Department of Plant Pathology, College of Agronomy & Biotechnology, China Agricultural University, Bejing, China.
Mol Plant Microbe Interact. 2010 Jul;23(7):871-8. doi: 10.1094/MPMI-23-7-0871.
The type III secretion system (T3SS) is considered one of the major virulence factors in many bacterial pathogens. This report demonstrates that RssB, ClpXP, and RpoS play a role in T3SS regulation of Dickeya dadantii 3937. ClpP is a serine-type protease which associates with the ClpX chaperone to form a functional Clp proteolytic complex for degradation of proteins. With the assistance of recognition factor RssB, ClpXP degrades the RpoS sigma factor. RpoS positively regulates the expression of the rsmA gene encoding an RNA-binding regulatory protein. By interacting with the hrpL mRNA, RsmA reduces HrpL production and downregulates the T3SS genes in the HrpL regulon. In addition, ClpXP, RssB, and RpoS affect pectinolytic enzyme production in D. dadantii 3937, probably through RsmA. The ClpXP and RssB proteins are essential for bacterial virulence.
III 型分泌系统（T3SS）被认为是许多细菌病原体的主要毒力因子之一。本报告表明，RssB、ClpXP 和 RpoS 在 Dickeya dadantii 3937 的 T3SS 调控中发挥作用。ClpP 是一种丝氨酸型蛋白酶，与 ClpX 伴侣蛋白结合形成功能性 Clp 蛋白水解复合物，用于降解蛋白质。在识别因子 RssB 的协助下，ClpXP 降解 RpoS σ 因子。RpoS 正向调控编码 RNA 结合调节蛋白的 rsmA 基因的表达。通过与 hrpL mRNA 相互作用，RsmA 减少 HrpL 的产生并下调 HrpL 调控子中的 T3SS 基因。此外，ClpXP、RssB 和 RpoS 可能通过 RsmA 影响 D. dadantii 3937 中的果胶酶产生。ClpXP 和 RssB 蛋白对细菌毒力至关重要。
