A complex composed of SycN and YscB functions as a specific chaperone for YopN in Yersinia pestis
A complex composed of SycN and YscB functions as a specific chaperone for YopN in Yersinia pestis
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DOI：
10.1046/j.1365-2958.1998.01110.x
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发表时间：
1998-11-01
影响因子：
3.6
通讯作者：
Plano, GV
中科院分区：
文献类型：
--
作者：
Day, JB;Plano, GV
人类致病性耶尔森氏菌抵抗宿主防御，部分是通过表达和传递一组被称为YOPs的质粒编码的毒力蛋白。当细菌与真核宿主细胞接触时，许多YOP直接从细菌输出到细胞质中。分泌的YopN蛋白(也称为LcrE)在体外或体内与真核细胞接触之前，需要在有钙存在的情况下阻止Yop的分泌。在本研究中，我们研究了tyeA、sycN和yscB基因产物在鼠疫耶尔森氏菌YOP分泌调节中的作用。TyeA、SycN或YscB表达缺失的突变体不再能够在钙存在的情况下阻断YOP的分泌。此外，在sych和yscB缺失突变体中，YopN的分泌都被特异性地减少。蛋白质交联和免疫沉淀结合酵母双杂交分析表明，SycN和YscB相互作用形成SycN/YscB复合体。酵母三杂交分析表明，与YopN特异结合的是SycN/YscB复合体，而不是SycN或YscB蛋白。SycN和YscB与Yop特异性伴侣SycE和Sych具有氨基酸序列相似性和结构相似性。综上所述，这些结果表明，在鼠疫菌中，由SycN和YscB组成的复合体是YopN的特异性伴侣。
Human pathogenic Yersinia resist host defences, in part through the expression and delivery of a set of plasmid-encoded virulence proteins termed Yops. A number of these Yops are exported from the bacteria directly into the cytoplasm of their eukaryotic host's cells upon contact with these cells. The secreted YopN protein (also known as LcrE) is required to block Yop secretion in the presence of calcium in vitro or before contact with a eukaryotic cell in vivo. In this study, we characterize the role of the tyeA, sycN and yscB gene products in the regulation of Yop secretion in Yersinia pestis. Mutants specifically defective in the expression of TyeA, SycN or YscB were no longer able to block Yop secretion in the presence of calcium. in addition, the secretion of YopN was specifically reduced in both the sycH and the yscB deletion mutants. Protein crosslinking and immunoprecipitation studies in conjunction with yeast two-hybrid analyses showed that SycN and YscB interact with one another to form a SycN/YscB complex. Yeast three-hybrid analyses demonstrated that the SycN/YscB complex, but not SycN or YscB atone, specifically associates with YopN. SycN and YscB share amino acid sequence similarity and structural similarities with the specific Yop chaperones SycE and SycH. Together, these results indicate that a complex composed of SycN and YscB functions as a specific chaperone for YopN in Y. pestis.