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Ashton NW, Jaiswal N, Moreno NC, Semenova IV, D'Orlando DA, Latancia MT, McIntyre J, Woodgate R, Bezsonova I. A Novel Interaction Between RAD23A/B and Y-family DNA Polymerases. J Mol Biol 2023; 435:168353. [PMID: 37935254 PMCID: PMC10842004 DOI: 10.1016/j.jmb.2023.168353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 10/17/2023] [Accepted: 11/01/2023] [Indexed: 11/09/2023]
Abstract
The Y-family DNA polymerases - Pol ι, Pol η, Pol κ and Rev1 - are most well-known for their roles in the DNA damage tolerance pathway of translesion synthesis (TLS). They function to overcome replication barriers by bypassing DNA damage lesions that cannot be normally replicated, allowing replication forks to continue without stalling. In this work, we demonstrate a novel interaction between each Y-family polymerase and the nucleotide excision repair (NER) proteins, RAD23A and RAD23B. We initially focus on the interaction between RAD23A and Pol ι, and through a series of biochemical, cell-based, and structural assays, find that the RAD23A ubiquitin-binding domains (UBA1 and UBA2) interact with separate sites within the Pol ι catalytic domain. While this interaction involves the ubiquitin-binding cleft of UBA2, Pol ι interacts with a distinct surface on UBA1. We further find that mutating or deleting either UBA domain disrupts the RAD23A-Pol ι interaction, demonstrating that both interactions are necessary for stable binding. We also provide evidence that both RAD23 proteins interact with Pol ι in a similar manner, as well as with each of the Y-family polymerases. These results shed light on the interplay between the different functions of the RAD23 proteins and reveal novel binding partners for the Y-family TLS polymerases.
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Affiliation(s)
- Nicholas W Ashton
- Laboratory of Genomic Integrity, National Institute of Child Health and Human Development, National Institutes of Health, 9800 Medical Center Drive, Bethesda, MD 20892-3371, USA.
| | - Nancy Jaiswal
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, CT 06032, USA.
| | - Natália Cestari Moreno
- Laboratory of Genomic Integrity, National Institute of Child Health and Human Development, National Institutes of Health, 9800 Medical Center Drive, Bethesda, MD 20892-3371, USA.
| | - Irina V Semenova
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, CT 06032, USA.
| | - Dana A D'Orlando
- Laboratory of Genomic Integrity, National Institute of Child Health and Human Development, National Institutes of Health, 9800 Medical Center Drive, Bethesda, MD 20892-3371, USA.
| | - Marcela Teatin Latancia
- Laboratory of Genomic Integrity, National Institute of Child Health and Human Development, National Institutes of Health, 9800 Medical Center Drive, Bethesda, MD 20892-3371, USA.
| | - Justyna McIntyre
- Laboratory of Genomic Integrity, National Institute of Child Health and Human Development, National Institutes of Health, 9800 Medical Center Drive, Bethesda, MD 20892-3371, USA.
| | - Roger Woodgate
- Laboratory of Genomic Integrity, National Institute of Child Health and Human Development, National Institutes of Health, 9800 Medical Center Drive, Bethesda, MD 20892-3371, USA.
| | - Irina Bezsonova
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, CT 06032, USA.
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2
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Chen X, Walters KJ. 1H, 15N, 13C resonance assignments for proteasome shuttle factor hHR23a. Biomol NMR Assign 2023; 17:287-291. [PMID: 37812322 DOI: 10.1007/s12104-023-10157-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 10/04/2023] [Indexed: 10/10/2023]
Abstract
hHR23a (human homolog of Rad23 a) functions in nucleotide excision repair and proteasome-mediated protein degradation. It contains an N-terminal ubiquitin-like (UBL) domain, an xeroderma pigmentosum C (XPC)-binding domain, and a ubiquitin-associated (UBA) domain preceding and following the XPC-binding domain. Each of the four structural domains are connected by flexible linker regions. We report in this NMR study, the 1H, 15N and 13C resonance assignments for the backbone and sidechain atoms of the hHR23a full-length protein with BioMagResBank accession number 52059. Assignments are 97% and 87% for the backbone (NH, N, C', Cα, and Hα) and sidechain atoms of the hHR23a structured regions. The secondary structural elements predicted from the NMR data fit well to the hHR23a NMR structure. The assignments described in this manuscript can be used to apply NMR for studies of hHR23a with its binding partners.
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Affiliation(s)
- Xiang Chen
- Protein Processing Section, Center for Structural Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD, 21702, USA
| | - Kylie J Walters
- Protein Processing Section, Center for Structural Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD, 21702, USA.
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3
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Fay EM, Newton A, Berney M, El‐Sagheer AH, Brown T, McGouran JF. Two-Step Validation Approach for Tools To Study the DNA Repair Enzyme SNM1A. Chembiochem 2023; 24:e202200756. [PMID: 36917742 PMCID: PMC10962688 DOI: 10.1002/cbic.202200756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 03/06/2023] [Accepted: 03/14/2023] [Indexed: 03/16/2023]
Abstract
We report a two-step validation approach to evaluate the suitability of metal-binding groups for targeting DNA damage-repair metalloenzymes using model enzyme SNM1A. A fragment-based screening approach was first used to identify metal-binding fragments suitable for targeting the enzyme. Effective fragments were then incorporated into oligonucleotides using the copper-catalysed azide-alkyne cycloaddition reaction. These modified oligonucleotides were recognised by SNM1A at >1000-fold lower concentrations than their fragment counterparts. The exonuclease SNM1A is a key enzyme involved in the repair of interstrand crosslinks, a highly cytotoxic form of DNA damage. However, SNM1A and other enzymes of this class are poorly understood, as there is a lack of tools available to facilitate their study. Our novel approach of incorporating functional fragments into oligonucleotides is broadly applicable to generating modified oligonucleotide structures with high affinity for DNA damage-repair enzymes.
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Affiliation(s)
- Ellen M. Fay
- School of Chemistry and Trinity Biomedical Sciences InstituteTrinity College DublinThe University of DublinDublin 2D02 R590Ireland
| | - Ailish Newton
- School of Chemistry and Trinity Biomedical Sciences InstituteTrinity College DublinThe University of DublinDublin 2D02 R590Ireland
| | - Mark Berney
- School of Chemistry and Trinity Biomedical Sciences InstituteTrinity College DublinThe University of DublinDublin 2D02 R590Ireland
| | - Afaf H. El‐Sagheer
- Department of ChemistryUniversity of OxfordMansfield RoadOX1 3TAOxfordUK
| | - Tom Brown
- Department of ChemistryUniversity of OxfordMansfield RoadOX1 3TAOxfordUK
| | - Joanna F. McGouran
- School of Chemistry and Trinity Biomedical Sciences InstituteTrinity College DublinThe University of DublinDublin 2D02 R590Ireland
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4
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Feltes BC. Every protagonist has a sidekick: Structural aspects of human xeroderma pigmentosum-binding proteins in nucleotide excision repair. Protein Sci 2021; 30:2187-2205. [PMID: 34420242 DOI: 10.1002/pro.4173] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 08/13/2021] [Accepted: 08/17/2021] [Indexed: 12/30/2022]
Abstract
The seven xeroderma pigmentosum proteins (XPps), XPA-XPG, coordinate the nucleotide excision repair (NER) pathway, promoting the excision of DNA lesions caused by exposition to ionizing radiation, majorly from ultraviolet light. Significant efforts are made to investigate NER since mutations in any of the seven XPps may cause the xeroderma pigmentosum and trichothiodystrophy diseases. However, these proteins collaborate with other pivotal players in all known NER steps to accurately exert their purposes. Therefore, in the old and ever-evolving field of DNA repair, it is imperative to reexamine and describe their structures to understand NER properly. This work provides an up-to-date review of the protein structural aspects of the closest partners that directly interact and influence XPps: RAD23B, CETN2, DDB1, RPA (RPA70, 32, and 14), p8 (GTF2H5), and ERCC1. Structurally and functionally vital domains, regions, and critical residues are reexamined, providing structural lessons and perspectives about these indispensable proteins in the NER and other DNA repair pathways. By gathering all data related to the major human xeroderma pigmentosum-interacting proteins, this review will aid newcomers on the subject and guide structural and functional future studies.
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Affiliation(s)
- Bruno César Feltes
- Department of Theoretical Informatics, Institute of Informatics, Department of Theoretical Informatics, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
- Department of Genetics, Institute of Bioscience, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
- Department of Biophysics, Institute of Bioscience, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
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5
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Weems JC, Slaughter BD, Unruh JR, Weaver KJ, Miller BD, Delventhal KM, Conaway JW, Conaway RC. A role for the Cockayne Syndrome B (CSB)-Elongin ubiquitin ligase complex in signal-dependent RNA polymerase II transcription. J Biol Chem 2021; 297:100862. [PMID: 34116057 PMCID: PMC8294581 DOI: 10.1016/j.jbc.2021.100862] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 05/27/2021] [Accepted: 06/07/2021] [Indexed: 11/19/2022] Open
Abstract
The Elongin complex was originally identified as an RNA polymerase II (RNAPII) elongation factor and subsequently as the substrate recognition component of a Cullin-RING E3 ubiquitin ligase. More recent evidence indicates that the Elongin ubiquitin ligase assembles with the Cockayne syndrome B helicase (CSB) in response to DNA damage and can target stalled polymerases for ubiquitylation and removal from the genome. In this report, we present evidence that the CSB-Elongin ubiquitin ligase pathway has roles beyond the DNA damage response in the activation of RNAPII-mediated transcription. We observed that assembly of the CSB-Elongin ubiquitin ligase is induced not just by DNA damage, but also by a variety of signals that activate RNAPII-mediated transcription, including endoplasmic reticulum (ER) stress, amino acid starvation, retinoic acid, glucocorticoids, and doxycycline treatment of cells carrying several copies of a doxycycline-inducible reporter. Using glucocorticoid receptor (GR)-regulated genes as a model, we showed that glucocorticoid-induced transcription is accompanied by rapid recruitment of CSB and the Elongin ubiquitin ligase to target genes in a step that depends upon the presence of transcribing RNAPII on those genes. Consistent with the idea that the CSB-Elongin pathway plays a direct role in GR-regulated transcription, mouse cells lacking the Elongin subunit Elongin A exhibit delays in both RNAPII accumulation on and dismissal from target genes following glucocorticoid addition and withdrawal, respectively. Taken together, our findings bring to light a new role for the CSB-Elongin pathway in RNAPII-mediated transcription.
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Affiliation(s)
- Juston C Weems
- Stowers Institute for Medical Research, Kansas City, Missouri, USA
| | | | - Jay R Unruh
- Stowers Institute for Medical Research, Kansas City, Missouri, USA
| | - Kyle J Weaver
- Stowers Institute for Medical Research, Kansas City, Missouri, USA
| | - Brandon D Miller
- Stowers Institute for Medical Research, Kansas City, Missouri, USA
| | - Kym M Delventhal
- Stowers Institute for Medical Research, Kansas City, Missouri, USA
| | - Joan W Conaway
- Stowers Institute for Medical Research, Kansas City, Missouri, USA; Department of Biochemistry & Molecular Biology, University of Kansas Medical Center, Kansas City, Kansas, USA.
| | - Ronald C Conaway
- Stowers Institute for Medical Research, Kansas City, Missouri, USA; Department of Biochemistry & Molecular Biology, University of Kansas Medical Center, Kansas City, Kansas, USA.
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6
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Batenburg NL, Cui S, Walker JR, Schellhorn HE, Zhu XD. The Winged Helix Domain of CSB Regulates RNAPII Occupancy at Promoter Proximal Pause Sites. Int J Mol Sci 2021; 22:ijms22073379. [PMID: 33806087 PMCID: PMC8037043 DOI: 10.3390/ijms22073379] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 03/19/2021] [Accepted: 03/24/2021] [Indexed: 12/16/2022] Open
Abstract
Cockayne syndrome group B protein (CSB), a member of the SWI/SNF superfamily, resides in an elongating RNA polymerase II (RNAPII) complex and regulates transcription elongation. CSB contains a C-terminal winged helix domain (WHD) that binds to ubiquitin and plays an important role in DNA repair. However, little is known about the role of the CSB-WHD in transcription regulation. Here, we report that CSB is dependent upon its WHD to regulate RNAPII abundance at promoter proximal pause (PPP) sites of several actively transcribed genes, a key step in the regulation of transcription elongation. We show that two ubiquitin binding-defective mutations in the CSB-WHD, which impair CSB's ability to promote cell survival in response to treatment with cisplatin, have little impact on its ability to stimulate RNAPII occupancy at PPP sites. In addition, we demonstrate that two cancer-associated CSB mutations, which are located on the opposite side of the CSB-WHD away from its ubiquitin-binding pocket, impair CSB's ability to promote RNAPII occupancy at PPP sites. Taken together, these results suggest that CSB promotes RNAPII association with PPP sites in a manner requiring the CSB-WHD but independent of its ubiquitin-binding activity. These results further imply that CSB-mediated RNAPII occupancy at PPP sites is mechanistically separable from CSB-mediated repair of cisplatin-induced DNA damage.
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Affiliation(s)
| | | | | | | | - Xu-Dong Zhu
- Correspondence: ; Tel.: +1-905-525-9140 (ext. 27737)
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7
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Shi H, Ishikawa R, Heh CH, Sasaki S, Taniguchi Y. Development of MTH1-Binding Nucleotide Analogs Based on 7,8-Dihalogenated 7-Deaza-dG Derivatives. Int J Mol Sci 2021; 22:ijms22031274. [PMID: 33525366 PMCID: PMC7866122 DOI: 10.3390/ijms22031274] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 01/23/2021] [Accepted: 01/23/2021] [Indexed: 12/15/2022] Open
Abstract
MTH1 is an enzyme that hydrolyzes 8-oxo-dGTP, which is an oxidatively damaged nucleobase, into 8-oxo-dGMP in nucleotide pools to prevent its mis-incorporation into genomic DNA. Selective and potent MTH1-binding molecules have potential as biological tools and drug candidates. We recently developed 8-halogenated 7-deaza-dGTP as an 8-oxo-dGTP mimic and found that it was not hydrolyzed, but inhibited enzyme activity. To further increase MTH1 binding, we herein designed and synthesized 7,8-dihalogenated 7-deaza-dG derivatives. We successfully synthesized multiple derivatives, including substituted nucleosides and nucleotides, using 7-deaza-dG as a starting material. Evaluations of the inhibition of MTH1 activity revealed the strong inhibitory effects on enzyme activity of the 7,8-dihalogenated 7-deaza-dG derivatives, particularly 7,8-dibromo 7-daza-dGTP. Based on the results obtained on kinetic parameters and from computational docking simulating studies, these nucleotide analogs interacted with the active site of MTH1 and competitively inhibited the substrate 8-oxodGTP. Therefore, novel properties of repair enzymes in cells may be elucidated using new compounds.
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Affiliation(s)
- Hui Shi
- Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan; (H.S.); (R.I.); (S.S.)
| | - Ren Ishikawa
- Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan; (H.S.); (R.I.); (S.S.)
| | - Choon Han Heh
- Department of Pharmacy, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia;
| | - Shigeki Sasaki
- Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan; (H.S.); (R.I.); (S.S.)
- Graduate School of Pharmaceutical Sciences, Nagasaki International University, 2825-7 Huis Ten Bosch Machi, Sasebo City, Nagasaki 859-3298, Japan
| | - Yosuke Taniguchi
- Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan; (H.S.); (R.I.); (S.S.)
- Correspondence: ; Tel.: +81-92-642-6569
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8
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Dhasmana A, Dhasmana A, H HY, Farasani A, Habibullah M, Alshammary FL, Khan S, Haque S, Lohani M. Tobacco Smoke Carcinogens Induce DNA Repair Machinery Function Loss: Protection by Carbon Nanotubes. Asian Pac J Cancer Prev 2020; 21:3099-3108. [PMID: 33112573 PMCID: PMC7798159 DOI: 10.31557/apjcp.2020.21.10.3099] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 10/22/2020] [Indexed: 11/25/2022] Open
Abstract
PURPOSE DNA damage is a continuous process occurring within the cells caused by intrinsic and extrinsic factors, but it gets repaired regularly. If the DNA repair process is faulty, the incidences of damages/mutations can accumulate in cells resulting in cell transformation. It is hypothesized that the negative variations in DNA repair pathways in even at one point viz. genetic, translational or posttranslational stage may fairly be crucial for the beginning and development of carcinogenesis. Therefore, we investigated the potential of tobacco specific nitrosamines (TSNs) related carcinogens to interact with the enzymes involved in DNA repair mechanisms in the current study. METHODS The derivatives of cigarettes' smoke like NNK and NNAL are very well known and recognized carcinogens. Therefore, almost 120 enzymes playing crucial role in the DNA repair process have been analysed for their reactivity with NNK and NNAL. RESULTS The molecular docking study helped to screen out, 07 possible DNA repair enzyme targets for NNK, and 12for NNAL. Present study revealed the loss of activity of DNA repair enzymes in the presence of NNK and NNAL, and this accumulation may induce the tendency of DNA damage which can lead the transformation of exposed normal cells in to cancerous cells. This study also demonstrated the protective potential of nanoparticles like SWCNTs/MWCNTs against TSN's induced toxicity; here SWCNT against NNK (-17.16 Kcal/Mol) and MWCNT against NNK -17.01 Kcal/Mol were showing maximum binding affinities than the known biomolecular target of NNK 1UGH (Uracil-DNA glycosylase,-7.82Kcal/Mol). CONCLUSION CNTs can be applied as chemo-preventive agents against environmental and tobacco induced carcinogens owing to their scavenging potential and warrants for in vivo and in vitro experimental validation of the results obtained from the present study. .
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Affiliation(s)
- Anukriti Dhasmana
- Himalayan School of Biosciences, Swami Rama Himalayan University, Dehradun (Uttarakhand), India.
| | - Anupam Dhasmana
- Himalayan School of Biosciences, Swami Rama Himalayan University, Dehradun (Uttarakhand), India.
- University of Texas Rio Grande Valley, McAllen, United States of America.
| | - Hobani Yahya H
- Dean, Faculty of Applied Medical Sciences, Jazan University, Jazan, Saudi Arabia.
| | - Abdullah Farasani
- Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, Jazan University, Jazan, Saudi Arabia.
| | - Mahmoud Habibullah
- Emergency Medical Services Department, Faculty of Applied Medical Sciences, Jazan University, Jazan, Saudi Arabia.
| | - Freah L Alshammary
- Department of Preventative Dental Sciences, College of Dentistry, Hail University, Hail, Saudi Arabia.
| | - Saif Khan
- Department of Preventative Dental Sciences, College of Dentistry, Hail University, Hail, Saudi Arabia.
| | - Shafiul Haque
- Research and Scientific Studies Unit, Faculty of Nursing and Allied Health Sciences, Jazan University, Jazan, Saudi Arabia.
| | - Mohtashim Lohani
- Emergency Medical Services Department, Faculty of Applied Medical Sciences, Jazan University, Jazan, Saudi Arabia.
- Medical Research centre, Faculty of Applied Medical Sciences, Jazan University, Jazan, KSA.
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9
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Abstract
MacroD2 is one of the three human macrodomain proteins characterized by their protein-linked mono-ADP-ribosyl-hydrolyzing activity. MacroD2 is a single-domain protein that contains a deep ADP-ribose-binding groove. In this study, new crystallization conditions for MacroD2 were found and three crystal structures of human MacroD2 in the apo state were solved in space groups P41212, P43212 and P43, and refined at 1.75, 1.90 and 1.70 Å resolution, respectively. Structural comparison of the apo crystal structures with the previously reported crystal structure of MacroD2 in complex with ADP-ribose revealed conformational changes in the side chains of Val101, Ile189 and Phe224 induced by the binding of ADP-ribose in the active site. These conformational variations may potentially facilitate design efforts of a MacroD2 inhibitor.
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Affiliation(s)
- Sarah Wazir
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, PO Box 5400, Oulu 90014, Finland
| | - Mirko M. Maksimainen
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, PO Box 5400, Oulu 90014, Finland
| | - Lari Lehtiö
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, PO Box 5400, Oulu 90014, Finland
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10
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Wongsurawat T, Jenjaroenpun P, De Loose A, Alkam D, Ussery DW, Nookaew I, Leung YK, Ho SM, Day JD, Rodriguez A. A novel Cas9-targeted long-read assay for simultaneous detection of IDH1/2 mutations and clinically relevant MGMT methylation in fresh biopsies of diffuse glioma. Acta Neuropathol Commun 2020; 8:87. [PMID: 32563269 PMCID: PMC7305623 DOI: 10.1186/s40478-020-00963-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Accepted: 06/11/2020] [Indexed: 12/20/2022] Open
Abstract
Molecular biomarkers provide both diagnostic and prognostic results for patients with diffuse glioma, the most common primary brain tumor in adults. Here, we used a long-read nanopore-based sequencing technique to simultaneously assess IDH mutation status and MGMT methylation level in 4 human cell lines and 8 fresh human brain tumor biopsies. Currently, these biomarkers are assayed separately, and results can take days to weeks. We demonstrated the use of nanopore Cas9-targeted sequencing (nCATS) to identify IDH1 and IDH2 mutations within 36 h and compared this approach against currently used clinical methods. nCATS was also able to simultaneously provide high-resolution evaluation of MGMT methylation levels not only at the promoter region, as with currently used methods, but also at CpGs across the proximal promoter region, the entirety of exon 1, and a portion of intron 1. We compared the methylation levels of all CpGs to MGMT expression in all cell lines and tumors and observed a positive correlation between intron 1 methylation and MGMT expression. Finally, we identified single nucleotide variants in 3 target loci. This pilot study demonstrates the feasibility of using nCATS as a clinical tool for cancer precision medicine.
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Affiliation(s)
- Thidathip Wongsurawat
- Department of Biomedical Informatics, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA.
| | - Piroon Jenjaroenpun
- Department of Biomedical Informatics, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA
| | - Annick De Loose
- Department of Neurosurgery, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA
| | - Duah Alkam
- Department of Biomedical Informatics, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA
| | - David W Ussery
- Department of Biomedical Informatics, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA
| | - Intawat Nookaew
- Department of Biomedical Informatics, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA
| | - Yuet-Kin Leung
- Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA
| | - Shuk-Mei Ho
- Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA
| | - John D Day
- Department of Neurosurgery, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA
| | - Analiz Rodriguez
- Department of Neurosurgery, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA.
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11
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Scaletti ER, Vallin KS, Bräutigam L, Sarno A, Warpman Berglund U, Helleday T, Stenmark P, Jemth AS. MutT homologue 1 (MTH1) removes N6-methyl-dATP from the dNTP pool. J Biol Chem 2020; 295:4761-4772. [PMID: 32144205 PMCID: PMC7152754 DOI: 10.1074/jbc.ra120.012636] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 03/02/2020] [Indexed: 12/17/2022] Open
Abstract
MutT homologue 1 (MTH1) removes oxidized nucleotides from the nucleotide pool and thereby prevents their incorporation into the genome and thereby reduces genotoxicity. We previously reported that MTH1 is an efficient catalyst of O6-methyl-dGTP hydrolysis suggesting that MTH1 may also sanitize the nucleotide pool from other methylated nucleotides. We here show that MTH1 efficiently catalyzes the hydrolysis of N6-methyl-dATP to N6-methyl-dAMP and further report that N6-methylation of dATP drastically increases the MTH1 activity. We also observed MTH1 activity with N6-methyl-ATP, albeit at a lower level. We show that N6-methyl-dATP is incorporated into DNA in vivo, as indicated by increased N6-methyl-dA DNA levels in embryos developed from MTH1 knock-out zebrafish eggs microinjected with N6-methyl-dATP compared with noninjected embryos. N6-methyl-dATP activity is present in MTH1 homologues from distantly related vertebrates, suggesting evolutionary conservation and indicating that this activity is important. Of note, N6-methyl-dATP activity is unique to MTH1 among related NUDIX hydrolases. Moreover, we present the structure of N6-methyl-dAMP-bound human MTH1, revealing that the N6-methyl group is accommodated within a hydrophobic active-site subpocket explaining why N6-methyl-dATP is a good MTH1 substrate. N6-methylation of DNA and RNA has been reported to have epigenetic roles and to affect mRNA metabolism. We propose that MTH1 acts in concert with adenosine deaminase-like protein isoform 1 (ADAL1) to prevent incorporation of N6-methyl-(d)ATP into DNA and RNA. This would hinder potential dysregulation of epigenetic control and RNA metabolism via conversion of N6-methyl-(d)ATP to N6-methyl-(d)AMP, followed by ADAL1-catalyzed deamination producing (d)IMP that can enter the nucleotide salvage pathway.
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Affiliation(s)
- Emma Rose Scaletti
- Department of Biochemistry and Biophysics, Stockholm University S-106 91, Stockholm, Sweden
- Department of Experimental Medical Science, Lund University, Lund 221 00, Sweden
| | - Karl S Vallin
- Science for Life Laboratory, Department of Oncology-Pathology, Karolinska Institutet, S-171 76 Stockholm, Sweden
| | - Lars Bräutigam
- Science for Life Laboratory, Department of Oncology-Pathology, Karolinska Institutet, S-171 76 Stockholm, Sweden
| | - Antonio Sarno
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, 7491 Trondheim, Norway
- Department of Pathology, St. Olavs Hospital, 7006 Trondheim, Norway
| | - Ulrika Warpman Berglund
- Science for Life Laboratory, Department of Oncology-Pathology, Karolinska Institutet, S-171 76 Stockholm, Sweden
| | - Thomas Helleday
- Science for Life Laboratory, Department of Oncology-Pathology, Karolinska Institutet, S-171 76 Stockholm, Sweden
- Weston Park Cancer Centre, Department of Oncology and Metabolism, University of Sheffield, Sheffield S10 2RX, United Kingdom
| | - Pål Stenmark
- Department of Biochemistry and Biophysics, Stockholm University S-106 91, Stockholm, Sweden
- Department of Experimental Medical Science, Lund University, Lund 221 00, Sweden
| | - Ann-Sofie Jemth
- Science for Life Laboratory, Department of Oncology-Pathology, Karolinska Institutet, S-171 76 Stockholm, Sweden
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12
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Byeon IJL, Jung J, Byeon CH, DeLucia M, Ahn J, Gronenborn AM. Complete 1H, 13C, 15N resonance assignments and secondary structure of the Vpr binding region of hHR23A (residues 223-363). Biomol NMR Assign 2020; 14:13-17. [PMID: 31463759 PMCID: PMC7047585 DOI: 10.1007/s12104-019-09913-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 08/21/2019] [Indexed: 06/10/2023]
Abstract
Comprehensive resonance assignments and delineation of the secondary structure elements of the C-terminal Vpr-binding region of hHR23A, residues 223-363, were achieved by triple-resonance NMR experiments on uniformly 13C,15N-labeled protein. Assignments are 100% and > 95% complete for backbone and side-chain resonances, respectively. This data constitutes important complementary information for our ongoing structure determination of the Vpr-hHR23A(223-363) complex. At high concentrations, severe line-broadening was observed for several residues in the 1H-15N HSQC spectrum, most likely resulting from inter-molecular interactions.
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Affiliation(s)
- In-Ja L Byeon
- Department of Structural Biology, University of Pittsburgh School of Medicine, 3501 Fifth Ave., Pittsburgh, PA, 15261, USA
- Pittsburgh Center for HIV Protein Interactions, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15261, USA
| | - Jinwon Jung
- Department of Structural Biology, University of Pittsburgh School of Medicine, 3501 Fifth Ave., Pittsburgh, PA, 15261, USA
- Pittsburgh Center for HIV Protein Interactions, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15261, USA
- ABL Bio Inc., 16, Daewangpangyo-ro 712 beon-gil, Bundang-gu, Seongnam-si, Gyeonggi-do, 13488, Republic of Korea
| | - Chang H Byeon
- Department of Structural Biology, University of Pittsburgh School of Medicine, 3501 Fifth Ave., Pittsburgh, PA, 15261, USA
- Pittsburgh Center for HIV Protein Interactions, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15261, USA
| | - Maria DeLucia
- Department of Structural Biology, University of Pittsburgh School of Medicine, 3501 Fifth Ave., Pittsburgh, PA, 15261, USA
- Pittsburgh Center for HIV Protein Interactions, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15261, USA
| | - Jinwoo Ahn
- Department of Structural Biology, University of Pittsburgh School of Medicine, 3501 Fifth Ave., Pittsburgh, PA, 15261, USA
- Pittsburgh Center for HIV Protein Interactions, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15261, USA
| | - Angela M Gronenborn
- Department of Structural Biology, University of Pittsburgh School of Medicine, 3501 Fifth Ave., Pittsburgh, PA, 15261, USA.
- Pittsburgh Center for HIV Protein Interactions, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15261, USA.
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13
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de Ruyck J, Brysbaert G, Villeret V, Aumercier M, Lensink MF. Computational characterization of the binding mode between oncoprotein Ets-1 and DNA-repair enzymes. Proteins 2018; 86:1055-1063. [PMID: 30019773 PMCID: PMC6282593 DOI: 10.1002/prot.25578] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 05/17/2018] [Accepted: 06/22/2018] [Indexed: 12/27/2022]
Abstract
The Ets-1 oncoprotein is a transcription factor that promotes target gene expression in specific biological processes. Typically, Ets-1 activity is low in healthy cells, but elevated levels of expression have been found in cancerous cells, specifically related to tumor progression. Like the vast majority of the cellular effectors, Ets-1 does not act alone but in association with partners. Given the important role that is attributed to Ets-1 in major human diseases, it is crucial to identify its partners and characterize their interactions. In this context, two DNA-repair enzymes, PARP-1 and DNA-PK, have been identified recently as interaction partners of Ets-1. We here identify their binding mode by means of protein docking. The results identify the interacting surface between Ets-1 and the two DNA-repair enzymes centered on the α-helix H1 of the ETS domain, leaving α-helix H3 available to bind DNA. The models highlight a hydrophobic patch on Ets-1 at the center of the interaction interface that includes three tryptophans (Trp338, Trp356, and Trp361). We rationalize the binding mode using a series of computational analyses, including alanine scanning, molecular dynamics simulation, and residue centrality analysis. Our study constitutes a first but important step in the characterization, at the molecular level, of the interaction between an oncoprotein and DNA-repair enzymes.
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Affiliation(s)
- Jerome de Ruyck
- Biology Department University of Lille, CNRS UMR8576 UGSFLilleFrance
| | | | - Vincent Villeret
- Biology Department University of Lille, CNRS UMR8576 UGSFLilleFrance
| | - Marc Aumercier
- Biology Department University of Lille, CNRS UMR8576 UGSFLilleFrance
| | - Marc F. Lensink
- Biology Department University of Lille, CNRS UMR8576 UGSFLilleFrance
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14
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Leal A, Bogantes-Ledezma S, Ekici AB, Uebe S, Thiel CT, Sticht H, Berghoff M, Berghoff C, Morera B, Meisterernst M, Reis A. The polynucleotide kinase 3'-phosphatase gene (PNKP) is involved in Charcot-Marie-Tooth disease (CMT2B2) previously related to MED25. Neurogenetics 2018; 19:215-225. [PMID: 30039206 PMCID: PMC6280876 DOI: 10.1007/s10048-018-0555-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 07/02/2018] [Accepted: 07/05/2018] [Indexed: 11/26/2022]
Abstract
Charcot-Marie-Tooth disease (CMT) represents a heterogeneous group of hereditary peripheral neuropathies. We previously reported a CMT locus on chromosome 19q13.3 segregating with the disease in a large Costa Rican family with axonal neuropathy and autosomal recessive pattern of inheritance (CMT2B2). We proposed a homozygous missense variant in the Mediator complex 25 (MED25) gene as causative of the disease. Nevertheless, the fact that no other CMT individuals with MED25 variants were reported to date led us to reevaluate the original family. Using exome sequencing, we now identified a homozygous nonsense variant (p.Gln517ter) in the last exon of an adjacent gene, the polynucleotide kinase 3'-phosphatase (PNKP) gene. It encodes a DNA repair protein recently associated with recessive ataxia with oculomotor apraxia type 4 (AOA4) and microcephaly, seizures, and developmental delay (MCSZ). Subsequently, five unrelated Costa Rican CMT2 subjects initially identified as being heterozygous for the same MED25 variant were found to be also compound heterozygote for PNKP. All were heterozygous for the same variant found homozygous in the large family and a second one previously associated with ataxia (p.Thr408del). Detailed clinical reassessment of the initial family and the new individuals revealed in all an adult-onset slowly progressive CMT2 associated with signs of cerebellar dysfunction such as slurred speech and oculomotor involvement, but neither microcephaly, seizures, nor developmental delay. We propose that PKNP variants are the major causative variant for the CMT2 phenotype in these individuals and that the milder clinical manifestation is due to an allelic effect.
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Affiliation(s)
- Alejandro Leal
- Section of Genetics and Biotechnology, School of Biology, Universidad de Costa Rica, Sede Montes de Oca, San José, 2060, Costa Rica.
- Neuroscience Research Center, Universidad de Costa Rica, San José, Costa Rica.
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany.
| | | | - Arif B Ekici
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Steffen Uebe
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Christian T Thiel
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Heinrich Sticht
- Institute of Biochemistry, Friedrich-Alexander-Universtät Erlangen-Nürnberg, Erlangen, Germany
| | | | | | - Bernal Morera
- School of Biological Sciences, Universidad Nacional, Heredia, Costa Rica
| | | | - André Reis
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
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15
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Abstract
DNA repair is now understood to play a key role in a variety of disease states, most notably cancer. Tools for studying DNA have typically relied on traditional biochemical methods which are often laborious and indirect. Efforts to study the biology and therapeutic relevance of DNA repair pathways can be limited by such methods. Recently, specific fluorescent probes have been developed to aid in the study of DNA repair. Fluorescent probes offer the advantage of being able to directly assay for DNA repair activity in a simple, mix-and-measure format. This review will summarize the distinct classes of probe designs and their potential utility in varied research and preclinical settings.
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Affiliation(s)
- David L. Wilson
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Eric T. Kool
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
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16
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Abstract
Genomic instability in disease and its fidelity in health depend on the DNA damage response (DDR), regulated in part from the complex of meiotic recombination 11 homolog 1 (MRE11), ATP-binding cassette-ATPase (RAD50), and phosphopeptide-binding Nijmegen breakage syndrome protein 1 (NBS1). The MRE11-RAD50-NBS1 (MRN) complex forms a multifunctional DDR machine. Within its network assemblies, MRN is the core conductor for the initial and sustained responses to DNA double-strand breaks, stalled replication forks, dysfunctional telomeres, and viral DNA infection. MRN can interfere with cancer therapy and is an attractive target for precision medicine. Its conformations change the paradigm whereby kinases initiate damage sensing. Delineated results reveal kinase activation, posttranslational targeting, functional scaffolding, conformations storing binding energy and enabling access, interactions with hub proteins such as replication protein A (RPA), and distinct networks at DNA breaks and forks. MRN biochemistry provides prototypic insights into how it initiates, implements, and regulates multifunctional responses to genomic stress.
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Affiliation(s)
- Aleem Syed
- Department of Molecular and Cellular Oncology, The University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030, USA; ,
| | - John A Tainer
- Department of Molecular and Cellular Oncology, The University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030, USA; ,
- Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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17
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Abstract
The Mre11-Rad50 protein complex is an initial responder to sites of DNA double strand breaks. Many studies have shown that ATP binding to Rad50 causes global changes to the Mre11-Rad50 structure, which are important for DNA repair functions. Here we used methyl-based NMR spectroscopy on a series of mutants to describe a dynamic allosteric pathway within Rad50. Mutations result in changes in the side chain methyl group chemical environment that are correlated with altered nanosecond timescale dynamics. We also observe striking relationships between the magnitude of chemical shift perturbations and Rad50 and Mre11 activities. Together, these data suggest an equilibrium between a ground state and an "active" dimerization competent state of Rad50 that has locally altered structure and dynamics and is poised for ATP-induced dimerization and eventual ATP hydrolysis. Thus, this sparsely populated intermediate is critical for Mre11-Rad50-directed DNA double strand break repair.
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Affiliation(s)
- Zachary K Boswell
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX, 79423, USA
| | - Samiur Rahman
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX, 79423, USA
| | - Marella D Canny
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX, 79423, USA
| | - Michael P Latham
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX, 79423, USA.
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18
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Beagan K, Armstrong RL, Witsell A, Roy U, Renedo N, Baker AE, Schärer OD, McVey M. Drosophila DNA polymerase theta utilizes both helicase-like and polymerase domains during microhomology-mediated end joining and interstrand crosslink repair. PLoS Genet 2017; 13:e1006813. [PMID: 28542210 PMCID: PMC5466332 DOI: 10.1371/journal.pgen.1006813] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 06/09/2017] [Accepted: 05/12/2017] [Indexed: 11/20/2022] Open
Abstract
Double strand breaks (DSBs) and interstrand crosslinks (ICLs) are toxic DNA lesions that can be repaired through multiple pathways, some of which involve shared proteins. One of these proteins, DNA Polymerase θ (Pol θ), coordinates a mutagenic DSB repair pathway named microhomology-mediated end joining (MMEJ) and is also a critical component for bypass or repair of ICLs in several organisms. Pol θ contains both polymerase and helicase-like domains that are tethered by an unstructured central region. While the role of the polymerase domain in promoting MMEJ has been studied extensively both in vitro and in vivo, a function for the helicase-like domain, which possesses DNA-dependent ATPase activity, remains unclear. Here, we utilize genetic and biochemical analyses to examine the roles of the helicase-like and polymerase domains of Drosophila Pol θ. We demonstrate an absolute requirement for both polymerase and ATPase activities during ICL repair in vivo. However, similar to mammalian systems, polymerase activity, but not ATPase activity, is required for ionizing radiation-induced DSB repair. Using a site-specific break repair assay, we show that overall end-joining efficiency is not affected in ATPase-dead mutants, but there is a significant decrease in templated insertion events. In vitro, Pol θ can efficiently bypass a model unhooked nitrogen mustard crosslink and promote DNA synthesis following microhomology annealing, although ATPase activity is not required for these functions. Together, our data illustrate the functional importance of the helicase-like domain of Pol θ and suggest that its tethering to the polymerase domain is important for its multiple functions in DNA repair and damage tolerance. Error-prone DNA Polymerase θ (Pol θ) plays a conserved role in a mutagenic DNA double-strand break repair mechanism called microhomology-mediated end joining (MMEJ). In many organisms, it also participates in a process crucial to the removal/repair of DNA interstrand crosslinks. The exact mechanism by which Pol θ promotes these processes is unclear, but a clue may lie in its dual-domain structure. While the role of its polymerase domain has been well-studied, the function of its helicase-like domain remains an open question. Here we report an absolute requirement for ATPase activity of the helicase-like domain during interstrand crosslink repair in Drosophila melanogaster. We also find that although end joining frequency does not decrease in ATPase-dead mutants, ATPase activity is critical for generating templated insertions. Using purified Pol θ protein, we show that it can bypass synthetic substrates mimicking interstrand crosslink intermediates and can promote MMEJ-like reactions with partial double-stranded and single-stranded DNA. Together, these data demonstrate a novel function for the helicase-like domain of Pol θ in both interstrand crosslink repair and MMEJ and provide insight into why the dual-domain structure has been conserved throughout evolution.
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Affiliation(s)
- Kelly Beagan
- Department of Biology, Tufts University, Medford, Massachusetts
| | | | - Alice Witsell
- Department of Biology, Tufts University, Medford, Massachusetts
| | - Upasana Roy
- Department of Chemistry and Department of Pharmacological Sciences, Stony Brook University, Stony Brook, New York, United States of America
| | - Nikolai Renedo
- Department of Biology, Tufts University, Medford, Massachusetts
| | - Amy E. Baker
- Department of Biology, Tufts University, Medford, Massachusetts
| | - Orlando D. Schärer
- Department of Chemistry and Department of Pharmacological Sciences, Stony Brook University, Stony Brook, New York, United States of America
- Center for Genomic Integrity, Institute for Basic Science, Ulsan, Korea and Department of Biological Sciences, School of Life Sciences, Ulsan National Institute of Science and Technology, Ulsan, Korea
| | - Mitch McVey
- Department of Biology, Tufts University, Medford, Massachusetts
- * E-mail:
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19
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Deshpande RA, Lee JH, Paull TT. Rad50 ATPase activity is regulated by DNA ends and requires coordination of both active sites. Nucleic Acids Res 2017; 45:5255-5268. [PMID: 28369545 PMCID: PMC5435944 DOI: 10.1093/nar/gkx173] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 03/02/2017] [Accepted: 03/06/2017] [Indexed: 01/03/2023] Open
Abstract
The Mre11-Rad50-Nbs1(Xrs2) (MRN/X) complex is critical for the repair and signaling of DNA double strand breaks. The catalytic core of MRN/X comprised of the Mre11 nuclease and Rad50 adenosine triphosphatase (ATPase) active sites dimerizes through association between the Rad50 ATPase catalytic domains and undergoes extensive conformational changes upon ATP binding. This ATP-bound 'closed' state promotes binding to DNA, tethering DNA ends and ATM activation, but prevents nucleolytic processing of DNA ends, while ATP hydrolysis is essential for Mre11 endonuclease activity at blocked DNA ends. Here we investigate the regulation of ATP hydrolysis as well as the interdependence of the two functional active sites. We find that double-stranded DNA stimulates ATP hydrolysis by hMRN over ∼20-fold in an end-dependent manner. Using catalytic site mutants to create Rad50 dimers with only one functional ATPase site, we find that both ATPase sites are required for the stimulation by DNA. MRN-mediated endonucleolytic cleavage of DNA at sites of protein adducts requires ATP hydrolysis at both sites, as does the stimulation of ATM kinase activity. These observations suggest that symmetrical engagement of the Rad50 catalytic head domains with ATP bound at both sites is important for MRN functions in eukaryotic cells.
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Affiliation(s)
- Rajashree A. Deshpande
- Howard Hughes Medical Institute, Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA
| | - Ji-Hoon Lee
- Howard Hughes Medical Institute, Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA
| | - Tanya T. Paull
- Howard Hughes Medical Institute, Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA
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20
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Kolinjivadi AM, Sannino V, de Antoni A, Técher H, Baldi G, Costanzo V. Moonlighting at replication forks - a new life for homologous recombination proteins BRCA1, BRCA2 and RAD51. FEBS Lett 2017; 591:1083-1100. [PMID: 28079255 DOI: 10.1002/1873-3468.12556] [Citation(s) in RCA: 112] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 12/27/2016] [Accepted: 01/09/2017] [Indexed: 12/30/2022]
Abstract
Coordination between DNA replication and DNA repair ensures maintenance of genome integrity, which is lost in cancer cells. Emerging evidence has linked homologous recombination (HR) proteins RAD51, BRCA1 and BRCA2 to the stability of nascent DNA. This function appears to be distinct from double-strand break (DSB) repair and is in part due to the prevention of MRE11-mediated degradation of nascent DNA at stalled forks. The role of RAD51 in fork protection resembles the activity described for its prokaryotic orthologue RecA, which prevents nuclease-mediated degradation of DNA and promotes replication fork restart in cells challenged by DNA-damaging agents. Here, we examine the mechanistic aspects of HR-mediated fork protection, addressing the crosstalk between HR and replication proteins.
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Affiliation(s)
| | - Vincenzo Sannino
- DNA metabolism laboratory, IFOM-The Firc Institute of Molecular Oncology, Milan, Italy
| | - Anna de Antoni
- DNA metabolism laboratory, IFOM-The Firc Institute of Molecular Oncology, Milan, Italy
| | - Hervé Técher
- DNA metabolism laboratory, IFOM-The Firc Institute of Molecular Oncology, Milan, Italy
| | - Giorgio Baldi
- DNA metabolism laboratory, IFOM-The Firc Institute of Molecular Oncology, Milan, Italy
| | - Vincenzo Costanzo
- DNA metabolism laboratory, IFOM-The Firc Institute of Molecular Oncology, Milan, Italy
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21
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Park YB, Hohl M, Padjasek M, Jeong E, Jin KS, Krężel A, Petrini JHJ, Cho Y. Eukaryotic Rad50 functions as a rod-shaped dimer. Nat Struct Mol Biol 2017; 24:248-257. [PMID: 28134932 PMCID: PMC5625350 DOI: 10.1038/nsmb.3369] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 01/05/2017] [Indexed: 11/08/2022]
Abstract
The Rad50 hook interface is crucial for assembly and various functions of the Mre11 complex. Previous analyses suggested that Rad50 molecules interact within (intracomplex) or between (intercomplex) dimeric complexes. In this study, we determined the structure of the human Rad50 hook and coiled-coil domains. The data suggest that the predominant structure is the intracomplex, in which the two parallel coiled coils proximal to the hook form a rod shape, and that a novel interface within the coiled-coil domains of Rad50 stabilizes the interaction of Rad50 protomers in the dimeric assembly. In yeast, removal of the coiled-coil interface compromised Tel1 activation without affecting DNA repair, while simultaneous disruption of that interface and the hook phenocopied a null mutation. The results demonstrate that the hook and coiled-coil interfaces coordinately promote intracomplex assembly and define the intracomplex as the functional form of the Mre11 complex.
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Affiliation(s)
- Young Bong Park
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, South Korea
| | - Marcel Hohl
- Molecular Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York, USA
| | - Michał Padjasek
- Laboratory of Chemical Biology, University of Wrocław, Wrocław, Poland
| | - Eunyoung Jeong
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, South Korea
| | - Kyeong Sik Jin
- Pohang Accelerator Laboratory, Pohang University of Science and Technology, Pohang, South Korea
| | - Artur Krężel
- Laboratory of Chemical Biology, University of Wrocław, Wrocław, Poland
| | - John H J Petrini
- Molecular Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York, USA
| | - Yunje Cho
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, South Korea
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22
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Henrich SM, Usadel C, Werwein E, Burdova K, Janscak P, Ferrari S, Hess D, Klempnauer KH. Interplay with the Mre11-Rad50-Nbs1 complex and phosphorylation by GSK3β implicate human B-Myb in DNA-damage signaling. Sci Rep 2017; 7:41663. [PMID: 28128338 PMCID: PMC5269693 DOI: 10.1038/srep41663] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 12/21/2016] [Indexed: 12/30/2022] Open
Abstract
B-Myb, a highly conserved member of the Myb transcription factor family, is expressed ubiquitously in proliferating cells and controls the cell cycle dependent transcription of G2/M-phase genes. Deregulation of B-Myb has been implicated in oncogenesis and loss of genomic stability. We have identified B-Myb as a novel interaction partner of the Mre11-Rad50-Nbs1 (MRN) complex, a key player in the repair of DNA double strand breaks. We show that B-Myb directly interacts with the Nbs1 subunit of the MRN complex and is recruited transiently to DNA-damage sites. In response to DNA-damage B-Myb is phosphorylated by protein kinase GSK3β and released from the MRN complex. A B-Myb mutant that cannot be phosphorylated by GSK3β disturbs the regulation of pro-mitotic B-Myb target genes and leads to inappropriate mitotic entry in response to DNA-damage. Overall, our work suggests a novel function of B-Myb in the cellular DNA-damage signalling.
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Affiliation(s)
- Sarah Marie Henrich
- Institut for Biochemistry, Westfälische-Wilhelms-Universität, D-48149 Münster, Germany
- Graduate School of Chemistry (GSC-MS), Westfälische-Wilhelms-Universität, D-48149 Münster, Germany
| | - Clemens Usadel
- Institut for Biochemistry, Westfälische-Wilhelms-Universität, D-48149 Münster, Germany
| | - Eugen Werwein
- Institut for Biochemistry, Westfälische-Wilhelms-Universität, D-48149 Münster, Germany
| | - Kamila Burdova
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, 143 00 Prague, Czech Republic
| | - Pavel Janscak
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, 143 00 Prague, Czech Republic
- Institute of Molecular Cancer Research, University of Zurich, Winterthurerstr.190, CH-8057 Zürich, Switzerland
| | - Stefano Ferrari
- Institute of Molecular Cancer Research, University of Zurich, Winterthurerstr.190, CH-8057 Zürich, Switzerland
| | - Daniel Hess
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstr. 66, CH-4058 Basel, Switzerland
| | - Karl-Heinz Klempnauer
- Institut for Biochemistry, Westfälische-Wilhelms-Universität, D-48149 Münster, Germany
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23
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Chang HHY, Watanabe G, Gerodimos CA, Ochi T, Blundell TL, Jackson SP, Lieber MR. Different DNA End Configurations Dictate Which NHEJ Components Are Most Important for Joining Efficiency. J Biol Chem 2016; 291:24377-24389. [PMID: 27703001 PMCID: PMC5114395 DOI: 10.1074/jbc.m116.752329] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Revised: 09/26/2016] [Indexed: 02/02/2023] Open
Abstract
The nonhomologous DNA end-joining (NHEJ) pathway is a key mechanism for repairing dsDNA breaks that occur often in eukaryotic cells. In the simplest model, these breaks are first recognized by Ku, which then interacts with other NHEJ proteins to improve their affinity at DNA ends. These include DNA-PKcs and Artemis for trimming the DNA ends; DNA polymerase μ and λ to add nucleotides; and the DNA ligase IV complex to ligate the ends with the additional factors, XRCC4 (X-ray repair cross-complementing protein 4), XLF (XRCC4-like factor/Cernunos), and PAXX (paralog of XRCC4 and XLF). In vivo studies have demonstrated the degrees of importance of these NHEJ proteins in the mechanism of repair of dsDNA breaks, but interpretations can be confounded by other cellular processes. In vitro studies with NHEJ proteins have been performed to evaluate the nucleolytic resection, polymerization, and ligation steps, but a complete system has been elusive. Here we have developed a NHEJ reconstitution system that includes the nuclease, polymerase, and ligase components to evaluate relative NHEJ efficiency and analyze ligated junctional sequences for various types of DNA ends, including blunt, 5' overhangs, and 3' overhangs. We find that different dsDNA end structures have differential dependence on these enzymatic components. The dependence of some end joining on only Ku and XRCC4·DNA ligase IV allows us to formulate a physical model that incorporates nuclease and polymerase components as needed.
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Affiliation(s)
- Howard H Y Chang
- From the Departments of Pathology, Biochemistry & Molecular Biology, and Molecular Microbiology & Immunology and the Section of Molecular & Computational Biology, Department of Biological Sciences, Norris Comprehensive Cancer Center, University of Southern California Keck School of Medicine, Los Angeles, CA, 90033 and
| | - Go Watanabe
- From the Departments of Pathology, Biochemistry & Molecular Biology, and Molecular Microbiology & Immunology and the Section of Molecular & Computational Biology, Department of Biological Sciences, Norris Comprehensive Cancer Center, University of Southern California Keck School of Medicine, Los Angeles, CA, 90033 and
| | - Christina A Gerodimos
- From the Departments of Pathology, Biochemistry & Molecular Biology, and Molecular Microbiology & Immunology and the Section of Molecular & Computational Biology, Department of Biological Sciences, Norris Comprehensive Cancer Center, University of Southern California Keck School of Medicine, Los Angeles, CA, 90033 and
| | - Takashi Ochi
- the Gurdon Institute and Department of Biochemistry, University of Cambridge, Cambridge CB2 1QN, United Kingdom
| | - Tom L Blundell
- the Gurdon Institute and Department of Biochemistry, University of Cambridge, Cambridge CB2 1QN, United Kingdom
| | - Stephen P Jackson
- the Gurdon Institute and Department of Biochemistry, University of Cambridge, Cambridge CB2 1QN, United Kingdom
| | - Michael R Lieber
- From the Departments of Pathology, Biochemistry & Molecular Biology, and Molecular Microbiology & Immunology and the Section of Molecular & Computational Biology, Department of Biological Sciences, Norris Comprehensive Cancer Center, University of Southern California Keck School of Medicine, Los Angeles, CA, 90033 and.
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24
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Wang B, Francis J, Sharma M, Law SM, Predeus AV, Feig M. Long-Range Signaling in MutS and MSH Homologs via Switching of Dynamic Communication Pathways. PLoS Comput Biol 2016; 12:e1005159. [PMID: 27768684 PMCID: PMC5074593 DOI: 10.1371/journal.pcbi.1005159] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 09/21/2016] [Indexed: 11/19/2022] Open
Abstract
Allostery is conformation regulation by propagating a signal from one site to another distal site. This study focuses on the long-range communication in DNA mismatch repair proteins MutS and its homologs where intramolecular signaling has to travel over 70 Å to couple lesion detection to ATPase activity and eventual downstream repair. Using dynamic network analysis based on extensive molecular dynamics simulations, multiple preserved communication pathways were identified that would allow such long-range signaling. The pathways appear to depend on the nucleotides bound to the ATPase domain as well as the type of DNA substrate consistent with previously proposed functional cycles of mismatch recognition and repair initiation by MutS and homologs. A mechanism is proposed where pathways are switched without major conformational rearrangements allowing for efficient long-range signaling and allostery.
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Affiliation(s)
- Beibei Wang
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI, United States
| | - Joshua Francis
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI, United States
| | - Monika Sharma
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI, United States
| | - Sean M. Law
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI, United States
| | - Alexander V. Predeus
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI, United States
| | - Michael Feig
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI, United States
- * E-mail:
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25
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Stewart JJP. A method for predicting individual residue contributions to enzyme specificity and binding-site energies, and its application to MTH1. J Mol Model 2016; 22:259. [PMID: 27714533 PMCID: PMC5054044 DOI: 10.1007/s00894-016-3119-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 09/08/2016] [Indexed: 12/20/2022]
Abstract
A new method for predicting the energy contributions to substrate binding and to specificity has been developed. Conventional global optimization methods do not permit the subtle effects responsible for these properties to be modeled with sufficient precision to allow confidence to be placed in the results, but by making simple alterations to the model, the precisions of the various energies involved can be improved from about ±2 kcal mol−1 to ±0.1 kcal mol−1. This technique was applied to the oxidized nucleotide pyrophosphohydrolase enzyme MTH1. MTH1 is unusual in that the binding and reaction sites are well separated—an advantage from a computational chemistry perspective, as it allows the energetics involved in docking to be modeled without the need to consider any issues relating to reaction mechanisms. In this study, two types of energy terms were investigated: the noncovalent interactions between the binding site and the substrate, and those responsible for discriminating between the oxidized nucleotide 8-oxo-dGTP and the normal dGTP. Both of these were investigated using the semiempirical method PM7 in the program MOPAC. The contributions of the individual residues to both the binding energy and the specificity of MTH1 were calculated by simulating the effect of mutations. Where comparisons were possible, all calculated results were in agreement with experimental observations. This technique provides fresh insight into the binding mechanism that enzymes use for discriminating between possible substrates.
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Affiliation(s)
- James J P Stewart
- Stewart Computational Chemistry, 15210 Paddington Circle, Colorado Springs, CO, 80921, USA.
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26
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Abstract
Modern computational chemistry methods provide a powerful tool for use in refining the geometry of proteins determined by X-ray crystallography. Specifically, computational methods can be used to correctly place hydrogen atoms unresolved by this experimental method and improve bond geometry accuracy. Using the semiempirical method PM7, the structure of the nucleotide-sanitizing enzyme MTH1, complete with hydrolyzed substrate 8-oxo-dGMP, was optimized and the resulting geometry compared with the original X-ray structure of MTH1. After determining hydrogen atom placement and the identification of ionized sites, the charge distribution in the binding site was explored. Where comparison was possible, all the theoretical predictions were in good agreement with experimental observations. However, when these were combined with additional predictions for which experimental observations were not available, the result was a new and alternative description of the substrate-binding site interaction. An estimate was made of the strengths and weaknesses of the PM7 method for modeling proteins on varying scales, ranging from overall structure to individual interatomic distances. An attempt to correct a known fault in PM7, the under-estimation of steric repulsion, is also described. This work sheds light on the specificity of the enzyme MTH1 toward the substrate 8-oxo-dGTP; information that would facilitate drug development involving MTH1. Graphical Abstract Overlay of the backbone traces of the two MTH1 protein chains (green and orange respectively) in PDB 3ZR0 and the equivalent PM7 structures (magenta and cyan respectively) each optimized separately.
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Affiliation(s)
- Hannah Ryan
- Department of Chemistry and Biochemistry, University of Colorado Colorado Springs, Colorado Springs, CO, 80918, USA
| | - Megan Carter
- Department of Chemistry and Biochemistry, University of Colorado Colorado Springs, Colorado Springs, CO, 80918, USA
- Department of Biochemistry and Biophysics, Stockholm University, S-106 91, Stockholm, Sweden
| | - Pål Stenmark
- Department of Biochemistry and Biophysics, Stockholm University, S-106 91, Stockholm, Sweden
| | - James J P Stewart
- Stewart Computational Chemistry, 15210 Paddington Circle, Colorado Springs, CO, 80921, USA
| | - Sonja B Braun-Sand
- In Silico Chemical Consulting, 128 Longwood Ave, Lakeway, TX, 78734, USA.
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Kinoshita E, van Rossum-Fikkert S, Sanchez H, Kertokalio A, Wyman C. Human RAD50 makes a functional DNA-binding complex. Biochimie 2015; 113:47-53. [PMID: 25828805 DOI: 10.1016/j.biochi.2015.03.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2014] [Accepted: 03/20/2015] [Indexed: 11/17/2022]
Abstract
The MRE11-RAD50-NBS1 (MRN) complex has several distinct functions in DNA repair including important roles in both non-homologous end-joining (NHEJ) and homologous recombination (HR). The biochemical activities of MR(N) have been well characterized implying specific functional roles for the components. The arrangement of proteins in the complex implies interdependence of their biochemical activities making it difficult to separate specific functions. We obtained purified human RAD50 and observed that it binds ATP, undergoes ATP-dependent conformational changes as well as having ATPase activity. Scanning force microscopy analysis clearly showed that RAD50 binds DNA although not as oligomers. RAD50 alone was not functional in tethering DNA molecules. ATP increased formation of RAD50 multimers which were however globular lacking extended coiled coils, in contrast to the MR complex where ATP induced oligomers have obvious coiled coils protruding from a central domain. These results suggest that MRE11 is important in maintaining the structural arrangement of RAD50 in the protein complex and perhaps has a role in reinforcing proper alignment of the coiled coils in the ATP-bound state.
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Affiliation(s)
- Eri Kinoshita
- Department of Genetics, Cancer Genomics Center, Erasmus MC, PO Box 2040, 3000 CA Rotterdam, The Netherlands
| | - Sari van Rossum-Fikkert
- Department of Genetics, Cancer Genomics Center, Erasmus MC, PO Box 2040, 3000 CA Rotterdam, The Netherlands
| | - Humberto Sanchez
- Department of Genetics, Cancer Genomics Center, Erasmus MC, PO Box 2040, 3000 CA Rotterdam, The Netherlands
| | - Aryandi Kertokalio
- Department of Genetics, Cancer Genomics Center, Erasmus MC, PO Box 2040, 3000 CA Rotterdam, The Netherlands
| | - Claire Wyman
- Department of Genetics, Cancer Genomics Center, Erasmus MC, PO Box 2040, 3000 CA Rotterdam, The Netherlands; Department of Radiation Oncology, Erasmus MC, PO Box 2040, 3000 CA Rotterdam, The Netherlands.
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29
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Lafrance-Vanasse J, Williams GJ, Tainer JA. Envisioning the dynamics and flexibility of Mre11-Rad50-Nbs1 complex to decipher its roles in DNA replication and repair. Prog Biophys Mol Biol 2015; 117:182-193. [PMID: 25576492 PMCID: PMC4417436 DOI: 10.1016/j.pbiomolbio.2014.12.004] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Revised: 12/20/2014] [Accepted: 12/28/2014] [Indexed: 12/23/2022]
Abstract
The Mre11-Rad50-Nbs1 (MRN) complex is a dynamic macromolecular machine that acts in the first steps of DNA double strand break repair, and each of its components has intrinsic dynamics and flexibility properties that are directly linked with their functions. As a result, deciphering the functional structural biology of the MRN complex is driving novel and integrated technologies to define the dynamic structural biology of protein machinery interacting with DNA. Rad50 promotes dramatic long-range allostery through its coiled-coil and zinc-hook domains. Its ATPase activity drives dynamic transitions between monomeric and dimeric forms that can be modulated with mutants modifying the ATPase rate to control end joining versus resection activities. The biological functions of Mre11's dual endo- and exonuclease activities in repair pathway choice were enigmatic until recently, when they were unveiled by the development of specific nuclease inhibitors. Mre11 dimer flexibility, which may be regulated in cells to control MRN function, suggests new inhibitor design strategies for cancer intervention. Nbs1 has FHA and BRCT domains to bind multiple interaction partners that further regulate MRN. One of them, CtIP, modulates the Mre11 excision activity for homologous recombination repair. Overall, these combined properties suggest novel therapeutic strategies. Furthermore, they collectively help to explain how MRN regulates DNA repair pathway choice with implications for improving the design and analysis of cancer clinical trials that employ DNA damaging agents or target the DNA damage response.
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Affiliation(s)
| | | | - John A Tainer
- Life Science Division, 1 Cyclotron Road, Berkeley, CA 94720, USA; The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.
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Yu S, Chen L, Ye L, Fei L, Tang W, Tian Y, Geng Q, Yi X, Xie J. Identification of two missense mutations of ERCC6 in three Chinese sisters with Cockayne syndrome by whole exome sequencing. PLoS One 2014; 9:e113914. [PMID: 25463447 PMCID: PMC4252064 DOI: 10.1371/journal.pone.0113914] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Accepted: 10/31/2014] [Indexed: 11/18/2022] Open
Abstract
Cockayne syndrome (CS) is a rare autosomal recessive disorder, the primary manifestations of which are poor growth and neurologic abnormality. Mutations of the ERCC6 and ERCC8 genes are the predominant cause of Cockayne syndrome, and the ERCC6 gene mutation is present in approximately 65% of cases. The present report describes a case of Cockayne syndrome in a Chinese family, with the patients carrying two missense mutations (c.1595A>G, p.Asp532Gly and c.1607T>G, p.Leu536Trp) in the ERCC6 gene in an apparently compound heterozygote status, especially, p.Asp532Gly has never been reported. The compound heterozygote mutation was found in three patients in the family using whole exome sequencing. The patients' father and mother carried a heterozygous allele at different locations of the ERCC6 gene, which was confirmed by Sanger DNA sequencing. The two mutations are both located in the highly conserved motif I of ATP-binding helicase and are considered "Damaging," "Probably Damaging," "Disease Causing," and "Conserved", indicating the role of DNA damage in the pathogenetic process of the disease. The results not only enrich the ERCC6 mutations database, but also indicate that whole exome sequencing will be a powerful tool for discovering the disease causing mutations in clinical diagnosis.
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Affiliation(s)
| | - Liyuan Chen
- Prenatal Diagnosis Center, Shenzhen Maternity and Child Healthcare Hospital, Shenzhen, 518048, China
| | - Lili Ye
- BGI-shenzhen, Shenzhen, 518083, China
| | | | - Wei Tang
- BGI-shenzhen, Shenzhen, 518083, China
| | | | - Qian Geng
- Prenatal Diagnosis Center, Shenzhen Maternity and Child Healthcare Hospital, Shenzhen, 518048, China
| | - Xin Yi
- BGI-shenzhen, Shenzhen, 518083, China
- * E-mail: (JX); (XY)
| | - Jiansheng Xie
- Prenatal Diagnosis Center, Shenzhen Maternity and Child Healthcare Hospital, Shenzhen, 518048, China
- * E-mail: (JX); (XY)
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31
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Paull TT, Deshpande RA. The Mre11/Rad50/Nbs1 complex: recent insights into catalytic activities and ATP-driven conformational changes. Exp Cell Res 2014; 329:139-47. [PMID: 25016281 PMCID: PMC4252570 DOI: 10.1016/j.yexcr.2014.07.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Accepted: 07/01/2014] [Indexed: 10/25/2022]
Abstract
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
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Affiliation(s)
- Tanya T Paull
- The Howard Hughes Medical Institute, The Department of Molecular Biosciences, The Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX 78712, USA.
| | - Rajashree A Deshpande
- The Howard Hughes Medical Institute, The Department of Molecular Biosciences, The Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX 78712, USA
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Perina D, Mikoč A, Ahel J, Ćetković H, Žaja R, Ahel I. Distribution of protein poly(ADP-ribosyl)ation systems across all domains of life. DNA Repair (Amst) 2014; 23:4-16. [PMID: 24865146 PMCID: PMC4245714 DOI: 10.1016/j.dnarep.2014.05.003] [Citation(s) in RCA: 121] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 04/04/2014] [Accepted: 05/06/2014] [Indexed: 02/08/2023]
Abstract
Poly(ADP-ribosyl)ation is a post-translational modification of proteins involved in regulation of many cellular pathways. Poly(ADP-ribose) (PAR) consists of chains of repeating ADP-ribose nucleotide units and is synthesized by the family of enzymes called poly(ADP-ribose) polymerases (PARPs). This modification can be removed by the hydrolytic action of poly(ADP-ribose) glycohydrolase (PARG) and ADP-ribosylhydrolase 3 (ARH3). Hydrolytic activity of macrodomain proteins (MacroD1, MacroD2 and TARG1) is responsible for the removal of terminal ADP-ribose unit and for complete reversion of protein ADP-ribosylation. Poly(ADP-ribosyl)ation is widely utilized in eukaryotes and PARPs are present in representatives from all six major eukaryotic supergroups, with only a small number of eukaryotic species that do not possess PARP genes. The last common ancestor of all eukaryotes possessed at least five types of PARP proteins that include both mono and poly(ADP-ribosyl) transferases. Distribution of PARGs strictly follows the distribution of PARP proteins in eukaryotic species. At least one of the macrodomain proteins that hydrolyse terminal ADP-ribose is also always present. Therefore, we can presume that the last common ancestor of all eukaryotes possessed a fully functional and reversible PAR metabolism and that PAR signalling provided the conditions essential for survival of the ancestral eukaryote in its ancient environment. PARP proteins are far less prevalent in bacteria and were probably gained through horizontal gene transfer. Only eleven bacterial species possess all proteins essential for a functional PAR metabolism, although it is not known whether PAR metabolism is truly functional in bacteria. Several dsDNA viruses also possess PARP homologues, while no PARP proteins have been identified in any archaeal genome. Our analysis of the distribution of enzymes involved in PAR metabolism provides insight into the evolution of these important signalling systems, as well as providing the basis for selection of the appropriate genetic model organisms to study the physiology of the specific human PARP proteins.
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Affiliation(s)
- Dragutin Perina
- Division of Molecular Biology, Ruđer Bošković Institute, Zagreb 10002, Croatia
| | - Andreja Mikoč
- Division of Molecular Biology, Ruđer Bošković Institute, Zagreb 10002, Croatia
| | - Josip Ahel
- Division of Molecular Biology, Ruđer Bošković Institute, Zagreb 10002, Croatia
| | - Helena Ćetković
- Division of Molecular Biology, Ruđer Bošković Institute, Zagreb 10002, Croatia
| | - Roko Žaja
- Division for Marine and Environmental Research, Ruđer Bošković Institute, Zagreb 10002, Croatia; Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Ivan Ahel
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK.
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Al-Ahmadie H, Iyer G, Hohl M, Asthana S, Inagaki A, Schultz N, Hanrahan AJ, Scott SN, Brannon AR, McDermott GC, Pirun M, Ostrovnaya I, Kim P, Socci ND, Viale A, Schwartz GK, Reuter V, Bochner BH, Rosenberg JE, Bajorin DF, Berger MF, Petrini JHJ, Solit DB, Taylor BS. Synthetic lethality in ATM-deficient RAD50-mutant tumors underlies outlier response to cancer therapy. Cancer Discov 2014; 4:1014-21. [PMID: 24934408 PMCID: PMC4155059 DOI: 10.1158/2159-8290.cd-14-0380] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
UNLABELLED Metastatic solid tumors are almost invariably fatal. Patients with disseminated small-cell cancers have a particularly unfavorable prognosis, with most succumbing to their disease within two years. Here, we report on the genetic and functional analysis of an outlier curative response of a patient with metastatic small-cell cancer to combined checkpoint kinase 1 (CHK1) inhibition and DNA-damaging chemotherapy. Whole-genome sequencing revealed a clonal hemizygous mutation in the Mre11 complex gene RAD50 that attenuated ATM signaling which in the context of CHK1 inhibition contributed, via synthetic lethality, to extreme sensitivity to irinotecan. As Mre11 mutations occur in a diversity of human tumors, the results suggest a tumor-specific combination therapy strategy in which checkpoint inhibition in combination with DNA-damaging chemotherapy is synthetically lethal in tumor cells but not normal cells with somatic mutations that impair Mre11 complex function. SIGNIFICANCE Strategies to effect deep and lasting responses to cancer therapy in patients with metastatic disease have remained difficult to attain, especially in early-phase clinical trials. Here, we present an in-depth genomic and functional genetic analysis identifying RAD50 hypomorphism as a contributing factor to a curative response to systemic combination therapy in a patient with recurrent, metastatic small-cell cancer.
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Affiliation(s)
- Hikmat Al-Ahmadie
- Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Gopa Iyer
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York. Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, New York. Department of Medicine, Weill Cornell Medical College, New York, New York
| | - Marcel Hohl
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Saurabh Asthana
- Department of Medicine, University of California, San Francisco, California. Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, California
| | - Akiko Inagaki
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Nikolaus Schultz
- Computational Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Aphrothiti J Hanrahan
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Sasinya N Scott
- Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, New York
| | - A Rose Brannon
- Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Gregory C McDermott
- Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Mono Pirun
- Bioinformatics Core Laboratory, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Irina Ostrovnaya
- Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Philip Kim
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, New York. Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Nicholas D Socci
- Bioinformatics Core Laboratory, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Agnes Viale
- Genomics Core Laboratory, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Gary K Schwartz
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Victor Reuter
- Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Bernard H Bochner
- Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Jonathan E Rosenberg
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York. Department of Medicine, Weill Cornell Medical College, New York, New York
| | - Dean F Bajorin
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York. Department of Medicine, Weill Cornell Medical College, New York, New York
| | - Michael F Berger
- Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, New York. Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, New York
| | - John H J Petrini
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York.
| | - David B Solit
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York. Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, New York. Department of Medicine, Weill Cornell Medical College, New York, New York.
| | - Barry S Taylor
- Department of Medicine, University of California, San Francisco, California. Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, California. Department of Epidemiology and Biostatistics, University of California, San Francisco, California.
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Bryan DS, Ransom M, Adane B, York K, Hesselberth JR. High resolution mapping of modified DNA nucleobases using excision repair enzymes. Genome Res 2014; 24:1534-42. [PMID: 25015380 PMCID: PMC4158761 DOI: 10.1101/gr.174052.114] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 07/08/2014] [Indexed: 12/20/2022]
Abstract
The incorporation and creation of modified nucleobases in DNA have profound effects on genome function. We describe methods for mapping positions and local content of modified DNA nucleobases in genomic DNA. We combined in vitro nucleobase excision with massively parallel DNA sequencing (Excision-seq) to determine the locations of modified nucleobases in genomic DNA. We applied the Excision-seq method to map uracil in E. coli and budding yeast and discovered significant variation in uracil content, wherein uracil is excluded from the earliest and latest replicating regions of the genome, possibly driven by changes in nucleotide pool composition. We also used Excision-seq to identify sites of pyrimidine dimer formation induced by UV light exposure, where the method could distinguish between sites of cyclobutane and 6-4 photoproduct formation. These UV mapping data enabled analysis of local sequence bias around pyrimidine dimers and suggested a preference for an adenosine downstream from 6-4 photoproducts. The Excision-seq method is broadly applicable for high precision, genome-wide mapping of modified nucleobases with cognate repair enzymes.
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Affiliation(s)
- D Suzi Bryan
- Department of Biochemistry and Molecular Genetics, Program in Molecular Biology, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
| | - Monica Ransom
- Department of Biochemistry and Molecular Genetics, Program in Molecular Biology, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
| | - Biniam Adane
- Department of Biochemistry and Molecular Genetics, Program in Molecular Biology, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
| | - Kerri York
- Department of Biochemistry and Molecular Genetics, Program in Molecular Biology, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
| | - Jay R Hesselberth
- Department of Biochemistry and Molecular Genetics, Program in Molecular Biology, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
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Perevozchikova SA, Trikin RM, Heinze RJ, Romanova EA, Oretskaya TS, Friedhoff P, Kubareva EA. Is thymidine glycol containing DNA a substrate of E. coli DNA mismatch repair system? PLoS One 2014; 9:e104963. [PMID: 25133614 PMCID: PMC4136841 DOI: 10.1371/journal.pone.0104963] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Accepted: 07/15/2014] [Indexed: 11/18/2022] Open
Abstract
The DNA mismatch repair (MMR) system plays a crucial role in the prevention of replication errors and in the correction of some oxidative damages of DNA bases. In the present work the most abundant oxidized pyrimidine lesion, 5,6-dihydro-5,6-dihydroxythymidine (thymidine glycol, Tg) was tested for being recognized and processed by the E. coli MMR system, namely complex of MutS, MutL and MutH proteins. In a partially reconstituted MMR system with MutS-MutL-MutH proteins, G/Tg and A/Tg containing plasmids failed to provoke the incision of DNA. Tg residue in the 30-mer DNA duplex destabilized double helix due to stacking disruption with neighboring bases. However, such local structural changes are not important for E. coli MMR system to recognize this lesion. A lack of repair of Tg containing DNA could be due to a failure of MutS (a first acting protein of MMR system) to interact with modified DNA in a proper way. It was shown that Tg in DNA does not affect on ATPase activity of MutS. On the other hand, MutS binding affinities to DNA containing Tg in G/Tg and A/Tg pairs are lower than to DNA with a G/T mismatch and similar to canonical DNA. Peculiarities of MutS interaction with DNA was monitored by Förster resonance energy transfer (FRET) and fluorescence anisotropy. Binding of MutS to Tg containing DNAs did not result in the formation of characteristic DNA kink. Nevertheless, MutS homodimer orientation on Tg-DNA is similar to that in the case of G/T-DNA. In contrast to G/T-DNA, neither G/Tg- nor A/Tg-DNA was able to stimulate ADP release from MutS better than canonical DNA. Thus, Tg residue in DNA is unlikely to be recognized or processed by the E. coli MMR system. Probably, the MutS transformation to active “sliding clamp” conformation on Tg-DNA is problematic.
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Affiliation(s)
- Svetlana A. Perevozchikova
- Department of Chemistry and Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Roman M. Trikin
- Institute of Cell Biology, University of Bern, Bern, Switzerland
| | - Roger J. Heinze
- Institute for Biochemistry, Justus Liebig University, Giessen, Germany
| | - Elena A. Romanova
- Department of Chemistry and Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Tatiana S. Oretskaya
- Department of Chemistry and Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Peter Friedhoff
- Institute for Biochemistry, Justus Liebig University, Giessen, Germany
| | - Elena A. Kubareva
- Department of Chemistry and Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
- * E-mail:
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36
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Ezzatizadeh V, Sandi C, Sandi M, Anjomani-Virmouni S, Al-Mahdawi S, Pook MA. MutLα heterodimers modify the molecular phenotype of Friedreich ataxia. PLoS One 2014; 9:e100523. [PMID: 24971578 PMCID: PMC4074104 DOI: 10.1371/journal.pone.0100523] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 05/28/2014] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND Friedreich ataxia (FRDA), the most common autosomal recessive ataxia disorder, is caused by a dynamic GAA repeat expansion mutation within intron 1 of FXN gene, resulting in down-regulation of frataxin expression. Studies of cell and mouse models have revealed a role for the mismatch repair (MMR) MutS-heterodimer complexes and the PMS2 component of the MutLα complex in the dynamics of intergenerational and somatic GAA repeat expansions: MSH2, MSH3 and MSH6 promote GAA repeat expansions, while PMS2 inhibits GAA repeat expansions. METHODOLOGY/PRINCIPAL FINDINGS To determine the potential role of the other component of the MutLα complex, MLH1, in GAA repeat instability in FRDA, we have analyzed intergenerational and somatic GAA repeat expansions from FXN transgenic mice that have been crossed with Mlh1 deficient mice. We find that loss of Mlh1 activity reduces both intergenerational and somatic GAA repeat expansions. However, we also find that loss of either Mlh1 or Pms2 reduces FXN transcription, suggesting different mechanisms of action for Mlh1 and Pms2 on GAA repeat expansion dynamics and regulation of FXN transcription. CONCLUSIONS/SIGNIFICANCE Both MutLα components, PMS2 and MLH1, have now been shown to modify the molecular phenotype of FRDA. We propose that upregulation of MLH1 or PMS2 could be potential FRDA therapeutic approaches to increase FXN transcription.
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Affiliation(s)
- Vahid Ezzatizadeh
- Division of Biosciences, School of Health Sciences and Social Care, Brunel University London, Uxbridge, United Kingdom
| | - Chiranjeevi Sandi
- Division of Biosciences, School of Health Sciences and Social Care, Brunel University London, Uxbridge, United Kingdom
| | - Madhavi Sandi
- Division of Biosciences, School of Health Sciences and Social Care, Brunel University London, Uxbridge, United Kingdom
| | - Sara Anjomani-Virmouni
- Division of Biosciences, School of Health Sciences and Social Care, Brunel University London, Uxbridge, United Kingdom
| | - Sahar Al-Mahdawi
- Division of Biosciences, School of Health Sciences and Social Care, Brunel University London, Uxbridge, United Kingdom
| | - Mark A. Pook
- Division of Biosciences, School of Health Sciences and Social Care, Brunel University London, Uxbridge, United Kingdom
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37
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Ochi T, Wu Q, Blundell TL. The spatial organization of non-homologous end joining: from bridging to end joining. DNA Repair (Amst) 2014; 17:98-109. [PMID: 24636752 PMCID: PMC4037875 DOI: 10.1016/j.dnarep.2014.02.010] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Revised: 01/27/2014] [Accepted: 02/10/2014] [Indexed: 01/24/2023]
Abstract
Non-homologous end joining (NHEJ) repairs DNA double-strand breaks generated by DNA damage and also those occurring in V(D)J recombination in immunoglobulin and T cell receptor production in the immune system. In NHEJ DNA-PKcs assembles with Ku heterodimer on the DNA ends at double-strand breaks, in order to bring the broken ends together and to assemble other proteins, including DNA ligase IV (LigIV), required for DNA repair. Here we focus on structural aspects of the interactions of LigIV with XRCC4, XLF, Artemis and DNA involved in the bridging and end-joining steps of NHEJ. We begin with a discussion of the role of XLF, which interacts with Ku and forms a hetero-filament with XRCC4; this likely forms a scaffold bridging the DNA ends. We then review the well-defined interaction of XRCC4 with LigIV, and discuss the possibility of this complex interrupting the filament formation, so positioning the ligase at the correct positions close to the broken ends. We also describe the interactions of LigIV with Artemis, the nuclease that prepares the ends for ligation and also interacts with DNA-PK. Lastly we review the likely affects of Mendelian mutations on these multiprotein assemblies and their impacts on the form of inherited disease.
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Affiliation(s)
- Takashi Ochi
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, UK.
| | - Qian Wu
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, UK
| | - Tom L Blundell
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, UK
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38
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Williams GJ, Hammel M, Radhakrishnan SK, Ramsden D, Lees-Miller SP, Tainer JA. Structural insights into NHEJ: building up an integrated picture of the dynamic DSB repair super complex, one component and interaction at a time. DNA Repair (Amst) 2014; 17:110-20. [PMID: 24656613 PMCID: PMC4102006 DOI: 10.1016/j.dnarep.2014.02.009] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Revised: 01/27/2014] [Accepted: 02/10/2014] [Indexed: 10/25/2022]
Abstract
Non-homologous end joining (NHEJ) is the major pathway for repair of DNA double-strand breaks (DSBs) in human cells. NHEJ is also needed for V(D)J recombination and the development of T and B cells in vertebrate immune systems, and acts in both the generation and prevention of non-homologous chromosomal translocations, a hallmark of genomic instability and many human cancers. X-ray crystal structures, cryo-electron microscopy envelopes, and small angle X-ray scattering (SAXS) solution conformations and assemblies are defining most of the core protein components for NHEJ: Ku70/Ku80 heterodimer; the DNA dependent protein kinase catalytic subunit (DNA-PKcs); the structure-specific endonuclease Artemis along with polynucleotide kinase/phosphatase (PNKP), aprataxin and PNKP related protein (APLF); the scaffolding proteins XRCC4 and XLF (XRCC4-like factor); DNA polymerases, and DNA ligase IV (Lig IV). The dynamic assembly of multi-protein NHEJ complexes at DSBs is regulated in part by protein phosphorylation. The basic steps of NHEJ have been biochemically defined to require: (1) DSB detection by the Ku heterodimer with subsequent DNA-PKcs tethering to form the DNA-PKcs-Ku-DNA complex (termed DNA-PK), (2) lesion processing, and (3) DNA end ligation by Lig IV, which functions in complex with XRCC4 and XLF. The current integration of structures by combined methods is resolving puzzles regarding the mechanisms, coordination and regulation of these three basic steps. Overall, structural results suggest the NHEJ system forms a flexing scaffold with the DNA-PKcs HEAT repeats acting as compressible macromolecular springs suitable to store and release conformational energy to apply forces to regulate NHEJ complexes and the DNA substrate for DNA end protection, processing, and ligation.
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Affiliation(s)
- Gareth J Williams
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States
| | - Michal Hammel
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States
| | - Sarvan Kumar Radhakrishnan
- Department of Biochemistry & Molecular Biology, Southern Alberta Cancer Research Institute, University of Calgary, Calgary, Alberta, T2 N 4N1 Canada
| | - Dale Ramsden
- Lineberger Comprehensive Cancer Center, Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 2759, United States
| | - Susan P Lees-Miller
- Department of Biochemistry & Molecular Biology, Southern Alberta Cancer Research Institute, University of Calgary, Calgary, Alberta, T2 N 4N1 Canada; Department of Oncology, Southern Alberta Cancer Research Institute, University of Calgary, Calgary, Alberta, T2 N 4N1 Canada.
| | - John A Tainer
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States; Department of Molecular Biology, Skaggs Institute of Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, United States.
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39
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Huber KVM, Salah E, Radic B, Gridling M, Elkins JM, Stukalov A, Jemth AS, Gokturk C, Sanjiv K, Strömberg K, Pham T, Berglund UW, Colinge J, Bennett KL, Loizou J, Helleday T, Knapp S, Superti-Furga G. Stereospecific targeting of MTH1 by (S)-crizotinib as an anticancer strategy. Nature 2014; 508:222-7. [PMID: 24695225 PMCID: PMC4150021 DOI: 10.1038/nature13194] [Citation(s) in RCA: 293] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Accepted: 03/04/2014] [Indexed: 12/21/2022]
Abstract
Activated RAS GTPase signalling is a critical driver of oncogenic transformation and malignant disease. Cellular models of RAS-dependent cancers have been used to identify experimental small molecules, such as SCH51344, but their molecular mechanism of action remains generally unknown. Here, using a chemical proteomic approach, we identify the target of SCH51344 as the human mutT homologue MTH1 (also known as NUDT1), a nucleotide pool sanitizing enzyme. Loss-of-function of MTH1 impaired growth of KRAS tumour cells, whereas MTH1 overexpression mitigated sensitivity towards SCH51344. Searching for more drug-like inhibitors, we identified the kinase inhibitor crizotinib as a nanomolar suppressor of MTH1 activity. Surprisingly, the clinically used (R)-enantiomer of the drug was inactive, whereas the (S)-enantiomer selectively inhibited MTH1 catalytic activity. Enzymatic assays, chemical proteomic profiling, kinome-wide activity surveys and MTH1 co-crystal structures of both enantiomers provide a rationale for this remarkable stereospecificity. Disruption of nucleotide pool homeostasis via MTH1 inhibition by (S)-crizotinib induced an increase in DNA single-strand breaks, activated DNA repair in human colon carcinoma cells, and effectively suppressed tumour growth in animal models. Our results propose (S)-crizotinib as an attractive chemical entity for further pre-clinical evaluation, and small-molecule inhibitors of MTH1 in general as a promising novel class of anticancer agents.
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Affiliation(s)
- Kilian V. M. Huber
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Eidarus Salah
- Nuffield Department of Clinical Medicine, Structural Genomics Consortium, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford OX3 7DQ, U.K
| | - Branka Radic
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Manuela Gridling
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Jonathan M. Elkins
- Nuffield Department of Clinical Medicine, Structural Genomics Consortium, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford OX3 7DQ, U.K
| | - Alexey Stukalov
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Ann-Sofie Jemth
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Camilla Gokturk
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Kumar Sanjiv
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Kia Strömberg
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Therese Pham
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Ulrika Warpman Berglund
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Jacques Colinge
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Keiryn L. Bennett
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Joanna Loizou
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Thomas Helleday
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Stefan Knapp
- Nuffield Department of Clinical Medicine, Structural Genomics Consortium, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford OX3 7DQ, U.K
| | - Giulio Superti-Furga
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
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40
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Gad H, Koolmeister T, Jemth AS, Eshtad S, Jacques SA, Ström CE, Svensson LM, Schultz N, Lundbäck T, Einarsdottir BO, Saleh A, Göktürk C, Baranczewski P, Svensson R, Berntsson RPA, Gustafsson R, Strömberg K, Sanjiv K, Jacques-Cordonnier MC, Desroses M, Gustavsson AL, Olofsson R, Johansson F, Homan EJ, Loseva O, Bräutigam L, Johansson L, Höglund A, Hagenkort A, Pham T, Altun M, Gaugaz FZ, Vikingsson S, Evers B, Henriksson M, Vallin KSA, Wallner OA, Hammarström LGJ, Wiita E, Almlöf I, Kalderén C, Axelsson H, Djureinovic T, Puigvert JC, Häggblad M, Jeppsson F, Martens U, Lundin C, Lundgren B, Granelli I, Jensen AJ, Artursson P, Nilsson JA, Stenmark P, Scobie M, Berglund UW, Helleday T. MTH1 inhibition eradicates cancer by preventing sanitation of the dNTP pool. Nature 2014; 508:215-21. [PMID: 24695224 DOI: 10.1038/nature13181] [Citation(s) in RCA: 365] [Impact Index Per Article: 36.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Accepted: 02/20/2014] [Indexed: 01/10/2023]
Abstract
Cancers have dysfunctional redox regulation resulting in reactive oxygen species production, damaging both DNA and free dNTPs. The MTH1 protein sanitizes oxidized dNTP pools to prevent incorporation of damaged bases during DNA replication. Although MTH1 is non-essential in normal cells, we show that cancer cells require MTH1 activity to avoid incorporation of oxidized dNTPs, resulting in DNA damage and cell death. We validate MTH1 as an anticancer target in vivo and describe small molecules TH287 and TH588 as first-in-class nudix hydrolase family inhibitors that potently and selectively engage and inhibit the MTH1 protein in cells. Protein co-crystal structures demonstrate that the inhibitors bind in the active site of MTH1. The inhibitors cause incorporation of oxidized dNTPs in cancer cells, leading to DNA damage, cytotoxicity and therapeutic responses in patient-derived mouse xenografts. This study exemplifies the non-oncogene addiction concept for anticancer treatment and validates MTH1 as being cancer phenotypic lethal.
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Affiliation(s)
- Helge Gad
- 1] Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden [2]
| | - Tobias Koolmeister
- 1] Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden [2]
| | - Ann-Sofie Jemth
- 1] Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden [2]
| | - Saeed Eshtad
- 1] Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden [2]
| | - Sylvain A Jacques
- 1] Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden [2]
| | - Cecilia E Ström
- 1] Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden [2]
| | - Linda M Svensson
- Department of Biochemistry and Biophysics, Stockholm University, S-106 91 Stockholm, Sweden
| | - Niklas Schultz
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden
| | - Thomas Lundbäck
- 1] Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden [2] Chemical Biology Consortium Sweden, Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden
| | - Berglind Osk Einarsdottir
- Sahlgrenska Translational Melanoma Group, Sahlgrenska Cancer Center, Department of Surgery, University of Gothenburg and Sahlgrenska University Hospital, S-405 30 Gothenburg, Sweden
| | - Aljona Saleh
- Department of Analytical Chemistry, Stockholm University, S-106 91 Stockholm, Sweden
| | - Camilla Göktürk
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden
| | - Pawel Baranczewski
- 1] Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden [2] Uppsala University Drug Optimization and Pharmaceutical Profiling Platform, Department of Pharmacy, Uppsala University, S-751 23 Uppsala, Sweden
| | - Richard Svensson
- 1] Chemical Biology Consortium Sweden, Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden [2] Uppsala University Drug Optimization and Pharmaceutical Profiling Platform, Department of Pharmacy, Uppsala University, S-751 23 Uppsala, Sweden
| | - Ronnie P-A Berntsson
- Department of Biochemistry and Biophysics, Stockholm University, S-106 91 Stockholm, Sweden
| | - Robert Gustafsson
- Department of Biochemistry and Biophysics, Stockholm University, S-106 91 Stockholm, Sweden
| | - Kia Strömberg
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden
| | - Kumar Sanjiv
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden
| | - Marie-Caroline Jacques-Cordonnier
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden
| | - Matthieu Desroses
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden
| | - Anna-Lena Gustavsson
- 1] Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden [2] Chemical Biology Consortium Sweden, Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden
| | - Roger Olofsson
- Sahlgrenska Translational Melanoma Group, Sahlgrenska Cancer Center, Department of Surgery, University of Gothenburg and Sahlgrenska University Hospital, S-405 30 Gothenburg, Sweden
| | - Fredrik Johansson
- Department of Genetics, Microbiology and Toxicology, Stockholm University, S-106 91 Stockholm, Sweden
| | - Evert J Homan
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden
| | - Olga Loseva
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden
| | - Lars Bräutigam
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden
| | - Lars Johansson
- 1] Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden [2] Chemical Biology Consortium Sweden, Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden
| | - Andreas Höglund
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden
| | - Anna Hagenkort
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden
| | - Therese Pham
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden
| | - Mikael Altun
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden
| | - Fabienne Z Gaugaz
- 1] Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden [2] Uppsala University Drug Optimization and Pharmaceutical Profiling Platform, Department of Pharmacy, Uppsala University, S-751 23 Uppsala, Sweden
| | - Svante Vikingsson
- 1] Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden [2] Clinical Pharmacology, Department of Medical and Health Sciences, Linköping University, S-58185 Linköping, Sweden
| | - Bastiaan Evers
- 1] Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden [2] Division of Molecular Carcinogenesis, The Netherlands Cancer Institute, 1006 Amsterdam, The Netherlands (B.E.); Department of Immunology, Genetics, and Pathology, Uppsala University, S-751 23 Uppsala, Sweden (T.D.)
| | - Martin Henriksson
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden
| | - Karl S A Vallin
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden
| | - Olov A Wallner
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden
| | - Lars G J Hammarström
- 1] Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden [2] Chemical Biology Consortium Sweden, Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden
| | - Elisee Wiita
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden
| | - Ingrid Almlöf
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden
| | - Christina Kalderén
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden
| | - Hanna Axelsson
- 1] Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden [2] Chemical Biology Consortium Sweden, Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden
| | - Tatjana Djureinovic
- 1] Department of Genetics, Microbiology and Toxicology, Stockholm University, S-106 91 Stockholm, Sweden [2] Division of Molecular Carcinogenesis, The Netherlands Cancer Institute, 1006 Amsterdam, The Netherlands (B.E.); Department of Immunology, Genetics, and Pathology, Uppsala University, S-751 23 Uppsala, Sweden (T.D.)
| | - Jordi Carreras Puigvert
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden
| | - Maria Häggblad
- Science for Life Laboratory, RNAi Cell Screening Facility, Department of Biochemistry and Biophysics, Stockholm University, S-106 91 Stockholm, Sweden
| | - Fredrik Jeppsson
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden
| | - Ulf Martens
- Science for Life Laboratory, RNAi Cell Screening Facility, Department of Biochemistry and Biophysics, Stockholm University, S-106 91 Stockholm, Sweden
| | - Cecilia Lundin
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden
| | - Bo Lundgren
- Science for Life Laboratory, RNAi Cell Screening Facility, Department of Biochemistry and Biophysics, Stockholm University, S-106 91 Stockholm, Sweden
| | - Ingrid Granelli
- Department of Analytical Chemistry, Stockholm University, S-106 91 Stockholm, Sweden
| | - Annika Jenmalm Jensen
- 1] Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden [2] Chemical Biology Consortium Sweden, Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden
| | - Per Artursson
- 1] Chemical Biology Consortium Sweden, Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden [2] Uppsala University Drug Optimization and Pharmaceutical Profiling Platform, Department of Pharmacy, Uppsala University, S-751 23 Uppsala, Sweden
| | - Jonas A Nilsson
- Sahlgrenska Translational Melanoma Group, Sahlgrenska Cancer Center, Department of Surgery, University of Gothenburg and Sahlgrenska University Hospital, S-405 30 Gothenburg, Sweden
| | - Pål Stenmark
- Department of Biochemistry and Biophysics, Stockholm University, S-106 91 Stockholm, Sweden
| | - Martin Scobie
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden
| | - Ulrika Warpman Berglund
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden
| | - Thomas Helleday
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden
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Quesne MG, Latifi R, Gonzalez-Ovalle LE, Kumar D, de Visser SP. Quantum mechanics/molecular mechanics study on the oxygen binding and substrate hydroxylation step in AlkB repair enzymes. Chemistry 2014; 20:435-46. [PMID: 24339041 PMCID: PMC3994944 DOI: 10.1002/chem.201303282] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Indexed: 01/09/2023]
Abstract
AlkB repair enzymes are important nonheme iron enzymes that catalyse the demethylation of alkylated DNA bases in humans, which is a vital reaction in the body that heals externally damaged DNA bases. Its mechanism is currently controversial and in order to resolve the catalytic mechanism of these enzymes, a quantum mechanics/molecular mechanics (QM/MM) study was performed on the demethylation of the N(1) -methyladenine fragment by AlkB repair enzymes. Firstly, the initial modelling identified the oxygen binding site of the enzyme. Secondly, the oxygen activation mechanism was investigated and a novel pathway was found, whereby the catalytically active iron(IV)-oxo intermediate in the catalytic cycle undergoes an initial isomerisation assisted by an Arg residue in the substrate binding pocket, which then brings the oxo group in close contact with the methyl group of the alkylated DNA base. This enables a subsequent rate-determining hydrogen-atom abstraction on competitive σ- and π-pathways on a quintet spin-state surface. These findings give evidence of different locations of the oxygen and substrate binding channels in the enzyme and the origin of the separation of the oxygen-bound intermediates in the catalytic cycle from substrate. Our studies are compared with small model complexes and the effect of protein and environment on the kinetics and mechanism is explained.
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Affiliation(s)
- Matthew G Quesne
- Manchester Institute of Biotechnology and School of Chemical Engineering and Analytical Science, The University of Manchester131 Princess Street, Manchester M1 7DN (UK)
| | - Reza Latifi
- Manchester Institute of Biotechnology and School of Chemical Engineering and Analytical Science, The University of Manchester131 Princess Street, Manchester M1 7DN (UK)
- Department of Chemistry, Tufts UniversityMedford MA, 02155 (USA)
| | - Luis E Gonzalez-Ovalle
- Manchester Institute of Biotechnology and School of Chemical Engineering and Analytical Science, The University of Manchester131 Princess Street, Manchester M1 7DN (UK)
| | - Devesh Kumar
- Department of Applied Physics, School of Physical Sciences, Babasaheb, Bhimrao Ambedkar UniversityVidya Vihar, Rae Bareilly Road, Lucknow 226-025 (India)
| | - Sam P de Visser
- Manchester Institute of Biotechnology and School of Chemical Engineering and Analytical Science, The University of Manchester131 Princess Street, Manchester M1 7DN (UK)
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Burgess RC, Sebesta M, Sisakova A, Marini VP, Lisby M, Damborsky J, Klein H, Rothstein R, Krejci L. The PCNA interaction protein box sequence in Rad54 is an integral part of its ATPase domain and is required for efficient DNA repair and recombination. PLoS One 2013; 8:e82630. [PMID: 24376557 PMCID: PMC3869717 DOI: 10.1371/journal.pone.0082630] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Accepted: 10/25/2013] [Indexed: 11/19/2022] Open
Abstract
Rad54 is an ATP-driven translocase involved in the genome maintenance pathway of homologous recombination (HR). Although its activity has been implicated in several steps of HR, its exact role(s) at each step are still not fully understood. We have identified a new interaction between Rad54 and the replicative DNA clamp, proliferating cell nuclear antigen (PCNA). This interaction was only mildly weakened by the mutation of two key hydrophobic residues in the highly-conserved PCNA interaction motif (PIP-box) of Rad54 (Rad54-AA). Intriguingly, the rad54-AA mutant cells displayed sensitivity to DNA damage and showed HR defects similar to the null mutant, despite retaining its ability to interact with HR proteins and to be recruited to HR foci in vivo. We therefore surmised that the PCNA interaction might be impaired in vivo and was unable to promote repair synthesis during HR. Indeed, the Rad54-AA mutant was defective in primer extension at the MAT locus as well as in vitro, but additional biochemical analysis revealed that this mutant also had diminished ATPase activity and an inability to promote D-loop formation. Further mutational analysis of the putative PIP-box uncovered that other phenotypically relevant mutants in this domain also resulted in a loss of ATPase activity. Therefore, we have found that although Rad54 interacts with PCNA, the PIP-box motif likely plays only a minor role in stabilizing the PCNA interaction, and rather, this conserved domain is probably an extension of the ATPase domain III.
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Affiliation(s)
- Rebecca C. Burgess
- Department of Genetics & Development, Columbia University Medical Center, New York, New York, United States of America
| | - Marek Sebesta
- National Centre for Biomolecular Research, Masaryk University, Brno, Czech Republic
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
- International Clinical Research Centre, Centre for Biomolecular and Cellular Engineering, Saint Anne's University Hospital, Brno, Czech Republic
| | - Alexandra Sisakova
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
- International Clinical Research Centre, Centre for Biomolecular and Cellular Engineering, Saint Anne's University Hospital, Brno, Czech Republic
| | - Victoria P. Marini
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Michael Lisby
- Department of Molecular Biology, University of Copenhagen, Copenhagen N, Denmark
| | - Jiri Damborsky
- International Clinical Research Centre, Centre for Biomolecular and Cellular Engineering, Saint Anne's University Hospital, Brno, Czech Republic
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Hannah Klein
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York, United States of America
| | - Rodney Rothstein
- Department of Genetics & Development, Columbia University Medical Center, New York, New York, United States of America
| | - Lumir Krejci
- National Centre for Biomolecular Research, Masaryk University, Brno, Czech Republic
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
- International Clinical Research Centre, Centre for Biomolecular and Cellular Engineering, Saint Anne's University Hospital, Brno, Czech Republic
- * E-mail:
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Xu SY, Kuzin AP, Seetharaman J, Gutjahr A, Chan SH, Chen Y, Xiao R, Acton TB, Montelione GT, Tong L. Structure determination and biochemical characterization of a putative HNH endonuclease from Geobacter metallireducens GS-15. PLoS One 2013; 8:e72114. [PMID: 24039739 PMCID: PMC3765158 DOI: 10.1371/journal.pone.0072114] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Accepted: 07/12/2013] [Indexed: 01/07/2023] Open
Abstract
The crystal structure of a putative HNH endonuclease, Gmet_0936 protein from Geobacter metallireducens GS-15, has been determined at 2.6 Å resolution using single-wavelength anomalous dispersion method. The structure contains a two-stranded anti-parallel β-sheet that are surrounded by two helices on each face, and reveals a Zn ion bound in each monomer, coordinated by residues Cys38, Cys41, Cys73, and Cys76, which likely plays an important structural role in stabilizing the overall conformation. Structural homologs of Gmet_0936 include Hpy99I endonuclease, phage T4 endonuclease VII, and other HNH endonucleases, with these enzymes sharing 15-20% amino acid sequence identity. An overlay of Gmet_0936 and Hpy99I structures shows that most of the secondary structure elements, catalytic residues as well as the zinc binding site (zinc ribbon) are conserved. However, Gmet_0936 lacks the N-terminal domain of Hpy99I, which mediates DNA binding as well as dimerization. Purified Gmet_0936 forms dimers in solution and a dimer of the protein is observed in the crystal, but with a different mode of dimerization as compared to Hpy99I. Gmet_0936 and its N77H variant show a weak DNA binding activity in a DNA mobility shift assay and a weak Mn²⁺-dependent nicking activity on supercoiled plasmids in low pH buffers. The preferred substrate appears to be acid and heat-treated DNA with AP sites, suggesting Gmet_0936 may be a DNA repair enzyme.
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Affiliation(s)
- Shuang-yong Xu
- New England Biolabs, Inc. Research Department, Ipswich, Massachusetts, United States of America
- * E-mail: (SX); (LT)
| | - Alexandre P. Kuzin
- Department of Biological Sciences, Northeast Structural Genomics Consortium, Columbia University, New York, New York, United States of America
| | - Jayaraman Seetharaman
- Department of Biological Sciences, Northeast Structural Genomics Consortium, Columbia University, New York, New York, United States of America
| | - Alice Gutjahr
- New England Biolabs, Inc. Research Department, Ipswich, Massachusetts, United States of America
| | - Siu-Hong Chan
- New England Biolabs, Inc. Research Department, Ipswich, Massachusetts, United States of America
| | - Yang Chen
- Department of Biological Sciences, Northeast Structural Genomics Consortium, Columbia University, New York, New York, United States of America
| | - Rong Xiao
- Center for Advanced Biotechnology and Medicine, Department of Molecular Biology and Biochemistry, Rutgers University, Department of Biochemistry, Robert Wood Johnson Medical School, Northeast Structural Genomics Consortium, Piscataway, New Jersey, United States of America
| | - Thomas B. Acton
- Center for Advanced Biotechnology and Medicine, Department of Molecular Biology and Biochemistry, Rutgers University, Department of Biochemistry, Robert Wood Johnson Medical School, Northeast Structural Genomics Consortium, Piscataway, New Jersey, United States of America
| | - Gaetano T. Montelione
- Center for Advanced Biotechnology and Medicine, Department of Molecular Biology and Biochemistry, Rutgers University, Department of Biochemistry, Robert Wood Johnson Medical School, Northeast Structural Genomics Consortium, Piscataway, New Jersey, United States of America
| | - Liang Tong
- Department of Biological Sciences, Northeast Structural Genomics Consortium, Columbia University, New York, New York, United States of America
- * E-mail: (SX); (LT)
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Lake RJ, Fan HY. Structure, function and regulation of CSB: a multi-talented gymnast. Mech Ageing Dev 2013; 134:202-11. [PMID: 23422418 DOI: 10.1016/j.mad.2013.02.004] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Revised: 01/26/2013] [Accepted: 02/08/2013] [Indexed: 11/29/2022]
Abstract
The Cockayne syndrome complementation group B protein, CSB, plays pivotal roles in transcription regulation and DNA repair. CSB belongs to the SNF2/SWI2 ATP-dependent chromatin remodeling protein family, and studies from many laboratories have revealed that CSB has multiple activities and modes of regulation. To understand the underlying mechanisms of Cockayne syndrome, it is necessary to understand how the biochemical activities of CSB are used to carry out its biological functions. In this review, we summarize our current knowledge of the structure, function and regulation of CSB, and discuss how these properties can impact the biological functions of this chromatin remodeler.
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Affiliation(s)
- Robert J Lake
- Epigenetics Program, Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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45
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Abstract
The protein Snm1B plays a key role in interstrand crosslink (ICL) repair. In a yeast two-hybrid screen we identified the protein PSF2 to bind Snm1B. PSF2 is a member of the GINS complex involved in replication initiation and elongation, and is known to play a role in ICL repair. Snm1B was shown to bind PSF2 in human cells through two regions, strongly to a 144 amino acid N-terminal region and weakly to a second smaller 37 amino acid C-terminal region. Ectopic expression of PSF2 increased the amount of Mus81, a protein component of the endonucleolytic complex involved in ICL repair, co-immunoprecipitating with Snm1B. Moreover, deleting the N-terminal, but not C-terminal region of Snm1B reduced the amount of co-immunoprecipitated Mus81. Conversely, the telomere-binding protein TRF2 competed with PSF2 for binding to the C-terminus of Snm1B, and deletion of this region, but not the N-terminal region, reduced Snm1B chromatin association. We speculate that the N-terminal region of Snm1B forms a complex containing PSF2 and Mus81, while the C-terminal region is important for PSF2-mediated chromatin association.
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Affiliation(s)
- Jay R. Stringer
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Christopher M. Counter
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina, United States of America
- * E-mail:
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46
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Iatsyshyna AP, Nidoieva ZM, Pidpala OV, Lukash LL. [Bioinformatic analysis of potential post-translational modification sites of the human O6-methylguanine-DNA methyltransferase (MGMT) protein]. Ukr Biokhim Zh (1999) 2012; 84:74-85. [PMID: 23387271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Using in silico analysis a number of potential sites for post-translational modifications has been revealed within the human O6-methylguanine-DNA methyltransferase (MGMT) protein. In particular these were the acetylation of Gly3 residue in the N-terminus of protein and internal residues Lys132 and Lys135; Arg166 residue methylation; Lys63 SUMOylation and ubiquitination of Lys31, Lys39, Lys49, Lys63, Lys67, Lys135, Lys156, Lys196, Lys209. Also it has been predicted 16 novel potential phosphorylation sites of serine residues (positions 13, 124, 144, 182, 183, 190, 215, 216 and 230), tyrosine residues (positions 100 and 189) and threonine residues (positions 23, 69, 94, 126 and 229), as well as five binding sites for kinases and other proteins (Serl3 with 14-3-3, Val21 and Ile172 with D-domain, Pro78 and Pro111 with SH3-domain, Pro111 with MAPK3). Some kinases predicted by the authors are known as partners of the MGMT protein, that confirms the probability of modification of the given sites. Potential sites require further experimental confirmation of modifications and investigation of their influence on stability and DNA-repair activity of this protein.
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47
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Falck J, Forment JV, Coates J, Mistrik M, Lukas J, Bartek J, Jackson SP. CDK targeting of NBS1 promotes DNA-end resection, replication restart and homologous recombination. EMBO Rep 2012; 13:561-8. [PMID: 22565321 PMCID: PMC3367243 DOI: 10.1038/embor.2012.58] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Revised: 03/28/2012] [Accepted: 04/13/2012] [Indexed: 12/14/2022] Open
Abstract
The conserved MRE11–RAD50–NBS1 (MRN) complex is an important sensor of DNA double-strand breaks (DSBs) and facilitates DNA repair by homologous recombination (HR) and end joining. Here, we identify NBS1 as a target of cyclin-dependent kinase (CDK) phosphorylation. We show that NBS1 serine 432 phosphorylation occurs in the S, G2 and M phases of the cell cycle and requires CDK activity. This modification stimulates MRN-dependent conversion of DSBs into structures that are substrates for repair by HR. Impairment of NBS1 phosphorylation not only negatively affects DSB repair by HR, but also prevents resumption of DNA replication after replication-fork stalling. Thus, CDK-mediated NBS1 phosphorylation defines a molecular switch that controls the choice of repair mode for DSBs.
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Affiliation(s)
- Jacob Falck
- Department of Biochemistry, Wellcome Trust and Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
- Centre for Genotoxic Stress Research, Danish Cancer Society, Strandboulevarden 49, Copenhagen DK-2100, Denmark
| | - Josep V Forment
- Department of Biochemistry, Wellcome Trust and Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
| | - Julia Coates
- Department of Biochemistry, Wellcome Trust and Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
| | - Martin Mistrik
- Centre for Genotoxic Stress Research, Danish Cancer Society, Strandboulevarden 49, Copenhagen DK-2100, Denmark
- Institute of Molecular and Translational Medicine, Palacky University, Olomouc CZ-77515, Czech Republic
| | - Jiri Lukas
- Centre for Genotoxic Stress Research, Danish Cancer Society, Strandboulevarden 49, Copenhagen DK-2100, Denmark
| | - Jiri Bartek
- Centre for Genotoxic Stress Research, Danish Cancer Society, Strandboulevarden 49, Copenhagen DK-2100, Denmark
- Institute of Molecular and Translational Medicine, Palacky University, Olomouc CZ-77515, Czech Republic
| | - Stephen P Jackson
- Department of Biochemistry, Wellcome Trust and Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
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Nakazawa Y, Sasaki K, Mitsutake N, Matsuse M, Shimada M, Nardo T, Takahashi Y, Ohyama K, Ito K, Mishima H, Nomura M, Kinoshita A, Ono S, Takenaka K, Masuyama R, Kudo T, Slor H, Utani A, Tateishi S, Yamashita S, Stefanini M, Lehmann AR, Yoshiura KI, Ogi T. Mutations in UVSSA cause UV-sensitive syndrome and impair RNA polymerase IIo processing in transcription-coupled nucleotide-excision repair. Nat Genet 2012; 44:586-92. [PMID: 22466610 DOI: 10.1038/ng.2229] [Citation(s) in RCA: 132] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2011] [Accepted: 02/29/2012] [Indexed: 01/18/2023]
Abstract
UV-sensitive syndrome (UV(S)S) is a genodermatosis characterized by cutaneous photosensitivity without skin carcinoma. Despite mild clinical features, cells from individuals with UV(S)S, like Cockayne syndrome cells, are very UV sensitive and are deficient in transcription-coupled nucleotide-excision repair (TC-NER), which removes DNA damage in actively transcribed genes. Three of the seven known UV(S)S cases carry mutations in the Cockayne syndrome genes ERCC8 or ERCC6 (also known as CSA and CSB, respectively). The remaining four individuals with UVSS , one of whom is described for the first time here, formed a separate UV(S)S-A complementation group; however, the responsible gene was unknown. Using exome sequencing, we determine that mutations in the UVSSA gene (formerly known as KIAA1530) cause UV(S)S-A. The UVSSA protein interacts with TC-NER machinery and stabilizes the ERCC6 complex; it also facilitates ubiquitination of RNA polymerase IIo stalled at DNA damage sites. Our findings provide mechanistic insights into the processing of stalled RNA polymerase and explain the different clinical features across these TC-NER–deficient disorders.
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Affiliation(s)
- Yuka Nakazawa
- Nagasaki University Research Centre for Genomic Instability and Carcinogenesis, Nagasaki, Japan
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49
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Gong H, Kovar JL, Baker B, Zhang A, Cheung L, Draney DR, Corrêa IR, Xu MQ, Olive DM. Near-infrared fluorescence imaging of mammalian cells and xenograft tumors with SNAP-tag. PLoS One 2012; 7:e34003. [PMID: 22479502 PMCID: PMC3316518 DOI: 10.1371/journal.pone.0034003] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Accepted: 02/22/2012] [Indexed: 11/19/2022] Open
Abstract
Fluorescence in the near-infrared (NIR) spectral region is suitable for in vivo imaging due to its reduced background and high penetration capability compared to visible fluorescence. SNAP(f) is a fast-labeling variant of SNAP-tag that reacts with a fluorescent dye-conjugated benzylguanine (BG) substrate, leading to covalent attachment of the fluorescent dye to the SNAP(f). This property makes SNAP(f) a valuable tool for fluorescence imaging. The NIR fluorescent substrate BG-800, a conjugate between BG and IRDye 800CW, was synthesized and characterized in this study. HEK293, MDA-MB-231 and SK-OV-3 cells stably expressing SNAP(f)-Beta-2 adrenergic receptor (SNAP(f)-ADRβ2) fusion protein were created. The ADRβ2 portion of the protein directs the localization of the protein to the cell membrane. The expression of SNAP(f)-ADRβ2 in the stable cell lines was confirmed by the reaction between BG-800 substrate and cell lysates. Microscopic examination confirmed that SNAP(f)-ADRβ2 was localized on the cell membrane. The signal intensity of the labeled cells was dependent on the BG-800 concentration. In vivo imaging study showed that BG-800 could be used to visualize xenograph tumors expressing SNAP(f)-ADRβ2. However, the background signal was relatively high, which may be a reflection of non-specific accumulation of BG-800 in the skin. To address the background issue, quenched substrates that only fluoresce upon reaction with SNAP-tag were synthesized and characterized. Although the fluorescence was successfully quenched, in vivo imaging with the quenched substrate CBG-800-PEG-QC1 failed to visualize the SNAP(f)-ADRβ2 expressing tumor, possibly due to the reduced reaction rate. Further improvement is needed to apply this system for in vivo imaging.
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Affiliation(s)
- Haibiao Gong
- LI-COR Biosciences, Lincoln, Nebraska, United States of America.
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50
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Sun J, Lee KJ, Davis AJ, Chen DJ. Human Ku70/80 protein blocks exonuclease 1-mediated DNA resection in the presence of human Mre11 or Mre11/Rad50 protein complex. J Biol Chem 2012; 287:4936-45. [PMID: 22179609 PMCID: PMC3281638 DOI: 10.1074/jbc.m111.306167] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Revised: 12/13/2011] [Indexed: 11/06/2022] Open
Abstract
DNA double strand breaks (DSB) are repaired by nonhomologous end-joining (NHEJ) or homologous recombination (HR). Recent genetic data in yeast shows that the choice between these two pathways for the repair of DSBs is via competition between the NHEJ protein, Ku, and the HR protein, Mre11/Rad50/Xrs2 (MRX) complex. To study the interrelationship between human Ku and Mre11 or Mre11/Rad50 (MR), we established an in vitro DNA end resection system using a forked model dsDNA substrate and purified human Ku70/80, Mre11, Mre11/Rad50, and exonuclease 1 (Exo1). Our study shows that the addition of Ku70/80 blocks Exo1-mediated DNA end resection of the forked dsDNA substrate. Although human Mre11 and MR bind to the forked double strand DNA, they could not compete with Ku for DNA ends or actively mediate the displacement of Ku from the DNA end either physically or via its exonuclease or endonuclease activity. Our in vitro studies show that Ku can block DNA resection and suggest that Ku must be actively displaced for DNA end processing to occur and is more complicated than the competition model established in yeast.
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Affiliation(s)
- Jingxin Sun
- From the Division of Molecular Radiation Biology, Department of Radiation Oncology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390
| | - Kyung-Jong Lee
- From the Division of Molecular Radiation Biology, Department of Radiation Oncology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390
| | - Anthony J. Davis
- From the Division of Molecular Radiation Biology, Department of Radiation Oncology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390
| | - David J. Chen
- From the Division of Molecular Radiation Biology, Department of Radiation Oncology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390
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