Evidence for physical and functional interactions among two Saccharomyces cerevisiae SH3 domain proteins, an adenylyl cyclase-associated protein and the actin cytoskeleton
Evidence for physical and functional interactions among two Saccharomyces cerevisiae SH3 domain proteins, an adenylyl cyclase-associated protein and the actin cytoskeleton
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DOI：
10.1091/mbc.8.2.367
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发表时间：
1997-02-01
影响因子：
3.3
通讯作者：
Drubin, DG
中科院分区：
文献类型：
--
作者：
Lila, T;Drubin, DG
在许多生物体中，与皮层肌动蛋白细胞骨架相关的许多蛋白质含有SH3结构域，这表明这些结构域可能为肌动蛋白细胞骨架中的结构蛋白和调节蛋白之间的功能相互作用提供物理基础。我们目前的证据表明，SH3域介导至少两个独立的功能的酿酒酵母肌动蛋白结合蛋白ABP1P在体内。Abp1p包含一个单一的SH3结构域，最近已被证明在体外结合腺苷酸环化酶相关蛋白Srv2p。在ABP1或SRV2携带突变的菌株Srv2p亚细胞定位的免疫荧光分析表明，ABP1p SH3结构域介导Srv2p与皮质肌动蛋白细胞骨架的正常关联。我们还表明，一个网站在Abp1p本身是由肌动蛋白相关蛋白Rvs167p的SH3结构域特异性结合。遗传分析提供的证据表明，Abp1p和Rvs167p具有密切相关的功能。Abp1无效突变，如rvs167突变，在某些次优生长条件下导致孢子形成缺陷和活力降低。此外，ABP1和RVS167的突变与编码其他细胞骨架成分的基因突变结合时，产生类似的遗传“合成致死”相互作用谱。然而，特异性破坏SH 3结构域介导的Abp 1p和Srv 2p之间相互作用的突变并未显示出abp 1和rvs 167突变的共同表型。我们的结论是，Abp1p SH3域介导的协会Srv2p与皮质肌动蛋白细胞骨架，和Abp1p执行一个独特的功能，可能涉及Rvs167p SH3域的结合。总之，这里介绍的工作说明了SH3域如何整合多种肌动蛋白细胞骨架蛋白的活动，以应对不同的环境条件。
n a variety of organisms, a number of proteins associated with the cortical actin cytoskeleton contain SH3 domains, suggesting that these domains may provide the physical basis for functional interactions among structural and regulatory proteins in the actin cytoskeleton. We present evidence that SH3 domains mediate at least two independent functions of the Saccharomyces cerevisiae actin-binding protein Abp1p in vivo. Abp1p contains a single SH3 domain that has recently been shown to bind in vitro to the adenylyl cyclase-associated protein Srv2p. Immunofluorescence analysis of Srv2p subcellular localization in strains carrying mutations in either ABP1 or SRV2 reveals that the Abp1p SH3 domain mediates the normal association of Srv2p with the cortical actin cytoskeleton. We also show that a site in Abp1p itself is specifically bound by the SH3 domain of the actin-associated protein Rvs167p. Genetic analysis provides evidence that Abp1p and Rvs167p have functions that are closely interrelated. Abp1 null mutations, like rvs167 mutations, result in defects in sporulation and reduced viability under certain suboptimal growth conditions. In addition, mutations in ABP1 and RVS167 yield similar profiles of genetic ''synthetic lethal'' interactions when combined with mutations in genes encoding other cytoskeletal components. Mutations which specifically disrupt the SH3 domain-mediated interaction between Abp1p and Srv2p, however, show none of the shared phenotypes of abp1 and rvs167 mutations. We conclude that the Abp1p SH3 domain mediates the association of Srv2p with the cortical actin cytoskeleton, and that Abp1p performs a distinct function that is likely to involve binding by the Rvs167p SH3 domain. Overall, work presented here illustrates how SH3 domains can integrate the activities of multiple actin cytoskeleton proteins in response to varying environmental conditions.