...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Molecular and Cellular Biology >Activation of phospholipase C gamma in Schizosaccharomyces pombe by coexpression of receptor or nonreceptor tyrosine kinases.
【24h】

Activation of phospholipase C gamma in Schizosaccharomyces pombe by coexpression of receptor or nonreceptor tyrosine kinases.

机译：通过共表达受体或非受体酪氨酸激酶激活粟酒裂殖酵母中磷脂酶Cγ的活化。

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The fission yeast Schizosaccharomyces pombe has no detectable endogenous receptor tyrosine kinases or associated signalling apparatus, and we have used this cell system to reconstitute mammalian platelet-derived growth factor beta (PDGF beta) receptor-linked activation of phospholipase C gamma 2 (PLC gamma 2). The PDGF beta receptor migrates as a glycosylated protein of 165 kDa associated exclusively with membrane fractions. No tyrosine autophosphorylation was detected when PDGF beta was expressed alone. PLC gamma 2 appears as a 140-kDa protein distributed between particulate and soluble fractions which exhibits characteristic selectivity for phosphatidylinositol 4,5-bisphosphate and is sensitive to powerful activation by Ca2+. When coexpressed, both PDGF beta and PLC gamma 2 undergo tyrosine phosphorylation, and this is accompanied by a > 26-fold increase in [3H]inositol 4,5-biphosphate ([3H]IP2) and [3H]inositol 1,4,5-triphosphate [3H]IP3 production. Treatment with the tyrosine phosphatase inhibitor pervanadate further increased PLC gamma 2 tyrosine phosphorylation as well as [3H]IP2 and [3H]IP3 generation. Phosphorylated PLC gamma 2 was found predominantly in membrane fractions. To test a nonreceptor tyrosine kinase, we then expressed the human proto-oncogene c-src together with its negative regulator Csk. These were immunodetectable as bands at 60 kDa (c-Src) and 50 kDa (Csk) and distributed between membrane and cytosolic fractions. When yeast coexpressing c-Src, Csk, and PLC gamma 2 was incubated with pervanadate, PLC gamma 2 was tyrosine phosphorylated and [3H]IP2 and [3H]IP3 production increased 11.0- and 7.0-fold, respectively. Csk expressed alone with PLC gamma 2 was ineffective. Similar PLC gamma 2 activation was observed upon in vitro mixing with the extracts expressing either c-Src or the PDGF beta receptor. In summary, this is the first report of a reconstitution of mammalian tyrosine kinase-linked effector activation in yeast cells and also the first demonstration of direct PLC gamma 2 activation by the proto-oncogene c-src. These observations indicate that S. pombe provides a powerful cell system in which to study critical molecular interactions and activities underlying receptor and nonreceptor tyrosine kinase-dependent cell signaling.
机译：裂变酵母粟酒裂殖酵母（Schizosaccharomyces pombe）没有可检测到的内源性受体酪氨酸激酶或相关信号传导装置，我们已使用该细胞系统重构了哺乳动物血小板衍生的生长因子β（PDGF beta）受体相关的磷脂酶Cγ2（PLCγ2 ）。 PDGFβ受体迁移为165 kDa的糖基化蛋白，仅与膜级分相关。当单独表达PDGF beta时，未检测到酪氨酸自磷酸化。 PLC伽马2以140-kDa的蛋白质形式分布在颗粒级分和可溶性级分之间，对磷脂酰肌醇4,5-双磷酸酯具有特征选择性，并且对Ca2 +的强力激活敏感。当共表达时，PDGF beta和PLC gamma 2都经历酪氨酸磷酸化，并且伴随[3H]肌醇4,5-二磷酸（[3H] IP2）和[3H]肌醇1,4， 5-三磷酸[3H] IP3的生产。酪氨酸磷酸酶抑制剂过氧钒酸盐的处理进一步增加了PLCγ2酪氨酸的磷酸化以及[3H] IP2和[3H] IP3的产生。磷酸化的PLCγ2主要存在于膜级分中。为了测试非受体酪氨酸激酶，我们然后表达了人类原癌基因c-src及其负调节剂Csk。这些被检测为60 kDa（c-Src）和50 kDa（Csk）的条带，并分布在膜部分和胞质部分之间。当将共表达c-Src，Csk和PLCγ2的酵母与过氧钒酸盐孵育时，酪氨酸磷酸化了PLCγ2，[3H] IP2和[3H] IP3的产量分别增加了11.0倍和7.0倍。仅用PLCγ2表达的Csk无效。与表达c-Src或PDGFβ受体的提取物进行体外混合后，观察到类似的PLCγ2活化。总之，这是在酵母细胞中重组哺乳动物酪氨酸激酶相关的效应子激活的第一个报道，也是首次通过原癌基因c-src直接激活PLCγ2的证明。这些观察结果表明，粟酒裂殖酵母提供了强大的细胞系统，可在其中研究关键的分子相互作用和受体和非受体酪氨酸激酶依赖性细胞信号传导基础的活性。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
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