and assembly of pericentric heterochromatin. Mol Biol Cell 2011; 22:3094-102. [PMID: 21737684 PMCID: PMC3164457 DOI: 10.1091/mbc.e11-03-0258] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
During chromosome duplication, it is essential to replicate not only the DNA sequence, but also the complex nucleoprotein structures of chromatin. Pericentric heterochromatin is critical for silencing repetitive elements and plays an essential structural role during mitosis. However, relatively little is understood about its assembly and maintenance during replication. The Mi2/NuRD chromatin remodeling complex tightly associates with actively replicating pericentric heterochromatin, suggesting a role in its assembly. Here we demonstrate that depletion of the catalytic ATPase subunit CHD4/Mi-2β in cells with a dampened DNA damage response results in a slow-growth phenotype characterized by delayed progression through S phase. Furthermore, we observe defects in pericentric heterochromatin maintenance and assembly. Our data suggest that chromatin assembly defects are sensed by an ATM-dependent intra-S phase chromatin quality checkpoint, resulting in a temporal block to the transition from early to late S phase. These findings implicate Mi-2β in the maintenance of chromatin structure and proper cell cycle progression.
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Affiliation(s)
- Jennifer K Sims
- Laboratory of Molecular Carcinogenesis, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
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Battu A, Ray A, Wani AA. ASF1A and ATM regulate H3K56-mediated cell-cycle checkpoint recovery in response to UV irradiation. Nucleic Acids Res 2011; 39:7931-45. [PMID: 21727091 PMCID: PMC3185425 DOI: 10.1093/nar/gkr523] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Successful DNA repair within chromatin requires coordinated interplay of histone modifications, chaperones and remodelers for allowing access of repair and checkpoint machineries to damaged sites. Upon completion of repair, ordered restoration of chromatin structure and key epigenetic marks herald the cell's normal function. Here, we demonstrate such a restoration role of H3K56 acetylation (H3K56Ac) mark in response to ultraviolet (UV) irradiation of human cells. A fast initial deacetylation of H3K56 is followed by full renewal of an acetylated state at ~24-48 h post-irradiation. Histone chaperone, anti-silencing function-1 A (ASF1A), is crucial for post-repair H3K56Ac restoration, which in turn, is needed for the dephosphorylation of γ-H2AX and cellular recovery from checkpoint arrest. On the other hand, completion of DNA damage repair is not dependent on ASF1A or H3K56Ac. H3K56Ac restoration is regulated by ataxia telangiectasia mutated (ATM) checkpoint kinase. These cross-talking molecular cellular events reveal the important pathway components influencing the regulatory function of H3K56Ac in the recovery from UV-induced checkpoint arrest.
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Affiliation(s)
- Aruna Battu
- Department of Radiology, The Ohio State University, Columbus, OH 43210, USA
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Minard LV, Lin LJ, Schultz MC. SWI/SNF and Asf1 independently promote derepression of the DNA damage response genes under conditions of replication stress. PLoS One 2011; 6:e21633. [PMID: 21738741 PMCID: PMC3124541 DOI: 10.1371/journal.pone.0021633] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2011] [Accepted: 06/03/2011] [Indexed: 12/19/2022] Open
Abstract
The histone chaperone Asf1 and the chromatin remodeler SWI/SNF have been separately implicated in derepression of the DNA damage response (DDR) genes in yeast cells treated with genotoxins that cause replication interference. Using genetic and biochemical approaches, we have tested if derepression of the DDR genes in budding yeast involves functional interplay between Asf1 and SWI/SNF. We find that Asf1 and SWI/SNF are both recruited to DDR genes under replication stress triggered by hydroxyurea, and have detected a soluble complex that contains Asf1 and the Snf2 subunit of SWI/SNF. SWI/SNF recruitment to DDR genes however does not require Asf1, and deletion of Snf2 does not affect Asf1 occupancy of DDR gene promoters. A checkpoint engagement defect is sufficient to explain the synthetic effect of deletion of ASF1 and SNF2 on derepression of the DDR genes in hydroxyurea-treated cells. Collectively, our results show that the DDR genes fall into a class in which Asf1 and SWI/SNF independently control transcriptional induction.
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Affiliation(s)
- Laura V. Minard
- Department of Biochemistry, School of Molecular and Systems Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Ling-ju Lin
- Department of Biochemistry, School of Molecular and Systems Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Michael C. Schultz
- Department of Biochemistry, School of Molecular and Systems Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
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Lambert JP, Fillingham J, Siahbazi M, Greenblatt J, Baetz K, Figeys D. Defining the budding yeast chromatin-associated interactome. Mol Syst Biol 2011; 6:448. [PMID: 21179020 PMCID: PMC3018163 DOI: 10.1038/msb.2010.104] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Accepted: 11/05/2010] [Indexed: 11/09/2022] Open
Abstract
We previously reported a novel affinity purification (AP) method termed modified chromatin immunopurification (mChIP), which permits selective enrichment of DNA-bound proteins along with their associated protein network. In this study, we report a large-scale study of the protein network of 102 chromatin-related proteins from budding yeast that were analyzed by mChIP coupled to mass spectrometry. This effort resulted in the detection of 2966 high confidence protein associations with 724 distinct preys. mChIP resulted in significantly improved interaction coverage as compared with classical AP methodology for ∼75% of the baits tested. Furthermore, mChIP successfully identified novel binding partners for many lower abundance transcription factors that previously failed using conventional AP methodologies. mChIP was also used to perform targeted studies, particularly of Asf1 and its associated proteins, to allow for a understanding of the physical interplay between Asf1 and two other histone chaperones, Rtt106 and the HIR complex, to be gained.
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Affiliation(s)
- Jean-Philippe Lambert
- Department of Biochemistry, Microbiology and Immunology, Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, Ontario, Canada
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Sato L, Noguchi S, Hayashi Y, Sakamoto M, Horikoshi M. Global analysis of functional relationships between histone point mutations and the effects of histone deacetylase inhibitors. Genes Cells 2010; 15:553-94. [PMID: 20553507 DOI: 10.1111/j.1365-2443.2010.01408.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Comprehensive analyses of the histone-GLibrary in previous studies showed that most mutants of modification sites in the histone core regions show phenotypes, whereas those with modifications in the histone N-terminal unstructured tail regions (N-tails) do not. One possible reason is that modifications in N-tails are linked to each other to form a scale-free network termed histone 'modification web'. In the network, the compensatory pathways are created to acquire the robustness against the any defects. Because of this robustness, it is difficult to determine the significance of the individual histone modifications in N-tails in vivo. To overcome this problem, we used a strategy using drugs coordinately to inhibit modification enzymes and observed the mutant phenotypes when the compensatory pathways are largely interrupted. We analyzed histone-GLibrary using inhibitors of histone deacetylases (HDACs) and identified novel phenotypic mutants. We also examined the phenotypic changes through the combined use of an HDAC inhibitor and an inhibitor of DNA-mediated reactions. Mutation of modifiable sites H3-K4 and H4-K16 in histone N-tails, which are presumed to be the 'hubs' of the network, resulted in identifiable phenotypes. The data obtained provide valuable information for speculation on novel relationships between histone modification in N-tails and biological function and for predicting unknown modification sites in core histones.
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Affiliation(s)
- Lui Sato
- Laboratory of Developmental Biology, Institute of Molecular and Cellular Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
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Burgess RJ, Zhang Z. Roles for Gcn5 in promoting nucleosome assembly and maintaining genome integrity. Cell Cycle 2010; 9:2979-85. [PMID: 20699646 DOI: 10.4161/cc.9.15.12498] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The process of coordinated DNA replication and nucleosome assembly, termed replication-coupled (RC) nucleosome assembly, is important for the maintenance of genome integrity. Loss of genome integrity is linked to aging and cancer. RC nucleosome assembly involves deposition of histone H3-H4 by the histone chaperones CAF-1, Rtt106 and Asf1 onto newly-replicated DNA. Coordinated actions of these three histone chaperones are regulated by modifications on the histone proteins. One such modification is histone H3 lysine 56 acetylation (H3K56Ac), a mark of newly-synthesized histone H3 that regulates the interaction between H3-H4 and the histone chaperones CAF-1 and Rtt106 following DNA replication and DNA repair. Recently, we have shown that the lysine acetyltransferase Gcn5 and H3 N-terminal tail lysine acetylation also regulates the interaction between H3-H4 and CAF-1 to promote the deposition of newly-synthesized histones. Genetic studies indicate that Gcn5 and Rtt109, the H3K56Ac lysine acetyltransferase, function in parallel to maintain genome stability. Utilizing synthetic genetic array analysis, we set out to identify additional genes that function in parallel with Gcn5 in response to DNA damage. We summarize here the role of Gcn5 in nucleosome assembly and suggest that Gcn5 impacts genome integrity via multiple mechanisms, including nucleosome assembly.
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Affiliation(s)
- Rebecca J Burgess
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN, USA
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Akai Y, Adachi N, Hayashi Y, Eitoku M, Sano N, Natsume R, Kudo N, Tanokura M, Senda T, Horikoshi M. Structure of the histone chaperone CIA/ASF1-double bromodomain complex linking histone modifications and site-specific histone eviction. Proc Natl Acad Sci U S A 2010; 107:8153-8. [PMID: 20393127 PMCID: PMC2889523 DOI: 10.1073/pnas.0912509107] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Nucleosomes around the promoter region are disassembled for transcription in response to various signals, such as acetylation and methylation of histones. Although the interactions between histone-acetylation-recognizing bromodomains and factors involved in nucleosome disassembly have been reported, no structural basis connecting histone modifications and nucleosome disassembly has been obtained. Here, we determined at 3.3 A resolution the crystal structure of histone chaperone cell cycle gene 1 (CCG1) interacting factor A/antisilencing function 1 (CIA/ASF1) in complex with the double bromodomain in the CCG1/TAF1/TAF(II)250 subunit of transcription factor IID. Structural, biochemical, and biological studies suggested that interaction between double bromodomain and CIA/ASF1 is required for their colocalization, histone eviction, and pol II entry at active promoter regions. Furthermore, the present crystal structure has characteristics that can connect histone acetylation and CIA/ASF1-mediated histone eviction. These findings suggest that the molecular complex between CIA/ASF1 and the double bromodomain plays a key role in site-specific histone eviction at active promoter regions. The model we propose here is the initial structure-based model of the biological signaling from histone modifications to structural change of the nucleosome (hi-MOST model).
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Affiliation(s)
- Yusuke Akai
- Biomedicinal Information Research Center, National Institute of Advanced Industrial Science and Technology, 2-4-7 Aomi, Koto-ku, Tokyo 135-0064, Japan
- Protein Structural Information Analysis Team, Japan Biological Informatics Consortium, 2-4-7 Aomi, Koto-ku, Tokyo 135-0064, Japan
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Naruhiko Adachi
- Protein Structural Information Analysis Team, Japan Biological Informatics Consortium, 2-4-7 Aomi, Koto-ku, Tokyo 135-0064, Japan
- Laboratory of Developmental Biology, Institute of Molecular and Cellular Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan; and
- Horikoshi Gene Selector Project, Exploratory Research for Advanced Technology, Japan Science and Technology Agency, 5-9-6 Tokodai, Tsukuba, Ibaraki 300-2635, Japan
| | - Yohei Hayashi
- Laboratory of Developmental Biology, Institute of Molecular and Cellular Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan; and
| | - Masamitsu Eitoku
- Laboratory of Developmental Biology, Institute of Molecular and Cellular Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan; and
| | - Norihiko Sano
- Laboratory of Developmental Biology, Institute of Molecular and Cellular Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan; and
| | - Ryo Natsume
- Protein Structural Information Analysis Team, Japan Biological Informatics Consortium, 2-4-7 Aomi, Koto-ku, Tokyo 135-0064, Japan
| | - Norio Kudo
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Masaru Tanokura
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Toshiya Senda
- Biomedicinal Information Research Center, National Institute of Advanced Industrial Science and Technology, 2-4-7 Aomi, Koto-ku, Tokyo 135-0064, Japan
| | - Masami Horikoshi
- Laboratory of Developmental Biology, Institute of Molecular and Cellular Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan; and
- Horikoshi Gene Selector Project, Exploratory Research for Advanced Technology, Japan Science and Technology Agency, 5-9-6 Tokodai, Tsukuba, Ibaraki 300-2635, Japan
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Lin LJ, Minard LV, Johnston GC, Singer RA, Schultz MC. Asf1 can promote trimethylation of H3 K36 by Set2. Mol Cell Biol 2010; 30:1116-29. [PMID: 20048053 PMCID: PMC2820888 DOI: 10.1128/mcb.01229-09] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2009] [Revised: 10/20/2009] [Accepted: 12/22/2009] [Indexed: 12/17/2022] Open
Abstract
Asf1 is a conserved histone H3/H4 chaperone that can assemble and disassemble nucleosomes and promote histone acetylation. Set2 is an H3 K36 methyltransferase. The functions of these proteins intersect in the context of transcription elongation by RNA polymerase II: both contribute to the establishment of repressive chromatin structures that inhibit spurious intragenic transcription. Here we characterize further interactions between budding yeast (Saccharomyces cerevisiae) Asf1 and Set2 using assays of intragenic transcription, H3/H4 posttranslational modification, coding region cross-linking of Asf1 and Set2, and cooccurrence of Asf1 and Set2 in protein complexes. We find that at some genes Asf1 and Set2 control chromatin metabolism as components of separate pathways. However, the existence of a low-abundance complex containing both proteins suggests that Asf1 and Set2 can more directly collaborate in chromatin regulation. Consistent with this possibility, we show that Asf1 stimulates Set2 occupancy of the coding region of a highly transcribed gene by a mechanism that depends on Asf1 binding to H3/H4. This function of Asf1 promotes the switch from di- to trimethylation of H3 K36 at that gene. These results support the view that Set2 function in chromatin metabolism can intimately involve histone chaperone Asf1.
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Affiliation(s)
- Ling-ju Lin
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2H7, Department of Microbiology and Immunology, Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada B3H 1X5
| | - Laura V. Minard
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2H7, Department of Microbiology and Immunology, Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada B3H 1X5
| | - Gerald C. Johnston
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2H7, Department of Microbiology and Immunology, Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada B3H 1X5
| | - Richard A. Singer
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2H7, Department of Microbiology and Immunology, Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada B3H 1X5
| | - Michael C. Schultz
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2H7, Department of Microbiology and Immunology, Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada B3H 1X5
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The Saccharomyces cerevisiae Rad6 postreplication repair and Siz1/Srs2 homologous recombination-inhibiting pathways process DNA damage that arises in asf1 mutants. Mol Cell Biol 2009; 29:5226-37. [PMID: 19635810 DOI: 10.1128/mcb.00894-09] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The Asf1 and Rad6 pathways have been implicated in a number of common processes such as suppression of gross chromosomal rearrangements (GCRs), DNA repair, modification of chromatin, and proper checkpoint functions. We examined the relationship between Asf1 and different gene products implicated in postreplication repair (PRR) pathways in the suppression of GCRs, checkpoint function, sensitivity to hydroxyurea (HU) and methyl methanesulfonate (MMS), and ubiquitination of proliferating cell nuclear antigen (PCNA). We found that defects in Rad6 PRR pathway and Siz1/Srs2 homologous recombination suppression (HRS) pathway genes suppressed the increased GCR rates seen in asf1 mutants, which was independent of translesion bypass polymerases but showed an increased dependency on Dun1. Combining an asf1 deletion with different PRR mutations resulted in a synergistic increase in sensitivity to chronic HU and MMS treatment; however, these double mutants were not checkpoint defective, since they were capable of recovering from acute treatment with HU. Interestingly, we found that Asf1 and Rad6 cooperate in ubiquitination of PCNA, indicating that Rad6 and Asf1 function in parallel pathways that ubiquitinate PCNA. Our results show that ASF1 probably contributes to the maintenance of genome stability through multiple mechanisms, some of which involve the PRR and HRS pathways.
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Putnam CD, Jaehnig EJ, Kolodner RD. Perspectives on the DNA damage and replication checkpoint responses in Saccharomyces cerevisiae. DNA Repair (Amst) 2009; 8:974-82. [PMID: 19477695 DOI: 10.1016/j.dnarep.2009.04.021] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The DNA damage and replication checkpoints are believed to primarily slow the progression of the cell cycle to allow DNA repair to occur. Here we summarize known aspects of the Saccharomyces cerevisiae checkpoints including how these responses are integrated into downstream effects on the cell cycle, chromatin, DNA repair, and cytoplasmic targets. Analysis of the transcriptional response demonstrates that it is far more complex and less relevant to the repair of DNA damage than the bacterial SOS response. We also address more speculative questions regarding potential roles of the checkpoint during the normal S-phase and how current evidence hints at a checkpoint activation mechanism mediated by positive feedback that amplifies initial damage signals above a minimum threshold.
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Affiliation(s)
- Christopher D Putnam
- Ludwig Institute for Cancer Research, Department of Medicine and Cancer Center, University of California School of Medicine, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0669, United States.
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Padmanabhan B, Kataoka K, Umehara T, Adachi N, Yokoyama S, Horikoshi M. Structural similarity between histone chaperone Cia1p/Asf1p and DNA-binding protein NF-kappaB. J Biochem 2009; 138:821-9. [PMID: 16428312 DOI: 10.1093/jb/mvi182] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The structural relationships between histone-binding proteins and DNA-binding proteins are important, since nucleosome-interacting factors possess histone-binding and/or DNA-binding components. S. cerevisiae (Sc) Cia1p/Asf1p, a homologue of human CIA (CCG1-interacting factor A), is the most evolutionarily conserved histone chaperone, which facilitates nucleosome assembly by interacting with the nucleosome entry site of the core histones H3/H4. The crystal structure of the evolutionarily conserved domain (residues 1-169) of Cia1p (ScCia1p-DeltaC2) was determined at 2.95 A resolution. The refined model contains 166 residues in the asymmetric unit. The overall tertiary structure resembles a beta-sandwich fold, and belongs to the "switched" immunoglobulin class of proteins. The crystal structure suggests that ScCia1p-DeltaC2 is structurally related to the DNA-binding proteins, such as NF-kappaB and its family members. This is the first examination of the structural similarities between a histone chaperone and DNA-binding proteins. We discuss the possibilities that the strands beta3 and beta4, which possess highly electronegative surface potentials, are the important regions for the interaction with core histones, and that the histone chaperone ScCia1p/Asf1p and the DNA-binding protein NF-kappaB may have evolved from the same prototypal protein class.
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Affiliation(s)
- Balasundaram Padmanabhan
- Horikoshi Gene Selector Project, Exploratory Research for Advanced Technology (ERATO), Japan Science and Technology Corporation (JST), 5-9-6 Tokodai, Tsukuba 300-2635
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Groth A. Replicating chromatin: a tale of histonesThis paper is one of a selection of papers published in this Special Issue, entitled CSBMCB’s 51st Annual Meeting – Epigenetics and Chromatin Dynamics, and has undergone the Journal’s usual peer review process. Biochem Cell Biol 2009; 87:51-63. [DOI: 10.1139/o08-102] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Chromatin serves structural and functional roles crucial for genome stability and correct gene expression. This organization must be reproduced on daughter strands during replication to maintain proper overlay of epigenetic fabric onto genetic sequence. Nucleosomes constitute the structural framework of chromatin and carry information to specify higher-order organization and gene expression. When replication forks traverse the chromosomes, nucleosomes are transiently disrupted, allowing the replication machinery to gain access to DNA. Histone recycling, together with new deposition, ensures reassembly on nascent DNA strands. The aim of this review is to discuss how histones — new and old — are handled at the replication fork, highlighting new mechanistic insights and revisiting old paradigms.
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Affiliation(s)
- Anja Groth
- Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen, Denmark (e-mail: )
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42
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Lam MHY, Urban-Grimal D, Bugnicourt A, Greenblatt JF, Haguenauer-Tsapis R, Emili A. Interaction of the deubiquitinating enzyme Ubp2 and the e3 ligase Rsp5 is required for transporter/receptor sorting in the multivesicular body pathway. PLoS One 2009; 4:e4259. [PMID: 19165343 PMCID: PMC2626285 DOI: 10.1371/journal.pone.0004259] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2008] [Accepted: 12/10/2008] [Indexed: 11/30/2022] Open
Abstract
Protein ubiquitination is essential for many events linked to intracellular protein trafficking. We sought to elucidate the possible involvement of the S. cerevisiae deubiquitinating enzyme Ubp2 in transporter and receptor trafficking after we (this study) and others established that affinity purified Ubp2 interacts stably with the E3 ubiquitin ligase Rsp5 and the (ubiquitin associated) UBA domain containing protein Rup1. UBP2 interacts genetically with RSP5, while Rup1 facilitates the tethering of Ubp2 to Rsp5 via a PPPSY motif. Using the uracil permease Fur4 as a model reporter system, we establish a role for Ubp2 in membrane protein turnover. Similar to hypomorphic rsp5 alleles, cells deleted for UBP2 exhibited a temporal stabilization of Fur4 at the plasma membrane, indicative of perturbed protein trafficking. This defect was ubiquitin dependent, as a Fur4 N-terminal ubiquitin fusion construct bypassed the block and restored sorting in the mutant. Moreover, the defect was absent in conditions where recycling was absent, implicating Ubp2 in sorting at the multivesicular body. Taken together, our data suggest a previously overlooked role for Ubp2 as a positive regulator of Rsp5-mediated membrane protein trafficking subsequent to endocytosis.
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Affiliation(s)
- Mandy H. Y. Lam
- Banting and Best Department of Medical Research, Donnelly Centre for Cellular and Biomolecular Research, Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | | | - Amandine Bugnicourt
- Institut Jacques Monod-CNRS, Universités Paris VI and Paris VII, Paris, France
| | - Jack F. Greenblatt
- Banting and Best Department of Medical Research, Donnelly Centre for Cellular and Biomolecular Research, Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | | | - Andrew Emili
- Banting and Best Department of Medical Research, Donnelly Centre for Cellular and Biomolecular Research, Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- * E-mail:
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Chromatin assembly factors Asf1 and CAF-1 have overlapping roles in deactivating the DNA damage checkpoint when DNA repair is complete. Proc Natl Acad Sci U S A 2009; 106:1151-6. [PMID: 19164567 DOI: 10.1073/pnas.0812578106] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In response to a DNA double-strand break (DSB), chromatin is rapidly modified by the damage dependent checkpoint kinases. Also, disassembly of chromatin occurs at the break site. The damage-induced modification of chromatin structure is involved in the maintenance of the checkpoint. However, it has not been determined how chromatin is restored to its undamaged state when DSB repair is complete. Here, we show the involvement of two chromatin assembly factors (CAFs), Asf1 and CAF-1, in turning off the DNA damage checkpoint in budding yeast. DSB repair or formation of gamma-H2AX does not depend on either the CAF-1 protein, Cac1, or Asf1. Absence of these proteins does not impair the ability of cells to resume cell cycle progression in the presence of an unrepaired DSB (adaptation). However, recovery from cell cycle checkpoint arrest when the DSB is repaired by gene conversion is substantially defective in the absence of both CAF-1 and Asf1, whereas deleting CAC1 or ASF1 individually had little effect. We suggest that CAF-1 and Asf1 function redundantly to deactivate the checkpoint by restoring chromatin structure on the completion of DSB repair.
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Varicella-zoster virus immediate-early 63 protein interacts with human antisilencing function 1 protein and alters its ability to bind histones h3.1 and h3.3. J Virol 2008; 83:200-9. [PMID: 18971269 DOI: 10.1128/jvi.00645-08] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Varicella-zoster virus (VZV) immediate-early 63 protein (IE63) is abundantly expressed during both acute infection in vitro and latent infection in human ganglia. Using the yeast two-hybrid system, we found that VZV IE63 interacts with human antisilencing function 1 protein (ASF1). ASF1 is a nucleosome assembly factor which is a member of the H3/H4 family of histone chaperones. IE63 coimmunoprecipitated and colocalized with ASF1 in transfected cells expressing IE63 and in VZV-infected cells. IE63 also colocalized with ASF1 in both lytic and latently VZV-infected enteric neurons. ASF1 exists in two isoforms, ASF1a and ASF1b, in mammalian cells. IE63 preferentially bound to ASF1a, and the amino-terminal 30 amino acids of ASF1a were critical for its interaction with IE63. VZV IE63 amino acids 171 to 208 and putative phosphorylation sites of IE63, both of which are critical for virus replication and latency in rodents, were important for the interaction of IE63 with ASF1. Finally, we found that IE63 increased the binding of ASF1 to histone H3.1 and H3.3, which suggests that IE63 may help to regulate levels of histones in virus-infected cells. Since ASF1 mediates eviction and deposition of histones during transcription, the interaction of VZV IE63 with ASF1 may help to regulate transcription of viral or cellular genes during lytic and/or latent infection.
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45
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Chen CC, Carson JJ, Feser J, Tamburini B, Zabaronick S, Linger J, Tyler JK. Acetylated lysine 56 on histone H3 drives chromatin assembly after repair and signals for the completion of repair. Cell 2008; 134:231-43. [PMID: 18662539 DOI: 10.1016/j.cell.2008.06.035] [Citation(s) in RCA: 322] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2007] [Revised: 05/02/2008] [Accepted: 06/16/2008] [Indexed: 11/28/2022]
Abstract
DNA damage causes checkpoint activation leading to cell cycle arrest and repair, during which the chromatin structure is disrupted. The mechanisms whereby chromatin structure and cell cycle progression are restored after DNA repair are largely unknown. We show that chromatin reassembly following double-strand break (DSB) repair requires the histone chaperone Asf1 and that absence of Asf1 causes cell death, as cells are unable to recover from the DNA damage checkpoint. We find that Asf1 contributes toward chromatin assembly after DSB repair by promoting acetylation of free histone H3 on lysine 56 (K56) via the histone acetyl transferase Rtt109. Mimicking acetylation of K56 bypasses the requirement for Asf1 for chromatin reassembly and checkpoint recovery, whereas mutations that prevent K56 acetylation block chromatin reassembly after repair. These results indicate that restoration of the chromatin following DSB repair is driven by acetylated H3 K56 and that this is a signal for the completion of repair.
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Affiliation(s)
- Chin-Chuan Chen
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, CO 80045, USA
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46
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Chaperone control of the activity and specificity of the histone H3 acetyltransferase Rtt109. Mol Cell Biol 2008; 28:4342-53. [PMID: 18458063 DOI: 10.1128/mcb.00182-08] [Citation(s) in RCA: 152] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Acetylation of Saccharomyces cerevisiae histone H3 on K56 by the histone acetyltransferase (HAT) Rtt109 is important for repairing replication-associated lesions. Rtt109 purifies from yeast in complex with the histone chaperone Vps75, which stabilizes the HAT in vivo. A whole-genome screen to identify genes whose deletions have synthetic genetic interactions with rtt109Delta suggests Rtt109 has functions in addition to DNA repair. We show that in addition to its known H3-K56 acetylation activity, Rtt109 is also an H3-K9 HAT, and we show that Rtt109 and Gcn5 are the only H3-K9 HATs in vivo. Rtt109's H3-K9 acetylation activity in vitro is enhanced strongly by Vps75. Another histone chaperone, Asf1, and Vps75 are both required for acetylation of lysine 9 on H3 (H3-K9ac) in vivo by Rtt109, whereas H3-K56ac in vivo requires only Asf1. Asf1 also physically interacts with the nuclear Hat1/Hat2/Hif1 complex that acetylates H4-K5 and H4-K12. We suggest Asf1 is capable of assembling into chromatin H3-H4 dimers diacetylated on both H4-K5/12 and H3-K9/56.
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47
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Grigsby IF, Finger FP. UNC-85, a C. elegans homolog of the histone chaperone Asf1, functions in post-embryonic neuroblast replication. Dev Biol 2008; 319:100-9. [PMID: 18490010 DOI: 10.1016/j.ydbio.2008.04.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2007] [Revised: 04/08/2008] [Accepted: 04/08/2008] [Indexed: 11/28/2022]
Abstract
Normal animal development requires accurate cell divisions, not only in the early stages of rapid embryonic cleavages, but also in later developmental stages. The Caenorhabditis elegans unc-85 gene is implicated only in cell divisions that occur post-embryonically, primarily in terminal neuronal lineages. Variable post-embryonic cell division failures in ventral cord motoneuron precursors result in uncoordinated locomotion of unc-85 mutant larvae by the second larval stage. These neuroblast cell division failures often result in unequally sized daughter nuclei, and sometimes in nuclear fusions. Using a combination of conventional mapping techniques and microarray analysis, we cloned the unc-85 gene, and find that it encodes one of two C. elegans homologs of the yeast Anti-silencing function 1 (Asf1) histone chaperone. The unc-85 gene is expressed in replicating cells throughout development, and the protein is localized in nuclei. Examination of null mutants confirms that embryonic neuroblast cell divisions occur normally, but post-embryonic neuroblast cell divisions fail. Analysis of the DNA content of the mutant neurons indicates that defective replication in post-embryonic neuroblasts gives rise to ventral cord neurons with an average DNA content of approximately 2.5 n. We conclude that UNC-85 functions in post-embryonic DNA replication in ventral cord motor neuron precursors.
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Affiliation(s)
- Iwen F Grigsby
- Biology Department and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, 110 8th Street, Biotech-BCHM-2, Troy, NY 12180, USA
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48
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Malay AD, Umehara T, Matsubara-Malay K, Padmanabhan B, Yokoyama S. Crystal structures of fission yeast histone chaperone Asf1 complexed with the Hip1 B-domain or the Cac2 C terminus. J Biol Chem 2008; 283:14022-31. [PMID: 18334479 DOI: 10.1074/jbc.m800594200] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The assembly of core histones onto eukaryotic DNA is modulated by several histone chaperone complexes, including Asf1, CAF-1, and HIRA. Asf1 is a unique histone chaperone that participates in both the replication-dependent and replication-independent pathways. Here we report the crystal structures of the apo-form of fission yeast Asf1/Cia1 (SpAsf1N; residues 1-161) as well as its complexes with the B-domain of the fission yeast HIRA orthologue Hip1 (Hip1B) and the C-terminal region of the Cac2 subunit of CAF-1 (Cac2C). The mode of the fission yeast Asf1N-Hip1B recognition is similar to that of the human Asf1-HIRA recognition, suggesting that Asf1N recognition of Hip1B/HIRA is conserved from yeast to mammals. Interestingly, Hip1B and Cac2C show remarkably similar interaction modes with Asf1. The binding between Asf1N and Hip1B was almost completely abolished by the D37A and L60A/V62A mutations in Asf1N, indicating the critical role of salt bridge and van der Waals contacts in the complex formation. Consistently, both of the aforementioned Asf1 mutations also drastically reduced the binding to Cac2C. These results provide a structural basis for a mutually exclusive Asf1-binding model of CAF-1 and HIRA/Hip1, in which Asf1 and CAF-1 assemble histones H3/H4 (H3.1/H4 in vertebrates) in a replication-dependent pathway, whereas Asf1 and HIRA/Hip1 assemble histones H3/H4 (H3.3/H4 in vertebrates) in a replication-independent pathway.
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Affiliation(s)
- Ali D Malay
- Yokohama Institute, RIKEN, Tsurumi, Yokohama 230-0045, Japan
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49
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Müller B, Blackburn J, Feijoo C, Zhao X, Smythe C. DNA-activated protein kinase functions in a newly observed S phase checkpoint that links histone mRNA abundance with DNA replication. ACTA ACUST UNITED AC 2007; 179:1385-98. [PMID: 18158334 PMCID: PMC2373486 DOI: 10.1083/jcb.200708106] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
DNA and histone synthesis are coupled and ongoing replication is required to maintain histone gene expression. Here, we expose S phase–arrested cells to the kinase inhibitors caffeine and LY294002. This uncouples DNA replication from histone messenger RNA (mRNA) abundance, altering the efficiency of replication stress–induced histone mRNA down-regulation. Interference with caffeine-sensitive checkpoint kinases ataxia telangiectasia and Rad3 related (ATR)/ataxia telangiectasia mutated (ATM) does not affect histone mRNA down- regulation, which indicates that ATR/ATM alone cannot account for such coupling. LY294002 potentiates caffeine's ability to uncouple histone mRNA stabilization from replication only in cells containing functional DNA-activated protein kinase (DNA-PK), which indicates that DNA-PK is the target of LY294002. DNA-PK is activated during replication stress and DNA-PK signaling is enhanced when ATR/ATM signaling is abrogated. Histone mRNA decay does not require Chk1/Chk2. Replication stress induces phosphorylation of UPF1 but not hairpin-binding protein/stem-loop binding protein at S/TQ sites, which are preferred substrate recognition motifs of phosphatidylinositol 3-kinase–like kinases, which indicates that histone mRNA stability may be directly controlled by ATR/ATM- and DNA-PK–mediated phosphorylation of UPF1.
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Affiliation(s)
- Berndt Müller
- School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Aberdeen AB25 2ZD, Scotland, UK
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50
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Examining protein protein interactions using endogenously tagged yeast arrays: the cross-and-capture system. Genome Res 2007; 17:1774-82. [PMID: 17989249 DOI: 10.1101/gr.6667007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Comprehensive approaches to detect protein-protein interactions (PPIs) have been most successful in the yeast model system. Here we present "Cross-and-Capture," a novel assay for rapid, sensitive assessment of PPIs via pulldown of differently tagged yeast strain arrays. About 500 yeast genes that function in DNA replication, repair, and recombination and nuclear proteins of unknown function were chromosomally tagged with six histidine residues or triple VSV epitopes. We demonstrate that the assay can interrogate a wide range of previously known protein complexes with increased resolution and sensitivity. Furthermore, we use "Cross-and-Capture" to identify two novel protein complexes: Rtt101p-Mms1p and Sae2p-Mre11p. The Rtt101p-Mms1p interaction was subsequently characterized by genetic and functional analyses. Our studies establish the "Cross-and-Capture" assay as a novel, versatile tool that provides a valuable complement for the next generation of yeast proteomic studies.
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