Salmonella-directed recruitment of new membrane to invasion foci via the host exocyst complex.
Salmonella-directed recruitment of new membrane to invasion foci via the host exocyst complex.
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DOI：
10.1016/j.cub.2010.05.065
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发表时间：
2010-07-27
期刊：
影响因子：
9.2
通讯作者：
Casanova, James E.
中科院分区：
文献类型：
--
作者：
Nichols, Christina D.;Casanova, James E.
沙门氏菌附着于肠上皮触发细菌效应蛋白通过III型分泌系统（T3 SS）递送到宿主细胞溶质中，导致明显的膜皱褶和附着细菌的巨胞饮摄取。T3 SS的尖端由两种蛋白质SipB和SipC组成，它们插入宿主质膜形成易位孔。SipC的N-和C-末端都暴露在宿主胞质溶胶中，并已显示直接调节肌动蛋白细胞骨架组装。我们已经确定了SipC和Exo 70之间的直接相互作用，Exo 70是外囊复合物的一个组分，其介导外囊泡与质膜的对接和融合。在这里，我们表明，外囊成分与SipC共沉淀，并在鼠伤寒沙门氏菌的入侵部位积累。外囊装配需要激活的小GTdR的RalA，我们发现这是在沙门氏菌感染期间由易位效应，SopE触发。RalA或Sec 5的敲低导致附着位点处的膜皱褶减少，并损害细菌进入宿主细胞。这些结果表明，S。鼠伤寒沙门氏菌通过促进局部膜扩张来增强侵袭效率，直接通过SipC依赖性的外囊募集，间接通过SopE依赖性的RalA激活。
Salmonella attachment to the intestinal epithelium triggers delivery of bacterial effector proteins into the host cytosol through a Type III Secretion System (T3SS), leading to pronounced membrane ruffling and macropinocytic uptake of attached bacteria. The tip of the T3SS is comprised of two proteins, SipB and SipC, which insert into the host plasma membrane forming a translocation pore. Both the N- and C-termini of SipC are exposed in the host cytosol and have been shown to directly modulate actin cytoskeleton assembly. We have identified a direct interaction between SipC and Exo70, a component of the exocyst complex, which mediates docking and fusion of exocytic vesicles with the plasma membrane. Here we show that exocyst components co-precipitate with SipC and accumulate at sites of invasion by Salmonella typhimurium. Exocyst assembly requires activation of the small GTPase RalA, which we show is triggered during Salmonella infection by the translocated effector, SopE. Knockdown of RalA or Sec5 results in reduced membrane ruffling at sites of attachment and impairs bacterial entry into host cells. These findings suggest that S. typhimurium enhances invasion efficiency by promoting localized membrane expansion, directly through SipC-dependent recruitment of the exocyst and indirectly via SopE-dependent activation of RalA.
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影响因子：
6.7
作者：
Mounier, Joelle;Popoff, Michel R.;Enninga, Jost;Frame, Margaret C.;Sansonetti, Philippe J.;Van Nhieu, Guy Tran
通讯作者：
Van Nhieu, Guy Tran
DOI：
10.1523/jneurosci.3907-09.2009
发表时间：
2009-10-21
期刊：
The Journal of neuroscience : the official journal of the Society for Neuroscience
影响因子：
--
作者：
Dupraz S;Grassi D;Bernis ME;Sosa L;Bisbal M;Gastaldi L;Jausoro I;Cáceres A;Pfenninger KH;Quiroga S
通讯作者：
Quiroga S
影响因子：
19
作者：
Wu H;Rossi G;Brennwald P
通讯作者：
Brennwald P
影响因子：
9.8
作者：
Rosse C;Formstecher E;Boeckeler K;Zhao Y;Kremerskothen J;White MD;Camonis JH;Parker PJ
通讯作者：
Parker PJ
影响因子：
64.5
作者：
Gromley, A;Yeaman, C;Doxsey, SJ
通讯作者：
Doxsey, SJ