Serine/threonine-protein kinase that plays a central role in centriole duplication. Able to trigger procentriole formation on the surface of the mother centriole cylinder, using mother centriole as a platform, leading to the recruitment of centriole biogenesis proteins such as sas-6. When overexpressed, it is able to induce centrosome amplification through the simultaneous generation of multiple procentrioles adjoining each parental centriole during S phase. Centrosome amplification following overexpression can initiate tumorigenesis, highlighting the importance of centrosome regulation in cancers (By similarity). ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Homodimer. Ubiquitinated by the SCF(Slimb) ubiquitin ligase complex; leading to its degradation by the proteasome during interphase and regulating centriole number and ensuring the block to centriole reduplication. Belongs to the protein kinase superfamily. Ser/Thr protein kinase family. CDC5/Polo subfamily.