Seroatlas · Human Serome Atlas

BCAP31

B-cell receptor-associated protein 31

Also known as: 6C6-Ag, BAP31, BAP31_HUMAN, CDM, DXS1357E

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

Protein identityUniProt · HPA

UniProt accession
P51572
Gene
BCAP31
Ensembl
ENSG00000185825
Chromosome
X
Canonical length
246 aa
Protein class
Disease related genes, Human disease related genes, Metabolic proteins, Potential drug targets, Predicted membrane proteins, Transporters
Subcellular location
Endoplasmic reticulum
Quaternary structure
Homodimer

OverviewNCBI Gene

This gene encodes a member of the B-cell receptor associated protein 31 superfamily. The encoded protein is a multi-pass transmembrane protein of the endoplasmic reticulum that is involved in the anterograde transport of membrane proteins from the endoplasmic reticulum to the Golgi and in caspase 8-mediated apoptosis. Microdeletions in this gene are associated with contiguous ABCD1/DXS1375E deletion syndrome (CADDS), a neonatal disorder. Alternative splicing of this gene results in multiple transcript variants. Two related pseudogenes have been identified on chromosome 16. [provided by RefSeq, Jan 2012]

Canonical amino-acid sequenceUniProt

246 residues, UniProt reviewed canonical sequence.

>P51572|BCAP31
     1  MSLQWTAVAT FLYAEVFVVL LLCIPFISPK RWQKIFKSRL VELLVSYGNT FFVVLIVILV
    61  LLVIDAVREI RKYDDVTEKV NLQNNPGAME HFHMKLFRAQ RNLYIAGFSL LLSFLLRRLV
   121  TLISQQATLL ASNEAFKKQA ESASEAAKKY MEENDQLKKG AAVDGGKLDV GNAEVKLEEE
   181  NRSLKADLQK LKDELASTKQ KLEKAENQVL AMRKQSEGLT KEYDRLLEEH AKLQAAVDGP
   241  MDKKEE

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against BCAP31 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
Other membrane
Secreted
No
Transmembrane segments
3
Mean surface accessibility (rSASA)
0.44
Highest tissue expression
393 nTPM

Expression across tissuesHPA

Tissue

  • choroid plexus: 393 nTPM
  • adipose tissue: 295 nTPM
  • esophagus: 255 nTPM
  • adrenal gland: 253 nTPM
  • pancreas: 251 nTPM
  • breast: 249 nTPM

Single-cell type

  • syncytiotrophoblasts: 628 nCPM
  • extravillous trophoblasts: 575 nCPM
  • cytotrophoblasts: 513 nCPM
  • esophageal apical cells: 501 nCPM
  • migrating cytotrophoblasts: 476 nCPM
  • early primary spermatocytes: 400 nCPM

Immune cell

  • total PBMC: 1,111 nTPM
  • plasmacytoid DC: 668 nTPM
  • non-classical monocyte: 635 nTPM
  • basophil: 632 nTPM
  • neutrophil: 627 nTPM
  • intermediate monocyte: 536 nTPM

Brain region

  • choroid plexus: 180 nTPM
  • pons: 167 nTPM
  • hypothalamus: 159 nTPM
  • medulla oblongata: 156 nTPM
  • thalamus: 152 nTPM
  • midbrain: 150 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about BCAP31.

Disease | AllUniProt

Conditions BCAP31 is implicated in, by any mechanism.

  • Deafness, dystonia, and cerebral hypomyelination (DDCH) MIM:300475

Disease | GeneticClinVar

17 pathogenic / likely-pathogenic of 264 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

Disease | ImmuneIEDB

Conditions an epitope on BCAP31 was assayed in.

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)
0.65
gnomAD pLI
0.43
gnomAD missense Z
1.3
DepMap mean gene effect
-0.2
DepMap dependency class
selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 7% 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

InteractionsUniProt · HPA

Protein binding partners of BCAP31 in the human serome: UniProt-annotated complex subunits plus reported interactors. Each links to its own Seroatlas record.

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads BCAP31 as an antibody target. Whether an autoantibody or antibody against BCAP31 could matter depends on whether native BCAP31 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

BCAP31 is annotated as predominantly intracellular. Intracellular proteins are common autoantibody markers, becoming visible to the immune system after cell injury or altered processing, but are usually markers of disease rather than direct drivers.

Annotation status

The present source text does not explicitly label BCAP31 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/BCAP31. 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).

© 2026 · Seroatlas, Discover Oregon LLC · Terms of use

Loading the interactive Seroatlas protein explorer...