HNPCC mutations in the human DNA mismatch repair gene hMLH1 influence assembly of hMutLalpha and hMLH1-hEXO1 complexes.
Hereditary nonpolyposis colorectal cancer (HNPCC) is a common inherited form of neoplasia caused by germline mutations in DNA mismatch repair (MMR) genes. MMR proteins have been reported to associate with several proteins, including the human exonuclease 1 (hEXO1). We report here novel HNPCC-hMLH1 mutant proteins (T117M, Q426X and 1813insA) in Danish HNPCC patients. We demonstrate that these mutant HNPCC-hMLH1 proteins are unable to form complexes with hEXO1 and hPMS2 in vivo. The results indicate that mutations found in HNPCC gene carriers disrupt hMLH1-hEXO1 complex formation and hMutLalpha heterodimer assembly essential for MMR activity.
Jäger
A C
AC
Department of Clinical Biochemistry, Rigshospitalet, DK-2100 Copenhagen, Denmark.
Rasmussen
M
M
Bisgaard
H C
HC
Singh
K K
KK
Nielsen
F C
FC
Rasmussen
L J
LJ
D048868:Adaptor Proteins, Signal Transducing; D000251:Adenosine Triphosphatases; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D020137:Base Pair Mismatch; D002352:Carrier Proteins; D003123:Colorectal Neoplasms, Hereditary Nonpolyposis / Q000235:genetics*; D004260:DNA Repair; D045643:DNA Repair Enzymes; D004251:DNA Transposable Elements; D004268:DNA-Binding Proteins; D003718:Denmark; D004926:Escherichia coli; D029968:Escherichia coli Proteins; D005090:Exodeoxyribonucleases / Q000378:metabolism*; D006801:Humans; D000070976:Mismatch Repair Endonuclease PMS2; D008969:Molecular Sequence Data; D000070957:MutL Protein Homolog 1; D000070956:MutL Proteins; D009154:Mutation; D020125:Mutation, Missense; D009363:Neoplasm Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D009687:Nuclear Proteins; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D044465:White People
D048868:Adaptor Proteins, Signal Transducing; D001426:Bacterial Proteins; D002352:Carrier Proteins; D004251:DNA Transposable Elements; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C501486:MLH1 protein, human; C074770:MutL protein, E coli; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D011993:Recombinant Fusion Proteins; C114331:EXO1 protein, human; D005090:Exodeoxyribonucleases; C028450:exodeoxyribonuclease I; D000251:Adenosine Triphosphatases; C094934:PMS2 protein, human; D000070976:Mismatch Repair Endonuclease PMS2; D000070957:MutL Protein Homolog 1; D000070956:MutL Proteins; D045643:DNA Repair Enzymes