Figure 5.

Rapid GR-dependent effect of dexamethasone on the phosphorylation of LC1. A549 cells were treated with 1 μM dexamethasone for the indicated times in the presence and absence of 10 μM RU486. LC1 immunoprecipitates from total cell lysates were evaluated for phosphorylation status by Western blotting with anti-phosphoserine (PS), anti-phosphothreonine (PT) or anti-phosphotyrosine (PY20) antibodies. Total LC1 expression was evaluated by blotting with anti-LC1. The phosphorylation of Ser, Thr and Tyr residues was increased approximately 4 fold at all times. The effects of dexamethasone on LC1 phosphorylation status were reversed by RU486 at all time points. The expression of LC1 was not significantly changed after 5 and 10 min of dexamethasone (DEX) treatment but was increased approximately 2 fold after 3 h. This effect was also reversed by RU486.