Institute of Microbiology, ETH Zurich, Vladimir-Prelog-Weg 4, 8093 Zurich, Switzerland.
Institute of Microbiology, ETH Zurich, Vladimir-Prelog-Weg 4, 8093 Zurich, Switzerland.
Trends Microbiol. 2015 Mar;23(3):164-71. doi: 10.1016/j.tim.2014.12.006. Epub 2015 Jan 10.
The general stress response (GSR) is a widely conserved response that allows bacteria to cope with a multitude of stressful conditions. In the past years the PhyR-NepR-σ(EcfG) cascade was identified as the core pathway regulating the GSR in Alphaproteobacteria, in which it also plays an important role in bacteria-host interactions. The regulatory system is composed of the extracytoplasmic function sigma factor σ(EcfG), its anti-sigma factor NepR (for negative regulator of the PhyR response), and the anti-sigma factor antagonist PhyR (phyllosphere regulator). The three proteins function via a partner-switching mechanism that is triggered by PhyR phosphorylation, termed 'sigma factor mimicry'. This review will cover core features of the pathway, its physiological role, and summarize recent advances towards understanding of the partner-switching mechanism and of the two-component signaling pathways controlling the GSR.
一般应激反应（GSR）是一种广泛保守的反应，使细菌能够应对多种应激条件。在过去的几年中，PhyR-NepR-σ（EcfG）级联被确定为调节 Alphaproteobacteria 中 GSR 的核心途径，它在细菌-宿主相互作用中也起着重要作用。该调节系统由胞外功能σ因子σ（EcfG）、其反σ因子 NepR（用于 PhyR 反应的负调节剂）和反σ因子拮抗剂 PhyR（生境调节因子）组成。这三种蛋白质通过 PhyR 磷酸化触发的伴侣切换机制发挥作用，称为“σ因子模拟”。这篇综述将涵盖该途径的核心特征、其生理作用，并总结近年来对伴侣切换机制和控制 GSR 的双组分信号通路的理解的最新进展。
