Kinase Group CK1

Kinase Classification: CK1 Group

The CK1 group (Cell Kinase 1, originally known as Casein Kinase 1) is a small group of kinases that are very similar to each other in sequence, but very distinct from other kinase groups. Structural comparisons show CK1s to be the most divergent of ePKs, and several conserved ePK motifs are modified in CK1s: for instance, the APE motif becomes a SIN.

KinBase search for CK1 kinases.

Families within the CK1 group

CK1

This is the largest family, with several subfamilies, and is found across all eukaryotes.

VRK

Vaccinia Related Kinase, named after a homolog found in vaccinia virus and other poxvididae. Also found within all metazoans, 3 members in vertebrates, of which one (VRK3) is a pseudokinase and possible phosphatase regulator.

TTBK

Tau-Tubulin Kinase in human is neuronal-specific and known to phosphorylate tau with a possible role in amyloidogenesis. Homologs are found across unikonts, though apparently lost in nematodes, though nematodes have a large expansion of a somewhat distinct family, TTBKL.

TTBKL

TTBK-like kinases found only in nematodes.

Other Nematode-specific CK1 families

A large expansion of the CK1 group is seen in C. elegans, of which most were clustered into several new nematode-specific families: Worm7-11, and Dual (which have two kinase domains per protein). These are generally very poorly studied. The TTBKL family is also a large expansion which is unique to nematodes.