中文摘要：

目的研究沙门菌感染宿主细胞的过程中，沙门菌Ⅲ型分泌系统分泌的效应蛋白SopB对宿主细胞蛋白激酶MAPK的激活作用，同时寻找SopB蛋白与MAPK激活有关的结构域。方法通过基因克隆的方法将沙门菌SopB全长基因以及各种SopBtruncation均被克隆至pCS2一EGFP质粒载体中，利用磷酸钙转染法将该SopB重组质粒转染至HeLa细胞，24h后通过westemblot方法利用磷酸化的pERK1／2、p-p38以及pJNK抗体检测HeLa细胞MAPK蛋白激酶受SopB激活的情况。结果在HeLa细胞中过量表达SODB蛋白能够显著诱导蛋白激酶MAPK的磷酸化激活，进一步在HeLa细胞中表达SopB各种truncation片段证实，SopB对HeLa细胞MAPK蛋白激酶的激活与其N末端29个氨基酸直接相关。结论SopB可以激活宿主细胞MAPK信号途径，且这种活性与其N末端29个氨基酸有关。

英文摘要：

Objective To investigate the phosphorylation of MAPKs in host cells during Salmonella infection activated by SopB, an effector delivered by the Salmonella type III secretion systems （T3SS） and to discover the domain of SopB responsible for the activition. Methods The full length and various truncations of SopB gene were cloned into the mammals vector pCS2-EGFE an plasmid expressing an fusion protein of Green fluorescent protein （GFP）. After the recombinant SopB plasmid was transfected into HeLa cells with calcium phosphate for 24 hours, the level of phosphorylated MAPKs in HeLa cells were observed by western blot with anti-pErk, anti p-p38 and anti p-JNK antibodies. Results Overexpressing the SopB obviously activated the phosphorylation of MAPKs in HeLa cells, but not its phosphoinositide phosphatase activity mutant of C460S. And the results from SopB truncations demonstrated that the 29 amino acid at the head of SopB N terminal was critical to activation of MAPKs in HeLa cells with the unknown mechanism. Conelusion SopB activates MAPK signaling pathway in host cells, and the activity is correlated with the 29 amino acid at the head of SopB.N terminal.