DEFB1: Defensin Beta 1
Antimicrobial peptide gene involved in innate immunity and epithelial defense
Gene Information Card
| Symbol | DEFB1 |
|---|---|
| Full Name | Defensin Beta 1 |
| Gene Type | protein-coding |
| Chromosomal Location | 8p23.1 |
| NCBI Gene ID | 1672 ncbi.nlm.nih.gov/gene/1672 |
| Ensembl ID | ENSG00000164821 |
| UniProt ID | P60022 |
| OMIM ID | 602056 |
| HGNC ID | 2766 |
| Aliases | BD1, HBD1, DEFB-1, DEFB101 |
Description
DEFB1 encodes beta-defensin 1, a cationic antimicrobial peptide constitutively expressed in epithelial tissues. It plays a key role in innate immune defense against bacteria, fungi, and viruses by disrupting microbial membranes. The gene is located in a cluster of defensin genes on chromosome 8p23.1 and exhibits copy number variation. DEFB1 expression is regulated by inflammatory signals and contributes to mucosal barrier function.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Cystic Fibrosis | Reduced DEFB1 expression in airway epithelium may impair defense against Pseudomonas aeruginosa | PMID: 14699417 |
| Chronic Obstructive Pulmonary Disease (COPD) | Altered DEFB1 levels associated with airway inflammation and bacterial colonization | PMID: 21532022 |
| Inflammatory Bowel Disease | DEFB1 polymorphisms linked to Crohn's disease susceptibility | PMID: 19177459 |
| HIV-1 Infection | DEFB1 polymorphisms influence susceptibility to HIV-1 infection | PMID: 15852023 |
| Candidiasis | DEFB1 deficiency associated with increased oral Candida colonization | PMID: 19656187 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Kidney | 12.5 | Medium |
| Lung | 8.3 | Medium |
| Trachea | 7.1 | Medium |
| Salivary Gland | 6.8 | Medium |
| Skin | 4.2 | Low |
| Colon | 3.9 | Low |
| Prostate | 3.5 | Low |
| Testis | 2.1 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| A549 (lung carcinoma) | 5.2 | Constitutive expression |
| Caco-2 (colorectal adenocarcinoma) | 4.8 | Moderate expression |
| HaCaT (keratinocyte) | 3.1 | Low expression |
| HepG2 (hepatocellular carcinoma) | 1.5 | Very low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| rs11362 (G-20A) | SNP (5' UTR) | 0.35 (global) | Alters transcription factor binding; associated with altered DEFB1 expression |
| rs1799946 (G-52A) | SNP (5' UTR) | 0.28 (global) | Linked to COPD and HIV susceptibility |
| rs1800972 (C-44G) | SNP (5' UTR) | 0.22 (global) | Associated with Crohn's disease risk |
Mutation functional classification
Loss of Function (LOF)
Rare nonsense or frameshift mutations leading to truncated protein; not well documented in large cohorts.
Gain of Function (GOF)
Not reported for DEFB1.
Dominant Negative (DN)
Not applicable; DEFB1 acts as a monomeric peptide.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Innate Immune System (Reactome: R-HSA-168249)
• Antimicrobial peptides (Reactome: R-HSA-6803157)
Protein Summary
Beta-defensin 1 is a 36-amino acid secreted peptide with three disulfide bonds forming a beta-sheet structure. It is constitutively expressed in epithelial cells and exhibits broad-spectrum antimicrobial activity. The protein is processed from a 68-amino acid prepropeptide. DEFB1 is also involved in chemotaxis and immune modulation.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| DEFB118 Knockout HEK293 Cell Line | EDJ-KQ7605 | Human | 117285 | Details Get a Quote |
| DEFB126 Knockout HEK293 Cell Line | EDJ-KQ9730 | Human | 81623 | Details Get a Quote |
| DEFB104A Knockout HEK293 Cell Line | EDJ-KQ9787 | Human | 140596 | Details Get a Quote |
| DEFB127 Knockout HEK293 Cell Line | EDJ-KQ9820 | Human | 140850 | Details Get a Quote |
| DEFB129 Knockout HEK293 Cell Line | EDJ-KQ9826 | Human | 140881 | Details Get a Quote |
| DEFB114 Knockout HEK293 Cell Line | EDJ-KQ10840 | Human | 245928 | Details Get a Quote |
| DEFB106A Knockout HEK293 Cell Line | EDJ-KQ11505 | Human | 245909 | Details Get a Quote |
| DEFB112 Knockout HEK293 Cell Line | EDJ-KQ11507 | Human | 245915 | Details Get a Quote |
| DEFB107A Knockout HEK293 Cell Line | EDJ-KQ11508 | Human | 245910 | Details Get a Quote |
| DEFB105A Knockout HEK293 Cell Line | EDJ-KQ11509 | Human | 245908 | Details Get a Quote |
| DEFB108B Knockout HEK293 Cell Line | EDJ-KQ11510 | Human | 245911 | Details Get a Quote |
| DEFB113 Knockout HEK293 Cell Line | EDJ-KQ11511 | Human | 245927 | Details Get a Quote |
| DEFB115 Knockout HEK293 Cell Line | EDJ-KQ11512 | Human | 245929 | Details Get a Quote |
| DEFB119 Knockout HEK293 Cell Line | EDJ-KQ11513 | Human | 245932 | Details Get a Quote |
| DEFB121 Knockout HEK293 Cell Line | EDJ-KQ11514 | Human | 245934 | Details Get a Quote |
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