Essential component of the mitotic checkpoint. Required for normal mitosis progression. The mitotic checkpoint delays anaphase until all chromosomes are properly attached to the mitotic spindle. One of its checkpoint functions is to inhibit the activity of the anaphase-promoting complex/cyclosome (APC/C) by blocking the binding of CDC20 to APC/C, independently of its kinase activity. The other is to monitor kinetochore activities that depend on the kinetochore motor CENPE. Required for kinetochore localization of CENPE. Negatively regulates PLK1 activity in interphase cells and suppresses centrosome amplification. Also implicated in triggering apoptosis in polyploid cells that exit aberrantly from mitotic arrest. May play a role for tumor suppression. Interacts with CENPE, CENPF, mitosin, PLK1 and BUB3. Part of a complex containing BUB3, CDC20 and BUB1B. Interacts with anaphase-promoting complex/cyclosome (APC/C). Interacts with CASC5. Induced during mitosis. Highly expressed in thymus followed by spleen. Preferentially expressed in tissues with a high mitotic index. Kinase activity stimulated by CENPE. Belongs to the protein kinase superfamily. Ser/Thr protein kinase family. BUB1 subfamily. 3 isoforms of the human protein are produced by alternative splicing. Note: This description may include information from UniProtKB.
Protein type: Protein kinase, Other; Protein kinase, Ser/Thr (non-receptor); Kinase, protein; EC 184.108.40.206; Other group; BUB family
Chromosomal Location of Human Ortholog: 15q15
Cellular Component: kinetochore; anaphase-promoting complex; perinuclear region of cytoplasm; cytoplasm; microtubule organizing center; outer kinetochore of condensed chromosome; spindle midzone; cytosol
Molecular Function: protein serine/threonine kinase activity; protein binding; ATP binding; protein kinase activity
Biological Process: cell proliferation; mitosis; negative regulation of ubiquitin-protein ligase activity during mitotic cell cycle; phosphoinositide-mediated signaling; regulation of ubiquitin-protein ligase activity during mitotic cell cycle; apoptosis; anaphase-promoting complex-dependent proteasomal ubiquitin-dependent protein catabolic process; mitotic cell cycle checkpoint; mitotic cell cycle spindle assembly checkpoint; mitotic cell cycle; cell cycle; protein amino acid phosphorylation; spindle organization and biogenesis; mitotic metaphase/anaphase transition
SS: The number of records in which this modification site was determined using site-specific methods. SS methods include amino acid sequencing, site-directed mutagenesis, modification site-specific antibodies, specific MS strategies, etc.