Seroatlas · Human Serome Atlas

BTN3A3

Butyrophilin subfamily 3 member A3

Also known as: BT3A3_HUMAN, BTF3, BTN3.3

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

Protein identityUniProt · HPA

UniProt accession
O00478
Gene
BTN3A3
Ensembl
ENSG00000111801
Chromosome
6
Canonical length
584 aa
Protein class
Predicted intracellular proteins, Predicted membrane proteins
Subcellular location
Nucleoplasm,Nuclear bodies,Vesicles,Plasma membrane,Cytosol
Quaternary structure
Homodimer

OverviewNCBI Gene

The butyrophilin (BTN) genes are a group of major histocompatibility complex (MHC)-associated genes that encode type I membrane proteins with 2 extracellular immunoglobulin (Ig) domains and an intracellular B30.2 (PRYSPRY) domain. Three subfamilies of human BTN genes are located in the MHC class I region: the single-copy BTN1A1 gene (MIM 601610) and the BTN2 (e.g., BTN2A1; MIM 613590) and BTN3 (e.g., BNT3A3) genes, which have undergone tandem duplication, resulting in 3 copies of each (summary by Smith et al., 2010 [PubMed 20208008]).[supplied by OMIM, Nov 2010]

Canonical amino-acid sequenceUniProt

584 residues, UniProt reviewed canonical sequence.

>O00478|BTN3A3
     1  MKMASSLAFL LLNFHVSLFL VQLLTPCSAQ FSVLGPSGPI LAMVGEDADL PCHLFPTMSA
    61  ETMELRWVSS SLRQVVNVYA DGKEVEDRQS APYRGRTSIL RDGITAGKAA LRIHNVTASD
   121  SGKYLCYFQD GDFYEKALVE LKVAALGSDL HIEVKGYEDG GIHLECRSTG WYPQPQIKWS
   181  DTKGENIPAV EAPVVADGVG LYAVAASVIM RGSSGGGVSC IIRNSLLGLE KTASISIADP
   241  FFRSAQPWIA ALAGTLPISL LLLAGASYFL WRQQKEKIAL SRETEREREM KEMGYAATEQ
   301  EISLREKLQE ELKWRKIQYM ARGEKSLAYH EWKMALFKPA DVILDPDTAN AILLVSEDQR
   361  SVQRAEEPRD LPDNPERFEW RYCVLGCENF TSGRHYWEVE VGDRKEWHIG VCSKNVERKK
   421  GWVKMTPENG YWTMGLTDGN KYRALTEPRT NLKLPEPPRK VGIFLDYETG EISFYNATDG
   481  SHIYTFPHAS FSEPLYPVFR ILTLEPTALT ICPIPKEVES SPDPDLVPDH SLETPLTPGL
   541  ANESGEPQAE VTSLLLPAHP GAEVSPSATT NQNHKLQART EALY

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against BTN3A3 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
Cell surface
Secreted
No
Transmembrane segments
1
Mean surface accessibility (rSASA)
0.37
Highest tissue expression
44 nTPM

Expression across tissuesHPA

Tissue

  • spleen: 44 nTPM
  • lung: 32 nTPM
  • lymph node: 27 nTPM
  • ovary: 24 nTPM
  • tonsil: 21 nTPM
  • thymus: 20 nTPM

Single-cell type

  • kupffer cells: 40 nCPM
  • late spermatids: 32 nCPM
  • nk-cells: 28 nCPM
  • t-cells: 24 nCPM
  • vascular endothelial cells: 19 nCPM
  • b-cells: 18 nCPM

Immune cell

  • memory CD8 T-cell: 56 nTPM
  • gdT-cell: 55 nTPM
  • naive CD8 T-cell: 49 nTPM
  • basophil: 49 nTPM
  • T-reg: 46 nTPM
  • NK-cell: 46 nTPM

Brain region

  • medulla oblongata: 13 nTPM
  • spinal cord: 11 nTPM
  • hypothalamus: 11 nTPM
  • white matter: 9.4 nTPM
  • choroid plexus: 9 nTPM
  • pons: 8 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)
1.67
gnomAD pLI
0
gnomAD missense Z
-0.15
DepMap mean gene effect
0.08
DepMap dependency class
none

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 5% 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 BTN3A3 as an antibody target. Whether an autoantibody or antibody against BTN3A3 could matter depends on whether native BTN3A3 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

BTN3A3 is annotated at the cell surface, where native BTN3A3 is exposed to circulating antibodies and is a prime autoantibody target that could block, deplete, or overstimulate it.

Annotation status

The present source text does not explicitly label BTN3A3 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/BTN3A3. 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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