1
|
Huynh O, Ruis K, Montales K, Michael WM. NBS1 binds directly to TOPBP1 via disparate interactions between the NBS1 BRCT1 domain and the TOPBP1 BRCT1 and BRCT2 domains. DNA Repair (Amst) 2023; 123:103461. [PMID: 36738687 PMCID: PMC9992324 DOI: 10.1016/j.dnarep.2023.103461] [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: 08/26/2022] [Revised: 01/20/2023] [Accepted: 01/26/2023] [Indexed: 02/05/2023]
Abstract
The TOPBP1 and NBS1 proteins are key components of DNA repair and DNA-based signaling systems. TOPBP1 is a multi-BRCT domain containing protein that plays important roles in checkpoint signaling, DNA replication, and DNA repair. Likewise, NBS1, which is a component of the MRE11-RAD50-NBS1 (MRN) complex, functions in both checkpoint signaling and DNA repair. NBS1 also contains BRCT domains, and previous works have shown that TOPBP1 and NBS1 interact with one another. In this work we examine the interaction between TOPBP1 and NBS1 in detail. We report that NBS1 uses its BRCT1 domain to interact with TOPBP1's BRCT1 domain and, separately, with TOPBP1's BRCT2 domain. Thus, NBS1 can make two distinct contacts with TOPBP1. We report that recombinant TOPBP1 and NBS1 proteins bind one another in a purified system, showing that the interaction is direct and does not require post-translational modifications. Surprisingly, we also report that intact BRCT domains are not required for these interactions, as truncated versions of the domains are sufficient to confer binding. For TOPBP1, we find that small 24-29 amino acid sequences within BRCT1 or BRCT2 allow binding to NBS1, in a transferrable manner. These data expand our knowledge of how the crucial DNA damage response proteins TOPBP1 and NBS1 interact with one another and set the stage for functional analysis of the two disparate binding sites for NBS1 on TOPBP1.
Collapse
Affiliation(s)
- Oanh Huynh
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Kenna Ruis
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Katrina Montales
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - W Matthew Michael
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA.
| |
Collapse
|
2
|
Prabhakar AT, James CD, Das D, Otoa R, Day M, Burgner J, Fontan CT, Wang X, Glass SH, Wieland A, Donaldson MM, Bristol ML, Li R, Oliver AW, Pearl LH, Smith BO, Morgan IM. CK2 Phosphorylation of Human Papillomavirus 16 E2 on Serine 23 Promotes Interaction with TopBP1 and Is Critical for E2 Interaction with Mitotic Chromatin and the Viral Life Cycle. mBio 2021; 12:e0116321. [PMID: 34544280 PMCID: PMC8546539 DOI: 10.1128/mbio.01163-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Accepted: 08/19/2021] [Indexed: 01/05/2023] Open
Abstract
During the human papillomavirus 16 (HPV16) life cycle, the E2 protein interacts with host factors to regulate viral transcription, replication, and genome segregation/retention. Our understanding of host partner proteins and their roles in E2 functions remains incomplete. Here we demonstrate that CK2 phosphorylation of E2 on serine 23 promotes interaction with TopBP1 in vitro and in vivo and that E2 is phosphorylated on this residue during the HPV16 life cycle. We investigated the consequences of mutating serine 23 on E2 functions. E2-S23A (E2 with serine 23 mutated to alanine) activates and represses transcription identically to E2-WT (wild-type E2), and E2-S23A is as efficient as E2-WT in transient replication assays. However, E2-S23A has compromised interaction with mitotic chromatin compared with E2-WT. In E2-WT cells, both E2 and TopBP1 levels increase during mitosis compared with vector control cells. In E2-S23A cells, neither E2 nor TopBP1 levels increase during mitosis. Introduction of the S23A mutation into the HPV16 genome resulted in delayed immortalization of human foreskin keratinocytes (HFK) and higher episomal viral genome copy number in resulting established HFK. Remarkably, S23A cells had a disrupted viral life cycle in organotypic raft cultures, with a loss of E2 expression and a failure of viral replication. Overall, our results demonstrate that CK2 phosphorylation of E2 on serine 23 promotes interaction with TopBP1 and that this interaction is critical for the viral life cycle. IMPORTANCE Human papillomaviruses are causative agents in around 5% of all cancers, with no specific antiviral therapeutics available for treating infections or resultant cancers. In this report, we demonstrate that phosphorylation of HPV16 E2 by CK2 promotes formation of a complex with the cellular protein TopBP1 in vitro and in vivo. This complex results in stabilization of E2 during mitosis. We demonstrate that CK2 phosphorylates E2 on serine 23 in vivo and that CK2 inhibitors disrupt the E2-TopBP1 complex. Mutation of E2 serine 23 to alanine disrupts the HPV16 life cycle, hindering immortalization and disrupting the viral life cycle, demonstrating a critical function for this residue.
Collapse
Affiliation(s)
- Apurva T. Prabhakar
- Virginia Commonwealth University (VCU), Philips Institute for Oral Health Research, School of Dentistry, Richmond, Virginia, USA
| | - Claire D. James
- Virginia Commonwealth University (VCU), Philips Institute for Oral Health Research, School of Dentistry, Richmond, Virginia, USA
| | - Dipon Das
- Virginia Commonwealth University (VCU), Philips Institute for Oral Health Research, School of Dentistry, Richmond, Virginia, USA
| | - Raymonde Otoa
- Virginia Commonwealth University (VCU), Philips Institute for Oral Health Research, School of Dentistry, Richmond, Virginia, USA
| | - Matthew Day
- Cancer Research UK DNA Repair Enzymes Group, Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton, United Kingdom
| | - John Burgner
- Virginia Commonwealth University (VCU), Philips Institute for Oral Health Research, School of Dentistry, Richmond, Virginia, USA
| | - Christian T. Fontan
- Virginia Commonwealth University (VCU), Philips Institute for Oral Health Research, School of Dentistry, Richmond, Virginia, USA
| | - Xu Wang
- Virginia Commonwealth University (VCU), Philips Institute for Oral Health Research, School of Dentistry, Richmond, Virginia, USA
| | - Sarah H. Glass
- VCU School of Dentistry, Department of Oral Diagnostic Sciences, Richmond, Virginia, USA
| | - Andreas Wieland
- Emory Vaccine Center, Emory University School of Medicine, Atlanta, Georgia, USA
- Department of Microbiology & Immunology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Mary M. Donaldson
- School of Veterinary Medicine, University of Glasgow, Bearsden, United Kingdom
| | - Molly L. Bristol
- Virginia Commonwealth University (VCU), Philips Institute for Oral Health Research, School of Dentistry, Richmond, Virginia, USA
| | - Renfeng Li
- Virginia Commonwealth University (VCU), Philips Institute for Oral Health Research, School of Dentistry, Richmond, Virginia, USA
- VCU Massey Cancer Center, Richmond, Virginia, USA
| | - Anthony W. Oliver
- Cancer Research UK DNA Repair Enzymes Group, Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton, United Kingdom
| | - Laurence H. Pearl
- Cancer Research UK DNA Repair Enzymes Group, Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton, United Kingdom
| | - Brian O. Smith
- Institute of Molecular, Cell & Systems Biology, University of Glasgow, Glasgow, United Kingdom
| | - Iain M. Morgan
- Virginia Commonwealth University (VCU), Philips Institute for Oral Health Research, School of Dentistry, Richmond, Virginia, USA
- VCU Massey Cancer Center, Richmond, Virginia, USA
| |
Collapse
|
3
|
Wenmaekers S, Viergever BJ, Kumar G, Kranenburg O, Black PC, Daugaard M, Meijer RP. A Potential Role for HUWE1 in Modulating Cisplatin Sensitivity. Cells 2021; 10:cells10051262. [PMID: 34065298 PMCID: PMC8160634 DOI: 10.3390/cells10051262] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 05/17/2021] [Accepted: 05/18/2021] [Indexed: 12/25/2022] Open
Abstract
Cisplatin is a widely used antineoplastic agent, whose efficacy is limited by primary and acquired therapeutic resistance. Recently, a bladder cancer genome-wide CRISPR/Cas9 knock-out screen correlated cisplatin sensitivity to multiple genetic biomarkers. Among the screen’s top hits was the HECT domain-containing ubiquitin E3 ligase (HUWE1). In this review, HUWE1 is postulated as a therapeutic response modulator, affecting the collision between platinum-DNA adducts and the replication fork, the primary cytotoxic action of platins. HUWE1 can alter the cytotoxic response to platins by targeting essential components of the DNA damage response including BRCA1, p53, and Mcl-1. Deficiency of HUWE1 could lead to enhanced DNA damage repair and a dysfunctional apoptotic apparatus, thereby inducing resistance to platins. Future research on the relationship between HUWE1 and platins could generate new mechanistic insights into therapy resistance. Ultimately, HUWE1 might serve as a clinical biomarker to tailor cancer treatment strategies, thereby improving cancer care and patient outcomes.
Collapse
Affiliation(s)
- Stijn Wenmaekers
- Laboratory Translational Oncology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands; (S.W.); (B.J.V.); (O.K.)
- Department of Oncological Urology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
| | - Bastiaan J. Viergever
- Laboratory Translational Oncology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands; (S.W.); (B.J.V.); (O.K.)
- Department of Oncological Urology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
| | - Gunjan Kumar
- Department of Urologic Sciences, University of British Columbia, Vancouver, BC V5Z 1M9, Canada; (G.K.); (P.C.B.)
- Vancouver Prostate Centre, Vancouver, BC V6H 3Z6, Canada
| | - Onno Kranenburg
- Laboratory Translational Oncology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands; (S.W.); (B.J.V.); (O.K.)
| | - Peter C. Black
- Department of Urologic Sciences, University of British Columbia, Vancouver, BC V5Z 1M9, Canada; (G.K.); (P.C.B.)
- Vancouver Prostate Centre, Vancouver, BC V6H 3Z6, Canada
| | - Mads Daugaard
- Department of Urologic Sciences, University of British Columbia, Vancouver, BC V5Z 1M9, Canada; (G.K.); (P.C.B.)
- Vancouver Prostate Centre, Vancouver, BC V6H 3Z6, Canada
- Correspondence: (M.D.); (R.P.M.)
| | - Richard P. Meijer
- Laboratory Translational Oncology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands; (S.W.); (B.J.V.); (O.K.)
- Department of Oncological Urology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
- Correspondence: (M.D.); (R.P.M.)
| |
Collapse
|
4
|
Taiana E, Ronchetti D, Todoerti K, Nobili L, Tassone P, Amodio N, Neri A. LncRNA NEAT1 in Paraspeckles: A Structural Scaffold for Cellular DNA Damage Response Systems? Noncoding RNA 2020; 6:ncrna6030026. [PMID: 32630183 PMCID: PMC7549348 DOI: 10.3390/ncrna6030026] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 06/25/2020] [Accepted: 06/28/2020] [Indexed: 12/13/2022] Open
Abstract
Nuclear paraspeckle assembly transcript 1 (NEAT1) is a long non-coding RNA (lncRNA) reported to be frequently deregulated in various types of cancers and neurodegenerative processes. NEAT1 is an indispensable structural component of paraspeckles (PSs), which are dynamic and membraneless nuclear bodies that affect different cellular functions, including stress response. Furthermore, increasing evidence supports the crucial role of NEAT1 and essential structural proteins of PSs (PSPs) in the regulation of the DNA damage repair (DDR) system. This review aims to provide an overview of the current knowledge on the involvement of NEAT1 and PSPs in DDR, which might strengthen the rationale underlying future NEAT1-based therapeutic options in tumor and neurodegenerative diseases.
Collapse
Affiliation(s)
- Elisa Taiana
- Department of Oncology and Hemato-oncology, University of Milan, 20122 Milan, Italy; (D.R.); (L.N.)
- Hematology, Fondazione Cà Granda IRCCS Policlinico, 20122 Milan, Italy;
- Correspondence: (E.T.); (A.N.); Tel.: +39-02-5032-0420 (E.T. & A.N.)
| | - Domenica Ronchetti
- Department of Oncology and Hemato-oncology, University of Milan, 20122 Milan, Italy; (D.R.); (L.N.)
- Hematology, Fondazione Cà Granda IRCCS Policlinico, 20122 Milan, Italy;
| | - Katia Todoerti
- Hematology, Fondazione Cà Granda IRCCS Policlinico, 20122 Milan, Italy;
| | - Lucia Nobili
- Department of Oncology and Hemato-oncology, University of Milan, 20122 Milan, Italy; (D.R.); (L.N.)
| | - Pierfrancesco Tassone
- Department of Experimental and Clinical Medicine, Magna Graecia University of Catanzaro, 88100 Catanzaro, Italy; (P.T.); (N.A.)
| | - Nicola Amodio
- Department of Experimental and Clinical Medicine, Magna Graecia University of Catanzaro, 88100 Catanzaro, Italy; (P.T.); (N.A.)
| | - Antonino Neri
- Department of Oncology and Hemato-oncology, University of Milan, 20122 Milan, Italy; (D.R.); (L.N.)
- Hematology, Fondazione Cà Granda IRCCS Policlinico, 20122 Milan, Italy;
- Correspondence: (E.T.); (A.N.); Tel.: +39-02-5032-0420 (E.T. & A.N.)
| |
Collapse
|
5
|
Mooser C, Symeonidou IE, Leimbacher PA, Ribeiro A, Shorrocks AMK, Jungmichel S, Larsen SC, Knechtle K, Jasrotia A, Zurbriggen D, Jeanrenaud A, Leikauf C, Fink D, Nielsen ML, Blackford AN, Stucki M. Treacle controls the nucleolar response to rDNA breaks via TOPBP1 recruitment and ATR activation. Nat Commun 2020; 11:123. [PMID: 31913317 PMCID: PMC6949271 DOI: 10.1038/s41467-019-13981-x] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 12/10/2019] [Indexed: 01/10/2023] Open
Abstract
Induction of DNA double-strand breaks (DSBs) in ribosomal DNA (rDNA) repeats is associated with ATM-dependent repression of ribosomal RNA synthesis and large-scale reorganization of nucleolar architecture, but the signaling events that regulate these responses are largely elusive. Here we show that the nucleolar response to rDNA breaks is dependent on both ATM and ATR activity. We further demonstrate that ATM- and NBS1-dependent recruitment of TOPBP1 in the nucleoli is required for inhibition of ribosomal RNA synthesis and nucleolar segregation in response to rDNA breaks. Mechanistically, TOPBP1 recruitment is mediated by phosphorylation-dependent interactions between three of its BRCT domains and conserved phosphorylated Ser/Thr residues at the C-terminus of the nucleolar phosphoprotein Treacle. Our data thus reveal an important cooperation between TOPBP1 and Treacle in the signaling cascade that triggers transcriptional inhibition and nucleolar segregation in response to rDNA breaks.
Collapse
Affiliation(s)
- Clémence Mooser
- Department of Gynecology, University of Zurich, Wagistrasse 14, CH-8952, Schlieren, Switzerland
| | - Ioanna-Eleni Symeonidou
- Department of Gynecology, University of Zurich, Wagistrasse 14, CH-8952, Schlieren, Switzerland
| | - Pia-Amata Leimbacher
- Department of Gynecology, University of Zurich, Wagistrasse 14, CH-8952, Schlieren, Switzerland
| | - Alison Ribeiro
- Department of Gynecology, University of Zurich, Wagistrasse 14, CH-8952, Schlieren, Switzerland
| | - Ann-Marie K Shorrocks
- Department of Oncology, Medical Research Council Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, OX3 9DS, UK
- Cancer Research UK/Medical Research Council Oxford Institute for Radiation Oncology, University of Oxford, Oxford, OX3 7DQ, UK
| | - Stephanie Jungmichel
- The Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Faculty of Health and Medical Sciences, Bledgamsvej 3B DK-2200, Copenhagen, Denmark
| | - Sara C Larsen
- The Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Faculty of Health and Medical Sciences, Bledgamsvej 3B DK-2200, Copenhagen, Denmark
| | - Katja Knechtle
- Department of Gynecology, University of Zurich, Wagistrasse 14, CH-8952, Schlieren, Switzerland
| | - Arti Jasrotia
- Department of Gynecology, University of Zurich, Wagistrasse 14, CH-8952, Schlieren, Switzerland
| | - Diana Zurbriggen
- Department of Gynecology, University of Zurich, Wagistrasse 14, CH-8952, Schlieren, Switzerland
| | - Alain Jeanrenaud
- Department of Gynecology, University of Zurich, Wagistrasse 14, CH-8952, Schlieren, Switzerland
| | - Colin Leikauf
- Department of Gynecology, University of Zurich, Wagistrasse 14, CH-8952, Schlieren, Switzerland
| | - Daniel Fink
- Department of Gynecology, University of Zurich, Wagistrasse 14, CH-8952, Schlieren, Switzerland
| | - Michael L Nielsen
- The Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Faculty of Health and Medical Sciences, Bledgamsvej 3B DK-2200, Copenhagen, Denmark
| | - Andrew N Blackford
- Department of Oncology, Medical Research Council Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, OX3 9DS, UK
- Cancer Research UK/Medical Research Council Oxford Institute for Radiation Oncology, University of Oxford, Oxford, OX3 7DQ, UK
| | - Manuel Stucki
- Department of Gynecology, University of Zurich, Wagistrasse 14, CH-8952, Schlieren, Switzerland.
| |
Collapse
|
6
|
Ding L, Madamsetty VS, Kiers S, Alekhina O, Ugolkov A, Dube J, Zhang Y, Zhang JS, Wang E, Dutta SK, Schmitt DM, Giles FJ, Kozikowski AP, Mazar AP, Mukhopadhyay D, Billadeau DD. Glycogen Synthase Kinase-3 Inhibition Sensitizes Pancreatic Cancer Cells to Chemotherapy by Abrogating the TopBP1/ATR-Mediated DNA Damage Response. Clin Cancer Res 2019; 25:6452-6462. [PMID: 31533931 DOI: 10.1158/1078-0432.ccr-19-0799] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 06/03/2019] [Accepted: 08/02/2019] [Indexed: 02/06/2023]
Abstract
PURPOSE Pancreatic ductal adenocarcinoma (PDAC) is a predominantly fatal common malignancy with inadequate treatment options. Glycogen synthase kinase 3β (GSK-3β) is an emerging target in human malignancies including PDAC.Experimental Design: Pancreatic cancer cell lines and patient-derived xenografts were treated with a novel GSK-3 inhibitor 9-ING-41 alone or in combination with chemotherapy. Activation of the DNA damage response pathway and S-phase arrest induced by gemcitabine were assessed in pancreatic tumor cells with pharmacologic inhibition or siRNA depletion of GSK-3 kinases by immunoblotting, flow cytometry, and immunofluorescence. RESULTS 9-ING-41 treatment significantly increased pancreatic tumor cell killing when combined with chemotherapy. Inhibition of GSK-3 by 9-ING-41 prevented gemcitabine-induced S-phase arrest suggesting an impact on the ATR-mediated DNA damage response. Both 9-ING-41 and siRNA depletion of GSK-3 kinases impaired the activation of ATR leading to the phosphorylation and activation of Chk1. Mechanistically, depletion or knockdown of GSK-3 kinases resulted in the degradation of the ATR-interacting protein TopBP1, thus limiting the activation of ATR in response to single-strand DNA damage. CONCLUSIONS These data identify a previously unknown role for GSK-3 kinases in the regulation of the TopBP1/ATR/Chk1 DNA damage response pathway. The data also support the inclusion of patients with PDAC in clinical studies of 9-ING-41 alone and in combination with gemcitabine.
Collapse
Affiliation(s)
- Li Ding
- The Division of Oncology Research, Schulze Center for Novel Therapeutics, Mayo Clinic, Rochester, Minnesota
| | - Vijay S Madamsetty
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Jacksonville, Florida
| | - Spencer Kiers
- The Division of Oncology Research, Schulze Center for Novel Therapeutics, Mayo Clinic, Rochester, Minnesota
| | - Olga Alekhina
- The Division of Oncology Research, Schulze Center for Novel Therapeutics, Mayo Clinic, Rochester, Minnesota
| | | | - John Dube
- The Division of Oncology Research, Schulze Center for Novel Therapeutics, Mayo Clinic, Rochester, Minnesota
| | - Yu Zhang
- The Division of Oncology Research, Schulze Center for Novel Therapeutics, Mayo Clinic, Rochester, Minnesota
| | - Jin-San Zhang
- The Division of Oncology Research, Schulze Center for Novel Therapeutics, Mayo Clinic, Rochester, Minnesota.,Center for Precision Medicine, The First Affiliated Hospital of Wenzhou Medical University, Institute of Life Science, Wenzhou University, Zhejiang, China
| | - Enfeng Wang
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Jacksonville, Florida
| | - Shamit K Dutta
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Jacksonville, Florida
| | | | | | | | | | | | - Daniel D Billadeau
- The Division of Oncology Research, Schulze Center for Novel Therapeutics, Mayo Clinic, Rochester, Minnesota.
| |
Collapse
|
7
|
Das D, Bristol ML, Smith NW, James CD, Wang X, Pichierri P, Morgan IM. Werner Helicase Control of Human Papillomavirus 16 E1-E2 DNA Replication Is Regulated by SIRT1 Deacetylation. mBio 2019; 10:e00263-19. [PMID: 30890607 PMCID: PMC6426601 DOI: 10.1128/mbio.00263-19] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 02/04/2019] [Indexed: 01/03/2023] Open
Abstract
Human papillomaviruses (HPV) are double-stranded DNA viruses causative in a host of human diseases, including several cancers. Following infection, two viral proteins, E1 and E2, activate viral replication in association with cellular factors and stimulate the DNA damage response (DDR) during the replication process. E1-E2 uses homologous recombination (HR) to facilitate DNA replication, but an understanding of host factors involved in this process remains incomplete. Previously, we demonstrated that the class III deacetylase SIRT1, which can regulate HR, is recruited to E1-E2-replicating DNA and regulates the level of replication. Here, we demonstrate that SIRT1 promotes the fidelity of E1-E2 replication and that the absence of SIRT1 results in reduced recruitment of the DNA repair protein Werner helicase (WRN) to E1-E2-replicating DNA. CRISPR/Cas9 editing demonstrates that WRN, like SIRT1, regulates the quantity and fidelity of E1-E2 replication. This is the first report of WRN regulation of E1-E2 DNA replication, or a role for WRN in the HPV life cycle. In the absence of SIRT1 there is an increased acetylation and stability of WRN, but a reduced ability to interact with E1-E2-replicating DNA. We present a model in which E1-E2 replication turns on the DDR, stimulating SIRT1 deacetylation of WRN. This deacetylation promotes WRN interaction with E1-E2-replicating DNA to control the quantity and fidelity of replication. As well as offering a crucial insight into HPV replication control, this system offers a unique model for investigating the link between SIRT1 and WRN in controlling replication in mammalian cells.IMPORTANCE HPV16 is the major viral human carcinogen responsible for between 3 and 4% of all cancers worldwide. Following infection, this virus activates the DNA damage response (DDR) to promote its life cycle and recruits DDR proteins to its replicating DNA in order to facilitate homologous recombination during replication. This promotes the production of viable viral progeny. Our understanding of how HPV16 replication interacts with the DDR remains incomplete. Here, we demonstrate that the cellular deacetylase SIRT1, which is a part of the E1-E2 replication complex, regulates recruitment of the DNA repair protein WRN to the replicating DNA. We demonstrate that WRN regulates the level and fidelity of E1-E2 replication. Overall, the results suggest a mechanism by which SIRT1 deacetylation of WRN promotes its interaction with E1-E2-replicating DNA to control the levels and fidelity of that replication.
Collapse
Affiliation(s)
- Dipon Das
- Department of Oral and Craniofacial Molecular Biology, VCU Philips Institute for Oral Health Research, Virginia Commonwealth University School of Dentistry, Richmond, Virginia, USA
| | - Molly L Bristol
- Department of Oral and Craniofacial Molecular Biology, VCU Philips Institute for Oral Health Research, Virginia Commonwealth University School of Dentistry, Richmond, Virginia, USA
| | - Nathan W Smith
- Department of Oral and Craniofacial Molecular Biology, VCU Philips Institute for Oral Health Research, Virginia Commonwealth University School of Dentistry, Richmond, Virginia, USA
| | - Claire D James
- Department of Oral and Craniofacial Molecular Biology, VCU Philips Institute for Oral Health Research, Virginia Commonwealth University School of Dentistry, Richmond, Virginia, USA
| | - Xu Wang
- Department of Oral and Craniofacial Molecular Biology, VCU Philips Institute for Oral Health Research, Virginia Commonwealth University School of Dentistry, Richmond, Virginia, USA
| | - Pietro Pichierri
- Department of Environment and Health, Istituto Superiore di Sanità, Rome, Italy
| | - Iain M Morgan
- Department of Oral and Craniofacial Molecular Biology, VCU Philips Institute for Oral Health Research, Virginia Commonwealth University School of Dentistry, Richmond, Virginia, USA
- VCU Massey Cancer Center, Richmond, Virginia, USA
| |
Collapse
|
8
|
Kim JH, Grosbart M, Anand R, Wyman C, Cejka P, Petrini JHJ. The Mre11-Nbs1 Interface Is Essential for Viability and Tumor Suppression. Cell Rep 2017; 18:496-507. [PMID: 28076792 DOI: 10.1016/j.celrep.2016.12.035] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2016] [Revised: 11/04/2016] [Accepted: 12/12/2016] [Indexed: 02/02/2023] Open
Abstract
The Mre11 complex (Mre11, Rad50, and Nbs1) is integral to both DNA repair and ataxia telangiectasia mutated (ATM)-dependent DNA damage signaling. All three Mre11 complex components are essential for viability at the cellular and organismal levels. To delineate essential and non-essential Mre11 complex functions that are mediated by Nbs1, we used TALEN-based genome editing to derive Nbs1 mutant mice (Nbs1mid mice), which harbor mutations in the Mre11 interaction domain of Nbs1. Nbs1mid alleles that abolished interaction were incompatible with viability. Conversely, a 108-amino-acid Nbs1 fragment comprising the Mre11 interface was sufficient to rescue viability and ATM activation in cultured cells and support differentiation of hematopoietic cells in vivo. These data indicate that the essential role of Nbs1 is via its interaction with Mre11 and that most of the Nbs1 protein is dispensable for Mre11 complex functions and suggest that Mre11 and Rad50 directly activate ATM.
Collapse
Affiliation(s)
- Jun Hyun Kim
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10021, USA
| | - Malgorzata Grosbart
- Department of Molecular Genetics, Erasmus University Medical Center, 3000 Rotterdam, the Netherlands; Department of Radiation Oncology, Erasmus University Medical Center, 3000 Rotterdam, the Netherlands
| | - Roopesh Anand
- Institute for Research in Biomedicine, Università della Svizzera Italiana, Via Vincenzo Vela 6, 6500 Bellinzona, Switzerland
| | - Claire Wyman
- Department of Molecular Genetics, Erasmus University Medical Center, 3000 Rotterdam, the Netherlands; Department of Radiation Oncology, Erasmus University Medical Center, 3000 Rotterdam, the Netherlands
| | - Petr Cejka
- Institute for Research in Biomedicine, Università della Svizzera Italiana, Via Vincenzo Vela 6, 6500 Bellinzona, Switzerland
| | - John H J Petrini
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10021, USA.
| |
Collapse
|
9
|
Liu Y, Cussiol JR, Dibitetto D, Sims JR, Twayana S, Weiss RS, Freire R, Marini F, Pellicioli A, Smolka MB. TOPBP1 Dpb11 plays a conserved role in homologous recombination DNA repair through the coordinated recruitment of 53BP1 Rad9. J Cell Biol 2017; 216:623-639. [PMID: 28228534 PMCID: PMC5350513 DOI: 10.1083/jcb.201607031] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 11/30/2016] [Accepted: 01/09/2017] [Indexed: 01/24/2023] Open
Abstract
The scaffold protein TOPBP1Dpb11 has been implicated in homologous recombination DNA repair, but its function and mechanism of action remain unclear. Liu et al. define a conserved role for TOPBP1Dpb11 in recombination control through regulated, opposing interactions with pro- and anti-resection factors. Genome maintenance and cancer suppression require homologous recombination (HR) DNA repair. In yeast and mammals, the scaffold protein TOPBP1Dpb11 has been implicated in HR, although its precise function and mechanism of action remain elusive. In this study, we show that yeast Dpb11 plays an antagonistic role in recombination control through regulated protein interactions. Dpb11 mediates opposing roles in DNA end resection by coordinating both the stabilization and exclusion of Rad9 from DNA lesions. The Mec1 kinase promotes the pro-resection function of Dpb11 by mediating its interaction with the Slx4 scaffold. Human TOPBP1Dpb11 engages in interactions with the anti-resection factor 53BP1 and the pro-resection factor BRCA1, suggesting that TOPBP1 also mediates opposing functions in HR control. Hyperstabilization of the 53BP1–TOPBP1 interaction enhances the recruitment of 53BP1 to nuclear foci in the S phase, resulting in impaired HR and the accumulation of chromosomal aberrations. Our results support a model in which TOPBP1Dpb11 plays a conserved role in mediating a phosphoregulated circuitry for the control of recombinational DNA repair.
Collapse
Affiliation(s)
- Yi Liu
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853
| | - José Renato Cussiol
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853
| | - Diego Dibitetto
- Department of Biosciences, University of Milan, 20133 Milan, Italy
| | - Jennie Rae Sims
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853
| | - Shyam Twayana
- Department of Biosciences, University of Milan, 20133 Milan, Italy
| | | | - Raimundo Freire
- Unidad de Investigación, Hospital Universitario de Canarias, Instituto de Tecnologias Biomedicas, 38320 Tenerife, Spain
| | - Federica Marini
- Department of Biosciences, University of Milan, 20133 Milan, Italy
| | | | - Marcus Bustamante Smolka
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853
| |
Collapse
|
10
|
Choi SH, Yoo HY. Mdc1 modulates the interaction between TopBP1 and the MRN complex during DNA damage checkpoint responses. Biochem Biophys Res Commun 2016; 479:5-11. [PMID: 27590578 DOI: 10.1016/j.bbrc.2016.08.158] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 08/27/2016] [Indexed: 10/21/2022]
Abstract
TopBP1 has been identified as a direct activator of ATR and interacts with the Nbs1 subunit of the Mre11-Rad50-Nbs1 (MRN) complex in egg extracts in a checkpoint-regulated manner. In this study, we show that Mdc1 associates with both TopBP1 and Nbs1 in egg extracts and human cells. We cloned a cDNA encoding the full-length version of Xenopus Mdc1. The association between Mdc1 and TopBP1 involves the first pair of BRCT repeats in TopBP1. The N-terminal region (161-230) of Mdc1 is required for this binding. The interaction between Mdc1 and Nbs1 involves the two tandem BRCT repeats of Nbs1. Functional studies with mutated forms of Mdc1, TopBP1, and Nbs1 indicate that the BRCT-dependent association of these proteins is critical for a normal checkpoint response to DSBs. TopBP1 cannot interact with Nbs1 in Mdc1-depleted egg extracts, suggesting that Mdc1 connects TopBP1 and Nbs1 together. These findings suggest that Mdc1 is a crucial mediator of the DNA damage checkpoint response.
Collapse
Affiliation(s)
- Seung Ho Choi
- Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology, Sungkyunkwan University, Seoul 135-710, Republic of Korea; Samsung Biomedical Research Institute, Research Institute for Future Medicine, Samsung Medical Center, Seoul 135-710, Republic of Korea
| | - Hae Yong Yoo
- Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology, Sungkyunkwan University, Seoul 135-710, Republic of Korea; Samsung Biomedical Research Institute, Research Institute for Future Medicine, Samsung Medical Center, Seoul 135-710, Republic of Korea.
| |
Collapse
|
11
|
Komatsu K. NBS1 and multiple regulations of DNA damage response. JOURNAL OF RADIATION RESEARCH 2016; 57 Suppl 1:i11-i17. [PMID: 27068998 PMCID: PMC4990113 DOI: 10.1093/jrr/rrw031] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 02/09/2016] [Accepted: 02/13/2016] [Indexed: 05/19/2023]
Abstract
DNA damage response is finely tuned, with several pathways including those for DNA repair, chromatin remodeling and cell cycle checkpoint, although most studies to date have focused on single pathways. Genetic diseases characterized by genome instability have provided novel insights into the underlying mechanisms of DNA damage response. NBS1, a protein responsible for the radiation-sensitive autosomal recessive disorder Nijmegen breakage syndrome, is one of the first factors to accumulate at sites of DNA double-strand breaks (DSBs). NBS1 binds to at least five key proteins, including ATM, RPA, MRE11, RAD18 and RNF20, in the conserved regions within a limited span of the C terminus, functioning in the regulation of chromatin remodeling, cell cycle checkpoint and DNA repair in response to DSBs. In this article, we reviewed the functions of these binding proteins and their comprehensive association with NBS1.
Collapse
Affiliation(s)
- Kenshi Komatsu
- Division of Genome Repair Dynamics, Radiation Biology Center, Kyoto University, Yoshida-Konoecho, Sakyo-Ku, Kyoto 606-8501, Japan
| |
Collapse
|
12
|
Moudry P, Watanabe K, Wolanin KM, Bartkova J, Wassing IE, Watanabe S, Strauss R, Troelsgaard Pedersen R, Oestergaard VH, Lisby M, Andújar-Sánchez M, Maya-Mendoza A, Esashi F, Lukas J, Bartek J. TOPBP1 regulates RAD51 phosphorylation and chromatin loading and determines PARP inhibitor sensitivity. J Cell Biol 2016; 212:281-8. [PMID: 26811421 PMCID: PMC4748576 DOI: 10.1083/jcb.201507042] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 01/03/2016] [Indexed: 01/01/2023] Open
Abstract
Topoisomerase IIβ-binding protein 1 (TOPBP1) participates in DNA replication and DNA damage response; however, its role in DNA repair and relevance for human cancer remain unclear. Here, through an unbiased small interfering RNA screen, we identified and validated TOPBP1 as a novel determinant whose loss sensitized human cells to olaparib, an inhibitor of poly(ADP-ribose) polymerase. We show that TOPBP1 acts in homologous recombination (HR) repair, impacts olaparib response, and exhibits aberrant patterns in subsets of human ovarian carcinomas. TOPBP1 depletion abrogated RAD51 loading to chromatin and formation of RAD51 foci, but without affecting the upstream HR steps of DNA end resection and RPA loading. Furthermore, TOPBP1 BRCT domains 7/8 are essential for RAD51 foci formation. Mechanistically, TOPBP1 physically binds PLK1 and promotes PLK1 kinase-mediated phosphorylation of RAD51 at serine 14, a modification required for RAD51 recruitment to chromatin. Overall, our results provide mechanistic insights into TOPBP1's role in HR, with potential clinical implications for cancer treatment.
Collapse
Affiliation(s)
- Pavel Moudry
- Danish Cancer Society Research Center, DK-2100 Copenhagen, Denmark Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacky University, 779 00 Olomouc, Czech Republic
| | - Kenji Watanabe
- Danish Cancer Society Research Center, DK-2100 Copenhagen, Denmark
| | - Kamila M Wolanin
- Danish Cancer Society Research Center, DK-2100 Copenhagen, Denmark
| | - Jirina Bartkova
- Danish Cancer Society Research Center, DK-2100 Copenhagen, Denmark Department of Medical Biochemistry and Biophysics, Science For Life Laboratory, Division of Translational Medicine and Chemical Biology, Karolinska Institute, 17121 Solna, Sweden
| | - Isabel E Wassing
- The Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, England, UK
| | - Sugiko Watanabe
- Danish Cancer Society Research Center, DK-2100 Copenhagen, Denmark
| | - Robert Strauss
- Danish Cancer Society Research Center, DK-2100 Copenhagen, Denmark
| | | | - Vibe H Oestergaard
- Department of Biology, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Michael Lisby
- Department of Biology, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Miguel Andújar-Sánchez
- Department of Pathology, Familial and Hereditary Cancer Unit, University Hospital, 35010 Las Palmas de Gran Canaria, Spain
| | | | - Fumiko Esashi
- The Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, England, UK
| | - Jiri Lukas
- Danish Cancer Society Research Center, DK-2100 Copenhagen, Denmark Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Jiri Bartek
- Danish Cancer Society Research Center, DK-2100 Copenhagen, Denmark Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacky University, 779 00 Olomouc, Czech Republic Department of Medical Biochemistry and Biophysics, Science For Life Laboratory, Division of Translational Medicine and Chemical Biology, Karolinska Institute, 17121 Solna, Sweden
| |
Collapse
|
13
|
Liu Y, Smolka MB. TOPBP1 takes RADical command in recombinational DNA repair. J Cell Biol 2016; 212:263-6. [PMID: 26811424 PMCID: PMC4748579 DOI: 10.1083/jcb.201601028] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 01/08/2016] [Indexed: 12/15/2022] Open
Abstract
TOPBP1 is a key player in DNA replication and DNA damage signaling. In this issue, Moudry et al. (2016. J. Cell Biol.http://dx.doi.org/10.1083/jcb.201507042) uncover a crucial role for TOPBP1 in DNA repair by revealing its requirement for RAD51 loading during repair of double strand breaks by homologous recombination.
Collapse
Affiliation(s)
- Yi Liu
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853
| | - Marcus B Smolka
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853
| |
Collapse
|
14
|
Han SH, Hahm SH, Tran AHV, Chung JH, Hong MK, Paik HD, Kim KS, Han YS. A physical association between the human mutY homolog (hMYH) and DNA topoisomerase II-binding protein 1 (hTopBP1) regulates Chk1-induced cell cycle arrest in HEK293 cells. Cell Biosci 2015; 5:50. [PMID: 26312135 PMCID: PMC4550056 DOI: 10.1186/s13578-015-0042-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Accepted: 08/12/2015] [Indexed: 12/02/2022] Open
Abstract
Background Human DNA topoisomerase II-binding protein 1 (hTopBP1) plays an important role in DNA replication and the DNA damage checkpoint pathway. The human mutY homolog (hMYH) is a base excision repair DNA glycosylase that excises adenines or 2-hydroxyadenines that are mispaired with guanine or 7,8-dihydro-8-oxoguanine (8-oxoG). hTopBP1 and hMYH were involved in ATR-mediated Chk1 activation, moreover, both of them were associated with ATR and hRad9 which known as checkpoint-involved proteins. Therefore, we investigated whether hTopBP1 interacted with hMYH, and what the function of their interaction is. Results We documented the interaction between hTopBP1 and hMYH and showed that this interaction increased in a hydroxyurea-dependent manner. We also mapped the hMYH-interacting region of hTopBP1 (residues 444–991). In addition, we investigated several cell cycle-related proteins and found that co-knockdown of hTopBP1 and hMYH significantly diminished cell cycle arrest due to compromised checkpoint kinase 1 (Chk1) activation. Moreover, we observed that hMYH was essential for the accumulation of hTopBP1 on damaged DNA, where hTopBP1 interacts with hRad9, a component of the Rad9-Hus1-Rad1 complex. The accumulation of hTopBP1 on chromatin and its subsequent interaction with hRad9 lead to cell cycle arrest, a process mediated by Chk1 phosphorylation and ataxia telangiectasia and Rad3-related protein (ATR) activation. Conclusions Our results suggested that hMYH is necessary for the accumulation of hTopBP1 to DNA damage lesion to induce the association of hTopBP1 with 9-1-1 and that the interaction between hMYH and hTopBP1 is essential for Chk1 activation. Therefore, we suggest that the interaction between hMYH and hTopBP1 is crucial for activation of the ATR-mediated cell cycle checkpoint. Electronic supplementary material The online version of this article (doi:10.1186/s13578-015-0042-x) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Se Hee Han
- Department of Advanced Technology Fusion, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, 143-701 Republic of Korea
| | - Soo-Hyun Hahm
- Department of Advanced Technology Fusion, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, 143-701 Republic of Korea
| | - An Hue Vy Tran
- Department of Advanced Technology Fusion, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, 143-701 Republic of Korea
| | - Ji Hyung Chung
- Department of Applied Bioscience, College of Life Science, CHA University, 120 Haeryong-ro, Pocheon, Gyeonggi-do 463-836 Republic of Korea
| | - Myoung-Ki Hong
- Department of Biological Sciences, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, 143-701 Republic of Korea
| | - Hyun-Dong Paik
- Department of Food Science and Biotechnology of Animal Resources, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, 143-701 Republic of Korea
| | - Key-Sun Kim
- Center for Neuroscience, Korea Institute of Science and Technology, 5 Hwarang-ro 14-gil, Seongbuk-gu, Seoul, Republic of Korea
| | - Ye Sun Han
- Department of Advanced Technology Fusion, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, 143-701 Republic of Korea ; College of Global Integrated Studies, Division of Interdisciplinary Studies, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, 143-701 Republic of Korea
| |
Collapse
|
15
|
Evidence supporting a role for TopBP1 and Brd4 in the initiation but not continuation of human papillomavirus 16 E1/E2-mediated DNA replication. J Virol 2015; 89:4980-91. [PMID: 25694599 DOI: 10.1128/jvi.00335-15] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 02/12/2015] [Indexed: 12/17/2022] Open
Abstract
UNLABELLED To replicate the double-stranded human papillomavirus 16 (HPV16) DNA genome, viral proteins E1 and E2 associate with the viral origin of replication, and E2 can also regulate transcription from adjacent promoters. E2 interacts with host proteins in order to regulate both transcription and replication; TopBP1 and Brd4 are cellular proteins that interact with HPV16 E2. Previous work with E2 mutants demonstrated the Brd4 requirement for the transactivation properties of E2, while TopBP1 is required for DNA replication induced by E2 from the viral origin of replication in association with E1. More-recent studies have also implicated Brd4 in the regulation of DNA replication by E2 and E1. Here, we demonstrate that both TopBP1 and Brd4 are present at the viral origin of replication and that interaction with E2 is required for optimal initiation of DNA replication. Both cellular proteins are present in E1-E2-containing nuclear foci, and the viral origin of replication is required for the efficient formation of these foci. Short hairpin RNA (shRNA) against either TopBP1 or Brd4 destroys the E1-E2 nuclear bodies but has no effect on E1-E2-mediated levels of DNA replication. An E2 mutation in the context of the complete HPV16 genome that compromises Brd4 interaction fails to efficiently establish episomes in primary human keratinocytes. Overall, the results suggest that interactions between TopBP1 and E2 and between Brd4 and E2 are required to correctly initiate DNA replication but are not required for continuing DNA replication, which may be mediated by alternative processes such as rolling circle amplification and/or homologous recombination. IMPORTANCE Human papillomavirus 16 (HPV16) is causative in many human cancers, including cervical and head and neck cancers, and is responsible for the annual deaths of hundreds of thousands of people worldwide. The current vaccine will save lives in future generations, but antivirals targeting HPV16 are required for the alleviation of disease burden on the current, and future, generations. Targeting viral DNA replication that is mediated by two viral proteins, E1 and E2, in association with cellular proteins such as TopBP1 and Brd4 would have therapeutic benefits. This report suggests a role for these cellular proteins in the initiation of viral DNA replication by HPV16 E1-E2 but not for continuing replication. This is important if viral replication is to be effectively targeted; we need to understand the viral and cellular proteins required at each phase of viral DNA replication so that it can be effectively disrupted.
Collapse
|
16
|
Saito Y, Zhou H, Kobayashi J. Chromatin modification and NBS1: their relationship in DNA double-strand break repair. Genes Genet Syst 2015; 90:195-208. [DOI: 10.1266/ggs.15-00010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Affiliation(s)
- Yuichiro Saito
- Department of Genome Repair Dynamics, Radiation Biology Center, Kyoto University
| | - Hui Zhou
- Department of Genome Repair Dynamics, Radiation Biology Center, Kyoto University
| | - Junya Kobayashi
- Department of Genome Repair Dynamics, Radiation Biology Center, Kyoto University
| |
Collapse
|
17
|
Wardlaw CP, Carr AM, Oliver AW. TopBP1: A BRCT-scaffold protein functioning in multiple cellular pathways. DNA Repair (Amst) 2014; 22:165-74. [PMID: 25087188 DOI: 10.1016/j.dnarep.2014.06.004] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 06/11/2014] [Indexed: 11/25/2022]
Abstract
Human TopBP1 contains nine BRCT domains and functions in DNA replication initiation, checkpoint signalling, DNA repair and influences transcriptional control. TopBP1 and its homologues have been the subject of numerous scientific publications since the last comprehensive review in 2005, emerging as a key scaffold protein that links crucial components within these distinct cellular processes. This review focuses on recently published work, with particular emphasis on structural insights into TopBP1 function and the binding partners identified for DNA replication initiation, DNA-dependent checkpoints, DNA repair and transcription. We further summarise what is known about TopBP1 and links to human disease.
Collapse
Affiliation(s)
- Christopher P Wardlaw
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer BN1 9RQ, UK.
| | - Antony M Carr
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer BN1 9RQ, UK
| | - Antony W Oliver
- Cancer Research UK DNA Repair Enzymes Group, Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer BN1 9RQ, UK
| |
Collapse
|
18
|
Gatei M, Kijas AW, Biard D, Dörk T, Lavin MF. RAD50 phosphorylation promotes ATR downstream signaling and DNA restart following replication stress. Hum Mol Genet 2014; 23:4232-48. [PMID: 24694934 DOI: 10.1093/hmg/ddu141] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The MRE11/RAD50/NBN (MRN) complex plays a key role in detecting DNA double-strand breaks, recruiting and activating ataxia-telangiectasia mutated and in processing the breaks. Members of this complex also act as adaptor molecules for downstream signaling to the cell cycle and other cellular processes. Somewhat more controversial are the results to support a role for MRN in the ataxia-telangiectasia and Rad3-related (ATR) activation and signaling. We provide evidence that RAD50 is required for ATR activation in mammalian cells in response to DNA replication stress. It is in turn phosphorylated at a specific site (S635) by ATR, which is required for ATR signaling through Chk1 and other downstream substrates. We find that RAD50 phosphorylation is essential for DNA replication restart by promoting loading of cohesin at these sites. We also demonstrate that replication stress-induced RAD50 phosphorylation is functionally significant for cell survival and cell cycle checkpoint activation. These results highlight the importance of the adaptor role for a member of the MRN complex in all aspects of the response to DNA replication stress.
Collapse
Affiliation(s)
- Magtouf Gatei
- Radiation Biology and Oncology, QIMR Berghofer Medical Research Institute, Brisbane, QLD 4029, Australia
| | - Amanda W Kijas
- Radiation Biology and Oncology, QIMR Berghofer Medical Research Institute, Brisbane, QLD 4029, Australia
| | - Denis Biard
- CEA, DSV/iMETI/SEPIA; BP6, 92265 Fontenay-aux-Roses Cedex, France
| | - Thilo Dörk
- Clinics of Obstetrics and Gynaecology, Hannover Medical School, Gynaecology Research Unit, Carl-Neuberg-Str. 1, D-30625 Hannover, Germany and
| | - Martin F Lavin
- Radiation Biology and Oncology, QIMR Berghofer Medical Research Institute, Brisbane, QLD 4029, Australia Centre for Clinical Research, University of Queensland, Building 71/918, Royal Brisbane & Women's Hospital Campus, Herston, QLD 4029, Australia
| |
Collapse
|
19
|
Kim J, Lee SK, Jeon Y, Kim Y, Lee C, Jeon SH, Shim J, Kim IH, Hong S, Kim N, Lee H, Seong RH. TopBP1 deficiency impairs V(D)J recombination during lymphocyte development. EMBO J 2014; 33:217-28. [PMID: 24442639 DOI: 10.1002/embj.201284316] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
TopBP1 was initially identified as a topoisomerase II-β-binding protein and it plays roles in DNA replication and repair. We found that TopBP1 is expressed at high levels in lymphoid tissues and is essential for early lymphocyte development. Specific abrogation of TopBP1 expression resulted in transitional blocks during early lymphocyte development. These defects were, in major part, due to aberrant V(D)J rearrangements in pro-B cells, double-negative and double-positive thymocytes. We also show that TopBP1 was located at sites of V(D)J rearrangement. In TopBP1-deficient cells, γ-H2AX foci were found to be increased. In addition, greater amount of γ-H2AX product was precipitated from the regions where TopBP1 was localized than from controls, indicating that TopBP1 deficiency results in inefficient DNA double-strand break repair. The developmental defects were rescued by introducing functional TCR αβ transgenes. Our data demonstrate a novel role for TopBP1 as a crucial factor in V(D)J rearrangement during the development of B, T and iNKT cells.
Collapse
Affiliation(s)
- Jieun Kim
- Department of Biological Sciences, Institute of Molecular Biology and Genetics Research Center for Functional Cellulomics Seoul National University, Seoul, Korea
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Duursma AM, Driscoll R, Elias JE, Cimprich KA. A role for the MRN complex in ATR activation via TOPBP1 recruitment. Mol Cell 2013; 50:116-22. [PMID: 23582259 DOI: 10.1016/j.molcel.2013.03.006] [Citation(s) in RCA: 113] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Revised: 02/11/2013] [Accepted: 03/05/2013] [Indexed: 12/17/2022]
Abstract
The MRN (MRE11-RAD50-NBS1) complex has been implicated in many aspects of the DNA damage response. It has key roles in sensing and processing DNA double-strand breaks, as well as in activation of ATM (ataxia telangiectasia mutated). We reveal a function for MRN in ATR (ATM- and RAD3-related) activation by using defined ATR-activating DNA structures in Xenopus egg extracts. Strikingly, we demonstrate that MRN is required for recruitment of TOPBP1 to an ATR-activating structure that contains a single-stranded DNA (ssDNA) and a double-stranded DNA (dsDNA) junction and that this recruitment is necessary for phosphorylation of CHK1. We also show that the 911 (RAD9-RAD1-HUS1) complex is not required for TOPBP1 recruitment but is essential for TOPBP1 function. Thus, whereas MRN is required for TOPBP1 recruitment at an ssDNA-to-dsDNA junction, 911 is required for TOPBP1 "activation." These findings provide molecular insights into how ATR is activated.
Collapse
Affiliation(s)
- Anja M Duursma
- Department of Chemical and Systems Biology, Stanford University, Stanford, CA 94305, USA
| | | | | | | |
Collapse
|
21
|
Kobayashi M, Hayashi N, Takata M, Yamamoto KI. NBS1 directly activates ATR independently of MRE11 and TOPBP1. Genes Cells 2013; 18:238-46. [PMID: 23368512 DOI: 10.1111/gtc.12031] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2012] [Accepted: 12/07/2012] [Indexed: 11/29/2022]
Abstract
NBS1 plays unique and essential roles in ATM activation in response to DNA double-strand breaks. We found that CHK1 phosphorylation and FANCD2 ubiquitination induced by various DNA replication-stalling agents were abrogated in Nbs1 knockout DT40 cells but not in conditional Mre11 knockout cells, indicating an MRE11-independent role for NBS1 in ATR activation. The results of in vitro ATR kinase assay indicated that the N-terminal region of NBS1 directly activates ATR independently of TOPBP1, consistent with the findings that this region of NBS1 directly interacts with ATR. This conclusion was furthermore supported by the results of in vivo experiments; the expression of the N-terminal region of NBS1 fused to PCNA induces ATR activation in Rad17 knockout cells, and the expression of the ATR activation domain of TOPBP1 fused to PCNA induces ATR activation in Nbs1 knockout cells. These results therefore indicate that NBS1 and TOPBP1 have the potential to activate ATR independently, although both are required for functional activation of ATR in vivo.
Collapse
Affiliation(s)
- Masahiko Kobayashi
- Department of Molecular Pathology, Cancer Research Institute, Kanazawa University, Kanazawa, Ishikawa, 920-1192, Japan.
| | | | | | | |
Collapse
|
22
|
CBP and p300 histone acetyltransferases contribute to homologous recombination by transcriptionally activating the BRCA1 and RAD51 genes. PLoS One 2012; 7:e52810. [PMID: 23285190 PMCID: PMC3527616 DOI: 10.1371/journal.pone.0052810] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2012] [Accepted: 11/21/2012] [Indexed: 12/05/2022] Open
Abstract
Histone acetylation at DNA double-strand break (DSB) sites by CBP and p300 histone acetyltransferases (HATs) is critical for the recruitment of DSB repair proteins to chromatin. Here, we show that CBP and p300 HATs also function in DSB repair by transcriptionally activating the BRCA1 and RAD51 genes, which are involved in homologous recombination (HR), a major DSB repair system. siRNA-mediated depletion of CBP and p300 impaired HR activity and downregulated BRCA1 and RAD51 at the protein and mRNA levels. Chromatin immunoprecipitation assays showed that CBP and p300 bind to the promoter regions of the BRCA1 and RAD51 genes, and that depletion of CBP and/or p300 reduces H3 and H4 acetylation and inhibits binding of the transcription factor E2F1 to these promoters. Depletion of CBP and p300 impaired DNA damage-induced phosphorylation and chromatin binding of the single-strand DNA-binding protein RPA following BRCA1-mediated DNA end resection. Consistent with this, subsequent phosphorylation of CHK1 and activation of the G2/M damage checkpoint were also impaired. These results indicate that the HATs CBP and p300 play multiple roles in the activation of the cellular response to DSBs.
Collapse
|
23
|
Abstract
The breast cancer type 1 susceptibility protein (BRCA1) is involved in several important cellular pathways, including DNA damage repair, chromatin remodeling and checkpoint activation. The BRCA1 tumor suppression function has been attributed to its role in homologous recombination damage repair. In this review, historical facts concerning BRCA1, together with recent research advances regarding our understanding of the BRCA1 interacting proteins that are involved in, homologous recombination (HR) double strand break (DBS) repair and how these interacting proteins maintain chromosomal integrity, are discussed. In addition, this review poses the questions as to what extent HR repair cannot be properly fulfilled when breast cancer related mutations in the BRCA1 gene occur and how the recent and excessive studied poly-ADP ribose polymerase (PARP) inhibiting therapy approach links with the proposed tumor suppression function of the different BRCA1 domains.
Collapse
Affiliation(s)
- Kevin W Caestecker
- Department of Comparative Physiology and Biometrics, Faculty of Veterinary Medicine, Ghent University, B-9820 Merelbeke, Belgium
| | | |
Collapse
|
24
|
An interaction between human papillomavirus 16 E2 and TopBP1 is required for optimum viral DNA replication and episomal genome establishment. J Virol 2012; 86:12806-15. [PMID: 22973044 DOI: 10.1128/jvi.01002-12] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
In human papillomavirus DNA replication, the viral protein E2 forms homodimers and binds to 12-bp palindromic DNA sequences surrounding the origin of DNA replication. Via a protein-protein interaction, it then recruits the viral helicase E1 to an A/T-rich origin of replication, whereupon a dihexamer forms, resulting in DNA replication initiation. In order to carry out DNA replication, the viral proteins must interact with host factors that are currently not all known. An attractive cellular candidate for regulating viral replication is TopBP1, a known interactor of the E2 protein. In mammalian DNA replication, TopBP1 loads DNA polymerases onto the replicative helicase after the G(1)-to-S transition, and this process is tightly cell cycle controlled. The direct interaction between E2 and TopBP1 would allow E2 to bypass this cell cycle control, resulting in DNA replication more than once per cell cycle, which is a requirement for the viral life cycle. We report here the generation of an HPV16 E2 mutant compromised in TopBP1 interaction in vivo and demonstrate that this mutant retains transcriptional activation and repression functions but has suboptimal DNA replication potential. Introduction of this mutant into a viral life cycle model results in the failure to establish viral episomes. The results present a potential new antiviral target, the E2-TopBP1 interaction, and increase our understanding of the viral life cycle, suggesting that the E2-TopBP1 interaction is essential.
Collapse
|
25
|
Forma E, Krzeslak A, Bernaciak M, Romanowicz-Makowska H, Brys M. Expression of TopBP1 in hereditary breast cancer. Mol Biol Rep 2012; 39:7795-804. [PMID: 22544570 PMCID: PMC3358587 DOI: 10.1007/s11033-012-1622-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Accepted: 04/16/2012] [Indexed: 01/27/2023]
Abstract
TopBP1 protein displays structural as well as functional similarities to BRCA1 and is involved in DNA replication, DNA damage checkpoint response and transcriptional regulation. Aberrant expression of TopBP1 may lead to genomic instability and can have pathological consequences. In this study we aimed to investigate expression of TopBP1 gene at mRNA and protein level in hereditary breast cancer. Real-time quantitative PCR was performed in 127 breast cancer samples. Expression of TopBP1 mRNA in lobular carcinoma was significantly lower compared with ductal carcinoma (p < 0.05). The level of TopBP1 mRNA appeared to be lower in poorly differentiated (III grade) hereditary breast cancer in comparison with moderately (II grade) and well-differentiated cancer (I grade) (p < 0.05 and p < 0.001 respectively). We analyzed TopBP1 protein expression using immunohistochemistry and Western blot techniques. Expression of TopBP1 protein was found to be significantly increased in poorly differentiated breast cancer (III grade) (p < 0.05). The percentage of samples with cytoplasmic apart from nuclear staining increased with increasing histological grade. There was no significant association between level and intracellular localization of TopBP1 protein in hereditary breast cancer and other clinicopathological parameters such as estrogen and progesterone receptors status, appearance of metastasis in the axillary lymph nodes and type of cancer. Our data suggest that decreased level of TopBP1 mRNA and increased level of TopBP1 protein might be associated with progression of hereditary breast cancer.
Collapse
Affiliation(s)
- Ewa Forma
- Department of Cytobiochemistry, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland.
| | | | | | | | | |
Collapse
|
26
|
Thompson LH. Recognition, signaling, and repair of DNA double-strand breaks produced by ionizing radiation in mammalian cells: the molecular choreography. Mutat Res 2012; 751:158-246. [PMID: 22743550 DOI: 10.1016/j.mrrev.2012.06.002] [Citation(s) in RCA: 261] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Revised: 06/09/2012] [Accepted: 06/16/2012] [Indexed: 12/15/2022]
Abstract
The faithful maintenance of chromosome continuity in human cells during DNA replication and repair is critical for preventing the conversion of normal diploid cells to an oncogenic state. The evolution of higher eukaryotic cells endowed them with a large genetic investment in the molecular machinery that ensures chromosome stability. In mammalian and other vertebrate cells, the elimination of double-strand breaks with minimal nucleotide sequence change involves the spatiotemporal orchestration of a seemingly endless number of proteins ranging in their action from the nucleotide level to nucleosome organization and chromosome architecture. DNA DSBs trigger a myriad of post-translational modifications that alter catalytic activities and the specificity of protein interactions: phosphorylation, acetylation, methylation, ubiquitylation, and SUMOylation, followed by the reversal of these changes as repair is completed. "Superfluous" protein recruitment to damage sites, functional redundancy, and alternative pathways ensure that DSB repair is extremely efficient, both quantitatively and qualitatively. This review strives to integrate the information about the molecular mechanisms of DSB repair that has emerged over the last two decades with a focus on DSBs produced by the prototype agent ionizing radiation (IR). The exponential growth of molecular studies, heavily driven by RNA knockdown technology, now reveals an outline of how many key protein players in genome stability and cancer biology perform their interwoven tasks, e.g. ATM, ATR, DNA-PK, Chk1, Chk2, PARP1/2/3, 53BP1, BRCA1, BRCA2, BLM, RAD51, and the MRE11-RAD50-NBS1 complex. Thus, the nature of the intricate coordination of repair processes with cell cycle progression is becoming apparent. This review also links molecular abnormalities to cellular pathology as much a possible and provides a framework of temporal relationships.
Collapse
Affiliation(s)
- Larry H Thompson
- Biology & Biotechnology Division, L452, Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, CA 94551-0808, United States.
| |
Collapse
|
27
|
Kumar S, Yoo HY, Kumagai A, Shevchenko A, Shevchenko A, Dunphy WG. Role for Rif1 in the checkpoint response to damaged DNA in Xenopus egg extracts. Cell Cycle 2012; 11:1183-94. [PMID: 22391207 DOI: 10.4161/cc.11.6.19636] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
TopBP1 is critical for both DNA replication and checkpoint regulation in vertebrate cells. In this study, we have identified Rif1 as a binding partner of TopBP1 in Xenopus egg extracts. In addition, Rif1 also interacts with both ATM and the Mre11-Rad50-Nbs1 (MRN) complex, which are key regulators of checkpoint responses to double-stranded DNA breaks (DSBs). Depletion of Rif1 from egg extracts compromises the activation of Chk1 in response to DSBs but not stalled replication forks. Removal of Rif1 also has a significant impact on the chromatin-binding behavior of key checkpoint proteins. In particular, binding of TopBP1, ATR and the MRN complex to chromatin containing DSBs is reduced in the absence of Rif1. Rif1 interacts with chromatin in a highly regulated and dynamic manner. In unperturbed egg extracts, the association of Rif1 with chromatin depends upon formation of replication forks. In the presence of DSBs, there is elevated accumulation of Rif1 on chromatin under conditions where the activation of ATM is suppressed. Taken together, these results suggest that Rif1 plays a dynamic role in the early steps of a checkpoint response to DSBs in the egg-extract system by promoting the correct accumulation of key regulators on the DNA.
Collapse
Affiliation(s)
- Sanjay Kumar
- Division of Biology 147-75, California Institute of Technology, Pasadena, CA, USA
| | | | | | | | | | | |
Collapse
|
28
|
Jeon Y, Ko E, Lee KY, Ko MJ, Park SY, Kang J, Jeon CH, Lee H, Hwang DS. TopBP1 deficiency causes an early embryonic lethality and induces cellular senescence in primary cells. J Biol Chem 2010; 286:5414-22. [PMID: 21149450 DOI: 10.1074/jbc.m110.189704] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
TopBP1 plays important roles in chromosome replication, DNA damage response, and other cellular regulatory functions in vertebrates. Although the roles of TopBP1 have been studied mostly in cancer cell lines, its physiological function remains unclear in mice and untransformed cells. We generated conditional knock-out mice in which exons 5 and 6 of the TopBP1 gene are flanked by loxP sequences. Although TopBP1-deficient embryos developed to the blastocyst stage, no homozygous mutant embryos were recovered at E8.5 or beyond, and completely resorbed embryos were frequent at E7.5, indicating that mutant embryos tend to die at the peri-implantation stage. This finding indicated that TopBP1 is essential for cell proliferation during early embryogenesis. Ablation of TopBP1 in TopBP1(flox/flox) mouse embryonic fibroblasts and 3T3 cells using Cre recombinase-expressing retrovirus arrests cell cycle progression at the G(1), S, and G(2)/M phases. The TopBP1-ablated mouse cells exhibit phosphorylation of H2AX and Chk2, indicating that the cells contain DNA breaks. The TopBP1-ablated mouse cells enter cellular senescence. Although RNA interference-mediated knockdown of TopBP1 induced cellular senescence in human primary cells, it induced apoptosis in cancer cells. Therefore, TopBP1 deficiency in untransformed mouse and human primary cells induces cellular senescence rather than apoptosis. These results indicate that TopBP1 is essential for cell proliferation and maintenance of chromosomal integrity.
Collapse
Affiliation(s)
- Yoon Jeon
- Cancer Experimental Resources Branch, National Cancer Center, Ilsandong-gu, Goyang-si, Gyeonggi-do 410-769, Korea
| | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Germann SM, Oestergaard VH, Haas C, Salis P, Motegi A, Lisby M. Dpb11/TopBP1 plays distinct roles in DNA replication, checkpoint response and homologous recombination. DNA Repair (Amst) 2010; 10:210-24. [PMID: 21130053 DOI: 10.1016/j.dnarep.2010.11.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2010] [Revised: 10/20/2010] [Accepted: 11/04/2010] [Indexed: 12/16/2022]
Abstract
DPB11/TopBP1 is an essential evolutionarily conserved gene involved in initiation of DNA replication and checkpoint signaling. Here, we show that Saccharomyces cerevisiae Dpb11 forms nuclear foci that localize to sites of DNA damage in G1, S and G2 phase, a recruitment that is conserved for its homologue TopBP1 in Gallus gallus. Damage-induced Dpb11 foci are distinct from Sld3 replication initiation foci. Further, Dpb11 foci are dependent on the checkpoint proteins Mec3 (9-1-1 complex) and Rad24, and require the C-terminal domain of Dpb11. Dpb11 foci are independent of the checkpoint kinases Mec1 and Tel1, and of the checkpoint mediator Rad9. In a site-directed mutagenesis screen, we identify a separation-of-function mutant, dpb11-PF, that is sensitive to DSB-inducing agents yet remains proficient for DNA replication and the S-phase checkpoint at the permissive temperature. The dpb11-PF mutant displays altered rates of heteroallelic and direct-repeat recombination, sensitivity to DSB-inducing drugs as well as delayed kinetics of mating-type switching with a defect in the DNA synthesis step thus implicating Dpb11 in homologous recombination. We conclude that Dpb11/TopBP1 plays distinct roles in replication, checkpoint response and recombination processes, thereby contributing to chromosomal stability.
Collapse
|
30
|
Huo YG, Bai L, Xu M, Jiang T. Crystal structure of the N-terminal region of human Topoisomerase IIβ binding protein 1. Biochem Biophys Res Commun 2010; 401:401-5. [PMID: 20858457 DOI: 10.1016/j.bbrc.2010.09.066] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2010] [Accepted: 09/15/2010] [Indexed: 11/15/2022]
Abstract
Human DNA Topoisomerase IIβ binding protein 1 (TopBP1) is a modulating protein that plays an essential role in the response to DNA damage. The N-terminal region of TopBP1, which contains predicted BRCA1-carboxy terminal (BRCT) domains 1 and 2, binds to Rad9, a component of the cell cycle checkpoint clamp Rad9-Hus1-Rad1 complex. Here, we report the crystal structure of the TopBP1N-terminal region (residues 1-290) at 2.4Å resolution. Interestingly, in addition to the predicted tandem BRCT1-2 repeats (residues 103-284), residues 7-98 form a previously unreported BRCT domain (here, BRCT0). In contrast to both BRCT1 and BRCT2, which possess the conventional phosphopeptide binding residues within a surface pocket, the corresponding pocket in BRCT0 is largely hydrophobic. Structural comparisons together with peptide binding studies indicate that the tandem BRCT1-2 domains are the binding region for phosphorylated Ser387 in Rad9.
Collapse
Affiliation(s)
- Yan-Gao Huo
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101, China
| | | | | | | |
Collapse
|
31
|
Abstract
Human DNA topoisomerase IIbeta-binding protein 1 (TopBP1) and its orthologues in other organisms are proteins consisting of multiple BRCT modules that have acquired several functions during evolution. These proteins execute their tasks by interacting with a great variety of proteins involved in nuclear processes. TopBP1 is an essential protein that has numerous roles in the maintenance of the genomic integrity. In particular, it is required for the activation of ATM and Rad3-related (ATR), a vital regulator of DNA replication and replication stress response. The orthologues from yeast to human are involved in DNA replication and DNA damage response, while only proteins from higher eukaryotes are also involved in complex regulation of transcription, which is related to cell proliferation, damage response and apoptosis. We review here the recent progress in research aimed at elucidating the multiple cellular functions of TopBP1, focusing on metazoan systems.
Collapse
|
32
|
Nakano T, Katafuchi A, Matsubara M, Terato H, Tsuboi T, Masuda T, Tatsumoto T, Pack SP, Makino K, Croteau DL, Van Houten B, Iijima K, Tauchi H, Ide H. Homologous recombination but not nucleotide excision repair plays a pivotal role in tolerance of DNA-protein cross-links in mammalian cells. J Biol Chem 2009; 284:27065-76. [PMID: 19674975 PMCID: PMC2785636 DOI: 10.1074/jbc.m109.019174] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2009] [Revised: 08/06/2009] [Indexed: 11/06/2022] Open
Abstract
DNA-protein cross-links (DPCs) are unique among DNA lesions in their unusually bulky nature. The steric hindrance imposed by cross-linked proteins (CLPs) will hamper DNA transactions, such as replication and transcription, posing an enormous threat to cells. In bacteria, DPCs with small CLPs are eliminated by nucleotide excision repair (NER), whereas oversized DPCs are processed exclusively by RecBCD-dependent homologous recombination (HR). Here we have assessed the roles of NER and HR for DPCs in mammalian cells. We show that the upper size limit of CLPs amenable to mammalian NER is relatively small (8-10 kDa) so that NER cannot participate in the repair of chromosomal DPCs in mammalian cells. Moreover, CLPs are not polyubiquitinated and hence are not subjected to proteasomal degradation prior to NER. In contrast, HR constitutes the major pathway in tolerance of DPCs as judged from cell survival and RAD51 and gamma-H2AX nuclear foci formation. Induction of DPCs results in the accumulation of DNA double strand breaks in HR-deficient but not HR-proficient cells, suggesting that fork breakage at the DPC site initiates HR and reactivates the stalled fork. DPCs activate both ATR and ATM damage response pathways, but there is a time lag between two responses. These results highlight the differential involvement of NER in the repair of DPCs in bacterial and mammalian cells and demonstrate the versatile and conserved role of HR in tolerance of DPCs among species.
Collapse
Affiliation(s)
- Toshiaki Nakano
- From the Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
| | - Atsushi Katafuchi
- From the Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
| | - Mayumi Matsubara
- From the Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
| | - Hiroaki Terato
- From the Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
| | - Tomohiro Tsuboi
- From the Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
| | - Tasuku Masuda
- From the Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
| | - Takahiro Tatsumoto
- From the Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
| | - Seung Pil Pack
- the Department of Biotechnology and Bioinformatics, Korea University, Jochiwon, Chungnam 339-700, Korea
| | - Keisuke Makino
- the Institute of Advanced Energy, Kyoto University, Gokasho, Uji 611-0011, Japan
| | - Deborah L. Croteau
- the Laboratory of Molecular Genetics, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina 27709, and
| | - Bennett Van Houten
- the Laboratory of Molecular Genetics, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina 27709, and
| | - Kenta Iijima
- the **Department of Environmental Sciences, Faculty of Science, Ibaraki University, Bunkyo 2-1-1, Mito, Ibaraki 310-8512, Japan
| | - Hiroshi Tauchi
- the **Department of Environmental Sciences, Faculty of Science, Ibaraki University, Bunkyo 2-1-1, Mito, Ibaraki 310-8512, Japan
| | - Hiroshi Ide
- From the Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
| |
Collapse
|
33
|
Yoo HY, Kumagai A, Shevchenko A, Shevchenko A, Dunphy WG. The Mre11-Rad50-Nbs1 complex mediates activation of TopBP1 by ATM. Mol Biol Cell 2009; 20:2351-60. [PMID: 19279141 DOI: 10.1091/mbc.e08-12-1190] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The activation of ATR-ATRIP in response to double-stranded DNA breaks (DSBs) depends upon ATM in human cells and Xenopus egg extracts. One important aspect of this dependency involves regulation of TopBP1 by ATM. In Xenopus egg extracts, ATM associates with TopBP1 and thereupon phosphorylates it on S1131. This phosphorylation enhances the capacity of TopBP1 to activate the ATR-ATRIP complex. We show that TopBP1 also interacts with the Mre11-Rad50-Nbs1 (MRN) complex in egg extracts in a checkpoint-regulated manner. This interaction involves the Nbs1 subunit of the complex. ATM can no longer interact with TopBP1 in Nbs1-depleted egg extracts, which suggests that the MRN complex helps to bridge ATM and TopBP1 together. The association between TopBP1 and Nbs1 involves the first pair of BRCT repeats in TopBP1. In addition, the two tandem BRCT repeats of Nbs1 are required for this binding. Functional studies with mutated forms of TopBP1 and Nbs1 suggested that the BRCT-dependent association of these proteins is critical for a normal checkpoint response to DSBs. These findings suggest that the MRN complex is a crucial mediator in the process whereby ATM promotes the TopBP1-dependent activation of ATR-ATRIP in response to DSBs.
Collapse
Affiliation(s)
- Hae Yong Yoo
- Division of Biology 147-75, California Institute of Technology, Pasadena, CA 91125, USA
| | | | | | | | | |
Collapse
|