Manganelli Riccardo, Gennaro Maria Laura
Department of Molecular Medicine, University of Padova, 35121 Padova, Italy.
Public Health Research Institute, New Jersey Medical School, Rutgers University, Newark, New Jersey 07103, USA.
Trends Microbiol. 2017 Mar;25(3):205-216. doi: 10.1016/j.tim.2016.10.001. Epub 2016 Nov 16.
During envelope stress, critical inner-membrane functions are preserved by the phage-shock-protein (Psp) system, a stress response that emerged from work with Escherichia coli and other Gram-negative bacteria. Reciprocal regulatory interactions and multiple effector functions are well documented in these organisms. Searches for the Psp system across phyla reveal conservation of only one protein, PspA. However, examination of Firmicutes and Actinobacteria reveals that PspA orthologs associate with non-orthologous regulatory and effector proteins retaining functions similar to those in Gram-negative counterparts. Conservation across phyla emphasizes the long-standing importance of the Psp system in prokaryotes, while inter- and intra-phyla variations within the system indicate adaptation to different cell envelope structures, bacterial lifestyles, and/or bacterial morphogenetic strategies.
在包膜应激期间，噬菌体休克蛋白（Psp）系统可维持关键内膜功能，这是一种源于对大肠杆菌和其他革兰氏阴性菌研究的应激反应。在这些生物体中，相互的调节相互作用和多种效应功能已有充分记录。对各门类中Psp系统的搜索发现，只有一种蛋白质PspA具有保守性。然而，对厚壁菌门和放线菌门的研究表明，PspA直系同源物与非直系同源的调节蛋白和效应蛋白相关联，这些蛋白保留了与革兰氏阴性菌对应物相似的功能。跨门类的保守性强调了Psp系统在原核生物中长期以来的重要性，而该系统在门类间和门类内的变异表明其适应了不同的细胞包膜结构、细菌生活方式和/或细菌形态发生策略。
