Feng Xiuhong, Oropeza Ricardo, Kenney Linda J
Department of Molecular Microbiology and Immunology, L-220, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239-3098, USA.
Mol Microbiol. 2003 May;48(4):1131-43. doi: 10.1046/j.1365-2958.2003.03502.x.
Expression of genes located on Salmonella pathogenicity island 2 (SPI-2) is required for systemic infection in mice. This region encodes a type III secretion system, secreted effectors and the two-component regulatory system SsrA/B (also referred to as SpiR), as well as additional uncharacterized genes. In the present work, we demonstrate that phospho-OmpR (OmpR-P) functions as an activator at the spiC-ssrA/B locus. There are two promoters at spiR; one is upstream of ssrA and the other upstream of ssrB. Our results indicate that, in contrast to many two-component regulatory systems, regulation of the sensor kinase SsrA appears to be uncoupled and distinct from regulation of the response regulator SsrB. OmpR regulation of ssrA/B is one of only a few examples known in which a two-component response regulator directly regulates the expression of another two-component regulatory system.
位于沙门氏菌致病岛2（SPI-2）上的基因表达是小鼠全身感染所必需的。该区域编码一个III型分泌系统、分泌效应蛋白以及双组分调节系统SsrA/B（也称为SpiR），还有其他未鉴定的基因。在本研究中，我们证明磷酸化的OmpR（OmpR-P）在spiC-ssrA/B位点起激活剂的作用。spiR有两个启动子；一个在ssrA上游，另一个在ssrB上游。我们的结果表明，与许多双组分调节系统不同，传感激酶SsrA的调节似乎与反应调节因子SsrB的调节解偶联且不同。OmpR对ssrA/B的调节是已知的少数几个双组分反应调节因子直接调节另一个双组分调节系统表达的例子之一。
