关键词：细菌细胞（生物学）；毒素和抗毒素；细胞凋亡
摘 要：E. coli mazEF is a stress-induced toxin-antitoxin system discovered by us as being responsible for Programmed Cell Death (PCD) in the bacteria. Recently, we showed that under condition of severe DNA damage, the triggered mazEF-mediated death pathway leads to the inhibition of an Apoptotic-Like Death (ALD) pathway mediated by recA and lexA. The well known SOS pathway is an additional cellular response to DNA damage mediated by recA-lexA. It is the largest, most complex, and best characterized bacterial network induced by DNA damage Therefore, here we asked whether the mazEF-mediated pathway also inhibits the SOS response. We found that indeed this is the case. Under mild DNA damage, the expression of mazEF inhibits the SOS response. We examined various E. coli strains commonly used for studies of the SOS response. We found that SOS response only took place in E. coli cells in which one or more elements of the E. coli toxin-antitoxin module mazEF was not functioning. Thus, the interplay between the SOS response and the mazEF mediated pathway broaden the degree of the bacterial response to DNA damage. Our work reflects the complexity of the interplays between cellular networks, and as such reflects the importance of personalized medicine.