Flagellin activates MAPK signaling pathway in mouse organs. Mitogen-activated protein kinase (MAPK) activation, evaluated by the phosphorylation state of c-jun-NH2 terminal kinase (JNK) and extracellular related kinase (ERK), in mouse organs 30 minutes after the injection of flagellin (1 μg/mouse) or saline (sham). Phosphorylation of JNK was detected in the lung, liver, and gut, but not the kidney. ERK phosphorylation was present in the lung, gut and kidney, but not in the liver. Total JNK and ERK signals were not influenced by flagellin; α-tubulin, loading controls. Blots, shown in duplicates, are representative of at least three independent experiments.