Sönnichsen B, Lowe M, Levine T, Jämsä E, Dirac-Svejstrup B, Warren G
Cell Biology Laboratory, Imperial Cancer Research Fund, London WC2A, 3PX, United Kingdom.
J Cell Biol. 1998 Mar 9;140(5):1013-21. doi: 10.1083/jcb.140.5.1013.
We have previously shown that p115, a vesicle docking protein, binds to two proteins (p130 and p400) in detergent extracts of Golgi membranes. p130 was identified as GM130, a Golgi matrix protein, and was shown to act as a membrane receptor for p115. p400 has now been identified as giantin, a Golgi membrane protein with most of its mass projecting into the cytoplasm. Giantin is found on COPI vesicles and pretreatment with antibodies inhibits both the binding of p115 and the docking of these vesicles with Golgi membranes. In contrast, GM130 is depleted from COPI vesicles and inhibition of the GM130 on Golgi membranes, using either antibodies or an NH2-terminal GM130 peptide, inhibits p115 binding and vesicle docking. Together these results suggest that COPI vesicles are docked by giantin on the COPI vesicles and GM130 on Golgi membranes with p115 providing a bridge.
我们之前已经表明，囊泡对接蛋白p115在高尔基体膜的去污剂提取物中与两种蛋白（p130和p400）结合。p130被鉴定为GM130，一种高尔基体基质蛋白，并被证明可作为p115的膜受体。p400现已被鉴定为巨蛋白，一种高尔基体膜蛋白，其大部分质量伸向细胞质。巨蛋白存在于COPI囊泡上，用抗体预处理可抑制p115的结合以及这些囊泡与高尔基体膜的对接。相比之下，GM130从COPI囊泡中耗尽，使用抗体或NH2端GM130肽抑制高尔基体膜上的GM130会抑制p115结合和囊泡对接。这些结果共同表明，COPI囊泡通过巨蛋白停靠在COPI囊泡上，通过高尔基体膜上的GM130停靠，而p115起到桥梁作用。
