cagT——幽门螺杆菌cag致病岛的“底座”

cagT, the base of Helicobacter pylori cag pathogenicity island

毒素相关基因致病岛(cagPAI)是幽门螺杆菌的一个IV型分泌系统,由28～30个蛋白质组成。cagT是cagPAI的一个重要结构蛋白,位于cagPAI针尖状结构的基底部,作为此IV型分泌系统的"底座",与cagY蛋白一起构成了cagPAI的结构框架。将cagT基因敲除,则cagPAI结构消失,阻断了效应分子cagA进入宿主上皮细胞和IL-8的分泌。cagT还可与其他cagPAI蛋白质相互作用,协同转运cagA进入宿主细胞,引起宿主细胞的损伤。

Helicobacter pylon uses a type IV secretion system （T4SS） encoded by the cytotoxin-associated gene （cag） pathogenicity island （PAl） which consists of 28-30 proteins to deliver the bacterial protein cagA into gastric epithelial ceils and to induce interleukin-8 secretion. Protein cagT is one of the key structural proteins in cag PAl and locates at the base of this organelle, cagT and cagY are composed of the framework of cag PAl. No cag PAI from the bacterium is observed in AcagT mutant, cagT interacts with other cag PAl proteins. They co-translocate cagA into host cell and induce epithelial cell damage.