Salmonella Pathogenicity Island 4 encodes a giant non-fimbrial adhesin and the cognate type 1 secretion system
Salmonella Pathogenicity Island 4 encodes a giant non-fimbrial adhesin and the cognate type 1 secretion system
复制标题
DOI：
10.1111/j.1462-5822.2007.00919.x
复制
发表时间：
2007-07-01
影响因子：
3.4
通讯作者：
Hensel, Michael
中科院分区：
文献类型：
--
作者：
Gerlach, Roman G.;Jaeckel, Daniela;Hensel, Michael
致病岛在肠道沙门氏菌感染的发病机制中起主要作用。沙门氏菌致病岛4（SPI4）的分子功能在很大程度上是未知的，但最近的工作表明，在某些动物模型中，SPI4的沙门氏菌发病机制的作用。我们分析了SPI4的毒力功能，并观察到SPI4有助于小鼠模型中的肠道炎症。在细胞水平上，SPI4介导对上皮细胞的粘附。我们证明了SPI4编码的蛋白作为I型分泌系统（T1SS）的功能，并确定SiiE作为T1SS的底物蛋白。SiiE分泌到培养基中，但介导与上皮细胞表面的接触依赖性粘附。SiiE是600 kDa的非常大的非菌毛粘附素，由53个重复的IG结构域组成。我们的研究描述了第一个T1SS分泌的蛋白质，作为非菌毛粘附素结合真核细胞。SPI4编码的T1SS和SiiE可能在功能上类似于I型菌毛粘附素。
Pathogenicity Islands play a major role in the pathogenesis of infections by Salmonella enterica. The molecular function of Salmonella Pathogenicity Island 4 (SPI4) is largely unknown, but recent work indicated a role of SPI4 for Salmonella pathogenesis in certain animal models. We analysed the virulence functions of SPI4 and observed that SPI4 is contributing to intestinal inflammation in a mouse model. On a cellular level, SPI4 mediates adhesion to epithelial cells. We demonstrate the function of SPI4-encoded proteins as a type I secretion system (T1SS) and identify SiiE as the substrate protein of the T1SS. SiiE is secreted into the culture medium but mediates contact-dependent adhesion to epithelial cell surfaces. SiiE is a very large non-fimbrial adhesin of 600 kDa and consists of 53 repeats of Ig domains. Our study describes the first T1SS-secreted protein that functions as a non-fimbrial adhesin in binding to eukaryotic cells. The SPI4-encoded T1SS and SiiE might functionally resemble the type I fimbrial adhesins.