Mitogen-activated protein kinases (MAPKs) are proline-directed serine and threonine protein kinases that regulate numerous physiological and pathophysiological cell responses. p38 MAPKs belong to a class that plays an important role during inflammatory processes, and their expression is upregulated by inflammatory and stress stimuli (cytokines, ultraviolet irradiation, osmotic and heat shock). p38 MAPKs are also involved in autophagy, apoptosis, cell differentiation, and are implicated in the regulation of inflammatory mediators levels such as tumor necrosis factor-(TNF- and cyclooxygenase-2 (COX-2). Accumulating evidence suggests that p38 MAPKs play an important role in arthritis, and inflammation of the liver, kidney, brain, and lung. Diseases induced by chronic inflammation, including gastritis, colitis, dermatitis, rheumatoid arthritis, pulmonary diseases and type II diabetes affect millions of people every year. Therefore, p38 is an important target in better understanding of inflammation and development of novel treatments. p38 MAPK is activated following phosphorylation at Thr180/Tyr182 by upstream MKK6 and MKK3 kinases. While in quiescent cells p38 localizes to both nucleus and cytosol, stress induced conformational changes within the active site result in selective translocation of activated-p38 into the nucleus. Thus, the selective nuclear accumulation of p38 could be a mechanism to facilitate the phosphorylation of p38 MAPK nuclear targets. Assay Genie's Phospho-p38 MAPK (Thr180+Tyr182) Translocation Assay Kit (Cell-Based) provides a valuable tool to detect the nuclear translocation of activated p38 in fixed mammalian cells.

Figure: Thrombin-induced activation and translocation of Phopho-p38 MAPK (Thr180/Tyr182) in J774 macrophages. J774 cells were seeded into a 96-well plate at 3 X104 cells/well and cultured overnight followed by a 24 hr treatment with either vehicle (A) or Thrombin diluted 1:100 directly into the well (B). Subsequently, cells were processed according to the provided protocol. Translocation of phosphorylated-p38 from cytoplasm to nuclei upon stimulation by Thrombin is apparent with DAPI staining (C) and merged images (D).