1
|
Ahmed SMQ, Sasikumar J, Laha S, Das SP. Multifaceted role of the DNA replication protein MCM10 in maintaining genome stability and its implication in human diseases. Cancer Metastasis Rev 2024:10.1007/s10555-024-10209-3. [PMID: 39240414 DOI: 10.1007/s10555-024-10209-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Accepted: 08/29/2024] [Indexed: 09/07/2024]
Abstract
MCM10 plays a vital role in genome duplication and is crucial for DNA replication initiation, elongation, and termination. It coordinates several proteins to assemble at the fork, form a functional replisome, trigger origin unwinding, and stabilize the replication bubble. MCM10 overexpression is associated with increased aggressiveness in breast, cervical, and several other cancers. Disruption of MCM10 leads to altered replication timing associated with initiation site gains and losses accompanied by genome instability. Knockdown of MCM10 affects the proliferation and migration of cancer cells, manifested by DNA damage and replication fork arrest, and has recently been shown to be associated with clinical conditions like CNKD and RCM. Loss of MCM10 function is associated with impaired telomerase activity, leading to the accumulation of abnormal replication forks and compromised telomere length. MCM10 interacts with histones, aids in nucleosome assembly, binds BRCA2 to maintain genome integrity during DNA damage, prevents lesion skipping, and inhibits PRIMPOL-mediated repriming. It also interacts with the fork reversal enzyme SMARCAL1 and inhibits fork regression. Additionally, MCM10 undergoes several post-translational modifications and contributes to transcriptional silencing by interacting with the SIR proteins. This review explores the mechanism associated with MCM10's multifaceted role in DNA replication initiation, chromatin organization, transcriptional silencing, replication stress, fork stability, telomere length maintenance, and DNA damage response. Finally, we discuss the role of MCM10 in the early detection of cancer, its prognostic significance, and its potential use in therapeutics for cancer treatment.
Collapse
Affiliation(s)
- Sumayyah M Q Ahmed
- Cell Biology and Molecular Genetics (CBMG), Yenepoya Research Centre (YRC), Yenepoya (Deemed to be University), Mangalore, 575018, India
| | - Jayaprakash Sasikumar
- Cell Biology and Molecular Genetics (CBMG), Yenepoya Research Centre (YRC), Yenepoya (Deemed to be University), Mangalore, 575018, India
| | - Suparna Laha
- Cell Biology and Molecular Genetics (CBMG), Yenepoya Research Centre (YRC), Yenepoya (Deemed to be University), Mangalore, 575018, India
| | - Shankar Prasad Das
- Cell Biology and Molecular Genetics (CBMG), Yenepoya Research Centre (YRC), Yenepoya (Deemed to be University), Mangalore, 575018, India.
| |
Collapse
|
2
|
Schmit MM, Baxley RM, Wang L, Hinderlie P, Kaufman M, Simon E, Raju A, Miller JS, Bielinsky AK. A critical threshold of MCM10 is required to maintain genome stability during differentiation of induced pluripotent stem cells into natural killer cells. Open Biol 2024; 14:230407. [PMID: 38262603 PMCID: PMC10805602 DOI: 10.1098/rsob.230407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 11/23/2023] [Indexed: 01/25/2024] Open
Abstract
Natural killer (NK) cell deficiency (NKD) is a rare disease in which NK cell function is reduced, leaving affected individuals susceptible to repeated viral infections and cancer. Recently, a patient with NKD was identified carrying compound heterozygous variants of MCM10 (minichromosome maintenance protein 10), an essential gene required for DNA replication, that caused a significant decrease in the amount of functional MCM10. NKD in this patient presented as loss of functionally mature late-stage NK cells. To understand how MCM10 deficiency affects NK cell development, we generated MCM10 heterozygous (MCM10+/-) induced pluripotent stem cell (iPSC) lines. Analyses of these cell lines demonstrated that MCM10 was haploinsufficient, similar to results in other human cell lines. Reduced levels of MCM10 in mutant iPSCs was associated with impaired clonogenic survival and increased genomic instability, including micronuclei formation and telomere erosion. The severity of these phenotypes correlated with the extent of MCM10 depletion. Significantly, MCM10+/- iPSCs displayed defects in NK cell differentiation, exhibiting reduced yields of hematopoietic stem cells (HSCs). Although MCM10+/- HSCs were able to give rise to lymphoid progenitors, these did not generate mature NK cells. The lack of mature NK cells coincided with telomere erosion, suggesting that NKD caused by these MCM10 variants arose from the accumulation of genomic instability including degradation of chromosome ends.
Collapse
Affiliation(s)
- Megan M. Schmit
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Ryan M. Baxley
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Liangjun Wang
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Peter Hinderlie
- Division of Hematology, Oncology and Transplantation, University of Minnesota, Minneapolis, MN, USA
| | - Marissa Kaufman
- Division of Hematology, Oncology and Transplantation, University of Minnesota, Minneapolis, MN, USA
| | - Emily Simon
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Anjali Raju
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Jeffrey S. Miller
- Division of Hematology, Oncology and Transplantation, University of Minnesota, Minneapolis, MN, USA
| | - Anja-Katrin Bielinsky
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, USA
| |
Collapse
|
3
|
Zhao X, Wang J, Jin D, Cheng J, Chen H, Li Z, Wang Y, Lou H, Zhu JK, Du X, Gong Z. AtMCM10 promotes DNA replication-coupled nucleosome assembly in Arabidopsis. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2023; 65:203-222. [PMID: 36541721 DOI: 10.1111/jipb.13438] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 12/19/2022] [Indexed: 06/17/2023]
Abstract
Minichromosome Maintenance protein 10 (MCM10) is essential for DNA replication initiation and DNA elongation in yeasts and animals. Although the functions of MCM10 in DNA replication and repair have been well documented, the detailed mechanisms for MCM10 in these processes are not well known. Here, we identified AtMCM10 gene through a forward genetic screening for releasing a silenced marker gene. Although plant MCM10 possesses a similar crystal structure as animal MCM10, AtMCM10 is not essential for plant growth or development in Arabidopsis. AtMCM10 can directly bind to histone H3-H4 and promotes nucleosome assembly in vitro. The nucleosome density is decreased in Atmcm10, and most of the nucleosome density decreased regions in Atmcm10 are also regulated by newly synthesized histone chaperone Chromatin Assembly Factor-1 (CAF-1). Loss of both AtMCM10 and CAF-1 is embryo lethal, indicating that AtMCM10 and CAF-1 are indispensable for replication-coupled nucleosome assembly. AtMCM10 interacts with both new and parental histones. Atmcm10 mutants have lower H3.1 abundance and reduced H3K27me1/3 levels with releasing some silenced transposons. We propose that AtMCM10 deposits new and parental histones during nucleosome assembly, maintaining proper epigenetic modifications and genome stability during DNA replication.
Collapse
Affiliation(s)
- Xinjie Zhao
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Jingyi Wang
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, The Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Dan Jin
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Jinkui Cheng
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Hui Chen
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Zhen Li
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Yu Wang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Huiqiang Lou
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Jian-Kang Zhu
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, School of Life Science, Department of Biology, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Xuan Du
- Department of Biochemistry and Molecular Biology, International Cancer Center, Shenzhen University Medical School, Shenzhen, 518060, China
- Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, National-Regional Key Technology Engineering Laboratory for Medical Ultrasound, School of Biomedical Engineering, Shenzhen University Medical School, Shenzhen, 518060, China
| | - Zhizhong Gong
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
- School of Life Science, Institute of Life Science and Green Development, Hebei University, Baoding, 071002, China
| |
Collapse
|
4
|
Perera HM, Behrmann MS, Hoang JM, Griffin WC, Trakselis MA. Contacts and context that regulate DNA helicase unwinding and replisome progression. Enzymes 2019; 45:183-223. [PMID: 31627877 DOI: 10.1016/bs.enz.2019.08.001] [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] [Indexed: 12/15/2022]
Abstract
Hexameric DNA helicases involved in the separation of duplex DNA at the replication fork have a universal architecture but have evolved from two separate protein families. The consequences are that the regulation, translocation polarity, strand specificity, and architectural orientation varies between phage/bacteria to that of archaea/eukaryotes. Once assembled and activated for single strand DNA translocation and unwinding, the DNA polymerase couples tightly to the helicase forming a robust replisome complex. However, this helicase-polymerase interaction can be challenged by various forms of endogenous or exogenous agents that can stall the entire replisome or decouple DNA unwinding from synthesis. The consequences of decoupling can be severe, leading to a build-up of ssDNA requiring various pathways for replication fork restart. All told, the hexameric helicase sits prominently at the front of the replisome constantly responding to a variety of obstacles that require transient unwinding/reannealing, traversal of more stable blocks, and alternations in DNA unwinding speed that regulate replisome progression.
Collapse
Affiliation(s)
- Himasha M Perera
- Department of Chemistry and Biochemistry, Baylor University, Waco, TX, United States
| | - Megan S Behrmann
- Department of Chemistry and Biochemistry, Baylor University, Waco, TX, United States
| | - Joy M Hoang
- Department of Chemistry and Biochemistry, Baylor University, Waco, TX, United States
| | - Wezley C Griffin
- Department of Chemistry and Biochemistry, Baylor University, Waco, TX, United States
| | - Michael A Trakselis
- Department of Chemistry and Biochemistry, Baylor University, Waco, TX, United States.
| |
Collapse
|
5
|
Wu R, Amin A, Wang Z, Huang Y, Man-Hei Cheung M, Yu Z, Yang W, Liang C. The interaction networks of the budding yeast and human DNA replication-initiation proteins. Cell Cycle 2019; 18:723-741. [PMID: 30890025 DOI: 10.1080/15384101.2019.1586509] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
DNA replication is a stringently regulated cellular process. In proliferating cells, DNA replication-initiation proteins (RIPs) are sequentially loaded onto replication origins during the M-to-G1 transition to form the pre-replicative complex (pre-RC), a process known as replication licensing. Subsequently, additional RIPs are recruited to form the pre-initiation complex (pre-IC). RIPs and their regulators ensure that chromosomal DNA is replicated exactly once per cell cycle. Origin recognition complex (ORC) binds to, and marks replication origins throughout the cell cycle and recruits other RIPs including Noc3p, Ipi1-3p, Cdt1p, Cdc6p and Mcm2-7p to form the pre-RC. The detailed mechanisms and regulation of the pre-RC and its exact architecture still remain unclear. In this study, pairwise protein-protein interactions among 23 budding yeast and 16 human RIPs were systematically and comprehensively examined by yeast two-hybrid analysis. This study tested 470 pairs of yeast and 196 pairs of human RIPs, from which 113 and 96 positive interactions, respectively, were identified. While many of these interactions were previously reported, some were novel, including various ORC and MCM subunit interactions, ORC self-interactions, and the interactions of IPI3 and NOC3 with several pre-RC and pre-IC proteins. Ten of the novel interactions were further confirmed by co-immunoprecipitation assays. Furthermore, we identified the conserved interaction networks between the yeast and human RIPs. This study provides a foundation and framework for further understanding the architectures, interactions and functions of the yeast and human pre-RC and pre-IC.
Collapse
Affiliation(s)
- Rentian Wu
- a Division of Life Science, Center for Cancer Research and State Key Lab for Molecular Neuroscience , Hong Kong University of Science and Technology , Hong Kong , China.,b Guangzhou HKUST Fok Ying Tung Research Institute , Guangzhou , China
| | - Aftab Amin
- a Division of Life Science, Center for Cancer Research and State Key Lab for Molecular Neuroscience , Hong Kong University of Science and Technology , Hong Kong , China.,b Guangzhou HKUST Fok Ying Tung Research Institute , Guangzhou , China.,c School of Chinese Medicine , Hong Kong Baptist University , Guangzhou , China
| | - Ziyi Wang
- a Division of Life Science, Center for Cancer Research and State Key Lab for Molecular Neuroscience , Hong Kong University of Science and Technology , Hong Kong , China
| | - Yining Huang
- a Division of Life Science, Center for Cancer Research and State Key Lab for Molecular Neuroscience , Hong Kong University of Science and Technology , Hong Kong , China
| | - Marco Man-Hei Cheung
- a Division of Life Science, Center for Cancer Research and State Key Lab for Molecular Neuroscience , Hong Kong University of Science and Technology , Hong Kong , China.,b Guangzhou HKUST Fok Ying Tung Research Institute , Guangzhou , China
| | - Zhiling Yu
- c School of Chinese Medicine , Hong Kong Baptist University , Guangzhou , China
| | - Wei Yang
- a Division of Life Science, Center for Cancer Research and State Key Lab for Molecular Neuroscience , Hong Kong University of Science and Technology , Hong Kong , China.,d Guangdong Lewwin Pharmaceutical Research Institute Co., Ltd , Hong Kong , China
| | - Chun Liang
- a Division of Life Science, Center for Cancer Research and State Key Lab for Molecular Neuroscience , Hong Kong University of Science and Technology , Hong Kong , China.,b Guangzhou HKUST Fok Ying Tung Research Institute , Guangzhou , China.,e ntelgen Limited , Hong Kong-Guangzhou-Foshan , China
| |
Collapse
|
6
|
Mcm10 has potent strand-annealing activity and limits translocase-mediated fork regression. Proc Natl Acad Sci U S A 2018; 116:798-803. [PMID: 30598452 PMCID: PMC6338834 DOI: 10.1073/pnas.1819107116] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Fork regression is a way of circumventing or dealing with DNA lesions and is important to genome integrity. Fork regression is performed by double-strand DNA ATPases that initially cause newly synthesized strands to unpair from the parental strands, followed by pairing of the new strands and reversal of the fork. This study shows that Mcm10, an essential replication factor, efficiently anneals complementary strands and also inhibits fork regression by SMARCAL1. Moreover, the study localizes the Mcm10 DNA-binding domain to the N-terminal domains of the replicative CMG helicase at the forked nexus. Thus, forks that are unimpeded would contain Mcm10 at a strategic position where its DNA-binding and/or annealing function may block fork regression enzymes and thereby protect active forks from becoming reversed. The 11-subunit eukaryotic replicative helicase CMG (Cdc45, Mcm2-7, GINS) tightly binds Mcm10, an essential replication protein in all eukaryotes. Here we show that Mcm10 has a potent strand-annealing activity both alone and in complex with CMG. CMG-Mcm10 unwinds and then reanneals single strands soon after they have been unwound in vitro. Given the DNA damage and replisome instability associated with loss of Mcm10 function, we examined the effect of Mcm10 on fork regression. Fork regression requires the unwinding and pairing of newly synthesized strands, performed by a specialized class of ATP-dependent DNA translocases. We show here that Mcm10 inhibits fork regression by the well-known fork reversal enzyme SMARCAL1. We propose that Mcm10 inhibits the unwinding of nascent strands to prevent fork regression at normal unperturbed replication forks, either by binding the fork junction to form a block to SMARCAL1 or by reannealing unwound nascent strands to their parental template. Analysis of the CMG-Mcm10 complex by cross-linking mass spectrometry reveals Mcm10 interacts with six CMG subunits, with the DNA-binding region of Mcm10 on the N-face of CMG. This position on CMG places Mcm10 at the fork junction, consistent with a role in regulating fork regression.
Collapse
|
7
|
Zhang J, Geng Y, Guo F, Zhang F, Liu M, Song L, Ma Y, Li D, Zhang Y, Xu H, Yang H. Screening and identification of critical transcription factors involved in the protection of cardiomyocytes against hydrogen peroxide-induced damage by Yixin-shu. Sci Rep 2017; 7:13867. [PMID: 29066842 PMCID: PMC5655617 DOI: 10.1038/s41598-017-10131-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Accepted: 08/04/2017] [Indexed: 01/12/2023] Open
Abstract
Oxidative stress initiates harmful cellular responses, such as DNA damage and protein denaturation, triggering a series of cardiovascular disorders. Systematic investigations of the transcription factors (TFs) involved in oxidative stress can help reveal the underlying molecular mechanisms and facilitate the discovery of effective therapeutic targets in related diseases. In this study, an integrated strategy which integrated RNA-seq-based transcriptomics techniques and a newly developed concatenated tandem array of consensus TF response elements (catTFREs)-based proteomics approach and then combined with a network pharmacology analysis, was developed and this integrated strategy was used to investigate critical TFs in the protection of Yixin-shu (YXS), a standardized medical product used for ischaemic heart disease, against hydrogen peroxide (H2O2)-induced damage in cardiomyocytes. Importantly, YXS initiated biological process such as anti-apoptosis and DNA repair to protect cardiomyocytes from H2O2-induced damage. By using the integrated strategy, DNA-(apurinic or apyrimidinic site) lyase (Apex1), pre B-cell leukemia transcription factor 3 (Pbx3), and five other TFs with their functions involved in anti-oxidation, anti-apoptosis and DNA repair were identified. This study offers a new understanding of the mechanism underlying YXS-mediated protection against H2O2-induced oxidative stress in cardiomyocytes and reveals novel targets for oxidative stress-related diseases.
Collapse
Affiliation(s)
- Jingjing Zhang
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Ya Geng
- College of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan, 250355, China
| | - Feifei Guo
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Fangbo Zhang
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Mingwei Liu
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Radiation Medicine, Beijing, 102206, China
| | - Lei Song
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Radiation Medicine, Beijing, 102206, China
| | - Yuexiang Ma
- College of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan, 250355, China
| | - Defeng Li
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Yi Zhang
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Haiyu Xu
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China.
| | - Hongjun Yang
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China.
| |
Collapse
|
8
|
Perez-Arnaiz P, Bruck I, Colbert MK, Kaplan DL. An intact Mcm10 coiled-coil interaction surface is important for origin melting, helicase assembly and the recruitment of Pol-α to Mcm2-7. Nucleic Acids Res 2017; 45:7261-7275. [PMID: 28510759 PMCID: PMC5499591 DOI: 10.1093/nar/gkx438] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 05/03/2017] [Indexed: 11/16/2022] Open
Abstract
Mcm10 is an essential eukaryotic factor required for DNA replication. The replication fork helicase is composed of Cdc45, Mcm2–7 and GINS (CMG). DDK is an S-phase-specific kinase required for replication initiation, and the DNA primase-polymerase in eukaryotes is pol α. Mcm10 forms oligomers in vitro, mediated by the coiled-coil domain at the N-terminal region of the protein. We characterized an Mcm10 mutant at the N-terminal Domain (NTD), Mcm10-4A, defective for self-interaction. We found that the Mcm10-4A mutant was defective for stimulating DDK phosphorylation of Mcm2, binding to eighty-nucleotide ssDNA, and recruiting pol α to Mcm2–7 in vitro. Expression of wild-type levels of mcm10-4A resulted in severe growth and DNA replication defects in budding yeast cells, with diminished DDK phosphorylation of Mcm2. We then expressed the mcm10-4A in mcm5-bob1 mutant cells to bypass the defects mediated by diminished stimulation of DDK phosphorylation of Mcm2. Expression of wild-type levels of mcm10-4A in mcm5-bob1 mutant cells resulted in severe growth and DNA replication defects, along with diminished RPA signal at replication origins. We also detected diminished GINS and pol-α recruitment to the Mcm2–7 complex. We conclude that an intact Mcm10 coiled-coil interaction surface is important for origin melting, helicase assembly, and the recruitment of pol α to Mcm2–7.
Collapse
Affiliation(s)
- Patricia Perez-Arnaiz
- Florida State University College of Medicine, Department of Biomedical Sciences, Tallahassee, FL 32306, USA
| | - Irina Bruck
- Florida State University College of Medicine, Department of Biomedical Sciences, Tallahassee, FL 32306, USA
| | - Max K Colbert
- Florida State University College of Medicine, Department of Biomedical Sciences, Tallahassee, FL 32306, USA
| | - Daniel L Kaplan
- Florida State University College of Medicine, Department of Biomedical Sciences, Tallahassee, FL 32306, USA
| |
Collapse
|
9
|
Neves H, Kwok HF. In sickness and in health: The many roles of the minichromosome maintenance proteins. Biochim Biophys Acta Rev Cancer 2017; 1868:295-308. [DOI: 10.1016/j.bbcan.2017.06.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 05/29/2017] [Accepted: 06/01/2017] [Indexed: 01/09/2023]
|
10
|
Izumi M, Mizuno T, Yanagi KI, Sugimura K, Okumura K, Imamoto N, Abe T, Hanaoka F. The Mcm2-7-interacting domain of human mini-chromosome maintenance 10 (Mcm10) protein is important for stable chromatin association and origin firing. J Biol Chem 2017. [PMID: 28646110 DOI: 10.1074/jbc.m117.779371] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The protein mini-chromosome maintenance 10 (Mcm10) was originally identified as an essential yeast protein in the maintenance of mini-chromosome plasmids. Subsequently, Mcm10 has been shown to be required for both initiation and elongation during chromosomal DNA replication. However, it is not fully understood how the multiple functions of Mcm10 are coordinated or how Mcm10 interacts with other factors at replication forks. Here, we identified and characterized the Mcm2-7-interacting domain in human Mcm10. The interaction with Mcm2-7 required the Mcm10 domain that contained amino acids 530-655, which overlapped with the domain required for the stable retention of Mcm10 on chromatin. Expression of truncated Mcm10 in HeLa cells depleted of endogenous Mcm10 via siRNA revealed that the Mcm10 conserved domain (amino acids 200-482) is essential for DNA replication, whereas both the conserved and the Mcm2-7-binding domains were required for its full activity. Mcm10 depletion reduced the initiation frequency of DNA replication and interfered with chromatin loading of replication protein A, DNA polymerase (Pol) α, and proliferating cell nuclear antigen, whereas the chromatin loading of Cdc45 and Pol ϵ was unaffected. These results suggest that human Mcm10 is bound to chromatin through the interaction with Mcm2-7 and is primarily involved in the initiation of DNA replication after loading of Cdc45 and Pol ϵ.
Collapse
Affiliation(s)
- Masako Izumi
- Accelerator Applications Research Group, Nishina Center for Accelerator-Based Science, Wako, Saitama 351-0198, Japan.
| | - Takeshi Mizuno
- Cellular Dynamics Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
| | | | - Kazuto Sugimura
- Department of Life Science, Graduate School of Bioresources, Mie University, Tsu, Mie 514-8507, Japan
| | - Katsuzumi Okumura
- Department of Life Science, Graduate School of Bioresources, Mie University, Tsu, Mie 514-8507, Japan
| | - Naoko Imamoto
- Cellular Dynamics Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
| | - Tomoko Abe
- Accelerator Applications Research Group, Nishina Center for Accelerator-Based Science, Wako, Saitama 351-0198, Japan
| | - Fumio Hanaoka
- Department of Life Science, Faculty of Science, Gakushuin University, Tokyo 171-8588, Japan; Life Science Center of Tsukuba Advanced Research Alliance, University of Tsukuba, Ibaraki 305-8577, Japan
| |
Collapse
|
11
|
Mcm10: A Dynamic Scaffold at Eukaryotic Replication Forks. Genes (Basel) 2017; 8:genes8020073. [PMID: 28218679 PMCID: PMC5333062 DOI: 10.3390/genes8020073] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 02/09/2017] [Accepted: 02/09/2017] [Indexed: 12/13/2022] Open
Abstract
To complete the duplication of large genomes efficiently, mechanisms have evolved that coordinate DNA unwinding with DNA synthesis and provide quality control measures prior to cell division. Minichromosome maintenance protein 10 (Mcm10) is a conserved component of the eukaryotic replisome that contributes to this process in multiple ways. Mcm10 promotes the initiation of DNA replication through direct interactions with the cell division cycle 45 (Cdc45)-minichromosome maintenance complex proteins 2-7 (Mcm2-7)-go-ichi-ni-san GINS complex proteins, as well as single- and double-stranded DNA. After origin firing, Mcm10 controls replication fork stability to support elongation, primarily facilitating Okazaki fragment synthesis through recruitment of DNA polymerase-α and proliferating cell nuclear antigen. Based on its multivalent properties, Mcm10 serves as an essential scaffold to promote DNA replication and guard against replication stress. Under pathological conditions, Mcm10 is often dysregulated. Genetic amplification and/or overexpression of MCM10 are common in cancer, and can serve as a strong prognostic marker of poor survival. These findings are compatible with a heightened requirement for Mcm10 in transformed cells to overcome limitations for DNA replication dictated by altered cell cycle control. In this review, we highlight advances in our understanding of when, where and how Mcm10 functions within the replisome to protect against barriers that cause incomplete replication.
Collapse
|
12
|
Wang AB, Zhang YV, Tumbar T. Gata6 promotes hair follicle progenitor cell renewal by genome maintenance during proliferation. EMBO J 2016; 36:61-78. [PMID: 27908934 DOI: 10.15252/embj.201694572] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2016] [Revised: 09/30/2016] [Accepted: 10/28/2016] [Indexed: 01/29/2023] Open
Abstract
Cell proliferation is essential to rapid tissue growth and repair, but can result in replication-associated genome damage. Here, we implicate the transcription factor Gata6 in adult mouse hair follicle regeneration where it controls the renewal of rapidly proliferating epithelial (matrix) progenitors and hence the extent of production of terminally differentiated lineages. We find that Gata6 protects against DNA damage associated with proliferation, thus preventing cell cycle arrest and apoptosis. Furthermore, we show that in vivo Gata6 stimulates EDA-receptor signaling adaptor Edaradd level and NF-κB pathway activation, known to be important for DNA damage repair and stress response in general and for hair follicle growth in particular. In cultured keratinocytes, Edaradd rescues DNA damage, cell survival, and proliferation of Gata6 knockout cells and restores MCM10 expression. Our data add to recent evidence in embryonic stem and neural progenitor cells, suggesting a model whereby developmentally regulated transcription factors protect from DNA damage associated with proliferation at key stages of rapid tissue growth. Our data may add to understanding why Gata6 is a frequent target of amplification in cancers.
Collapse
Affiliation(s)
- Alex B Wang
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| | - Ying V Zhang
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| | - Tudorita Tumbar
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| |
Collapse
|
13
|
Zhang T, Fultz BL, Das-Bradoo S, Bielinsky AK. Mapping ubiquitination sites of S. cerevisiae Mcm10. Biochem Biophys Rep 2016; 8:212-218. [PMID: 28497125 PMCID: PMC5421568 DOI: 10.1016/j.bbrep.2016.09.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Minichromosome maintenance protein (Mcm) 10 is a part of the eukaryotic replication machinery and highly conserved throughout evolution. As a multivalent DNA scaffold, Mcm10 coordinates the action of proteins that are indispensable for lagging strand synthesis, such as the replication clamp, proliferating cell nuclear antigen (PCNA). The binding between Mcm10 and PCNA serves an essential function during DNA elongation and is mediated by the ubiquitination of Mcm10. Here we map lysine 372 as the primary attachment site for ubiquitin on S. cerevisiae Mcm10. Moreover, we identify five additional lysines that can be ubiquitinated. Mutation of lysine 372 to arginine ablates ubiquitination of overexpressed protein and causes sensitivity to the replication inhibitor hydroxyurea in cells that are S-phase checkpoint compromised. Together, these findings reveal the high selectivity of the ubiquitination machinery that targets Mcm10 and that ubiquitination has a role in suppressing replication stress. S. cerevisiae Mcm10 is ubiquitinated at lysine 372. Alternative ubiquitination sites exist at five specific lysine residues. The mcm10-K372R mutation synergizes with a 9-1-1 checkpoint deficiency.
Collapse
Affiliation(s)
- Tianji Zhang
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, 55455, United States of America
| | - Brandy L Fultz
- Department of Natural Sciences, College of Science and Health Professions, Northeastern State University, 3100 East New Orleans Street, Broken Arrow, OK 74014
| | - Sapna Das-Bradoo
- Department of Natural Sciences, College of Science and Health Professions, Northeastern State University, 3100 East New Orleans Street, Broken Arrow, OK 74014
| | - Anja-Katrin Bielinsky
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, 55455, United States of America
| |
Collapse
|
14
|
Chadha GS, Gambus A, Gillespie PJ, Blow JJ. Xenopus Mcm10 is a CDK-substrate required for replication fork stability. Cell Cycle 2016; 15:2183-2195. [PMID: 27327991 PMCID: PMC4993430 DOI: 10.1080/15384101.2016.1199305] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 06/01/2016] [Accepted: 06/03/2016] [Indexed: 12/17/2022] Open
Abstract
During S phase, following activation of the S phase CDKs and the DBF4-dependent kinases (DDK), double hexamers of Mcm2-7 at licensed replication origins are activated to form the core replicative helicase. Mcm10 is one of several proteins that have been implicated from work in yeasts to play a role in forming a mature replisome during the initiation process. Mcm10 has also been proposed to play a role in promoting replisome stability after initiation has taken place. The role of Mcm10 is particularly unclear in metazoans, where conflicting data has been presented. Here, we investigate the role and regulation of Mcm10 in Xenopus egg extracts. We show that Xenopus Mcm10 is recruited to chromatin late in the process of replication initiation and this requires prior action of DDKs and CDKs. We also provide evidence that Mcm10 is a CDK substrate but does not need to be phosphorylated in order to associate with chromatin. We show that in extracts depleted of more than 99% of Mcm10, the bulk of DNA replication still occurs, suggesting that Mcm10 is not required for the process of replication initiation. However, in extracts depleted of Mcm10, the replication fork elongation rate is reduced. Furthermore, the absence of Mcm10 or its phosphorylation by CDK results in instability of replisome proteins on DNA, which is particularly important under conditions of replication stress.
Collapse
Affiliation(s)
- Gaganmeet Singh Chadha
- a Centre for Gene Regulation & Expression, School of Life Sciences, University of Dundee , Dundee , UK
| | - Agnieszka Gambus
- a Centre for Gene Regulation & Expression, School of Life Sciences, University of Dundee , Dundee , UK
| | - Peter J Gillespie
- a Centre for Gene Regulation & Expression, School of Life Sciences, University of Dundee , Dundee , UK
| | - J Julian Blow
- a Centre for Gene Regulation & Expression, School of Life Sciences, University of Dundee , Dundee , UK
| |
Collapse
|
15
|
Affiliation(s)
- Anja-Katrin Bielinsky
- a Department of Biochemistry , Molecular Biology, and Biophysics, University of Minnesota , Minneapolis , MN , USA
| |
Collapse
|
16
|
Damasceno JD, Obonaga R, Santos EV, Scott A, McCulloch R, Tosi LRO. Functional compartmentalization of Rad9 and Hus1 reveals diverse assembly of the 9-1-1 complex components during the DNA damage response in Leishmania. Mol Microbiol 2016; 101:1054-68. [PMID: 27301589 PMCID: PMC5453112 DOI: 10.1111/mmi.13441] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 05/17/2016] [Accepted: 06/11/2016] [Indexed: 01/22/2023]
Abstract
The Rad9‐Rad1‐Hus1 (9‐1‐1) complex is a key component in the coordination of DNA damage sensing, cell cycle progression and DNA repair pathways in eukaryotic cells. This PCNA‐related trimer is loaded onto RPA‐coated single stranded DNA and interacts with ATR kinase to mediate effective checkpoint signaling to halt the cell cycle and to promote DNA repair. Beyond these core activities, mounting evidence suggests that a broader range of functions can be provided by 9‐1‐1 structural diversification. The protozoan parasite Leishmania is an early‐branching eukaryote with a remarkably plastic genome, which hints at peculiar genome maintenance mechanisms. Here, we investigated the existence of homologs of the 9‐1‐1 complex subunits in L. major and found that LmRad9 and LmRad1 associate with chromatin in response to replication stress and form a complex in vivo with LmHus1. Similar to LmHus1, LmRad9 participates in telomere homeostasis and in the response to both replication stress and double strand breaks. However, LmRad9 and LmHus1‐deficient cells present markedly opposite phenotypes, which suggest their functional compartmentalization. We show that some of the cellular pool of LmRad9 forms an alternative complex and that some of LmHus1 exists as a monomer. We propose that the diverse assembly of the Leishmania 9‐1‐1 subunits mediates functional compartmentalization, which has a direct impact on the response to genotoxic stress.
Collapse
Affiliation(s)
- Jeziel D Damasceno
- Department of Cell and Molecular Biology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, 14049-900, Brazil
| | - Ricardo Obonaga
- Department of Cell and Molecular Biology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, 14049-900, Brazil
| | - Elaine V Santos
- Department of Cell and Molecular Biology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, 14049-900, Brazil
| | - Alan Scott
- The Wellcome Trust Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow; 120 University Place, Glasgow, G128TA, UK
| | - Richard McCulloch
- The Wellcome Trust Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow; 120 University Place, Glasgow, G128TA, UK
| | - Luiz R O Tosi
- Department of Cell and Molecular Biology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, 14049-900, Brazil.
| |
Collapse
|
17
|
Yanatori I, Richardson DR, Imada K, Kishi F. Iron Export through the Transporter Ferroportin 1 Is Modulated by the Iron Chaperone PCBP2. J Biol Chem 2016; 291:17303-18. [PMID: 27302059 DOI: 10.1074/jbc.m116.721936] [Citation(s) in RCA: 111] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Indexed: 12/15/2022] Open
Abstract
Ferroportin 1 (FPN1) is an iron export protein found in mammals. FPN1 is important for the export of iron across the basolateral membrane of absorptive enterocytes and across the plasma membrane of macrophages. The expression of FPN1 is regulated by hepcidin, which binds to FPN1 and then induces its degradation. Previously, we demonstrated that divalent metal transporter 1 (DMT1) interacts with the intracellular iron chaperone protein poly(rC)-binding protein 2 (PCBP2). Subsequently, PCBP2 receives iron from DMT1 and then disengages from the transporter. In this study, we investigated the function of PCBP2 in iron export. Mammalian genomes encode four PCBPs (i.e. PCBP1-4). Here, for the first time, we demonstrated using both yeast and mammalian cells that PCBP2, but not PCBP1, PCBP3, or PCBP4, binds with FPN1. Importantly, iron-loaded, but not iron-depleted, PCBP2 interacts with FPN1. The PCBP2-binding domain of FPN1 was identified in its C-terminal cytoplasmic region. The silencing of PCBP2 expression suppressed FPN1-dependent iron export from cells. These results suggest that FPN1 exports iron received from the iron chaperone PCBP2. Therefore, it was found that PCBP2 modulates cellular iron export, which is an important physiological process.
Collapse
Affiliation(s)
- Izumi Yanatori
- From the Department of Molecular Genetics, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama 701-0192, Japan and
| | - Des R Richardson
- the Molecular Pharmacology and Pathology Program, Department of Pathology, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Kiyoshi Imada
- From the Department of Molecular Genetics, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama 701-0192, Japan and
| | - Fumio Kishi
- From the Department of Molecular Genetics, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama 701-0192, Japan and
| |
Collapse
|
18
|
Reubens MC, Biller MD, Bedsole SE, Hopkins LT, Ables ET, Christensen TW. Mcm10 is required for oogenesis and early embryogenesis in Drosophila. Mech Dev 2015; 138 Pt 3:291-9. [PMID: 26369283 DOI: 10.1016/j.mod.2015.09.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Revised: 08/27/2015] [Accepted: 09/08/2015] [Indexed: 01/05/2023]
Abstract
Efficient replication of the genome and the establishment of endogenous chromatin states are processes that are essential to eukaryotic life. It is well documented that Mcm10 is intimately linked to both of these important biological processes; therefore, it is not surprising that Mcm10 is commonly misregulated in many human cancers. Most of the research regarding the biological roles of Mcm10 has been performed in single-cell or cell-free in-vitro systems. Though these systems are informative, they are unable to provide information on the cell-specific function of Mcm10 in the context of the tissue and organ systems that comprise multicellular eukaryotes. We therefore sought to identify the potential biological functions of Mcm10 in the context of a complex multicellular organism by continuing our analysis in Drosophila using three novel hypomorphic alleles. Observation of embryonic nuclear morphology and quantification of embryo hatch rates reveal that maternal loading of Mcm10 is required for embryonic nuclear stability, and suggest a role for Mcm10 post zygotic transition. Contrary to the essential nature of Mcm10 depicted in the literature, it does not appear to be required for adult viability in Drosophila if embryonic requirements are met. Although not required for adult somatic viability, analysis of fecundity and ovarian morphology in mutant females suggest that Mcm10 plays a role in maintenance of the female germline. Taken together, our results demonstrate critical roles for Mcm10 during early embryogenesis, and mark the first data linking Mcm10 to female specific reproduction in multicellular eukaryotes.
Collapse
Affiliation(s)
- Michael C Reubens
- Department of Biology, East Carolina University, Greenville, NC 27878, USA.
| | - Megan D Biller
- Department of Biology, East Carolina University, Greenville, NC 27878, USA.
| | - Sidney E Bedsole
- Department of Biology, East Carolina University, Greenville, NC 27878, USA.
| | - Lucas T Hopkins
- Department of Biology, East Carolina University, Greenville, NC 27878, USA.
| | - Elizabeth T Ables
- Department of Biology, East Carolina University, Greenville, NC 27878, USA.
| | - Tim W Christensen
- Department of Biology, East Carolina University, Greenville, NC 27878, USA.
| |
Collapse
|
19
|
Skoneczna A, Kaniak A, Skoneczny M. Genetic instability in budding and fission yeast-sources and mechanisms. FEMS Microbiol Rev 2015; 39:917-67. [PMID: 26109598 PMCID: PMC4608483 DOI: 10.1093/femsre/fuv028] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/26/2015] [Indexed: 12/17/2022] Open
Abstract
Cells are constantly confronted with endogenous and exogenous factors that affect their genomes. Eons of evolution have allowed the cellular mechanisms responsible for preserving the genome to adjust for achieving contradictory objectives: to maintain the genome unchanged and to acquire mutations that allow adaptation to environmental changes. One evolutionary mechanism that has been refined for survival is genetic variation. In this review, we describe the mechanisms responsible for two biological processes: genome maintenance and mutation tolerance involved in generations of genetic variations in mitotic cells of both Saccharomyces cerevisiae and Schizosaccharomyces pombe. These processes encompass mechanisms that ensure the fidelity of replication, DNA lesion sensing and DNA damage response pathways, as well as mechanisms that ensure precision in chromosome segregation during cell division. We discuss various factors that may influence genome stability, such as cellular ploidy, the phase of the cell cycle, transcriptional activity of a particular region of DNA, the proficiency of DNA quality control systems, the metabolic stage of the cell and its respiratory potential, and finally potential exposure to endogenous or environmental stress. The stability of budding and fission yeast genomes is influenced by two contradictory factors: (1) the need to be fully functional, which is ensured through the replication fidelity pathways of nuclear and mitochondrial genomes through sensing and repairing DNA damage, through precise chromosome segregation during cell division; and (2) the need to acquire changes for adaptation to environmental challenges.
Collapse
Affiliation(s)
- Adrianna Skoneczna
- Laboratory of Mutagenesis and DNA Repair, Institute of Biochemistry and Biophysics, Polish Academy of Science, 02-106 Warsaw, Poland
| | - Aneta Kaniak
- Laboratory of Mutagenesis and DNA Repair, Institute of Biochemistry and Biophysics, Polish Academy of Science, 02-106 Warsaw, Poland
| | - Marek Skoneczny
- Department of Genetics, Institute of Biochemistry and Biophysics, Polish Academy of Science, 02-106 Warsaw, Poland
| |
Collapse
|
20
|
Lim PX, Patel DR, Poisson KE, Basuita M, Tsai C, Lyndaker AM, Hwang BJ, Lu AL, Weiss RS. Genome Protection by the 9-1-1 Complex Subunit HUS1 Requires Clamp Formation, DNA Contacts, and ATR Signaling-independent Effector Functions. J Biol Chem 2015; 290:14826-40. [PMID: 25911100 DOI: 10.1074/jbc.m114.630640] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2014] [Indexed: 01/30/2023] Open
Abstract
The RAD9A-HUS1-RAD1 (9-1-1) complex is a heterotrimeric clamp that promotes checkpoint signaling and repair at DNA damage sites. In this study, we elucidated HUS1 functional residues that drive clamp assembly, DNA interactions, and downstream effector functions. First, we mapped a HUS1-RAD9A interface residue that was critical for 9-1-1 assembly and DNA loading. Next, we identified multiple positively charged residues in the inner ring of HUS1 that were crucial for genotoxin-induced 9-1-1 chromatin localization and ATR signaling. Finally, we found two hydrophobic pockets on the HUS1 outer surface that were important for cell survival after DNA damage. Interestingly, these pockets were not required for 9-1-1 chromatin localization or ATR-mediated CHK1 activation but were necessary for interactions between HUS1 and its binding partner MYH, suggesting that they serve as interaction domains for the recruitment and coordination of downstream effectors at damage sites. Together, these results indicate that, once properly loaded onto damaged DNA, the 9-1-1 complex executes multiple, separable functions that promote genome maintenance.
Collapse
Affiliation(s)
- Pei Xin Lim
- From the Department of Biomedical Sciences, Cornell University, Ithaca, New York 14853 and
| | - Darshil R Patel
- From the Department of Biomedical Sciences, Cornell University, Ithaca, New York 14853 and
| | - Kelsey E Poisson
- From the Department of Biomedical Sciences, Cornell University, Ithaca, New York 14853 and
| | - Manpreet Basuita
- From the Department of Biomedical Sciences, Cornell University, Ithaca, New York 14853 and
| | - Charlton Tsai
- From the Department of Biomedical Sciences, Cornell University, Ithaca, New York 14853 and
| | - Amy M Lyndaker
- From the Department of Biomedical Sciences, Cornell University, Ithaca, New York 14853 and
| | - Bor-Jang Hwang
- the Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - A-Lien Lu
- the Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Robert S Weiss
- From the Department of Biomedical Sciences, Cornell University, Ithaca, New York 14853 and
| |
Collapse
|