Fass Ephraim, Groisman Eduardo A
Department of Molecular Microbiology, Howard Hughes Medical Institute, Washington University School of Medicine, St. Louis, MO 63110, USA.
Curr Opin Microbiol. 2009 Apr;12(2):199-204. doi: 10.1016/j.mib.2009.01.004. Epub 2009 Mar 4.
The Salmonella Pathogenicity Island-2 (i.e. SPI-2) encodes a unique type III secretion system that delivers effector proteins from the Salmonella-containing vacuole (SCV) into the host cell. The SPI-2 locus also encodes translocated effectors as well as a two-component system - termed SpiR/SsrB - that is essential for the expression of SPI-2 genes. Transcription of the horizontally acquired SPI-2 genes requires the ancestral nucleoid-associated proteins (i.e. NAPs) IHF and Fis, the regulatory protein SlyA, and the two-component systems PhoP/PhoQ and OmpR/EnvZ, as well as the DNA binding protein HilD encoded in a different pathogenicity island. Some of these positive SPI-2 regulators act to antagonize the robust silencing promoted by the NAPs H-NS, Hha, and YdgT.
沙门氏菌致病岛2(即SPI-2)编码一种独特的III型分泌系统,该系统将效应蛋白从含沙门氏菌液泡(SCV)转运至宿主细胞。SPI-2基因座还编码转运效应蛋白以及一个双组分系统——称为SpiR/SsrB——它对SPI-2基因的表达至关重要。水平获得的SPI-2基因的转录需要祖先类核相关蛋白(即NAPs)IHF和Fis、调节蛋白SlyA、双组分系统PhoP/PhoQ和OmpR/EnvZ,以及编码在不同致病岛中的DNA结合蛋白HilD。这些SPI-2阳性调节因子中的一些可拮抗由NAPs H-NS、Hha和YdgT促进的强大沉默作用。