Helmann John D
Department of Microbiology, Cornell University, Ithaca, NY 14853, USA.
Curr Opin Microbiol. 2016 Apr;30:122-132. doi: 10.1016/j.mib.2016.02.002. Epub 2016 Feb 20.
Bacillus subtilis provides a model for investigation of the bacterial cell envelope, the first line of defense against environmental threats. Extracytoplasmic function (ECF) sigma factors activate genes that confer resistance to agents that threaten the integrity of the envelope. Although their individual regulons overlap, σ(W) is most closely associated with membrane-active agents, σ(X) with cationic antimicrobial peptide resistance, and σ(V) with resistance to lysozyme. Here, I highlight the role of the σ(M) regulon, which is strongly induced by conditions that impair peptidoglycan synthesis and includes the core pathways of envelope synthesis and cell division, as well as stress-inducible alternative enzymes. Studies of these cell envelope stress responses provide insights into how bacteria acclimate to the presence of antibiotics.
枯草芽孢杆菌为研究细菌细胞包膜提供了一个模型，细胞包膜是抵御环境威胁的第一道防线。胞外功能（ECF）σ因子激活那些赋予对威胁包膜完整性的因子产生抗性的基因。尽管它们各自的调控子存在重叠，但σ（W）与膜活性剂关系最为密切，σ（X）与阳离子抗菌肽抗性相关，而σ（V）与溶菌酶抗性相关。在此，我强调σ（M）调控子的作用，它在肽聚糖合成受损的条件下被强烈诱导，包括包膜合成和细胞分裂的核心途径，以及应激诱导的替代酶。对这些细胞包膜应激反应的研究为细菌如何适应抗生素的存在提供了见解。
