Phosphorylates specifically 'Ser-10' of histone H3 in vitro. Associates with cytoskeletal structures that are necessary for cytokinesis and with the microtubule spindle. Might colocalize with gamma-tubulin and function in microtubule organizing centers (MTOCs). ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Nuclear membrane in interphase cells, spindle poles at prophase and mitotic spindle from metaphase to telophase. Abundant in roots, flowers and flower buds, low or absent in expanded leaves, stems and siliques. Expression peaks at mitosis. Phosphorylation at Thr-173 may regulate activity and degradation of AUR2 in a cell cycle dependent manner. Belongs to the protein kinase superfamily. Ser/Thr protein kinase family. Aurora subfamily.