Iriarte M, Cornelis G R
Microbial Pathogenesis Unit, Christian de Duve Institute of Cellular Pathology, and Faculté de Médecine, Université Catholique de Louvain, Brussels, Belgium.
Mol Microbiol. 1998 Aug;29(3):915-29. doi: 10.1046/j.1365-2958.1998.00992.x.
Extracellular Yersinia disarm the immune system of their host by injecting effector Yop proteins into the cytosol of target cells. Five effectors have been described: YopE, YopH, YpkA/YopO, YopP and YopM. Delivery of these effectors by Yersinia adhering at the cell surface requires other Yops (translocators) including YopB. Effector and translocator Yops are secreted by the type III Ysc secretion apparatus, and some Yops also need a specific cytosolic chaperone, called Syc. In this paper, we describe a new Yop, which we have called YopT (35.5kDa). Its secretion required an intact Ysc apparatus and SycT (15.0kDa, pl4.4), a new chaperone resembling SycE. Infection of macrophages with a Yersinia, producing a hybrid YopT-adenylate cyclase, led to the accumulation of intracellular cAMP, indicating that YopT is delivered into the cytosol of eukaryotic cells. Infection of HeLa cells with a mutant strain devoid of the five known Yop effectors (deltaHOPEM strain) but producing YopT resulted in the alteration of the cell cytoskeleton and the disruption of the actin filament structure. This cytotoxic effect was caused by YopT and dependent on YopB. YopT is thus a new effector Yop and a new bacterial toxin affecting the cytoskeleton of eukaryotic cells.
胞外耶尔森菌通过将效应蛋白Yop注入靶细胞胞质溶胶来解除宿主的免疫系统。已描述了五种效应蛋白：YopE、YopH、YpkA/YopO、YopP和YopM。耶尔森菌在细胞表面黏附时输送这些效应蛋白需要其他Yop蛋白（转运蛋白），包括YopB。效应蛋白和转运蛋白Yop由III型Ysc分泌装置分泌，一些Yop蛋白还需要一种特定的胞质伴侣蛋白，称为Syc。在本文中，我们描述了一种新的Yop蛋白，我们将其称为YopT（35.5 kDa）。它的分泌需要完整的Ysc装置和SycT（15.0 kDa，pI 4.4），一种类似于SycE的新伴侣蛋白。用产生杂交YopT-腺苷酸环化酶的耶尔森菌感染巨噬细胞，导致细胞内cAMP积累，表明YopT被输送到真核细胞的胞质溶胶中。用缺乏五种已知Yop效应蛋白的突变菌株（deltaHOPEM菌株）但产生YopT感染HeLa细胞，导致细胞骨架改变和肌动蛋白丝结构破坏。这种细胞毒性作用是由YopT引起的，并且依赖于YopB。因此，YopT是一种新的效应蛋白Yop，也是一种影响真核细胞骨架的新型细菌毒素。
