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Kadyrova LY, Mieczkowski PA, Kadyrov FA. MutLα suppresses error-prone DNA mismatch repair and preferentially protects noncoding DNA from mutations. J Biol Chem 2024; 300:107406. [PMID: 38782208 PMCID: PMC11231602 DOI: 10.1016/j.jbc.2024.107406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2024] [Revised: 05/15/2024] [Accepted: 05/16/2024] [Indexed: 05/25/2024] Open
Abstract
The DNA mismatch repair (MMR) system promotes genome stability and protects humans from certain types of cancer. Its primary function is the correction of DNA polymerase errors. MutLα is an important eukaryotic MMR factor. We have examined the contributions of MutLα to maintaining genome stability. We show here that loss of MutLα in yeast increases the genome-wide mutation rate by ∼130-fold and generates a genome-wide mutation spectrum that consists of small indels and base substitutions. We also show that loss of yeast MutLα leads to error-prone MMR that produces T > C base substitutions in 5'-ATA-3' sequences. In agreement with this finding, our examination of human whole-genome DNA sequencing data has revealed that loss of MutLα in induced pluripotent stem cells triggers error-prone MMR that leads to the formation of T > C mutations in 5'-NTN-3' sequences. Our further analysis has shown that MutLα-independent MMR plays a role in suppressing base substitutions in N3 homopolymeric runs. In addition, we describe that MutLα preferentially protects noncoding DNA from mutations. Our study defines the contributions of MutLα-dependent and independent mechanisms to genome-wide MMR.
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Affiliation(s)
- Lyudmila Y Kadyrova
- Division of Biochemistry and Molecular Biology, Department of Biomedical Sciences, Southern Illinois University School of Medicine, Carbondale, Illinois, USA
| | - Piotr A Mieczkowski
- Department of Genetics, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Farid A Kadyrov
- Division of Biochemistry and Molecular Biology, Department of Biomedical Sciences, Southern Illinois University School of Medicine, Carbondale, Illinois, USA.
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2
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Kadyrova LY, Mieczkowski PA, Kadyrov FA. MutLα suppresses error-prone DNA mismatch repair and preferentially protects noncoding DNA from mutations. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.01.587563. [PMID: 38617288 PMCID: PMC11014525 DOI: 10.1101/2024.04.01.587563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
The DNA mismatch repair (MMR) system promotes genome stability and protects humans from certain types of cancer. Its primary function is the correction of DNA polymerase errors. MutLα is an important eukaryotic MMR factor. We have examined the contributions of MutLα to maintaining genome stability. We show here that loss of MutLα in yeast increases the genome-wide mutation rate by ~130-fold and generates a genome-wide mutation spectrum that consists of small indels and base substitutions. We also show that loss of yeast MutLα leads to error-prone MMR that produces T>C base substitutions in 5'-ATA-3' sequences. In agreement with this finding, our examination of human whole genome DNA sequencing data has revealed that loss of MutLα in induced pluripotent stem cells triggers error-prone MMR that leads to the formation of T>C mutations in 5'-NTN-3' sequences. Our further analysis has shown that MutLα-independent MMR plays a role in suppressing base substitutions in N3 homopolymeric runs. In addition, we describe that MutLα preferentially defends noncoding DNA from mutations. Our study defines the contributions of MutLα-dependent and independent mechanisms to genome-wide MMR.
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Affiliation(s)
- Lyudmila Y. Kadyrova
- Division of Biochemistry and Molecular Biology, Department of Biomedical Sciences, Southern Illinois University School of Medicine, Carbondale, IL 62901, USA
| | - Piotr A. Mieczkowski
- Department of Genetics, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599, USA
| | - Farid A. Kadyrov
- Division of Biochemistry and Molecular Biology, Department of Biomedical Sciences, Southern Illinois University School of Medicine, Carbondale, IL 62901, USA
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3
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Wang L, Xue Y, Yang S, Bo T, Xu J, Wang W. Mismatch Repair Protein Msh2 Is Necessary for Macronuclear Stability and Micronuclear Division in Tetrahymena thermophila. Int J Mol Sci 2023; 24:10559. [PMID: 37445734 DOI: 10.3390/ijms241310559] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 06/20/2023] [Accepted: 06/22/2023] [Indexed: 07/15/2023] Open
Abstract
Mismatch repair (MMR) is a conserved mechanism that is primarily responsible for the repair of DNA mismatches during DNA replication. Msh2 forms MutS heterodimer complexes that initiate the MMR in eukaryotes. The function of Msh2 is less clear under different chromatin structures. Tetrahymena thermophila contains a transcriptionally active macronucleus (MAC) and a transcriptionally silent micronucleus (MIC) in the same cytoplasm. Msh2 is localized in the MAC and MIC during vegetative growth. Msh2 is localized in the perinuclear region around the MIC and forms a spindle-like structure as the MIC divides. During the early conjugation stage, Msh2 is localized in the MIC and disappears from the parental MAC. Msh2 is localized in the new MAC and new MIC during the late conjugation stage. Msh2 also forms a spindle-like structure with a meiotic MIC and mitotic gametic nucleus. MSH2 knockdown inhibits the division of MAC and MIC during vegetative growth and affects cellular proliferation. MSH2 knockdown mutants are sensitive to cisplatin treatment. MSH2 knockdown also affects micronuclear meiosis and gametogenesis during sexual development. Furthermore, Msh2 interacts with MMR-dependent and MMR-independent factors. Therefore, Msh2 is necessary for macronuclear stability, as well as micronuclear mitosis and meiosis in Tetrahymena.
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Affiliation(s)
- Lin Wang
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China
| | - Yuhuan Xue
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China
| | - Sitong Yang
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China
| | - Tao Bo
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China
- Shanxi Key Laboratory of Biotechnology, Taiyuan 030006, China
| | - Jing Xu
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China
- School of Life Science, Shanxi University, Taiyuan 030006, China
| | - Wei Wang
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China
- Shanxi Key Laboratory of Biotechnology, Taiyuan 030006, China
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4
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Kadyrova LY, Mieczkowski PA, Kadyrov FA. Genome-wide contributions of the MutSα- and MutSβ-dependent DNA mismatch repair pathways to the maintenance of genetic stability in S. cerevisiae. J Biol Chem 2023; 299:104705. [PMID: 37059180 DOI: 10.1016/j.jbc.2023.104705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 04/07/2023] [Accepted: 04/08/2023] [Indexed: 04/16/2023] Open
Abstract
The DNA mismatch repair (MMR) system is a major DNA repair system that suppresses inherited and sporadic cancers in humans. In eukaryotes the MutSα-dependent and MutSβ-dependent MMR pathways correct DNA polymerase errors. Here, we investigated these two pathways on a whole-genome level in S. cerevisiae. We found that inactivation of MutSα-dependent MMR by deletion of the MSH6 gene increases the genome-wide mutation rate by ∼17-fold, and loss of MutSβ-dependent MMR via deletion of MSH3 elevates the genome-wide mutation rate by ∼4-fold. We also found that MutSα-dependent MMR does not show a preference for protecting coding or noncoding DNA from mutations, whereas MutSβ-dependent MMR preferentially protects noncoding DNA from mutations. The most frequent mutations in the msh6Δ strain are C>T transitions, whereas 1-6-bp deletions are the most common genetic alterations in the msh3Δ strain. Strikingly, MutSα-dependent MMR is more important than MutSβ-dependent MMR for protection from 1-bp insertions, while MutSβ-dependent MMR has a more critical role in the defense against 1-bp deletions and 2-6-bp indels. We also determined that a mutational signature of yeast MSH6 loss is similar to mutational signatures of human MMR deficiency. Furthermore, our analysis showed that compared to other 5'-NCN-3' trinucleotides, 5'-GCA-3' trinucleotides are at the highest risk of accumulating C>T transitions at the central position in the msh6Δ cells and that the presence of a G/A base at the -1 position is important for the efficient MutSα-dependent suppression of C>T transitions. Our results highlight key differences between the roles of the MutSα-dependent and MutSβ-dependent MMR pathways.
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Affiliation(s)
- Lyudmila Y Kadyrova
- Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale, IL 62901, USA
| | - Piotr A Mieczkowski
- Department of Genetics, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599, USA
| | - Farid A Kadyrov
- Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale, IL 62901, USA.
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Zhang Y, Zhang Q, Zhang Y, Han J. The Role of Histone Modification in DNA Replication-Coupled Nucleosome Assembly and Cancer. Int J Mol Sci 2023; 24:ijms24054939. [PMID: 36902370 PMCID: PMC10003558 DOI: 10.3390/ijms24054939] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 01/28/2023] [Accepted: 01/29/2023] [Indexed: 03/08/2023] Open
Abstract
Histone modification regulates replication-coupled nucleosome assembly, DNA damage repair, and gene transcription. Changes or mutations in factors involved in nucleosome assembly are closely related to the development and pathogenesis of cancer and other human diseases and are essential for maintaining genomic stability and epigenetic information transmission. In this review, we discuss the role of different types of histone posttranslational modifications in DNA replication-coupled nucleosome assembly and disease. In recent years, histone modification has been found to affect the deposition of newly synthesized histones and the repair of DNA damage, further affecting the assembly process of DNA replication-coupled nucleosomes. We summarize the role of histone modification in the nucleosome assembly process. At the same time, we review the mechanism of histone modification in cancer development and briefly describe the application of histone modification small molecule inhibitors in cancer therapy.
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Hu X, Jin X, Cao X, Liu B. The Anaphase-Promoting Complex/Cyclosome Is a Cellular Ageing Regulator. Int J Mol Sci 2022; 23:ijms232315327. [PMID: 36499653 PMCID: PMC9740938 DOI: 10.3390/ijms232315327] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 11/30/2022] [Accepted: 12/02/2022] [Indexed: 12/11/2022] Open
Abstract
The anaphase-promoting complex/cyclosome (APC/C) is a complicated cellular component that plays significant roles in regulating the cell cycle process of eukaryotic organisms. The spatiotemporal regulation mechanisms of APC/C in distinct cell cycle transitions are no longer mysterious, and the components of this protein complex are gradually identified and characterized. Given the close relationship between the cell cycle and lifespan, it is urgent to understand the roles of APC/C in lifespan regulation, but this field still seems to have not been systematically summarized. Furthermore, although several reviews have reported the roles of APC/C in cancer, there are still gaps in the summary of its roles in other age-related diseases. In this review, we propose that the APC/C is a novel cellular ageing regulator based on its indispensable role in the regulation of lifespan and its involvement in age-associated diseases. This work provides an extensive review of aspects related to the underlying mechanisms of APC/C in lifespan regulation and how it participates in age-associated diseases. More comprehensive recognition and understanding of the relationship between APC/C and ageing and age-related diseases will increase the development of targeted strategies for human health.
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Affiliation(s)
- Xiangdong Hu
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou 311300, China
| | - Xuejiao Jin
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou 311300, China
| | - Xiuling Cao
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou 311300, China
- Correspondence: (X.C.); (B.L.)
| | - Beidong Liu
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou 311300, China
- Department of Chemistry and Molecular Biology, University of Gothenburg, 41390 Gothenburg, Sweden
- Correspondence: (X.C.); (B.L.)
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The nuclease activity of DNA2 promotes exonuclease 1-independent mismatch repair. J Biol Chem 2022; 298:101831. [PMID: 35300981 PMCID: PMC9036127 DOI: 10.1016/j.jbc.2022.101831] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 03/09/2022] [Accepted: 03/10/2022] [Indexed: 12/03/2022] Open
Abstract
The DNA mismatch repair (MMR) system is a major DNA repair system that corrects DNA replication errors. In eukaryotes, the MMR system functions via mechanisms both dependent on and independent of exonuclease 1 (EXO1), an enzyme that has multiple roles in DNA metabolism. Although the mechanism of EXO1-dependent MMR is well understood, less is known about EXO1-independent MMR. Here, we provide genetic and biochemical evidence that the DNA2 nuclease/helicase has a role in EXO1-independent MMR. Biochemical reactions reconstituted with purified human proteins demonstrated that the nuclease activity of DNA2 promotes an EXO1-independent MMR reaction via a mismatch excision-independent mechanism that involves DNA polymerase δ. We show that DNA polymerase ε is not able to replace DNA polymerase δ in the DNA2-promoted MMR reaction. Unlike its nuclease activity, the helicase activity of DNA2 is dispensable for the ability of the protein to enhance the MMR reaction. Further examination established that DNA2 acts in the EXO1-independent MMR reaction by increasing the strand-displacement activity of DNA polymerase δ. These data reveal a mechanism for EXO1-independent mismatch repair.
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Wang X, Wang L, Dou J, Yu T, Cao P, Fan N, Borjigin U, Nashun B. Distinct role of histone chaperone Asf1a and Asf1b during fertilization and pre-implantation embryonic development in mice. Epigenetics Chromatin 2021; 14:55. [PMID: 34906203 PMCID: PMC8670131 DOI: 10.1186/s13072-021-00430-7] [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: 09/02/2021] [Accepted: 11/30/2021] [Indexed: 11/16/2022] Open
Abstract
Background Asf1 is a well-conserved histone chaperone that regulates multiple cellular processes in different species. Two paralogous genes, Asf1a and Asf1b exist in mammals, but their role during fertilization and early embryogenesis remains to be investigated further. Methods We analyzed the dynamics of histone chaperone Asf1a and Asf1b in oocytes and pre-implantation embryos in mice by immunofluorescence and real-time quantitative PCR, and further investigated the role of Asf1a and Asf1b during fertilization and pre-implantation development by specific Morpholino oligos-mediated knock down approach. Results Immunofluorescence with specific antibodies revealed that both Asf1a and Asf1b were deposited in the nuclei of fully grown oocytes, accumulated abundantly in zygote and 2-cell embryonic nuclei, but turned low at 4-cell stage embryos. In contrast to the weak but definite nuclear deposition of Asf1a, Asf1b disappeared from embryonic nuclei at morula and blastocyst stages. The knockdown of Asf1a and Asf1b by specific Morpholino oligos revealed that Asf1a but not Asf1b was required for the histone H3.3 assembly in paternal pronucleus. However, knockdown of either Asf1a or Asf1b expression decreased developmental potential of pre-implantation embryos. Furthermore, while Asf1a KD severely reduced H3K56 acetylation level and the expression of Oct4 in blastocyst stage embryos, Asf1b KD almost eliminated nuclear accumulation of proliferating cell marker-PCNA in morula stage embryos. These results suggested that histone chaperone Asf1a and Asf1b play distinct roles during fertilization and pre-implantation development in mice. Conclusions Our data suggested that both Asf1a and Asf1b are required for pre-implantation embryonic development. Asf1a regulates H3K56ac levels and Oct4 expression, while Asf1b safeguards pre-implantation embryo development by regulating cell proliferation. We also showed that Asf1a, but not Asf1b, was necessary for the assembly of histone H3.3 in paternal pronuclei after fertilization. Supplementary Information The online version contains supplementary material available at 10.1186/s13072-021-00430-7.
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Affiliation(s)
- Xuemei Wang
- State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, 24 Zhaojun Road, Yuquan District, Hohhot, 010070, Inner Mongolia, China
| | - Lu Wang
- State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, 24 Zhaojun Road, Yuquan District, Hohhot, 010070, Inner Mongolia, China
| | - Jie Dou
- State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, 24 Zhaojun Road, Yuquan District, Hohhot, 010070, Inner Mongolia, China
| | - Tianjiao Yu
- State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, 24 Zhaojun Road, Yuquan District, Hohhot, 010070, Inner Mongolia, China
| | - Pengbo Cao
- State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, 24 Zhaojun Road, Yuquan District, Hohhot, 010070, Inner Mongolia, China
| | - Na Fan
- State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, 24 Zhaojun Road, Yuquan District, Hohhot, 010070, Inner Mongolia, China
| | - Uyunbilig Borjigin
- State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, 24 Zhaojun Road, Yuquan District, Hohhot, 010070, Inner Mongolia, China
| | - Buhe Nashun
- State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, 24 Zhaojun Road, Yuquan District, Hohhot, 010070, Inner Mongolia, China.
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Chakraborty U, Shen ZJ, Tyler J. Chaperoning histones at the DNA repair dance. DNA Repair (Amst) 2021; 108:103240. [PMID: 34687987 DOI: 10.1016/j.dnarep.2021.103240] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 09/28/2021] [Accepted: 10/03/2021] [Indexed: 12/15/2022]
Abstract
Unlike all other biological molecules that are degraded and replaced if damaged, DNA must be repaired as chromosomes cannot be replaced. Indeed, DNA endures a wide variety of structural damage that need to be repaired accurately to maintain genomic stability and proper functioning of cells and to prevent mutation leading to disease. Given that the genome is packaged into chromatin within eukaryotic cells, it has become increasingly evident that the chromatin context of DNA both facilitates and regulates DNA repair processes. In this review, we discuss mechanisms involved in removal of histones (chromatin disassembly) from around DNA lesions, by histone chaperones and chromatin remodelers, that promotes accessibility of the DNA repair machinery. We also elaborate on how the deposition of core histones and specific histone variants onto DNA (chromatin assembly) during DNA repair promotes repair processes, the role of histone post translational modifications in these processes and how chromatin structure is reestablished after DNA repair is complete.
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Affiliation(s)
- Ujani Chakraborty
- Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, 1300 York Avenue, New York, NY 10065, USA
| | - Zih-Jie Shen
- Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, 1300 York Avenue, New York, NY 10065, USA
| | - Jessica Tyler
- Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, 1300 York Avenue, New York, NY 10065, USA.
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10
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The Amazing Acrobat: Yeast's Histone H3K56 Juggles Several Important Roles While Maintaining Perfect Balance. Genes (Basel) 2021; 12:genes12030342. [PMID: 33668997 PMCID: PMC7996553 DOI: 10.3390/genes12030342] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 02/22/2021] [Accepted: 02/23/2021] [Indexed: 01/16/2023] Open
Abstract
Acetylation on lysine 56 of histone H3 of the yeast Saccharomyces cerevisiae has been implicated in many cellular processes that affect genome stability. Despite being the object of much research, the complete scope of the roles played by K56 acetylation is not fully understood even today. The acetylation is put in place at the S-phase of the cell cycle, in order to flag newly synthesized histones that are incorporated during DNA replication. The signal is removed by two redundant deacetylases, Hst3 and Hst4, at the entry to G2/M phase. Its crucial location, at the entry and exit points of the DNA into and out of the nucleosome, makes this a central modification, and dictates that if acetylation and deacetylation are not well concerted and executed in a timely fashion, severe genomic instability arises. In this review, we explore the wealth of information available on the many roles played by H3K56 acetylation and the deacetylases Hst3 and Hst4 in DNA replication and repair.
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11
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Abstract
DNA mismatch repair (MMR) is a highly conserved genome stabilizing pathway that corrects DNA replication errors, limits chromosomal rearrangements, and mediates the cellular response to many types of DNA damage. Counterintuitively, MMR is also involved in the generation of mutations, as evidenced by its role in causing somatic triplet repeat expansion in Huntington’s disease (HD) and other neurodegenerative disorders. In this review, we discuss the current state of mechanistic knowledge of MMR and review the roles of key enzymes in this pathway. We also present the evidence for mutagenic function of MMR in CAG repeat expansion and consider mechanistic hypotheses that have been proposed. Understanding the role of MMR in CAG expansion may shed light on potential avenues for therapeutic intervention in HD.
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Affiliation(s)
- Ravi R Iyer
- CHDI Management/CHDI Foundation, Princeton, NJ, USA
| | - Anna Pluciennik
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA, USA
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12
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Characterization of Infants with Idiopathic Transient and Persistent T Cell Lymphopenia Identified by Newborn Screening-a Single-Center Experience in New York State. J Clin Immunol 2021; 41:610-620. [PMID: 33411154 DOI: 10.1007/s10875-020-00957-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 12/26/2020] [Indexed: 12/15/2022]
Abstract
PURPOSE Newborn screening (NBS) quantifies T cell receptor excision circles (TREC) and identifies infants with T cell lymphopenia (TCL). This study elucidates the demographics, laboratory characteristics, genetics, and clinical outcomes following live viral vaccine administration of term infants with transient or persistent idiopathic TCL. METHODS A single-center retrospective analysis was performed from September 2010 through June 2018. Laboratory variables were compared with Mann-Whitney tests. Correlations between initial TREC levels and T cell counts were determined by Spearman tests. RESULTS Twenty-two transient and 21 persistent TCL infants were identified. Males comprised 68% of the transient and 52% of the persistent TCL cohorts. Whites comprised 23% of the transient and 29% of the persistent cohorts. Median initial TREC levels did not differ (66 vs. 60 TRECs/μL of blood, P = 0.58). The transient cohort had higher median initial CD3+ (2135 vs. 1169 cells/μL, P < 0.001), CD4+ (1460 vs. 866 cells/μL, P < 0.001), and CD8+ (538 vs. 277 cells/μL, P < 0.001) counts. The median age of resolution for the transient cohort was 38 days. Genetic testing revealed 2 genes of interest which warrant further study and several variants of uncertain significance in immunology-related genes in the persistent cohort. 19 transient and 14 persistent subjects received the initial rotavirus and/or MMRV immunization. No adverse reactions to live viral vaccines were reported in either cohort. CONCLUSION Transient and persistent TCL infants differ by demographic, laboratory, and clinical characteristics. Select transient and persistent TCL patients may safely receive live attenuated viral vaccines, but larger confirmatory studies are needed.
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Mackenroth B, Alani E. Collaborations between chromatin and nuclear architecture to optimize DNA repair fidelity. DNA Repair (Amst) 2021; 97:103018. [PMID: 33285474 PMCID: PMC8486310 DOI: 10.1016/j.dnarep.2020.103018] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 10/18/2020] [Accepted: 11/05/2020] [Indexed: 01/22/2023]
Abstract
Homologous recombination (HR), considered the highest fidelity DNA double-strand break (DSB) repair pathway that a cell possesses, is capable of repairing multiple DSBs without altering genetic information. However, in "last resort" scenarios, HR can be directed to low fidelity subpathways which often use non-allelic donor templates. Such repair mechanisms are often highly mutagenic and can also yield chromosomal rearrangements and/or deletions. While the choice between HR and its less precise counterpart, non-homologous end joining (NHEJ), has received much attention, less is known about how cells manage and prioritize HR subpathways. In this review, we describe work focused on how chromatin and nuclear architecture orchestrate subpathway choice and repair template usage to maintain genome integrity without sacrificing cell survival. Understanding the relationships between nuclear architecture and recombination mechanics will be critical to understand these cellular repair decisions.
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Affiliation(s)
- Beata Mackenroth
- Department of Molecular Biology and Genetics, Cornell University, 459 Biotechnology Building, Ithaca, NY, 14853-2703, United States
| | - Eric Alani
- Department of Molecular Biology and Genetics, Cornell University, 459 Biotechnology Building, Ithaca, NY, 14853-2703, United States.
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14
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Mazina OM, Somarowthu S, Kadyrova LY, Baranovskiy AG, Tahirov TH, Kadyrov FA, Mazin AV. Replication protein A binds RNA and promotes R-loop formation. J Biol Chem 2020; 295:14203-14213. [PMID: 32796030 DOI: 10.1074/jbc.ra120.013812] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 08/10/2020] [Indexed: 12/15/2022] Open
Abstract
Replication protein A (RPA), a major eukaryotic ssDNA-binding protein, is essential for all metabolic processes that involve ssDNA, including DNA replication, repair, and damage signaling. To perform its functions, RPA binds ssDNA tightly. In contrast, it was presumed that RPA binds RNA weakly. However, recent data suggest that RPA may play a role in RNA metabolism. RPA stimulates RNA-templated DNA repair in vitro and associates in vivo with R-loops, the three-stranded structures consisting of an RNA-DNA hybrid and the displaced ssDNA strand. R-loops are common in the genomes of pro- and eukaryotes, including humans, and may play an important role in transcription-coupled homologous recombination and DNA replication restart. However, the mechanism of R-loop formation remains unknown. Here, we investigated the RNA-binding properties of human RPA and its possible role in R-loop formation. Using gel-retardation and RNA/DNA competition assays, we found that RPA binds RNA with an unexpectedly high affinity (KD ≈ 100 pm). Furthermore, RPA, by forming a complex with RNA, can promote R-loop formation with homologous dsDNA. In reconstitution experiments, we showed that human DNA polymerases can utilize RPA-generated R-loops for initiation of DNA synthesis, mimicking the process of replication restart in vivo These results demonstrate that RPA binds RNA with high affinity, supporting the role of this protein in RNA metabolism and suggesting a mechanism of genome maintenance that depends on RPA-mediated DNA replication restart.
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Affiliation(s)
- Olga M Mazina
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Srinivas Somarowthu
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Lyudmila Y Kadyrova
- Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale, Illinois, USA
| | - Andrey G Baranovskiy
- Eppley Institute for Research in Cancer and Allied Diseases, Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Tahir H Tahirov
- Eppley Institute for Research in Cancer and Allied Diseases, Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Farid A Kadyrov
- Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale, Illinois, USA
| | - Alexander V Mazin
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
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15
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Dynamic human MutSα-MutLα complexes compact mismatched DNA. Proc Natl Acad Sci U S A 2020; 117:16302-16312. [PMID: 32586954 DOI: 10.1073/pnas.1918519117] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
DNA mismatch repair (MMR) corrects errors that occur during DNA replication. In humans, mutations in the proteins MutSα and MutLα that initiate MMR cause Lynch syndrome, the most common hereditary cancer. MutSα surveilles the DNA, and upon recognition of a replication error it undergoes adenosine triphosphate-dependent conformational changes and recruits MutLα. Subsequently, proliferating cell nuclear antigen (PCNA) activates MutLα to nick the error-containing strand to allow excision and resynthesis. The structure-function properties of these obligate MutSα-MutLα complexes remain mostly unexplored in higher eukaryotes, and models are predominately based on studies of prokaryotic proteins. Here, we utilize atomic force microscopy (AFM) coupled with other methods to reveal time- and concentration-dependent stoichiometries and conformations of assembling human MutSα-MutLα-DNA complexes. We find that they assemble into multimeric complexes comprising three to eight proteins around a mismatch on DNA. On the timescale of a few minutes, these complexes rearrange, folding and compacting the DNA. These observations contrast with dominant models of MMR initiation that envision diffusive MutS-MutL complexes that move away from the mismatch. Our results suggest MutSα localizes MutLα near the mismatch and promotes DNA configurations that could enhance MMR efficiency by facilitating MutLα nicking the DNA at multiple sites around the mismatch. In addition, such complexes may also protect the mismatch region from nucleosome reassembly until repair occurs, and they could potentially remodel adjacent nucleosomes.
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16
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Huang Y, Li GM. DNA mismatch repair in the context of chromatin. Cell Biosci 2020; 10:10. [PMID: 32025281 PMCID: PMC6996186 DOI: 10.1186/s13578-020-0379-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 01/24/2020] [Indexed: 12/11/2022] Open
Abstract
DNA mismatch repair (MMR) maintains replication fidelity by correcting mispaired nucleotides incorporated by DNA polymerases. Defects in MMR lead to cancers characterized by microsatellite instability. Recently, chromatin mechanisms that regulate MMR have been discovered, which sheds new light on MMR deficiency and its role in tumorigenesis. This review summarizes these chromatin-level mechanisms that regulate MMR and their implications for tumor development.
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Affiliation(s)
- Yaping Huang
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX 75390 USA
| | - Guo-Min Li
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX 75390 USA
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17
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Goellner EM. Chromatin remodeling and mismatch repair: Access and excision. DNA Repair (Amst) 2019; 85:102733. [PMID: 31698199 DOI: 10.1016/j.dnarep.2019.102733] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 09/06/2019] [Accepted: 10/09/2019] [Indexed: 01/03/2023]
Abstract
DNA mismatch repair (MMR) increases replication fidelity and genome stability by correcting DNA polymerase errors that remain after replication. Defects in MMR result in the accumulation of mutations and lead to human tumor development. Germline mutations in MMR cause the hereditary cancer syndrome, Lynch syndrome. After replication, DNA is reorganized into its chromatin structure and wrapped around histone octamers. DNA MMR is thought to be less efficient in recognizing and repairing mispairs packaged in chromatin, in which case MMR must either compete for access to naked DNA before histone deposition or actively move nucleosomes to access the mispair. This article reviews studies into the mechanistic and physical interactions between MMR and various chromatin-associated factors, including the histone deposition complex CAF1. Recent Xenopus and Saccharomyces cerevisiae studies describe a physical interaction between Msh2 and chromatin-remodeling ATPase Fun30/SMARCAD1, with potential mechanistic roles for SMARCAD1 in moving histones for both mispair access and excision tract elongation. The RSC complex, another histone remodeling complex, also potentially influences excision tract length. Deletion mutations of RSC2 point to mechanistic interactions with the MMR pathways. Together, these studies paint a picture of complex interactions between MMR and the chromatin environment that will require numerous additional genetic, biochemical, and cell biology experiments to fully understand. Understanding how these pathways interconnect is essential in fully understanding eukaryotic MMR and has numerous implications in human tumor formation and treatment.
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Affiliation(s)
- Eva M Goellner
- Department of Toxicology and Cancer Biology, Markey Cancer Center, University of Kentucky College of Medicine, Lexington, KY, 40536, USA.
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18
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Chakraborty U, Mackenroth B, Shalloway D, Alani E. Chromatin Modifiers Alter Recombination Between Divergent DNA Sequences. Genetics 2019; 212:1147-1162. [PMID: 31221666 PMCID: PMC6707472 DOI: 10.1534/genetics.119.302395] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 06/18/2019] [Indexed: 02/07/2023] Open
Abstract
Recombination between divergent DNA sequences is actively prevented by heteroduplex rejection mechanisms. In baker's yeast, such antirecombination mechanisms can be initiated by the recognition of DNA mismatches in heteroduplex DNA by MSH proteins, followed by recruitment of the Sgs1-Top3-Rmi1 helicase-topoisomerase complex to unwind the recombination intermediate. We previously showed that the repair/rejection decision during single-strand annealing recombination is temporally regulated by MSH (MutShomolog) protein levels and by factors that excise nonhomologous single-stranded tails. These observations, coupled with recent studies indicating that mismatch repair (MMR) factors interact with components of the histone chaperone machinery, encouraged us to explore roles for epigenetic factors and chromatin conformation in regulating the decision to reject vs. repair recombination between divergent DNA substrates. This work involved the use of an inverted repeat recombination assay thought to measure sister chromatid repair during DNA replication. Our observations are consistent with the histone chaperones CAF-1 and Rtt106, and the histone deacetylase Sir2, acting to suppress heteroduplex rejection and the Rpd3, Hst3, and Hst4 deacetylases acting to promote heteroduplex rejection. These observations, and double-mutant analysis, have led to a model in which nucleosomes located at DNA lesions stabilize recombination intermediates and compete with MMR factors that mediate heteroduplex rejection.
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Affiliation(s)
- Ujani Chakraborty
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14853-2703
| | - Beata Mackenroth
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14853-2703
| | - David Shalloway
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14853-2703
| | - Eric Alani
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14853-2703
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19
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Harkness TAA. Activating the Anaphase Promoting Complex to Enhance Genomic Stability and Prolong Lifespan. Int J Mol Sci 2018; 19:ijms19071888. [PMID: 29954095 PMCID: PMC6073722 DOI: 10.3390/ijms19071888] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 06/19/2018] [Accepted: 06/20/2018] [Indexed: 12/19/2022] Open
Abstract
In aging cells, genomic instability is now recognized as a hallmark event. Throughout life, cells encounter multiple endogenous and exogenous DNA damaging events that are mostly repaired, but inevitably DNA mutations, chromosome rearrangements, and epigenetic deregulation begins to mount. Now that people are living longer, more and more late life time is spent suffering from age-related disease, in which genomic instability plays a critical role. However, several major questions remain heavily debated, such as the following: When does aging start? How long can we live? In order to minimize the impact of genomic instability on longevity, it is important to understand when aging starts, and to ensure repair mechanisms remain optimal from the very start to the very end. In this review, the interplay between the stress and nutrient response networks, and the regulation of homeostasis and genomic stability, is discussed. Mechanisms that link these two networks are predicted to be key lifespan determinants. The Anaphase Promoting Complex (APC), a large evolutionarily conserved ubiquitin ligase, can potentially serve this need. Recent work demonstrates that the APC maintains genomic stability, mounts a stress response, and increases longevity in yeast. Furthermore, inhibition of APC activity by glucose and nutrient response factors indicates a tight link between the APC and the stress/nutrient response networks.
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Affiliation(s)
- Troy A A Harkness
- Department of Anatomy and Cell Biology, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada.
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20
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Nucleosomes around a mismatched base pair are excluded via an Msh2-dependent reaction with the aid of SNF2 family ATPase Smarcad1. Genes Dev 2018; 32:806-821. [PMID: 29899141 PMCID: PMC6049510 DOI: 10.1101/gad.310995.117] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 04/27/2018] [Indexed: 01/01/2023]
Abstract
Here, Terui et al. studied the mechanisms underlying chromatin remodeling that occurs during MMR. They show that the eukaryotic MMR system has an ability to exclude local nucleosomes and identify Smarcad1/Fun30 as an accessory factor for the MMR reaction. Post-replicative correction of replication errors by the mismatch repair (MMR) system is critical for suppression of mutations. Although the MMR system may need to handle nucleosomes at the site of chromatin replication, how MMR occurs in the chromatin environment remains unclear. Here, we show that nucleosomes are excluded from a >1-kb region surrounding a mismatched base pair in Xenopus egg extracts. The exclusion was dependent on the Msh2–Msh6 mismatch recognition complex but not the Mlh1-containing MutL homologs and counteracts both the HIRA- and CAF-1 (chromatin assembly factor 1)-mediated chromatin assembly pathways. We further found that the Smarcad1 chromatin remodeling ATPase is recruited to mismatch-carrying DNA in an Msh2-dependent but Mlh1-independent manner to assist nucleosome exclusion and that Smarcad1 facilitates the repair of mismatches when nucleosomes are preassembled on DNA. In budding yeast, deletion of FUN30, the homolog of Smarcad1, showed a synergistic increase of spontaneous mutations in combination with MSH6 or MSH3 deletion but no significant increase with MSH2 deletion. Genetic analyses also suggested that the function of Fun30 in MMR is to counteract CAF-1. Our study uncovers that the eukaryotic MMR system has an ability to exclude local nucleosomes and identifies Smarcad1/Fun30 as an accessory factor for the MMR reaction.
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21
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Kondratick CM, Litman JM, Shaffer KV, Washington MT, Dieckman LM. Crystal structures of PCNA mutant proteins defective in gene silencing suggest a novel interaction site on the front face of the PCNA ring. PLoS One 2018; 13:e0193333. [PMID: 29499038 PMCID: PMC5834165 DOI: 10.1371/journal.pone.0193333] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 02/08/2018] [Indexed: 11/19/2022] Open
Abstract
Proliferating cell nuclear antigen (PCNA), a homotrimeric protein, is the eukaryotic sliding clamp that functions as a processivity factor for polymerases during DNA replication. Chromatin association factor 1 (CAF-1) is a heterotrimeric histone chaperone protein that is required for coupling chromatin assembly with DNA replication in eukaryotes. CAF-1 association with replicating DNA, and the targeting of newly synthesized histones to sites of DNA replication and repair requires its interaction with PCNA. Genetic studies have identified three mutant forms of PCNA in yeast that cause defects in gene silencing and exhibit altered association of CAF-1 to chromatin in vivo, as well as inhibit binding to CAF-1 in vitro. Three of these mutant forms of PCNA, encoded by the pol30-6, pol30-8, and the pol30-79 alleles, direct the synthesis of PCNA proteins with the amino acid substitutions D41A/D42A, R61A/D63A, and L126A/I128A, respectively. Interestingly, these double alanine substitutions are located far away from each other within the PCNA protein. To understand the structural basis of the interaction between PCNA and CAF-1 and how disruption of this interaction leads to reduced gene silencing, we determined the X-ray crystal structures of each of these mutant PCNA proteins. All three of the substitutions caused disruptions of a surface cavity on the front face of the PCNA ring, which is formed in part by three loops comprised of residues 21–24, 41–44, and 118–134. We suggest that this cavity is a novel binding pocket required for the interaction between PCNA and CAF-1, and that this region in PCNA also represents a potential binding site for other PCNA-binding proteins.
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Affiliation(s)
- Christine M. Kondratick
- Department of Biochemistry, University of Iowa College of Medicine, Iowa City, IA, United States of America
| | - Jacob M. Litman
- Department of Biochemistry, University of Iowa College of Medicine, Iowa City, IA, United States of America
| | - Kurt V. Shaffer
- Department of Chemistry, Creighton University, Omaha, NE, United States of America
| | - M. Todd Washington
- Department of Biochemistry, University of Iowa College of Medicine, Iowa City, IA, United States of America
| | - Lynne M. Dieckman
- Department of Chemistry, Creighton University, Omaha, NE, United States of America
- * E-mail:
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22
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Dahal BK, Kadyrova LY, Delfino KR, Rogozin IB, Gujar V, Lobachev KS, Kadyrov FA. Involvement of DNA mismatch repair in the maintenance of heterochromatic DNA stability in Saccharomyces cerevisiae. PLoS Genet 2017; 13:e1007074. [PMID: 29069084 PMCID: PMC5673234 DOI: 10.1371/journal.pgen.1007074] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 11/06/2017] [Accepted: 10/15/2017] [Indexed: 11/30/2022] Open
Abstract
Heterochromatin contains a significant part of nuclear DNA. Little is known about the mechanisms that govern heterochromatic DNA stability. We show here that in the yeast Saccharomyces cerevisiae (i) DNA mismatch repair (MMR) is required for the maintenance of heterochromatic DNA stability, (ii) MutLα (Mlh1-Pms1 heterodimer), MutSα (Msh2-Msh6 heterodimer), MutSβ (Msh2-Msh3 heterodimer), and Exo1 are involved in MMR at heterochromatin, (iii) Exo1-independent MMR at heterochromatin frequently leads to the formation of Pol ζ-dependent mutations, (iv) MMR cooperates with the proofreading activity of Pol ε and the histone acetyltransferase Rtt109 in the maintenance of heterochromatic DNA stability, (v) repair of base-base mismatches at heterochromatin is less efficient than repair of base-base mismatches at euchromatin, and (vi) the efficiency of repair of 1-nt insertion/deletion loops at heterochromatin is similar to the efficiency of repair of 1-nt insertion/deletion loops at euchromatin. Eukaryotic mismatch repair is an important intracellular process that defends DNA against mutations. Inactivation of mismatch repair in human cells strongly increases the risk of cancer initiation and development. Although significant progress has been made in understanding mismatch repair at euchromatin, mismatch repair at heterochromatin is not well understood. Baker’s yeast is a key model organism to study mismatch repair. We determined that in baker’s yeast (1) mismatch repair protects heterochromatic DNA from mutations, (2) the MutLα, MutSα, MutSβ, and Exo1 proteins play important roles in mismatch repair at heterochromatin, (3) Exo1-independent mismatch repair at heterochromatin is an error-prone process; (4) mismatch repair cooperates with two other intracellular processes to protect the stability of heterochromatic DNA; and (5) the efficiency of repair of base-base mismatches at heterochromatin is lower than the efficiency of repair of base-base mismatches at euchromatin, but the efficiency of 1-nt insertion/deletion loop repair at heterochromatin is similar to the efficiency of 1-nt insertion/deletion loop repair at euchromatin.
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Affiliation(s)
- Basanta K. Dahal
- Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale, IL, United States of America
| | - Lyudmila Y. Kadyrova
- Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale, IL, United States of America
| | - Kristin R. Delfino
- Center for Clinical Research, Southern Illinois University School of Medicine, Springfield, IL, United States of America
| | - Igor B. Rogozin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD, United States of America
| | - Vaibhavi Gujar
- Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale, IL, United States of America
| | - Kirill S. Lobachev
- School of Biological Sciences and Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, United States of America
| | - Farid A. Kadyrov
- Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale, IL, United States of America
- * E-mail:
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23
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Kadyrova LY, Dahal BK, Kadyrov FA. The Major Replicative Histone Chaperone CAF-1 Suppresses the Activity of the DNA Mismatch Repair System in the Cytotoxic Response to a DNA-methylating Agent. J Biol Chem 2016; 291:27298-27312. [PMID: 27872185 DOI: 10.1074/jbc.m116.760561] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 11/15/2016] [Indexed: 11/06/2022] Open
Abstract
The DNA mismatch repair (MMR) system corrects DNA mismatches in the genome. It is also required for the cytotoxic response of O6-methylguanine-DNA methyltransferase (MGMT)-deficient mammalian cells and yeast mgt1Δ rad52Δ cells to treatment with Sn1-type methylating agents, which produce cytotoxic O6-methylguanine (O6-mG) DNA lesions. Specifically, an activity of the MMR system causes degradation of irreparable O6-mG-T mispair-containing DNA, triggering cell death; this process forms the basis of treatments of MGMT-deficient cancers with Sn1-type methylating drugs. Recent research supports the view that degradation of irreparable O6-mG-T mispair-containing DNA by the MMR system and CAF-1-dependent packaging of the newly replicated DNA into nucleosomes are two concomitant processes that interact with each other. Here, we studied whether CAF-1 modulates the activity of the MMR system in the cytotoxic response to Sn1-type methylating agents. We found that CAF-1 suppresses the activity of the MMR system in the cytotoxic response of yeast mgt1Δ rad52Δ cells to the prototypic Sn1-type methylating agent N-methyl-N'-nitro-N-nitrosoguanidine. We also report evidence that in human MGMT-deficient cell-free extracts, CAF-1-dependent packaging of irreparable O6-mG-T mispair-containing DNA into nucleosomes suppresses its degradation by the MMR system. Taken together, these findings suggest that CAF-1-dependent incorporation of irreparable O6-mG-T mispair-containing DNA into nucleosomes suppresses its degradation by the MMR system, thereby defending the cell against killing by the Sn1-type methylating agent.
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Affiliation(s)
- Lyudmila Y Kadyrova
- From the Department of Biochemistry and Molecular Biology, Southern Illinois University, School of Medicine, Carbondale, Illinois 62901
| | - Basanta K Dahal
- From the Department of Biochemistry and Molecular Biology, Southern Illinois University, School of Medicine, Carbondale, Illinois 62901
| | - Farid A Kadyrov
- From the Department of Biochemistry and Molecular Biology, Southern Illinois University, School of Medicine, Carbondale, Illinois 62901
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24
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Yang C, Sengupta S, Hegde PM, Mitra J, Jiang S, Holey B, Sarker AH, Tsai MS, Hegde ML, Mitra S. Regulation of oxidized base damage repair by chromatin assembly factor 1 subunit A. Nucleic Acids Res 2016; 45:739-748. [PMID: 27794043 PMCID: PMC5314755 DOI: 10.1093/nar/gkw1024] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 10/13/2016] [Accepted: 10/19/2016] [Indexed: 01/27/2023] Open
Abstract
Reactive oxygen species (ROS), generated both endogenously and in response to exogenous stress, induce point mutations by mis-replication of oxidized bases and other lesions in the genome. Repair of these lesions via base excision repair (BER) pathway maintains genomic fidelity. Regulation of the BER pathway for mutagenic oxidized bases, initiated by NEIL1 and other DNA glycosylases at the chromatin level remains unexplored. Whether single nucleotide (SN)-BER of a damaged base requires histone deposition or nucleosome remodeling is unknown, unlike nucleosome reassembly which is shown to be required for other DNA repair processes. Here we show that chromatin assembly factor (CAF)-1 subunit A (CHAF1A), the p150 subunit of the histone H3/H4 chaperone, and its partner anti-silencing function protein 1A (ASF1A), which we identified in human NEIL1 immunoprecipitation complex, transiently dissociate from chromatin bound NEIL1 complex in G1 cells after induction of oxidative base damage. CHAF1A inhibits NEIL1 initiated repair in vitro. Subsequent restoration of the chaperone-BER complex in cell, presumably after completion of repair, suggests that histone chaperones sequester the repair complex for oxidized bases in non-replicating chromatin, and allow repair when oxidized bases are induced in the genome.
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Affiliation(s)
- Chunying Yang
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX 77030, USA
| | - Shiladitya Sengupta
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX 77030, USA .,Weill Cornell Medical College, Cornell University, New York, NY 10065, USA
| | - Pavana M Hegde
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX 77030, USA
| | - Joy Mitra
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX 77030, USA
| | - Shuai Jiang
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Brooke Holey
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Altaf H Sarker
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Miaw-Sheue Tsai
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Muralidhar L Hegde
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX 77030, USA.,Weill Cornell Medical College, Cornell University, New York, NY 10065, USA.,Houston Methodist Neurological Institute, Houston, TX 77030, USA
| | - Sankar Mitra
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX 77030, USA .,Weill Cornell Medical College, Cornell University, New York, NY 10065, USA
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25
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Chakraborty U, Alani E. Understanding how mismatch repair proteins participate in the repair/anti-recombination decision. FEMS Yeast Res 2016; 16:fow071. [PMID: 27573382 PMCID: PMC5976031 DOI: 10.1093/femsyr/fow071] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 06/24/2016] [Accepted: 08/24/2016] [Indexed: 01/06/2023] Open
Abstract
Mismatch repair (MMR) systems correct DNA mismatches that result from DNA polymerase misincorporation errors. Mismatches also appear in heteroduplex DNA intermediates formed during recombination between nearly identical sequences, and can be corrected by MMR or removed through an unwinding mechanism, known as anti-recombination or heteroduplex rejection. We review studies, primarily in baker's yeast, which support how specific factors can regulate the MMR/anti-recombination decision. Based on recent advances, we present models for how DNA structure, relative amounts of key repair proteins, the timely localization of repair proteins to DNA substrates and epigenetic marks can modulate this critical decision.
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Affiliation(s)
- Ujani Chakraborty
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853-2703, USA
| | - Eric Alani
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853-2703, USA
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