Boehm J E, Chaika O V, Lewis R E
Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska 68198-6805, USA.
J Biol Chem. 1998 Mar 20;273(12):7169-76. doi: 10.1074/jbc.273.12.7169.
The intracellular mechanisms used by insulin and insulin-like growth factors to block programmed cell death are unknown. To identify receptor structures and signaling pathways essential for anti-apoptotic effects on cells, we have created a chimeric receptor (colony-stimulating factor-1 receptor/insulin receptor chimera (CSF1R/IR)) connecting the extracellular, ligand-binding domain of the colony-stimulating factor-1 (CSF-1) receptor to the transmembrane and cytoplasmic domains of the insulin receptor. Upon activation with CSF-1, the CSF1R/IR phosphorylates itself and intracellular substrates in a manner characteristic of normal insulin receptors. CSF-1 treatment protected cells expressing the CSF1R/IR from staurosporine-induced apoptosis. A chimeric receptor (CSF1R/IRDelta960) with a deletion of 12 amino acids from its juxtamembrane domain was constructed and expressed. CSF-1-treated cells expressing the CSF1R/IRDelta960 are unable to phosphorylate IRS-1 and Shc (Chaika, O. V., Chaika, N., Volle, D. J., Wilden, P. A. , Pirrucello, S. J., and Lewis, R. E. (1997) J. Biol. Chem. 272, 11968-11974). CSF-1 stimulated glucose uptake, mitogen-activated protein kinases, and IRS-1-associated phosphatidylinositol 3' kinase in cells expressing the CSF1R/IR but not in cells expressing the CSF1R/IRDelta960. Surprisingly, the CSF1R/IRDelta960 was as effective as the CSF1R/IR in mediating CSF-1 protection of cells from staurosporine-induced apoptosis. These observations indicate that the anti-apoptotic effects of the insulin receptor cytoplasmic domain can be mediated by signaling pathways distinct from those requiring IRS-1 and Shc.
胰岛素和胰岛素样生长因子用于阻止程序性细胞死亡的细胞内机制尚不清楚。为了确定对细胞抗凋亡作用至关重要的受体结构和信号通路，我们构建了一种嵌合受体（集落刺激因子-1受体/胰岛素受体嵌合体（CSF1R/IR）），将集落刺激因子-1（CSF-1）受体的细胞外配体结合结构域与胰岛素受体的跨膜和细胞质结构域相连。用CSF-1激活后，CSF1R/IR以正常胰岛素受体特有的方式使自身和细胞内底物磷酸化。CSF-1处理可保护表达CSF1R/IR的细胞免受星形孢菌素诱导的凋亡。构建并表达了一种在其近膜结构域缺失12个氨基酸的嵌合受体（CSF1R/IRDelta960）。表达CSF1R/IRDelta960的CSF-1处理细胞无法使IRS-1和Shc磷酸化（Chaika, O. V., Chaika, N., Volle, D. J., Wilden, P. A., Pirrucello, S. J., and Lewis, R. E. (1997) J. Biol. Chem. 272, 11968 - 11974）。CSF-1刺激表达CSF1R/IR的细胞摄取葡萄糖、激活丝裂原活化蛋白激酶以及与IRS-1相关的磷脂酰肌醇3'激酶，但不刺激表达CSF1R/IRDelta960的细胞。令人惊讶的是，CSF1R/IRDelta960在介导CSF-1保护细胞免受星形孢菌素诱导的凋亡方面与CSF1R/IR一样有效。这些观察结果表明，胰岛素受体细胞质结构域的抗凋亡作用可由不同于需要IRS-1和Shc的信号通路介导。
