Bub1b Recombinant Rabbit mAb (S-3436-5)

Bub1b, also known as BubR1, is a critical serine/threonine kinase and an essential component of the spindle assembly checkpoint (SAC) that ensures high-fidelity chromosome segregation during mitosis by preventing premature anaphase onset until all kinetochores are properly attached to spindle microtubules. Functioning as part of the mitotic checkpoint complex (MCC) alongside Mad2, Cdc20, and Bub3, Bub1b inhibits the anaphase-promoting complex/cyclosome (APC/C) to halt cell cycle progression, thereby safeguarding genomic stability; beyond its canonical checkpoint role, it also facilitates the establishment of stable kinetochore-microtubule attachments and regulates sister chromatid cohesion through interactions with securin and cohesin complexes. Dysregulation or mutation of Bub1b leads to severe chromosomal instability (CIN), aneuploidy, and is strongly associated with developmental disorders such as mosaic variegated aneuploidy syndrome as well as tumorigenesis, while its age-dependent decline in expression has been implicated in the increased incidence of aneuploidy observed in aging tissues and oocytes.