期刊
JOURNAL OF MOLECULAR BIOLOGY
卷 424, 期 5, 页码 368-378出版社
ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD
DOI: 10.1016/j.jmb.2012.10.010
关键词
hydrophobicity; membrane insertion; membrane protein; topology
资金
- Swiss National Science Foundation [31003A-125423]
- Swiss National Science Foundation (SNF) [31003A_125423] Funding Source: Swiss National Science Foundation (SNF)
Trans location and insertion of secretory and membrane proteins at the endoplasmic reticulum are mediated by the Sec61 translocon. Evidence from in vivo as well as in vitro experiments indicates that N-terminal signal-anchor sequences initially insert N-first before they invert their orientation to translocate the C-terminus. Inversion is driven by flanking charges according to the positive-inside rule and inhibited by increased signal hydrophobicity. Here, we show that upon extending the N-terminal hydrophilic domain preceding the signal core to more than similar to 20 residues, the insertion behavior changes. Apparent signal inversion and the effect of hydrophobicity are largely lost, suggesting that N-first insertion is limited to N-terminal signal anchors. Extended N-domains sterically hinder N-translocation in a length-dependent manner also for reverse signal anchors with inverted flanking charges. The results indicate a mechanistic difference in the insertion process of N-terminal and internal signal sequences. (C) 2012 Elsevier Ltd. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据