1
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Zhang Q, Lam WH, Zhai Y. Assembly and activation of replicative helicases at origin DNA for replication initiation. Curr Opin Struct Biol 2024; 88:102876. [PMID: 38986167 DOI: 10.1016/j.sbi.2024.102876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Revised: 06/01/2024] [Accepted: 06/14/2024] [Indexed: 07/12/2024]
Abstract
To initiate DNA replication, it is essential to properly assemble a pair of replicative helicases at each replication origin. While the general principle of this process applies universally from prokaryotes to eukaryotes, the specific mechanisms governing origin selection, helicase loading, and subsequent helicase activation vary significantly across different species. Recent advancements in cryo-electron microscopy (cryo-EM) have revolutionized our ability to visualize large protein or protein-DNA complexes involved in the initiation of DNA replication. Complemented by real-time single-molecule analysis, the available high-resolution cryo-EM structures have greatly enhanced our understanding of the dynamic regulation of this process at origin DNA. This review primarily focuses on the latest structural discoveries that shed light on the key molecular machineries responsible for driving replication initiation, with a particular emphasis on the assembly of pre-replication complex (pre-RC) in eukaryotes.
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Affiliation(s)
- Qiongdan Zhang
- School of Biological Sciences, The University of Hong Kong, Hong Kong
| | - Wai Hei Lam
- School of Biological Sciences, The University of Hong Kong, Hong Kong
| | - Yuanliang Zhai
- School of Biological Sciences, The University of Hong Kong, Hong Kong.
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2
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Li H, Stoltzfus AT, Michel SLJ. Mining proteomes for zinc finger persulfidation. RSC Chem Biol 2024; 5:572-585. [PMID: 38846077 PMCID: PMC11151867 DOI: 10.1039/d3cb00106g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 12/03/2023] [Indexed: 06/09/2024] Open
Abstract
Hydrogen sulfide (H2S) is an endogenous gasotransmitter that signals via persulfidation. There is evidence that the cysteine residues of certain zinc finger (ZF) proteins, a common type of cysteine rich protein, are modified to persulfides by H2S. To determine how frequently ZF persulfidation occurs in cells and identify the types of ZFs that are persulfidated, persulfide specific proteomics data were evaluated. 22 datasets from 16 studies were analyzed via a meta-analysis approach. Persulfidated ZFs were identified in a range of eukaryotic species, including Homo sapiens, Mus musculus, Rattus norvegicus, Arabidopsis thaliana, and Emiliania huxley (single-celled phytoplankton). The types of ZFs identified for each species encompassed all three common ZF ligand sets (4-cysteine, 3-cysteine-1-histidine, and 2-cysteine-2-hisitidine), indicating that persulfidation of ZFs is broad. Overlap analysis between different species identified several common ZFs. GO and KEGG analysis identified pathway enrichment for ubiquitin-dependent protein catabolic process and viral carcinogenesis. These collective findings support ZF persulfidation as a wide-ranging PTM that impacts all classes of ZFs.
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Affiliation(s)
- Haoju Li
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy Baltimore MD 21201 USA
| | - Andrew T Stoltzfus
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy Baltimore MD 21201 USA
| | - Sarah L J Michel
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy Baltimore MD 21201 USA
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3
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Liu Y, Zhangding Z, Liu X, Gan T, Ai C, Wu J, Liang H, Chen M, Guo Y, Lu R, Jiang Y, Ji X, Gao N, Kong D, Li Q, Hu J. Fork coupling directs DNA replication elongation and termination. Science 2024; 383:1215-1222. [PMID: 38484065 DOI: 10.1126/science.adj7606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 02/09/2024] [Indexed: 03/19/2024]
Abstract
DNA replication is initiated at multiple loci to ensure timely duplication of eukaryotic genomes. Sister replication forks progress bidirectionally, and replication terminates when two convergent forks encounter one another. To investigate the coordination of replication forks, we developed a replication-associated in situ HiC method to capture chromatin interactions involving nascent DNA. We identify more than 2000 fountain-like structures of chromatin contacts in human and mouse genomes, indicative of coupling of DNA replication forks. Replication fork interaction not only occurs between sister forks but also involves forks from two distinct origins to predetermine replication termination. Termination-associated chromatin fountains are sensitive to replication stress and lead to coupled forks-associated genomic deletions in cancers. These findings reveal the spatial organization of DNA replication forks within the chromatin context.
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Affiliation(s)
- Yang Liu
- The MOE Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Genome Editing Research Center, Peking University; Beijing 100871, China
- PKU-THU Center for Life Sciences, Peking University, Beijing 100871, China
| | - Zhengrong Zhangding
- The MOE Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Genome Editing Research Center, Peking University; Beijing 100871, China
| | - Xuhao Liu
- The MOE Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Genome Editing Research Center, Peking University; Beijing 100871, China
| | - Tingting Gan
- The MOE Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Genome Editing Research Center, Peking University; Beijing 100871, China
- PKU-THU Center for Life Sciences, Peking University, Beijing 100871, China
- Peking University ChengDu Academy for Advanced Interdisciplinary Biotechnologies, Chengdu, Sichuan 610213, China
| | - Chen Ai
- The MOE Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Genome Editing Research Center, Peking University; Beijing 100871, China
- PKU-THU Center for Life Sciences, Peking University, Beijing 100871, China
| | - Jinchun Wu
- The MOE Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Genome Editing Research Center, Peking University; Beijing 100871, China
- PKU-THU Center for Life Sciences, Peking University, Beijing 100871, China
| | - Haoxin Liang
- The MOE Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Genome Editing Research Center, Peking University; Beijing 100871, China
| | - Mohan Chen
- The MOE Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Genome Editing Research Center, Peking University; Beijing 100871, China
| | - Yuefeng Guo
- The MOE Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Genome Editing Research Center, Peking University; Beijing 100871, China
| | - Rusen Lu
- The MOE Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Genome Editing Research Center, Peking University; Beijing 100871, China
- PKU-THU Center for Life Sciences, Peking University, Beijing 100871, China
| | - Yongpeng Jiang
- The MOE Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Genome Editing Research Center, Peking University; Beijing 100871, China
- PKU-THU Center for Life Sciences, Peking University, Beijing 100871, China
| | - Xiong Ji
- The MOE Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Genome Editing Research Center, Peking University; Beijing 100871, China
- PKU-THU Center for Life Sciences, Peking University, Beijing 100871, China
| | - Ning Gao
- PKU-THU Center for Life Sciences, Peking University, Beijing 100871, China
- State Key Laboratory of Membrane Biology, School of Life Sciences, Peking University, Beijing 100871, China
| | - Daochun Kong
- PKU-THU Center for Life Sciences, Peking University, Beijing 100871, China
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China
| | - Qing Li
- PKU-THU Center for Life Sciences, Peking University, Beijing 100871, China
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China
| | - Jiazhi Hu
- The MOE Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Genome Editing Research Center, Peking University; Beijing 100871, China
- PKU-THU Center for Life Sciences, Peking University, Beijing 100871, China
- Peking University ChengDu Academy for Advanced Interdisciplinary Biotechnologies, Chengdu, Sichuan 610213, China
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4
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Li N, Gao Y, Zhang Y, Yu D, Lin J, Feng J, Li J, Xu Z, Zhang Y, Dang S, Zhou K, Liu Y, Li XD, Tye BK, Li Q, Gao N, Zhai Y. Parental histone transfer caught at the replication fork. Nature 2024; 627:890-897. [PMID: 38448592 DOI: 10.1038/s41586-024-07152-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 02/01/2024] [Indexed: 03/08/2024]
Abstract
In eukaryotes, DNA compacts into chromatin through nucleosomes1,2. Replication of the eukaryotic genome must be coupled to the transmission of the epigenome encoded in the chromatin3,4. Here we report cryo-electron microscopy structures of yeast (Saccharomyces cerevisiae) replisomes associated with the FACT (facilitates chromatin transactions) complex (comprising Spt16 and Pob3) and an evicted histone hexamer. In these structures, FACT is positioned at the front end of the replisome by engaging with the parental DNA duplex to capture the histones through the middle domain and the acidic carboxyl-terminal domain of Spt16. The H2A-H2B dimer chaperoned by the carboxyl-terminal domain of Spt16 is stably tethered to the H3-H4 tetramer, while the vacant H2A-H2B site is occupied by the histone-binding domain of Mcm2. The Mcm2 histone-binding domain wraps around the DNA-binding surface of one H3-H4 dimer and extends across the tetramerization interface of the H3-H4 tetramer to the binding site of Spt16 middle domain before becoming disordered. This arrangement leaves the remaining DNA-binding surface of the other H3-H4 dimer exposed to additional interactions for further processing. The Mcm2 histone-binding domain and its downstream linker region are nested on top of Tof1, relocating the parental histones to the replisome front for transfer to the newly synthesized lagging-strand DNA. Our findings offer crucial structural insights into the mechanism of replication-coupled histone recycling for maintaining epigenetic inheritance.
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Affiliation(s)
- Ningning Li
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing, China
| | - Yuan Gao
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Yujie Zhang
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
| | - Daqi Yu
- Division of Life Science, The Hong Kong University of Science & Technology, Hong Kong, China
- Department of Chemistry, The University of Hong Kong, Hong Kong, China
| | - Jianwei Lin
- Department of Chemistry, The University of Hong Kong, Hong Kong, China
| | - Jianxun Feng
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
| | - Jian Li
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Zhichun Xu
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Yingyi Zhang
- Biological Cryo-EM Center, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Shangyu Dang
- Division of Life Science, The Hong Kong University of Science & Technology, Hong Kong, China
| | - Keda Zhou
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - Yang Liu
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - Xiang David Li
- Department of Chemistry, The University of Hong Kong, Hong Kong, China
| | - Bik Kwoon Tye
- Department of Molecular Biology & Genetics, Cornell University, Ithaca, NY, USA.
| | - Qing Li
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China.
| | - Ning Gao
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing, China.
| | - Yuanliang Zhai
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China.
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5
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Boavida A, Napolitano LM, Santos D, Cortone G, Jegadesan NK, Onesti S, Branzei D, Pisani FM. FANCJ DNA helicase is recruited to the replisome by AND-1 to ensure genome stability. EMBO Rep 2024; 25:876-901. [PMID: 38177925 PMCID: PMC10897178 DOI: 10.1038/s44319-023-00044-y] [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: 10/09/2023] [Revised: 12/05/2023] [Accepted: 12/15/2023] [Indexed: 01/06/2024] Open
Abstract
FANCJ, a DNA helicase linked to Fanconi anemia and frequently mutated in cancers, counteracts replication stress by dismantling unconventional DNA secondary structures (such as G-quadruplexes) that occur at the DNA replication fork in certain sequence contexts. However, how FANCJ is recruited to the replisome is unknown. Here, we report that FANCJ directly binds to AND-1 (the vertebrate ortholog of budding yeast Ctf4), a homo-trimeric protein adaptor that connects the CDC45/MCM2-7/GINS replicative DNA helicase with DNA polymerase α and several other factors at DNA replication forks. The interaction between FANCJ and AND-1 requires the integrity of an evolutionarily conserved Ctf4-interacting protein (CIP) box located between the FANCJ helicase motifs IV and V. Disruption of the CIP box significantly reduces FANCJ association with the replisome, causing enhanced DNA damage, decreased replication fork recovery and fork asymmetry in cells unchallenged or treated with Pyridostatin, a G-quadruplex-binder, or Mitomycin C, a DNA inter-strand cross-linking agent. Cancer-relevant FANCJ CIP box variants display reduced AND-1-binding and enhanced DNA damage, a finding that suggests their potential role in cancer predisposition.
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Affiliation(s)
- Ana Boavida
- Istituto di Biochimica e Biologia Cellulare, Consiglio Nazionale delle Ricerche, Naples, Italy
- Università degli Studi della Campania "Luigi Vanvitelli", Caserta, Italy
| | | | - Diana Santos
- Istituto di Biochimica e Biologia Cellulare, Consiglio Nazionale delle Ricerche, Naples, Italy
- Università degli Studi della Campania "Luigi Vanvitelli", Caserta, Italy
| | - Giuseppe Cortone
- Istituto di Biochimica e Biologia Cellulare, Consiglio Nazionale delle Ricerche, Naples, Italy
| | | | - Silvia Onesti
- Structural Biology Laboratory, Elettra-Sincrotrone Trieste, Trieste, Italy
| | - Dana Branzei
- IFOM ETS-The AIRC Institute of Molecular Oncology, Milan, Italy
- Istituto di Genetica Molecolare, Consiglio Nazionale delle Ricerche, Pavia, Italy
| | - Francesca M Pisani
- Istituto di Biochimica e Biologia Cellulare, Consiglio Nazionale delle Ricerche, Naples, Italy.
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6
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Jin L, Huang J, Guo L, Zhang B, Li Q, Li H, Yu M, Xie P, Yu Q, Chen Z, Liu S, Xu Y, Xiao Y, Lu M, Ye Q. CYP1B1 promotes colorectal cancer liver metastasis by enhancing the growth of metastatic cancer cells via a fatty acids-dependent manner. J Gastrointest Oncol 2023; 14:2448-2465. [PMID: 38196537 PMCID: PMC10772677 DOI: 10.21037/jgo-23-895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Accepted: 12/14/2023] [Indexed: 01/11/2024] Open
Abstract
Background Liver metastasis (LM) accounts for most colorectal cancer (CRC)-related deaths. However, how metastatic CRC cells gain the ability to survive and grow in liver remains largely unknown. Methods First, we screened differentially expressed genes (DEGs) between LM and paired primary tumors (PTs) in Gene Expression Omnibus (GEO) database, and identified cytochrome P450 1B1 (CYP1B1) as the only common differential gene. Then, we verified messenger RNA (mRNA) and protein expression level in clinical specimens. After constructing stable up-regulated CYP1B1 versions of HCT116 and RKO CRC cells and stable down-regulated CYP1B1 versions of SW480 and HT29 CRC cells, cell proliferation assays, subcutaneous tumor formation, and mouse LM models were used to comprehend its function. Next, we used RNA-seq to uncover specific mechanisms of growth; cell cycle, polymerase chain reaction (PCR), western blot (WB) and GEO series (GSE) datasets were used to verify its mechanism. Last, gas chromatography tandem mass spectrometry (GC-MS/MS) was adopted to examine which fatty acids were changed. Results A significantly higher level of CYP1B1 was found in LM than in PT in paired clinical CRC LM samples (P<0.05). After CYP1B1 overexpression in HCT116 and RKO cells, cell proliferation abilities in vitro and in vivo were enhanced; LM of NOD.Cg-PrkdcscidIl2rgem1Smoc (NSG) mice were enhanced. And knockdown of CYP1B1 in SW480 and HT29 cells, cell proliferation abilities in vitro and in vivo were reduced; LM of NSG mice were declined (P<0.05). RNA-seq showed 59 common genes from upregulated genes of RKO overexpression group and downregulated genes of SW480 knockdown group were enriched in cell cycle and DNA replication. Further investigation revealed CYP1B1 regulated alternation of MCM5, PCNA, and FEN1 genes, and G1/S transition in CRC cells. GC-MS/MS revealed long chain fatty acids (LCFAs) made a difference in SW480 knockdown group (P<0.05). Through adding LCFAs into SW480 and HT29 knockdown groups, cell proliferation abilities in vitro and in vivo were enhanced, and expressions of MCM5, PCNA, FEN1 were upregulated (P<0.05). Conclusions CYP1B1 exerts a significant influence on LM of CRC by modulating tumor cell proliferation via "CYP1B1-LCFAs-G1/S transition". This finding suggests CYP1B1 could be a promising target for CRC LM.
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Affiliation(s)
- Lei Jin
- Department of Liver Surgery and Transplantation, Liver Cancer Institute, Zhongshan Hospital, Fudan University, Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Shanghai, China
| | - Ju Huang
- CAS Key Laboratory of Tissue Microenvironment and Tumor, Shanghai Institute of Nutrition and Health, Chinese Academy of Sciences, Shanghai, China
| | - Lei Guo
- Department of Liver Surgery and Transplantation, Liver Cancer Institute, Zhongshan Hospital, Fudan University, Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Shanghai, China
| | - Bo Zhang
- Department of Liver Surgery and Transplantation, Liver Cancer Institute, Zhongshan Hospital, Fudan University, Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Shanghai, China
| | - Qin Li
- CAS Key Laboratory of Tissue Microenvironment and Tumor, Shanghai Institute of Nutrition and Health, Chinese Academy of Sciences, Shanghai, China
| | - Hui Li
- Department of Liver Surgery and Transplantation, Liver Cancer Institute, Zhongshan Hospital, Fudan University, Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Shanghai, China
- Shanghai Medical College and Zhongshan Hospital Immunotherapy Technology Transfer Center, Shanghai, China
| | - Mincheng Yu
- Department of Liver Surgery and Transplantation, Liver Cancer Institute, Zhongshan Hospital, Fudan University, Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Shanghai, China
| | - Peiyi Xie
- Department of Liver Surgery and Transplantation, Liver Cancer Institute, Zhongshan Hospital, Fudan University, Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Shanghai, China
| | - Qiang Yu
- Department of Liver Surgery and Transplantation, Liver Cancer Institute, Zhongshan Hospital, Fudan University, Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Shanghai, China
| | - Zheng Chen
- Department of Liver Surgery and Transplantation, Liver Cancer Institute, Zhongshan Hospital, Fudan University, Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Shanghai, China
| | - Shuang Liu
- Neurosurgery Department of Zhongshan Hospital, Fudan University, Shanghai, China
| | - Yongfeng Xu
- Department of Liver Surgery and Transplantation, Liver Cancer Institute, Zhongshan Hospital, Fudan University, Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Shanghai, China
| | - Yongsheng Xiao
- Department of Liver Surgery and Transplantation, Liver Cancer Institute, Zhongshan Hospital, Fudan University, Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Shanghai, China
| | - Ming Lu
- CAS Key Laboratory of Tissue Microenvironment and Tumor, Shanghai Institute of Nutrition and Health, Chinese Academy of Sciences, Shanghai, China
| | - Qinghai Ye
- Department of Liver Surgery and Transplantation, Liver Cancer Institute, Zhongshan Hospital, Fudan University, Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Shanghai, China
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7
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Xia Y, Sonneville R, Jenkyn-Bedford M, Ji L, Alabert C, Hong Y, Yeeles JT, Labib KP. DNSN-1 recruits GINS for CMG helicase assembly during DNA replication initiation in Caenorhabditis elegans. Science 2023; 381:eadi4932. [PMID: 37590372 PMCID: PMC7615117 DOI: 10.1126/science.adi4932] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 08/07/2023] [Indexed: 08/19/2023]
Abstract
Assembly of the CMG (CDC-45-MCM-2-7-GINS) helicase is the key regulated step during eukaryotic DNA replication initiation. Until now, it was unclear whether metazoa require additional factors that are not present in yeast. In this work, we show that Caenorhabditis elegans DNSN-1, the ortholog of human DONSON, functions during helicase assembly in a complex with MUS-101/TOPBP1. DNSN-1 is required to recruit the GINS complex to chromatin, and a cryo-electron microscopy structure indicates that DNSN-1 positions GINS on the MCM-2-7 helicase motor (comprising the six MCM-2 to MCM-7 proteins), by direct binding of DNSN-1 to GINS and MCM-3, using interfaces that we show are important for initiation and essential for viability. These findings identify DNSN-1 as a missing link in our understanding of DNA replication initiation, suggesting that initiation defects underlie the human disease syndrome that results from DONSON mutations.
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Affiliation(s)
- Yisui Xia
- The MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, U.K
| | - Remi Sonneville
- The MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, U.K
| | | | - Liqin Ji
- Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, China
| | - Constance Alabert
- Division of Molecular, Cell & Developmental Biology, School of Life Sciences, University of Dundee, Dundee, U.K
| | - Ye Hong
- The MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, U.K
- Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, China
| | - Joseph T.P. Yeeles
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, U.K
| | - Karim P.M. Labib
- The MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, U.K
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8
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Xu Z, Feng J, Yu D, Huo Y, Ma X, Lam WH, Liu Z, Li XD, Ishibashi T, Dang S, Zhai Y. Synergism between CMG helicase and leading strand DNA polymerase at replication fork. Nat Commun 2023; 14:5849. [PMID: 37730685 PMCID: PMC10511561 DOI: 10.1038/s41467-023-41506-0] [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: 12/21/2021] [Accepted: 09/07/2023] [Indexed: 09/22/2023] Open
Abstract
The replisome that replicates the eukaryotic genome consists of at least three engines: the Cdc45-MCM-GINS (CMG) helicase that separates duplex DNA at the replication fork and two DNA polymerases, one on each strand, that replicate the unwound DNA. Here, we determined a series of cryo-electron microscopy structures of a yeast replisome comprising CMG, leading-strand polymerase Polε and three accessory factors on a forked DNA. In these structures, Polε engages or disengages with the motor domains of the CMG by occupying two alternative positions, which closely correlate with the rotational movement of the single-stranded DNA around the MCM pore. During this process, the polymerase remains stably coupled to the helicase using Psf1 as a hinge. This synergism is modulated by a concerted rearrangement of ATPase sites to drive DNA translocation. The Polε-MCM coupling is not only required for CMG formation to initiate DNA replication but also facilitates the leading-strand DNA synthesis mediated by Polε. Our study elucidates a mechanism intrinsic to the replisome that coordinates the activities of CMG and Polε to negotiate any roadblocks, DNA damage, and epigenetic marks encountered during translocation along replication forks.
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Affiliation(s)
- Zhichun Xu
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Jianrong Feng
- Division of Life Science, The Hong Kong University of Science & Technology, Hong Kong, China
| | - Daqi Yu
- Division of Life Science, The Hong Kong University of Science & Technology, Hong Kong, China
| | - Yunjing Huo
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Xiaohui Ma
- Division of Life Science, The Hong Kong University of Science & Technology, Hong Kong, China
| | - Wai Hei Lam
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Zheng Liu
- Department of Chemistry, The University of Hong Kong, Hong Kong, China
| | - Xiang David Li
- Department of Chemistry, The University of Hong Kong, Hong Kong, China
| | - Toyotaka Ishibashi
- Division of Life Science, The Hong Kong University of Science & Technology, Hong Kong, China
| | - Shangyu Dang
- Division of Life Science, The Hong Kong University of Science & Technology, Hong Kong, China.
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China.
- HKUST-Shenzhen Research Institute, 518057, Nanshan, Shenzhen, China.
| | - Yuanliang Zhai
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China.
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9
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Xiang S, Luo X, Welch D, Reed DR, Alexandrow MG. Identification of Selective ATP-Competitive CMG Helicase Inhibitors for Cancer Intervention that Disrupt CMG-Replisome Function. RESEARCH SQUARE 2023:rs.3.rs-3182731. [PMID: 37609279 PMCID: PMC10441460 DOI: 10.21203/rs.3.rs-3182731/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
The human CMG helicase (Cdc45-MCM-GINS) is a novel target for anti-cancer therapy due to tumor-specific weaknesses in CMG function induced by oncogenic changes and the need for CMG function during recovery from replicative stresses such as chemotherapy. Here, we developed an orthogonal biochemical screening approach and identified selective CMG inhibitors (CMGi) that inhibit ATPase and helicase activities in an ATP-competitive manner at low micromolar concentrations. Structure-activity information and in silico docking indicate that CMGi occupy ATP binding sites and channels within MCM subunits leading to the ATP clefts, which are likely used for ATP/ADP ingress or egress. CMGi inhibit cell growth and DNA replication using multiple molecular mechanisms. CMGi block helicase assembly steps that require ATP binding/hydrolysis by the MCM complex, specifically MCM ring assembly on DNA and GINS recruitment to DNA-loaded MCM hexamers. During S-phase, inhibition of MCM ATP binding/hydrolysis by CMGi causes a 'reverse allosteric' dissociation of Cdc45/GINS from the CMG that destabilizes the replisome and disrupts interactions with Ctf4, Mcm10, and DNA polymerase-α, -δ, -ε, resulting in DNA damage. These novel CMGi are selectively toxic toward tumor cells and define a new class of CMG helicase-targeted anti-cancer compounds with distinct mechanisms of action.
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Affiliation(s)
- Shengyan Xiang
- Cancer Biology and Evolution Program, Moffitt Cancer Center and Research Institute, Tampa, FL 33612
- Molecular Oncology Department, Moffitt Cancer Center and Research Institute, Tampa, FL 33612
| | - Xingju Luo
- Cancer Biology and Evolution Program, Moffitt Cancer Center and Research Institute, Tampa, FL 33612
- Molecular Oncology Department, Moffitt Cancer Center and Research Institute, Tampa, FL 33612
| | - Darcy Welch
- Cancer Biology and Evolution Program, Moffitt Cancer Center and Research Institute, Tampa, FL 33612
- Department of Individualized Cancer Management, Moffitt Cancer Center and Research Institute, Tampa, FL 33612
| | - Damon R. Reed
- Cancer Biology and Evolution Program, Moffitt Cancer Center and Research Institute, Tampa, FL 33612
- Department of Individualized Cancer Management, Moffitt Cancer Center and Research Institute, Tampa, FL 33612
| | - Mark G. Alexandrow
- Cancer Biology and Evolution Program, Moffitt Cancer Center and Research Institute, Tampa, FL 33612
- Molecular Oncology Department, Moffitt Cancer Center and Research Institute, Tampa, FL 33612
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10
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Boldinova EO, Makarova AV. Regulation of Human DNA Primase-Polymerase PrimPol. BIOCHEMISTRY. BIOKHIMIIA 2023; 88:1139-1155. [PMID: 37758313 DOI: 10.1134/s0006297923080084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 06/27/2023] [Accepted: 06/28/2023] [Indexed: 10/03/2023]
Abstract
Transmission of genetic information depends on successful completion of DNA replication. Genomic DNA is subjected to damage on a daily basis. DNA lesions create obstacles for DNA polymerases and can lead to the replication blockage, formation of DNA breaks, cell cycle arrest, and apoptosis. Cells have evolutionary adapted to DNA damage by developing mechanisms allowing elimination of lesions prior to DNA replication (DNA repair) and helping to bypass lesions during DNA synthesis (DNA damage tolerance). The second group of mechanisms includes the restart of DNA synthesis at the sites of DNA damage by DNA primase-polymerase PrimPol. Human PrimPol was described in 2013. The properties and functions of this enzyme have been extensively studied in recent years, but very little is known about the regulation of PrimPol and association between the enzyme dysfunction and diseases. In this review, we described the mechanisms of human PrimPol regulation in the context of DNA replication, discussed in detail interactions of PrimPol with other proteins, and proposed possible pathways for the regulation of human PrimPol activity. The article also addresses the association of PrimPol dysfunction with human diseases.
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Affiliation(s)
- Elizaveta O Boldinova
- Kurchatov Institute National Research Centre, Moscow, 123182, Russia.
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334, Russia
| | - Alena V Makarova
- Kurchatov Institute National Research Centre, Moscow, 123182, Russia
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334, Russia
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11
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Pellegrini L. The CMG DNA helicase and the core replisome. Curr Opin Struct Biol 2023; 81:102612. [PMID: 37244171 DOI: 10.1016/j.sbi.2023.102612] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Revised: 04/19/2023] [Accepted: 04/25/2023] [Indexed: 05/29/2023]
Abstract
Eukaryotic DNA replication is performed by the replisome, a large and dynamic multi-protein machine endowed with the required enzymatic components for the synthesis of new DNA. Recent cryo-electron microscopy (cryoEM) analyses have revealed the conserved architecture of the core eukaryotic replisome, comprising the CMG (Cdc45-MCM-GINS) DNA helicase, the leading-strand DNA polymerase epsilon, the Timeless-Tipin heterodimer, the hub protein AND-1 and the checkpoint protein Claspin. These results bid well for arriving soon at an integrated understanding of the structural basis of semi-discontinuous DNA replication. They further set the scene for the characterisation of the mechanisms that interface DNA synthesis with concurrent processes such as DNA repair, propagation of chromatin structure and establishment of sister chromatid cohesion.
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12
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Harada Y, Mizote Y, Suzuki T, Hirayama A, Ikeda S, Nishida M, Hiratsuka T, Ueda A, Imagawa Y, Maeda K, Ohkawa Y, Murai J, Freeze HH, Miyoshi E, Higashiyama S, Udono H, Dohmae N, Tahara H, Taniguchi N. Metabolic clogging of mannose triggers dNTP loss and genomic instability in human cancer cells. eLife 2023; 12:e83870. [PMID: 37461317 DOI: 10.7554/elife.83870] [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: 09/30/2022] [Accepted: 06/12/2023] [Indexed: 07/20/2023] Open
Abstract
Mannose has anticancer activity that inhibits cell proliferation and enhances the efficacy of chemotherapy. How mannose exerts its anticancer activity, however, remains poorly understood. Here, using genetically engineered human cancer cells that permit the precise control of mannose metabolic flux, we demonstrate that the large influx of mannose exceeding its metabolic capacity induced metabolic remodeling, leading to the generation of slow-cycling cells with limited deoxyribonucleoside triphosphates (dNTPs). This metabolic remodeling impaired dormant origin firing required to rescue stalled forks by cisplatin, thus exacerbating replication stress. Importantly, pharmacological inhibition of de novo dNTP biosynthesis was sufficient to retard cell cycle progression, sensitize cells to cisplatin, and inhibit dormant origin firing, suggesting dNTP loss-induced genomic instability as a central mechanism for the anticancer activity of mannose.
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Affiliation(s)
- Yoichiro Harada
- Department of Glyco-Oncology and Medical Biochemistry, Research Institute, Osaka International Cancer Institute, Osaka, Japan
| | - Yu Mizote
- Department of Cancer Drug Discovery and Development, Research Institute, Osaka International Cancer Institute, Osaka, Japan
| | - Takehiro Suzuki
- Biomolecular Characterization Unit, RIKEN Center for Sustainable Resource Science, Saitama, Japan
| | - Akiyoshi Hirayama
- Institute for Advanced Biosciences, Keio University, Yamagata, Japan
- Systems Biology Program, Graduate School of Media and Governance, Keio University, Kanagawa, Japan
| | - Satsuki Ikeda
- Institute for Advanced Biosciences, Keio University, Yamagata, Japan
| | - Mikako Nishida
- Department of Immunology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Toru Hiratsuka
- Department of Oncogenesis and Growth Regulation, Research Institute, Osaka International Cancer Institute, Osaka, Japan
| | - Ayaka Ueda
- Department of Molecular Biochemistry and Clinical Investigation, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Yusuke Imagawa
- Department of Oncogenesis and Growth Regulation, Research Institute, Osaka International Cancer Institute, Osaka, Japan
| | - Kento Maeda
- Department of Glyco-Oncology and Medical Biochemistry, Research Institute, Osaka International Cancer Institute, Osaka, Japan
| | - Yuki Ohkawa
- Department of Glyco-Oncology and Medical Biochemistry, Research Institute, Osaka International Cancer Institute, Osaka, Japan
| | - Junko Murai
- Institute for Advanced Biosciences, Keio University, Yamagata, Japan
- Division of Cell Growth and Tumor Regulation, Proteo-Science Center, Ehime University, Ehime, Japan
- Department of Biochemistry and Molecular Genetics, Graduate School of Medicine, Ehime University, Ehime, Japan
| | - Hudson H Freeze
- Human Genetics Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, United States
| | - Eiji Miyoshi
- Department of Molecular Biochemistry and Clinical Investigation, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Shigeki Higashiyama
- Department of Oncogenesis and Growth Regulation, Research Institute, Osaka International Cancer Institute, Osaka, Japan
- Division of Cell Growth and Tumor Regulation, Proteo-Science Center, Ehime University, Ehime, Japan
- Department of Biochemistry and Molecular Genetics, Graduate School of Medicine, Ehime University, Ehime, Japan
| | - Heiichiro Udono
- Department of Immunology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Naoshi Dohmae
- Biomolecular Characterization Unit, RIKEN Center for Sustainable Resource Science, Saitama, Japan
| | - Hideaki Tahara
- Department of Cancer Drug Discovery and Development, Research Institute, Osaka International Cancer Institute, Osaka, Japan
- Project Division of Cancer Biomolecular Therapy, Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - Naoyuki Taniguchi
- Department of Glyco-Oncology and Medical Biochemistry, Research Institute, Osaka International Cancer Institute, Osaka, Japan
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13
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Vilas JL, Tagare HD. New measures of anisotropy of cryo-EM maps. Nat Methods 2023:10.1038/s41592-023-01874-3. [PMID: 37248387 DOI: 10.1038/s41592-023-01874-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 04/05/2023] [Indexed: 05/31/2023]
Abstract
We propose two new measures of resolution anisotropy for cryogenic electron microscopy maps: Fourier shell occupancy (FSO), and the Bingham test (BT). FSO varies from 1 to 0, with 1 representing perfect isotropy, and lower values indicating increasing anisotropy. The threshold FSO = 0.5 occurs at Fourier shell correlation resolution. BT is a hypothesis test that complements the FSO to ensure the existence of anisotropy. FSO and BT allow visualization of resolution anisotropy. We illustrate their use with different experimental cryogenic electron microscopy maps.
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Affiliation(s)
- Jose-Luis Vilas
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, USA.
| | - Hemant D Tagare
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, USA.
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA.
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14
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Bartolec TK, Vázquez-Campos X, Norman A, Luong C, Johnson M, Payne RJ, Wilkins MR, Mackay JP, Low JKK. Cross-linking mass spectrometry discovers, evaluates, and corroborates structures and protein-protein interactions in the human cell. Proc Natl Acad Sci U S A 2023; 120:e2219418120. [PMID: 37071682 PMCID: PMC10151615 DOI: 10.1073/pnas.2219418120] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 03/16/2023] [Indexed: 04/19/2023] Open
Abstract
Significant recent advances in structural biology, particularly in the field of cryoelectron microscopy, have dramatically expanded our ability to create structural models of proteins and protein complexes. However, many proteins remain refractory to these approaches because of their low abundance, low stability, or-in the case of complexes-simply not having yet been analyzed. Here, we demonstrate the power of using cross-linking mass spectrometry (XL-MS) for the high-throughput experimental assessment of the structures of proteins and protein complexes. This included those produced by high-resolution but in vitro experimental data, as well as in silico predictions based on amino acid sequence alone. We present the largest XL-MS dataset to date, describing 28,910 unique residue pairs captured across 4,084 unique human proteins and 2,110 unique protein-protein interactions. We show that models of proteins and their complexes predicted by AlphaFold2, and inspired and corroborated by the XL-MS data, offer opportunities to deeply mine the structural proteome and interactome and reveal mechanisms underlying protein structure and function.
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Affiliation(s)
- Tara K. Bartolec
- Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Randwick, NSW2052, Australia
| | - Xabier Vázquez-Campos
- Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Randwick, NSW2052, Australia
| | - Alexander Norman
- School of Chemistry, University of Sydney, Sydney, NSW2006, Australia
| | - Clement Luong
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW2006, Australia
| | - Marcus Johnson
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW2006, Australia
| | - Richard J. Payne
- School of Chemistry, University of Sydney, Sydney, NSW2006, Australia
- Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Sydney, Sydney, NSW2006, Australia
| | - Marc R. Wilkins
- Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Randwick, NSW2052, Australia
| | - Joel P. Mackay
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW2006, Australia
| | - Jason K. K. Low
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW2006, Australia
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15
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A Data-Mining Approach to Identify NF-kB-Responsive microRNAs in Tissues Involved in Inflammatory Processes: Potential Relevance in Age-Related Diseases. Int J Mol Sci 2023; 24:ijms24065123. [PMID: 36982191 PMCID: PMC10049099 DOI: 10.3390/ijms24065123] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 03/02/2023] [Accepted: 03/04/2023] [Indexed: 03/11/2023] Open
Abstract
The nuclear factor NF-kB is the master transcription factor in the inflammatory process by modulating the expression of pro-inflammatory genes. However, an additional level of complexity is the ability to promote the transcriptional activation of post-transcriptional modulators of gene expression as non-coding RNA (i.e., miRNAs). While NF-kB’s role in inflammation-associated gene expression has been extensively investigated, the interplay between NF-kB and genes coding for miRNAs still deserves investigation. To identify miRNAs with potential NF-kB binding sites in their transcription start site, we predicted miRNA promoters by an in silico analysis using the PROmiRNA software, which allowed us to score the genomic region’s propensity to be miRNA cis-regulatory elements. A list of 722 human miRNAs was generated, of which 399 were expressed in at least one tissue involved in the inflammatory processes. The selection of “high-confidence” hairpins in miRbase identified 68 mature miRNAs, most of them previously identified as inflammamiRs. The identification of targeted pathways/diseases highlighted their involvement in the most common age-related diseases. Overall, our results reinforce the hypothesis that persistent activation of NF-kB could unbalance the transcription of specific inflammamiRNAs. The identification of such miRNAs could be of diagnostic/prognostic/therapeutic relevance for the most common inflammatory-related and age-related diseases.
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16
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Yang J, Sun Y, Wang Y, Hao W, Cheng K. Structural and DNA end resection study of the bacterial NurA-HerA complex. BMC Biol 2023; 21:42. [PMID: 36829173 PMCID: PMC9960219 DOI: 10.1186/s12915-023-01542-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 02/10/2023] [Indexed: 02/26/2023] Open
Abstract
BACKGROUND The nuclease NurA and the ATPase/translocase HerA play a vital role in repair of double-strand breaks (DSB) during the homologous recombination in archaea. A NurA-HerA complex is known to mediate DSB DNA end resection, leading to formation of a free 3' end used to search for the homologous sequence. Despite the structures of individual archaeal types of NurA and HerA having been reported, there is limited information regarding the molecular mechanisms underlying this process. Some bacteria also possess homologs of NurA and HerA; however, the bacterial type of this complex, as well as the detailed mechanisms underlying the joining of NurA-HerA in DSB DNA end resection, remains unclear. RESULTS We report for the first time the crystal structures of Deinococcus radiodurans HerA (drHerA) in the nucleotide-free and ADP-binding modes. A D. radiodurans NurA-HerA complex structure was constructed according to a low-resolution cryo-electron microscopy map. We performed site-directed mutagenesis to map the drNurA-HerA interaction sites, suggesting that their interaction is mainly mediated by ionic links, in contrast to previously characterized archaeal NurA-HerA interactions. The key residues responsible for the DNA translocation activity, DNA unwinding activity, and catalytic activities of the drNurA-HerA complex were identified. A HerA/FtsK-specific translocation-related motif (TR motif) that guarantees the processivity of double-stranded DNA (dsDNA) translocation was identified. Moreover, a mechanism for the translocation-regulated resection of the 5' tail of broken dsDNA and the corresponding generation of a recombinogenic 3' single-stranded DNA tail by the drNurA-HerA complex was elucidated. CONCLUSIONS Our work provides new insights into the mechanism underlying bacterial NurA-HerA-mediated DSB DNA end resection, and the way this complex digests the 5' tail of a DNA duplex and provides long 3' free end for strand invasion in the bacterial homologous recombination process.
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Affiliation(s)
- Jieyu Yang
- grid.410595.c0000 0001 2230 9154Key Laboratory of Aging and Cancer Biology of Zhejiang Province, Department of Immunology and Pathogen Biology, School of Basic Medical Sciences, Hangzhou Normal University, Hangzhou, 311121 China
| | - Yiyang Sun
- grid.410595.c0000 0001 2230 9154Key Laboratory of Aging and Cancer Biology of Zhejiang Province, Department of Immunology and Pathogen Biology, School of Basic Medical Sciences, Hangzhou Normal University, Hangzhou, 311121 China
| | - Ying Wang
- grid.410595.c0000 0001 2230 9154Key Laboratory of Aging and Cancer Biology of Zhejiang Province, Department of Immunology and Pathogen Biology, School of Basic Medical Sciences, Hangzhou Normal University, Hangzhou, 311121 China
| | - Wanshan Hao
- grid.410595.c0000 0001 2230 9154Key Laboratory of Aging and Cancer Biology of Zhejiang Province, Department of Immunology and Pathogen Biology, School of Basic Medical Sciences, Hangzhou Normal University, Hangzhou, 311121 China
| | - Kaiying Cheng
- Key Laboratory of Aging and Cancer Biology of Zhejiang Province, Department of Immunology and Pathogen Biology, School of Basic Medical Sciences, Hangzhou Normal University, Hangzhou, 311121, China. .,State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, 310003, China.
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17
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The CMG helicase and cancer: a tumor "engine" and weakness with missing mutations. Oncogene 2023; 42:473-490. [PMID: 36522488 PMCID: PMC9948756 DOI: 10.1038/s41388-022-02572-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 12/01/2022] [Accepted: 12/07/2022] [Indexed: 12/23/2022]
Abstract
The replicative Cdc45-MCM-GINS (CMG) helicase is a large protein complex that functions in the DNA melting and unwinding steps as a component of replisomes during DNA replication in mammalian cells. Although the CMG performs this important role in cell growth, the CMG is not a simple bystander in cell cycle events. Components of the CMG, specifically the MCM precursors, are also involved in maintaining genomic stability by regulating DNA replication fork speeds, facilitating recovery from replicative stresses, and preventing consequential DNA damage. Given these important functions, MCM/CMG complexes are highly regulated by growth factors such as TGF-ß1 and by signaling factors such as Myc, Cyclin E, and the retinoblastoma protein. Mismanagement of MCM/CMG complexes when these signaling mediators are deregulated, and in the absence of the tumor suppressor protein p53, leads to increased genomic instability and is a contributor to tumorigenic transformation and tumor heterogeneity. The goal of this review is to provide insight into the mechanisms and dynamics by which the CMG is regulated during its assembly and activation in mammalian genomes, and how errors in CMG regulation due to oncogenic changes promote tumorigenesis. Finally, and most importantly, we highlight the emerging understanding of the CMG helicase as an exploitable vulnerability and novel target for therapeutic intervention in cancer.
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18
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The human pre-replication complex is an open complex. Cell 2023; 186:98-111.e21. [PMID: 36608662 DOI: 10.1016/j.cell.2022.12.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Revised: 10/13/2022] [Accepted: 12/05/2022] [Indexed: 01/07/2023]
Abstract
In eukaryotes, DNA replication initiation requires assembly and activation of the minichromosome maintenance (MCM) 2-7 double hexamer (DH) to melt origin DNA strands. However, the mechanism for this initial melting is unknown. Here, we report a 2.59-Å cryo-electron microscopy structure of the human MCM-DH (hMCM-DH), also known as the pre-replication complex. In this structure, the hMCM-DH with a constricted central channel untwists and stretches the DNA strands such that almost a half turn of the bound duplex DNA is distorted with 1 base pair completely separated, generating an initial open structure (IOS) at the hexamer junction. Disturbing the IOS inhibits DH formation and replication initiation. Mapping of hMCM-DH footprints indicates that IOSs are distributed across the genome in large clusters aligning well with initiation zones designed for stochastic origin firing. This work unravels an intrinsic mechanism that couples DH formation with initial DNA melting to license replication initiation in human cells.
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19
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Samdani MN, Reza R, Morshed N, Asaduzzaman M, Islam ABMMK. Ligand-based modelling for screening natural compounds targeting Minichromosome Maintenance Complex Component-7 for potential anticancer effects. INFORMATICS IN MEDICINE UNLOCKED 2023. [DOI: 10.1016/j.imu.2022.101152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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20
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SV40 T-antigen uses a DNA shearing mechanism to initiate origin unwinding. Proc Natl Acad Sci U S A 2022; 119:e2216240119. [PMID: 36442086 PMCID: PMC9894130 DOI: 10.1073/pnas.2216240119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Duplication of DNA genomes requires unwinding of the double-strand (ds) DNA so that each single strand (ss) can be copied by a DNA polymerase. The genomes of eukaryotic cells are unwound by two ring-shaped hexameric helicases that initially encircle dsDNA but transition to ssDNA for function as replicative helicases. How the duplex is initially unwound, and the role of the two helicases in this process, is poorly understood. We recently described an initiation mechanism for eukaryotes in which the two helicases are directed inward toward one another and shear the duplex open by pulling on opposite strands of the duplex while encircling dsDNA [L. D. Langston, M. E. O'Donnell, eLife 8, e46515 (2019)]. Two head-to-head T-Antigen helicases are long known to be loaded at the SV40 origin. We show here that T-Antigen tracks head (N-tier) first on ssDNA, opposite the direction proposed for decades. We also find that SV40 T-Antigen tracks directionally while encircling dsDNA and mainly tracks on one strand of the duplex in the same orientation as during ssDNA translocation. Further, two inward directed T-Antigen helicases on dsDNA are able to melt a 150-bp duplex. These findings explain the "rabbit ear" DNA loops observed at the SV40 origin by electron microscopy and reconfigure how the DNA loops emerge from the double hexamer relative to earlier models. Thus, the mechanism of DNA shearing by two opposing helicases is conserved in a eukaryotic viral helicase and may be widely used to initiate origin unwinding of dsDNA genomes.
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21
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Two Distinct Modes of DNA Binding by an MCM Helicase Enable DNA Translocation. Int J Mol Sci 2022; 23:ijms232314678. [PMID: 36499022 PMCID: PMC9735655 DOI: 10.3390/ijms232314678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 11/11/2022] [Accepted: 11/16/2022] [Indexed: 11/26/2022] Open
Abstract
A six-subunit ATPase ring forms the central hub of the replication forks in all domains of life. This ring performs a helicase function to separate the two complementary DNA strands to be replicated and drives the replication machinery along the DNA. Disruption of this helicase/ATPase ring is associated with genetic instability and diseases such as cancer. The helicase/ATPase rings of eukaryotes and archaea consist of six minichromosome maintenance (MCM) proteins. Prior structural studies have shown that MCM rings bind one encircled strand of DNA in a spiral staircase, suggesting that the ring pulls this strand of DNA through its central pore in a hand-over-hand mechanism where the subunit at the bottom of the staircase dissociates from DNA and re-binds DNA one step above the staircase. With high-resolution cryo-EM, we show that the MCM ring of the archaeal organism Saccharolobus solfataricus binds an encircled DNA strand in two different modes with different numbers of subunits engaged to DNA, illustrating a plausible mechanism for the alternating steps of DNA dissociation and re-association that occur during DNA translocation.
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22
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Mukherjee S, Das S, Sriram N, Chakraborty S, Sah MK. In silico investigation of the role of vitamins in cancer therapy through inhibition of MCM7 oncoprotein. RSC Adv 2022; 12:31004-31015. [PMID: 36349041 PMCID: PMC9619486 DOI: 10.1039/d2ra03703c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 08/18/2022] [Indexed: 11/30/2022] Open
Abstract
An overabundance of MCM7 protein, a component of the minichromosome maintenance complex that normally initiates DNA replication, has been reported to cause different types of cancers with aggressive malignancy. Inhibition of MCM7 may lead to a significant reduction in cancer-associated cell proliferation. Despite such significance of MCM7 in cancer, the protein structure is yet to be resolved experimentally. This significantly halts the structure-guided ligand designing for cancer therapy targeting the MCM7. The present study aims to resolve the tertiary structure of MCM7 and repurpose the FDA-approved clinically used drugs for cancer therapy by targeting MCM7 protein. The secondary and 3D structures of MCM7 were generated using multiple bioinformatics tools, including the Self-Optimized Prediction Method with Alignment (SOPMA), SWISS-MODEL, and I-TASSER. The reliability of the modeled structure was assessed using PROCHECK. Initially, a structure-guided virtual screening was performed on the approved drug library to identify potential hits against MCM7. The detailed molecular mechanism of receptor interactions of the identified hits was evaluated using extensive molecular dynamics simulation. The results from this study reveal an intriguing discovery of the potential of ergocalciferol (vitamin D2), cholecalciferol (vitamin D3), ergosterol (precursor of vitamin D2) and menaquinone (vitamin K2) as oncoprotein inhibitors for cancer therapy via inhibition of MCM7.
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Affiliation(s)
- Sunny Mukherjee
- Department of Biotechnology, Dr B. R. Ambedkar National Institute of TechnologyJalandharPunjab-144011India
| | - Sucharita Das
- Department of Microbiology, University of Calcutta35 BallygungeKolkata700 019India
| | - Navneeth Sriram
- Department of Biotechnology, Dr B. R. Ambedkar National Institute of TechnologyJalandharPunjab-144011India,Department of Biosciences and Bioengineering, Indian Institute of TechnologyGuwahatiAssam-781039India
| | - Sandipan Chakraborty
- Center for Innovation in Molecular and Pharmaceutical Sciences (CIMPS), Dr Reddy's Institute of Life Sciences, University of Hyderabad CampusGachibowliHyderabad 500046India
| | - Mahesh Kumar Sah
- Department of Biotechnology, Dr B. R. Ambedkar National Institute of TechnologyJalandharPunjab-144011India
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23
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Zhang X, Chen H, Lin H, Wen R, Yang F. High-Throughput Screening and Molecular Dynamics Simulation of Natural Products for the Identification of Anticancer Agents against MCM7 Protein. Appl Bionics Biomech 2022; 2022:8308192. [PMID: 36157125 PMCID: PMC9499818 DOI: 10.1155/2022/8308192] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 08/16/2022] [Accepted: 08/20/2022] [Indexed: 11/18/2022] Open
Abstract
Minichromosome maintenance complex component 7 (MCM7) belongs to the minichromosome maintenance family that is necessary for the initiation of eukaryotic DNA replication. Overexpression of the MCM7 protein is linked to cellular proliferation and is accountable for critical malignancy in many cancers. Mechanistically, the suppression of MCM7 greatly lowers the cellular proliferation associated with cancer. Advances in immunotherapy have revolutionized treatments for many types of cancer. To date, no effective small molecular candidate has been found that can stop the advancement of cancer produced by the MCM7 protein. Here, we present the findings of methods that used a combination of structure-assisted drug design, high-throughput virtual screening, and simulations studies to swiftly generate lead compounds against MCM7 protein. In the current study, we designed efficient compounds that may combat all emerging cancer targeting the common MCM7 protein. For this objective, a molecular docking and molecular dynamics (MD) simulation-based virtual screening of 29,000 NPASS library was carried out. As a consequence of using specific pharmacological, physiological, and ADMET criteria, four new prevailing compounds, NPA000018, NPA000111, NPA00305, and NPA014826, were successfully selected. The MD simulations were also used for a time period of 50 ns to evaluate for stability and dynamics behavior of the compounds. Eventually, compounds NPA000111 and NPA014826 were found to be highly potent against MCM7 protein. According to our results, the selected compounds may be effective in treating certain cancer subtypes, for which additional follow-up experimental validation is recommended.
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Affiliation(s)
- Xin Zhang
- Breast Surgery Department, Affiliated Fuzhou First Hospital of Fujian Medical University, Fuzhou 350009, China
| | - Hui Chen
- Breast Surgery Department, Affiliated Fuzhou First Hospital of Fujian Medical University, Fuzhou 350009, China
| | - Hui Lin
- Breast Surgery Department, Affiliated Fuzhou First Hospital of Fujian Medical University, Fuzhou 350009, China
| | - Ronglan Wen
- Breast Surgery Department, Affiliated Fuzhou First Hospital of Fujian Medical University, Fuzhou 350009, China
| | - Fan Yang
- Breast Surgery Department, Affiliated Fuzhou First Hospital of Fujian Medical University, Fuzhou 350009, China
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Cryo-EM structure of human hexameric MCM2-7 complex. iScience 2022; 25:104976. [PMID: 36117988 PMCID: PMC9475327 DOI: 10.1016/j.isci.2022.104976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 06/28/2022] [Accepted: 08/15/2022] [Indexed: 11/21/2022] Open
Abstract
The central step in the initiation of eukaryotic DNA replication is the loading of the minichromosome maintenance 2–7 (MCM2-7) complex, the core of the replicative DNA helicase, onto chromatin at replication origin. Here, we reported the cryo-EM structure of endogenous human single hexameric MCM2-7 complex with a resolution at 4.4 Å, typically an open-ring hexamer with a gap between Mcm2 and Mcm5. Strikingly, further analysis revealed that human MCM2-7 can self-associate to form a loose double hexamer which potentially implies a novel mechanism underlying the MCM2-7 loading in eukaryote. The high-resolution cryo-EM structure of human MCM2-7 is critical for understanding the molecular mechanisms governing human DNA replication, especially the MCM2-7 chromatin loading and pre-replicative complex assembly. A Twin-Strep-Tag II tag was fused to Mcm4 by using CRISPR-Cas9 technique The endogenous human MCM2-7 complex was successfully purified The high-resolution cryo-EM structure of human hexameric MCM2-7 complex The human single MCM2-7 hexamer can self-associate to form a double hexamer
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Extended DNA binding interfaces beyond the canonical SAP domain contribute to the function of replication stress regulator SDE2 at DNA replication forks. J Biol Chem 2022; 298:102268. [PMID: 35850305 PMCID: PMC9399289 DOI: 10.1016/j.jbc.2022.102268] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 07/05/2022] [Accepted: 07/07/2022] [Indexed: 11/25/2022] Open
Abstract
Elevated DNA replication stress causes instability of the DNA replication fork and increased DNA mutations, which underlies tumorigenesis. The DNA replication stress regulator silencing-defective 2 (SDE2) is known to bind to TIMELESS (TIM), a protein of the fork protection complex, and enhances its stability, thereby supporting replisome activity at DNA replication forks. However, the DNA-binding activity of SDE2 is not well defined. Here, we structurally and functionally characterize a new conserved DNA-binding motif related to the SAP (SAF-A/B, Acinus, PIAS) domain in human SDE2 and establish its preference for ssDNA. Our NMR solution structure of the SDE2SAP domain reveals a helix-extended loop-helix core with the helices aligned parallel to each other, consistent with known canonical SAP folds. Notably, we have shown that the DNA interaction of this SAP domain extends beyond the core SAP domain and is augmented by two lysine residues in the C-terminal tail, which is uniquely positioned adjacent to the SAP motif and conserved in the pre-mRNA splicing factor SF3A3. Furthermore, we found that mutation in the SAP domain and extended C terminus not only disrupts ssDNA binding but also impairs TIM localization at replication forks, thus inhibiting efficient fork progression. Taken together, our results establish SDE2SAP as an essential element for SDE2 to exert its role in preserving replication fork integrity via fork protection complex regulation and highlight the structural diversity of the DNA–protein interactions achieved by a specialized DNA-binding motif.
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Fitoussi N, de Almeida Engler J, Sichov N, Bucki P, Sela N, Harel A, Belausuv E, Kumar A, Brown Miyara S. The Minichromosome Maintenance Complex Component 2 (MjMCM2) of Meloidogyne javanica is a potential effector regulating the cell cycle in nematode-induced galls. Sci Rep 2022; 12:9196. [PMID: 35654810 PMCID: PMC9163083 DOI: 10.1038/s41598-022-13020-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 05/12/2022] [Indexed: 11/09/2022] Open
Abstract
Root-knot nematodes Meloidogyne spp. induce enlarged multinucleate feeding cells—galls—in host plant roots. Although core cell-cycle components in galls follow a conserved track, they can also be usurped and manipulated by nematodes. We identified a candidate effector in Meloidogyne javanica that is directly involved in cell-cycle manipulation—Minichromosome Maintenance Complex Component 2 (MCM2), part of MCM complex licensing factor involved in DNA replication. MjMCM2, which is induced by plant oxilipin 9-HOT, was expressed in nematode esophageal glands, upregulated during parasitic stages, and was localized to plant cell nucleus and plasma membrane. Infected tomato hairy roots overexpressing MjMCM2 showed significantly more galls and egg-mass-producing females than wild-type roots, and feeding cells showed more nuclei. Phylogenetic analysis suggested seven homologues of MjMCM2 with unknown association to parasitism. Sequence mining revealed two RxLR-like motifs followed by SEED domains in all Meloidogyne spp. MCM2 protein sequences. The unique second RxLR-like motif was absent in other Tylenchida species. Molecular homology modeling of MjMCM2 suggested that second RxLR2-like domain is positioned on a surface loop structure, supporting its function in polar interactions. Our findings reveal a first candidate cell-cycle gene effector in M. javanica—MjMCM2—that is likely secreted into plant host to mimic function of endogenous MCM2.
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Affiliation(s)
- Nathalia Fitoussi
- Department of Entomology, Nematology and Chemistry Units, Agricultural Research Organization (ARO), The Volcani Center, 50250, Bet Dagan, Israel.,Department of Plant Pathology and Microbiology, The Faculty of Agriculture Food and Environment, The Hebrew University of Jerusalem, 76100, Rehovot, Israel
| | | | - Natalia Sichov
- Department of Entomology, Nematology and Chemistry Units, Agricultural Research Organization (ARO), The Volcani Center, 50250, Bet Dagan, Israel
| | - Patricia Bucki
- Department of Entomology, Nematology and Chemistry Units, Agricultural Research Organization (ARO), The Volcani Center, 50250, Bet Dagan, Israel
| | - Noa Sela
- Bioinformatics Unit, Institute of Plant Sciences, Agricultural Research Organization (ARO), The Volcani Center, 50250, Bet Dagan, Israel
| | - Arye Harel
- Bioinformatics Unit, Institute of Plant Sciences, Agricultural Research Organization (ARO), The Volcani Center, 50250, Bet Dagan, Israel
| | - Eduard Belausuv
- Department of Plant Sciences, Agricultural Research Organization (ARO), The Volcani Center, Bet Dagan, Israel
| | - Anil Kumar
- Department of Entomology, Nematology and Chemistry Units, Agricultural Research Organization (ARO), The Volcani Center, 50250, Bet Dagan, Israel
| | - Sigal Brown Miyara
- Department of Entomology, Nematology and Chemistry Units, Agricultural Research Organization (ARO), The Volcani Center, 50250, Bet Dagan, Israel.
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Baris Y, Taylor MRG, Aria V, Yeeles JTP. Fast and efficient DNA replication with purified human proteins. Nature 2022; 606:204-210. [PMID: 35585232 PMCID: PMC7613936 DOI: 10.1038/s41586-022-04759-1] [Citation(s) in RCA: 48] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 04/13/2022] [Indexed: 12/16/2022]
Abstract
Chromosome replication is performed by a complex and intricate ensemble of proteins termed the replisome, where the DNA polymerases Polδ and Polε, DNA polymerase α-primase (Polα) and accessory proteins including AND-1, CLASPIN and TIMELESS-TIPIN (respectively known as Ctf4, Mrc1 and Tof1-Csm3 in Saccharomyces cerevisiae) are organized around the CDC45-MCM-GINS (CMG) replicative helicase1-7. Because a functional human replisome has not been reconstituted from purified proteins, how these factors contribute to human DNA replication and whether additional proteins are required for optimal DNA synthesis are poorly understood. Here we report the biochemical reconstitution of human replisomes that perform fast and efficient DNA replication using 11 purified human replication factors made from 43 polypeptides. Polε, but not Polδ, is crucial for optimal leading-strand synthesis. Unexpectedly, Polε-mediated leading-strand replication is highly dependent on the sliding-clamp processivity factor PCNA and the alternative clamp loader complex CTF18-RFC. We show how CLASPIN and TIMELESS-TIPIN contribute to replisome progression and demonstrate that, in contrast to the budding yeast replisome8, AND-1 directly augments leading-strand replication. Moreover, although AND-1 binds to Polα9,10, the interaction is dispensable for lagging-strand replication, indicating that Polα is functionally recruited via an AND-1-independent mechanism for priming in the human replisome. Collectively, our work reveals how the human replisome achieves fast and efficient leading-strand and lagging-strand DNA replication, and provides a powerful system for future studies of the human replisome and its interactions with other DNA metabolic processes.
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McQuaid ME, Ahmed K, Tran S, Rousseau J, Shaheen R, Kernohan KD, Yuki KE, Grover P, Dreseris ES, Ahmed S, Dupuis L, Stimec J, Shago M, Al-Hassnan ZN, Tremblay R, Maass PG, Wilson MD, Grunebaum E, Boycott KM, Boisvert FM, Maddirevula S, Faqeih EA, Almanjomi F, Khan ZU, Alkuraya FS, Campeau PM, Kannu P, Campos EI, Wurtele H. Hypomorphic GINS3 variants alter DNA replication and cause Meier-Gorlin syndrome. JCI Insight 2022; 7:155648. [PMID: 35603789 PMCID: PMC9215265 DOI: 10.1172/jci.insight.155648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 04/12/2022] [Indexed: 11/17/2022] Open
Abstract
The eukaryotic CDC45/MCM2-7/GINS (CMG) helicase unwinds the DNA double helix during DNA replication. The GINS subcomplex is required for helicase activity and is, therefore, essential for DNA replication and cell viability. Here, we report the identification of 7 individuals from 5 unrelated families presenting with a Meier-Gorlin syndrome–like (MGS-like) phenotype associated with hypomorphic variants of GINS3, a gene not previously associated with this syndrome. We found that MGS-associated GINS3 variants affecting aspartic acid 24 (D24) compromised cell proliferation and caused accumulation of cells in S phase. These variants shortened the protein half-life, altered key protein interactions at the replisome, and negatively influenced DNA replication fork progression. Yeast expressing MGS-associated variants of PSF3 (the yeast GINS3 ortholog) also displayed impaired growth, S phase progression defects, and decreased Psf3 protein stability. We further showed that mouse embryos homozygous for a D24 variant presented intrauterine growth retardation and did not survive to birth, and that fibroblasts derived from these embryos displayed accelerated cellular senescence. Taken together, our findings implicate GINS3 in the pathogenesis of MGS and support the notion that hypomorphic variants identified in this gene impaired cell and organismal growth by compromising DNA replication.
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Affiliation(s)
- Mary E. McQuaid
- Maisonneuve-Rosemont Hospital Research Center, Montreal, Quebec, Canada
| | - Kashif Ahmed
- Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Stephanie Tran
- Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | | | - Ranad Shaheen
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Kristin D. Kernohan
- CHEO Research Institute, Ottawa, Ontario, Canada
- Newborn Screening Ontario, CHEO, Ottawa, Ontario, Canada
| | - Kyoko E. Yuki
- Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Prerna Grover
- Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Ema S. Dreseris
- Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Sameen Ahmed
- Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Lucie Dupuis
- Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Jennifer Stimec
- Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Mary Shago
- Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Zuhair N. Al-Hassnan
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Roch Tremblay
- Maisonneuve-Rosemont Hospital Research Center, Montreal, Quebec, Canada
| | - Philipp G. Maass
- Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Michael D. Wilson
- Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Eyal Grunebaum
- Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, Canada
| | | | | | - Sateesh Maddirevula
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Eissa A. Faqeih
- Section of Medical Genetics, Children’s Specialist Hospital, and
| | - Fahad Almanjomi
- Department of Pediatric Hematology and Oncology, Comprehensive Cancer Center, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Zaheer Ullah Khan
- Department of Pediatric Hematology and Oncology, Comprehensive Cancer Center, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Fowzan S. Alkuraya
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
- Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | | | - Peter Kannu
- Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Medical Genetics, University of Alberta, Edmonton, Alberta, Canada
| | - Eric I. Campos
- Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Hugo Wurtele
- Maisonneuve-Rosemont Hospital Research Center, Montreal, Quebec, Canada
- Department of Medicine, University of Montreal, Montreal, Quebec, Canada
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Schaefer‐Ramadan S, Aleksic J, Al‐Thani NM, Malek JA. Novel protein contact points among TP53 and minichromosome maintenance complex proteins 2, 3, and 5. Cancer Med 2022; 11:4989-5000. [PMID: 35567389 PMCID: PMC9761056 DOI: 10.1002/cam4.4805] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Revised: 04/11/2022] [Accepted: 04/26/2022] [Indexed: 02/03/2023] Open
Abstract
OBJECTIVE Identify protein contact points between TP53 and minichromosome maintenance (MCM) complex proteins 2, 3, and 5 with high resolution allowing for potential novel Cancer drug design. METHODS A next-generation sequencing-based protein-protein interaction method developed in our laboratory called AVA-Seq was applied to a gold-standard human protein interaction set. Proteins including TP53, MCM2, MCM3, MCM5, HSP90AA1, PCNA, NOD1, and others were sheared and ligated into the AVA-Seq system. Protein-protein interactions were then identified in both mild and stringent selective conditions. RESULTS Known interactions among MCM2, MCM3, and MCM5 were identified with the AVA-Seq system. The interacting regions detected between these three proteins overlap with the structural data of the MCM complex, and novel domains were identified with high resolution determined by multiple overlapping fragments. Fragments of wild type TP53 were shown to interact with MCM2, MCM3, and MCM5, and details on the location of the interactions were provided. Finally, a mini-network of known and novel cancer protein interactions was provided, which could have implications for fundamental changes in multiple cancers. CONCLUSION We provide a high-resolution mini-interactome that could direct novel drug targets and implicate possible effects of specific cancer mutations.
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Affiliation(s)
| | - Jovana Aleksic
- Department of Genetic MedicineWeill Cornell Medicine in QatarDohaQatar
| | - Nayra M. Al‐Thani
- Department of Genetic MedicineWeill Cornell Medicine in QatarDohaQatar
| | - Joel A. Malek
- Department of Genetic MedicineWeill Cornell Medicine in QatarDohaQatar
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30
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Saito Y, Santosa V, Ishiguro KI, Kanemaki MT. MCMBP promotes the assembly of the MCM2-7 hetero-hexamer to ensure robust DNA replication in human cells. eLife 2022; 11:77393. [PMID: 35438632 PMCID: PMC9018068 DOI: 10.7554/elife.77393] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Accepted: 04/08/2022] [Indexed: 12/26/2022] Open
Abstract
The MCM2–7 hetero-hexamer is the replicative DNA helicase that plays a central role in eukaryotic DNA replication. In proliferating cells, the expression level of the MCM2–7 hexamer is kept high, which safeguards the integrity of the genome. However, how the MCM2–7 hexamer is assembled in living cells remains unknown. Here, we revealed that the MCM-binding protein (MCMBP) plays a critical role in the assembly of this hexamer in human cells. MCMBP associates with MCM3 which is essential for maintaining the level of the MCM2–7 hexamer. Acute depletion of MCMBP demonstrated that it contributes to MCM2–7 assembly using nascent MCM3. Cells depleted of MCMBP gradually ceased to proliferate because of reduced replication licensing. Under this condition, p53-positive cells exhibited arrest in the G1 phase, whereas p53-null cells entered the S phase and lost their viability because of the accumulation of DNA damage, suggesting that MCMBP is a potential target for killing p53-deficient cancers.
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Affiliation(s)
- Yuichiro Saito
- Department of Chromosome Science, National Institute of Genetics, Research Organization of Information and Systems (ROIS), Mishima, Japan
| | - Venny Santosa
- Department of Chromosome Science, National Institute of Genetics, Research Organization of Information and Systems (ROIS), Mishima, Japan
| | - Kei-Ichiro Ishiguro
- Department of Chromosome Biology, Institute of Molecular Embryology and Genetics (IMEG), Kumamoto University, Kumamoto, Japan
| | - Masato T Kanemaki
- Department of Chromosome Science, National Institute of Genetics, Research Organization of Information and Systems (ROIS), Mishima, Japan.,Department of Genetics, The Graduate University for Advanced Studies (SOKENDAI), Mishima, Japan
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31
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The Involvement of WDHD1 in the Occurrence of Esophageal Cancer as a Downstream Target of PI3K/AKT Pathway. JOURNAL OF ONCOLOGY 2022; 2022:5871188. [PMID: 35422862 PMCID: PMC9005294 DOI: 10.1155/2022/5871188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 03/18/2022] [Indexed: 11/18/2022]
Abstract
Esophageal cancer is one of the most common malignant tumors in the world, which is characterized by high incidence, strong invasiveness, high mortality, and poor prognosis. At present, the therapies include surgery, endoscopic resection, radiotherapy and chemotherapy, targeted therapy, and immunotherapy. The five-year survival rate of esophageal cancer has not been significantly improved, although the medical level has been continuously improved and the management and application of different therapies have been improved day by day. At present, an abnormal gene expression is still regarded as an important factor in the occurrence and development of esophageal cancer. WD repeat and HMG-box DNA binding protein 1(WDHD1), as a key gene, plays an important role in the occurrence of esophageal cancer. It is known that the protein encoded by WDHD1 is the downstream target of the PI3K/AKT pathway. When PI3Ks is activated by extracellular signals, PI(4,5)P2 on the inner side of the plasma membrane will be converted into PI(3,4,5)P3. Then, PI(3,4,5)P3 can be converted into PI(3,4)P2,PI(4)P and PI(3)P by dephosphorylation of some regulatory factors. PI(3,4,5)P3 recruited AKT to the plasma membrane and combined with its pH domain, resulting in conformational change of AKT. Subsequently, AKT was completely activated by PDK1 and PDK2 and begins to move to the cytoplasm and nucleus. In this process, AKT continuously phosphorylates downstream substrates. WDHD1, as a downstream target of AKT, is also phosphorylated and induces DNA replication. Besides the abnormal regulation of cells by other downstream targets of AKT, it also becomes a potential pathway that may eventually lead to the occurrence of esophageal cancer.
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Multiple roles of Pol epsilon in eukaryotic chromosome replication. Biochem Soc Trans 2022; 50:309-320. [PMID: 35129614 PMCID: PMC9022971 DOI: 10.1042/bst20210082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 12/23/2021] [Accepted: 01/06/2022] [Indexed: 11/17/2022]
Abstract
Pol epsilon is a tetrameric assembly that plays distinct roles during eukaryotic chromosome replication. It catalyses leading strand DNA synthesis; yet this function is dispensable for viability. Its non-catalytic domains instead play an essential role in the assembly of the active replicative helicase and origin activation, while non-essential histone-fold subunits serve a critical function in parental histone redeposition onto newly synthesised DNA. Furthermore, Pol epsilon plays a structural role in linking the RFC–Ctf18 clamp loader to the replisome, supporting processive DNA synthesis, DNA damage response signalling as well as sister chromatid cohesion. In this minireview, we discuss recent biochemical and structural work that begins to explain various aspects of eukaryotic chromosome replication, with a focus on the multiple roles of Pol epsilon in this process.
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33
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Lakhera S, Rana M, Devlal K, Celik I, Yadav R. A comprehensive exploration of pharmacological properties, bioactivities and inhibitory potentiality of luteolin from Tridax procumbens as anticancer drug by in-silico approach. Struct Chem 2022; 33:703-719. [PMID: 35106037 PMCID: PMC8795348 DOI: 10.1007/s11224-022-01882-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 01/13/2022] [Indexed: 11/25/2022]
Abstract
Tridax procumbens is a flowering plant of the Asteraceae family with a wide range of medicinal uses like anti-inflammatory, anti-diabetic, anti-microbial, immunomodulatory, etc. This study aimed to investigate the anti-cancerous activity of human lung cancer for targeting luteolin, a phytochemical of Tridax procumbens. The computational study has been done for studying the structural properties of luteolin. The drug-likeness of the molecule has been predicted by virtual screening of ADMET properties. The molecular docking technique of the in-silico method is performed to check the complex formation between protein and ligand. The reactivity and stability of the molecule are investigated with the help of molecular dynamics (MD) simulations. In the present work, we have tried to establish a strong candidature of any of the phytochemical of Tridax Procumbens as an inhibitor against human lung cancer.
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Affiliation(s)
- Shradha Lakhera
- Department of Physics, School of Sciences, Uttarakhand Open University, Haldwani, 263139 Uttarakhand India
| | - Meenakshi Rana
- Department of Physics, School of Sciences, Uttarakhand Open University, Haldwani, 263139 Uttarakhand India
| | - Kamal Devlal
- Department of Physics, School of Sciences, Uttarakhand Open University, Haldwani, 263139 Uttarakhand India
| | - Ismail Celik
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Erciyes University, Kayseri, 38039 Turkey
| | - Rohitash Yadav
- All India Institute of Medical Sciences, Rishikesh, 249203 Uttarakhand India
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He RQ, Li JD, He WY, Chen G, Huang ZG, Li MF, Wu WZ, Chen JT, Pan YQ, Jiang H, Dang YW, Yang LH. Prognosis prediction ability and prospective biological mechanisms of WDHD1 in hepatocellular carcinoma tissues. ELECTRON J BIOTECHN 2022. [DOI: 10.1016/j.ejbt.2021.12.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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35
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Zhou H, Zaher MS, Walter JC, Brown A. Structure of CRL2Lrr1, the E3 ubiquitin ligase that promotes DNA replication termination in vertebrates. Nucleic Acids Res 2021; 49:13194-13206. [PMID: 34850944 PMCID: PMC8682755 DOI: 10.1093/nar/gkab1174] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 11/08/2021] [Accepted: 11/11/2021] [Indexed: 11/17/2022] Open
Abstract
When vertebrate replisomes from neighboring origins converge, the Mcm7 subunit of the replicative helicase, CMG, is ubiquitylated by the E3 ubiquitin ligase, CRL2Lrr1. Polyubiquitylated CMG is then disassembled by the p97 ATPase, leading to replication termination. To avoid premature replisome disassembly, CRL2Lrr1 is only recruited to CMGs after they converge, but the underlying mechanism is unclear. Here, we use cryogenic electron microscopy to determine structures of recombinant Xenopus laevis CRL2Lrr1 with and without neddylation. The structures reveal that CRL2Lrr1 adopts an unusually open architecture, in which the putative substrate-recognition subunit, Lrr1, is located far from the catalytic module that catalyzes ubiquitin transfer. We further demonstrate that a predicted, flexible pleckstrin homology domain at the N-terminus of Lrr1 is essential to target CRL2Lrr1 to terminated CMGs. We propose a hypothetical model that explains how CRL2Lrr1’s catalytic module is positioned next to the ubiquitylation site on Mcm7, and why CRL2Lrr1 binds CMG only after replisomes converge.
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Affiliation(s)
- Haixia Zhou
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA
| | - Manal S Zaher
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA
| | - Johannes C Walter
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA.,Howard Hughes Medical Institute, Boston, MA 02115, USA
| | - Alan Brown
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA
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Jones ML, Baris Y, Taylor MRG, Yeeles JTP. Structure of a human replisome shows the organisation and interactions of a DNA replication machine. EMBO J 2021; 40:e108819. [PMID: 34694004 PMCID: PMC8634136 DOI: 10.15252/embj.2021108819] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 09/28/2021] [Accepted: 09/30/2021] [Indexed: 02/01/2023] Open
Abstract
The human replisome is an elaborate arrangement of molecular machines responsible for accurate chromosome replication. At its heart is the CDC45-MCM-GINS (CMG) helicase, which, in addition to unwinding the parental DNA duplex, arranges many proteins including the leading-strand polymerase Pol ε, together with TIMELESS-TIPIN, CLASPIN and AND-1 that have key and varied roles in maintaining smooth replisome progression. How these proteins are coordinated in the human replisome is poorly understood. We have determined a 3.2 Å cryo-EM structure of a human replisome comprising CMG, Pol ε, TIMELESS-TIPIN, CLASPIN and AND-1 bound to replication fork DNA. The structure permits a detailed understanding of how AND-1, TIMELESS-TIPIN and Pol ε engage CMG, reveals how CLASPIN binds to multiple replisome components and identifies the position of the Pol ε catalytic domain. Furthermore, the intricate network of contacts contributed by MCM subunits and TIMELESS-TIPIN with replication fork DNA suggests a mechanism for strand separation.
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Parvizpour S, Masoudi-Sobhanzadeh Y, Pourseif MM, Barzegari A, Razmara J, Omidi Y. Pharmacoinformatics-based phytochemical screening for anticancer impacts of yellow sweet clover, Melilotus officinalis (Linn.) Pall. Comput Biol Med 2021; 138:104921. [PMID: 34656871 DOI: 10.1016/j.compbiomed.2021.104921] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Revised: 10/03/2021] [Accepted: 10/05/2021] [Indexed: 11/24/2022]
Abstract
To date, much attention has been paid to phytochemicals because of their diverse pharmacological effects on a variety of diseases such as cancer. In this regard, computer-aided drug design, as a cost- and time-effective approach, is primarily applied to investigate the drug candidates before their further costly in vitro and in vivo experimental evaluations. Accordingly, different signaling pathways and proteins can be targeted using such strategies. As a key protein for the initiation of eukaryotic DNA replication, mini-chromosome maintenance complex component 7 (MCM7) overexpression is related to the initiation and progression of aggressive malignancies. The current study was conducted to identify new potential natural compounds from the yellow sweet clover, Melilotus officinalis (Linn.) Pall, by examining the potential of 40 isolated phytochemicals against MCM7 protein. A structure-based pharmacophore model to the protein active site cavity was generated and followed by virtual screening and molecular docking. Overall, four compounds were selected for further evaluation based on their binding affinities. Our analyses revealed that two novel compounds, namely rosmarinic acid (PubChem CID:5281792) and melilotigenin (PubChem CID:14059499) might be druggable and offer safe usage in human. The stability of these two protein-ligand complex structures was confirmed through molecular dynamics simulation. The findings of this study reveal the potential of these two phytochemicals to serve as anticancer agents, while further pharmacological experiments are required to confirm their effectiveness against human cancers.
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Affiliation(s)
- Sepideh Parvizpour
- Research Center for Pharmaceutical Nanotechnology, Biomedicine Institute, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Yosef Masoudi-Sobhanzadeh
- Research Center for Pharmaceutical Nanotechnology, Biomedicine Institute, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mohammad M Pourseif
- Research Center for Pharmaceutical Nanotechnology, Biomedicine Institute, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Abolfazl Barzegari
- Research Center for Pharmaceutical Nanotechnology, Biomedicine Institute, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Jafar Razmara
- Department of Computer Science, Faculty of Mathematics, Statistics, and Computer Science, University of Tabriz, Tabriz, Iran
| | - Yadollah Omidi
- Department of Pharmaceutical Sciences, College of Pharmacy, Nova Southeastern University, Fort Lauderdale, Florida, United States.
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38
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Alshahrani MY, Alshahrani KM, Tasleem M, Akeel A, Almeleebia TM, Ahmad I, Asiri M, Alshahrani NA, Alabdallah NM, Saeed M. Computational Screening of Natural Compounds for Identification of Potential Anti-Cancer Agents Targeting MCM7 Protein. Molecules 2021; 26:molecules26195878. [PMID: 34641424 PMCID: PMC8510405 DOI: 10.3390/molecules26195878] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 09/18/2021] [Accepted: 09/19/2021] [Indexed: 12/12/2022] Open
Abstract
Minichromosome maintenance complex component 7 (MCM7) is involved in replicative licensing and the synthesis of DNA, and its overexpression is a fascinating biomarker for various cancer types. There is currently no effective agent that can prevent the development of cancer caused by the MCM7 protein. However, on the molecular level, inhibiting MCM7 lowers cancer-related cellular growth. With this purpose, this study screened 452 biogenic compounds extracted from the UEFS Natural Products dataset against MCM protein by using the in silico art of technique. The hit compounds UEFS99, UEFS137, and UEFS428 showed good binding with the MCM7 protein with binding energy values of −9.95, −8.92, and −8.71 kcal/mol, which was comparatively higher than that of the control compound ciprofloxacin (−6.50). The hit (UEFS99) with the minimum binding energy was picked for molecular dynamics (MD) simulation investigation, and it demonstrated stability at 30 ns. Computational prediction of physicochemical property evaluation revealed that these hits are non-toxic and have good drug-likeness features. It is suggested that hit compounds UEFS99, UEFS137, and UEFS428 pave the way for further bench work validation in novel inhibitor development against MCM7 to fight the cancers.
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Affiliation(s)
- Mohammad Y. Alshahrani
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, King Khalid University, P.O. Box 61413, Abha 62529, Saudi Arabia; (M.Y.A.); (I.A.); (M.A.)
| | - Kholoud M. Alshahrani
- College of Medicine, King Khalid University Abha, P.O. Box 61413, Abha 62529, Saudi Arabia; (K.M.A.); (N.A.A.)
| | - Munazzah Tasleem
- School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu 610054, China;
| | - Arshiya Akeel
- Department of Botany, Aligarh Muslim University, Aligarh 202002, India
- Correspondence: (A.A.); (M.S.)
| | - Tahani M. Almeleebia
- Department of Clinical Pharmacy, College of Pharmacy, King Khalid University, P.O. Box 61413, Abha 62529, Saudi Arabia;
| | - Irfan Ahmad
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, King Khalid University, P.O. Box 61413, Abha 62529, Saudi Arabia; (M.Y.A.); (I.A.); (M.A.)
| | - Mohammed Asiri
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, King Khalid University, P.O. Box 61413, Abha 62529, Saudi Arabia; (M.Y.A.); (I.A.); (M.A.)
| | - Najla A. Alshahrani
- College of Medicine, King Khalid University Abha, P.O. Box 61413, Abha 62529, Saudi Arabia; (K.M.A.); (N.A.A.)
| | - Nadiyah M. Alabdallah
- Department of Biology, College of Science, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31441, Saudi Arabia;
| | - Mohd Saeed
- Department of Biology, College of Sciences, University of Hail, P.O. Box 2440, Hail 55425, Saudi Arabia
- Correspondence: (A.A.); (M.S.)
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39
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Unwinding of a DNA replication fork by a hexameric viral helicase. Nat Commun 2021; 12:5535. [PMID: 34545080 PMCID: PMC8452682 DOI: 10.1038/s41467-021-25843-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 08/31/2021] [Indexed: 11/16/2022] Open
Abstract
Hexameric helicases are motor proteins that unwind double-stranded DNA (dsDNA) during DNA replication but how they are optimised for strand separation is unclear. Here we present the cryo-EM structure of the full-length E1 helicase from papillomavirus, revealing all arms of a bound DNA replication fork and their interactions with the helicase. The replication fork junction is located at the entrance to the helicase collar ring, that sits above the AAA + motor assembly. dsDNA is escorted to and the 5´ single-stranded DNA (ssDNA) away from the unwinding point by the E1 dsDNA origin binding domains. The 3´ ssDNA interacts with six spirally-arranged β-hairpins and their cyclical top-to-bottom movement pulls the ssDNA through the helicase. Pulling of the RF against the collar ring separates the base-pairs, while modelling of the conformational cycle suggest an accompanying movement of the collar ring has an auxiliary role, helping to make efficient use of ATP in duplex unwinding. Replicative hexameric helicases are fundamental components of replisomes. Here the authors resolve a cryo-EM structure of the E1 helicase from papillomavirus bound to a DNA replication fork, providing insights into the mechanism of DNA unwinding by these hexameric enzymes.
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40
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Guilliam TA. Mechanisms for Maintaining Eukaryotic Replisome Progression in the Presence of DNA Damage. Front Mol Biosci 2021; 8:712971. [PMID: 34295925 PMCID: PMC8290200 DOI: 10.3389/fmolb.2021.712971] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 06/25/2021] [Indexed: 12/04/2022] Open
Abstract
The eukaryotic replisome coordinates template unwinding and nascent-strand synthesis to drive DNA replication fork progression and complete efficient genome duplication. During its advancement along the parental template, each replisome may encounter an array of obstacles including damaged and structured DNA that impede its progression and threaten genome stability. A number of mechanisms exist to permit replisomes to overcome such obstacles, maintain their progression, and prevent fork collapse. A combination of recent advances in structural, biochemical, and single-molecule approaches have illuminated the architecture of the replisome during unperturbed replication, rationalised the impact of impediments to fork progression, and enhanced our understanding of DNA damage tolerance mechanisms and their regulation. This review focusses on these studies to provide an updated overview of the mechanisms that support replisomes to maintain their progression on an imperfect template.
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Affiliation(s)
- Thomas A. Guilliam
- Division of Protein and Nucleic Acid Chemistry, Medical Research Council Laboratory of Molecular Biology, Cambridge, United Kingdom
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41
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Willhoft O, Costa A. A structural framework for DNA replication and transcription through chromatin. Curr Opin Struct Biol 2021; 71:51-58. [PMID: 34218162 DOI: 10.1016/j.sbi.2021.05.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 05/13/2021] [Indexed: 10/21/2022]
Abstract
In eukaryotic cells, DNA replication and transcription machineries uncoil nucleosomes along the double helix, to achieve the exposure of the single-stranded DNA template for nucleic acid synthesis. The replisome and RNA polymerases then redeposit histones onto DNA behind the advancing molecular motor, in a process that is crucial for epigenetic inheritance and homeostasis, respectively. Here, we compare and contrast the mechanisms by which these molecular machines advance through nucleosome arrays and discuss how chromatin remodellers can facilitate DNA replication and transcription.
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Affiliation(s)
- Oliver Willhoft
- Macromolecular Machines Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - Alessandro Costa
- Macromolecular Machines Laboratory, The Francis Crick Institute, London NW1 1AT, UK.
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42
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Meagher M, Spence MN, Enemark EJ. Structure of a dimer of the Sulfolobus solfataricus MCM N-terminal domain reveals a potential role in MCM ring opening. Acta Crystallogr F Struct Biol Commun 2021; 77:177-186. [PMID: 34100776 PMCID: PMC8186412 DOI: 10.1107/s2053230x21005331] [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: 03/10/2021] [Accepted: 05/20/2021] [Indexed: 11/11/2022] Open
Abstract
Cells strongly regulate DNA replication to ensure genomic stability and prevent several diseases, including cancers. Eukaryotes and archaea strictly control DNA-replication initiation by the regulated loading of hexameric minichromosome maintenance (MCM) rings to encircle both strands of the DNA double helix followed by regulated activation of the loaded rings such that they then encircle one DNA strand while excluding the other. Both steps involve an open/closed ring transformation, allowing DNA strands to enter or exit. Here, the crystal structure of a dimer of the N-terminal domain of Sulfolobus solfataricus MCM with an intersubunit interface that is more extensive than in closed-ring structures, while including common interactions to enable facile interconversion, is presented. It is shown that the identified interface could stabilize open MCM rings by compensating for lost interactions at an open neighbor interface and that the prior open-ring cryo-EM structure of MCM loading has a similar extended interface adjacent to its open interface.
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Affiliation(s)
- Martin Meagher
- Structural Biology, St Jude Children’s Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Madison N. Spence
- Structural Biology, St Jude Children’s Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Eric J. Enemark
- Structural Biology, St Jude Children’s Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, 4301 W. Markham Street, Slot 516, Little Rock, AR 72205, USA
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43
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Shyian M, Shore D. Approaching Protein Barriers: Emerging Mechanisms of Replication Pausing in Eukaryotes. Front Cell Dev Biol 2021; 9:672510. [PMID: 34124054 PMCID: PMC8194067 DOI: 10.3389/fcell.2021.672510] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 05/03/2021] [Indexed: 11/13/2022] Open
Abstract
During nuclear DNA replication multiprotein replisome machines have to jointly traverse and duplicate the total length of each chromosome during each cell cycle. At certain genomic locations replisomes encounter tight DNA-protein complexes and slow down. This fork pausing is an active process involving recognition of a protein barrier by the approaching replisome via an evolutionarily conserved Fork Pausing/Protection Complex (FPC). Action of the FPC protects forks from collapse at both programmed and accidental protein barriers, thus promoting genome integrity. In addition, FPC stimulates the DNA replication checkpoint and regulates topological transitions near the replication fork. Eukaryotic cells have been proposed to employ physiological programmed fork pausing for various purposes, such as maintaining copy number at repetitive loci, precluding replication-transcription encounters, regulating kinetochore assembly, or controlling gene conversion events during mating-type switching. Here we review the growing number of approaches used to study replication pausing in vivo and in vitro as well as the characterization of additional factors recently reported to modulate fork pausing in different systems. Specifically, we focus on the positive role of topoisomerases in fork pausing. We describe a model where replisome progression is inherently cautious, which ensures general preservation of fork stability and genome integrity but can also carry out specialized functions at certain loci. Furthermore, we highlight classical and novel outstanding questions in the field and propose venues for addressing them. Given how little is known about replisome pausing at protein barriers in human cells more studies are required to address how conserved these mechanisms are.
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Affiliation(s)
- Maksym Shyian
- Department of Molecular Biology, Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, Geneva, Switzerland
| | - David Shore
- Department of Molecular Biology, Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, Geneva, Switzerland
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44
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Huttlin EL, Bruckner RJ, Navarrete-Perea J, Cannon JR, Baltier K, Gebreab F, Gygi MP, Thornock A, Zarraga G, Tam S, Szpyt J, Gassaway BM, Panov A, Parzen H, Fu S, Golbazi A, Maenpaa E, Stricker K, Guha Thakurta S, Zhang T, Rad R, Pan J, Nusinow DP, Paulo JA, Schweppe DK, Vaites LP, Harper JW, Gygi SP. Dual proteome-scale networks reveal cell-specific remodeling of the human interactome. Cell 2021; 184:3022-3040.e28. [PMID: 33961781 PMCID: PMC8165030 DOI: 10.1016/j.cell.2021.04.011] [Citation(s) in RCA: 398] [Impact Index Per Article: 132.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 01/05/2021] [Accepted: 04/07/2021] [Indexed: 12/16/2022]
Abstract
Thousands of interactions assemble proteins into modules that impart spatial and functional organization to the cellular proteome. Through affinity-purification mass spectrometry, we have created two proteome-scale, cell-line-specific interaction networks. The first, BioPlex 3.0, results from affinity purification of 10,128 human proteins-half the proteome-in 293T cells and includes 118,162 interactions among 14,586 proteins. The second results from 5,522 immunoprecipitations in HCT116 cells. These networks model the interactome whose structure encodes protein function, localization, and complex membership. Comparison across cell lines validates thousands of interactions and reveals extensive customization. Whereas shared interactions reside in core complexes and involve essential proteins, cell-specific interactions link these complexes, "rewiring" subnetworks within each cell's interactome. Interactions covary among proteins of shared function as the proteome remodels to produce each cell's phenotype. Viewable interactively online through BioPlexExplorer, these networks define principles of proteome organization and enable unknown protein characterization.
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Affiliation(s)
- Edward L Huttlin
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
| | - Raphael J Bruckner
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | | | - Joe R Cannon
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Kurt Baltier
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Fana Gebreab
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Melanie P Gygi
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Alexandra Thornock
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Gabriela Zarraga
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Stanley Tam
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - John Szpyt
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Brandon M Gassaway
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Alexandra Panov
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Hannah Parzen
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Sipei Fu
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Arvene Golbazi
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Eila Maenpaa
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Keegan Stricker
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | | | - Tian Zhang
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Ramin Rad
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Joshua Pan
- Broad Institute, Cambridge, MA 02142, USA
| | - David P Nusinow
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Joao A Paulo
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Devin K Schweppe
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | | | - J Wade Harper
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
| | - Steven P Gygi
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
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45
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Henrikus SS, Costa A. Towards a Structural Mechanism for Sister Chromatid Cohesion Establishment at the Eukaryotic Replication Fork. BIOLOGY 2021; 10:466. [PMID: 34073213 PMCID: PMC8229022 DOI: 10.3390/biology10060466] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 05/18/2021] [Accepted: 05/19/2021] [Indexed: 12/23/2022]
Abstract
Cohesion between replicated chromosomes is essential for chromatin dynamics and equal segregation of duplicated genetic material. In the G1 phase, the ring-shaped cohesin complex is loaded onto duplex DNA, enriching at replication start sites, or "origins". During the same phase of the cell cycle, and also at the origin sites, two MCM helicases are loaded as symmetric double hexamers around duplex DNA. During the S phase, and through the action of replication factors, cohesin switches from encircling one parental duplex DNA to topologically enclosing the two duplicated DNA filaments, which are known as sister chromatids. Despite its vital importance, the structural mechanism leading to sister chromatid cohesion establishment at the replication fork is mostly elusive. Here we review the current understanding of the molecular interactions between the replication machinery and cohesin, which support sister chromatid cohesion establishment and cohesin function. In particular, we discuss how cryo-EM is shedding light on the mechanisms of DNA replication and cohesin loading processes. We further expound how frontier cryo-EM approaches, combined with biochemistry and single-molecule fluorescence assays, can lead to understanding the molecular basis of sister chromatid cohesion establishment at the replication fork.
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Affiliation(s)
| | - Alessandro Costa
- Macromolecular Machines Laboratory, The Francis Crick Institute, London NW1 1AT, UK;
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46
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Structural study of the N-terminal domain of human MCM8/9 complex. Structure 2021; 29:1171-1181.e4. [PMID: 34043945 DOI: 10.1016/j.str.2021.05.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Revised: 04/26/2021] [Accepted: 05/07/2021] [Indexed: 11/20/2022]
Abstract
MCM8/9 is a complex involved in homologous recombination (HR) repair pathway. MCM8/9 dysfunction can cause genome instability and result in primary ovarian insufficiency (POI). However, the mechanism underlying these effects is largely unknown. Here, we report crystal structures of the N-terminal domains (NTDs) of MCM8 and MCM9, and build a ring-shaped NTD structure based on a 6.6 Å resolution cryoelectron microscopy map. This shows that the MCM8/9 complex forms a 3:3 heterohexamer in an alternating pattern. A positively charged DNA binding channel and a putative ssDNA exit pathway for fork DNA unwinding are revealed. Based on the atomic model, the potential effects of the clinical POI mutants are interpreted. Surprisingly, the zinc-finger motifs are found to be capable of binding an iron atom as well. Overall, our results provide a model for the formation of the MCM8/9 complex and provide a path for further studies.
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47
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Ahammad F, Alam R, Mahmud R, Akhter S, Talukder EK, Tonmoy AM, Fahim S, Al-Ghamdi K, Samad A, Qadri I. Pharmacoinformatics and molecular dynamics simulation-based phytochemical screening of neem plant (Azadiractha indica) against human cancer by targeting MCM7 protein. Brief Bioinform 2021; 22:6217720. [PMID: 33834183 DOI: 10.1093/bib/bbab098] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 03/02/2021] [Accepted: 03/04/2021] [Indexed: 12/20/2022] Open
Abstract
Minichromosome maintenance complex component 7 (MCM7) belongs to the minichromosome maintenance family that is important for the initiation of eukaryotic DNA replication. Overexpression of the MCM7 protein is relative to cellular proliferation and responsible for aggressive malignancy in various cancers. Mechanistically, inhibition of MCM7 significantly reduces the cellular proliferation associated with cancer. To date, no effective small molecular candidate has been identified that can block the progression of cancer induced by the MCM7 protein. Therefore, the study has been designed to identify small molecular-like natural drug candidates against aggressive malignancy associated with various cancers by targeting MCM7 protein. To identify potential compounds against the targeted protein a comprehensive in silico drug design including molecular docking, ADME (Absorption, Distribution, Metabolism and Excretion), toxicity, and molecular dynamics (MD) simulation approaches has been applied. Seventy phytochemicals isolated from the neem tree (Azadiractha indica) were retrieved and screened against MCM7 protein by using the molecular docking simulation method, where the top four compounds have been chosen for further evaluation based on their binding affinities. Analysis of ADME and toxicity properties reveals the efficacy and safety of the selected four compounds. To validate the stability of the protein-ligand complex structure MD simulations approach has also been performed to the protein-ligand complex structure, which confirmed the stability of the selected three compounds including CAS ID:105377-74-0, CID:12308716 and CID:10505484 to the binding site of the protein. In the study, a comprehensive data screening process has performed based on the docking, ADMET properties, and MD simulation approaches, which found a good value of the selected four compounds against the targeted MCM7 protein and indicates as a promising and effective human anticancer agent.
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Affiliation(s)
- Foysal Ahammad
- Department of Biological Science, Faculty of science, King Abdul-Aziz University, Jeddah-21589, Saudi Arabia.,Laboratory of Computational Biology, Biological Solution Centre (BioSol Centre), Jashore-7408, Bangladesh.,Department of Genetic Engineering and Biotechnology, Faculty of Biological Science and Technology, Jashore University and Science and Technology University, Jashore-7408, Bangladesh
| | - Rahat Alam
- Laboratory of Computational Biology, Biological Solution Centre (BioSol Centre), Jashore-7408, Bangladesh.,Department of Genetic Engineering and Biotechnology, Faculty of Biological Science and Technology, Jashore University and Science and Technology University, Jashore-7408, Bangladesh
| | - Rasel Mahmud
- Department of Pharmacy, Mawlana Bhashani Science and Technology University, Tangail-1902, Bangladesh
| | - Shahina Akhter
- Laboratory of Computational Biology, Biological Solution Centre (BioSol Centre), Jashore-7408, Bangladesh.,Department of Biochemistry and Biotechnology, University of Science and Technology Chittagong (USTC) Block # D, Floor # 11, Foy's Lake, Khulshi, Chittagong 4202, Bangladesh
| | - Enamul Kabir Talukder
- Laboratory of Computational Biology, Biological Solution Centre (BioSol Centre), Jashore-7408, Bangladesh.,Department of Genetic Engineering and Biotechnology, Faculty of Biological Science and Technology, Jashore University and Science and Technology University, Jashore-7408, Bangladesh
| | - Al Mahmud Tonmoy
- Laboratory of Computational Biology, Biological Solution Centre (BioSol Centre), Jashore-7408, Bangladesh.,Department of Zoology, Institute of Dhaka College, University of Dhaka, Dhaka-1000, Bangladesh
| | - Salman Fahim
- Laboratory of Computational Biology, Biological Solution Centre (BioSol Centre), Jashore-7408, Bangladesh.,Bachelor of medicine and Bachelor of Surgery (MBBS), CARe Medical College, 2, 1-A Iqbal Road, Dhaka-1207, Bangladesh
| | - Khalid Al-Ghamdi
- Department of Biological Science, Faculty of science, King Abdul-Aziz University, Jeddah-21589, Saudi Arabia
| | - Abdus Samad
- Laboratory of Computational Biology, Biological Solution Centre (BioSol Centre), Jashore-7408, Bangladesh.,Department of Genetic Engineering and Biotechnology, Faculty of Biological Science and Technology, Jashore University and Science and Technology University, Jashore-7408, Bangladesh
| | - Ishtiaq Qadri
- Department of Biological Science, Faculty of science, King Abdul-Aziz University, Jeddah-21589, Saudi Arabia
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48
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Abstract
The faithful and timely copying of DNA by molecular machines known as replisomes depends on a disparate suite of enzymes and scaffolding factors working together in a highly orchestrated manner. Large, dynamic protein-nucleic acid assemblies that selectively morph between distinct conformations and compositional states underpin this critical cellular process. In this article, we discuss recent progress outlining the physical basis of replisome construction and progression in eukaryotes.
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Affiliation(s)
- Ilan Attali
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, Maryland 21205, USA;
| | - Michael R Botchan
- Department of Molecular and Cell Biology, University of California, Berkeley, California 94720, USA
| | - James M Berger
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, Maryland 21205, USA;
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49
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Zeng T, Guan Y, Li YK, Wu Q, Tang XJ, Zeng X, Ling H, Zou J. The DNA replication regulator MCM6: An emerging cancer biomarker and target. Clin Chim Acta 2021; 517:92-98. [PMID: 33609557 DOI: 10.1016/j.cca.2021.02.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 02/01/2021] [Accepted: 02/05/2021] [Indexed: 01/07/2023]
Abstract
MCM6 is a significant DNA replication regulator that plays a crucial role in sustaining the cell cycle. In many cancer cells, MCM6 expression is enhanced. For example, persistently increased expression of MCM6 promotes the formation, development and progression of hepatocellular carcinoma (HCC). Up- and down-regulation studies have indicated that MCM6 regulates cell cycle, proliferation, metastasis, immune response and the maintenance of the DNA replication system. MCM6 can also regulate downstream signaling such as MEK/ERK thus promoting carcinogenesis. Accordingly, MCM6 may represent a sensitive and specific biomarker to predict adverse progression and poor outcome. Furthermore, inhibition of MCM6 may be an effective cancer treatment. The present review summarizes the latest results on the inactivating and activating functions of MCM6, underlining its function in carcinogenesis. Further studies of the carcinogenic functions of MCM6 may provide novel insight into cancer biology and shed light on new approaches for cancer diagnosis and treatment.
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Affiliation(s)
- Tian Zeng
- Hunan Province Key Laboratory of Tumor Cellular & Molecular Pathology, Cancer Research Institute, University of South China, Hengyang, Hunan 421001, PR China
| | - Yang Guan
- Jiangxi University of Traditional Chinese Medicine, Nanchang, Jiangxi 330000, PR China
| | - Yu-Kun Li
- Hunan Province Key Laboratory of Tumor Cellular & Molecular Pathology, Cancer Research Institute, University of South China, Hengyang, Hunan 421001, PR China
| | - Qing Wu
- Department of Digestive Medical, The Affiliated Nanhua Hospital, University of South China, Hengyang 421002, PR China
| | - Xiao-Jun Tang
- Department of Spinal Surgery, The Second Affiliated Hospital of University of South China, Hengyang, Hunan 421001, PR China
| | - Xin Zeng
- Department of Histology and Embryology, Chongqing Three Gorges Medical College, Wanzhou, Chongqing 404000, PR China
| | - Hui Ling
- Hunan Province Key Laboratory of Tumor Cellular & Molecular Pathology, Cancer Research Institute, University of South China, Hengyang, Hunan 421001, PR China.
| | - Juan Zou
- Hunan Province Key Laboratory of Tumor Cellular & Molecular Pathology, Cancer Research Institute, University of South China, Hengyang, Hunan 421001, PR China.
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Mohammed Khalid AA, Parisse P, Medagli B, Onesti S, Casalis L. Atomic Force Microscopy Investigation of the Interactions between the MCM Helicase and DNA. MATERIALS 2021; 14:ma14030687. [PMID: 33540751 PMCID: PMC7867263 DOI: 10.3390/ma14030687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/21/2021] [Accepted: 01/26/2021] [Indexed: 11/16/2022]
Abstract
The MCM (minichromosome maintenance) protein complex forms an hexameric ring and has a key role in the replication machinery of Eukaryotes and Archaea, where it functions as the replicative helicase opening up the DNA double helix ahead of the polymerases. Here, we present a study of the interaction between DNA and the archaeal MCM complex from Methanothermobacter thermautotrophicus by means of atomic force microscopy (AFM) single molecule imaging. We first optimized the protocol (surface treatment and buffer conditions) to obtain AFM images of surface-equilibrated DNA molecules before and after the interaction with the protein complex. We discriminated between two modes of interaction, one in which the protein induces a sharp bend in the DNA, and one where there is no bending. We found that the presence of the MCM complex also affects the DNA contour length. A possible interpretation of the observed behavior is that in one case the hexameric ring encircles the dsDNA, while in the other the nucleic acid wraps on the outside of the ring, undergoing a change of direction. We confirmed this topographical assignment by testing two mutants, one affecting the N-terminal β-hairpins projecting towards the central channel, and thus preventing DNA loading, the other lacking an external subdomain and thus preventing wrapping. The statistical analysis of the distribution of the protein complexes between the two modes, together with the dissection of the changes of DNA contour length and binding angle upon interaction, for the wild type and the two mutants, is consistent with the hypothesis. We discuss the results in view of the various modes of nucleic acid interactions that have been proposed for both archaeal and eukaryotic MCM complexes.
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Affiliation(s)
- Amna Abdalla Mohammed Khalid
- Elettra-Sincrotrone Trieste, 34149 Trieste, Italy; (A.A.M.K.); (B.M.)
- Department of Physics, PhD School in Nanotechnology, University of Trieste, 34127 Trieste, Italy
| | - Pietro Parisse
- Elettra-Sincrotrone Trieste, 34149 Trieste, Italy; (A.A.M.K.); (B.M.)
- Istituto Officina dei Materiali, Consiglio Nazionale delle Ricerche (IOM-CNR), 34149 Trieste, Italy
- Correspondence: (P.P.); (S.O.); (L.C.)
| | - Barbara Medagli
- Elettra-Sincrotrone Trieste, 34149 Trieste, Italy; (A.A.M.K.); (B.M.)
- Department of Chemical and Pharmaceutical Sciences, University of Trieste, 34127 Trieste, Italy
| | - Silvia Onesti
- Elettra-Sincrotrone Trieste, 34149 Trieste, Italy; (A.A.M.K.); (B.M.)
- Correspondence: (P.P.); (S.O.); (L.C.)
| | - Loredana Casalis
- Elettra-Sincrotrone Trieste, 34149 Trieste, Italy; (A.A.M.K.); (B.M.)
- Correspondence: (P.P.); (S.O.); (L.C.)
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