Interleukin 2- and polyomavirus middle T antigen-induced modification of phosphatidylinositol 3-kinase activity in activated T lymphocytes.

摘要: Stimulation of activated T lymphocytes with interleukin 2 (IL-2) results in rapid increases intracellular protein tyrosine phosphorylation. Both the identity kinase (PTK) by IL-2 receptor ligation and identities critical target proteins for this PTK remain largely undefined. In article, we demonstrate that stimulation murine or human cells 10 to 30 min induces two- threefold level phosphatidylinositol (PtdIns) 3-kinase activity present antiphosphotyrosine (p-Tyr) antibody immunoprecipitates from these cells. Furthermore, substantial levels PtdIns were coprecipitated IL-2-deprived antibodies src-related p59fyn. Cellular induced a increase p59fyn-associated activity. To examine effect constitutive on growth factor responsiveness cells, CTLL-2 transfected polyomavirus middle antigen (MTAg) expression vector. Anti-p-Tyr anti-p59fyn MTAg-transfected contained three- sixfold higher than wild-type Immune complex assays revealed MTAg concomitantly p59fyn However, stable did not abrogate dependence exogenous continued proliferation.