IL-7 stimulation induces the activation of JAK/STAT, ras/MAPK, and PI3K/Akt pathways in TAIL7 cells. TAIL7 cells were stimulated with 50 ng/mL IL-7 at 37°C for 15 minutes, or the indicated periods, or left unstimulated (Unst.). (A) Lysates were immunoprecipitated with anti-JAK3 agarose conjugate antiserum, resolved by 10% SDS-PAGE, and immunoblotted with an antiphosphotyrosine mAb (P-Tyr), stripped, and reprobed with anti-JAK3 antiserum. (B) Lysates were resolved by 10% SDS-PAGE and immunoblotted. Phosphorylated STAT5, Erk, and Akt were probed with phospho-specific antibodies. ZAP-70 antibody was used as a loading control. Blot was stripped and sequentially reprobed. P-STAT5 recognizes phosphorylated Y694 and Y699 of STAT5a and STAT5b. P-Erk recognizes phosphorylated Y204 of Erk1 and Erk2. P-Akt recognizes phosphorylated S473 of Akt. Results are representative of 3 independent experiments.