摘要
DNA复制是一个严谨有序的过程,细胞分裂时,碱基错配的概率约为1/1010～1/109。错配修复系统(MMR)是一个从细菌到真核细胞皆保守的DNA修复途径,它负责修复DNA中错配的碱基,或者DNA聚合酶的校对功能失调而引起的复制错误,插入,遗失碱基,使DNA整体复制的保真度增加50～1 000倍。MMR系统失控会导致DNA序列中微卫星序列的不稳定性(MSI)或编码功能蛋白的基因突变,改变正常细胞功能,从而引发肿瘤。
DNA replication is an extraordinarily faithful process, mutation occures at a frequency ot 1/IU＂ or 1/tu- base pairs per cell division. The MMR pathway, a DNA repair pathway conserved from bacteria to humans, targets base substitution mismatches and insertion-deletion mismatches that arise as a result of replication errors that escape the proofreading function of DNA polymerases. In doing so, MMR contributes an additional 50 ~ 1000-fold to the o- verall fidelity of replication. Thus, inactivation of MMR confers a strong mutated phenotype in which the rate of spontaneous mutation is greatly elevated, such as mierosatellite stability （ MSI）, or mutated genes that code func- tional proteins, thus give rise to cancer.
出处
《基础医学与临床》
CSCD
北大核心
2011年第12期1402-1405,共4页
Basic and Clinical Medicine
