Degradation versus aggregation of misfolded maltose-binding protein in the periplasm of Escherichia coli
Degradation versus aggregation of misfolded maltose-binding protein in the periplasm of Escherichia coli
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DOI：
10.1074/jbc.273.15.8897
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发表时间：
1998-04-10
影响因子：
4.8
通讯作者：
Laurent, M
中科院分区：
文献类型：
--
作者：
Betton, JM;Sassoon, N;Laurent, M
通过操纵影响宿主细胞中蛋白质折叠途径的两种细胞活性来确定错误折叠的MalE31（麦芽糖结合蛋白的缺陷折叠突变体）的周质命运：（i）malEp启动子活性，其由转录激活因子MalT控制，和（ii）DegP和蛋白酶III周质蛋白水解活性。在低水平的表达，降解的错误折叠的MalE31在缺乏DegP或蛋白酶III的细胞部分受损。在高水平表达时，错误折叠的MalE31迅速形成周质包涵体，从而逃避降解，然而，操纵的宿主细胞活性并没有增强周质可溶性MalE31的产生。折叠，聚集和降解之间的动力学竞争提出了作为一个通用模型的周质蛋白质的生物合成。
The periplasmic fates of misfolded MalE31, a defective folding mutant of the maltose-binding protein, were determined by manipulating two cellular activities affecting the protein folding pathway in host cells: (i) the malEp promoter activity, which is controlled by the transcriptional activator MalT, and (ii) the DegP and Protease III periplasmic proteolytic activity. At a low level of expression, the degradation of misfolded MalE31 was partially impaired in cells lacking DegP or Protease III. At a high level of expression, misfolded MalE31 rapidly formed periplasmic inclusion bodies and thus escaped degradation, However, the manipulated host cell activities did not enhance the production of periplasmic, soluble MalE31. A kinetic competition between folding, aggregation, and degradation is proposed as a general model for the biogenesis of periplasmic proteins.