APOBEC3A_B
APOBEC3A and APOBEC3B Chimeric Gene
Gene Information Card
| Symbol | APOBEC3A_B |
|---|---|
| Full Name | APOBEC3A and APOBEC3B chimeric gene |
| Gene Type | chimeric gene (fusion) |
| Chromosomal Location | 22q13.1 |
| NCBI Gene ID | 100418043 ncbi.nlm.nih.gov/gene/100418043 |
| Ensembl ID | ENSG00000260007 |
| UniProt ID | P31941 (APOBEC3A); Q9UH17 (APOBEC3B) |
| OMIM ID | 607109 (APOBEC3A); 607110 (APOBEC3B) |
| HGNC ID | HGNC:24285 |
| Aliases | A3A_B, APOBEC3A/3B hybrid, APOBEC3A_B deletion allele |
Description
APOBEC3A_B is a chimeric gene formed by a 29.5 kb germline deletion that fuses the 5' end of APOBEC3A with the 3' end of APOBEC3B. This hybrid gene encodes a DNA cytidine deaminase with activity similar to APOBEC3A, contributing to APOBEC-signature mutagenesis in multiple cancer types. The deletion allele is common in East Asian populations and is associated with increased cancer risk.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Breast Cancer | APOBEC3A_B expression leads to APOBEC-signature mutations (C-to-T transitions) in genomic DNA, promoting tumorigenesis | PMID: 23242139, 25203321 |
| Bladder Cancer | Hybrid gene activity induces APOBEC mutagenesis, associated with poor prognosis | PMID: 25203321, 26632259 |
| Lung Cancer | APOBEC3A_B deaminase activity contributes to mutational signatures in lung adenocarcinoma | PMID: 26632259 |
| Ovarian Cancer | APOBEC3A_B expression linked to APOBEC mutation clusters in high-grade serous ovarian cancer | PMID: 25203321 |
| Cervical Cancer | APOBEC3A_B-mediated mutagenesis implicated in HPV-associated cervical carcinogenesis | PMID: 26632259 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Lymph node | 0.3 nTPM | Low |
| Spleen | 0.2 nTPM | Low |
| Bone marrow | 0.1 nTPM | Low |
| Other tissues | Not detected | Not expressed |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HeLa (cervical cancer) | 0.5 nTPM | Low expression |
| MCF7 (breast cancer) | 0.4 nTPM | Low expression |
| A549 (lung cancer) | 0.3 nTPM | Low expression |
| HEK293 (embryonic kidney) | 0.2 nTPM | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| Germline deletion (29.5 kb) | Structural variant | Common in East Asians (allele frequency ~37%) | Creates chimeric APOBEC3A_B gene with increased deaminase activity |
| Somatic APOBEC signature mutations | C-to-T transitions | High in APOBEC3A_B carriers | Drives tumor mutagenesis in breast, bladder, and lung cancers |
Mutation functional classification
Loss of Function (LOF)
Not applicable; the chimeric gene is a gain-of-function variant.
Gain of Function (GOF)
The APOBEC3A_B hybrid exhibits enhanced DNA deaminase activity compared to APOBEC3B, leading to increased APOBEC-signature mutagenesis in cancer.
Dominant Negative (DN)
Not reported.
View complete mutation data：
Gene Ontology (GO)
| • GO:0003824 (GO:0003824) | • GO:0008270 (GO:0008270) |
| • GO:0005634 (GO:0005634) | • GO:0005737 (GO:0005737) |
| • GO:0006304 (GO:0006304) | • GO:0006305 (GO:0006305) |
| • GO:0009986 (GO:0009986) | • GO:0016020 (GO:0016020) |
| • GO:0030141 (GO:0030141) | • GO:0042802 (GO:0042802) |
| • GO:0046872 (GO:0046872) | • GO:0051536 (GO:0051536) |
| • GO:0051539 (GO:0051539) | • GO:0070062 (GO:0070062) |
Pathways
• APOBEC-mediated mutagenesis pathway
• Cytidine deamination in cancer
• DNA damage response
Protein Summary
The APOBEC3A_B chimeric protein is a DNA cytidine deaminase that converts cytosine to uracil in single-stranded DNA. It is composed of the N-terminal domain from APOBEC3A and the C-terminal domain from APOBEC3B. This hybrid exhibits high catalytic activity similar to APOBEC3A, leading to APOBEC-signature mutations (C-to-T transitions) in cancer genomes. The protein is localized to the nucleus and cytoplasm and is implicated in innate immunity against retroviruses and retrotransposons, but its overexpression in cancer drives mutagenesis.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| APOBEC3A_B Knockout HEK293 Cell Line | EDJ-KQ11872 | Human | 100913187 | Details Get a Quote |
| APOBEC3A_B Knockout HCT 116 Cell Line | EDJ-KQ39064 | Human | 100913187 | Details Get a Quote |
| APOBEC3A_B Knockout A-549 Cell Line | EDJ-KQ40304 | Human | 100913187 | Details Get a Quote |
| APOBEC3A_B Knockout HeLa Cell Line | EDJ-KQ40305 | Human | 100913187 | Details Get a Quote |
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