Signal transduction of the human granulocyte-macrophage colony- stimulating factor and interleukin-3 receptors involves tyrosine phosphorylation of a common set of cytoplasmic proteins

摘要: Human granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-3 (IL-3) exert multiple effects on the proliferation, differentiation, function of myeloid lineage cells through their interaction with specific cell-surface receptors. There is a considerable degree overlap in biological these two growth factors, but little known about mechanisms postreceptor signal transduction. We have investigated GM-CSF IL-3 protein tyrosine-kinase activity human cell line, MO7E, which proliferates response to either factor. Tyrosine-kinase was detected using immunoblotting monoclonal antibody (MoAb) for phosphotyrosine. were found induce nearly identical pattern tyrosine phosphorylation both one- two-dimensional gel electrophoresis. Tyrosine cytosolic proteins particular increased more than 10-fold, 93-Kd (pp93) 70-Kd (pp70). pp93 pp70 observed within 1 minute, reached maximum at 5 15 minutes, gradually decreased thereafter. Other 150, 125, 63, 55, 42, 36 Kd also phosphorylated IL-3, although lesser degree. dependent concentration over range 0.1 10 ng/mL 30 ng/mL. Stimulation MO7E 12-0-tetradecanoyl-phorbol-13-acetate (TPA) or cytokines such as G-CSF, M-CSF, interleukin-1 (IL-1), interleukin-4 (IL-4), interleukin-6 (IL-6), interferon gamma, tumor necrosis (TNF), transforming factor-beta (TGF-beta) did not pp70, suggesting that phosphoproteins are GM-CSF-or IL-3-induced activation. The extent duration all substrates by pretreatment vanadate, an inhibitor protein-tyrosine phosphatases. Importantly, culture vanadate (up mumol/L) resulted dose-dependent increase proliferation up 1.8-fold. These results suggest may be important receptor-mediated transduction be, least partially, regulated balance between CSF-induced kinase phosphatase activity.