Ras-induced serine phosphorylation of the focal adhesion protein paxillin is mediated by the Raf-->MEK-->ERK pathway.
Ras-induced serine phosphorylation of the focal adhesion protein paxillin is mediated by the Raf-->MEK-->ERK pathway.
复制标题
Ras 诱导的粘斑蛋白桩蛋白丝氨酸磷酸化是由 Raf-->MEK-->ERK 途径介导的。
DOI：
10.1016/s0014-4827(03)00122-8
复制
发表时间：
2003
影响因子：
3.7
通讯作者：
McMahon,Martin
中科院分区：
文献类型：
--
作者：
Woodrow,MelissaA;Woods,Douglas;Cherwinski,HollyM;Stokoe,David;McMahon,Martin
经 Ras 和 Raf 转化的细胞在细胞形态、粘附和细胞内结构方面表现出巨大的变化。因此，我们研究了 Ras 或 Raf 是否可能影响已知参与粘着斑复合物的组装和完整性的蛋白质的行为，而粘着斑复合物在许多这些过程中发挥着至关重要的作用。我们在多种细胞类型中鉴定了 Raf 诱导的接头蛋白桩蛋白丝氨酸磷酸化。 Raf 诱导的桩蛋白丝氨酸磷酸化对桩蛋白酪氨酸磷酸化没有影响，并且无论细胞是否贴壁或维持在悬浮液中都会发生。确定了两个丝氨酸磷酸化位点——S126 和 S130。这些丝氨酸突变为丙氨酸，无论是单独还是组合，都会抑制 Raf 诱导桩蛋白磷酸化的能力。这些数据表明桩蛋白是 Ras 激活的 Raf→MEK 通路下游磷酸化的靶标。然而，我们没有证据表明 ERK1/2 是负责 Raf 诱导桩蛋白磷酸化的激酶。此外，在哺乳动物细胞中激活 Raf→MEK→ERK 途径或表达 S126A/S130A 形式的桩蛋白后，我们没有检测到桩蛋白与多种粘着斑蛋白的结合发生任何变化。
Cells transformed by Ras and Raf display dramatic alterations in cell morphology, adhesion, and intracellular architecture. Consequently, we investigated whether Ras or Raf might influence the behavior of proteins known to be involved in the assembly and integrity of focal adhesion complexes that play a crucial role in many of these processes. We identified Raf-induced serine phosphorylation of the adaptor protein paxillin in a variety of cell types. Raf-induced paxillin serine phosphorylation had no effect on paxillin tyrosine phosphorylation and occurred regardless of whether cells were attached or maintained in suspension. Two sites of serine phosphorylation—S126 and S130—were identified. Mutation of these serines to alanine, either alone or in combination, inhibited the ability of Raf to induce paxillin phosphorylation. These data indicate that paxillin is a target for phosphorylation downstream of the Ras-activated Raf→MEK pathway. However, we have no evidence to suggest that ERK1/2 are the kinases responsible for Raf-induced paxillin phosphorylation. Furthermore, we did not detect any alterations in the binding of paxillin to a number of focal adhesion proteins following either activation of the Raf→MEK→ERK pathway or expression of the S126A/S130A form of paxillin in mammalian cells.