AN INTERNAL SIGNAL SEQUENCE - THE ASIALOGLYCOPROTEIN RECEPTOR MEMBRANE ANCHOR
AN INTERNAL SIGNAL SEQUENCE - THE ASIALOGLYCOPROTEIN RECEPTOR MEMBRANE ANCHOR
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DOI：
10.1016/0092-8674(86)90496-4
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发表时间：
1986-01-01
期刊：
影响因子：
64.5
通讯作者：
LODISH, HF
中科院分区：
文献类型：
--
作者：
SPIESS, M;LODISH, HF
人去唾液酸糖蛋白受体H1由20个疏水氨基酸组成，固定在细胞膜上；亲水性氨基末端面向细胞质，而羧基末端是外质。我们在这里表明，去唾液酸糖蛋白受体的糖基化和插入内质网膜是共翻译的和SRP依赖的，并且不发生蛋白水解性切割。膜锚定结构域对于膜插入是必需的，因为缺失该片段的受体既不插入也不糖基化。该片段也足以用于膜插入，因为它将启动大鼠α-微管蛋白的羧基末端结构域跨膜的移位。我们认为，膜插入的螺旋发夹机制既适用于切割的氨基末端，也适用于未切割的内部信号序列。
The human asialoglycoprotein receptor H1 is anchored in the membrane by a single stretch of 20 hydrophobic amino acids; the hydrophilic amino terminus faces the cytoplasm, and the carboxyl terminus is exoplasmic. We show here that glycosylation and insertion of the asialoglycoprotein receptor into the endoplasmic reticulum membrane is cotranslational and SRP-dependent and occurs without proteolytic cleavage. The membrane-anchor domain is necessary for membrane insertion, since a receptor with the segment deleted is neither inserted nor glycosylated. The segment is also sufficient for membrane insertion, since it will initiate translocation of a carboxy-terminal domain of rat .alpha.-tubulin across the membrane. We propose that a helical hairpin mechanism of membrane insertion is used both by cleaved amino-terminal and uncleaved internal signal sequences.