Type: | Family | Name: | DNA mismatch repair protein Pms1/Pms2 |
Description: | There are four mammalian homologues to the bacterial mismatch repair component MutL: Pms1 (and Pms2) and Mlh1-3 []. This entry represents DNA mismatch repair protein Pms1 (post-Meiotic Segregation 1) in yeasts and plants, which is known as Pms2 in humans. The major MutL activity in eukaryotes is performed by MutL-alpha, the heterocomplex of Mlh1-Pms1 in yeast and plants, and Mlh1-Pms2 in humans [, ]. This entry also includes Pms2-like proteins (PMS2CL) []. The PMS2CL gene is a pseudogene that has significant similarity to the 3' end of Pms2. In humans, Pms2 and PMS2CL genes can undergo extensive gene conversion []. DNA repair is initiated by MutS-alpha (Msh2-Msh6) or MutS-beta (Msh2-Msh6) binding to a dsDNA mismatch, then MutL alpha is recruited to the heteroduplex. Assembly of the MutL-MutS-heteroduplex ternary complex in presence of RFC and PCNA is sufficient to activate endonuclease activity of Pms2. Pms2 introduces single-strand breaks near the mismatch and thus generates new entry points for the exonuclease Exo1 to degrade the strand containing the mismatch [, , , ]. It is also implicated in DNA damage signalling, a process which induces cell cycle arrest and can lead to apoptosis in case of major DNA damages [].Mutations in Pms2 cause Hereditary non-polyposis colorectal cancer 4 (HNPCC4) [] and Mismatch repair cancer syndrome (MMRCS) []. | Short Name: | Pms1/Pms2/PMS2L |