Role of the SOS Response in Stationary-Phase Hypermutation: A Model for Mutation in Oncogenesis and Chemotherapeutic Drug-Resistance

摘要

The SOS response of Escherichia coli is the prototypic DNA damage repair and cell Cycle control% system, analogous to checkpoint control in eukaryotes. The SOS response includes blocking the cell cycle, global mutagenesis via more than one mechanism, and up regulation of DNA repair and recombination functions. Adaptive mutation is a mutational program in non- growing cells subjected to starvation and so is also a temporary mutagenic response to environmental stress. It entails global hypermutation, and previously, the signal transduction pathway from the environment to the DNA was unknown. Previously, we demonstrated that adaptive mutation of a lac allele in E. coli is under control of the SOS response, and that SOS induced levels of component(s) other than or in addition to RecA (hRad51 homologue) are also involved.