DEFB106B

Summary

DEFB106B (defensin beta 106B, HGNC:28879) 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, DEFB106B, represents the more telomeric copy.

Source: NCBI Gene 503841 — RefSeq curated summary.

At a glance

• Clinical variants (ClinVar): 9 total
• MANE Select transcript: NM_001040704

Identifiers

Gene identifiers

Field	Value
HGNC ID	HGNC:28879
Approved symbol	DEFB106B
Name	defensin beta 106B
Location	8p23.1
Locus type	gene with protein product
Status	Approved
Ensembl gene	ENSG00000187082
Ensembl biotype	protein_coding
Entrez	503841

Gene structure

Transcript identifiers

Ensembl transcripts: 1 — 1 protein_coding

ENST00000335479

RefSeq mRNA: 2 — MANE Select: NM_001040704 NM_001040704, NM_001422094

CCDS: CCDS34813

Canonical transcript exons

ENST00000335479 — 2 exons

Exon	Start	End
ENSE00001678637	7482504	7482752
ENSE00001782213	7486334	7486400

Expression profiles

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

Top tissues by expression

105 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
monocyte	CL:0000576	32.30	gold quality
hindlimb stylopod muscle	UBERON:0004252	32.15	gold quality
leukocyte	CL:0000738	31.88	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
prefrontal cortex	UBERON:0000451	29.04	gold quality
urinary bladder	UBERON:0001255	28.52	gold quality
duodenum	UBERON:0002114	28.14	gold quality
lymph node	UBERON:0000029	27.57	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
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
uterine cervix	UBERON:0000002	25.49	gold quality
right adrenal gland	UBERON:0001233	25.23	gold quality
primary visual cortex	UBERON:0002436	24.61	gold quality
right adrenal gland cortex	UBERON:0035827	24.56	silver quality
superior frontal gyrus	UBERON:0002661	24.08	gold quality
ectocervix	UBERON:0012249	23.97	gold quality
frontal cortex	UBERON:0001870	23.71	gold quality

Single-cell (SCXA)

Detected in 1 experiment(s), a significant marker in 0.

Experiment	Marker?	Max mean expression
E-ANND-3	no	0.00

Regulation

Is transcription factor: no

miRNA regulators (miRDB)

6 targeting DEFB106B, 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 1)

• DEFB106 (also known as DEFB6) displays antimicrobial activity against E. coli, C. albicans and S. aureus. (PMID:24189797)

Cross-species orthologs

0 orthologs

Paralogs (1): DEFB106A (ENSG00000186579)

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_001035794, NP_001409023 (=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: 29 (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, GOMF_SULFUR_COMPOUND_BINDING, GOMF_LIPOPOLYSACCHARIDE_BINDING, GOMF_CCR_CHEMOKINE_RECEPTOR_BINDING, GOBP_RESPONSE_TO_BACTERIUM, GOMF_LIPID_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
DEFB106B	DEFB105A	Q8NG35	928
DEFB106B	DEFB104A	Q8WTQ1	893
DEFB106B	DEFB107A	Q8IZN7	865
DEFB106B	DEFB103A	P81534	861
DEFB106B	DEFB108B	Q8NET1	849
DEFB106B	A0A0G2JN59	A0A0G2JN59	836
DEFB106B	DEFB1	P60022	809
DEFB106B	CCR2	P41597	696
DEFB106B	DEFB4A	O15263	661
DEFB106B	DEFB126	Q9BYW3	603
DEFB106B	PRR23D1	E9PI22	594
DEFB106B	FAM90A7	A6NKC0	540
DEFB106B	DEFA5	Q01523	527
DEFB106B	USP17L4	A6NCW7	524
DEFB106B	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

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

Classification	Count (floor)
Pathogenic	0
Likely pathogenic	0
Uncertain significance	8
Likely benign	1
Benign	0

Top pathogenic / likely-pathogenic (0)

SpliceAI

155 predictions. Top by Δscore:

Variant	Effect	Δscore
8:7486201:A:AC	donor_gain	0.9400
8:7486231:T:TA	donor_gain	0.8800
8:7483167:C:CT	acceptor_gain	0.8700
8:7485586:C:T	acceptor_gain	0.8000
8:7486328:TTTTA:T	donor_loss	0.8000
8:7486329:TTTA:T	donor_loss	0.8000
8:7486330:TTACC:T	donor_loss	0.8000
8:7486331:TAC:T	donor_loss	0.8000
8:7486332:A:AC	donor_loss	0.8000
8:7486333:C:CT	donor_loss	0.8000
8:7486334:C:A	donor_loss	0.7900
8:7486206:A:C	donor_gain	0.7800
8:7485592:C:CT	acceptor_gain	0.7700
8:7486311:C:A	donor_gain	0.7500
8:7486376:T:TA	donor_gain	0.7500
8:7483415:GCTT:G	acceptor_gain	0.7400
8:7483416:CTTC:C	acceptor_gain	0.7400
8:7486327:ATTTT:A	donor_loss	0.7200
8:7485586:C:CT	acceptor_gain	0.7000
8:7486335:T:A	donor_loss	0.6900
8:7482753:C:CC	acceptor_gain	0.6800
8:7485587:A:T	acceptor_gain	0.6800
8:7486229:CCT:C	donor_gain	0.6600
8:7485593:A:T	acceptor_gain	0.6500
8:7486294:C:CT	donor_gain	0.6500
8:7486204:A:AC	donor_gain	0.6100
8:7486205:C:CC	donor_gain	0.6100
8:7482748:CTTGG:C	acceptor_gain	0.5900
8:7483168:A:T	acceptor_gain	0.5800
8:7486224:TATCA:T	donor_loss	0.5500

AlphaMissense

436 scored. Top likely-pathogenic:

dbSNP variants (sampled 300 via entrez): RS1000147741 (8:7483974 T>A,C), RS1002207963 (8:7484600 C>T), RS1003955156 (8:7485136 A>G), RS1004007523 (8:7486741 A>T), RS1009576230 (8:7483112 G>T), RS1009958083 (8:7483862 A>G,T), RS1014097764 (8:7484005 A>C,G), RS1014481944 (8:7484733 A>C,G), RS1016606954 (8:7486762 G>T), RS1020182723 (8:7483262 A>G), RS1024447216 (8:7484048 AATAAT>A), RS1028016386 (8:7488046 C>T), RS1029658342 (8:7482969 A>C,G), RS1034181281 (8:7483981 T>A), RS1034212318 (8:7483481 A>T)

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

3 total (human), top 3 by PubMed support.

Chemical	Actions (top 5)	PubMed papers
Benzo(a)pyrene	increases methylation	1
Folic Acid	decreases expression	1
Aflatoxin B1	increases methylation	1

Clinical trials (associated diseases)

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