Seroatlas · Human Serome Atlas

CLDN3

Claudin-3

Also known as: C7orf1, CLD3_HUMAN, CPE-R2, CPETR2, HRVP1, RVP1

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

Protein identityUniProt · HPA

UniProt accession
O15551
Gene
CLDN3
Ensembl
ENSG00000165215
Chromosome
7
Canonical length
220 aa
Protein class
Cancer-related genes, Disease related genes, Human disease related genes, Potential drug targets, Predicted membrane proteins, Transporters
Subcellular location
Cell Junctions
Quaternary structure
Homopolymer

OverviewNCBI Gene

Tight junctions represent one mode of cell-to-cell adhesion in epithelial or endothelial cell sheets, forming continuous seals around cells and serving as a physical barrier to prevent solutes and water from passing freely through the paracellular space. These junctions are comprised of sets of continuous networking strands in the outwardly facing cytoplasmic leaflet, with complementary grooves in the inwardly facing extracytoplasmic leaflet. The protein encoded by this intronless gene, a member of the claudin family, is an integral membrane protein and a component of tight junction strands. It is also a low-affinity receptor for Clostridium perfringens enterotoxin, and shares aa sequence similarity with a putative apoptosis-related protein found in rat. [provided by RefSeq, Jul 2008]

Canonical amino-acid sequenceUniProt

220 residues, UniProt reviewed canonical sequence.

>O15551|CLDN3
     1  MSMGLEITGT ALAVLGWLGT IVCCALPMWR VSAFIGSNII TSQNIWEGLW MNCVVQSTGQ
    61  MQCKVYDSLL ALPQDLQAAR ALIVVAILLA AFGLLVALVG AQCTNCVQDD TAKAKITIVA
   121  GVLFLLAALL TLVPVSWSAN TIIRDFYNPV VPEAQKREMG AGLYVGWAAA ALQLLGGALL
   181  CCSCPPREKK YTATKVVYSA PRSTGPGASL GTGYDRKDYV

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against CLDN3 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)
0.35
Highest tissue expression
249 nTPM

Expression across tissuesHPA

Tissue

  • colon: 249 nTPM
  • small intestine: 163 nTPM
  • thyroid gland: 111 nTPM
  • pancreas: 93 nTPM
  • salivary gland: 72 nTPM
  • prostate: 54 nTPM

Single-cell type

  • enterocytes: 2,815 nCPM
  • colonocytes: 2,781 nCPM
  • goblet cells: 1,660 nCPM
  • enteric transient amplifying cells: 1,532 nCPM
  • endometrial glandular cells: 1,469 nCPM
  • endometrial luminal cells: 1,459 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: 81 nTPM
  • cerebellum: 10 nTPM
  • midbrain: 5.2 nTPM
  • medulla oblongata: 4.1 nTPM
  • hypothalamus: 3.8 nTPM
  • hippocampal formation: 3.2 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)
0.76
gnomAD pLI
0.52
gnomAD missense Z
1.33
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

InteractionsUniProt · HPA

Protein binding partners of CLDN3 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 CLDN3 as an antibody target. Whether an autoantibody or antibody against CLDN3 could matter depends on whether native CLDN3 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

CLDN3 is annotated at the cell surface, where native CLDN3 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 CLDN3 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/CLDN3. 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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