BUB3 cDNA Clone – Budding Uninhibited by Benzimidazoles 3 Homolog (Yeast) (Human)

This gene encodes a protein involved in spindle checkpoint function. The encoded protein contains four WD repeat domains and has sequence similarity with the yeast BUB3 protein. Alternate transcriptional splice variants, encoding different isoforms, have been characterized. [provided by RefSeq, Jul 2008]

BUB3: Has a dual function in spindle-assembly checkpoint signaling and in promoting the establishment of correct kinetochore-microtubule (K-MT) attachments. Promotes the formation of stable end-on bipolar attachments. Necessary for kinetochore localization of BUB1. Regulates chromosome segregation during oocyte meiosis. The BUB1/BUB3 complex plays a role in the inhibition of anaphase-promoting complex or cyclosome (APC/C) when spindle-assembly checkpoint is activated and inhibits the ubiquitin ligase activity of APC/C by phosphorylating its activator CDC20. This complex can also phosphorylate MAD1L1. Interacts with BUB1 and BUBR1. The BUB1/BUB3 complex interacts with MAD1L1. Belongs to the WD repeat BUB3 family. 2 isoforms of the human protein are produced by alternative splicing.

Protein type: Cell cycle regulation

Chromosomal Location of Human Ortholog: 10q26

Cellular Component: cytosol; kinetochore; nucleoplasm

Molecular Function: protein binding; ubiquitin binding

Biological Process: anaphase-promoting complex-dependent proteasomal ubiquitin-dependent protein catabolic process; attachment of spindle microtubules to kinetochore; mitotic cell cycle spindle assembly checkpoint; negative regulation of ubiquitin-protein ligase activity during mitotic cell cycle; positive regulation of ubiquitin-protein ligase activity during mitotic cell cycle; proteasomal ubiquitin-dependent protein catabolic process; protein ubiquitination during ubiquitin-dependent protein catabolic process; sister chromatid cohesion