Polo Like Kinase 3 (PLK3)

CNK is a member of the 'polo' family of serine/threonine kinases. Members of this family have been implicated in cell division and are important in regulating the onset of mitosis and M-phase progression.The predicted 607-amino acid protein has an N-terminal catalytic domain, including an ATP-binding site, a central putative nuclear targeting signal, and a presumed C-terminal regulatory domain. The CNK protein shows homology with several other members of the 'polo' family; it is 91% identical to mouse Fnk, 50% identical to human PLK, 48% identical to Drosophila polo, and 38% identical to S. cerevisiae Cdc5. Northern blot analysis detected expression of a 2.5-kb CNK transcript in a limited number of human tissues, with placenta containing a moderate level and ovary, lung, and peripheral blood leukocytes containing low levels.