Synthesis and localization of the Salmonella SPI-1 type III secretion needle complex proteins PrgI and PrgJ
Synthesis and localization of the Salmonella SPI-1 type III secretion needle complex proteins PrgI and PrgJ
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DOI：
10.1128/jb.185.11.3480-3483.2003
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发表时间：
2003-06-01
影响因子：
3.2
通讯作者：
Galán, JE
中科院分区：
文献类型：
--
作者：
Sukhan, A;Kubori, T;Galán, JE
III型分泌系统（TTSS）的一个重要组成部分是一个超分子结构，称为针复合物。在肠道沙门氏菌中，至少有四种蛋白质组成这种结构：InvG，PrgH，PrgK和PrgI。另一种蛋白质PrgJ被认为在这种结构的组装中发挥作用，但其功能知之甚少。我们分析了PrgJ和针蛋白PrgI在不同S.肠血清型鼠伤寒突变株。我们发现，PrgI和PrgJ的水平显着降低在TTSS缺陷型invA突变株和水平的降低是由于蛋白质的不稳定性。此外，我们发现PrgJ虽然与野生型S.肠血清型鼠伤寒沙门氏菌，不存在于从invJ突变株获得的针复合物中，其表现出非常长的针亚结构。我们认为，PrgJ参与封盖针复杂的针子结构。
An essential component of type III secretion systems (TTSS) is a supramolecular structure termed the needle complex. In Salmonella enterica, at least four proteins make up this structure: InvG, PrgH, PrgK, and PrgI. Another protein, PrgJ, is thought to play a role in the assembly of this structure, but its function is poorly understood. We have analyzed the expression and localization of PrgJ and the needle protein PrgI in different S. enterica serovar Typhimurium mutant strains. We found that the levels of PrgI and PrgJ were significantly reduced in a TTSS-deficient invA mutant strain and that the decreased levels were due to protein instability. In addition, we found that PrgJ, although associated with the needle complex in wild-type S. enterica serovar Typhimurium, was absent from needle complexes obtained from an invJ mutant strain, which exhibits very long needle substructures. We suggest that PrgJ is involved in capping the needle substructure of the needle complex.