BUB1B
BUB1 Mitotic Checkpoint Serine/Threonine Kinase B
Gene Information Card
| Symbol | BUB1B |
|---|---|
| Full Name | BUB1 mitotic checkpoint serine/threonine kinase B |
| Gene Type | protein-coding |
| Chromosomal Location | 15q15.1 |
| NCBI Gene ID | 701 ncbi.nlm.nih.gov/gene/701 |
| Ensembl ID | ENSG00000156970 |
| UniProt ID | O60566 |
| OMIM ID | 602860 |
| HGNC ID | 1141 |
| Aliases | BUBR1, BUB1beta, MAD3L, SSK1 |
Description
BUB1B encodes BUBR1, a serine/threonine kinase essential for the spindle assembly checkpoint (SAC). It ensures proper chromosome segregation by inhibiting the anaphase-promoting complex/cyclosome (APC/C) until all kinetochores are attached to spindle microtubules. BUBR1 also has roles in kinetochore assembly and chromosome congression. Mutations cause mosaic variegated aneuploidy (MVA) syndrome and are associated with various cancers.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Mosaic variegated aneuploidy (MVA) syndrome | Biallelic loss-of-function mutations impair SAC, leading to premature chromatid separation and aneuploidy | OMIM #257300 |
| Colorectal cancer | Somatic mutations and reduced expression contribute to chromosomal instability | COSMIC, ClinVar |
| Breast cancer | Overexpression or underexpression linked to poor prognosis and aneuploidy | COSMIC, PubMed |
| Gastric cancer | BUB1B downregulation associated with microsatellite instability | COSMIC, PubMed |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 14.2 | Medium |
| Bone marrow | 12.8 | Medium |
| Lymph node | 11.5 | Medium |
| Spleen | 10.1 | Medium |
| Brain | 2.3 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HeLa | 18.5 | Cervical cancer line |
| K562 | 15.2 | Leukemia line |
| MCF7 | 12.0 | Breast cancer line |
| HCT116 | 14.8 | Colorectal cancer line |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.2440C>T (p.Arg814Ter) | Nonsense | Rare | Loss of function; associated with MVA syndrome |
| c.2150A>G (p.Asn717Ser) | Missense | Rare | Impaired kinase activity; MVA syndrome |
| c.1830delT (p.Phe610LeufsTer5) | Frameshift | Rare | Loss of function; MVA syndrome |
| c.2386G>A (p.Glu796Lys) | Missense | Somatic (0.2% in COSMIC) | Unknown functional effect; found in colorectal cancer |
Mutation functional classification
Loss of Function (LOF)
Biallelic truncating or missense mutations in the kinase domain or C-terminal region impair SAC function, causing aneuploidy and MVA syndrome.
Gain of Function (GOF)
Not well documented; overexpression in some cancers may promote mitotic slippage and aneuploidy.
Dominant Negative (DN)
Heterozygous missense mutations (e.g., p.Asn717Ser) can interfere with wild-type BUBR1 function, contributing to chromosomal instability.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Spindle Assembly Checkpoint (SAC) (Reactome: R-HSA-69618)
• Cell Cycle
• Mitotic (Reactome: R-HSA-69278)
• Resolution of Sister Chromatid Cohesion (Reactome: R-HSA-2500257)
Protein Summary
BUBR1 (UniProt O60566) is a 1050-amino acid multidomain protein with an N-terminal kinase domain, a central TPR (tetratricopeptide repeat) region, and a C-terminal domain that binds CDC20. It localizes to kinetochores during mitosis and is phosphorylated by multiple kinases including PLK1 and CDK1. BUBR1 inhibits APC/C-CDC20 by forming the mitotic checkpoint complex (MCC) with MAD2, BUB3, and CDC20. Loss of BUBR1 function leads to premature anaphase onset and aneuploidy.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| BUB1B-PAK6 Knockout HEK293 Cell Line | EDJ-KQ1241 | Human | 106821730 | Details Get a Quote |
| BUB1B-PAK6 Knockout A-549 Cell Line | EDJ-KQ20596 | Human | 106821730 | Details Get a Quote |
| BUB1B-PAK6 Knockout HCT 116 Cell Line | EDJ-KQ20597 | Human | 106821730 | Details Get a Quote |
| BUB1B-PAK6 Knockout HeLa Cell Line | EDJ-KQ20598 | Human | 106821730 | Details Get a Quote |
| BUB1B (p.K94=) Point Mutation in HAP1 Cell Line | EDC03425 | Human | 701 | Details Get a Quote |
| BUB1B (p.A388=) Point Mutation in HAP1 Cell Line | EDC03426 | Human | 701 | Details Get a Quote |
| BUB1B (c.179+34A>C )Point Mutation in HAP1 Cell Line | EDC03424 | Human | 701 | Details Get a Quote |
| BUB1B (c.1401+24A>G )Point Mutation in HAP1 Cell Line | EDC03427 | Human | 701 | Details Get a Quote |
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