CCNB1: Cyclin B1
Key regulator of G2/M cell cycle transition and mitotic entry
Gene Information Card
| Symbol | CCNB1 |
|---|---|
| Full Name | Cyclin B1 |
| Gene Type | Protein coding |
| Chromosomal Location | 5q13.2 |
| NCBI Gene ID | 891 ncbi.nlm.nih.gov/gene/891 |
| Ensembl ID | ENSG00000134057 |
| UniProt ID | P14635 |
| OMIM ID | 123836 |
| HGNC ID | 1579 |
| Aliases | CCNB, CCNB1-IT1 |
Description
CCNB1 encodes cyclin B1, a regulatory subunit of the cyclin-dependent kinase CDK1 (CDC2). Cyclin B1 accumulates during G2 phase and is required for the G2/M transition of the cell cycle. It forms the M-phase promoting factor (MPF) complex with CDK1, which phosphorylates numerous substrates to drive mitotic entry, chromosome condensation, nuclear envelope breakdown, and spindle assembly. Degradation of cyclin B1 via the anaphase-promoting complex/cyclosome (APC/C) is essential for mitotic exit. Overexpression and aberrant regulation of CCNB1 are frequently observed in various cancers and correlate with poor prognosis.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Breast cancer | Overexpression of CCNB1 promotes uncontrolled cell proliferation and resistance to apoptosis | PMID: 25652252; COSMIC |
| Colorectal cancer | Elevated cyclin B1 levels disrupt G2/M checkpoint, leading to genomic instability | PMID: 28209927; COSMIC |
| Lung cancer | CCNB1 amplification and overexpression associated with aggressive tumor behavior and poor survival | PMID: 29348694; COSMIC |
| Ovarian cancer | Cyclin B1 overexpression correlates with advanced stage and chemoresistance | PMID: 27050029; COSMIC |
| Hepatocellular carcinoma | Upregulation of CCNB1 promotes cell cycle progression and tumor growth | PMID: 30462238; COSMIC |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 48.2 | High |
| Bone marrow | 32.1 | High |
| Lymph node | 28.5 | High |
| Spleen | 25.0 | High |
| Thymus | 22.3 | High |
| Colon | 18.7 | Medium |
| Lung | 15.4 | Medium |
| Breast | 12.1 | Medium |
| Liver | 8.5 | Low |
| Brain | 3.2 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HeLa | 45.6 | Cervical cancer cell line; high expression |
| MCF7 | 38.2 | Breast cancer cell line; elevated |
| A549 | 35.1 | Lung cancer cell line; moderate-high |
| HCT116 | 40.3 | Colorectal cancer cell line; high |
| K562 | 30.7 | Leukemia cell line; moderate-high |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1072C>T (p.Arg358Trp) | Missense | <0.1% | Unknown functional impact; rare in COSMIC |
| c.1130A>G (p.Gln377Arg) | Missense | <0.1% | Reported in breast cancer; uncertain significance |
| c.1243G>A (p.Gly415Arg) | Missense | <0.1% | Observed in lung cancer; likely benign |
| Amplification | Copy number gain | ~5-10% in various cancers | Leads to overexpression and oncogenic activity |
Mutation functional classification
Loss of Function (LOF)
No confirmed loss-of-function mutations reported; CCNB1 is essential for cell cycle progression and complete loss is likely lethal.
Gain of Function (GOF)
Amplification and overexpression act as gain-of-function events, driving unscheduled mitotic entry and proliferation.
Dominant Negative (DN)
Not described for CCNB1; dominant-negative effects are not established.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Cell Cycle (KEGG: hsa04110)
• p53 signaling pathway (KEGG: hsa04115)
• Oocyte meiosis (KEGG: hsa04114)
• Progesterone-mediated oocyte maturation (KEGG: hsa04914)
• FoxO signaling pathway (KEGG: hsa04068)
Protein Summary
Cyclin B1 is a 433-amino-acid protein (48 kDa) that contains a cyclin box domain responsible for CDK1 binding and activation. It shuttles between the cytoplasm and nucleus; during interphase it is predominantly cytoplasmic, and at the G2/M transition it translocates to the nucleus. The N-terminal region contains a destruction box (D-box) required for APC/C-mediated ubiquitination and proteasomal degradation. Phosphorylation at Ser126, Ser128, Ser133, and Ser147 regulates its subcellular localization and stability. Cyclin B1 is overexpressed in many cancers and is a target for anticancer therapies.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| CCNB1IP1 Knockout HEK293 Cell Line | EDJ-KQ12820 | Human | 57820 | Details Get a Quote |
| CCNB1IP1 Knockout HCT 116 Cell Line | EDJ-KQ41955 | Human | 57820 | Details Get a Quote |
| CCNB1IP1 Knockout HeLa Cell Line | EDJ-KQ41956 | Human | 57820 | Details Get a Quote |
| CCNB1IP1 Knockout A-549 Cell Line | EDJ-KQ40706 | Human | 57820 | Details Get a Quote |
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