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Functional analysis of HNPCC-related missense mutations in MSH2.
Mutat Res. 2008 Oct 14; 645(1-2):44-55.MR

Abstract

Hereditary nonpolyposis colorectal cancer (HNPCC) is associated with germline mutations in the human DNA mismatch repair (MMR) genes, most frequently MSH2 and MLH1. The majority of HNPCC mutations cause truncations and thus loss of function of the affected polypeptide. However, a significant proportion of MMR mutations found in HNPCC patients are single amino acid substitutions and the functional consequences of many of these mutations in DNA repair are unclear. We have examined the consequences of seven MSH2 missense mutations found in HNPCC families by testing the MSH2 mutant proteins in functional assays as well as by generating equivalent missense mutations in Escherichia coli MutS and analyzing the phenotypes of these mutants. Here we show that two mutant proteins, MSH2-P622L and MSH2-C697F confer multiple biochemical defects, namely in mismatch binding, in vivo interaction with MSH6 and EXO1, and in nuclear localization in the cell. Mutation G674R, located in the ATP-binding region of MSH2, appears to confer resistance to ATP-dependent mismatch release. Mutations D167H and H639R show reduced mismatch binding. Results of in vivo experiments in E. coli with MutS mutants show that one additional mutant, equivalent of MSH2-A834T that do not show any defects in MSH2 assays, is repair deficient. In conclusion, all mutant proteins (except for MSH2-A305T) have defects; either in mismatch binding, ATP-release, mismatch repair activity, subcellular localization or protein-protein interactions.

Authors+Show Affiliations

Department of Science, Systems and Models, Roskilde University, Roskilde, Denmark.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

18822302

Citation

Lützen, Anne, et al. "Functional Analysis of HNPCC-related Missense Mutations in MSH2." Mutation Research, vol. 645, no. 1-2, 2008, pp. 44-55.
Lützen A, de Wind N, Georgijevic D, et al. Functional analysis of HNPCC-related missense mutations in MSH2. Mutat Res. 2008;645(1-2):44-55.
Lützen, A., de Wind, N., Georgijevic, D., Nielsen, F. C., & Rasmussen, L. J. (2008). Functional analysis of HNPCC-related missense mutations in MSH2. Mutation Research, 645(1-2), 44-55. https://doi.org/10.1016/j.mrfmmm.2008.08.015
Lützen A, et al. Functional Analysis of HNPCC-related Missense Mutations in MSH2. Mutat Res. 2008 Oct 14;645(1-2):44-55. PubMed PMID: 18822302.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Functional analysis of HNPCC-related missense mutations in MSH2. AU - Lützen,Anne, AU - de Wind,Niels, AU - Georgijevic,Dubravka, AU - Nielsen,Finn Cilius, AU - Rasmussen,Lene Juel, Y1 - 2008/09/04/ PY - 2008/03/05/received PY - 2008/07/25/revised PY - 2008/08/26/accepted PY - 2008/9/30/pubmed PY - 2009/1/7/medline PY - 2008/9/30/entrez SP - 44 EP - 55 JF - Mutation research JO - Mutat. Res. VL - 645 IS - 1-2 N2 - Hereditary nonpolyposis colorectal cancer (HNPCC) is associated with germline mutations in the human DNA mismatch repair (MMR) genes, most frequently MSH2 and MLH1. The majority of HNPCC mutations cause truncations and thus loss of function of the affected polypeptide. However, a significant proportion of MMR mutations found in HNPCC patients are single amino acid substitutions and the functional consequences of many of these mutations in DNA repair are unclear. We have examined the consequences of seven MSH2 missense mutations found in HNPCC families by testing the MSH2 mutant proteins in functional assays as well as by generating equivalent missense mutations in Escherichia coli MutS and analyzing the phenotypes of these mutants. Here we show that two mutant proteins, MSH2-P622L and MSH2-C697F confer multiple biochemical defects, namely in mismatch binding, in vivo interaction with MSH6 and EXO1, and in nuclear localization in the cell. Mutation G674R, located in the ATP-binding region of MSH2, appears to confer resistance to ATP-dependent mismatch release. Mutations D167H and H639R show reduced mismatch binding. Results of in vivo experiments in E. coli with MutS mutants show that one additional mutant, equivalent of MSH2-A834T that do not show any defects in MSH2 assays, is repair deficient. In conclusion, all mutant proteins (except for MSH2-A305T) have defects; either in mismatch binding, ATP-release, mismatch repair activity, subcellular localization or protein-protein interactions. SN - 0027-5107 UR - https://www.unboundmedicine.com/medline/citation/18822302/Functional_analysis_of_HNPCC_related_missense_mutations_in_MSH2_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0027-5107(08)00189-9 DB - PRIME DP - Unbound Medicine ER -