Seroatlas · Human Serome Atlas

DEFB103A

Beta-defensin 103

Also known as: D103A_HUMAN, DEFB-3, DEFB103, DEFB103B, DEFB3, HBD-3, HBD3, HBP-3, HBP3

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

Protein identityUniProt · HPA

UniProt accession
P81534
Gene
DEFB103A
Ensembl
ENSG00000176797
Chromosome
8
Canonical length
67 aa
Protein class
Predicted secreted proteins, Transporters
Secretome location
Secreted in other tissues

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 103, which has broad spectrum antimicrobial activity and may play an important role in innate epithelial defense. [provided by RefSeq, Oct 2014]

Canonical amino-acid sequenceUniProt

67 residues, UniProt reviewed canonical sequence.

>P81534|DEFB103A
     1  MRIHYLLFAL LFLFLVPVPG HGGIINTLQK YYCRVRGGRC AVLSCLPKEE QIGKCSTRGR
    61  KCCRRKK

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against DEFB103A 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
9.5 nTPM

Expression across tissuesHPA

Tissue

  • vagina: 9.5 nTPM
  • salivary gland: 7.6 nTPM
  • tonsil: 7.1 nTPM
  • esophagus: 6.3 nTPM
  • cervix: 4.7 nTPM
  • skin: 3.6 nTPM

Single-cell type

  • adipocytes: 0 nCPM
  • adrenal cortex cells: 0 nCPM
  • adrenal medulla cells: 0 nCPM
  • alveolar cells type 1: 0 nCPM
  • alveolar cells type 2: 0 nCPM
  • astrocytes: 0 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

  • medulla oblongata: 0.2 nTPM
  • amygdala: 0 nTPM
  • basal ganglia: 0 nTPM
  • cerebellum: 0 nTPM
  • cerebral cortex: 0 nTPM
  • choroid plexus: 0 nTPM

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 DEFB103A as an antibody target. Whether an autoantibody or antibody against DEFB103A could matter depends on whether native DEFB103A is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

DEFB103A is annotated as secreted, so native DEFB103A 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 DEFB103A as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/DEFB103A. 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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