Binding of src-like Kinases to the β-Subunit of the Interleukin-3 Receptor

摘要: We have previously shown that stimulation of 32D cl3 cells with interleukin (IL)-3 results in the activation three src-like tyrosine kinases, fyn, hck, and lyn. The beta subunit IL-3 receptor co-immunoprecipitated hck lysates both unstimulated IL-3-stimulated cells; however, did not precipitate either fyn or association these kinases was further investigated using bacterial fusion proteins encoding unique, SH3, SH2 domains kinases. Fusion bound to a 150-kDa tyrosine-phosphorylated protein present cells. This identified as by immunoblotting an anti-beta antibody. Glutathione S-transferase (GST) containing domain although amount alone only 30% which domains. indicates is one motifs involved binding subunit. A GST 236-amino acid region cytoplasmic tail subunit, contained four residues, fyn. Binding dramatically increased when GST-beta tyrosine-phosphorylated. Far Western blot analysis used demonstrate this subunit; phosphorylation unique probes. These data indicate mediated phosphotyrosine-dependent -independent mechanisms.