MEK1 (MAP2K1)
(Mitogen-Activated Protein Kinase Kinase 1 (MAP2K1))
Alternative Name
Mek1 (MAP Kinase Kinase)
Background
MEK1 is one of the MEKs that are upstream of the MAPK ERK1/2. MEK1 is a dual-specific protein kinase that phosphorylates ERK1/2 on boththreonine and tyrosine residues in the sequence TEY. Phosphorylation of these residues dramatically activates ERK1/2, which then phosphorylate their downstream substrate. MEK1 contains 393 amino acids and has a calculated molecular weight of 43,470. MEK1 itself is regulated by phos-phorylation by one of the MEK kinases.