Suppression by enhanced RpoE activity of the temperature-sensitive phenotype of a degP ssrA double mutant in Escherichia coli.
Suppression by enhanced RpoE activity of the temperature-sensitive phenotype of a degP ssrA double mutant in Escherichia coli.
复制标题
通过增强 RpoE 活性来抑制大肠杆菌中 degP ssrA 双突变体的温度敏感表型。
作者：
K. Ono;K. Kutsukake;T. Abo
SsrA是在反式翻译中起关键作用的小RNA，其导致拯救mRNA上或末端的停滞核糖体并将降解标签添加到生长的多肽中。SsrA的缺失已经显示出增强E.大肠杆菌菌株degP基因缺陷，该基因编码一种周质蛋白酶。这种严重的TS表型仅部分缓解的SsrADD变体，这可以导致核糖体救援，但增加了蛋白酶抗性标签，而不是降解标签，这表明截短的mRNA编程的多肽的积累是负责生长缺陷的ssrA degP突变体。S210A突变型DegP蛋白的表达，缺乏蛋白酶活性，但保留了伴侣活性，可以缓解双突变体的ts表型，这表明在高温下ssrA缺陷细胞的生长需要DegP的伴侣活性，而不是蛋白酶活性。rpoE基因的过表达，它编码sigmaE负责参与细胞外应激反应的因子的表达，也抑制了ssrA degP突变体的TS表型。这表明在SsrA缺失的情况下，应激反应途径可能参与degP突变体ts表型的增强。
SsrA is a small RNA playing a crucial role in trans-translation, which leads to rescue of stalled ribosomes on or at the end of mRNA and addition of the degradation tag to a growing polypeptide. The lack of SsrA has been shown to enhance the temperature-sensitive (ts) phenotype of an E. coli strain defective in the degP gene, which encodes one of the periplasmic proteases. This severe ts phenotype was relieved only partially by an SsrADD variant, which can lead to ribosome rescue but adds a protease-resistant tag instead of the degradation tag, suggesting that accumulation of polypeptides programmed by truncated mRNAs is responsible for growth defect of the ssrA degP mutant. Expression of an S210A-mutant DegP protein, which lacks the protease activity but retains the chaperone activity, could relieve the ts phenotype of the double mutant, suggesting that the chaperone activity but not the protease activity of DegP is required for growth of the ssrA-deficient cells at high temperature. Overexpression of the rpoE gene, which encodes sigmaE responsible for the expression of factors involved in extracellular stress response, also suppressed the ts phenotype of the ssrA degP mutant. This suggests that the stress-responsing pathway(s) may be involved in the enhancement of ts phenotype of degP mutant in the absence of SsrA.
影响因子：
10.5
作者：
ERICKSON, JW;GROSS, CA
通讯作者：
GROSS, CA
影响因子：
10.5
作者：
DANESE, PN;SNYDER, WB;SILHAVY, TJ
通讯作者：
SILHAVY, TJ