Secretion monitor, SecM, undergoes self-translation arrest in the cytosol
Secretion monitor, SecM, undergoes self-translation arrest in the cytosol
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DOI：
10.1016/s1097-2765(01)00166-6
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发表时间：
2001-01-01
期刊：
影响因子：
16
通讯作者：
Ito, K
中科院分区：
文献类型：
--
作者：
Nakatogawa, H;Ito, K
大肠杆菌secM基因（分泌监测基因，以前称为基因X）位于secA上游，其产物参与对SecA翻译的分泌响应调控。在野生型细胞中，SecM会被周质尾特异性蛋白酶迅速降解。它在靠近C末端的位置还会经历短暂的翻译暂停。当SecM的易位受损时，延伸停滞会显著延长。这种停滞不需要信号识别颗粒（SRP）。相反，新生的SecM产物自身可能参与其中，因为当它掺入脯氨酸类似物氮杂环丁烷时，停滞会减弱。我们提出，细胞质定位的新生SecM会发生自我翻译停滞，从而通过改变secM - secA信使RNA的二级结构来增强secA的翻译。
The product of the Escherichia coli secM gene (secretion monitor, formerly gene X), upstream of secA, is involved in secretion-responsive control of SecA translation. In wild-type cells, SecM is rapidly degraded by the periplasmic tail-specific protease. It is also subject to a transient translation pause at a position close to the C terminus. The elongation arrest was strikingly prolonged when translocation of SecM was impaired. SRP was not required for this arrest. Instead, the nascent SecM product itself may participate, as the arrest was diminished when it incorporated a proline analog, azetidine. We propose that cytosolically localized nascent SecM undergoes self-translation arrest, thereby enhancing translation of secA through an altered secondary structure of the secM-secA messenger RNA.