Novel proteins linking the actin cytoskeleton to the endocytic machinery in Saccharomyces cerevisiae
Novel proteins linking the actin cytoskeleton to the endocytic machinery in Saccharomyces cerevisiae
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DOI：
10.1091/mbc.e02-05-0262
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发表时间：
2002-10-01
影响因子：
3.3
通讯作者：
Ayscough, KR
中科院分区：
文献类型：
--
作者：
Dewar, H;Warren, DT;Ayscough, KR
在酵母中已经清楚地证明了将内吞过程与调节肌动蛋白动力学的因子偶联的重要性，并且已经鉴定和表征了参与这些机制的许多蛋白质。在这里，我们证明了两个额外的皮质成分，Ysc 84 p和Lsb 5 p，这两个共同的肌动蛋白细胞骨架的组织和流体相内吞作用是必不可少的重要性。Ysc 84 p和Lsb 5 p都是通过具有接头蛋白Sla 1 p的不同结构域的双杂交筛选来鉴定的。Ysc 84 p与皮质肌动蛋白共定位，并且其皮质定位需要完整的肌动蛋白细胞骨架的存在。Yc 1034 w/Lsb 5 p定位于细胞皮层，但不与肌动蛋白共定位。Lsb 5蛋白含有推定的VHS和GAT结构域以及NPF基序，它们都是参与膜运输的蛋白质的特征结构域。单独缺失任一基因不会赋予细胞任何显著的表型。然而，这两个基因的缺失在高温下是致命的。此外，在所有温度下，这种双突变体具有去极化肌动蛋白和几乎检测不到的液相内吞作用。我们的数据表明，Ysc 84 p和Lsb 5 p是参与重叠途径耦合内吞作用与肌动蛋白细胞骨架在酵母中的复合物的重要组成部分。
The importance of coupling the process of endocytosis to factors regulating actin dynamics has been clearly demonstrated in yeast, and many proteins involved in these mechanisms have been identified and characterized. Here we demonstrate the importance of two additional cortical components, Ysc84p and Lsb5p, which together are essential for the organization of the actin cytoskeleton and for fluid phase endocytosis. Both Ysc84p and Lsb5p were identified through two-hybrid screens with different domains of the adaptor protein Sla1p. Ysc84p colocalizes with cortical actin and requires the presence of an intact actin cytoskeleton for its cortical localization. Yc1034w/Lsb5p localizes to the cell cortex but does not colocalize with actin. The Lsb5 protein contains putative VHS and GAT domains as well as an NPF motif, which are all domains characteristic of proteins involved in membrane trafficking. Deletion of either gene alone does not confer any dramatic phenotype on cells. However, deletion of both genes is lethal at elevated temperatures. Furthermore, at all temperatures this double mutant has depolarized actin and an almost undetectable level of fluid phase endocytosis. Our data demonstrate that Ysc84p and Lsb5p are important components of complexes involved in overlapping pathways coupling endocytosis with the actin cytoskeleton in yeast.