The mitogen-activated protein (MAP) kinase cascade participates in the Ras signal transduction pathway. The MAP kinase cascade consists of MEK kinase (Raf-1 or B-Raf), MAP/ERK kinase (MEK1 or MEK2), and extracellular-regulated protein kinase (ERK1 or ERK2). Raf becomes activated following its interaction with Ras-GTP (activated Ras). Via phosphorylation reactions, Raf activates MEK which, in turn, activates ERK. MEK5, also known as MAP Kinase 5, is a 50 kDa protein that is 40% identical to MEK1 and MEK2. Alternative splicing results in two MEK5 isoforms: α (50 kDa) and β (40 kDa). MEK5β has been reported to be ubiquitously expressed while MEK5α is expressed primarily in the liver and brain. The N-terminal amino acid sequence of MEK5α resembles sequences found in actin cytoskeletal proteins, indicating that MEK5α may associate with the cytoskeleton. However, the role of MEK5 in the MAP kinase pathway and its substrate remain to be identified.
This antibody is routinely tested by western blot analysis. Other applications were tested at BD Biosciences Pharmingen during antibody development only or reported in the literature.