YscB of Yersinia pestis functions as a specific chaperone for YopN
YscB of Yersinia pestis functions as a specific chaperone for YopN
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DOI：
10.1128/jb.180.18.4912-4921.1998
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发表时间：
1998-09-01
影响因子：
3.2
通讯作者：
Plano, GV
中科院分区：
文献类型：
--
作者：
Jackson, MW;Day, JB;Plano, GV
在与真核细胞接触后，对人类致病的耶尔森氏菌（Y.鼠疫菌、假结核菌和Y.小肠结肠炎菌（enterocolitica）将一组不同的毒力蛋白（YopE、YopH、YopJ、YopM和YpkA）从细菌输出并易位到真核细胞中。在37 ° C下在钙存在下的体外生长期间，Yop分泌被阻断;然而，在钙不存在下，Yop分泌被触发。Yop分泌通过质粒编码的III型或“接触依赖性”分泌系统发生。分泌的YopN（也称为LcrE）、TyeA和LcrG蛋白是在钙存在下和在与真核细胞接触之前防止Yop分泌所必需的。在本文中，我们描述了yscB基因产物在Y中Yop分泌调节中的作用。鼠疫一个yscB缺失突变体分泌的YopM和V抗原的存在和不存在的钙，然而，出口的YopN是专门减少在这个菌株。与反式yscB的功能拷贝互补完全恢复了YopM、YopN和V抗原的野生型分泌表型。YscB的氨基酸序列与SycE和SycH（分别为YopE和YopH的特异性Yop分子伴侣）的氨基酸序列具有显著的相似性。蛋白质交联和免疫沉淀研究表明，YscB和YopN之间的特定相互作用。在yopN中消除氨基酸51至85或6至100的编码区的框内缺失阻止了YopN与YscB的相互作用。综上所述，这些结果表明YscB在Y中作为YopN的特异性伴侣发挥作用。鼠疫
Following contact with a eucaryotic cell, Yersinia species pathogenic for humans (Y. pestis, Y, pseudotuberculosis, and Y. enterocolitica) export and translocate a distinct set of virulence proteins (YopE, YopH, YopJ, YopM, and YpkA) from the bacterium into the eucaryotic cell. During in vitro growth at 37 degrees C in the presence of calcium, Yop secretion is blocked; however, in the absence of calcium, Yop secretion is triggered. Yop secretion occurs via a plasmid-encoded type III, or "contact-dependent" secretion system. The secreted YopN (also known as LcrE), TyeA, and LcrG proteins are necessary to prevent Yop secretion in the presence of calcium and prior to contact with a eucaryotic cell. In this paper we characterize the role of the yscB gene product in the regulation of Yop secretion in Y. pestis. A yscB deletion mutant secreted YopM and V antigen both in the presence and in the absence of calcium; however, the export of YopN was specifically reduced in this strain. Complementation with a functional copy of yscB in trans completely restored the wild-type secretion phenotype for YopM, YopN, and V antigen. The YscB amino acid sequence showed significant similarities to those of SycE and SycH, the specific Yop chaperones for YopE and YopH, respectively. Protein cross-linking and immunoprecipitation studies demonstrated a specific interaction between YscB and YopN. In-frame deletions in yopN eliminating the coding region for amino acids 51 to 85 or 6 to 100 prevented the interaction of YopN with YscB. Taken together, these results indicate that YscB functions as a specific chaperone for YopN in Y. pestis.