Mouse Gene Cldn18 (R15138) Description and Page Index
  Description: claudin 18
RefSeq Summary (NM_019815): 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 a downstream target gene regulated by the T/EBP/NKX2.1 homeodomain transcription factor. Four alternatively spliced transcript variants resulted from alternative promoters and alternative splicing have been identified, which encode two lung-specific isoforms and two stomach-specific isoforms respectively. This gene is also expressed in colons, inner ear and skin, and its expression is increased in both experimental colitis and ulcerative colitis. [provided by RefSeq, Aug 2010].
Transcript (Including UTRs)
   Position: mm8 chr9:99,500,151-99,519,367 Size: 19,217 Total Exon Count: 5 Strand: -
Coding Region
   Position: mm8 chr9:99,502,075-99,519,300 Size: 17,226 Coding Exon Count: 5 

Page IndexSequence and LinksUniProtKB CommentsCTDMicroarray ExpressionRNA Structure
Protein StructureOther SpeciesGO AnnotationsmRNA DescriptionsPathwaysOther Names
Data last updated: 2006-02-27

-  Sequence and Links to Tools and Databases
Genomic Sequence (chr9:99,500,151-99,519,367)mRNA (may differ from genome)Protein (264 aa)
Gene SorterGenome BrowserOther Species FASTAVisiGeneTable SchemaAllen Brain Atlas
BioGPSCGAPEnsemblEntrez GeneGeneCardsGeneNetwork
MGIPubMedStanford SOURCEUniProtKB

-  Comments and Description Text from UniProtKB
DESCRIPTION: RecName: Full=Claudin-18;
FUNCTION: Plays a major role in tight junction-specific obliteration of the intercellular space, through calcium- independent cell-adhesion activity (By similarity).
SUBCELLULAR LOCATION: Cell junction, tight junction. Cell membrane; Multi-pass membrane protein.
SIMILARITY: Belongs to the claudin family.

-  Comparative Toxicogenomics Database (CTD)
  The following chemicals interact with this gene           more ... click here to view the complete list

-  Microarray Expression Data
Expression ratio colors:

GNF Expression Atlas 2 Data from GNF1M Mouse Chip


Rinn et. al Sex Gene Expression Data on MOE430A Chip


GNF Expression Atlas Data from U74b Mouse Chip


Affymetrix All Exon Microarrays


-  mRNA Secondary Structure of 3' and 5' UTRs
RegionFold EnergyBasesEnergy/Base
Display As
5' UTR -19.5067-0.291 Picture PostScript Text
3' UTR -581.431924-0.302 Picture PostScript Text

The RNAfold program from the Vienna RNA Package is used to perform the secondary structure predictions and folding calculations. The estimated folding energy is in kcal/mol. The more negative the energy, the more secondary structure the RNA is likely to have.

-  Protein Domain and Structure Information
  InterPro Domains: Graphical view of domain structure
IPR006187 - Claudin
IPR003928 - Claudin18
IPR017974 - Claudin_CS
IPR004031 - PMP22/EMP/MP20/Claudin

Pfam Domains:
PF00822 - PMP-22/EMP/MP20/Claudin family

ModBase Predicted Comparative 3D Structure on P56857
The pictures above may be empty if there is no ModBase structure for the protein. The ModBase structure frequently covers just a fragment of the protein. You may be asked to log onto ModBase the first time you click on the pictures. It is simplest after logging in to just click on the picture again to get to the specific info on that model.

-  Orthologous Genes in Other Species
  Orthologies between human, mouse, and rat are computed by taking the best BLASTP hit, and filtering out non-syntenic hits. For more distant species reciprocal-best BLASTP hits are used. Note that the absence of an ortholog in the table below may reflect incomplete annotations in the other species rather than a true absence of the orthologous gene.
HumanRatZebrafishD. melanogasterC. elegansS. cerevisiae
Genome BrowserNo orthologGenome BrowserNo orthologNo orthologNo ortholog
Gene Details     
Gene Sorter     
GenBank Ensembl   
Protein Sequence Protein Sequence   
Alignment Alignment   

-  Gene Ontology (GO) Annotations with Structured Vocabulary
  Molecular Function:
GO:0005198 structural molecule activity
GO:0005515 protein binding
GO:0042802 identical protein binding

Biological Process:
GO:0016338 calcium-independent cell-cell adhesion via plasma membrane cell-adhesion molecules
GO:0045471 response to ethanol
GO:0045779 negative regulation of bone resorption
GO:0048565 digestive tract development
GO:0071847 TNFSF11-mediated signaling pathway
GO:1900181 negative regulation of protein localization to nucleus
GO:2001205 negative regulation of osteoclast development

Cellular Component:
GO:0005886 plasma membrane
GO:0005923 bicellular tight junction
GO:0016020 membrane
GO:0016021 integral component of membrane
GO:0030054 cell junction

-  Descriptions from all associated GenBank mRNAs
  AF221068 - Mus musculus Claudin-18 mRNA, complete cds.
AK033657 - Mus musculus adult male cecum cDNA, RIKEN full-length enriched library, clone:9130209K06 product:CLAUDIN-18A2.1, full insert sequence.
AF349450 - Mus musculus claudin-18A1.2 mRNA, complete cds, alternatively spliced.
AF349451 - Mus musculus claudin-18A2.1 mRNA, complete cds, alternatively spliced.
AF349453 - Mus musculus claudin-18A2.2 mRNA, complete cds, alternatively spliced.
BC140209 - Synthetic construct Mus musculus clone IMAGE:100014220, MGC:173315 claudin 18 (Cldn18) mRNA, encodes complete protein.
BC141602 - Synthetic construct Mus musculus clone IMAGE:100014616, MGC:175448 claudin 18 (Cldn18) mRNA, encodes complete protein.

-  Biochemical and Signaling Pathways
  KEGG - Kyoto Encyclopedia of Genes and Genomes
mmu04514 - Cell adhesion molecules (CAMs)
mmu04530 - Tight junction
mmu04670 - Leukocyte transendothelial migration

-  Other Names for This Gene
  Alternate Gene Symbols: AF221068
UCSC ID: NM_019815
RefSeq Accession: NM_019815
Protein: P56857 (aka CLD18_MOUSE or CLDI_MOUSE)
CCDS: CCDS23437.1

-  Methods, Credits, and Use Restrictions
  Click here for details on how this gene model was made and data restrictions if any.