Phosphatidylinositol 3-kinase and Src family kinases are required for phosphorylation and membrane recruitment of Dok-1 in c-Kit signaling
Phosphatidylinositol 3-kinase and Src family kinases are required for phosphorylation and membrane recruitment of Dok-1 in c-Kit signaling
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DOI：
10.1074/jbc.m200277200
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发表时间：
2002-04-19
影响因子：
4.8
通讯作者：
Resh, MD
中科院分区：
文献类型：
--
作者：
Liang, XQ;Wisniewski, D;Resh, MD
Dok-1 是一种接头蛋白，是 Bcr-Abl 和其他酪氨酸蛋白激酶的底物。 pleckstrin 同源性和磷酸酪氨酸结合域以及多个酪氨酸磷酸化位点的存在表明 Dok-1 参与蛋白质-蛋白质和/或蛋白质-脂质相互作用。在这里，我们表明，用 c-Kit 配体 (KL) 刺激 Mo7 造血细胞会诱导磷脂酰肌醇 (PI) 3 激酶依赖性酪氨酸磷酸化和 Dok-1 的膜募集。将 K-Ras 膜靶向基序添加到 Dok-1 中生成了组成型膜结合 Dok-1 蛋白，其酪氨酸磷酸化不依赖于 PI 3-激酶。 Dok-1 的膜定位是其发挥细胞增殖负调节作用的能力所必需的。其他实验表明，Dok-1 与 e-Kit 的近膜区域和 C 末端尾部相关。 Lyn 促进 c-Kit 的磷酸化以及 c-Kit 和 Dok-1 的结合。 Lyn 和 Tec 都能够磷酸化 Dok-1。然而，使用正常和 Lyn 缺陷小鼠的原代骨髓肥大细胞表明，Lyn 是 KL 依赖性 Dok-1 酪氨酸磷酸化所必需的。总之，这些数据表明，KL 对 PI 3 激酶的激活促进了 Dok pleckstrin 同源结构域的结合以及 Dok-1 募集至质膜，其中 Dok-1 被 Src 和/或 Tec 家族激酶磷酸化。
Dok-1 is an adaptor protein that is a substrate for Bcr-Abl and other tyrosine protein kinases. The presence of pleckstrin homology and phosphotyrosine binding domains as well as multiple tyrosine phosphorylation sites suggests that Dok-1 is involved in protein-protein and/or protein-lipid interactions. Here we show that stimulation of Mo7 hematopoietic cells with c-Kit ligand (KL) induces phosphatidylinositol (PI) 3-kinase-dependent tyrosine phosphorylation and membrane recruitment of Dok-1. Addition of the K-Ras membrane-targeting motif to Dok-1 generated a constitutively membrane-bound Dok-1 protein whose tyrosine phosphorylation was independent of PI 3-kinase. Membrane localization of Dok-1 was required for its ability to function as a negative regulator of cell proliferation. Additional experiments revealed that Dok-1 associated with the juxtamembrane region and C-terminal tail of e-Kit. Lyn promoted phosphorylation of c-Kit and association of c-Kit and Dok-1. Both Lyn and Tec were capable of phosphorylating Dok-1. However, the use of primary bone marrow mast cells from normal and Lyn-deficient mice demonstrated that Lyn is required for KL-dependent Dok-1 tyrosine phosphorylation. Taken together, these data indicate that activation of PI 3-kinase by KL promotes binding of the Dok pleckstrin homology domain and Dok-1 recruitment to the plasma membrane where Dok-1 is phosphorylated by Src and/or Tec family kinases.