Fig. 6.
Effect of proteasome pathway inhibitor MG-132 on the degradation of phospho-STAT4 protein.
Activated T cells were cultured with the inhibitor MG-132 (10 nM) or the solvent dimethyl sulfoxide (DMSO) for 1 hour and then cultured with or without cytokines as indicated for 6 hours. Whole-cell extracts were prepared. (A) Western blots were probed with anti-STAT4 (top panel). The membrane was reprobed with anti-STAT1 (middle panel) and anti–phospho-STAT1 (bottom panel). (B) STAT4 protein was immunoprecipitated with anti-STAT4 antibody. The Western blot was probed with anti-STAT4 (top panel) and reprobed with antiphosphotyrosine antibody (bottom panel).
