Functional dissection of SseF, a type III effector protein involved in positioning the Salmonella-containing vacuole
Functional dissection of SseF, a type III effector protein involved in positioning the Salmonella-containing vacuole
复制标题
DOI：
10.1111/j.1600-0854.2006.00454.x
复制
发表时间：
2006-08-01
期刊：
影响因子：
4.5
通讯作者：
Hensel, Michael
中科院分区：
文献类型：
--
作者：
Abrahams, Garth L.;Mueller, Petra;Hensel, Michael
肠道沙门氏菌的细胞内复制需要形成一个独特的细胞器，称为含沙门氏菌的空泡（SCV）。由沙门氏菌致病岛2（SPI 2-T3 SS）编码的III型分泌系统（T3 SS）在SCV的形成和维持中具有关键作用。SPI 2-T3 SS易位大量干扰宿主细胞功能如微管依赖性转运的效应蛋白。我们研究了效应子SseF的功能，并观察到这种蛋白质是维持SCV在受感染上皮细胞中的非核位置所必需的。复制沙门氏菌的单核簇的形成需要向SCV募集动力蛋白，但SseF缺陷菌株向SCV募集动力蛋白的能力大大降低。我们进行了SseF的功能解剖和定义的结构域是重要的易位和这种蛋白质的特定效应功能。特别重要的是一个疏水结构域的C-末端的一半，含有三个假定的跨膜（TM）螺旋。这些TM螺旋之一的删除消融效应功能的SseF。我们观察到，这一领域是必不可少的适当的细胞内定位的SCV的一个非核，高尔基体相关的本地化。这些数据表明，SseF，与效应蛋白SifA和SseG调解的精确定位的SCV通过差异调节微管马达蛋白的募集到SCV。
Intracellular replication of Salmonella enterica requires the formation of a unique organelle termed Salmonella-containing vacuole (SCV). The type III secretion system (T3SS) encoded by Salmonella Pathogenicity Island 2 (SPI2-T3SS) has a crucial role in the formation and maintenance of the SCV. The SPI2-T3SS translocates a large number of effector proteins that interfere with host cell functions such as microtubule-dependent transport. We investigated the function of the effector SseF and observed that this protein is required to maintain the SCV in a juxtanuclear position in infected epithelial cells. The formation of juxtanuclear clusters of replicating Salmonella required the recruitment of dynein to the SCV but SseF-deficient strains were highly reduced in dynein recruitment to the SCV. We performed a functional dissection of SseF and defined domains that were important for translocation and the specific effector functions of this protein. Of particular importance was a hydrophobic domain in the C-terminal half that contains three putative transmembrane (TM) helices. Deletion of one of these TM helices ablated the effector functions of SseF. We observed that this domain was essential for the proper intracellular positioning of the SCV to a juxtanuclear, Golgi-associated localization. These data show that SseF, in concert with the effector proteins SifA and SseG mediate the precise positioning of the SCV by differentially modulating the recruitment of microtubule motor proteins to the SCV.