mismatch repair

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mis·match re·pair

replacement of mismatched base pairs by removal of the incorrect base and replacement with the correct base by DNA polymerase.

mismatch repair

An intrinsic intracellular mechanism which corrects nucleotide insertion errors made during DNA replication, by excising the mismatched base pairs that escaped correction by the proofreading activities of DNA polymerases and replacing the mismatched bases with the correct ones.

mismatch repair

a DNA REPAIR mechanism that operates to correct errors caused by MISMATCH OF BASES in newly replicated DNA. The newly synthesized DNA strand containing the incorrect BASE is cut, the base removed and the correct base inserted. In ESCHERICHIA COLI, delayed METHYLATION is used as a means of distinguishing the old (parental) DNA strand from the new (daughter) strand of the newly replicated DUPLEX. A METHYL TRANSFERASE ENZYME acts slowly after DNA REPLICATION to ensure that the daughter strand remains undermethylated, relative to the parent strand, for a while. This allows the repair system to recognize the daughter strand and replace the wrong base.
References in periodicals archive ?
coli) (MLH1), (4) DNA mismatch repair protein Msh2 (MSH2), mutS homolog 6 (MSH6), mismatch repair endonuclease PMS2 (PMS2), and epithelial cell adhesion molecule (EPCAM), such as occurs in patients with Lynch syndrome, for whom more than 90% of colon cancers test MSI positive (1, 2).
Microsatellites are short repetitive sequences of DNA; MSI, which is detected by polymerase chain reaction (PCR)-based assays that reveal the mutated microsatellites, results from impaired DNA mismatch repair (MMR) mechanisms(i.
Another autosomal-dominant disorder, hereditary nonpolyposis colorecstal cancer (HNPCC) syndrome arises as a result of a genetic defect in DNA mismatch repair mechanisms.
Moreover, it has been suggested that UEC may be linked to the group of tumors belonging to hereditary nonpolyposis colorectal carcinoma or Lynch syndrome, since a significant percentage of cases display loss of 1 or more of the DNA mismatch repair genes.
DNA mismatch repair proteins including MLH1, MSH2, MSH6 and PMS2 were all intact by immunohistochemistry.
The autosomal dominant disorder is caused by a mutation in one of four DNA mismatch repair (MMR) genes: MLH1, MSH2, MSH6, or PMS2.
HNPCC is associated with germ-line mutations in DNA mismatch repair (MMR) genes namely MLH1, MSH2, MSH6, and PMS2 (4-7).
5) MSI is associated with mutations in the DNA mismatch repair genes hMLH1 and hMSH2, and less frequently hMSH6 and PMS2, leading to the rapid development of neoplasms through the accumulation of mutations.
Cd(II) was recently shown to inhibit DNA mismatch repair (MMR) (Jin et al.
25,26) Farrington et al (24) suggested that it is necessary to analyze DNA mismatch repair genes regardless of the family history, especially in early onset CRC.
One of the two non-resistant lines and its resistant clone were deficient in their DNA mismatch repair systems, which results in genetic instability, increased susceptibility to neoplastic transformation, and greater development of chemoresistant cells.
Selection of endometrial carcinomas for DNA mismatch repair protein immunohistochemistry using patient age and tumor morphology enhances detection of mismatch repair abnormalities.