EXTRACELLULAR ASSOCIATION AND CYTOPLASMIC PARTITIONING OF THE IPAB AND IPAC INVASINS OF SHIGELLA-FLEXNERI
EXTRACELLULAR ASSOCIATION AND CYTOPLASMIC PARTITIONING OF THE IPAB AND IPAC INVASINS OF SHIGELLA-FLEXNERI
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DOI：
10.1016/0092-8674(94)90260-7
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发表时间：
1994-11-04
期刊：
影响因子：
64.5
通讯作者：
VASSELON, T
中科院分区：
文献类型：
--
作者：
MENARD, R;SANSONETTI, P;VASSELON, T
志贺氏菌通过侵入结肠上皮细胞引起人类细菌性痢疾。IpaB和IpaC是这些病原体的两种主要入侵物，分泌到细胞外环境中。我们在这里表明，IpaB和IpaC在细胞外介质中形成复合物，并且各自独立地与细菌细胞质中的17 kDa多肽IpgC结合。研究发现，IpgC多肽对于细菌进入上皮细胞、稳定不稳定的IpaB蛋白以及防止IpaC通过与未保护的IpaB结合而发生的蛋白水解降解是必需的。我们认为，不分泌的IpgC作为分子伴侣，可以作为一种受体，防止志贺菌细胞质中IpaB和IpaC的过早寡聚化。
Shigella species cause bacillary dysentery in humans by invading colonic epithelial cells. IpaB and IpaC, two major invasins of these pathogens, are secreted into the extracellular milieu. We show here that IpaB and IpaC form a complex in the extracellular medium and that each binds independently to a 17 kDa polypeptide, IpgC, in the bacterial cytoplasm. The IpgC polypeptide was found to be necessary for bacterial entry into epithelial cells, to stabilize the otherwise unstable IpaB protein, and to prevent the proteolytic degradation of IpaC that occurs through its association with unprotected IpaB. We propose that IpgC, which is not secreted and thus acts as a molecular chaperone, serves as a receptor that prevents premature oligomerization of IpaB and IpaC within the cytoplasm of Shigella cells.