Sec61alpha and TRAM are sequentially adjacent to a nascent viral membrane protein during its ER integration.
Sec61alpha and TRAM are sequentially adjacent to a nascent viral membrane protein during its ER integration.
复制标题
Sec61alpha 和 TRAM 在新生病毒膜蛋白的 ER 整合过程中依次相邻。
DOI：
10.1016/j.jmb.2006.11.052
复制
发表时间：
2007
影响因子：
5.6
通讯作者：
Mingarro,Ismael
中科院分区：
文献类型：
--
作者：
Saurí,Ana;McCormick,PeterJ;Johnson,ArthurE;Mingarro,Ismael
新生病毒膜蛋白通过转位子共翻译整合到内质网膜中。我们一直在研究的早期阶段的双跨越植物病毒运动蛋白的整合，以深入了解病毒膜蛋白是如何从亲水内部的translocon转移到疏水环境的双层，跨膜（TM）的病毒蛋白片段可以自由扩散。光交联实验表明，这种整合涉及TM片段顺序通过Sec61α和易位链缔合膜蛋白（TRAM）。每个TM段首先与Sec61α相邻，然后与TRAM相邻。TRAM交联在新生链生物发生期间延长很长一段时间。此外，用非病毒TM序列替换第一病毒TM区段仍然产生与TRAM的新生链光加合物。因此，TRAM似乎参与了病毒膜蛋白的整合，并且TRAM的新生链识别似乎不仅仅依赖于TM结构域。
Co-translational integration of a nascent viral membrane protein into the endoplasmic reticulum membrane takes place via the translocon. We have been studying the early stages of the integration of a double-spanning plant viral movement protein to gain insights into how viral membrane proteins are transferred from the hydrophilic interior of the translocon into the hydrophobic environment of the bilayer, where the transmembrane (TM) segments of the viral proteins can diffuse freely. Photocrosslinking experiments reveal that this integration involves the sequential passage of the TM segments past Sec61α and translocating chain-associating membrane protein (TRAM). Each TM segment is first adjacent to Sec61α and subsequently is adjacent to TRAM. TRAM crosslinking extends for a long period during nascent chain biogenesis. In addition, the replacement of the first viral TM segment with a non-viral TM sequence still yields nascent chain photo-adducts with TRAM. TRAM therefore appears to be involved in viral membrane protein integration, and nascent chain recognition by TRAM does not appear to rely solely on the TM domains.