The Sec61p complex mediates the integration of a membrane protein by allowing lipid partitioning of the transmembrane domain
The Sec61p complex mediates the integration of a membrane protein by allowing lipid partitioning of the transmembrane domain
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DOI：
10.1016/s0092-8674(00)00028-3
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发表时间：
2000-07-21
期刊：
影响因子：
64.5
通讯作者：
Rapoport, TA
中科院分区：
文献类型：
--
作者：
Heinrich, SU;Mothes, W;Rapoport, TA
我们已经研究了膜蛋白的跨膜（TM）结构域是如何协同整合到内质网中的。我们证明，Sec61p通道允许TM域绕过脂质双层的极性头基团所构成的屏障，并与膜的疏水内部接触。Sec61 p与TRAM蛋白一起在膜中通道和脂质的界面处提供位点，TM结构域可以通过该位点在脂质和水相之间动态平衡，这取决于TM结构域的疏水性和将其拴系到核糖体的多肽片段的长度。我们的研究结果提出了一个统一的，脂质分配模型，可以解释疏水拓扑序列的一般行为。
We have investigated how the transmembrane (TM) domain of a membrane protein is cotranslationally integrated into the endoplasmic reticulum. We demonstrate that the Sec61p channel allows the TM domain to bypass the barrier posed by the polar head groups of the lipid bilayer and come into contact with the hydrophobic interior of the membrane. Together with the TRAM protein, Sec61p provides a site in the membrane, at the interface of channel and lipid, through which a TM domain can dynamically equilibrate between the lipid and aqueous phases, depending on the hydrophobicity of the TM domain and the length of the polypeptide segment tethering it to the ribosome. Our results suggest a unifying, lipid-partitioning model which can explain the general behavior of hydrophobic topogenic sequences.