Evidence for involvement of yeast proliferating cell nuclear antigen in DNA mismatch repair.
DNA mismatch repair plays a key role in the maintenance of genetic fidelity. Mutations in the human mismatch repair genes hMSH2, hMLH1, hPMS1, and hPMS2 are associated with hereditary nonpolyposis colorectal cancer. The proliferating cell nuclear antigen (PCNA) is essential for DNA replication, where it acts as a processivity factor. Here, we identify a point mutation, pol30-104, in the Saccharomyces cerevisiae POL30 gene encoding PCNA that increases the rate of instability of simple repetitive DNA sequences and raises the rate of spontaneous forward mutation. Epistasis analyses with mutations in mismatch repair genes MSH2, MLH1, and PMS1 suggest that the pol30-104 mutation impairs MSH2/MLH1/PMS1-dependent mismatch repair, consistent with the hypothesis that PCNA functions in mismatch repair. MSH2 functions in mismatch repair with either MSH3 or MSH6, and the MSH2-MSH3 and MSH2-MSH6 heterodimers have a role in the recognition of DNA mismatches. Consistent with the genetic data, we find specific interaction of PCNA with the MSH2-MSH3 heterodimer.
Johnson
R E
RE
Sealy Center for Molecular Science, University of Texas Medical Branch, Galveston, Texas 77555-1061, USA.
Kovvali
G K
GK
Guzder
S N
SN
Amin
N S
NS
Holm
C
C
Habraken
Y
Y
Sung
P
P
Prakash
L
L
Prakash
S
S
D048868:Adaptor Proteins, Signal Transducing; D000251:Adenosine Triphosphatases; D002352:Carrier Proteins; D004260:DNA Repair; D045643:DNA Repair Enzymes; D004268:DNA-Binding Proteins / Q000378:metabolism; D005656:Fungal Proteins / Q000378:metabolism; D005800:Genes, Fungal; D006801:Humans; D000070976:Mismatch Repair Endonuclease PMS2; D000070957:MutL Protein Homolog 1; D000070956:MutL Proteins; D051718:MutS Homolog 2 Protein; D009363:Neoplasm Proteins; D017354:Point Mutation; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins
D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C088859:MLH1 protein, S cerevisiae; D009363:Neoplasm Proteins; C088858:PMS1 protein, S cerevisiae; C088996:PMS1 protein, human; D018809:Proliferating Cell Nuclear Antigen; D011506:Proteins; D029701:Saccharomyces cerevisiae Proteins; D000251:Adenosine Triphosphatases; C094934:PMS2 protein, human; C489751:MSH2 protein, S cerevisiae; D000070976:Mismatch Repair Endonuclease PMS2; D000070957:MutL Protein Homolog 1; D000070956:MutL Proteins; D051718:MutS Homolog 2 Protein; D045643:DNA Repair Enzymes