TWO-DIMENSIONAL ANALYSIS OF INTERLEUKIN 2-REGULATED TYROSINE KINASE ACTIVATION MEDIATED BY THE P70-75 BETA-SUBUNIT OF THE INTERLEUKIN-2 RECEPTOR

  • 25 July 1989
    • journal article
    • research article
    • Vol. 264  (21) , 12562-12567
Abstract
The proliferation of activated T lymphocytes is dependent on the interaction of the polypeptide growth factor interleukin 2 (IL 2) with its heterodimeric receptor, which consists of a p55 .alpha. subunit and a p70-75 .beta. subunit. Previously, it was shown that IL 2 stimulates rapid serine phosphorylation of several membrane and cytysolic proteins. Here, using anti-phosphotyrosine antibodies to purify phosphotyrosyl proteins and two-dimensional gel analysis, we show that IL 2 stimulates rapid tyrosine phosphorylation of a variety of cellular proteins, including pp180, pp92, and pp42 in activated human T lymphocytes. In addition, we have examined IL 2-induced tyrosine phosphorylation in the human cell line YT2C2 which expresses mostly the .beta. subunit of the IL 2 receptor and the gibbon cell line MLA-144 which expresses only the .beta. subunit. In both these cell lines, IL 2 induced tyrosine phosphorylation of the same proteins phosphorylated in normal human T lymphocytes in response to IL 2. We conclude that the .beta. subunit is sufficient to induce tyrosine phosphorylation of the normal cellular target substrates involved in signal transduction.