Insulin activation of protein kinase C: a reassessment

摘要: Although insulin is known to activate several protein serine/threonine kinases, its ability kinase C remains controversial. We reinvestigated this question, taking advantage of technical advances such as the development fibroblast cell lines that overexpress normal human receptors, and antibodies expression vectors for myristoylated, alanine-rich substrate (MARCKS) protein, a major cellular C. In HIR 3.5 cells, mouse 3T3 derivative expresses about 6 x 10(6) receptors/cell, (70 nM 10 min) stimulated phosphorylation MARCKS by approximately 2-fold (p less than 0.005). This was not further increased different times exposure, concentrations, or longer periods serum deprivation. The stimulation represented 14% response phorbol 12-myristate 13-acetate 17% 10% fetal calf serum. No significant seen in four other insulin-sensitive lines, which kinases: HIRC-B, BC3H-1, 3T3-L1 adipocytes, H35 rat hepatoma cells made stably express protein. these and/or exerted large stimulatory effect on phosphorylation. conclude may minor extent certain types vastly receptors; however, we believe unlikely be physiological importance.