Cancer Research UK Growth Factor Signalling Group, School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, United Kingdom.
PLoS One. 2013 Apr 23;8(4):e61513. doi: 10.1371/journal.pone.0061513. Print 2013.
Eps8 is involved in both cell signalling and receptor trafficking. It is a known phosphorylation substrate for two proteins involved in the fibroblast growth factor receptor (FGFR) signalling pathway: the receptor itself and Src. Here we report a differential proteomic analysis of Eps8 aimed to identify specific FGFR and Src family kinase dependent phosphosites and co-associated phosphodependent binding partners. This study reveals a total of 22 Eps8 pTyr and pSer/Thr phosphorylation sites, including those that are dependent on Src family and FGFR kinase activity. Peptide affinity purification of proteins that bind to a selection of the pTyr phosphosites has identified a range of novel Eps8 binding partners including members of the intracellular vesicle trafficking machinery (clathrin and AP-2), proteins which have been shown to regulate activated receptor trafficking (NBR1 and Vav2), and proteins involved in receptor signalling (IRS4 and Shp2). Collectively this study significantly extends the understanding of Eps8 post-translational modification by regulated phosphorylation, identifies novel Eps8 binding partners implicated in receptor trafficking and signalling, and confirms the functions of Eps8 at the nexus of receptor signalling and vesicular trafficking.
Eps8 参与细胞信号转导和受体运输。它是两个参与成纤维细胞生长因子受体 (FGFR) 信号通路的蛋白质的已知磷酸化底物：受体本身和 Src。在这里，我们报告了一项针对 Eps8 的差异蛋白质组学分析，旨在鉴定特定的 FGFR 和 Src 家族激酶依赖性磷酸化位点和共同相关的磷酸化依赖性结合伙伴。这项研究共揭示了 22 个 Eps8 pTyr 和 pSer/Thr 磷酸化位点，包括那些依赖于 Src 家族和 FGFR 激酶活性的磷酸化位点。对与一系列 pTyr 磷酸化位点结合的蛋白质进行肽亲和纯化，鉴定了一系列新的 Eps8 结合伙伴，包括细胞内囊泡运输机制的成员（网格蛋白和 AP-2）、已被证明调节激活受体运输的蛋白质（NBR1 和 Vav2）以及参与受体信号转导的蛋白质（IRS4 和 Shp2）。总之，这项研究极大地扩展了对受调节磷酸化的 Eps8 翻译后修饰的理解，鉴定了参与受体运输和信号转导的新的 Eps8 结合伙伴，并证实了 Eps8 在受体信号转导和囊泡运输的交汇点的功能。
