Fig. 1.

Assessment of JNK signaling in the presence and absence of p53. Western blot analyses of phospho-JNK and total-JNK were performed using thioglycollate-elicited peritoneal macrophages derived from p53^+/+ and p53^−/− (on apoE^−/− background) mice. JNK activation was achieved by treatment with (A) LPS (10 ng/ml) or (B) TNFα (10 ng/ml) for the indicated times. Densitometric analyses of Western blots normalized to total JNK are shown in the right panels for the indicated times (*P < 0.05). The discrepancy between the number of bands seen on phospho-JNK blots and the total JNK blots likely reflects the variability in the relative abundance of the three JNK subtypes (JNK1, 2, and 3) and their phosphorylation status. JNK, Jun N-terminal kinase; KO, knockout; LPS, lipopolysaccharide; TNF, tumor necrosis factor; WT, wild type.