CNK, a member of the CDC5/Polo subfamily of Ser/Thr protein kinases, is involved in regulating M phase functions during the cell cycle. It may also be part of the signaling network controlling cellular adhesion. In vitro, is able to phosphorylate CDC25C and casein. This membrane-associated protein binds to the calcium/integrin-binding protein (CIB). This interaction probably occurs via the POLO-box domain. Transcripts are highly detected in placenta, lung, followed by skeletal muscle, heart, pancreas, ovaries and kidney and weakly detected in liver and brain. This protein exhibits a short half-live. In cells of hematopoietic origin, CNK is strongly and exclusively detected in terminally differentiated macrophages. Transcript expression appears to be down-regulated in primary lung tumor. Cytokine and cellular adhesion trigger CNK induction. CNK is thought to be phosphorylated as cells enter mitosis and dephosphorylated as cells exit mitosis The protein contains 2 POLO box domains.
Cnk; Cytokine-inducible serine/threonine-protein kinase; FGF-inducible kinase; Fnk; PLK-3; Plk3; Polo-like kinase 3; Proliferation-related kinase; Serine/threonine-protein kinase PLK3