An interaction between Sla1p and Sla2p plays a role in regulating actin dynamics and endocytosis in budding yeast
An interaction between Sla1p and Sla2p plays a role in regulating actin dynamics and endocytosis in budding yeast
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DOI：
10.1242/jcs.00454
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发表时间：
2003-06-15
影响因子：
4
通讯作者：
Ayscough, KR
中科院分区：
文献类型：
--
作者：
Gourlay, CW;Dewar, H;Ayscough, KR
动态肌动蛋白细胞骨架对于促进内吞作用的重要性在芽殖酵母中已被认识多年，并且在哺乳动物细胞中越来越被认识。然而，肌动蛋白募集的机制及其在内吞作用中的作用尚不清楚。在这里，我们展示了两种酵母蛋白在这个过程中的重要性。我们证明，Sla 1 p和Sla 2 p在体外和体内相互作用，这种相互作用是由Sla 2 p的中央结构域介导的，其中包括其卷曲螺旋区域，并由Sla 1 p的残基118和361之间的结构域。过度表达。的相互作用片段的Sla 1 p导致减少液相内吞作用，有趣的是，在随后的运输到液泡的缺陷。我们表明，Sla 2 p是所需的极化本地化的Sla 1 p在细胞中，但不是其皮质本地化或其重叠本地化与肌动蛋白。Deltasla 1 Deltasla 2双突变体的产生表明，Sla 2 p很可能在内吞作用中作用于Sla 1 p的上游，而对latrunculin-A的敏感性表明该蛋白质对肌动蛋白动力学具有相反的影响。我们建议，Sla 2 p招募Sla 1 p的内吞网站。然后，Sla 1 p及其相关蛋白Pan 1 p通过与Arp 2/3和Arp 2/3激活蛋白Abp 1 p和Lasl 7/Bee 1 p的相互作用来调节肌动蛋白组装。
The importance of a dynamic actin cytoskeleton for facilitating endocytosis has been recognised for many years in budding yeast and is increasingly recognised in mammalian cells. However, the mechanism for actin recruitment and the role it plays in endocytosis is unclear. Here we show the importance of two yeast proteins in this process. We demonstrate that Sla1p and Sla2p interact in vitro and in vivo and that this interaction is mediated by the central domain of Sla2p, which includes its coiled-coil region, and by a domain of Sla1p between residues 118 and 361. Overexpression. of the interacting fragment of Sla1p causes reduced fluid-phase endocytosis and, interestingly, defects in subsequent trafficking to vacuoles. We show that Sla2p is required for the polarised localisation of Sla1p in cells but not for its cortical localisation or for its overlapping localisation with actin. Generation of an Deltasla1Deltasla2 double mutant demonstrates that Sla2p is likely to act upstream of Sla1p in endocytosis, whereas sensitivity to latrunculin-A suggests that the proteins have opposite effects on actin dynamics. We propose that Sla2p recruits Sla1p to endocytic sites. Sla1p and its associated protein Pan1p then regulate actin assembly through interactions with Arp2/3 and Arp2/3-activating proteins Abp1p and Lasl7/Bee1p.