mitogen activated protein kinase kinase 3 (MAP2K3, MAPK/ERK kinase 3, MEK3, PRKMK3)

Function

• MAP2K3 & MAP2K6 activate p38MAPKs
• dual specificity kinase
• activated by cytokines & environmental stress in vivo
• catalyzes concomitant phosphorylation of Thr & Tyr in MAP kinase p38
• binds to DYRK1B/MIRK & increases its kinase activity
• part of a complex with MAP3K3, RAC1 & CCM2
• interacts with Yersinia yopJ
• activated by dual phosphorylation on Ser-218 & Thr-222
• autophosphorylated
• phosphorylation on Ser-218 & Thr-222 by MEK kinases regulates positively the kinase activity
• Yersinia yopJ may acetylate Ser/Thr residues, preventing phosphorylation & activation, thus blocking the MAPK signaling pathway

ATP + a protein <--> ADP + a phosphoprotein

Structure

• belongs to the protein kinase superfamily, STE Ser/Thr protein kinase family, MAP kinase kinase subfamily
• contains 1 protein kinase domain

Alternative splicing

named isoforms=3

Expression

• abundant expression in skeletal muscle
• widely expressed in other tissues

Pathology

defects in MAP2K3 may be involved in colon cancer

More general terms

• MAP2K/MEK

Database

• UniProt: http://www.uniprot.org/uniprot/P46734.html
• OMIM: https://mirror.omim.org/entry/602315
• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=5606