CK1 gamma 3, Active

CK1gamma3 is a member of the CK1 family of serine/threonine protein kinases which play an important role in diverse cell processes, including DNA replication and repair. CK1gamma3 is a ubiquitously expressed protein kinase found in the nuclei, cytoplasm and membrane fractions of eukaryotic cells (1). CK1gamma3 preferentially phosphorylates acidic substrates using ATP as a phosphate donor. The kinase domain of CKI isoforms have been shown to associate with protein kinase C-potentiated inhibitor protein of 17kDa, called CPI-17 (2). CPI-17 specifically inhibits myosin light chain phosphatase and this effect is potentiated when it is phosphorylated on Thr-38 by protein kinases such as the CK1 isoforms.