BUB1
BUB1 (mitotic checkpoint serine/threonine-protein kinase BUB1, also known as hBUB1, BUB1A or BUB1L) is a kinase that acts during mitosis. It supports spindle-assembly checkpoint signalling and correct chromosome alignment at the kinetochore. Browse Assay Genie's current range of BUB1 research reagents below, or read on for the biology behind the target.
BUB1 is a serine/threonine-protein kinase with two crucial roles in mitosis: it is essential for spindle-assembly checkpoint signalling and for correct chromosome alignment. It has a key role in assembling checkpoint proteins at the kinetochore, and is required for the subsequent localisation of CENPF, BUB1B, CENPE and MAD2L1. It is also required for kinetochore localisation of PLK1 and for centromeric enrichment of AURKB in prometaphase. BUB1 helps define SGO1 localisation, and so affects sister chromatid cohesion, and promotes centromeric localisation of TOP2A.
BUB1 works in complex with BUB3. Binding to BUB3 is essential for proper chromosome segregation, and BUB1 can phosphorylate BUB3. When the spindle-assembly checkpoint is activated, the BUB1-BUB3 complex helps inhibit the anaphase-promoting complex/cyclosome (APC/C) by phosphorylating its activator CDC20. The complex can also phosphorylate MAD1L1. Kinase activity is essential for inhibition of APC/C-CDC20 and for chromosome alignment, but does not play a major role in checkpoint activity itself. BUB1 is also a substrate of APC/C in complex with CDH1, and can regulate chromosome segregation in a kinetochore-independent manner. It localises to the nucleus and to the kinetochore at the centromere.
The BUB1 gene belongs to the BUB1 subfamily of the Ser/Thr protein kinase family within the protein kinase superfamily. The gene name derives from the yeast screen for budding uninhibited by benzimidazoles. BUB1 mediates cell death in response to chromosome missegregation and acts to suppress spontaneous tumorigenesis. Mutations in the gene have been associated with aneuploidy and several forms of cancer, and it may also function in the DNA damage response. Alternate splicing gives multiple transcript variants.
BUB1 is essential for spindle-assembly checkpoint signalling and phosphorylates CDC20 and MAD1L1, making it a core component for studying checkpoint activation.
BUB1 kinase activity is needed for chromosome alignment, and its BUB3 binding is essential for proper chromosome segregation.
BUB1 is required for localisation of CENPF, BUB1B, CENPE, MAD2L1 and PLK1 at the kinetochore, so it is central to kinetochore studies.
BUB1 suppresses spontaneous tumorigenesis, and mutations are associated with aneuploidy and several forms of cancer.
BUB1 is a serine/threonine kinase that is essential for spindle-assembly checkpoint signalling and correct chromosome alignment in mitosis. It helps assemble checkpoint proteins at the kinetochore and, with BUB3, phosphorylates CDC20 to inhibit APC/C when the checkpoint is active.
BUB1 is also known as hBUB1, BUB1A and BUB1L. The HGNC name is BUB1 mitotic checkpoint serine/threonine kinase, and earlier names refer to the yeast homologue, budding uninhibited by benzimidazoles 1. Alternate splicing produces multiple transcript variants.
Mutations in the BUB1 gene have been associated with aneuploidy and several forms of cancer, and BUB1 acts to suppress spontaneous tumorigenesis. The mouse ortholog is Bub1; check the datasheet of any product for its validated reactivity.
Binding partners and checkpoint proteins that work alongside BUB1 in mitosis.
Gene and protein annotations from HGNC, NCBI Gene and UniProt O43683; product specifications from Assay Genie datasheets.