Tail-anchored and signal-anchored proteins utilize overlapping pathways during membrane insertion
Tail-anchored and signal-anchored proteins utilize overlapping pathways during membrane insertion
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DOI：
10.1074/jbc.m209968200
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发表时间：
2003-02-21
影响因子：
4.8
通讯作者：
High, S
中科院分区：
文献类型：
--
作者：
Abell, BM;Jung, M;High, S
尾锚蛋白是一类独特的膜蛋白，其特点是具有c端膜插入序列和翻译后整合能力。虽然现在很清楚尾巴锚定蛋白是插入到内质网的膜上的。（ER），它们整合的分子基础尚不清楚。我们使用交联方法来鉴定可能参与尾锚定蛋白膜插入的内质网成分。我们发现一些新合成的尾部锚定蛋白与细胞成分的一个定义子集短暂相关。其中，我们鉴定了几种内质网蛋白，包括Sec61易位、Sec62p、Sec63p的亚基，以及信号肽酶复合物的25 kda亚基。当我们分析一个类似的信号锚定蛋白的共翻译膜插入时，我们发现新生多肽与一组类似的内质网成分相关。我们得出的结论是，尾锚定和信号锚定膜蛋白在内质网的整合途径表现出相当程度的重叠，我们认为这反映了共同和翻译后膜插入之间的相似性。
Tail-anchored proteins are a distinct class of membrane proteins that are characterized by a C-terminal membrane insertion sequence and a capacity for post-translational integration. Although it is now clear that tail-anchored proteins are inserted into the membrane at the endoplasmic reticulum. (ER), the molecular basis for their integration is poorly understood. We have used a cross-linking approach to identify ER components that may be involved in the membrane insertion of tail-anchored proteins. We find that several newly synthesized tail-anchored proteins are transiently associated with a defined subset of cellular components. Among these, we identify several ER proteins, including subunits of the Sec61 translocon, Sec62p, Sec63p, and the 25-kDa subunit of the signal peptidase complex. When we analyze the cotranslational membrane insertion of a comparable signal-anchored protein we find the nascent polypeptide associated with a similar set of ER components. We conclude that the pathways for the integration of tail-anchored and signal-anchored membrane proteins at the ER exhibit a substantial degree of overlap, and we propose that this reflects similarities between co- and post-translational membrane insertion.