Tec is activated in erythroid cells and complexes with various proteins following SCF addition.
(A, B) Tec was immunoprecipitated from F36P, Mo7e, and TF-1 cells incubated with SCF (S; 5 minutes), EPO, or GM-CSF (E, GM; 10 minutes) at 37°C. The immunoprecipitates (15 × 106 cells each) were analyzed by Western blotting with antiphosphotyrosine (PY99; top panels) and anti-Tec (middle panels). Tec precipitates from F36P cells were also analyzed with anti-Lyn (middle panel). As a control, whole cell lysates were analyzed with antiphosphotyrosine (lower panels). Tec is specifically phosphorylated by SCF and complexes with cKit and proteins of 56, 62, and 140 kd, following SCF addition (indicated by arrows). Co-precipitating p62 in SCF-stimulated TF-1 cells is marked with an asterisk.
