Seroatlas · Human Serome Atlas

DEFB4A

Defensin beta 4A

Also known as: DEFB-2, DEFB102, DEFB2, DEFB4, DEFB4B, DEFB4P, DFB4A_HUMAN, HBD-2, SAP1

Cross-references: UniProt · Ensembl · Human Protein Atlas · GeneCards · NCBI Gene

Protein identityUniProt · HPA

UniProt accession
O15263
Gene
DEFB4A
Ensembl
ENSG00000171711
Chromosome
8
Canonical length
64 aa
Protein class
Predicted secreted proteins, Transporters
Secretome location
Secreted in other tissues
Quaternary structure
Homodimer

OverviewNCBI Gene

Defensins form a family of microbicidal and cytotoxic peptides made by neutrophils. Members of the defensin family are highly similar in protein sequence. This gene encodes defensin, beta 4, an antibiotic peptide which is locally regulated by inflammation. [provided by RefSeq, Oct 2014]

Canonical amino-acid sequenceUniProt

64 residues, UniProt reviewed canonical sequence.

>O15263|DEFB4A
     1  MRVLYLLFSF LFIFLMPLPG VFGGIGDPVT CLKSGAICHP VFCPRRYKQI GTCGLPGTKC
    61  CKKP

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against DEFB4A can act on the native protein depends on physical access: surface and secreted proteins are reachable by circulating antibodies, intracellular proteins usually are not.

Antibody reachability
Secreted
Secreted
Yes
Transmembrane segments
0
Mean surface accessibility (rSASA)
0.47
Highest tissue expression
151 nTPM

Expression across tissuesHPA

Tissue

  • esophagus: 151 nTPM
  • cervix: 72 nTPM
  • salivary gland: 30 nTPM
  • vagina: 15 nTPM
  • lung: 10 nTPM
  • stomach: 7.8 nTPM

Single-cell type

  • esophageal apical cells: 147 nCPM
  • foveolar cells: 68 nCPM
  • endometrial secretory cells: 26 nCPM
  • suprabasal keratinocytes: 20 nCPM
  • esophageal suprabasal cells: 16 nCPM
  • ocular epithelial cells: 15 nCPM

Immune cell

  • basophil: 0 nTPM
  • classical monocyte: 0 nTPM
  • eosinophil: 0 nTPM
  • gdT-cell: 0 nTPM
  • intermediate monocyte: 0 nTPM
  • MAIT T-cell: 0 nTPM

Brain region

  • amygdala: 0 nTPM
  • basal ganglia: 0 nTPM
  • cerebellum: 0 nTPM
  • cerebral cortex: 0 nTPM
  • choroid plexus: 0 nTPM
  • hippocampal formation: 0 nTPM

Genetic constraint and essentialitygnomAD · DepMap

Does the body need this protein intact? Low LOEUF or a strong DepMap dependency means loss or blockade of the protein is likely to be felt.

gnomAD LOEUF (loss-of-function intolerance)
1.97
gnomAD pLI
0
gnomAD missense Z
-0.63

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 3% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

Molecular functions

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads DEFB4A as an antibody target. Whether an autoantibody or antibody against DEFB4A could matter depends on whether native DEFB4A is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

DEFB4A is annotated as secreted, so native DEFB4A circulates and is directly accessible to antibodies. Secreted and cell-surface proteins are the autoantibody targets most likely to act like drugs, blocking or depleting the native protein.

Annotation status

The present source text does not explicitly label DEFB4A as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/DEFB4A. Study-independent annotations aggregated from UniProt, Human Protein Atlas, PubMed, IEDB, Pfam, InterPro, Gene Ontology, AlphaFold, gnomAD, DepMap, ClinVar, TCGA. Catalog release seroatlas-reviewed-human-uniprot-20260313.

Seroatlas is the reference for exploring autoantibody and antibody serology at the human-protein level: the autoreactome and human serome, multiplex serology (HuProt, HuScan, VirScan, PhIP-Seq).

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