DNA methyltransferase Dnmt1 and mismatch repair.
We have examined the relationship between DNA mismatch repair and deficiency of DNA methylation in a mouse embryonic cell line, Dnmt1-/- ES, with homologous deletion of the gene coding for the maintenance DNA methyltransferase Dnmt1. With the use of a sensitive PCR for the assay of two mononucleotide- and three dinucleotide microsatellite markers that exhibited instabilities in mismatch repair-deficient cells, significantly higher frequencies of instability were detected at three of the five markers in Dnmt1-/- ES than the wild-type ES. The data suggest that Dnmt1 enzyme plays an integrating role in DNA replication and/or repair. The implication that Dnmt1 enzyme and/or cytosine methylation may participate in the strand discrimination of mismatch repair during eukaryotic DNA replication is discussed.
Wang
Keh-Yang
KY
Institute of Genetics, National Yang Ming University, Shih-Pai, Taipei 112, Taiwan, ROC.
James Shen
C-K
CK
D000818:Animals; D020137:Base Pair Mismatch / Q000235:genetics*; D000076123:DNA (Cytosine-5-)-Methyltransferase 1; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000172:deficiency / Q000235:genetics*; D004260:DNA Repair / Q000235:genetics*; D004261:DNA Replication / Q000235:genetics; D051379:Mice; D018345:Mice, Knockout; D018895:Microsatellite Repeats / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013234:Stem Cells
D000076123:DNA (Cytosine-5-)-Methyltransferase 1; D004248:DNA (Cytosine-5-)-Methyltransferases; C000619381:Dnmt1 protein, mouse