Structural and functional insights into the interaction between the Cas family scaffolding protein p130Cas and the focal adhesion-associated protein paxillin.
Structural and functional insights into the interaction between the Cas family scaffolding protein p130Cas and the focal adhesion-associated protein paxillin.
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Cas 家族支架蛋白 p130Cas 与粘着斑相关蛋白桩蛋白之间相互作用的结构和功能见解。
DOI：
10.1074/jbc.m117.807271
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Zheng,JieJ
中科院分区：
文献类型：
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作者：
Zhang,Chi;Miller,DarcieJ;Guibao,CristinaD;Donato,DominiqueM;Hanks,StevenK;Zheng,JieJ
Cas家族支架蛋白p130 Cas是位于粘着斑（focal adhesion，FA）中的Src底物，并且在整合素信号传导中起作用以促进细胞运动、侵袭、增殖和存活。p130 Cas靶向FA是其酪氨酸磷酸化和下游信号传导所必需的。虽然N-末端SH 3结构域对于p130 Cas定位是重要的，但也有报道C-末端区域参与p130 Cas FA靶向。据报道，p130 Cas或Cas家族同源结构域（CCHD）的C-末端区域采用与粘着斑激酶C-末端粘着斑靶向结构域类似的结构。然而，CCHD促进FA靶向p130 Cas的机制仍不清楚。在这项研究中，使用量热法，我们确定了FA相关蛋白桩蛋白的第一个LD基序（LD 1）作为p130 Cas CCHD的结合配偶体（以1：1的化学计量比，Kd为4.2 μm），并通过X射线晶体学阐明了与桩蛋白LD 1基序复合的p130 Cas CCHD的结构。值得注意的是，将CCHD/LD 1复合物与先前解析的CCHD与含SH 2的蛋白质NSP 3复合物的结构进行比较，发现LD 1相对于NSP 3具有几乎相同的关键疏水性和酸性残基定位。由于桩蛋白是脂肪酸的关键支架分子之一，我们认为p130 Cas CCHD和桩蛋白的LD 1基序之间的相互作用在p130 Cas脂肪酸靶向中起着重要作用。
The Cas family scaffolding protein p130Cas is a Src substrate localized in focal adhesions (FAs) and functions in integrin signaling to promote cell motility, invasion, proliferation, and survival. p130Cas targeting to FAs is essential for its tyrosine phosphorylation and downstream signaling. Although the N-terminal SH3 domain is important for p130Cas localization, it has also been reported that the C-terminal region is involved in p130Cas FA targeting. The C-terminal region of p130Cas or Cas family homology domain (CCHD) has been reported to adopt a structure similar to that of the focal adhesion kinase C-terminal focal adhesion-targeting domain. The mechanism by which the CCHD promotes FA targeting of p130Cas, however, remains unclear. In this study, using a calorimetry approach, we identified the first LD motif (LD1) of the FA-associated protein paxillin as the binding partner of the p130Cas CCHD (in a 1:1 stoichiometry with aKd∼4.2 μm) and elucidated the structure of the p130Cas CCHD in complex with the paxillin LD1 motif by X-ray crystallography. Of note, a comparison of the CCHD/LD1 complex with a previously solved structure of CCHD in complex with the SH2-containing protein NSP3 revealed that LD1 had almost identical positioning of key hydrophobic and acidic residues relative to NSP3. Because paxillin is one of the key scaffold molecules in FAs, we propose that the interaction between the p130Cas CCHD and the LD1 motif of paxillin plays an important role in p130Cas FA targeting.