Expression of Vps1 I649K a self-assembly defective yeast dynamin, leads to formation of extended endocytic invaginations.
Expression of Vps1 I649K a self-assembly defective yeast dynamin, leads to formation of extended endocytic invaginations.
复制标题
DOI：
10.4161/cib.4.1.14206
复制
发表时间：
2011-01-01
影响因子：
--
通讯作者：
Ayscough, Kathryn R
中科院分区：
文献类型：
--
作者：
Mishra, Ritu;Smaczynska-de Rooij, Iwona I;Ayscough, Kathryn R
动力蛋白与细胞内吞作用有关已有多年的历史。直到最近，它被认为是酵母动力蛋白相关的蛋白质没有发挥作用的内吞作用和建议的切断功能的动力蛋白归因于另一组蛋白质，两性蛋白。然而，它现在已经表明，酵母动力蛋白样蛋白Vps1显示出一个短暂的爆发定位到网站的内吞作用。Vps1组装在皮质网站的时候，肌动蛋白聚合，提出驱动质膜内陷。与两性蛋白相一致，Vps1被认为在断裂步骤中起作用以释放形成的囊泡。研究表明，阻止Vps1自组装的突变引起内吞作用的缺陷，但不会引起与Vps1相关的其他功能的缺陷。使用电子显微镜，我们现在表明，这种突变I649K，对应于I690K在人类Dyn1，导致形成长的内吞内陷。这些数据表明，Vps1的自我组装的能力，从而刺激其GTdR活性是至关重要的“夹断”阶段的内吞作用，形成一个囊泡。
The dynamin proteins have been associated with the process of endocytosis for many years. Until recently it was considered that yeast dynamin-related proteins did not play a role in endocytosis and the proposed scission function of dynamin was attributed to another group of proteins, the amphiphysins. However, it has now been shown that the yeast dynamin-like protein Vps1 shows a transient burst of localization to sites of endocytosis. Vps1 assembles at cortical sites at the time when actin polymerization is proposed to drive plasma membrane invagination. In concert with the amphiphysins Vps1 is then thought to function in the scission step to release a formed vesicle. It was shown that a mutation preventing self assembly of Vps1 caused a defect in endocytosis but not in other functions with which Vps1 is associated. Using electron microscopy we now show that this mutation I649K, corresponding to I690K in human Dyn1, causes formation of long endocytic invaginations. The data suggest that an ability of Vps1 to self assemble and to thereby stimulate its GTPase activity is critical for the 'pinching-off' stage of endocytosis to form a vesicle.