A GTPase cycle in initiation of protein translocation across the endoplasmic reticulum membrane.
A GTPase cycle in initiation of protein translocation across the endoplasmic reticulum membrane.
复制标题
启动蛋白质跨内质网膜易位的 GTP 酶循环。
DOI：
10.1002/9780470514450.ch10
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发表时间：
1993
期刊：
影响因子：
--
通讯作者：
P. Walter
中科院分区：
文献类型：
--
作者：
J. Miller;P. Walter
在高等真核生物中，带有信号序列的蛋白质跨内质网（ER）的膜易位。蛋白质易位的初始事件是信号识别颗粒（SRP）的54 kDa亚基（SRP 54）与信号序列的结合以及核糖体新生链复合物靶向ER。靶向通过SRP与SRP受体的结合介导，SRP受体是一种包含两个不同亚基SR α和SR β的膜蛋白。SRP和SR α/SR β的相互作用导致信号的释放和新生链与膜结合易位装置的接合。SRP 54和SRalpha都含有同源结构域，其包括预测的GTfold。跨膜蛋白SR β也含有一个GTP结构域，但它与SRP 54和SR α的结构域没有密切关系。所有三种蛋白质都特异性结合GTP，并且SR α/SR β复合物刺激GTP与SRP 54的结合和GTP水解。我们提出了一个模型，在启动蛋白质易位的ER中，SR α β催化GTP的结合，水解和释放的SRP 54，调节其从信号序列的解离的循环。
In higher eukaryotes proteins bearing a signal sequence are translocated across the membrane of the endoplasmic reticulum (ER). The initial events of protein translocation are the binding of the signal sequence by the 54 kDa subunit (SRP54) of the signal recognition particle (SRP) and the targeting of the ribosome nascent chain complex to the ER. Targeting is mediated by the binding of SRP to the SRP receptor, a membrane protein comprising two different subunits, SR alpha and SR beta. Interaction of SRP and SR alpha/SR beta causes release of the signal and the engagement of the nascent chain with the membrane-bound translocation apparatus. Both SRP54 and SR alpha contain homologous domains which include a predicted GTPase fold. The transmembrane protein SR beta also contains a GTPase domain, but it is not closely related to those of SRP54 and SR alpha. All three proteins bind GTP specifically, and the SR alpha/SR beta complex stimulates both GTP binding to and GTP hydrolysis by SRP54. We suggest a model for the initiation of protein translocation across the ER in which SR alpha beta catalyses a cycle of GTP binding, hydrolysis and release by SRP54 that regulates its dissociation from the signal sequence.
用 5-三磷酸鸟苷直接光亲和标记微管蛋白。
影响因子：
2.9
作者：
Nath,JP;Eagle,GR;Himes,RH
通讯作者：
Himes,RH
影响因子：
56.9
作者：
JURNAK, F
通讯作者：
JURNAK, F