Seroatlas · Human Serome Atlas

BTBD18

BTB/POZ domain-containing protein 18

Also known as: BTBDI_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
B2RXH4
Gene
BTBD18
Ensembl
ENSG00000233436
Chromosome
11
Canonical length
712 aa
Protein class
Predicted intracellular proteins
Subcellular location
Nucleoplasm,Vesicles,Plasma membrane

OverviewNCBI Gene

Predicted to be involved in male meiosis I; piRNA transcription; and spermatogenesis. Predicted to act upstream of with a positive effect on transposable element silencing. Predicted to be active in nucleus. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

712 residues, UniProt reviewed canonical sequence.

>B2RXH4|BTBD18
     1  MCSPASPKIL YRNPRFLRLA FLQLHHQQQS DVFCDVLLQA EGEAVPAHCC ILSACSPFFT
    61  ERLERERPAQ GGKVVLELGG LKISTLRKLV DFLYTSEMEV SQEEAQDVLS AARQLRVSEL
   121  ESLQLEGGKL VKAPQGRRLN RECLQPTSAA PISARVVTPS HHPHTPLPTN QTPCPLGAIR
   181  LKSLGKEEGP QENNRQNADN LSGTLLLKRK ARACPTPQEK NSSPSSHSQE PRENKNDTAL
   241  DPTVLSPPSL YPSVDKHLLP RKIRLSRSKP SPGICTSKPS SILSGSSSVP ATPGRRLWRQ
   301  RSVNKETPED KPKPGRASPL QSTPNPSGLG KTGGSRKRSP EVRAPNSDSA EEGQVGRVKL
   361  RKIVNGTCWE VVQETPLKNT QDSPQIPDPG GDFQEPSGTQ PFSSNEQEMS PTRTELCQDS
   421  PMCTKLQDIL VSASHSPDHP VVKSEFESSP ELVEKEPMLA IDCREPYAFD TALLEQPCEA
   481  EEYRITSAAA TSELEEILDF MLCGSDIEPP IGSLESPGAE GCRTPTYHLT ETGKNWIEGE
   541  EWCLPDMELW PRELTELEKE PAGENRGPTE LLSPLVMPSE VSEVLSVGGR WTPDLEITSS
   601  QPLDGQEDKL LHVSSLDTPQ RSYGDLSPPC SNWVETGLEV SLTTDELLYP SPKAGKEVSG
   661  HSELLGSLPA SSEEEEIDVV DWTAEGRLVP TTVPSVWPDP SSESETEVDI LT

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against BTBD18 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
Intracellular
Secreted
No
Transmembrane segments
0
Mean surface accessibility (rSASA)
0.65
Highest tissue expression
2.1 nTPM

Expression across tissuesHPA

Tissue

  • testis: 2.1 nTPM
  • cerebellum: 0.2 nTPM
  • skin: 0.2 nTPM
  • basal ganglia: 0.1 nTPM
  • bone marrow: 0.1 nTPM
  • cerebral cortex: 0.1 nTPM

Single-cell type

  • epicardial cells: 71 nCPM
  • cardiomyocytes: 47 nCPM
  • myonuclei: 18 nCPM
  • adipocytes: 16 nCPM
  • medullary thymic epithelial cells: 12 nCPM
  • retinal amacrine cells: 9.6 nCPM

Immune cell

  • naive B-cell: 0.4 nTPM
  • naive CD4 T-cell: 0.3 nTPM
  • intermediate monocyte: 0.2 nTPM
  • memory CD4 T-cell: 0.2 nTPM
  • classical monocyte: 0.1 nTPM
  • memory B-cell: 0.1 nTPM

Brain region

  • cerebellum: 8.2 nTPM
  • cerebral cortex: 6.6 nTPM
  • white matter: 5.5 nTPM
  • amygdala: 5.4 nTPM
  • basal ganglia: 5.2 nTPM
  • hippocampal formation: 5.2 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)
0.21
gnomAD pLI
1
gnomAD missense Z
1.65
DepMap mean gene effect
0.07
DepMap dependency class
selective

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

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads BTBD18 as an antibody target. Whether an autoantibody or antibody against BTBD18 could matter depends on whether native BTBD18 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

BTBD18 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 BTBD18 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/BTBD18. 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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