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Bruekner SR, Pieters W, Fish A, Liaci AM, Scheffers S, Rayner E, Kaldenbach D, Drost L, Dekker M, van Hees-Stuivenberg S, Delzenne-Goette E, de Konink C, Houlleberghs H, Dubbink H, AlSaegh A, de Wind N, Förster F, te Riele H, Sixma T. Unexpected moves: a conformational change in MutSα enables high-affinity DNA mismatch binding. Nucleic Acids Res 2023; 51:1173-1188. [PMID: 36715327 PMCID: PMC9943660 DOI: 10.1093/nar/gkad015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 12/30/2022] [Accepted: 01/12/2023] [Indexed: 01/31/2023] Open
Abstract
The DNA mismatch repair protein MutSα recognizes wrongly incorporated DNA bases and initiates their correction during DNA replication. Dysfunctions in mismatch repair lead to a predisposition to cancer. Here, we study the homozygous mutation V63E in MSH2 that was found in the germline of a patient with suspected constitutional mismatch repair deficiency syndrome who developed colorectal cancer before the age of 30. Characterization of the mutant in mouse models, as well as slippage and repair assays, shows a mildly pathogenic phenotype. Using cryogenic electron microscopy and surface plasmon resonance, we explored the mechanistic effect of this mutation on MutSα function. We discovered that V63E disrupts a previously unappreciated interface between the mismatch binding domains (MBDs) of MSH2 and MSH6 and leads to reduced DNA binding. Our research identifies this interface as a 'safety lock' that ensures high-affinity DNA binding to increase replication fidelity. Our mechanistic model explains the hypomorphic phenotype of the V63E patient mutation and other variants in the MBD interface.
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Affiliation(s)
| | | | - Alexander Fish
- Division of Biochemistry, Netherlands Cancer Institute and Oncode Institute, 1066 CX Amsterdam, The Netherlands
| | - A Manuel Liaci
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Utrecht University, 3584CH Utrecht, The Netherlands
| | - Serge Scheffers
- Division of Biochemistry, Netherlands Cancer Institute and Oncode Institute, 1066 CX Amsterdam, The Netherlands
| | - Emily Rayner
- Department of Human Genetics, Leiden University Medical Center, PO Box 9600 2300RC Leiden, The Netherlands
| | - Daphne Kaldenbach
- Division of Tumor Biology and Immunology, Netherlands Cancer Institute, 1066CX Amsterdam, The Netherlands
| | - Lisa Drost
- Division of Tumor Biology and Immunology, Netherlands Cancer Institute, 1066CX Amsterdam, The Netherlands
| | - Marleen Dekker
- Division of Tumor Biology and Immunology, Netherlands Cancer Institute, 1066CX Amsterdam, The Netherlands
| | | | - Elly Delzenne-Goette
- Division of Tumor Biology and Immunology, Netherlands Cancer Institute, 1066CX Amsterdam, The Netherlands
| | - Charlotte de Konink
- Division of Tumor Biology and Immunology, Netherlands Cancer Institute, 1066CX Amsterdam, The Netherlands
| | - Hellen Houlleberghs
- Division of Tumor Biology and Immunology, Netherlands Cancer Institute, 1066CX Amsterdam, The Netherlands
| | - Hendrikus Jan Dubbink
- Department of Pathology, Erasmus Medical Center, PO Box 2040 3000CA Rotterdam, The Netherlands
| | - Abeer AlSaegh
- Sultan Qaboos Comprehensive Cancer Care and Research Center, PO Box 787, 117 Muscat, Oman
| | - Niels de Wind
- Department of Human Genetics, Leiden University Medical Center, PO Box 9600 2300RC Leiden, The Netherlands
| | - Friedrich Förster
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Utrecht University, 3584CH Utrecht, The Netherlands
| | - Hein te Riele
- Correspondence may also be addressed to Hein te Riele. Tel: +31 20 512 2084;
| | - Titia K Sixma
- To whom correspondence should be addressed: Tel: +31 20 512 1959;
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Dharadhar S, van Dijk WJ, Scheffers S, Fish A, Sixma TK. Insert L1 is a central hub for allosteric regulation of USP1 activity. EMBO Rep 2021; 22:e51749. [PMID: 33619839 PMCID: PMC8024992 DOI: 10.15252/embr.202051749] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [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: 09/18/2020] [Revised: 12/22/2020] [Accepted: 01/12/2021] [Indexed: 12/14/2022] Open
Abstract
During DNA replication, the deubiquitinating enzyme USP1 limits the recruitment of translesion polymerases by removing ubiquitin marks from PCNA to allow specific regulation of the translesion synthesis (TLS) pathway. USP1 activity depends on an allosteric activator, UAF1, and this is tightly controlled. In comparison to paralogs USP12 and USP46, USP1 contains three defined inserts and lacks the second WDR20-mediated activation step. Here we show how inserts L1 and L3 together limit intrinsic USP1 activity and how this is relieved by UAF1. Intriguingly, insert L1 also conveys substrate-dependent increase in USP1 activity through DNA and PCNA interactions, in a process that is independent of UAF1-mediated activation. This study establishes insert L1 as an important regulatory hub within USP1 necessary for both substrate-mediated activity enhancement and allosteric activation upon UAF1 binding.
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Affiliation(s)
- Shreya Dharadhar
- Division of Biochemistry and Oncode InstituteNetherlands Cancer InstituteAmsterdamThe Netherlands
| | - Willem J van Dijk
- Division of Biochemistry and Oncode InstituteNetherlands Cancer InstituteAmsterdamThe Netherlands
| | - Serge Scheffers
- Division of Biochemistry and Oncode InstituteNetherlands Cancer InstituteAmsterdamThe Netherlands
| | - Alexander Fish
- Division of Biochemistry and Oncode InstituteNetherlands Cancer InstituteAmsterdamThe Netherlands
| | - Titia K Sixma
- Division of Biochemistry and Oncode InstituteNetherlands Cancer InstituteAmsterdamThe Netherlands
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