BUB3
BUB3 (BUB3 mitotic checkpoint protein, also known as BUB3L) is a WD repeat protein with a dual role in spindle-assembly checkpoint signalling and in establishing correct kinetochore-microtubule attachments. It localises to the nucleus and to the kinetochore at the centromere. Browse Assay Genie's current range of BUB3 research reagents below, or read on for the biology behind the target.
BUB3 has a dual function in spindle-assembly checkpoint signalling and in promoting the establishment of correct kinetochore-microtubule (K-MT) attachments. It promotes the formation of stable end-on bipolar attachments and is necessary for the kinetochore localisation of BUB1. BUB3 also regulates chromosome segregation during oocyte meiosis.
Within the checkpoint, the BUB1/BUB3 complex helps inhibit the anaphase-promoting complex or cyclosome (APC/C) when the spindle-assembly checkpoint is activated. The complex inhibits the ubiquitin ligase activity of APC/C by phosphorylating its activator CDC20, and it can also phosphorylate MAD1L1. In this way BUB3 contributes to accurate chromosome segregation during cell division.
The human BUB3 gene encodes a protein that contains four WD repeat domains and has sequence similarity with the yeast BUB3 protein. It belongs to the WD repeat BUB3 family and is classified by HGNC in the WD repeat domain containing gene group. Alternate transcriptional splice variants encoding different isoforms have been characterised. The gene was previously named BUB3 (budding uninhibited by benzimidazoles 3, yeast) homolog, and the mouse ortholog is Bub3. Researchers studying the BUB3 gene or protein often do so in the context of mitotic fidelity and kinetochore biology.
BUB3 acts with BUB1 to inhibit APC/C when the spindle-assembly checkpoint is active, making it a core component for studying mitotic arrest.
BUB3 is needed for kinetochore localisation of BUB1 and promotes stable end-on bipolar kinetochore-microtubule attachments.
BUB3 helps regulate chromosome segregation, including during oocyte meiosis, so it is relevant to studies of segregation accuracy.
The BUB1/BUB3 complex phosphorylates CDC20 to inhibit APC/C ubiquitin ligase activity, a mechanism central to cell-cycle control research.
BUB3 functions in spindle-assembly checkpoint signalling and in establishing correct kinetochore-microtubule attachments. It is needed for BUB1 to localise to kinetochores, and the BUB1/BUB3 complex inhibits APC/C by phosphorylating CDC20. It also regulates chromosome segregation during oocyte meiosis.
BUB3 is also known as BUB3L, and the full HGNC name is BUB3 mitotic checkpoint protein. Earlier names referred to budding uninhibited by benzimidazoles 3 homolog (yeast). NCBI Gene reports that alternate splice variants encode different isoforms.
BUB3 shows sequence similarity with the yeast BUB3 protein, and the human protein contains four WD repeat domains. The mouse ortholog is Bub3. Please check the datasheet of any product for its validated reactivity.
Other spindle-assembly checkpoint components and mitotic regulators that act alongside BUB3.
Gene and protein annotations from HGNC, NCBI Gene and UniProt O43684; product specifications from Assay Genie datasheets.