FIGURE 3.

OPN-dependent PDLIM2 Ser-137 phosphorylation and STAT1. a, functional role of LPS-dependent PDLIM2 Ser-137 phosphorylation was determined in the context of STAT1 degradation using PDLIM2-S137A as an antagonist or PDLIM2-S137D as an agonist. Immunoblot analysis was performed using RAW cells to measure total cellular and phosphorylated nuclear STAT1 (P-STAT1) in the presence and absence of LPS. In selected instances, cells were transfected with PDLIM2-S137A, PDLIM2-S137D, and/or siRNA OPN prior to LPS stimulation. Blot is representative of three experiments. b, IP studies were performed to assess the extent of Ub-associated P-STAT1 in the presence of cycloheximide (10 μg/ml) and MG132 (10 μm). Cell lysates (500 μg) were immunoprecipitated with P-STAT1 Ab and immunoblotted (IB) with anti-Ub Ab. In selected instances, cells were transfected with PDLIM2-S137A, PDLIM2-S137D, and/or siRNA OPN prior to LPS stimulation. Immunoblot analysis for P-STAT1 was performed as a control. Blot is representative of three experiments.