在大肠杆菌K12中，由甲基磺酸甲酯（MMS）诱导的GC→AT转换水平不受适应性反应的影响。

The level of GC-->AT transitions induced by MMS is not affected by the adaptive response in Escherichia coli K12.

作者信息

Sledziewska-Gójska E

机构信息

Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw.

出版信息

Mutat Res. 1993 Jun;294(1):1-8. doi: 10.1016/0921-8777(93)90052-i.

DOI:10.1016/0921-8777(93)90052-i

PMID:7683754

Abstract

I have examined the effect of the adaptive response on the frequency of MMS-induced umuC-dependent AT-->TA transversions and umuC-independent, GC-->AT transitions. It was found that the induction of the adaptive response causes a moderate decrease (50-60%) in the frequency of AT-->TA transversions and surprisingly has no effect on the level of GC-->AT transitions. In contrast, a dramatic decrease in MNNG-induced mutations has been observed in adapted cultures. However, this effect was completely abolished by MMS pretreatment of adapted cells before MNNG challenge. A mechanism for the MMS interference with the repair of MNNG-induced mutations in adapted cells is proposed.

摘要

我已经研究了适应性反应对丝裂霉素（MMS）诱导的umuC依赖性AT→TA颠换频率以及umuC非依赖性GC→AT转换频率的影响。结果发现，适应性反应的诱导会导致AT→TA颠换频率适度降低（50 - 60%），令人惊讶的是，对GC→AT转换水平没有影响。相比之下，在适应性培养物中观察到N-甲基-N'-硝基-N-亚硝基胍（MNNG）诱导的突变显著减少。然而，在MNNG攻击之前，对适应性细胞进行MMS预处理可完全消除这种效应。本文提出了一种关于MMS干扰适应性细胞中MNNG诱导突变修复的机制。