Kinase Family Csk

Kinase Classification: Group TK: Family Csk

CSK (C-terminal Src kinase) kinases inactivate Src kinases by phosphorylation of a conserved tyrosine on their C-terminal tail. They have the typical SH2-SH3-Kinase domain architecture of Src sub-group kinases. Unlike other Src subgroup kinases, CSK lack an activation loop phosphorylation site, as well as the inhibitory phosphorylation site on their tail.

Evolution

CSK is found in all animals and a few related lineages (choanoflagellates and filastereans). This is the same distribution as the other Src-subgroup families (Src, Abl, and Tec), suggesting a close functional interaction within this subgroup. CSK is typically single-copy, but vertebrates have two members: CSK and CTK.