This Mitogen-activated protein kinase (MAP kinase) fragment has a peptide sequence of Lys-Tyr-Ile-His-Ser-Ala-Asn-Val-Leu. The MAP kinases are serine/threonine-specific protein kinases belonging to the CMGC (CDK/MAPK/GSK3/CLK) kinase group.

MAPK pathways are a collection of protein signaling cascades stimulated by a wide variety of extracellular signals, including growth factors, cytokines, and environmental stresses. Upon activation, MAPK pathways regulate many fundamental cellular functions, includ-ing differentiation, proliferation, and apoptosis, through the activation of specific transcription factors and other regulatory proteins. MAPKs are involved in directing cellular responses to a diverse array of stimuli, such as mitogens, osmotic stress, heat shock, and proinflammatory cytokines. MAPK proteins have been repeatedly implicated in the pathogenesis of cancer and autoimmune diseases, leading to their selection as targets for drug development.