Serine/threonine-protein kinase component of the chromosomal passenger complex (CPC), a complex that acts as a key regulator of mitosis (PubMed:11516652, PubMed:12925766, PubMed:14610074, PubMed:14722118). The CPC complex has essential functions at the centromere in ensuring correct chromosome alignment and segregation and is required for chromatin-induced microtubule stabilization and spindle assembly (PubMed:11516652, PubMed:12925766, PubMed:14610074, PubMed:14722118, PubMed:26829474). Involved in the bipolar attachment of spindle microtubules to kinetochores and is a key regulator for the onset of cytokinesis during mitosis (PubMed:15249581). Required for central/midzone spindle assembly and cleavage furrow formation (PubMed:12458200, PubMed:12686604). Key component of the cytokinesis checkpoint, a process required to delay abscission to prevent both premature resolution of intercellular chromosome bridges and accumulation of DNA damage: phosphorylates CHMP4C, leading to retain abscission-competent VPS4 (VPS4A and/or VPS4B) at the midbody ring until abscission checkpoint signaling is terminated at late cytokinesis (PubMed:22422861, PubMed:24814515). AURKB phosphorylates the CPC complex subunits BIRC5/survivin, CDCA8/borealin and INCENP (PubMed:11516652, PubMed:12925766, PubMed:14610074). Phosphorylation of INCENP leads to increased AURKB activity (PubMed:11516652, PubMed:12925766, PubMed:14610074). Other known AURKB substrates involved in centromeric functions and mitosis are CENPA, DES/desmin, GPAF, KIF2C, NSUN2, RACGAP1, SEPTIN1, VIM/vimentin, HASPIN, and histone H3 (PubMed:11784863, PubMed:12689593, PubMed:14602875, PubMed:11856369, PubMed:16103226, PubMed:21658950, PubMed:11756469). A positive feedback loop involving HASPIN and AURKB contributes to localization of CPC to centromeres (PubMed:21658950). Phosphorylation of VIM controls vimentin filament segregation in cytokinetic process, whereas histone H3 is phosphorylated at 'Ser-10' and 'Ser-28' during mitosis (H3S10ph and H3S28ph, respectively) (PubMed:11784863, PubMed:11856369). A positive feedback between HASPIN and AURKB contributes to CPC localization (PubMed:21658950). AURKB is also required for kinetochore localization of BUB1 and SGO1 (PubMed:15020684, PubMed:17617734). Phosphorylation of p53/TP53 negatively regulates its transcriptional activity (PubMed:20959462). Key regulator of active promoters in resting B- and T-lymphocytes: acts by mediating phosphorylation of H3S28ph at active promoters in resting B-cells, inhibiting RNF2/RING1B-mediated ubiquitination of histone H2A and enhancing binding and activity of the USP16 deubiquitinase at transcribed genes (By similarity). Acts as an inhibitor of CGAS during mitosis: catalyzes phosphorylation of the N-terminus of CGAS during the G2-M transition, blocking CGAS liquid phase separation and activation, and thereby preventing CGAS-induced autoimmunity (PubMed:33542149). Phosphorylates KRT5 during anaphase and telophase (By similarity). ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Activity is greatly increased when AURKB is within the CPC complex (PubMed:12925766, PubMed:14722118, PubMed:15249581). In particular, AURKB-phosphorylated INCENP acts as an activator of AURKB (PubMed:14722118, PubMed:15249581). Positive feedback between HASPIN and AURKB contributes to CPC localization (PubMed:14722118, PubMed:15249581). Component of the chromosomal passenger complex (CPC) composed of at least BIRC5/survivin, CDCA8/borealin, INCENP, AURKB or AURKC; predominantly independent AURKB- and AURKC-containing complexes exist (PubMed:11516652, PubMed:12925766, PubMed:14722118, PubMed:15249581, PubMed:18591255, PubMed:27332895, PubMed:20562864). Associates with RACGAP1 during M phase (PubMed:12689593). Interacts with CDCA1, EVI5, JTB, NDC80, PSMA3, SEPTIN1, SIRT2 and TACC1 (PubMed:14602875, PubMed:14674694, PubMed:15064709, PubMed:16179162, PubMed:16764853, PubMed:17726514, PubMed:21225229). Interacts with SPDYC; this interaction may be required for proper localization of active, Thr-232-phosphorylated AURKB form during prometaphase and metaphase (PubMed:20605920). Interacts with p53/TP53 (PubMed:20959462). Interacts (via the middle kinase domain) with NOC2L (via the N- and C-terminus domains) (PubMed:20959462). Interacts with TTC28 (PubMed:23036704). Interacts with RNF2/RING1B (By similarity). Localizes on chromosome arms and inner centromeres from prophase through metaphase and then transferring to the spindle midzone and midbody from anaphase through cytokinesis (PubMed:20929775). Colocalized with gamma tubulin in the midbody (PubMed:17726514). Proper localization of the active, Thr-232-phosphorylated form during metaphase may be dependent upon interaction with SPDYC (PubMed:20605920). Colocalized with SIRT2 during cytokinesis with the midbody (PubMed:17726514). Localization (and probably targeting of the CPC) to the inner centromere occurs predominantly in regions with overlapping mitosis-specific histone phosphorylations H3pT3 and H2ApT12 (PubMed:20929775). High level expression seen in the thymus. It is also expressed in the spleen, lung, testis, colon, placenta and fetal liver. Expressed during S and G2/M phase and expression is up-regulated in cancer cells during M phase. Not expressed in normal liver, high expression in metastatic liver. Expression is cell cycle-regulated, with a low in G1/S, an increase during G2 and M. Expression decreases again after M phase. The phosphorylation of Thr-232 requires the binding to INCENP and occurs by means of an autophosphorylation mechanism (PubMed:14722118). Thr-232 phosphorylation is indispensable for the AURKB kinase activity (PubMed:14722118, PubMed:26829474). Acetylated at Lys-215 by KAT5 at kinetochores, increasing AURKB activity and promoting accurate chromosome segregation in mitosis. Ubiquitinated by different BCR (BTB-CUL3-RBX1) E3 ubiquitin ligase complexes (PubMed:17543862, PubMed:19995937). Ubiquitinated by the BCR(KLHL9-KLHL13) E3 ubiquitin ligase complex, ubiquitination leads to removal from mitotic chromosomes and is required for cytokinesis (PubMed:17543862). During anaphase, the BCR(KLHL21) E3 ubiquitin ligase complex recruits the CPC complex from chromosomes to the spindle midzone and mediates the ubiquitination of AURKB (PubMed:17543862). Ubiquitination of AURKB by BCR(KLHL21) E3 ubiquitin ligase complex may not lead to its degradation by the proteasome (PubMed:19995937). Disruptive regulation of expression is a possible mechanism of the perturbation of chromosomal integrity in cancer cells through its dominant-negative effect on cytokinesis. Belongs to the protein kinase superfamily. Ser/Thr protein kinase family. Aurora subfamily. Extended N-terminus.