Srv2/CAP is required for polarized actin cable assembly and patch internalization during clathrin-mediated endocytosis
Srv2/CAP is required for polarized actin cable assembly and patch internalization during clathrin-mediated endocytosis
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DOI：
10.1242/jcs.176651
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发表时间：
2016-01-15
影响因子：
4
通讯作者：
Toshima, Jiro
中科院分区：
文献类型：
--
作者：
Toshima, Junko Y.;Horikomi, Chika;Toshima, Jiro
肌动蛋白丝的动态组装和分解对于胞吞过程中囊泡的形成和运输至关重要。在酵母中，两种类型的肌动蛋白结构，即皮质斑块和细胞质电缆，在内吞作用中发挥直接作用，但它们的相互作用如何调节仍不清楚。在这里，我们发现 Srv2/CAP 是一种进化上保守的肌动蛋白调节因子，它是有效内吞作用所必需的，因为它在帮助初始囊泡内陷的肌动蛋白斑块和这些肌动蛋白电缆所沿的肌动蛋白电缆的形成中发挥作用。 SRV2 基因的删除导致异常断裂的肌动蛋白电缆的出现，这些肌动蛋白电缆经常移动经过肌动蛋白斑块，即内吞作用的位点。我们发现 Srv2p 的 C 端 CARP 结构域对于肌动蛋白片和电缆的正确组装至关重要；我们还证明，Srv2 的 N 端螺旋折叠结构域是其定位到肌动蛋白斑块所必需的，特别是通过与丝切蛋白相互作用定位到 ADP-肌动蛋白丰富区域。这些结果证明了 Srv2p 在网格蛋白介导的内吞作用期间调节肌动蛋白细胞骨架的体内作用。
The dynamic assembly and disassembly of actin filaments is essential for the formation and transport of vesicles during endocytosis. In yeast, two types of actin structures, namely cortical patches and cytoplasmic cables, play a direct role in endocytosis, but how their interaction is regulated remains unclear. Here, we show that Srv2/CAP, an evolutionarily conserved actin regulator, is required for efficient endocytosis owing to its role in the formation of the actin patches that aid initial vesicle invagination and of the actin cables that these move along. Deletion of the SRV2 gene resulted in the appearance of aberrant fragmented actin cables that frequently moved past actin patches, the sites of endocytosis. We find that the C-terminal CARP domain of Srv2p is vitally important for the proper assembly of actin patches and cables; we also demonstrate that the N-terminal helical folded domain of Srv2 is required for its localization to actin patches, specifically to the ADP-actin rich region through an interaction with cofilin. These results demonstrate the in vivo roles of Srv2p in the regulation of the actin cytoskeleton during clathrin-mediated endocytosis.