Apoptosis regulation by interaction of Bcl-2 protein and Raf-1 kinase.
Apoptosis regulation by interaction of Bcl-2 protein and Raf-1 kinase.
复制标题
DOI：
--
复制
发表时间：
1994-09
期刊：
影响因子：
8
通讯作者：
Hong-Gang Wang;T. Miyashita;S. Takayama;T. Sato;T. Torigoe;S. Krajewski;S. Tanaka;Hovey L rd;J. Troppmair;U. Rapp
中科院分区：
文献类型：
--
作者：
Hong-Gang Wang;T. Miyashita;S. Takayama;T. Sato;T. Torigoe;S. Krajewski;S. Tanaka;Hovey L rd;J. Troppmair;U. Rapp
Bcl-2蛋白在许多类型的人类肿瘤中过量产生，并抑制由各种刺激（包括化疗药物和γ-辐射）诱导的细胞凋亡。然而，Bcl-2蛋白作用的生化机制仍然是个谜。在这里，我们表明，Bcl-2可以与丝氨酸/苏氨酸特异性Raf-1激酶在哺乳动物造血细胞32D.3和当这两种蛋白质在Sf 9昆虫细胞中使用重组杆状病毒产生的免疫共沉淀。虽然Raf-1缺失突变体的分析表明，蛋白质的C-末端的一半，其中包含催化结构域是足够的免疫共沉淀与Bcl-2，Raf-1并没有出现在32 D.3和Sf 9细胞中诱导Bcl-2蛋白的磷酸化。此外，缺乏激酶活性的Raf-1的突变形式仍然可以与Sf 9细胞中的Bcl-2共免疫沉淀，这表明这些蛋白质的相互作用并不反映激酶-底物关系。使用32D.3造血细胞的基因转移实验证明了Bcl-2和Raf-1在抑制生长因子戒断诱导的细胞凋亡方面的功能协同作用。总之，这些观察结果首次在功能上将Bcl-2与信号转导蛋白联系起来，并表明Bcl-2和Raf-1蛋白的相互作用可能是它们在抑制细胞凋亡中合作的能力的原因。
The Bcl-2 protein is over-produced in many types of human tumors and suppresses apoptosis induced by a wide-variety of stimuli, including chemotherapeutic drugs and gamma-irradiation. The biochemical mechanism of action of the Bcl-2 protein however remains enigmatic. Here we show that Bcl-2 can be co-immunoprecipitated with the serine/threonine-specific Raf-1 kinase both in a mammalian hemopoietic cell 32D.3 and when the two proteins are produced in Sf9 insect cells using recombinant baculoviruses. Though analysis of Raf-1 deletion mutants suggested that the C-terminal half of the protein which contains the catalytic domain is sufficient for co-immunoprecipitation with Bcl-2, Raf-1 does not appear to induce phosphorylation of Bcl-2 protein in 32D.3 and Sf9 cells. Furthermore, a mutant form of Raf-1 that lacks kinase activity could still be co-immunoprecipitated with Bcl-2 in Sf9 cells, suggesting that the interaction of these proteins does not reflect a kinase-substrate relation. Gene transfer experiments using 32D.3 hemopoietic cells demonstrated functional synergy between Bcl-2 and Raf-1 with regards to suppression of apoptosis induced by growth factor withdrawal. Taken together, these observations for the first time functionally link Bcl-2 to a signal transducing protein and suggest that the interaction of the Bcl-2 and Raf-1 proteins may be responsible for their ability to cooperate in the suppression of apoptosis.