GRB2 links signaling to actin assembly by enhancing interaction of neural Wiskott-Aldrich syndrome protein (N-WASp) with actin-related protein (ARP2/3) complex
GRB2 links signaling to actin assembly by enhancing interaction of neural Wiskott-Aldrich syndrome protein (N-WASp) with actin-related protein (ARP2/3) complex
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DOI：
10.1074/jbc.m000687200
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发表时间：
2000-07-21
影响因子：
4.8
通讯作者：
Pantaloni, D
中科院分区：
文献类型：
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作者：
Carlier, MF;Nioche, P;Pantaloni, D
Wiskott-Aldrich综合征蛋白(Wiskott-Aldrich syndrome Protein，WASP)家族的蛋白质连接信号通路到肌动蛋白聚合驱动的细胞运动，黄蜂N-WASP是一种广泛存在的同源物，它通过其C-末端WA结构域与Arp2/3复合体和G-肌动蛋白相互作用来刺激肌动蛋白聚合，N-WASP的活性通过结合效应分子如CDC42-鸟苷5‘-3-O-(硫代)三磷酸、磷脂酰肌醇二磷酸或志贺氏菌ICSA蛋白而增强。在这里，我们证明了SH3-SH2-SH3接头Grb2是N-黄蜂的另一个激活剂，它通过增加N-黄蜂Arp2/3复合体的数量来刺激肌动蛋白聚合，N-黄蜂活性、沉降速度和交联实验的浓度依赖关系表明N-黄蜂经历了自结合，而Grb2通过优先与其活性单体结合来增强N-黄蜂的活性，使用多肽抑制剂、突变的Grb2和分离的SH3结构域，证明Grb2的作用是通过其C-末端SH3结构域与N-黄蜂的富含Pro区域的相互作用而介导的。CDC42和Grb2同时与N-WASP结合并协同促进肌动蛋白的聚合，Grb2缩短了大肠杆菌(ICSA)基于肌动蛋白的重组运动开始之前的延迟。这些结果提示Grb2可能激活受体酪氨酸激酶信号通路下游Arp2/3复合体介导的肌动蛋白聚合。
Proteins of the Wiskott-Aldrich Syndrome protein (WASp) family connect signaling pathways to the actin polymerization-driven cell motility, The ubiquitous homolog of WASp, N-WASp, is a multidomain protein that interacts with the Arp2/3 complex and G-actin via its C-terminal WA domain to stimulate actin polymerization, The activity of N-WASp is enhanced by the binding of effecters like Cdc42-guanosine 5'-3-O-(thio)triphosphate, phosphatidylinositol bisphosphate, or the Shigella IcsA protein. Here we show that the SH3-SH2-SH3 adaptor Grb2 is another activator of N-WASp that stimulates actin polymerization by increasing the amount of N-WASp Arp2/3 complex, The concentration dependence of N-WASp activity, sedimentation velocity and cross-linking experiments together suggest that N-WASp is subject to self-association, and Grb2 enhances N-WASp activity by binding preferentially to its active monomeric form, Use of peptide inhibitors, mutated Grb2, and isolated SH3 domains demonstrate that the effect of Grb2 is mediated by the interaction of its C-terminal SH3 domain with the proline-rich region of N-WASp. Cdc42 and Grb2 bind simultaneously to N-WASp and enhance actin polymerization synergistically, Grb2 shortens the delay preceding the onset of Escherichia coli (IcsA) actin-based reconstituted movement. These results suggest that Grb2 may activate Arp2/3 complex-mediated actin polymerization downstream from the receptor tyrosine kinase signaling pathway.