MAPKAPK

The MAPKAPK group comprises MAPK-activated protein kinases, serine/threonine kinases that function as downstream relays of p38 and ERK mitogen-activated protein kinase cascades. The upstream MAPKs phosphorylate a conserved activation-loop motif, switching on MK2, MK3, MK5, and the MNKs. These kinases then phosphorylate substrates controlling inflammation and translation, including heat shock protein 27, the mRNA-destabilizing protein tristetraprolin, and the cap-binding factor eIF4E. Consequently they regulate tumor necrosis factor and interleukin production, stress-fiber formation, and selective mRNA translation under stress. MK2 inhibitors have entered development for inflammatory disease, while MNK inhibition is being explored in oncology, illustrating the therapeutic relevance of this group.