Mitotic checkpoint protein BUB3
Function
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.
Post-translational modifications
Poly-ADP-ribosylated by PARP1.
Ubiquitinated by UBR5, promoting disassembly of the mitotic checkpoint complex from the APC/C complex.
Sequence Similarities
Belongs to the WD repeat BUB3 family.
Cellular localization
- Nucleus
- Chromosome
- Centromere
- Kinetochore
- Starts to localize at kinetochores in prometaphase I (Pro-MI) stage and maintains the localization until the metaphase I-anaphase I (MI-AI) transition.
Alternative names
Mitotic checkpoint protein BUB3, BUB3