Mitogen-activated protein kinase kinase

Mitogen-activated protein kinase kinase (also known as MAP2K, MEK, MAPKK) is a dual-specificity kinase enzyme which phosphorylates mitogen-activated protein kinase (MAPK).

MAP2K is classified as.

There are seven genes:
 * (a.k.a. MEK1)
 * (a.k.a. MEK2)
 * (a.k.a. MKK3)
 * (a.k.a. MKK4)
 * (a.k.a. MKK5)
 * (a.k.a. MKK6)
 * (a.k.a. MKK7)

The activators of p38 (MKK3 and MKK6), JNK (MKK4 and MKK7), and ERK (MEK1 and MEK2) define independent MAP kinase signal transduction pathways. The acronym MEK derives from MAPK/ERK Kinase.

Role in melanoma
MEK is a member of the MAPK signaling cascade that is activated in melanoma. When MEK is inhibited, cell proliferation is blocked and apoptosis (controlled cell death) is induced.