Mitogen-activated protein kinase kinase 1 and Mitogen-activated protein kinase kinase 2 (MEK1 (for Mitogen-activated protein kinase kinase 1), MEK2 (for Mitogen-activated protein kinase kinase 2))

Mitogen-activated protein kinase kinase 1 and 2 (commonly abbreviated as MEK1 and MEK2) are closely related dual-specificity protein kinases that occupy a central role in the canonical RAS-RAF-MEK-ERK signal transduction pathway[1][2][5]. Their primary biochemical function is to phosphorylate and activate ERK1 and ERK2—actions that mediate diverse cellular processes including proliferation, differentiation, migration, metabolism, cell cycle progression, and apoptosis[1][3][4][6]. MEK1 and MEK2 are essential for normal embryonic development and tissue homeostasis; they can function with partial redundancy, but complete loss of MEK activity is lethal in certain lineages[3]. Dysregulation of MEK1/2—such as by activating mutations in upstream RAS or BRAF—is implicated in a significant fraction of human cancers, making MEK1/2 validated therapeutic targets. Several inhibitors of MEK have been developed and clinically approved for the treatment of malignant melanoma and other cancers driven by MAPK pathway activation[5].

Other names

MEK1MEK2MAP2K1 (for MEK1)MAP2K2 (for MEK2)MAPKK1 (for MEK1)MAPKK2 (for MEK2)MAPKKMAP2K

Inhibition of MEK kinase activity (primarily by allosteric, non-ATP competitive modulation) - Blockade of ERK phosphorylation and downstream signal transduction