p38 mitogen-activated protein kinase (MAPK) is a member of the serine-threonine MAPK family that triggers many cellular processes including cell cycle, development, and apoptosis. These kinases are activated by environmental stress signals such as osmotic shock, infection, and cytokines causing phosphorylation of p38 MAPK. This results in a phosphorylation cascade, activating transcription factors, and inducing gene expression. p38 MAPK is widely expressed in heart, brain, skeletal muscle, platelets, and immune cells. Due to this distribution, p38 MAPK plays a role in cardiovascular disease, arthritis, and cancer. It is mainly present in the cytosol, but can also be found in the nucleus after activation. Based on the amino acid sequence, the expected molecular weight of this protein is 41 kDa.
