Seroatlas · Human Serome Atlas

CLDN4

Claudin-4

Also known as: CLD4_HUMAN, CPE-R, CPETR, CPETR1, hCPE-R, WBSCR8

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

Protein identityUniProt · HPA

UniProt accession
O14493
Gene
CLDN4
Ensembl
ENSG00000189143
Chromosome
7
Canonical length
209 aa
Protein class
Cancer-related genes, Disease related genes, Human disease related genes, Potential drug targets, Predicted membrane proteins, Transporters
Subcellular location
Plasma membrane

OverviewNCBI Gene

The protein encoded by this intronless gene belongs to the claudin family. Claudins are integral membrane proteins that are components of the epithelial cell tight junctions, which regulate movement of solutes and ions through the paracellular space. This protein is a high-affinity receptor for Clostridium perfringens enterotoxin (CPE) and may play a role in internal organ development and function during pre- and postnatal life. This gene is deleted in Williams-Beuren syndrome, a neurodevelopmental disorder affecting multiple systems. [provided by RefSeq, Sep 2013]

Canonical amino-acid sequenceUniProt

209 residues, UniProt reviewed canonical sequence.

>O14493|CLDN4
     1  MASMGLQVMG IALAVLGWLA VMLCCALPMW RVTAFIGSNI VTSQTIWEGL WMNCVVQSTG
    61  QMQCKVYDSL LALPQDLQAA RALVIISIIV AALGVLLSVV GGKCTNCLED ESAKAKTMIV
   121  AGVVFLLAGL MVIVPVSWTA HNIIQDFYNP LVASGQKREM GASLYVGWAA SGLLLLGGGL
   181  LCCNCPPRTD KPYSAKYSAA RSAAASNYV

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against CLDN4 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
4
Mean surface accessibility (rSASA)
0.33
Highest tissue expression
318 nTPM

Expression across tissuesHPA

Tissue

  • esophagus: 318 nTPM
  • urinary bladder: 283 nTPM
  • colon: 265 nTPM
  • salivary gland: 215 nTPM
  • skin: 188 nTPM
  • small intestine: 180 nTPM

Single-cell type

  • esophageal apical cells: 5,919 nCPM
  • epididymal basal cells: 4,215 nCPM
  • ocular epithelial cells: 3,935 nCPM
  • urothelial cells: 3,470 nCPM
  • breast secretory cells: 2,532 nCPM
  • endometrial glandular cells: 2,507 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

  • choroid plexus: 11 nTPM
  • midbrain: 4.4 nTPM
  • cerebellum: 2.7 nTPM
  • medulla oblongata: 2 nTPM
  • pons: 1.8 nTPM
  • thalamus: 1.5 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)
1.83
gnomAD pLI
0
gnomAD missense Z
0.76
DepMap mean gene effect
0.04
DepMap dependency class
none

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 6% 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 CLDN4 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 CLDN4 as an antibody target. Whether an autoantibody or antibody against CLDN4 could matter depends on whether native CLDN4 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

CLDN4 is annotated at the cell surface, where native CLDN4 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 CLDN4 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/CLDN4. 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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