DEFB106A

Summary

DEFB106A (defensin beta 106A, HGNC:18088) is a protein-coding gene on chromosome 8p23.1, encoding Beta-defensin 106 (Q8N104). Has antibacterial activity.

Defensins form a family of antimicrobial and cytotoxic peptides made by neutrophils. Defensins are short, processed peptide molecules that are classified by structure into three groups: alpha-defensins, beta-defensins and theta-defensins. All beta-defensin genes are densely clustered in four to five syntenic chromosomal regions. Chromosome 8p23 contains at least two copies of the duplicated beta-defensin cluster. This duplication results in two identical copies of defensin, beta 106, DEFB106A and DEFB106B, in head-to-head orientation. This gene, DEFB106A, represents the more centromeric copy.

Source: NCBI Gene 245909 — RefSeq curated summary.

At a glance

• Clinical variants (ClinVar): 12 total
• MANE Select transcript: NM_152251

Identifiers

Gene identifiers

Field	Value
HGNC ID	HGNC:18088
Approved symbol	DEFB106A
Name	defensin beta 106A
Location	8p23.1
Locus type	gene with protein product
Status	Approved
Aliases	DEFB-6
Ensembl gene	ENSG00000186579
Ensembl biotype	protein_coding
Entrez	245909

Gene structure

Transcript identifiers

Ensembl transcripts: 1 — 1 protein_coding

ENST00000335186

RefSeq mRNA: 2 — MANE Select: NM_152251 NM_001422094, NM_152251

CCDS: CCDS34833

Canonical transcript exons

ENST00000335186 — 2 exons

Exon	Start	End
ENSE00001702507	7828805	7829053
ENSE00001730344	7825139	7825225

Expression profiles

Bgee: expression breadth broad, 27 present calls, max score 37.20.

FANTOM5 (CAGE): breadth tissue_specific, TPM avg 0.0076 / max 13.3959, expressed in 1 samples.

FANTOM5 promoters (1 alternative TSS)

Promoter ID	TPM avg	Samples expressed
205054	0.0076	1

Top tissues by expression

118 total, by Bgee expression score (0-100, higher = more expressed):

Tissue	Anatomy ID	Expression score	Quality
colonic epithelium	UBERON:0000397	37.20	gold quality
ventricular zone	UBERON:0003053	36.48	gold quality
cortical plate	UBERON:0005343	36.47	gold quality
bone marrow cell	CL:0002092	36.16	gold quality
ganglionic eminence	UBERON:0004023	35.49	gold quality
skeletal muscle tissue	UBERON:0001134	33.38	gold quality
hindlimb stylopod muscle	UBERON:0004252	32.15	gold quality
bone marrow	UBERON:0002371	31.74	gold quality
muscle tissue	UBERON:0002385	31.06	gold quality
sural nerve	UBERON:0015488	30.93	gold quality
stromal cell of endometrium	CL:0002255	29.87	gold quality
liver	UBERON:0002107	29.28	silver quality
prefrontal cortex	UBERON:0000451	29.04	gold quality
duodenum	UBERON:0002114	28.14	gold quality
lymph node	UBERON:0000029	27.57	gold quality
leukocyte	CL:0000738	27.36	gold quality
monocyte	CL:0000576	27.34	gold quality
tonsil	UBERON:0002372	27.05	gold quality
islet of Langerhans	UBERON:0000006	26.55	gold quality
vermiform appendix	UBERON:0001154	26.42	gold quality
blood	UBERON:0000178	26.41	gold quality
gall bladder	UBERON:0002110	25.98	gold quality
olfactory segment of nasal mucosa	UBERON:0005386	25.89	gold quality
placenta	UBERON:0001987	25.81	gold quality
urinary bladder	UBERON:0001255	25.72	gold quality
right lobe of liver	UBERON:0001114	25.56	gold quality
muscle of leg	UBERON:0001383	25.13	silver quality
fundus of stomach	UBERON:0001160	25.08	gold quality
primary visual cortex	UBERON:0002436	24.61	gold quality
ectocervix	UBERON:0012249	24.52	gold quality

Single-cell (SCXA)

Detected in 2 experiment(s), a significant marker in 1.

Experiment	Marker?	Max mean expression
E-HCAD-38	yes	1009.67
E-ANND-3	no	0.08

Regulation

Is transcription factor: no

miRNA regulators (miRDB)

6 targeting DEFB106A, top 30 by miRDB confidence (max_score; target_count = how many genes the miRNA targets in total — lower means more specific):

miRNA	Max score	Avg score	miRNA target_count
HSA-MIR-4729	99.69	72.18	4233
HSA-MIR-3191-5P	99.24	66.52	1722
HSA-MIR-154-5P	98.92	66.65	733
HSA-MIR-2467-3P	98.65	67.18	1969
HSA-MIR-518C-5P	98.53	69.20	1640
HSA-MIR-346	97.01	66.97	662

Literature-anchored findings (GeneRIF, showing 4)

• The epididymis-specific expression pattern of the beta-defensin isoform BD-6 has been characterized. (PMID:12193721)
• A pilot study with cRNA probes for in situ hybridization and a synthetic propeptide for the functional characterization demonstrated the tissue-/cell-specific expression and the strong antimicrobial activity of DEFB106 (PMID:12600824)
• DEFB106 (also known as DEFB6) displays antimicrobial activity against E. coli, C. albicans and S. aureus. (PMID:24189797)
• Unique properties of human beta-defensin 6 (hBD6) and glycosaminoglycan complex: sandwich-like dimerization and competition with the chemokine receptor 2 (CCR2) binding site. (PMID:24970887)

Cross-species orthologs

0 orthologs

Paralogs (1): DEFB106B (ENSG00000187082)

Protein

Protein identifiers

Beta-defensin 106 — Q8N104 (reviewed: Q8N104)

Alternative names: Beta-defensin 6, Defensin, beta 106

All UniProt accessions (1): Q8N104

UniProt curated annotations — full annotation on UniProt →

Function. Has antibacterial activity. Acts as a ligand for C-C chemokine receptor CCR2.

Subunit / interactions. Monomer. Interacts with CCR2 (via extracellular N-terminal region); this interaction may preferentially require specific tyrosine sulfation on CCR2.

Subcellular location. Secreted. Membrane.

Tissue specificity. Expressed specifically in epididymis and lung.

Similarity. Belongs to the beta-defensin family.

RefSeq proteins (2): NP_001409023, NP_689464* (*=MANE)

Domains & families (InterPro)

ID	Name	Type
IPR025933	Beta_defensin_dom	Domain

Pfam: PF13841

UniProt features (11 total): strand 4, disulfide bond 3, signal peptide 1, peptide 1, sequence conflict 1, helix 1

Structure

Experimental structures (PDB)

1 structures.

PDB	Method	Resolution (Å)
2LWL	SOLUTION NMR

Predicted structure (AlphaFold)

Model	pLDDT	Fraction very-high
AF-Q8N104-F1	82.12	0.46

Functional residue map

Curated UniProt residues grouped by drug-discovery relevance — catalytic, ligand-binding, modification, and mutation-validated positions. Source: UniProtKB sequence features.

Disulfide bonds (3): 26–53, 33–47, 37–54

Function

Pathways and Gene Ontology

Reactome pathways

2 pathways

ID	Pathway
R-HSA-1461957	Beta defensins
R-HSA-1461973	Defensins

MSigDB gene sets: 30 (showing top): REACTOME_INNATE_IMMUNE_SYSTEM, GOBP_DEFENSE_RESPONSE_TO_OTHER_ORGANISM, GOBP_DEFENSE_RESPONSE_TO_GRAM_NEGATIVE_BACTERIUM, GOMF_GLYCOSAMINOGLYCAN_BINDING, GOBP_DEFENSE_RESPONSE_TO_GRAM_POSITIVE_BACTERIUM, GOMF_G_PROTEIN_COUPLED_RECEPTOR_BINDING, GOBP_RESPONSE_TO_FUNGUS, GOBP_DEFENSE_RESPONSE_TO_BACTERIUM, GOMF_SIGNALING_RECEPTOR_BINDING, GOMF_HEPARIN_BINDING, ACEVEDO_METHYLATED_IN_LIVER_CANCER_DN, NAKAMURA_TUMOR_ZONE_PERIPHERAL_VS_CENTRAL_UP, GOMF_SULFUR_COMPOUND_BINDING, RAY_TUMORIGENESIS_BY_ERBB2_CDC25A_UP, GOMF_LIPOPOLYSACCHARIDE_BINDING

GO Biological Process (6): innate immune response (GO:0045087), defense response to Gram-negative bacterium (GO:0050829), defense response to Gram-positive bacterium (GO:0050830), antifungal innate immune response (GO:0061760), defense response (GO:0006952), defense response to bacterium (GO:0042742)

GO Molecular Function (4): lipopolysaccharide binding (GO:0001530), heparin binding (GO:0008201), CCR2 chemokine receptor binding (GO:0031727), protein binding (GO:0005515)

GO Cellular Component (4): nucleus (GO:0005634), membrane (GO:0016020), microvesicle (GO:1990742), extracellular region (GO:0005576)

Reactome top-level categories

Rollup of top-2 pathways:

Category	Pathways
Defensins	1
Antimicrobial peptides	1

GO top-level categories

Rollup of top GO terms by namespace:

Category	Terms
defense response to bacterium	2
cellular anatomical structure	2
immune response	1
defense response to symbiont	1
innate immune response	1
defense response to fungus	1
response to stress	1
defense response	1
response to bacterium	1
lipid binding	1
carbohydrate derivative binding	1
glycosaminoglycan binding	1
sulfur compound binding	1
CCR chemokine receptor binding	1
binding	1
intracellular membrane-bounded organelle	1
extracellular vesicle	1

Protein interactions and networks

STRING

192 interactions, top by confidence (×1000):

Protein A	Protein B	Partner UniProt	Score
DEFB106A	DEFB105A	Q8NG35	928
DEFB106A	DEFB104A	Q8WTQ1	893
DEFB106A	DEFB107A	Q8IZN7	865
DEFB106A	DEFB103A	P81534	861
DEFB106A	DEFB108B	Q8NET1	849
DEFB106A	A0A0G2JN59	A0A0G2JN59	836
DEFB106A	DEFB1	P60022	809
DEFB106A	CCR2	P41597	696
DEFB106A	DEFB4A	O15263	661
DEFB106A	DEFB126	Q9BYW3	603
DEFB106A	PRR23D1	E9PI22	594
DEFB106A	FAM90A7	A6NKC0	540
DEFB106A	DEFA5	Q01523	527
DEFB106A	USP17L4	A6NCW7	524
DEFB106A	DEFB113	Q30KQ7	507

IntAct

2 interactions, top by confidence:

A	B	Type	Score
DEFB106A	EMC8	psi-mi:“MI:0914”(association)	0.350

BioGRID (16): CTSV (Affinity Capture-MS), PCYOX1L (Affinity Capture-MS), TMEM2 (Affinity Capture-MS), IL37 (Affinity Capture-MS), CST6 (Affinity Capture-MS), EMC8 (Affinity Capture-MS), POF1B (Affinity Capture-MS), RNASE7 (Affinity Capture-MS), EMC4 (Affinity Capture-MS), EMC7 (Affinity Capture-MS), TGM1 (Affinity Capture-MS), CDSN (Affinity Capture-MS), CES3 (Affinity Capture-MS), SERPINB7 (Affinity Capture-MS), ALOX12B (Affinity Capture-MS)

ESM2 similar proteins: A4H202, A4H203, A4H204, A4H206, A4H209, A4H211, A4H212, A4H213, A4H225, A4H227, A8MXU0, O19039, O89117, P0C8A5, P0C8A6, P0C8A7, Q30KJ3, Q30KK4, Q30KK6, Q30KL6, Q30KN8, Q30KP6, Q30KP8, Q32P86, Q32ZF3, Q32ZG3, Q32ZG7, Q32ZH5, Q32ZH6, Q32ZH9, Q32ZI2, Q4QY38, Q5IAB3, Q5IAB9, Q5J5C9, Q5J5Z9, Q5J600, Q5J602, Q6GXJ1, Q6IV23

Diamond homologs: A4H211, A4H212, A4H213, Q32ZH6, Q5IAB3, Q7TNV8, Q8N104, Q8R2I5, Q5J5Z9, Q30KN4, A4H206, A4H207, A4H208, Q30KJ5, Q4QY38, A4H235, A4H236, A4H253, A4H254, A4H255, Q30KJ4, Q30KK5, Q30KL1, Q30KN8, Q30KP9, Q30KQ4, Q32ZG3, Q32ZG7, Q5J5D0, Q7Z7B8, Q8K3U4, Q8N688, A8MXU0, Q5IAA6, Q8NET1

SIGNOR signaling

0 interactions.

Disease & clinical

Clinical variants and AI predictions

ClinVar

12 variants total. Per-class counts are floors (≥ shown; pagination cap):

Classification	Count (floor)
Pathogenic	0
Likely pathogenic	0
Uncertain significance	8
Likely benign	4
Benign	0

Top pathogenic / likely-pathogenic (0)

SpliceAI

205 predictions. Top by Δscore:

Variant	Effect	Δscore
8:7825327:G:GT	donor_gain	0.9500
8:7825357:A:AG	donor_gain	0.9500
8:7825358:T:G	donor_gain	0.9500
8:7825353:T:G	donor_gain	0.8600
8:7828389:T:TA	acceptor_gain	0.8300
8:7825973:G:A	acceptor_gain	0.8100
8:7825327:GAG:G	donor_gain	0.7900
8:7825966:T:TA	acceptor_gain	0.7800
8:7825248:G:T	donor_gain	0.7600
8:7825354:G:GG	donor_gain	0.7400
8:7825325:AAGAG:A	donor_loss	0.7300
8:7825326:AGAGG:A	donor_loss	0.7300
8:7825328:AGG:A	donor_loss	0.7300
8:7825329:G:C	donor_loss	0.7300
8:7825330:G:GA	donor_loss	0.7300
8:7825331:T:A	donor_loss	0.7300
8:7825972:T:TA	acceptor_gain	0.7200
8:7828803:A:AG	acceptor_gain	0.7200
8:7828804:G:GG	acceptor_gain	0.7200
8:7825264:G:GA	donor_gain	0.7100
8:7828137:TGAA:T	acceptor_gain	0.7000
8:7828138:GAAG:G	acceptor_gain	0.7000
8:7825221:CCCAG:C	donor_loss	0.6600
8:7825222:CCAG:C	donor_loss	0.6600
8:7825223:CAG:C	donor_loss	0.6600
8:7825224:AGGTA:A	donor_loss	0.6600
8:7825225:GG:G	donor_loss	0.6600
8:7825226:GTAAA:G	donor_loss	0.6600
8:7825227:T:A	donor_loss	0.6600
8:7825228:A:C	donor_loss	0.6400

AlphaMissense

436 scored. Top likely-pathogenic:

Variant	Protein change	am_pathogenicity
8:7828831:T:A	C26S	0.973
8:7828832:G:C	C26S	0.973
8:7828912:T:A	C53S	0.962
8:7828913:G:C	C53S	0.962
8:7828912:T:C	C53R	0.950
8:7828852:T:A	C33S	0.948
8:7828853:G:C	C33S	0.948
8:7828894:T:A	C47S	0.946
8:7828895:G:C	C47S	0.946
8:7828914:C:G	C53W	0.945
8:7828896:C:G	C47W	0.942
8:7828831:T:C	C26R	0.940
8:7828894:T:C	C47R	0.937
8:7828833:C:G	C26W	0.936
8:7828915:T:A	C54S	0.932
8:7828916:G:C	C54S	0.932
8:7828832:G:T	C26F	0.926
8:7828846:G:A	G31R	0.925
8:7828846:G:C	G31R	0.925
8:7828832:G:A	C26Y	0.924
8:7828895:G:A	C47Y	0.923
8:7828864:T:A	C37S	0.921
8:7828865:G:C	C37S	0.921
8:7828853:G:A	C33Y	0.913
8:7828854:C:G	C33W	0.913
8:7828852:T:C	C33R	0.910
8:7828915:T:C	C54R	0.903
8:7828913:G:T	C53F	0.899
8:7828917:T:G	C54W	0.899
8:7828916:G:A	C54Y	0.898

dbSNP variants (sampled 300 via entrez): RS1000266698 (8:7826463 A>C), RS1004712005 (8:7826999 A>G), RS1012177705 (8:7826859 G>A,C), RS1014630976 (8:7827960 C>T), RS1014703136 (8:7827000 G>C), RS1014734449 (8:7828289 G>A,C), RS1024826176 (8:7824724 C>G,T), RS1025277846 (8:7826874 T>C), RS1029127453 (8:7828314 T>C), RS1034372470 (8:7826556 T>C), RS1041904105 (8:7826183 G>A), RS1041935249 (8:7827650 A>G,T), RS1045729176 (8:7827965 A>T), RS1052425383 (8:7825993 A>T), RS1055858539 (8:7827694 C>A)

Disease associations

OMIM: gene `` | disease phenotypes:

GenCC curated gene-disease

Mondo (0):

Orphanet (0):

HPO phenotypes

0 total (0 of 0 shown, HPO-id order):

GWAS associations

0 associations (top):

Drugs & pharmacology

Drug and pharmacology data

Is drug target: no

PharmGKB: 1 entry (VIP=true, CPIC=false)

CTD chemical–gene interactions

4 total (human), top 4 by PubMed support.

Chemical	Actions (top 5)	PubMed papers
2-palmitoylglycerol	increases expression	1
Cadmium	decreases expression, increases abundance	1
Aflatoxin B1	increases methylation	1
Cadmium Chloride	decreases expression, increases abundance	1

Clinical trials (associated diseases)

0 trials via MONDO — disease-level, not drug-specific.