Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045.
Microbiol Spectr. 2019 Apr 5;7(2). doi: 10.1128/microbiolspec.GPP3-0031-2018.
is a Gram-positive opportunistic pathogen that has evolved a complex regulatory network to control virulence. One of the main functions of this interconnected network is to sense various environmental cues and respond by altering the production of virulence factors necessary for survival in the host, including cell surface adhesins and extracellular enzymes and toxins. Of these regulatory systems, one of the best studied is the accessory gene regulator (), which is a quorum-sensing system that senses the local concentration of a cyclic peptide signaling molecule. This system allows to sense its own population density and translate this information into a specific gene expression pattern. Besides , this pathogen uses other two-component systems to sense specific cues and coordinates responses with cytoplasmic regulators of the SarA protein family and alternative sigma factors. These divergent regulatory systems integrate the various environmental and host-derived signals into a network that ensures optimal pathogen response to the changing conditions. This article gives an overview of the most important and best-studied regulatory systems and summarizes the functions of these regulators during host interactions. The regulatory systems discussed include the quorum-sensing system; the SaeRS, SrrAB, and ArlRS two-component systems, the cytoplasmic SarA-family regulators (SarA, Rot, and MgrA); and the alternative sigma factors (SigB and SigH).
是一种革兰氏阳性机会致病菌，它进化出了一个复杂的调控网络来控制其毒力。这个相互关联的网络的主要功能之一是感知各种环境线索，并通过改变生存所必需的毒力因子的产生来做出反应，包括细胞表面黏附素和细胞外酶和毒素。在这些调控系统中，研究得最好的系统之一是辅助基因调控系统（），它是一种群体感应系统，可感知一种环状肽信号分子的局部浓度。该系统允许其感知自身的种群密度，并将此信息转化为特定的基因表达模式。除此之外，该病原体还使用其他两种成分系统来感知特定的线索，并与 SarA 蛋白家族的细胞质调节剂和替代 sigma 因子协调反应。这些不同的调控系统将各种环境和宿主衍生的信号整合到一个网络中，以确保病原体对不断变化的条件做出最佳反应。本文概述了最重要和研究得最好的 调控系统，并总结了这些调节剂在宿主相互作用过程中的功能。讨论的调控系统包括群体感应系统；SaeRS、SrrAB 和 ArlRS 两种成分系统、细胞质 SarA 家族调节剂（SarA、Rot 和 MgrA）；以及替代 sigma 因子（SigB 和 SigH）。
