Differential requirements for clathrin in receptor-mediated endocytosis and maintenance of synaptic vesicle pools
Differential requirements for clathrin in receptor-mediated endocytosis and maintenance of synaptic vesicle pools
复制标题
DOI：
10.1073/pnas.0809541106
复制
发表时间：
2009-01
期刊：
影响因子：
--
通讯作者：
Ken Sato;G. Ernstrom;Shigeki Watanabe;R. Weimer;Chih-Hsiung Chen;Miyuki Sato;Ayesha Siddiqui;E. Jorgensen;B. Grant
中科院分区：
文献类型：
--
作者：
Ken Sato;G. Ernstrom;Shigeki Watanabe;R. Weimer;Chih-Hsiung Chen;Miyuki Sato;Ayesha Siddiqui;E. Jorgensen;B. Grant
网格蛋白是一种外壳蛋白，参与细胞内几个膜结合区室的囊泡出芽。在这里，我们对多细胞动物中网格蛋白重链 (CHC) 的温度敏感 (ts) 突变体进行了分析。正如预期的那样，秀丽隐杆线虫 chc-1(b1025ts) 突变动物在受体介导的内吞作用方面存在缺陷，并且在转移到限制温度后很快就停止发育。这些突变体的稳态网格蛋白水平在所有温度下均降低了 95% 以上。中心相互作用和膜关联在限制温度下消失。由于神经系统缺陷，chc-1(b1025ts) 动物在暴露于限制温度的几分钟内就会瘫痪。令人惊讶的是，chc-1(b1025ts) 动物的突触小泡数量并未减少。与正常的囊泡数量一致，突触后微型电流以正常频率发生。综上所述，这些结果表明，非神经元细胞中受体介导的内吞作用需要高水平的 CHC 活性，但对于突触小泡池的维持来说，CHC 活性在很大程度上是可有可无的。
Clathrin is a coat protein involved in vesicle budding from several membrane-bound compartments within the cell. Here we present an analysis of a temperature-sensitive (ts) mutant of clathrin heavy chain (CHC) in a multicellular animal. As expected Caenorhabditis elegans chc-1(b1025ts) mutant animals are defective in receptor-mediated endocytosis and arrest development soon after being shifted to the restrictive temperature. Steady-state clathrin levels in these mutants are reduced by more than 95% at all temperatures. Hub interactions and membrane associations are lost at the restrictive temperature. chc-1(b1025ts) animals become paralyzed within minutes of exposure to the restrictive temperature because of a defect in the nervous system. Surprisingly synaptic vesicle number is not reduced in chc-1(b1025ts) animals. Consistent with the normal number of vesicles, postsynaptic miniature currents occur at normal frequencies. Taken together, these results indicate that a high level of CHC activity is required for receptor-mediated endocytosis in nonneuronal cells but is largely dispensable for maintenance of synaptic vesicle pools.