Mitogen-activated protein kinase 13 (MAPK13)

Mitogen-activated protein kinase 13 (MAPK13), commonly referred to as p38 delta, is a serine/threonine kinase and a member of the p38 MAPK family, encoded by the MAPK13 gene. It integrates diverse cellular signals related to inflammation and stress, leading to activation of specific transcription factors and modulation of cellular actions such as proliferation, differentiation, and apoptosis. MAPK13 is activated by proinflammatory cytokines and stress stimuli. Downstream substrates include transcription factor ATF2, microtubule regulator stathmin, and activator MYB[1][4][5]. MAPK13 has tissue- and context-specific roles distinct from other p38 isoforms, particularly in skin differentiation, tumor development, and inflammatory disease. Structural and biochemical studies have elucidated its active and inactive conformations, supporting structure-guided development of selective small molecule inhibitors for research and potential therapeutic use[2][6][8]. MAPK13 is considered a valid therapeutic target in cancer and inflammatory diseases, though no selective inhibitors have been clinically validated. Its function and regulation are areas of ongoing research, particularly given its relatively understudied status compared to other p38 isoforms such as MAPK14 (p38α)[4][5][6].

Other names

p38 delta (p38δ)SAPK4 (stress-activated protein kinase 4)MAP kinase p38 deltap38deltaPRKM13Serk4

Inhibition of kinase activity—most investigated drugs/inhibitors act as ATP-competitive antagonists binding the kinase domain active site in the DFG-out conformation, preventing phosphorylation of downstream proteins[6]. Modulation of stress and inflammatory signaling pathways.