Anti-apoptotic signaling by a colony-stimulating factor-1 receptor/insulin receptor chimera with a juxtamembrane deletion.
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.
Boehm
J E
JE
Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska 68198-6805, USA.
Chaika
O V
OV
Lewis
R E
RE
D000818:Animals; D017209:Apoptosis; D016466:CHO Cells; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D006224:Cricetinae; D053938:DNA Fragmentation; D004789:Enzyme Activation; D005947:Glucose / Q000378:metabolism; D016173:Macrophage Colony-Stimulating Factor / Q000235:genetics / Q000378:metabolism*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010766:Phosphorylation; D011972:Receptor, Insulin / Q000235:genetics / Q000378:metabolism*; D016186:Receptor, Macrophage Colony-Stimulating Factor / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism*; D017384:Sequence Deletion; D015398:Signal Transduction
D011993:Recombinant Fusion Proteins; D016173:Macrophage Colony-Stimulating Factor; D019869:Phosphatidylinositol 3-Kinases; D011972:Receptor, Insulin; D016186:Receptor, Macrophage Colony-Stimulating Factor; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D005947:Glucose