Seroatlas · Human Serome Atlas

CLDN23

Claudin-23

Also known as: CLD23_HUMAN, CLDNL

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

Protein identityUniProt · HPA

UniProt accession: Q96B33
Gene: CLDN23
Ensembl: ENSG00000253958
Chromosome: 8
Canonical length: 292 aa
Protein class: Predicted membrane proteins, Transporters
Subcellular location: Vesicles,Plasma membrane,Cell Junctions

OverviewNCBI Gene

This gene encodes a member of the claudin family. Claudins are integral membrane proteins and components of tight junction strands. Tight junction strands serve as a physical barrier to prevent solutes and water from passing freely through the paracellular space between epithelial or endothelial cell sheets, and also play critical roles in maintaining cell polarity and signal transductions. This gene is expressed in germinal center B-cells, placenta and stomach as well as in colon tumor. This gene is down-regulated in intestinal type gastric cancer. [provided by RefSeq, Aug 2010]

Canonical amino-acid sequenceUniProt

292 residues, UniProt reviewed canonical sequence.

>Q96B33|CLDN23
     1  MRTPVVMTLG MVLAPCGLLL NLTGTLAPGW RLVKGFLNQP VDVELYQGLW DMCREQSSRE
    61  RECGQTDQWG YFEAQPVLVA RALMVTSLAA TVLGLLLASL GVRCWQDEPN FVLAGLSGVV
   121  LFVAGLLGLI PVSWYNHFLG DRDVLPAPAS PVTVQVSYSL VLGYLGSCLL LLGGFSLALS
   181  FAPWCDERCR RRRKGPSAGP RRSSVSTIQV EWPEPDLAPA IKYYSDGQHR PPPAQHRKPK
   241  PKPKVGFPMP RPRPKAYTNS VDVLDGEGWE SQDAPSCSTH PCDSSLPCDS DL

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against CLDN23 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): 0.43
Highest tissue expression: 15 nTPM

Expression across tissuesHPA

Tissue

colon: 15 nTPM
stomach: 15 nTPM
skin: 13 nTPM
liver: 9.9 nTPM
small intestine: 9.6 nTPM
rectum: 6.4 nTPM

Single-cell type

papillary tip epithelial cells: 4.4 nCPM
microglia: 1.9 nCPM
renal collecting duct principal cells: 1.2 nCPM
loop of henle epithelial cells: 1 nCPM
podocytes: 1 nCPM
ependymal cells: 0.9 nCPM

Immune cell

plasmacytoid DC: 1.4 nTPM
myeloid DC: 1.3 nTPM
classical monocyte: 0.9 nTPM
intermediate monocyte: 0.9 nTPM
eosinophil: 0.3 nTPM
total PBMC: 0.3 nTPM

Brain region

choroid plexus: 4.6 nTPM
white matter: 1 nTPM
thalamus: 0.8 nTPM
medulla oblongata: 0.7 nTPM
cerebral cortex: 0.6 nTPM
midbrain: 0.6 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): 1.75
gnomAD pLI: 0
gnomAD missense Z: -0.81
DepMap mean gene effect: 0.14
DepMap dependency class: none

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 4% 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 CLDN23 as an antibody target. Whether an autoantibody or antibody against CLDN23 could matter depends on whether native CLDN23 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

CLDN23 is annotated at the cell surface, where native CLDN23 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 CLDN23 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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