Mitogen-activated protein kinase family (MAPK family) (MAPK)

The Mitogen-activated protein kinase (MAPK) family is a group of evolutionarily conserved serine/threonine-specific protein kinases that play a central role in converting extracellular stimuli into a wide range of cellular responses (UniProt, Wikipedia). The family is primarily composed of three major subfamilies: the extracellular signal-regulated kinases (ERK), the c-Jun N-terminal kinases (JNK), and the p38 MAPKs (PubMed, Sigma-Aldrich). These kinases operate within a hierarchical three-tier signaling module—comprising a MAP kinase kinase kinase (MAPKKK), a MAP kinase kinase (MAPKK), and the MAPK itself—to regulate critical processes such as cell proliferation, differentiation, survival, and apoptosis (NIH). Dysregulation of MAPK signaling is a hallmark of many human diseases, particularly cancer, where hyperactivation of the ERK pathway drives uncontrolled tumor growth (PubMed). In inflammatory diseases, the p38 and JNK pathways are key mediators of the production of pro-inflammatory cytokines like TNF-alpha and IL-1 (StatPearls). Therapeutic intervention targeting the MAPK family involves small-molecule inhibitors that block kinase activity through ATP-competitive or allosteric mechanisms. While several inhibitors targeting upstream components like BRAF and MEK are FDA-approved for oncology, direct inhibitors of ERK, p38, and JNK are currently being evaluated in clinical trials for various indications. Challenges in targeting this family include the development of drug resistance through compensatory pathway activation and significant off-target toxicities such as skin rash and cardiotoxicity (MDPI).

Other names

MAP kinaseMitogen-activated protein kinaseExtracellular signal-regulated kinase (ERK)c-Jun N-terminal kinase (JNK)p38 mitogen-activated protein kinaseStress-activated protein kinase (SAPK)

ATP-competitive inhibition of kinase activity, allosteric inhibition of kinase activity, and prevention of downstream substrate phosphorylation (PubMed, Sigma-Aldrich).