ATP binding regulates oligomerization and endosome association of RME-1 family proteins
ATP binding regulates oligomerization and endosome association of RME-1 family proteins
复制标题
DOI：
10.1074/jbc.m412751200
复制
发表时间：
2005-04-29
影响因子：
4.8
通讯作者：
Greene, LE
中科院分区：
文献类型：
--
作者：
Lee, DW;Zhao, XH;Greene, LE
RME-1/mRme-1/EHD 1蛋白家族的成员最近已显示在膜蛋白从再循环内体到质膜的再循环中起作用。通常发现RME-1家族蛋白与再循环内体以及从这些内体发出的囊泡和小管密切相关，这与这些蛋白直接参与内体转运的提议一致。RME-1家族蛋白含有被认为参与RME-1与其他内吞蛋白连接的C-末端EH（eps 15同源性）结构域、被认为参与同源寡聚化的卷曲螺旋结构域和被认为介导核苷酸结合的N-末端P-环结构域。在本研究中，我们表明，秀丽隐杆线虫和小鼠RME-1蛋白结合和水解ATP。未检测到显著的GTP结合或水解。ATP结合P环的突变或缺失阻止了RME-1寡聚化，同时使RME-1与内体解离。此外，ATP耗竭导致RME-1失去其在细胞内的内体结合，导致胞质定位。总之，这些结果表明ATP结合是mRme-1/EHD 1寡聚化所必需的，而mRme-1/EHD 1寡聚化又是其与内体缔合所必需的。
Members of the RME-1/mRme-1/EHD1 protein family have recently been shown to function in the recycling of membrane proteins from recycling endosomes to the plasma membrane. RME-1 family proteins are normally found in close association with recycling endosomes and the vesicles and tubules emanating from these endosomes, consistent with the proposal that these proteins directly participate in endosomal transport. RME-1 family proteins contain a C-terminal EH (eps15 homology) domain thought to be involved in linking RME-1 to other endocytic proteins, a coiled-coil domain thought to be involved in homo-oligomerization and an N-terminal P-loop domain thought to mediate nucleotide binding. In the present study, we show that both Caenorhabditis elegans and mouse RME-1 proteins bind and hydrolyze ATP. No significant GTP binding or hydrolysis was detected. Mutation or deletion of the ATP-binding P-loop prevented RME-1 oligomerization and at the same time dissociated RME-1 from endosomes. In addition, ATP depletion caused RME-1 to lose its endosome association in the cell, resulting in cytosolic localization. Taken together, these results indicate that ATP binding is required for oligomerization of mRme-1/EHD1, which in turn is required for its association with endosomes.