Casein Kinase 1 Gamma 1 (CSNK1g1)

Casein kinase I is the most abundant serine/threonine kinase in eukaryotic cell extracts. Multiple isoforms of the enzyme exist. The gamma-1 isoform is involved in growth and morphogenesis of eukaryotic cells.

Gain-of-function and loss-of-function experiments showed that CSNK1G1 is both necessary and sufficient to transduce LRP6 signaling in vertebrates and Drosophila cells. In Xenopus embryos, CSNK1G1 was required during anterio-posterior patterning to promote posteriorizing Wnt/beta-catenin signaling. CSNK1G1 is associated with LRP6, which has multiple, modular CK1 phosphorylation sites. Wnt treatment induced the rapid CK1-gamma-mediated phosphorylation of these sites within LRP6, which, in turn, promoted the recruitment of the scaffold protein Axin.