The extracytoplasmic adaptor protein CpxP is degraded with substrate by DegP
The extracytoplasmic adaptor protein CpxP is degraded with substrate by DegP
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DOI：
10.1073/pnas.0508936102
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发表时间：
2005-12-06
影响因子：
11.1
通讯作者：
Silhavy, TJ
中科院分区：
文献类型：
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作者：
Isaac, DD;Pinkner, JS;Silhavy, TJ
在大肠杆菌中，CpxR/A双组分系统感知各种类型的胞外压力，并通过激活编码周质蛋白折叠和运输因子的基因的表达来做出反应，以清除这些压力，以确保有机体的生存。CpxP基因编码一种小的、能抵抗压力的周质蛋白，是cpx调节子中诱导作用最强的成员。我们证明了CPX应激反应抑制了来自致尿路病原性大肠杆菌P菌毛的两个错误折叠蛋白的毒性，并且cpxP或周质蛋白酶DegP基因的突变通过阻止这些蛋白的降解来防止抑制。值得注意的是，周质错误折叠蛋白底物的存在显著增强了DegP对CpxP的蛋白质分解。我们的数据表明，CpxP作为一种周质适配蛋白发挥作用，这是DegP蛋白酶有效地分解一组错误折叠的底物所必需的。
In Escherichia coli, the CpxR/A two-component system senses various types of extracytoplasmic stresses and responds by activating the expression of genes encoding periplasmic protein folding and trafficking factors that clear such stresses to ensure the organism's survival. The cpxP gene encodes a small, stress-combative periplasmic protein and is the most strongly induced member of the Cpx regulon. We demonstrate that the Cpx stress response suppresses the toxicity associated with two misfolded proteins derived from the P pilus of uropathogenic E. coli and that mutations in either cpxP or the gene for the periplasmic protease DegP prevent suppression by preventing the degradation of these proteins. Strikingly, the presence of a periplasmic misfolded protein substrate significantly enhances the proteolysis of CpxP by DegP. Our data suggest that CpxP functions as a periplasmic adaptor protein that is required for the effective proteolysis of a subset of misfolded substrates by the DegP protease.