首页> 外文期刊>Cellular Signalling >Intracellular signalling pathways of okadaic acid leading to mitogenesis in Rat1 fibroblast overexpressing insulin receptors: okadaic acid regulates Shc phosphorylation by mechanisms independent of insulin.
【24h】

Intracellular signalling pathways of okadaic acid leading to mitogenesis in Rat1 fibroblast overexpressing insulin receptors: okadaic acid regulates Shc phosphorylation by mechanisms independent of insulin.

机译:冈田酸的细胞内信号传导途径导致过表达胰岛素受体的Rat1成纤维细胞发生有丝分裂:冈田酸通过独立于胰岛素的机​​制调节Shc磷酸化。

获取原文
获取原文并翻译 | 示例
           

摘要

Okadaic acid is a powerful inhibitor of serine/threonine protein phosphatases 1 and 2A. Although it is known as a potent tumour promoter, the intracellular mechanism by which okadaic acid mediates its mitogenic effect remains to be clarified. We investigated the effect of okadaic acid on the activation of mitogenesis in Rat1 fibroblasts overexpressing insulin receptors. As previously reported, insulin induced Shc phosphorylation, Shc-Grb2 association, MAP kinase activation, and BrdU incorporation. Okadaic acid also stimulated tyrosine phosphorylation of Shc and its subsequent association with Grb2 in a time- and dose-dependent manner without affecting tyrosine phosphorylation of insulin receptor beta-subunit and IRS. However, to a lesser extent, okadaic acid stimulated MAP kinase activity and BrdU incorporation. Interestingly, preincubation of okadaic acid potentiated insulin stimulation of tyrosine phosphorylation of Shc (213% of control), Shc-Grb2 association (150%), MAP kinase activity (152%), and BrdU incorporation (148%). These results further confirmed the important role of Shc, but not IRS, in cell cycle progression in Rat1 fibroblasts. Furthermore, serine/ threonine phosphorylation appears to be involved in the regulation of Shc tyrosine phosphorylation leading to mitogenesis by mechanisms independent of insulin signalling.
机译:冈田酸是一种强大的丝氨酸/苏氨酸蛋白磷酸酶1和2A抑制剂。尽管它被称为有效的肿瘤启动子,但冈田酸介导其促有丝分裂作用的细胞内机制仍有待阐明。我们研究了冈田酸对过表达胰岛素受体的Rat1成纤维细胞中有丝分裂活化的影响。如先前报道,胰岛素诱导Shc磷酸化,Shc-Grb2关联,MAP激酶激活和BrdU纳入。冈田酸还以时间和剂量依赖性方式刺激Shc的酪氨酸磷酸化及其随后与Grb2的缔合,而不影响胰岛素受体β亚基和IRS的酪氨酸磷酸化。但是,冈田酸在较小程度上刺激MAP激酶活性和BrdU掺入。有趣的是,冈田酸的预孵育增强了胰岛素对Shc酪氨酸磷酸化的刺激作用(对照组的213%),Shc-Grb2缔合(150%),MAP激酶活性(152%)和BrdU掺入(148%)。这些结果进一步证实了Shc(而非IRS)在Rat1成纤维细胞的细胞周期进程中的重要作用。此外,丝氨酸/苏氨酸的磷酸化似乎参与了Shc酪氨酸磷酸化的调节,从而通过独立于胰岛素信号传导的机制导致了有丝分裂。

著录项

相似文献

  • 外文文献
  • 中文文献
获取原文

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号