Mitotic serine/threonine kinases that contributes to the regulation of cell cycle progression. Associates with the centrosome and the spindle microtubules during mitosis and plays a critical role in various mitotic events including the establishment of mitotic spindle, centrosome duplication, centrosome separation as well as maturation, chromosomal alignment, spindle assembly checkpoint, and cytokinesis. Phosphorylates numerous target proteins. Important for microtubule formation and/or stabilization. ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Interacts with kif2c and kif11. Localizes to the spindle pole during mitosis especially from prophase through anaphase. Partially colocalized with gamma tubulin in the centrosome, from S to M phase. Highly expressed in ovary and testis. Expressed maternally in oocytes, unfertilized eggs and embryos up to the mid-blastula transition (MBT). Phosphorylated (PubMed:9454730). Autophosphorylated on a serine residue (PubMed:9454730). Belongs to the protein kinase superfamily. Ser/Thr protein kinase family. Aurora subfamily.