SAPKK3, active, Recombinant, Human (Stress-activated Protein Kinase Kinase 3, SAPK Kinase 3, SAPKK-3

Mitogen-activated protein (MAP) kinases are activated by dual phosphorylation on threonine and tyrosine residues. The activation is carried out by the family of enzymes known as MAP Kinase Kinases (SKKs, MKKs or MEKs). There are at least four distinct SKKs/MKKs/MEKs identified in mammalian cell types: MKK1/MKK2 that activates Erk1/Erk2, MKK3 that activates Mpk2/p38 MAPK, MKK4 that activates p38 and Jun kinase, and MKK5 that activates ErkK5/BMK1. A newly described SKK/MKK has been termed SKK3/MKK6 or MEK6. SKK3/MKK6 is closely related to MKK3 and selectively phosphorylates p38. However, unlike the previously described SKKs/MKKs/MEKs, SKK3/MKK6 exists in a variety of alternatively spliced isoforms and unlike MKK4 is not regulated by rac or Cdc42. Recombinant MKK6/SKK3, residues 4-end, containing an N-terminal maltose binding protein tag, expressed in E.coli. , Specific Activity: , 1940U/mg, where one unit of MKK6 activity is defined as the amount of MKK6 which activates 2uM unactive SAPK2a by 1 unit per minute at 30°C using 100uM ATP. Unit Definition: One unit of SAPK2a activity is defined as 1nmole of phosphate incorporated into 0.33mg/ml myelin basic protein/minute at 30°C with a final ATP concentration of 100uM. In Vitro Kinase Assay: SKK3/MEK6 phosphorylated and activated unactive SAPK2a/p38a in vitro. MBP was used as a substrate to assess activation of SAPK2a/p38a. Storage and Stability: Aliquot to avoid repeated freezing and thawing and store at -70°C. Aliquots are stable for 6 months after receipt. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.