CLDN18

Claudin-18. UniProt annotates extracellular residues 28–80, 144–174.

Predicted protein structure

A downloaded AlphaFold model connects the CLDN18 sequence to its predicted three-dimensional structure.

RNA expression in tumor samples

Median CLDN18 RNA expression by tumor type, measured in RSEM units. The study selected these samples using microsatellite-stability score thresholds.

Mucinous tumors37 samples9.8

Other tumor types438 samples1.2

Compare the sample groups · cBioPortal measurements (JSON)

Sequence & binding sites

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Sequence annotations and source records

Canonical sequence and topology

Target ID: T-ENSG00000066405
UniProt accession: P56856
Sequence state: available
Canonical sequence: Yes
Length in amino acids: 261
Sequence SHA-256: 89c388e151022937dd56f7be9599e2f03f07e579e7c1308d4112f0c386b1491c

View and select the full canonical sequence

Canonical amino-acid sequence

MSTTTCQVVAFLLSILGLAGCIAATGMDMWSTQDLYDNPVTSVFQYEGLWRSCVRQSSGFTECRPYFTILGLPAMLQAVRALMIVGIVLGAIGLLVSIFALKCIRIGSMEDSAKANMTLTSGIMFIVSGLCAIAGVSVFANMLVTNFWMSTANMYTGMGGMVQTVQTRYTFGAALFVGWVAGGLTLIGGVMMCIACRGLAPEETNYKAVSYHASGHSVAYKPGGFKASTGFGSNTKNKKIYDGGARTEDEVQSYPSKHDYV

Sequence positions 1–261

Gray shows the full canonical sequence. Colored spans mark the listed intervals.

Membrane-spanning segments

7–27 (Helical); 81–101 (Helical); 123–143 (Helical); 175–195 (Helical)

Source-annotated domains

1–6 (Cytoplasmic); 28–80 (Extracellular); 102–122 (Cytoplasmic); 144–174 (Extracellular); 196–261 (Cytoplasmic)

Source-annotated extracellular intervals

28–80; 144–174

UniProt annotates the following extracellular intervals.

One-based positions include both interval endpoints.
Start	End	Length	Sequence and source
28	80	53	Sequence and source Basis reviewed-uniprot-topological-domain Evidence class source-annotated-topology Sequence SHA-256 2cfa4c45314f72356b167e6363926e4d023594dce5b50b583851a12d379aa8f6 Amino-acid sequence for this intervalDMWSTQDLYDNPVTSVFQYEGLWRSCVRQSSGFTECRPYFTILGLPAMLQAVR
144	174	31	Sequence and source Basis reviewed-uniprot-topological-domain Evidence class source-annotated-topology Sequence SHA-256 f232105a166d351c3055d9d9ed6ef1b704984bb4001cdea111c93097b02f7c92 Amino-acid sequence for this intervalVTNFWMSTANMYTGMGGMVQTVQTRYTFGAA

Sequence and topology sources

Source role: canonical-sequence
Source: alphafold-db-canonical-uniprot-field
Extracted field: uniprotSequence
Source row accession: Not recorded

Download source snapshot

Open sequence source

Source role: reviewed-topology
Source: UniProt reviewed human surface-field snapshot
Extracted field: Not recorded
Source row accession: P56856

Download source snapshot (gzip)

subcellular_location: SUBCELLULAR LOCATION: Cell junction, tight junction {ECO:0000250|UniProtKB:P56857}. Cell membrane {ECO:0000250|UniProtKB:P56857}; Multi-pass membrane protein {ECO:0000255}. Note=Localizes to tight junctions in epithelial cells. {ECO:0000250|UniProtKB:P56857}.; SUBCELLULAR LOCATION: [Isoform A1]: Cell junction, tight junction {ECO:0000250|UniProtKB:P56857}.; SUBCELLULAR LOCATION: [Isoform A2]: Cell junction, tight junction {ECO:0000250|UniProtKB:P56857}. Lateral cell membrane {ECO:0000250|UniProtKB:P56857}.
transmembrane: TRANSMEM 7..27; /note="Helical"; /evidence="ECO:0000255"; TRANSMEM 81..101; /note="Helical"; /evidence="ECO:0000255"; TRANSMEM 123..143; /note="Helical"; /evidence="ECO:0000255"; TRANSMEM 175..195; /note="Helical"; /evidence="ECO:0000255"
topological_domain: TOPO_DOM 1..6; /note="Cytoplasmic"; /evidence="ECO:0000255"; TOPO_DOM 28..80; /note="Extracellular"; /evidence="ECO:0000255"; TOPO_DOM 102..122; /note="Cytoplasmic"; /evidence="ECO:0000255"; TOPO_DOM 144..174; /note="Extracellular"; /evidence="ECO:0000255"; TOPO_DOM 196..261; /note="Cytoplasmic"; /evidence="ECO:0000255"
signal_peptide: Not recorded
lipidation: Not recorded

Download all canonical target sequences (FASTA)

Protein identity and location

Protein: Claudin-18
Protein location: Transmembrane protein
Canonical sequence: P56856 · 261 amino acids
Extracellular region: UniProt annotates extracellular residues 28–80, 144–174.

Expression in normal tissues

RNA specificity: Group enriched
RNA distribution: Detected in some
RNA tissue-specific nTPM: lung: 237.8; stomach 1: 684.2
Protein specificity: Tissue enriched
Protein distribution: Detected in some
Immunohistochemistry reliability: Enhanced
Immunofluorescence reliability: Approved
Protein tissue-specific intensity: lung: 7,482,438.2
Tissue cell-type enrichment: Lung - Alveolar cells type 1, Testis - Spermatocytes
Subcellular location: Cell Junctions

Human Protein Atlas: CLDN18

Structures

A predicted target model is available.

Browse related molecular views

Sources and downloads

UniProt protein record Target measurements (JSON)Sequence annotations (JSON)Target sequences (FASTA)

CLDN18 · ENSG00000066405 · P56856