P56856 (CLD18_HUMAN) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
Claudin-18

Gene names

Name:	CLDN18
ORF Names:	UNQ778/PRO1572

Organism

Homo sapiens (Human) [Reference proteome]

Taxonomic identifier

9606 [NCBI]

Taxonomic lineage

cellular organisms › Eukaryota › Opisthokonta › Metazoa › Eumetazoa › Bilateria › Deuterostomia › Chordata › Craniata › Vertebrata › Gnathostomata › Teleostomi › Euteleostomi › Sarcopterygii › Tetrapoda › Amniota › Mammalia › Theria › Eutheria › Euarchontoglires › Primates › Haplorrhini › Simiiformes › Catarrhini › Hominoidea › Hominidae › Homininae › Homo

Protein attributes

Sequence length	261 AA.
Sequence status	Complete.
Protein existence	Evidence at protein level

General annotation (Comments)

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.
Tissue specificity	Concentrated at the cell-cell borders of epithelial cells.
Sequence similarities	Belongs to the claudin family.

Ontologies

Keywords
Cellular component	Cell junction Cell membrane Membrane Tight junction
Coding sequence diversity	Alternative splicing Polymorphism
Domain	Transmembrane Transmembrane helix
PTM	Phosphoprotein
Technical term	Complete proteome Reference proteome
Gene Ontology (GO)
Biological_process	calcium-independent cell-cell adhesion Inferred from sequence or structural similarity. Source: UniProtKB tight junction assembly Traceable author statement. Source: Reactome
Cellular_component	integral to membrane Inferred from electronic annotation. Source: UniProtKB-KW plasma membrane Inferred from electronic annotation. Source: UniProtKB-SubCell tight junction Inferred from sequence or structural similarity. Source: UniProtKB
Molecular_function	identical protein binding Inferred from sequence or structural similarity. Source: UniProtKB structural molecule activity Inferred from electronic annotation. Source: InterPro
Complete GO annotation...

Alternative products

This entry describes 2 isoforms produced by alternative splicing. [Align] [Select]

Isoform A1 (identifier: P56856-1)

This isoform has been chosen as the 'canonical' sequence. All positional information in this entry refers to it. This is also the sequence that appears in the downloadable versions of the entry.

Isoform A2 (identifier: P56856-2)

The sequence of this isoform differs from the canonical sequence as follows:
     1-69: MSTTTCQVVA...FTECRPYFTI → MAVTACQGLG...FTECRGYFTL

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	1 – 261	261	Claudin-18		PRO_0000144779
Regions
	Topological domain	1 – 6	6	Cytoplasmic Potential
	Transmembrane	7 – 27	21	Helical; Potential
	Topological domain	28 – 80	53	Extracellular Potential
	Transmembrane	81 – 101	21	Helical; Potential
	Topological domain	102 – 122	21	Cytoplasmic Potential
	Transmembrane	123 – 143	21	Helical; Potential
	Topological domain	144 – 174	31	Extracellular Potential
	Transmembrane	175 – 195	21	Helical; Potential
	Topological domain	196 – 261	66	Cytoplasmic Potential
Amino acid modifications
	Modified residue	247	1	Phosphothreonine By similarity
	Modified residue	253	1	Phosphoserine By similarity
Natural variations
	Alternative sequence	1 – 69	69	MSTTT…PYFTI → MAVTACQGLGFVVSLIGIAG IIAATCMDQWSTQDLYNNPV TAVFNYQGLWRSCVRESSGF TECRGYFTL in isoform A2.		VSP_001102
	Natural variant	149	1	M → L. Corresponds to variant rs17204075 [ dbSNP | Ensembl ].		VAR_033775

Sequences

	Sequence		Length	Mass (Da)
	Isoform A1 [UniParc]. Last modified May 30, 2000. Version 1. Checksum: 4362B590D3C2B387	FASTA	261	27,856
	10 20 30 40 50 60 MSTTTCQVVA FLLSILGLAG CIAATGMDMW STQDLYDNPV TSVFQYEGLW RSCVRQSSGF 70 80 90 100 110 120 TECRPYFTIL GLPAMLQAVR ALMIVGIVLG AIGLLVSIFA LKCIRIGSME DSAKANMTLT 130 140 150 160 170 180 SGIMFIVSGL CAIAGVSVFA NMLVTNFWMS TANMYTGMGG MVQTVQTRYT FGAALFVGWV 190 200 210 220 230 240 AGGLTLIGGV MMCIACRGLA PEETNYKAVS YHASGHSVAY KPGGFKASTG FGSNTKNKKI 250 260 YDGGARTEDE VQSYPSKHDY V
	Isoform A2 [UniParc]. Checksum: DA519D1E57FDFCA7	FASTA	261	27,720
	10 20 30 40 50 60 MAVTACQGLG FVVSLIGIAG IIAATCMDQW STQDLYNNPV TAVFNYQGLW RSCVRESSGF 70 80 90 100 110 120 TECRGYFTLL GLPAMLQAVR ALMIVGIVLG AIGLLVSIFA LKCIRIGSME DSAKANMTLT 130 140 150 160 170 180 SGIMFIVSGL CAIAGVSVFA NMLVTNFWMS TANMYTGMGG MVQTVQTRYT FGAALFVGWV 190 200 210 220 230 240 AGGLTLIGGV MMCIACRGLA PEETNYKAVS YHASGHSVAY KPGGFKASTG FGSNTKNKKI 250 260 YDGGARTEDE VQSYPSKHDY V

References

	« Hide 'large scale' referencesShow 'large scale' references »
[1]	"Claudin-18, a novel downstream target gene for the T/EBP/NKX2.1 homeodomain transcription factor, encodes lung- and stomach-specific isoforms through alternative splicing." Niimi T., Nagashima K., Ward J.M., Minoo P., Zimonjic D.B., Popescu N.C., Kimura S. Mol. Cell. Biol. 21:7380-7390(2001) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA], ALTERNATIVE SPLICING.
[2]	"The secreted protein discovery initiative (SPDI), a large-scale effort to identify novel human secreted and transmembrane proteins: a bioinformatics assessment." Clark H.F., Gurney A.L., Abaya E., Baker K., Baldwin D.T., Brush J., Chen J., Chow B., Chui C., Crowley C., Currell B., Deuel B., Dowd P., Eaton D., Foster J.S., Grimaldi C., Gu Q., Hass P.E. , Heldens S., Huang A., Kim H.S., Klimowski L., Jin Y., Johnson S., Lee J., Lewis L., Liao D., Mark M.R., Robbie E., Sanchez C., Schoenfeld J., Seshagiri S., Simmons L., Singh J., Smith V., Stinson J., Vagts A., Vandlen R.L., Watanabe C., Wieand D., Woods K., Xie M.-H., Yansura D.G., Yi S., Yu G., Yuan J., Zhang M., Zhang Z., Goddard A.D., Wood W.I., Godowski P.J., Gray A.M. Genome Res. 13:2265-2270(2003) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] (ISOFORM A1).
[3]	Mural R.J., Istrail S., Sutton G.G., Florea L., Halpern A.L., Mobarry C.M., Lippert R., Walenz B., Shatkay H., Dew I., Miller J.R., Flanigan M.J., Edwards N.J., Bolanos R., Fasulo D., Halldorsson B.V., Hannenhalli S., Turner R. , Yooseph S., Lu F., Nusskern D.R., Shue B.C., Zheng X.H., Zhong F., Delcher A.L., Huson D.H., Kravitz S.A., Mouchard L., Reinert K., Remington K.A., Clark A.G., Waterman M.S., Eichler E.E., Adams M.D., Hunkapiller M.W., Myers E.W., Venter J.C. Submitted (SEP-2005) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
[4]	"The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC)." The MGC Project Team Genome Res. 14:2121-2127(2004) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] (ISOFORM A1).
+	Additional computationally mapped references.

Cross-references

Sequence databases
EMBL GenBank DDBJ	AF221069 mRNA. Translation: AAF26448.1. AF349452 mRNA. Translation: AAL15637.1. AY358479 mRNA. Translation: AAQ88843.1. CH471052 Genomic DNA. Translation: EAW79092.1. BC142708 mRNA. Translation: AAI42709.1. BC146668 mRNA. Translation: AAI46669.1.
IPI	IPI00011601. IPI00218314.
RefSeq	NP_001002026.1. NM_001002026.2. NP_057453.1. NM_016369.3.
UniGene	Hs.655324.
3D structure databases
ProteinModelPortal	P56856.
ModBase	Search...
Protein-protein interaction databases
DIP	DIP-48955N.
STRING	9606.ENSP00000183605.
PTM databases
PhosphoSite	P56856.
Polymorphism databases
DMDM	7387578.
Proteomic databases
PaxDb	P56856.
PRIDE	P56856.
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Genome annotation databases
Ensembl	ENST00000183605; ENSP00000183605; ENSG00000066405. ENST00000343735; ENSP00000340939; ENSG00000066405.
GeneID	51208.
KEGG	hsa:51208.
UCSC	uc003ero.1. human. uc003erp.1. human.
Organism-specific databases
CTD	51208.
GeneCards	GC03P137717.
H-InvDB	HIX0003711.
HGNC	HGNC:2039. CLDN18.
HPA	CAB013010. CAB013243.
MIM	609210. gene.
neXtProt	NX_P56856.
PharmGKB	PA26565.
GenAtlas	Search...
Phylogenomic databases
eggNOG	NOG46146.
HOGENOM	HOG000220937.
HOVERGEN	HBG102991.
KO	K06087.
OMA	CIRIGNM.
Enzyme and pathway databases
Reactome	REACT_111155. Cell-Cell communication.
Gene expression databases
ArrayExpress	P56856.
Bgee	P56856.
CleanEx	HS_CLDN18.
Genevestigator	P56856.
GermOnline	ENSG00000066405. Homo sapiens.
Family and domain databases
InterPro	IPR006187. Claudin. IPR003928. Claudin18. IPR017974. Claudin_CS. IPR004031. PMP22/EMP/MP20/Claudin. [Graphical view]
PANTHER	PTHR12002. PTHR12002. 1 hit. PTHR12002:SF9. PTHR12002:SF9. 1 hit.
Pfam	PF00822. PMP22_Claudin. 1 hit. [Graphical view]
PRINTS	PR01077. CLAUDIN. PR01448. CLAUDIN18.
PROSITE	PS01346. CLAUDIN. 1 hit. [Graphical view]
ProtoNet	Search...
Other
GenomeRNAi	51208.
NextBio	54274.
SOURCE	Search...

Entry information

Entry name

CLD18_HUMAN

Accession

Primary (citable) accession number: P56856
Secondary accession number(s): A5PL21, Q96PH4

Entry history

Integrated into UniProtKB/Swiss-Prot:	May 30, 2000
Last sequence update:	May 30, 2000
Last modified:	April 3, 2013
This is version 108 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Chordata Protein Annotation Program

Disclaimer

Any medical or genetic information present in this entry is provided for research, educational and informational purposes only. It is not in any way intended to be used as a substitute for professional medical advice, diagnosis, treatment or care.