Dynamin at actin tails
Dynamin at actin tails
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DOI：
10.1073/pnas.012607799
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发表时间：
2002-01-08
影响因子：
11.1
通讯作者：
De Camilli, P
中科院分区：
文献类型：
--
作者：
Lee, E;De Camilli, P
动力蛋白是果蝇shibire基因的产物，是内吞作用所必需的一种GT3。一些研究表明发动蛋白和肌动蛋白细胞骨架之间存在功能性联系。这种联系是特别感兴趣的，因为有证据表明，肌动蛋白动力学的内吞作用。在这里，我们表明，内源性发动蛋白2，以及绿色荧光蛋白融合蛋白的发动蛋白1和2，存在于肌动蛋白彗星产生的李斯特菌或I型PIP激酶（PIPK）过表达。在PIPK诱导的尾部，发动蛋白进一步富集在尾部和移动的细胞器之间的界面。发动蛋白突变体在GT3结构域中含有突变，抑制了PIPK诱导的肌动蛋白尾部成核，并适度降低了它们的速度。虽然发动蛋白的本地化的尾巴需要其富含脯氨酸的结构域，表达的发动蛋白突变体缺乏这一领域也减少了尾巴的形成。此外，该突变体破坏了先前显示包括发动蛋白的膜相关肌动蛋白支架（podosome玫瑰花结）。这些发现表明，发动蛋白是蛋白质网络的一部分，控制肌动蛋白从膜成核。在内吞部位，发动蛋白可能将分裂反应与肌动蛋白池的聚合偶联，肌动蛋白池在内吞囊泡与质膜的分离中起作用。
Dynamin, the product of the shibire gene of Drosophila, is a GTPase critically required for endocytosis. Some studies have suggested a functional link between dynamin and the actin cytoskeleton. This link is of special interest, because there is evidence implicating actin dynamics in endocytosis. Here we show that endogenous dynamin 2, as well as green fluorescence protein fusion proteins of both dynamin 1 and 2, is present in actin comets generated by Listeria or by type I PIP kinase (PIPK) overexpression. In PIPK-induced tails, dynamin is further enriched at the interface between the tails and the moving organelles. Dynamin mutants harboring mutations in the GTPase domain inhibited nucleation of actin tails induced by PIPK and moderately reduced their speed. Although dynamin localization to the tails required its proline-rich domain, expression of a dynamin mutant lacking this domain also diminished tail formation. in addition, this mutant disrupted a membrane-associated actin scaffold (podosome rosette) previously shown to include dynamin. These findings suggest that dynamin is part of a protein network that controls nucleation of actin from membranes. At endocytic sites, dynamin may couple the fission reaction to the polymerization of an actin pool that functions in the separation of the endocytic vesicles from the plasma membrane.