1
|
Terui R, Berger S, Sambel L, Song D, Chistol G. Single-Molecule Imaging Reveals the Mechanism of Bidirectional Replication Initiation in Metazoa. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.28.587265. [PMID: 38585807 PMCID: PMC10996697 DOI: 10.1101/2024.03.28.587265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Metazoan genomes are copied bidirectionally from thousands of replication origins. Replication initiation entails the assembly and activation of two CMG (Cdc45•Mcm2-7•GINS) helicases at each origin. This requires several firing factors (including TopBP1, RecQL4, DONSON) whose exact roles remain unclear. How two helicases are correctly assembled and activated at every single origin is a long-standing question. By visualizing the recruitment of GINS, Cdc45, TopBP1, RecQL4, and DONSON in real time, we uncovered a surprisingly dynamic picture of initiation. Firing factors transiently bind origins but do not travel with replisomes. Two Cdc45 simultaneously arrive at each origin and two GINS are recruited together, even though neither protein can dimerize. The synchronized delivery of two GINS is mediated by DONSON, which acts as a dimerization scaffold. We show that RecQL4 promotes DONSON dissociation and facilitates helicase activation. The high fidelity of bidirectional origin firing can be explained by a Hopfield-style kinetic proofreading mechanism.
Collapse
Affiliation(s)
- Riki Terui
- Chemical and Systems Biology, Stanford School of Medicine, Stanford CA94305
| | - Scott Berger
- Biophysics Program, Stanford School of Medicine, Stanford CA94305
| | - Larissa Sambel
- Chemical and Systems Biology, Stanford School of Medicine, Stanford CA94305
| | - Dan Song
- Current Address: Eikon Therapeutics Inc
| | - Gheorghe Chistol
- Chemical and Systems Biology, Stanford School of Medicine, Stanford CA94305
- Biophysics Program, Stanford School of Medicine, Stanford CA94305
- Cancer Biology Program, Stanford School of Medicine, Stanford CA94305
- Stanford Cancer Institute, Stanford School of Medicine, Stanford CA94305
- BioX Interdisciplinary Institute, Stanford School of Medicine, Stanford CA94305
| |
Collapse
|
2
|
Bellani MA, Shaik A, Majumdar I, Ling C, Seidman MM. The Response of the Replication Apparatus to Leading Template Strand Blocks. Cells 2023; 12:2607. [PMID: 37998342 PMCID: PMC10670059 DOI: 10.3390/cells12222607] [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: 10/23/2023] [Revised: 11/07/2023] [Accepted: 11/08/2023] [Indexed: 11/25/2023] Open
Abstract
Duplication of the genome requires the replication apparatus to overcome a variety of impediments, including covalent DNA adducts, the most challenging of which is on the leading template strand. Replisomes consist of two functional units, a helicase to unwind DNA and polymerases to synthesize it. The helicase is a multi-protein complex that encircles the leading template strand and makes the first contact with a leading strand adduct. The size of the channel in the helicase would appear to preclude transit by large adducts such as DNA: protein complexes (DPC). Here we discuss some of the extensively studied pathways that support replication restart after replisome encounters with leading template strand adducts. We also call attention to recent work that highlights the tolerance of the helicase for adducts ostensibly too large to pass through the central channel.
Collapse
Affiliation(s)
| | | | | | | | - Michael M. Seidman
- Laboratory of Molecular Biology and Immunology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA; (M.A.B.)
| |
Collapse
|
3
|
Kingsley G, Skagia A, Passaretti P, Fernandez-Cuesta C, Reynolds-Winczura A, Koscielniak K, Gambus A. DONSON facilitates Cdc45 and GINS chromatin association and is essential for DNA replication initiation. Nucleic Acids Res 2023; 51:9748-9763. [PMID: 37638758 PMCID: PMC10570026 DOI: 10.1093/nar/gkad694] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 08/02/2023] [Accepted: 08/17/2023] [Indexed: 08/29/2023] Open
Abstract
Faithful cell division is the basis for the propagation of life and DNA replication must be precisely regulated. DNA replication stress is a prominent endogenous source of genome instability that not only leads to ageing, but also neuropathology and cancer development in humans. Specifically, the issues of how vertebrate cells select and activate origins of replication are of importance as, for example, insufficient origin firing leads to genomic instability and mutations in replication initiation factors lead to the rare human disease Meier-Gorlin syndrome. The mechanism of origin activation has been well characterised and reconstituted in yeast, however, an equal understanding of this process in higher eukaryotes is lacking. The firing of replication origins is driven by S-phase kinases (CDKs and DDK) and results in the activation of the replicative helicase and generation of two bi-directional replication forks. Our data, generated from cell-free Xenopus laevis egg extracts, show that DONSON is required for assembly of the active replicative helicase (CMG complex) at origins during replication initiation. DONSON has previously been shown to be essential during DNA replication, both in human cells and in Drosophila, but the mechanism of DONSON's action was unknown. Here we show that DONSON's presence is essential for replication initiation as it is required for Cdc45 and GINS association with Mcm2-7 complexes and helicase activation. To fulfil this role, DONSON interacts with the initiation factor, TopBP1, in a CDK-dependent manner. Following its initiation role, DONSON also forms a part of the replisome during the elongation stage of DNA replication. Mutations in DONSON have recently been shown to lead to the Meier-Gorlin syndrome; this novel replication initiation role of DONSON therefore provides the explanation for the phenotypes caused by DONSON mutations in patients.
Collapse
Affiliation(s)
- Georgia Kingsley
- Institute of Cancer and Genomic Sciences, Birmingham Centre for Genome Biology, University of Birmingham, UK
| | - Aggeliki Skagia
- Institute of Cancer and Genomic Sciences, Birmingham Centre for Genome Biology, University of Birmingham, UK
| | - Paolo Passaretti
- Institute of Cancer and Genomic Sciences, Birmingham Centre for Genome Biology, University of Birmingham, UK
| | - Cyntia Fernandez-Cuesta
- Institute of Cancer and Genomic Sciences, Birmingham Centre for Genome Biology, University of Birmingham, UK
| | - Alicja Reynolds-Winczura
- Institute of Cancer and Genomic Sciences, Birmingham Centre for Genome Biology, University of Birmingham, UK
| | - Kinga Koscielniak
- Institute of Cancer and Genomic Sciences, Birmingham Centre for Genome Biology, University of Birmingham, UK
| | - Agnieszka Gambus
- Institute of Cancer and Genomic Sciences, Birmingham Centre for Genome Biology, University of Birmingham, UK
| |
Collapse
|
4
|
Zou Y, Pei J, Long H, Lan L, Dong K, Wang T, Li M, Zhao Z, Zhu L, Zhang G, Jin X, Wang Y, Wen Z, Wei M, Feng Y. H4S47 O-GlcNAcylation regulates the activation of mammalian replication origins. Nat Struct Mol Biol 2023:10.1038/s41594-023-00998-6. [PMID: 37202474 DOI: 10.1038/s41594-023-00998-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 04/12/2023] [Indexed: 05/20/2023]
Abstract
The transmission and maintenance of genetic information in eukaryotic cells relies on the faithful duplication of the entire genome. In each round of division, excessive replication origins are licensed, with only a fraction activated to give rise to bi-directional replication forks in the context of chromatin. However, it remains elusive how eukaryotic replication origins are selectively activated. Here we demonstrate that O-GlcNAc transferase (OGT) enhances replication initiation by catalyzing H4S47 O-GlcNAcylation. Mutation of H4S47 impairs DBF4-dependent protein kinase (DDK) recruitment on chromatin, causing reduced phosphorylation of the replicative helicase mini-chromosome maintenance (MCM) complex and compromised DNA unwinding. Our short nascent-strand sequencing results further confirm the importance of H4S47 O-GlcNAcylation in origin activation. We propose that H4S47 O-GlcNAcylation directs origin activation through facilitating MCM phosphorylation, and this may shed light on the control of replication efficiency by chromatin environment.
Collapse
Affiliation(s)
- Yingying Zou
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, Jilin, China
| | - Jiayao Pei
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, Jilin, China
| | - Haizhen Long
- Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen, China
| | - Liting Lan
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Kejian Dong
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, Jilin, China
| | - Tingting Wang
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, Jilin, China
| | - Ming Li
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, Jilin, China
| | - Zhexuan Zhao
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, Jilin, China
| | - Lirun Zhu
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, Jilin, China
| | - Gangxuan Zhang
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, Jilin, China
| | - Xin Jin
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, Jilin, China
| | - Yang Wang
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, Jilin, China
| | - Zengqi Wen
- School of Medicine, Sun Yat-sen University, Shenzhen, China
| | - Min Wei
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, Jilin, China
| | - Yunpeng Feng
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, Jilin, China.
| |
Collapse
|
5
|
Caballero M, Ge T, Rebelo AR, Seo S, Kim S, Brooks K, Zuccaro M, Kanagaraj R, Vershkov D, Kim D, Smogorzewska A, Smolka M, Benvenisty N, West SC, Egli D, Mace EM, Koren A. Comprehensive analysis of DNA replication timing across 184 cell lines suggests a role for MCM10 in replication timing regulation. Hum Mol Genet 2022; 31:2899-2917. [PMID: 35394024 PMCID: PMC9433724 DOI: 10.1093/hmg/ddac082] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 03/18/2022] [Accepted: 04/03/2022] [Indexed: 11/14/2022] Open
Abstract
Cellular proliferation depends on the accurate and timely replication of the genome. Several genetic diseases are caused by mutations in key DNA replication genes; however, it remains unclear whether these genes influence the normal program of DNA replication timing. Similarly, the factors that regulate DNA replication dynamics are poorly understood. To systematically identify trans-acting modulators of replication timing, we profiled replication in 184 cell lines from three cell types, encompassing 60 different gene knockouts or genetic diseases. Through a rigorous approach that considers the background variability of replication timing, we concluded that most samples displayed normal replication timing. However, mutations in two genes showed consistently abnormal replication timing. The first gene was RIF1, a known modulator of replication timing. The second was MCM10, a highly conserved member of the pre-replication complex. Cells from a single patient carrying MCM10 mutations demonstrated replication timing variability comprising 46% of the genome and at different locations than RIF1 knockouts. Replication timing alterations in the mutated MCM10 cells were predominantly comprised of replication delays and initiation site gains and losses. Taken together, this study demonstrates the remarkable robustness of the human replication timing program and reveals MCM10 as a novel candidate modulator of DNA replication timing.
Collapse
Affiliation(s)
- Madison Caballero
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Tiffany Ge
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Ana Rita Rebelo
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Seungmae Seo
- Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Sean Kim
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Kayla Brooks
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Michael Zuccaro
- Department of Pediatrics and Naomi Berrie Diabetes Center, Columbia University, New York, NY 10032, USA
- Columbia University Stem Cell Initiative, New York, NY 10032, USA
| | | | - Dan Vershkov
- The Azrieli Center for Stem Cells and Genetic Research, Department of Genetics, Silberman Institute of Life Sciences, The Hebrew University, Jerusalem 91904, Israel
| | - Dongsung Kim
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, USA
| | - Agata Smogorzewska
- Laboratory of Genome Maintenance, The Rockefeller University, New York, NY, USA
| | - Marcus Smolka
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, USA
| | - Nissim Benvenisty
- The Azrieli Center for Stem Cells and Genetic Research, Department of Genetics, Silberman Institute of Life Sciences, The Hebrew University, Jerusalem 91904, Israel
| | | | - Dieter Egli
- Department of Pediatrics and Naomi Berrie Diabetes Center, Columbia University, New York, NY 10032, USA
- Columbia University Stem Cell Initiative, New York, NY 10032, USA
| | - Emily M Mace
- Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Amnon Koren
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| |
Collapse
|
6
|
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.
Collapse
|
7
|
Xu X, Chang CW, Li M, Liu C, Liu Y. Molecular Mechanisms of the RECQ4 Pathogenic Mutations. Front Mol Biosci 2021; 8:791194. [PMID: 34869606 PMCID: PMC8637615 DOI: 10.3389/fmolb.2021.791194] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 11/02/2021] [Indexed: 12/03/2022] Open
Abstract
The human RECQ4 gene encodes an ATP-dependent DNA helicase that contains a conserved superfamily II helicase domain located at the center of the polypeptide. RECQ4 is one of the five RECQ homologs in human cells, and its helicase domain is flanked by the unique amino and carboxyl termini with sequences distinct from other members of the RECQ helicases. Since the identification of the RECQ4 gene in 1998, multiple RECQ4 mutations have been linked to the pathogenesis of three clinical diseases, which are Rothmund-Thomson syndrome, Baller-Gerold syndrome, and RAPADILINO. Patients with these diseases show various developmental abnormalities. In addition, a subset of RECQ4 mutations are associated with high cancer risks, especially for osteosarcoma and/or lymphoma at early ages. The discovery of clinically relevant RECQ4 mutations leads to intriguing questions: how is the RECQ4 helicase responsible for preventing multiple clinical syndromes? What are the mechanisms by which the RECQ4 disease mutations cause tissue abnormalities and drive cancer formation? Furthermore, RECQ4 is highly overexpressed in many cancer types, raising the question whether RECQ4 acts not only as a tumor suppressor but also an oncogene that can be a potential new therapeutic target. Defining the molecular dysfunctions of different RECQ4 disease mutations is imperative to improving our understanding of the complexity of RECQ4 clinical phenotypes and the dynamic roles of RECQ4 in cancer development and prevention. We will review recent progress in examining the molecular and biochemical properties of the different domains of the RECQ4 protein. We will shed light on how the dynamic roles of RECQ4 in human cells may contribute to the complexity of RECQ4 clinical phenotypes.
Collapse
Affiliation(s)
- Xiaohua Xu
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, Duarte, CA, United States
| | - Chou-Wei Chang
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, Duarte, CA, United States
| | - Min Li
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, Duarte, CA, United States
| | - Chao Liu
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, Duarte, CA, United States
| | - Yilun Liu
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, Duarte, CA, United States
| |
Collapse
|
8
|
Volpi I, Gillespie PJ, Chadha GS, Blow JJ. The role of DDK and Treslin-MTBP in coordinating replication licensing and pre-initiation complex formation. Open Biol 2021; 11:210121. [PMID: 34699733 PMCID: PMC8548084 DOI: 10.1098/rsob.210121] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 09/21/2021] [Indexed: 01/04/2023] Open
Abstract
Treslin/Ticrr is required for the initiation of DNA replication and binds to MTBP (Mdm2 Binding Protein). Here, we show that in Xenopus egg extract, MTBP forms an elongated tetramer with Treslin containing two molecules of each protein. Immunodepletion and add-back experiments show that Treslin-MTBP is rate limiting for replication initiation. It is recruited onto chromatin before S phase starts and recruitment continues during S phase. We show that DDK activity both increases and strengthens the interaction of Treslin-MTBP with licensed chromatin. We also show that DDK activity cooperates with CDK activity to drive the interaction of Treslin-MTBP with TopBP1 which is a regulated crucial step in pre-initiation complex formation. These results suggest how DDK works together with CDKs to regulate Treslin-MTBP and plays a crucial in selecting which origins will undergo initiation.
Collapse
Affiliation(s)
- Ilaria Volpi
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Peter J. Gillespie
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Gaganmeet Singh Chadha
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - J. Julian Blow
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| |
Collapse
|
9
|
Balajee AS. Human RecQL4 as a Novel Molecular Target for Cancer Therapy. Cytogenet Genome Res 2021; 161:305-327. [PMID: 34474412 DOI: 10.1159/000516568] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 02/24/2021] [Indexed: 11/19/2022] Open
Abstract
Human RecQ helicases play diverse roles in the maintenance of genomic stability. Inactivating mutations in 3 of the 5 human RecQ helicases are responsible for the pathogenesis of Werner syndrome (WS), Bloom syndrome (BS), Rothmund-Thomson syndrome (RTS), RAPADILINO, and Baller-Gerold syndrome (BGS). WS, BS, and RTS patients are at increased risk for developing many age-associated diseases including cancer. Mutations in RecQL1 and RecQL5 have not yet been associated with any human diseases so far. In terms of disease outcome, RecQL4 deserves special attention because mutations in RecQL4 result in 3 autosomal recessive syndromes (RTS type II, RAPADILINO, and BGS). RecQL4, like other human RecQ helicases, has been demonstrated to play a crucial role in the maintenance of genomic stability through participation in diverse DNA metabolic activities. Increased incidence of osteosarcoma in RecQL4-mutated RTS patients and elevated expression of RecQL4 in sporadic cancers including osteosarcoma suggest that loss or gain of RecQL4 expression is linked with cancer susceptibility. In this review, current and future perspectives are discussed on the potential use of RecQL4 as a novel cancer therapeutic target.
Collapse
Affiliation(s)
- Adayabalam S Balajee
- Cytogenetic Biodosimetry Laboratory, Radiation Emergency Assistance Center/Training Site, Oak Ridge Institute for Science and Education, Oak Ridge Associated Universities, Oak Ridge, Tennessee, USA
| |
Collapse
|
10
|
Chang CW, Xu X, Li M, Xin D, Ding L, Wang YT, Liu Y. Pathogenic mutations reveal a role of RECQ4 in mitochondrial RNA:DNA hybrid formation and resolution. Sci Rep 2020; 10:17033. [PMID: 33046774 PMCID: PMC7552406 DOI: 10.1038/s41598-020-74095-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 09/21/2020] [Indexed: 11/09/2022] Open
Abstract
The synthesis of mitochondrial DNA (mtDNA) is a complex process that involves the formation and resolution of unusual nucleic acid structures, such as RNA:DNA hybrids. However, little is known about the enzymes that regulate these processes. RECQ4 is a DNA replication factor important for mtDNA maintenance, and here, we unveil a role of human RECQ4 in regulating the formation and resolution of mitochondrial RNA:DNA hybrids. Mitochondrial membrane protein p32 can block mtDNA synthesis by restricting RECQ4 mitochondrial localization via protein–protein interaction. We found that the interaction with p32 was disrupted not only by the previously reported cancer-associated RECQ4 mutation, del(A420-A463), but also by a clinical mutation of the adjacent residue, P466L. Surprisingly, although P466L mutant was present in the mitochondria at greater levels, unlike del(A420-A463) mutant, it failed to enhance mtDNA synthesis due to the accumulation of RNA:DNA hybrids throughout the mtDNA. Biochemical analysis revealed that P466L mutation enhanced RECQ4 annealing activity to generate RNA:DNA hybrids at the same time reduced its unwinding activity to resolve this structure. Hence, P466L mutation led to a reduced efficiency in completing mtDNA synthesis due to unresolved RNA:DNA hybrids across mtDNA.
Collapse
Affiliation(s)
- Chou-Wei Chang
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, Duarte, CA, 91010-3000, USA
| | - Xiaohua Xu
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, Duarte, CA, 91010-3000, USA
| | - Min Li
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, Duarte, CA, 91010-3000, USA
| | - Di Xin
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, Duarte, CA, 91010-3000, USA
| | - Lin Ding
- J. Craig Venter Institute, San Diego, CA, 92037, USA
| | - Ya-Ting Wang
- Memorial Sloan Kettering, New York, NY, 10065, USA
| | - Yilun Liu
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, Duarte, CA, 91010-3000, USA.
| |
Collapse
|
11
|
Duan S, Han X, Akbari M, Croteau DL, Rasmussen LJ, Bohr VA. Interaction between RECQL4 and OGG1 promotes repair of oxidative base lesion 8-oxoG and is regulated by SIRT1 deacetylase. Nucleic Acids Res 2020; 48:6530-6546. [PMID: 32432680 PMCID: PMC7337523 DOI: 10.1093/nar/gkaa392] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 04/14/2020] [Accepted: 05/04/2020] [Indexed: 12/17/2022] Open
Abstract
OGG1 initiated base excision repair (BER) is the major pathway for repair of oxidative DNA base damage 8-oxoguanine (8-oxoG). Here, we report that RECQL4 DNA helicase, deficient in the cancer-prone and premature aging Rothmund-Thomson syndrome, physically and functionally interacts with OGG1. RECQL4 promotes catalytic activity of OGG1 and RECQL4 deficiency results in defective 8-oxoG repair and increased genomic 8-oxoG. Furthermore, we show that acute oxidative stress leads to increased RECQL4 acetylation and its interaction with OGG1. The NAD+-dependent protein SIRT1 deacetylates RECQL4 in vitro and in cells thereby controlling the interaction between OGG1 and RECQL4 after DNA repair and maintaining RECQL4 in a low acetylated state. Collectively, we find that RECQL4 is involved in 8-oxoG repair through interaction with OGG1, and that SIRT1 indirectly modulates BER of 8-oxoG by controlling RECQL4–OGG1 interaction.
Collapse
Affiliation(s)
- Shunlei Duan
- Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Xuerui Han
- Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Mansour Akbari
- Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Deborah L Croteau
- Laboratory of Molecular Gerontology, National Institute on Aging, 251 Bayview Blvd, Baltimore, MD, 21224, USA
| | - Lene Juel Rasmussen
- Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Vilhelm A Bohr
- Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, DK-2200 Copenhagen, Denmark.,Laboratory of Molecular Gerontology, National Institute on Aging, 251 Bayview Blvd, Baltimore, MD, 21224, USA
| |
Collapse
|
12
|
Lu L, Jin W, Wang LL. RECQ DNA Helicases and Osteosarcoma. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1258:37-54. [PMID: 32767233 DOI: 10.1007/978-3-030-43085-6_3] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The RECQ family of DNA helicases is a conserved group of enzymes that plays an important role in maintaining genomic stability. Humans possess five RECQ helicase genes, and mutations in three of them - BLM, WRN, and RECQL4 - are associated with the genetic disorders Bloom syndrome, Werner syndrome, and Rothmund-Thomson syndrome (RTS), respectively. These syndromes share overlapping clinical features, and importantly they are all associated with an increased risk of cancer. Patients with RTS have the highest specific risk of developing osteosarcoma compared to all other cancer predisposition syndromes; therefore, RTS serves as a relevant model to study the pathogenesis and molecular genetics of osteosarcoma. The "tumor suppressor" function of the RECQ helicases continues to be an area of active investigation. This chapter will focus primarily on the known cellular functions of RECQL4 and how these may relate to tumorigenesis, as well as ongoing efforts to understand RECQL4's functions in vivo using animal models. Understanding the RECQ pathways will provide insight into avenues for novel cancer therapies in the future.
Collapse
Affiliation(s)
- Linchao Lu
- Department of Pediatrics, Section of Hematology/Oncology, Texas Children's Cancer Center, Baylor College of Medicine, Houston, TX, USA.
| | - Weidong Jin
- Department of Pediatrics, Section of Hematology/Oncology, Texas Children's Cancer Center, Baylor College of Medicine, Houston, TX, USA
| | - Lisa L Wang
- Department of Pediatrics, Section of Hematology/Oncology, Texas Children's Cancer Center, Baylor College of Medicine, Houston, TX, USA.
| |
Collapse
|
13
|
Shin G, Jeong D, Kim H, Im JS, Lee JK. RecQL4 tethering on the pre-replicative complex induces unscheduled origin activation and replication stress in human cells. J Biol Chem 2019; 294:16255-16265. [PMID: 31519754 DOI: 10.1074/jbc.ra119.009996] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 09/09/2019] [Indexed: 12/15/2022] Open
Abstract
Sequential activation of DNA replication origins is precisely programmed and critical to maintaining genome stability. RecQL4, a member of the conserved RecQ family of helicases, plays an essential role in the initiation of DNA replication in mammalian cells. Here, we showed that RecQL4 protein tethered on the pre-replicative complex (pre-RC) induces early activation of late replicating origins during S phase. Tethering of RecQL4 or its N terminus on pre-RCs via fusion with Orc4 protein resulted in the recruitment of essential initiation factors, such as Mcm10, And-1, Cdc45, and GINS, increasing nascent DNA synthesis in late replicating origins during early S phase. In this origin activation process, tethered RecQL4 was able to recruit Cdc45 even in the absence of cyclin-dependent kinase (CDK) activity, whereas CDK phosphorylation of RecQL4 N terminus was required for interaction with and origin recruitment of And-1 and GINS. In addition, forced activation of replication origins by RecQL4 tethering resulted in increased replication stress and the accumulation of ssDNAs, which can be recovered by transcription inhibition. Collectively, these results suggest that recruitment of RecQL4 to replication origins is an important step for temporal activation of replication origins during S phase. Further, perturbation of replication timing control by unscheduled origin activation significantly induces replication stress, which is mostly caused by transcription-replication conflicts.
Collapse
Affiliation(s)
- Gwangsu Shin
- Interdisciplinary Graduate Program in Genetic Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Dongsoo Jeong
- Interdisciplinary Graduate Program in Genetic Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Hyunsup Kim
- Interdisciplinary Graduate Program in Genetic Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Jun-Sub Im
- Department of Biology Education, Seoul National University, Seoul, 08826, Republic of Korea
| | - Joon-Kyu Lee
- Interdisciplinary Graduate Program in Genetic Engineering, Seoul National University, Seoul, 08826, Republic of Korea .,Department of Biology Education, Seoul National University, Seoul, 08826, Republic of Korea
| |
Collapse
|
14
|
Park SY, Kim H, Im JS, Lee JK. ATM activation is impaired in human cells defective in RecQL4 helicase activity. Biochem Biophys Res Commun 2019; 509:379-383. [PMID: 30594395 DOI: 10.1016/j.bbrc.2018.12.151] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2018] [Accepted: 12/20/2018] [Indexed: 11/26/2022]
Abstract
RecQL4 has been shown to be involved in DNA replication and repair, but its role in DNA damage checkpoint pathway has not been reported. Here, we show that RecQL4 plays an important role in the activation of ataxia telangiectasia mutated (ATM)-dependent checkpoint pathway in human cells. Cells depleted with RecQL4 or Rothmund-Thomson syndrome cells showed significant impairment in the activation of ATM and the downstream effector proteins such as checkpoint kinase 2 and p53 after DNA damage. This defect was recovered with the expression of wild type RecQL4 but not any mutant RecQL4 proteins with defective helicase activities. While RecQL4 failed to show any direct interaction with ATM, it stably interacted with the Mre11-Rad50-Nbs1 complex that is essential for the activation of ATM and was localized on the DNA damage foci. Thus, our results suggest that the helicase activity of RecQL4 plays an important role in the activation of ATM-dependent checkpoint pathway against DNA double strand breaks in human cells.
Collapse
Affiliation(s)
- Soon-Young Park
- Department of Biology Education, Seoul National University, Seoul, 08826, South Korea
| | - Hyunsup Kim
- Interdisciplinary Graduate Program in Genetic Engineering, Seoul National University, Seoul, 08826, South Korea
| | - Jun-Sub Im
- Department of Biology Education, Seoul National University, Seoul, 08826, South Korea
| | - Joon-Kyu Lee
- Department of Biology Education, Seoul National University, Seoul, 08826, South Korea; Interdisciplinary Graduate Program in Genetic Engineering, Seoul National University, Seoul, 08826, South Korea.
| |
Collapse
|
15
|
Cui F, Hu J, Ning S, Tan J, Tang H. Overexpression of MCM10 promotes cell proliferation and predicts poor prognosis in prostate cancer. Prostate 2018; 78:1299-1310. [PMID: 30095171 PMCID: PMC6282949 DOI: 10.1002/pros.23703] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 07/13/2018] [Indexed: 12/25/2022]
Abstract
BACKGROUND Prostate cancer (PCa) is one of the most malignant tumors of the male urogenital system. There is an urgent need to identify novel biomarkers for PCa. METHODS In this study, we evaluated the expression levels of MCM10 in prostate cancer by analyzing public datasets (including The Cancer Genome Atlas and GSE21032). Furthermore, loss of function assays was performed to evaluate the effects of MCM10 on cell proliferation, apoptosis, and colony formation. Furthermore, we performed microarray and bioinformatics analyses to explore the potential mechanisms of MCM10. RESULTS In the present study, we for the first time revealed MCM10 was significantly upregulated in PCa. Moreover, we found increased MCM10 expression was significantly associated with advanced clinical stage and high Gleason score PCa. Kaplan-Meier analysis demonstrated higher MCM10 expression was associated with a poorer patient prognosis in PCa. Furthermore, loss of function assays showed that MCM10 knockdown inhibited cell proliferation and colony formation, but promoted cell apoptosis. Additionally, we performed microarray and bioinformatics analysis and found MCM10 regulated PCa progression by regulating a series of biological processes including cancer, cell death, and apoptosis. CONCLUSIONS These results suggest that MCM10 may be a potential diagnostic and therapeutic target for PCa.
Collapse
Affiliation(s)
- Feilun Cui
- Department of UrologyThe Affiliated People's Hospital of Jiangsu UniversityZhenjiangJiangsuP.R. China
| | - Jianpeng Hu
- Department of UrologyThe Affiliated People's Hospital of Jiangsu UniversityZhenjiangJiangsuP.R. China
| | - Songyi Ning
- Medical College of Jiangsu UniversityZhenjiangJiangsuP.R. China
| | - Jian Tan
- Department of UrologyThe Affiliated People's Hospital of Jiangsu UniversityZhenjiangJiangsuP.R. China
| | - Huaming Tang
- Department of UrologyThe Affiliated People's Hospital of Jiangsu UniversityZhenjiangJiangsuP.R. China
| |
Collapse
|
16
|
Moiseeva TN, Bakkenist CJ. Regulation of the initiation of DNA replication in human cells. DNA Repair (Amst) 2018; 72:99-106. [PMID: 30266203 DOI: 10.1016/j.dnarep.2018.09.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 09/07/2018] [Indexed: 12/31/2022]
Abstract
The origin of species would not have been possible without high fidelity DNA replication and complex genomes evolved with mechanisms that control the initiation of DNA replication at multiple origins on multiple chromosomes such that the genome is duplicated once and only once. The mechanisms that control the assembly and activation of the replicative helicase and the initiation of DNA replication in yeast and Xenopus egg extract systems have been identified and reviewed [1,2]. The goal of this review is to organize currently available data on the mechanisms that control the initiation of DNA replication in human cells.
Collapse
Affiliation(s)
- Tatiana N Moiseeva
- Department of Radiation Oncology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
| | - Christopher J Bakkenist
- Department of Radiation Oncology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA; Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| |
Collapse
|
17
|
Mo D, Zhao Y, Balajee AS. Human RecQL4 helicase plays multifaceted roles in the genomic stability of normal and cancer cells. Cancer Lett 2017; 413:1-10. [PMID: 29080750 DOI: 10.1016/j.canlet.2017.10.021] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 10/13/2017] [Accepted: 10/16/2017] [Indexed: 02/06/2023]
Abstract
Human RecQ helicases that share homology with E. coli RecQ helicase play critical roles in diverse biological activities such as DNA replication, transcription, recombination and repair. Mutations in three of the five human RecQ helicases (RecQ1, WRN, BLM, RecQL4 and RecQ5) result in autosomal recessive syndromes characterized by accelerated aging symptoms and cancer incidence. Mutational inactivation of Werner (WRN) and Bloom (BLM) genes results in Werner syndrome (WS) and Bloom syndrome (BS) respectively. However, mutations in RecQL4 result in three human disorders: (I) Rothmund-Thomson syndrome (RTS), (II) RAPADILINO and (III) Baller-Gerold syndrome (BGS). Cells from WS, BS and RTS are characterized by a unique chromosomal anomaly indicating that each of the RecQ helicases performs specialized function(s) in a non-redundant manner. Elucidating the biological functions of RecQ helicases will enable us to understand not only the aging process but also to determine the cause for age-associated human diseases. Recent biochemical and molecular studies have given new insights into the multifaceted roles of RecQL4 that range from genomic stability to carcinogenesis and beyond. This review summarizes some of the existing and emerging knowledge on diverse biological functions of RecQL4 and its significance as a potential molecular target for cancer therapy.
Collapse
Affiliation(s)
- Dongliang Mo
- Chinese Academy of Science, Beijing Institute of Genomics, Beijing CN 100029, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yongliang Zhao
- Chinese Academy of Science, Beijing Institute of Genomics, Beijing CN 100029, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Adayabalam S Balajee
- Radiation Emergency Assistance Center and Training Site, Oak Ridge Associated Universities, Oak Ridge Institute for Science and Education, Oak Ridge, TN 37830, USA.
| |
Collapse
|
18
|
Trakselis MA, Seidman MM, Brosh RM. Mechanistic insights into how CMG helicase facilitates replication past DNA roadblocks. DNA Repair (Amst) 2017; 55:76-82. [PMID: 28554039 DOI: 10.1016/j.dnarep.2017.05.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 05/13/2017] [Indexed: 02/07/2023]
Abstract
Before leaving the house, it is a good idea to check for road closures that may affect the morning commute. Otherwise, one may encounter significant delays arriving at the destination. While this is commonly true, motorists may be able to consult a live interactive traffic map and pick an alternate route or detour to avoid being late. However, this is not the case if one needs to catch the train which follows a single track to the terminus; if something blocks the track, there is a delay. Such is the case for the DNA replisome responsible for copying the genetic information that provides the recipe of life. When the replication machinery encounters a DNA roadblock, the outcome can be devastating if the obstacle is not overcome in an efficient manner. Fortunately, the cell's DNA synthesis apparatus can bypass certain DNA obstructions, but the mechanism(s) are still poorly understood. Very recently, two papers from the O'Donnell lab, one structural (Georgescu et al., 2017 [1]) and the other biochemical (Langston and O'Donnell, 2017 [2]), have challenged the conventional thinking of how the replicative CMG helicase is arranged on DNA, unwinds double-stranded DNA, and handles barricades in its path. These new findings raise important questions in the search for mechanistic insights into how DNA is copied, particularly when the replication machinery encounters a roadblock.
Collapse
Affiliation(s)
- Michael A Trakselis
- Department of Chemistry and Biochemistry, Baylor University, One Bear Place #97348, Waco, TX 76798-7348, United States.
| | - Michael M Seidman
- Laboratory of Molecular Gerontology, National Institute on Aging, NIH, 251 Bayview Blvd, Baltimore, MD 21224, United States.
| | - Robert M Brosh
- Laboratory of Molecular Gerontology, National Institute on Aging, NIH, 251 Bayview Blvd, Baltimore, MD 21224, United States.
| |
Collapse
|
19
|
Mcm10: A Dynamic Scaffold at Eukaryotic Replication Forks. Genes (Basel) 2017; 8:genes8020073. [PMID: 28218679 PMCID: PMC5333062 DOI: 10.3390/genes8020073] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 02/09/2017] [Accepted: 02/09/2017] [Indexed: 12/13/2022] Open
Abstract
To complete the duplication of large genomes efficiently, mechanisms have evolved that coordinate DNA unwinding with DNA synthesis and provide quality control measures prior to cell division. Minichromosome maintenance protein 10 (Mcm10) is a conserved component of the eukaryotic replisome that contributes to this process in multiple ways. Mcm10 promotes the initiation of DNA replication through direct interactions with the cell division cycle 45 (Cdc45)-minichromosome maintenance complex proteins 2-7 (Mcm2-7)-go-ichi-ni-san GINS complex proteins, as well as single- and double-stranded DNA. After origin firing, Mcm10 controls replication fork stability to support elongation, primarily facilitating Okazaki fragment synthesis through recruitment of DNA polymerase-α and proliferating cell nuclear antigen. Based on its multivalent properties, Mcm10 serves as an essential scaffold to promote DNA replication and guard against replication stress. Under pathological conditions, Mcm10 is often dysregulated. Genetic amplification and/or overexpression of MCM10 are common in cancer, and can serve as a strong prognostic marker of poor survival. These findings are compatible with a heightened requirement for Mcm10 in transformed cells to overcome limitations for DNA replication dictated by altered cell cycle control. In this review, we highlight advances in our understanding of when, where and how Mcm10 functions within the replisome to protect against barriers that cause incomplete replication.
Collapse
|
20
|
Aladjem MI, Redon CE. Order from clutter: selective interactions at mammalian replication origins. Nat Rev Genet 2017; 18:101-116. [PMID: 27867195 PMCID: PMC6596300 DOI: 10.1038/nrg.2016.141] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Mammalian chromosome duplication progresses in a precise order and is subject to constraints that are often relaxed in developmental disorders and malignancies. Molecular information about the regulation of DNA replication at the chromatin level is lacking because protein complexes that initiate replication seem to bind chromatin indiscriminately. High-throughput sequencing and mathematical modelling have yielded detailed genome-wide replication initiation maps. Combining these maps and models with functional genetic analyses suggests that distinct DNA-protein interactions at subgroups of replication initiation sites (replication origins) modulate the ubiquitous replication machinery and supports an emerging model that delineates how indiscriminate DNA-binding patterns translate into a consistent, organized replication programme.
Collapse
Affiliation(s)
- Mirit I Aladjem
- Developmental Therapeutics Branch, Center for Cancer Research, National Cancer Institute, 37 Convent Drive, Bethesda, Maryland 20892, USA
| | - Christophe E Redon
- Developmental Therapeutics Branch, Center for Cancer Research, National Cancer Institute, 37 Convent Drive, Bethesda, Maryland 20892, USA
| |
Collapse
|
21
|
Lu L, Jin W, Wang LL. Aging in Rothmund-Thomson syndrome and related RECQL4 genetic disorders. Ageing Res Rev 2017; 33:30-35. [PMID: 27287744 DOI: 10.1016/j.arr.2016.06.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 06/03/2016] [Accepted: 06/06/2016] [Indexed: 01/21/2023]
Abstract
Rothmund-Thomson Syndrome (RTS) is a rare autosomal recessive disease which manifests several clinical features of accelerated aging. These findings include atrophic skin and pigment changes, alopecia, osteopenia, cataracts, and an increased incidence of cancer for patients carrying RECQL4 germline mutations. Mutations in RECQL4 are responsible for the majority of cases of RTS. RECQL4 belongs to RECQ DNA helicase family which has been shown to participate in many aspects of DNA metabolism. In the past several years, accumulated evidence indicates that RECQL4 is important not only in cancer development but also in the aging process. In this review, based on recent research data, we summarize the common aging findings in RTS patients and propose possible mechanisms to explain the aging features in these patients.
Collapse
Affiliation(s)
- Linchao Lu
- Texas Children's Cancer Center, Department of Pediatrics, Section of Hematology/Oncology, Baylor College of Medicine, 1102 Bates Avenue, Suite 1200, Houston, TX 77030, USA
| | - Weidong Jin
- Texas Children's Cancer Center, Department of Pediatrics, Section of Hematology/Oncology, Baylor College of Medicine, 1102 Bates Avenue, Suite 1200, Houston, TX 77030, USA
| | - Lisa L Wang
- Texas Children's Cancer Center, Department of Pediatrics, Section of Hematology/Oncology, Baylor College of Medicine, 1102 Bates Avenue, Suite 1200, Houston, TX 77030, USA.
| |
Collapse
|
22
|
Targeted inhibition of WRN helicase, replication stress and cancer. Biochim Biophys Acta Rev Cancer 2016; 1867:42-48. [PMID: 27902925 DOI: 10.1016/j.bbcan.2016.11.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 11/16/2016] [Accepted: 11/24/2016] [Indexed: 11/21/2022]
Abstract
WRN helicase has several roles in genome maintenance, such as replication, base excision repair, recombination, DNA damage response and transcription. These processes are often found upregulated in human cancers, many of which display increased levels of WRN. Therefore, directed inhibition of this RecQ helicase could be beneficial to selective cancer therapy. Inhibition of WRN is feasible by the use of small-molecule inhibitors or application of RNA interference and EGS/RNase P targeting systems. Remarkably, helicase depletion leads to a severe reduction in cell viability due to mitotic catastrophe, which is triggered by replication stress induced by DNA repair failure and fork progression arrest. Moreover, we present new evidence that WRN depletion results in early changes of RNA polymerase III and RNase P activities, thereby implicating chromatin-associated tRNA enzymes in WRN-related stress response. Combined with the recently discovered roles of RecQ helicases in cancer, current data support the targeting prospect of these genome guardians, as a means of developing clinical phases aimed at diminishing adaptive resistance to present targeted therapies.
Collapse
|
23
|
Distinct functions of human RecQ helicases during DNA replication. Biophys Chem 2016; 225:20-26. [PMID: 27876204 DOI: 10.1016/j.bpc.2016.11.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 11/13/2016] [Accepted: 11/13/2016] [Indexed: 12/31/2022]
Abstract
DNA replication is the most vulnerable process of DNA metabolism in proliferating cells and therefore it is tightly controlled and coordinated with processes that maintain genomic stability. Human RecQ helicases are among the most important factors involved in the maintenance of replication fork integrity, especially under conditions of replication stress. RecQ helicases promote recovery of replication forks being stalled due to different replication roadblocks of either exogenous or endogenous source. They prevent generation of aberrant replication fork structures and replication fork collapse, and are involved in proper checkpoint signaling. The essential role of human RecQ helicases in the genome maintenance during DNA replication is underlined by association of defects in their function with cancer predisposition.
Collapse
|
24
|
Interaction of RECQ4 and MCM10 is important for efficient DNA replication origin firing in human cells. Oncotarget 2016; 6:40464-79. [PMID: 26588054 PMCID: PMC4747346 DOI: 10.18632/oncotarget.6342] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 11/10/2015] [Indexed: 12/17/2022] Open
Abstract
DNA replication is a highly coordinated process that is initiated at multiple replication origins in eukaryotes. These origins are bound by the origin recognition complex (ORC), which subsequently recruits the Mcm2-7 replicative helicase in a Cdt1/Cdc6-dependent manner. In budding yeast, two essential replication factors, Sld2 and Mcm10, are then important for the activation of replication origins. In humans, the putative Sld2 homolog, RECQ4, interacts with MCM10. Here, we have identified two mutants of human RECQ4 that are deficient in binding to MCM10. We show that these RECQ4 variants are able to complement the lethality of an avian cell RECQ4 deletion mutant, indicating that the essential function of RECQ4 in vertebrates is unlikely to require binding to MCM10. Nevertheless, we show that the RECQ4-MCM10 interaction is important for efficient replication origin firing.
Collapse
|
25
|
Lionaki E, Gkikas I, Tavernarakis N. Differential Protein Distribution between the Nucleus and Mitochondria: Implications in Aging. Front Genet 2016; 7:162. [PMID: 27695477 PMCID: PMC5025450 DOI: 10.3389/fgene.2016.00162] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 09/01/2016] [Indexed: 01/05/2023] Open
Abstract
The coordination of nuclear and mitochondrial genomes plays a pivotal role in maintenance of mitochondrial biogenesis and functionality during stress and aging. Environmental and cellular inputs signal to nucleus and/or mitochondria to trigger interorganellar compensatory responses. Loss of this tightly orchestrated coordination results in loss of cellular homeostasis and underlies various pathologies and age-related diseases. Several signaling cascades that govern interorganellar communication have been revealed up to now, and have been classified as part of the anterograde (nucleus to mitochondria) or retrograde (mitochondrial to nucleus) response. Many of these molecular pathways rely on the dual distribution of nuclear or mitochondrial components under basal or stress conditions. These dually localized components usually engage in specific tasks in their primary organelle of function, whilst upon cellular stimuli, they appear in the other organelle where they engage in the same or a different task, triggering a compensatory stress response. In this review, we focus on protein factors distributed between the nucleus and mitochondria and activated to exert their functions upon basal or stress conditions. We further discuss implications of bi-organellar targeting in the context of aging.
Collapse
Affiliation(s)
- Eirini Lionaki
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas Heraklion, Greece
| | - Ilias Gkikas
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas Heraklion, Greece
| | - Nektarios Tavernarakis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-HellasHeraklion, Greece; Department of Basic Sciences, Faculty of Medicine, University of CreteHeraklion, Greece
| |
Collapse
|
26
|
Chadha GS, Gambus A, Gillespie PJ, Blow JJ. Xenopus Mcm10 is a CDK-substrate required for replication fork stability. Cell Cycle 2016; 15:2183-2195. [PMID: 27327991 PMCID: PMC4993430 DOI: 10.1080/15384101.2016.1199305] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 06/01/2016] [Accepted: 06/03/2016] [Indexed: 12/17/2022] Open
Abstract
During S phase, following activation of the S phase CDKs and the DBF4-dependent kinases (DDK), double hexamers of Mcm2-7 at licensed replication origins are activated to form the core replicative helicase. Mcm10 is one of several proteins that have been implicated from work in yeasts to play a role in forming a mature replisome during the initiation process. Mcm10 has also been proposed to play a role in promoting replisome stability after initiation has taken place. The role of Mcm10 is particularly unclear in metazoans, where conflicting data has been presented. Here, we investigate the role and regulation of Mcm10 in Xenopus egg extracts. We show that Xenopus Mcm10 is recruited to chromatin late in the process of replication initiation and this requires prior action of DDKs and CDKs. We also provide evidence that Mcm10 is a CDK substrate but does not need to be phosphorylated in order to associate with chromatin. We show that in extracts depleted of more than 99% of Mcm10, the bulk of DNA replication still occurs, suggesting that Mcm10 is not required for the process of replication initiation. However, in extracts depleted of Mcm10, the replication fork elongation rate is reduced. Furthermore, the absence of Mcm10 or its phosphorylation by CDK results in instability of replisome proteins on DNA, which is particularly important under conditions of replication stress.
Collapse
Affiliation(s)
- Gaganmeet Singh Chadha
- a Centre for Gene Regulation & Expression, School of Life Sciences, University of Dundee , Dundee , UK
| | - Agnieszka Gambus
- a Centre for Gene Regulation & Expression, School of Life Sciences, University of Dundee , Dundee , UK
| | - Peter J Gillespie
- a Centre for Gene Regulation & Expression, School of Life Sciences, University of Dundee , Dundee , UK
| | - J Julian Blow
- a Centre for Gene Regulation & Expression, School of Life Sciences, University of Dundee , Dundee , UK
| |
Collapse
|
27
|
Affiliation(s)
- Hisao Masai
- a Department of Genome Medicine; The Tokyo Metropolitan Institute of Medical Science ; Setagaya-ku , Tokyo , Japan
| |
Collapse
|
28
|
Ding L, Liu Y. Borrowing nuclear DNA helicases to protect mitochondrial DNA. Int J Mol Sci 2015; 16:10870-87. [PMID: 25984607 PMCID: PMC4463680 DOI: 10.3390/ijms160510870] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 05/09/2015] [Accepted: 05/11/2015] [Indexed: 01/20/2023] Open
Abstract
In normal cells, mitochondria are the primary organelles that generate energy, which is critical for cellular metabolism. Mitochondrial dysfunction, caused by mitochondrial DNA (mtDNA) mutations or an abnormal mtDNA copy number, is linked to a range of human diseases, including Alzheimer's disease, premature aging and cancer. mtDNA resides in the mitochondrial lumen, and its duplication requires the mtDNA replicative helicase, Twinkle. In addition to Twinkle, many DNA helicases, which are encoded by the nuclear genome and are crucial for nuclear genome integrity, are transported into the mitochondrion to also function in mtDNA replication and repair. To date, these helicases include RecQ-like helicase 4 (RECQ4), petite integration frequency 1 (PIF1), DNA replication helicase/nuclease 2 (DNA2) and suppressor of var1 3-like protein 1 (SUV3). Although the nuclear functions of some of these DNA helicases have been extensively studied, the regulation of their mitochondrial transport and the mechanisms by which they contribute to mtDNA synthesis and maintenance remain largely unknown. In this review, we attempt to summarize recent research progress on the role of mammalian DNA helicases in mitochondrial genome maintenance and the effects on mitochondria-associated diseases.
Collapse
Affiliation(s)
- Lin Ding
- Department of Radiation Biology, Beckman Research Institute, City of Hope, Duarte, CA 91010-3000, USA.
| | - Yilun Liu
- Department of Radiation Biology, Beckman Research Institute, City of Hope, Duarte, CA 91010-3000, USA.
| |
Collapse
|