The psp locus of Yersinia enterocolitica is required for virulence and for growth in vitro when the Ysc type III secretion system is produced
The psp locus of Yersinia enterocolitica is required for virulence and for growth in vitro when the Ysc type III secretion system is produced
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DOI：
10.1046/j.1365-2958.2001.02235.x
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发表时间：
2001-01-01
影响因子：
3.6
通讯作者：
Miller, VL
中科院分区：
文献类型：
--
作者：
Darwin, AJ;Miller, VL
大肠杆菌的噬菌体休克蛋白基因座（pspFpspABCDE）自被发现以来一直是一个谜。 psp 基因座的生理功能，包括预测的效应蛋白 PspA 的生理功能，尚不清楚。在之前的基因筛选中，我们确定小肠结肠炎耶尔森氏菌 pspC 突变体的毒力严重减弱。在本研究中，进一步鉴定了小肠结肠炎耶尔森氏菌的 psp 基因座。当 Ysc III 型分泌系统在实验室表达时，发现小肠结肠炎耶尔森氏菌的 pspC 基因对于正常生长很重要。这种生长缺陷具体是由促胰液素蛋白 YscC 的产生引起的。当III型分泌系统发挥功能或仅表达yscC基因时，诱导psp基因的表达。 psp 基因表达的诱导需要有功能的 pspC 基因。最重要的是，有证据表明至少一种不属于 psp 基因座的基因的表达受到 Psp 蛋白的调节。当 III 型分泌系统表达时，这种未鉴定的基因（或多个基因）可能对生长也很重要。这些结论得到了各种 psp 突变对毒力的影响的支持。这是 Psp 蛋白可能参与 psp 基因座本身之外的基因调节的第一个迹象。
The phage shock protein locus (pspFpspABCDE) of Escherichia coli has proved to be something of an enigma since its discovery. The physiological functions of the psp locus, including those of the predicted effector protein PspA, are unknown. In a previous genetic screen, we determined that a Yersinia enterocolitica pspC mutant was severely attenuated for virulence. In this study, the psp locus of Y. enterocolitica was characterized further. The pspC gene of Y. enterocolitica was found to be important for normal growth when the Ysc type III secretion system was expressed in the laboratory. This growth defect was specifically caused by production of the secretin protein, YscC. Expression of the psp genes was induced when the type III secretion system was functional or when only the yscC gene was expressed. This induction of psp gene expression required a functional pspC gene. Most significantly, evidence suggests that the expression of at least one gene that is not part of the psp locus is regulated by Psp proteins. This unidentified gene (or genes) may also be important for growth when the type III secretion system is expressed. These conclusions are supported by the effects of various psp mutations on virulence. This is the first indication that Psp proteins might be involved in the regulation of genes besides the psp locus itself.