FIGURE 3.

Nef inhibits LPS-induced phosphorylation of JNK, but not ERK MAPKs. 2 × 10⁶ THP-1 cells (left panel) and monocytes (right panel) were infected twice with either pSRα or pSRα-Nef retroviruses followed by LPS stimulation (1 μg/ml) for the indicated times. Total proteins were analyzed for JNK (A) and ERK1/2 (B) phosphorylation by Western blot analysis using anti-phospho-JNK and anti-phospho-ERK1/2 antibodies, respectively. To ensure equal protein loading, the blots were stripped and reprobed with anti-JNK and anti-ERK1/2 antibodies, respectively. Quantitation and normalization as mean densitometry units to the kinase content are shown in the bottom panels. Results shown are a representative of three independent experiments.