Mitotic checkpoint serine/threonine-protein kinase BUB1 also known as BUB1 (budding uninhibited by benzimidazoles 1) is an enzyme that in humans is encoded by the BUB1 gene.

Bub1 is a serine/threonine protein kinase first identified in genetic screens of Saccharomyces cerevisiae.The protein is bound to kinetochores and plays a key role in the establishment of the mitotic spindle checkpoint and chromosome congression. The mitotic checkpoint kinase is evolutionary conserved in organisms as diverse as Saccharomyces cerevisiae and humans. Loss-of-function mutations or absence of Bub1 has been reported to result in aneuploidy, chromosomal instability (CIN) and premature senescence.

This gene encodes a kinase involved in spindle checkpoint function. The kinase functions in part by phosphorylating a member of the miotic checkpoint complex and activating the spindle checkpoint. Mutations in this gene have been associated with aneuploidy and several forms of cancer. [provided by RefSeq]. Publication Note: This RefSeq record includes a subset of the publications that are available for this gene. Please see the Gene record to access additional publications.