Bubr1/BUB1B (BUB1B) Antibody – Mouse Monoclonal

This gene encodes a kinase involved in spindle checkpoint function. The protein has been localized to the kinetochore and plays a role in the inhibition of the anaphase-promoting complex/cyclosome (APC/C), delaying the onset of anaphase and ensuring proper chromosome segregation. Impaired spindle checkpoint function has been found in many forms of cancer. [provided by RefSeq, Jul 2008]

BUB1B: 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.

Protein type: Tumor suppressor; EC 2.7.11.1; Protein kinase, Other; Protein kinase, Ser/Thr (non-receptor); Kinase, protein; 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; regulation of ubiquitin-protein ligase activity during mitotic cell cycle; cell division; apoptosis; anaphase-promoting complex-dependent proteasomal ubiquitin-dependent protein catabolic process; mitotic cell cycle checkpoint; mitotic cell cycle spindle assembly checkpoint; mitotic cell cycle; protein amino acid phosphorylation; mitotic metaphase/anaphase transition

Disease: Mosaic Variegated Aneuploidy Syndrome 1; Premature Chromatid Separation Trait