MEK1- MAP Kinase Kinase (MAPKK)

The mitogen-activated protein (MAP) kinase pathway has been implicated in the actions of many cellular processes including hormones, growth factors and oncogene products (1,2). The mitogen-activated protein kinase kinase 1 (MEK1 or MAPKK1) is one of the three isoforms of the protein serine/threonine kinase family. The mechanism of MEK1 activation involves protein phosphorylation specifically on serine 218 and 222 by MEK kinase (MEKK) or by autophosphorylation (3,4). Activation of MEK1 in vivo was also demonstrated through the inhibition of serine/threonine phosphayases by SV40 smal T antigen, an inhibitor of phosphatase PP2A (5). Oncogene products including Raf, Tpl-2 and Ras have been demonstrated to be involved in mediating MEK1 activity (6).
This His tagged recombinant MEK1 is expressed in baculovirus system and purified by an affinity chromatography in combination with FPLC chromatography.
Recombinant MEK1 (1-393) can be used for in vitro phosphorylation or dephosphorylation assays.
Purified protein is greater than 95% homogeneous.
1 unit equals 1 nanogram of purified protein.
0.5 mg/ml (in 1X dilution buffer A)
1X dilution buffer A: 20 mM Tris-Cl (pH 8.0), 20% Glycerol, 100 mM KCl, 0.2 mM EDTA and 1 mM DTT.
 
References:
1. Davis, RJ. (1993) J. Biol. Chem. 268, 14553-14556
2. Robbins, DJ. et al., (1994) Adv. Cancer Res. 63, 93-116
3. Xu, S. et al., (1995) Proc. Natl. Acad. Sci. USA 92, 6808-6812
4. Ahn, NG. et al., (1993) Proc. Natl. Acad. Sci. USA 90, 5143-5147
5. Sontag, E. et al., (1993) Cell 75, 887-897
6. Rajalingam, K. et al., (2005) Nat. Cell Biol. 7, 837-843