Extracellular signal-regulated kinase 2 (Erk2) is also known as mitogen activated protein kinase 2, microtubule-associated protein-2 kinase MAP kinase 2, p42-MAPK or EGF receptor T669 (ERT1). Mek2 activates Erk2 by phosphorylation of neighbouring threonine-183 and tyrosine-185 residues. Erk2, a serine-threonine kinase phosphorylates microtubule associated protein-2 and myelin basic protein. This kinase is an important proximal componant of the MAP kinase pathway involved in transmitting the signalsfrom growth factors, neurotransmitters and hormones at the cell surface to the transcriptional events in the nucleus.