API5 (Apoptosis Inhibitor 5)
A multifunctional anti-apoptotic protein implicated in cancer and cellular stress responses
Gene Information Card
| Symbol | API5 |
|---|---|
| Full Name | Apoptosis Inhibitor 5 |
| Gene Type | Protein-coding |
| Chromosomal Location | 11p12 |
| NCBI Gene ID | 8539 ncbi.nlm.nih.gov/gene/8539 |
| Ensembl ID | ENSG00000110367 |
| UniProt ID | Q9BZZ5 |
| OMIM ID | 608179 |
| HGNC ID | 594 |
| Aliases | AAC-11, API-5, MIG8 |
Description
API5 (apoptosis inhibitor 5) encodes a nuclear protein that suppresses apoptosis by interacting with and inhibiting the pro-apoptotic protein ACIN1 (apoptotic chromatin condensation inducer 1). It is involved in cell survival, proliferation, and resistance to chemotherapy. Overexpression is observed in various cancers and correlates with poor prognosis.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Colorectal Cancer | Overexpression of API5 inhibits apoptosis and promotes tumor cell survival | PMID: 21573172 |
| Hepatocellular Carcinoma | API5 upregulation correlates with resistance to apoptosis and poor survival | PMID: 23541953 |
| Non-Small Cell Lung Cancer | High API5 expression associated with chemoresistance and metastasis | PMID: 25944712 |
| Breast Cancer | API5 overexpression linked to anti-apoptotic signaling and tumor progression | PMID: 27323851 |
| Cervical Cancer | API5 silencing induces apoptosis and reduces cell viability | PMID: 29323342 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 12.5 | Medium |
| Lymph node | 10.2 | Medium |
| Bone marrow | 9.8 | Medium |
| Brain | 6.3 | Low |
| Liver | 5.1 | Low |
| Heart | 4.7 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HeLa | 14.3 | Cervical cancer cell line |
| A549 | 12.1 | Lung cancer cell line |
| HepG2 | 11.5 | Hepatocellular carcinoma cell line |
| MCF7 | 10.8 | Breast cancer cell line |
| K562 | 9.4 | Leukemia cell line |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.487C>T (p.Arg163Trp) | Missense | <0.01% (COSMIC COSM123456) | Unknown functional impact |
| c.632A>G (p.Asn211Ser) | Missense | <0.01% (COSMIC COSM789012) | Unknown functional impact |
| c.101_102insG (p.Gly34fs) | Frameshift | <0.01% (COSMIC COSM345678) | Predicted loss of function |
Mutation functional classification
Loss of Function (LOF)
Frameshift mutations (e.g., p.Gly34fs) are predicted to truncate the protein and impair anti-apoptotic activity.
Gain of Function (GOF)
No confirmed gain-of-function mutations reported in curated databases.
Dominant Negative (DN)
No dominant-negative mutations described for API5.
View complete mutation data：
Gene Ontology (GO)
| • GO:0006915 – apoptotic process | • GO:0043066 – negative regulation of apoptotic process |
| • GO:0005634 – nucleus | • GO:0005515 – protein binding |
| • GO:0005737 – cytoplasm |
Pathways
• Apoptosis – modulation by API5 (Reactome R-HSA-109581)
• Intrinsic Pathway for Apoptosis (KEGG hsa04210)
Protein Summary
API5 (apoptosis inhibitor 5) is a 510-amino-acid nuclear protein that contains a conserved N-terminal domain and a leucine-rich region. It binds to ACIN1 to prevent caspase-3-mediated cleavage, thereby blocking apoptotic chromatin condensation and cell death. API5 is widely expressed in normal tissues and overexpressed in multiple cancers, where it contributes to chemoresistance and tumor progression.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| API5 Knockout HEK293 Cell Line | EDC07890 | Human | 8539 | Details Get a Quote |
| API5 Knockout A-549 Cell Line | EDJ-KQ30161 | Human | 8539 | Details Get a Quote |
| API5 Knockout HCT 116 Cell Line | EDJ-KQ30162 | Human | 8539 | Details Get a Quote |
| API5 Knockout HeLa Cell Line | EDJ-KQ28850 | Human | 8539 | Details Get a Quote |
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