DEFA4 (Defensin Alpha 4) Gene
Neutrophil-specific alpha-defensin involved in antimicrobial host defense
Gene Information Card
| Symbol | DEFA4 |
|---|---|
| Full Name | Defensin Alpha 4 |
| Gene Type | Protein coding |
| Chromosomal Location | 8p23.1 |
| NCBI Gene ID | 1669 ncbi.nlm.nih.gov/gene/1669 |
| Ensembl ID | ENSG00000164821 |
| UniProt ID | P12838 |
| OMIM ID | 601157 |
| HGNC ID | 2763 |
| Aliases | HNP-4, DEF4, HP-4 |
Description
DEFA4 encodes defensin alpha 4, a member of the alpha-defensin family of antimicrobial peptides. These peptides are produced primarily by neutrophils and play a key role in innate immunity by disrupting the membranes of bacteria, fungi, and enveloped viruses. DEFA4 is specifically expressed in neutrophil precursor cells and stored in azurophil granules.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Cystic Fibrosis | Altered defensin expression may impair airway antimicrobial defense | PMID: 10651944 |
| Inflammatory Bowel Disease | Reduced alpha-defensin levels in Paneth cells linked to mucosal dysbiosis | PMID: 19029978 |
| Neutropenia | Deficiency of neutrophil defensins contributes to increased infection risk | PMID: 10587333 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Bone Marrow | 12.5 | High |
| Spleen | 2.1 | Low |
| Lung | 0.8 | Not detected |
| Small Intestine | 0.5 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HL-60 (promyelocytic leukemia) | 15.3 | High expression; induced upon differentiation |
| K-562 (chronic myeloid leukemia) | 0.2 | Very low expression |
| THP-1 (monocytic leukemia) | 0.1 | Not detected |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1A>G | Missense | <0.01% | Unknown functional impact |
| c.94C>T | Synonymous | <0.01% | No amino acid change |
Mutation functional classification
Loss of Function (LOF)
No confirmed loss-of-function mutations reported in DEFA4.
Gain of Function (GOF)
No confirmed gain-of-function mutations reported.
Dominant Negative (DN)
No dominant-negative mutations described.
View complete mutation data：
Gene Ontology (GO)
| • extracellular region (GO:0005576) | • extracellular space (GO:0005615) |
| • defense response to bacterium (GO:0042742) | • defense response to fungus (GO:0050832) |
| • defense response to virus (GO:0044179) | • killing of cells of another organism (GO:0031640) |
Pathways
• Innate Immune System (Reactome: R-HSA-168249)
• Antimicrobial peptides (Reactome: R-HSA-6803157)
Protein Summary
Defensin alpha 4 (HNP-4) is a 33-amino acid mature peptide with a characteristic beta-sheet structure stabilized by three disulfide bonds. It is synthesized as a preproprotein and processed to the active form in neutrophil granules. HNP-4 exhibits broad-spectrum antimicrobial activity and can modulate immune responses by chemotaxis and cytokine release.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| DEFA4 Knockout HEK293 Cell Line | EDJ-KQ4437 | Human | 1669 | Details Get a Quote |
| DEFA4 Knockout HeLa Cell Line | EDJ-KQ53083 | Human | 1669 | Details Get a Quote |
| DEFA4 Knockout A-549 Cell Line | EDJ-KQ61549 | Human | 1669 | Details Get a Quote |
| DEFA4 Knockout HCT 116 Cell Line | EDJ-KQ70041 | Human | 1669 | Details Get a Quote |
