Kinase Subfamily MK2
Kinase Classification: Group CAMK: Family MAPKAPK: Subfamily MK2
Evolution
MK2 is found throughout the metazoa, but nowhere else. It includes two vertebrate genes (MAPKAPK2 and MAPKAP3), a single fly homolog (MAPk-Ak2) and two in worms (C44C8.6/mak-2, K08F8.1).
Domain Structure
Like other family members, MK2 has a central kinase domain with relatively short N- and C-terminal extensions, which may contain targeting motifs, but no defined domains.
Functions
Like other MAPKAPK family members, MK2s are MAPK substrates. Human MAPKAPK2 is a substrate of the p38, and in turn phosphorylates HSP27 (as does MK5), and regulates stress responses, nuclear export, gene expression and cell growth, while MAPKAPK3 is activated by Erk, p38, and Jnk, and includes the tissue-specific transcription factor E47 as a substrate. The single Drosophila homolog responds only to stress MAPKs (p38/Jnk). mak-2 in C. elegans is downstream of DLK-1 kinase (an MLK) and mediates changes in mRNA stability in neuronal development.
