Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea.
J Bacteriol. 2012 Mar;194(5):982-92. doi: 10.1128/JB.06396-11. Epub 2011 Dec 16.
Burkholderia glumae possesses a quorum-sensing (QS) system mediated by N-octanoyl-homoserine lactone (C(8)-HSL) and its cognate receptor TofR. TofR/C(8)-HSL regulates the expression of a transcriptional regulator, qsmR. We identified one of the universal stress proteins (Usps), Usp2, from a genome-wide analysis of QS-dependent proteomes of B. glumae. In the whole genome of B. glumae BGR1, 11 usp genes (usp1 to usp11) were identified. Among the stress conditions tested, usp1 and usp2 mutants died 1 h after heat shock stress, whereas the other usp mutants and the wild-type strain survived for more than 3 h at 45°C. The expressions of all usp genes were positively regulated by QS, directly by QsmR. In addition, the expressions of usp1 and usp2 were dependent on RpoS in the stationary phase, as confirmed by the direct binding of RpoS-RNA holoenzyme to the promoter regions of the usp1 and usp2 genes. The expression of usp1 was upregulated upon a temperature shift from 37°C to either 28°C or 45°C, whereas the expression of usp2 was independent of temperature stress. This indicates that the regulation of usp1 and usp2 expression is different from what is known about Escherichia coli. Compared to the diverse roles of Usps in E. coli, Usps in B. glumae are dedicated to heat shock stress.
腐生伯克霍尔德氏菌拥有一个群体感应（QS）系统，由 N-辛酰基高丝氨酸内酯（C8-HSL）及其同源受体 TofR 介导。TofR/C8-HSL 调节转录调节因子 qsmR 的表达。我们从腐生伯克霍尔德氏菌的 QS 依赖的蛋白质组的全基因组分析中鉴定了一种普遍应激蛋白（Usps），Usp2。在腐生伯克霍尔德氏菌 BGR1 的整个基因组中，鉴定出 11 个 usp 基因（usp1 到 usp11）。在测试的应激条件下，usp1 和 usp2 突变体在热激应激后 1 小时死亡，而其他 usp 突变体和野生型菌株在 45°C 下存活超过 3 小时。所有 usp 基因的表达均受 QS 直接由 QsmR 正向调控。此外，usp1 和 usp2 的表达在静止期依赖于 RpoS，这通过 RpoS-RNA 全酶直接结合到 usp1 和 usp2 基因的启动子区域得到证实。usp1 的表达在从 37°C 到 28°C 或 45°C 的温度转换时上调，而 usp2 的表达不受温度应激的影响。这表明 usp1 和 usp2 表达的调节不同于已知的大肠杆菌。与大肠杆菌中 Usps 的多种作用相比，腐生伯克霍尔德氏菌中的 Usps 专门用于热激应激。
