CLDN1

Functionⁱ

Claudins function as major constituents of the tight junction complexes that regulate the permeability of epithelia. While some claudin family members play essential roles in the formation of impermeable barriers, others mediate the permeability to ions and small molecules. Often, several claudin family members are coexpressed and interact with each other, and this determines the overall permeability. CLDN1 is required to prevent the paracellular diffusion of small molecules through tight junctions in the epidermis and is required for the normal barrier function of the skin. Required for normal water homeostasis and to prevent excessive water loss through the skin, probably via an indirect effect on the expression levels of other proteins, since CLDN1 itself seems to be dispensable for water barrier formation in keratinocyte tight junctions (PubMed:23407391).1 Publication

(Microbial infection) Acts as a receptor for hepatitis C virus (HCV) in hepatocytes (PubMed:17325668, PubMed:20375010). Associates with CD81 and the CLDN1-CD81 receptor complex is essential for HCV entry into host cell (PubMed:20375010). Acts as a receptor for dengue virus (PubMed:24074594).3 Publications

GO - Molecular functionⁱ

identical protein binding Source: UniProtKB
structural molecule activity Source: InterPro
virus receptor activity
Source: UniProtKB
Inferred from mutant phenotypeⁱ
- 20375010

View the complete GO annotation on QuickGO ...

GO - Biological processⁱ

aging Source: Ensembl
bicellular tight junction assembly
Source: UniProtKB
Inferred from mutant phenotypeⁱ
- 25849148
calcium-independent cell-cell adhesion via plasma membrane cell-adhesion molecules Source: UniProtKB
cell-cell junction organization
Source: MGI
Inferred from mutant phenotypeⁱ
- 20164257
cellular response to butyrate Source: Ensembl
cellular response to interferon-gamma Source: Ensembl
cellular response to lead ion Source: Ensembl
cellular response to transforming growth factor beta stimulus Source: Ensembl
cellular response to tumor necrosis factor Source: Ensembl
drug transport across blood-nerve barrier Source: Ensembl
establishment of blood-nerve barrier Source: Ensembl
establishment of endothelial intestinal barrier Source: Ensembl
establishment of skin barrier
Source: UniProtKB
Inferred from mutant phenotypeⁱ
- 23407391
hyperosmotic salinity response Source: Ensembl
liver regeneration Source: Ensembl
positive regulation of bicellular tight junction assembly Source: Ensembl
protein heterooligomerization
Source: UniProtKB
Inferred from genetic interactionⁱ
- 25849148
protein homooligomerization
Source: UniProtKB
Inferred from mutant phenotypeⁱ
- 25849148
response to dexamethasone Source: Ensembl
response to ethanol Source: Ensembl
response to interleukin-18 Source: Ensembl
response to lipopolysaccharide Source: Ensembl

View the complete GO annotation on QuickGO ...

Keywordsⁱ

Molecular function	Host cell receptor for virus entry, Receptor
Biological process	Host-virus interaction

Enzyme and pathway databases

Reactomeⁱ	R-HSA-420029 Tight junction interactions

Reactomeⁱ

R-HSA-420029 Tight junction interactions

Protein family/group databases

TCDBⁱ	1.H.1.1.14 the claudin tight junction (claudin1) family

TCDBⁱ

1.H.1.1.14 the claudin tight junction (claudin1) family

Names & Taxonomyⁱ

Protein namesⁱ	Recommended name: Claudin-1 Alternative name(s): Senescence-associated epithelial membrane protein
Gene namesⁱ	Name:CLDN1 Synonyms:CLD1, SEMP1 ORF Names:UNQ481/PRO944
Organismⁱ	Homo sapiens (Human)
Taxonomic identifierⁱ	9606 [NCBI]
Taxonomic lineageⁱ	cellular organisms › Eukaryota › Opisthokonta › Metazoa › Eumetazoa › Bilateria › Deuterostomia › Chordata › Craniata › Vertebrata › Gnathostomata › Teleostomi › Euteleostomi › Sarcopterygii › Dipnotetrapodomorpha › Tetrapoda › Amniota › Mammalia › Theria › Eutheria › Boreoeutheria › Euarchontoglires › Primates › Haplorrhini › Simiiformes › Catarrhini › Hominoidea › Hominidae › Homininae › Homo
Proteomesⁱ	UP000005640 Componentⁱ: Chromosome 3

Organism-specific databases

EuPathDBⁱ	HostDB:ENSG00000163347.5
Human Gene Nomenclature Database More...HGNCⁱ	HGNC:2032 CLDN1
MIMⁱ	603718 gene
neXtProtⁱ	NX_O95832

Topology

Feature key	Position(s)	DescriptionActions	Length
Topological domainⁱ	1 – 7	CytoplasmicBy similarity	7
Transmembraneⁱ	8 – 28	HelicalSequence analysisAdd BLAST	21
Topological domainⁱ	29 – 81	ExtracellularSequence analysisAdd BLAST	53
Transmembraneⁱ	82 – 102	HelicalSequence analysisAdd BLAST	21
Topological domainⁱ	103 – 115	CytoplasmicSequence analysisAdd BLAST	13
Transmembraneⁱ	116 – 136	HelicalSequence analysisAdd BLAST	21
Topological domainⁱ	137 – 163	ExtracellularSequence analysisAdd BLAST	27
Transmembraneⁱ	164 – 184	HelicalSequence analysisAdd BLAST	21
Topological domainⁱ	185 – 211	CytoplasmicBy similarityAdd BLAST	27

Keywords - Cellular componentⁱ

Cell junction, Cell membrane, Membrane, Tight junction

Pathology & Biotechⁱ

Involvement in diseaseⁱ

Ichthyosis-sclerosing cholangitis neonatal syndrome (NISCH)2 Publications

The disease is caused by mutations affecting the gene represented in this entry.

Disease descriptionA rare autosomal recessive complex ichthyosis syndrome characterized by scalp hypotrichosis, scarring alopecia, mild diffuse ichthyosis, sclerosing cholangitis and leukocyte vacuolization.

Mutagenesis

Feature key	Position(s)	DescriptionActions	Graphical view	Length
Mutagenesisⁱ	32	I → M: Loss of HCV receptor activity. Significant loss of interaction with CD81. Reduced interaction with OCLN. 2 Publications		1
Mutagenesisⁱ	48	E → K: Loss of HCV receptor activity. Significant loss of interaction with CD81. Reduced interaction with OCLN. According to PubMed:17325668 no effect observed on HCV infection susceptibility in cell culture. 2 Publications		1

Keywords - Diseaseⁱ

Ichthyosis

Organism-specific databases

DisGeNET More...DisGeNETⁱ	9076
MalaCards human disease database More...MalaCardsⁱ	CLDN1
MIMⁱ	607626 phenotype
Open Targets More...OpenTargetsⁱ	ENSG00000163347
Orphanetⁱ	59303 Neonatal ichthyosis-sclerosing cholangitis syndrome
PharmGKBⁱ	PA26557

Polymorphism and mutation databases

BioMutaⁱ	CLDN1

BioMutaⁱ

CLDN1

PTM / Processingⁱ

Molecule processing

Feature key	Position(s)	DescriptionActions	Graphical view	Length
ChainⁱPRO_0000144729	1 – 211	Claudin-1Add BLAST		211

Amino acid modifications

Feature key	Position(s)	DescriptionActions	Graphical view	Length
Disulfide bondⁱ	54 ↔ 64	By similarity

Keywords - PTMⁱ

Disulfide bond

Proteomic databases

EPDⁱ	O95832
MaxQB - The MaxQuant DataBase More...MaxQBⁱ	O95832
PaxDbⁱ	O95832
PeptideAtlas More...PeptideAtlasⁱ	O95832
PRIDEⁱ	O95832
ProteomicsDBⁱ	51077

PTM databases

iPTMnetⁱ	O95832
PhosphoSitePlusⁱ	O95832
SwissPalmⁱ	O95832

Expressionⁱ

Tissue specificityⁱ

Strongly expressed in liver and kidney. Expressed in heart, brain, spleen, lung and testis.1 Publication

Gene expression databases

Bgeeⁱ	ENSG00000163347 Expressed in 158 organ(s), highest expression level in skin of abdomen
CleanExⁱ	HS_CLDN1
ExpressionAtlasⁱ	O95832 baseline and differential
Genevisibleⁱ	O95832 HS

Organism-specific databases

Human Protein Atlas More...HPAⁱ	CAB002602 HPA048319

HPAⁱ

CAB002602
HPA048319

Interactionⁱ

Subunit structureⁱ

Homopolymers interact with CLDN3, but not CLDN2, homopolymers. Can form homo- and heteropolymers with other claudin family members (PubMed:23704991). Directly interacts with TJP1/ZO-1, TJP2/ZO-2 and TJP3/ZO-3. Interacts with MPDZ and PATJ (By similarity). Interacts with OCLN, CLDN4, CLDN6 and CLDN9 (PubMed:20375010). Interacts with CD81 (PubMed:20375010, PubMed:21516087).By similarity3 Publications

(Microbial infection) Interacts with hepatitis c virus E1 and E2 proteins.1 Publication

(Microbial infection) Interacts with dengue virus small envelope protein M.1 Publication

Binary interactionsⁱ

With	Entry	#Exp.	IntAct	Notes
TACSTD2	P09758	2	EBI-723889,EBI-4324738

With

Entry

#Exp.

IntAct

Notes

TACSTD2

P09758

2

EBI-723889,EBI-4324738

GO - Molecular functionⁱ

identical protein binding Source: UniProtKB

View the complete GO annotation on QuickGO ...

Protein-protein interaction databases

BioGridⁱ	114533, 7 interactors
CORUMⁱ	O95832
IntActⁱ	O95832, 10 interactors
Molecular INTeraction database More...MINTⁱ	O95832
STRINGⁱ	9606.ENSP00000295522

Structureⁱ

3D structure databases

ProteinModelPortalⁱ	O95832
ModBaseⁱ	Search...
MobiDBⁱ	Search...

Family & Domainsⁱ

Region

Feature key	Position(s)	DescriptionActions	Graphical view	Length
Regionⁱ	210 – 211	Interactions with TJP1, TJP2, TJP3 and PATJBy similarity		2

Sequence similaritiesⁱ

Belongs to the claudin family.Curated

Keywords - Domainⁱ

Transmembrane, Transmembrane helix

Phylogenomic databases

eggNOGⁱ	ENOG410IG63 Eukaryota ENOG4111GMP LUCA
Ensembl GeneTree More...GeneTreeⁱ	ENSGT00760000118928
HOGENOMⁱ	HOG000220937
HOVERGENⁱ	HBG000643
InParanoidⁱ	O95832
KEGG Orthology (KO) More...KOⁱ	K06087
OMAⁱ	WKIYSYA
Database of Orthologous Groups More...OrthoDBⁱ	EOG091G0MX2
PhylomeDBⁱ	O95832
TreeFamⁱ	TF331936

Family and domain databases

InterProⁱ	View protein in InterPro IPR006187 Claudin IPR003548 Claudin1 IPR017974 Claudin_CS IPR004031 PMP22/EMP/MP20/Claudin
PANTHERⁱ	PTHR12002 PTHR12002, 1 hit PTHR12002:SF92 PTHR12002:SF92, 1 hit
Pfam protein domain database More...Pfamⁱ	View protein in Pfam PF00822 PMP22_Claudin, 1 hit
PRINTSⁱ	PR01377 CLAUDIN1
PROSITEⁱ	View protein in PROSITE PS01346 CLAUDIN, 1 hit

Sequenceⁱ

Sequence statusⁱ: Complete.

O95832-1 [UniParc]FASTA Add to basket

« Hide

        10         20         30         40         50
MANAGLQLLG FILAFLGWIG AIVSTALPQW RIYSYAGDNI VTAQAMYEGL 
        60         70         80         90        100
WMSCVSQSTG QIQCKVFDSL LNLSSTLQAT RALMVVGILL GVIAIFVATV 
       110        120        130        140        150
GMKCMKCLED DEVQKMRMAV IGGAIFLLAG LAILVATAWY GNRIVQEFYD 
       160        170        180        190        200
PMTPVNARYE FGQALFTGWA AASLCLLGGA LLCCSCPRKT TSYPTPRPYP 
       210 
KPAPSSGKDY V

Length:211

Mass (Da):22,744

Last modified:May 1, 1999 - v1

Checksum:ⁱ07269000E6C214F0

GO

Experimental Info

Feature key	Position(s)	DescriptionActions	Graphical view	Length
Sequence conflictⁱ	62	I → V in AAD22962 (Ref. 2) Curated		1
Sequence conflictⁱ	135	V → A in AAD22962 (Ref. 2) Curated		1

Sequence databases

Select the link destinations: EMBLⁱ GenBankⁱ DDBJⁱ Links Updated	AF101051 mRNA Translation: AAD16433.1 AF115546 mRNA Translation: AAD22962.1 AF134160 mRNA Translation: AAF61393.1 AF260406 , AF260403, AF260404, AF260405 Genomic DNA Translation: AAK20945.1 AY358652 mRNA Translation: AAQ89015.1 CR457138 mRNA Translation: CAG33419.1 BC012471 mRNA Translation: AAH12471.1
The Consensus CDS (CCDS) project More...CCDSⁱ	CCDS3295.1
NCBI Reference Sequences More...RefSeqⁱ	NP_066924.1, NM_021101.4
UniGeneⁱ	Hs.439060

Genome annotation databases

Ensemblⁱ	ENST00000295522; ENSP00000295522; ENSG00000163347
GeneIDⁱ	9076
KEGGⁱ	hsa:9076
UCSC genome browser More...UCSCⁱ	uc003fsh.4 human

Similar proteinsⁱ

100% Identity
90% Identity
50% Identity

Protein	Similar proteins		Species	Score	Length	Source
O95832	Claudin		HUMAN		211	UniRef100_O95832
Claudin		PANTR		211
Claudin		PANPA		211
Claudin		GORGO		211
Claudin		PONAB		59
+5

Protein	Similar proteins		Species	Score	Length	Source
O95832	Claudin-1		BOVIN		211	UniRef90_O95832
Claudin-1		MOUSE		211
Claudin-1		RAT		211
Claudin		HUMAN		211
Claudin		PANTR		211
+100

Protein	Similar proteins		Species	Score	Length	Source
O95832	Claudin-1		RAT		211	UniRef50_O95832
Claudin-1		BOVIN		211
Claudin-1		MOUSE		211
Claudin		HUMAN		211
Claudin		PANTR		211
+124

Cross-referencesⁱ

Sequence databases

Select the link destinations: EMBLⁱ GenBankⁱ DDBJⁱ Links Updated	AF101051 mRNA Translation: AAD16433.1 AF115546 mRNA Translation: AAD22962.1 AF134160 mRNA Translation: AAF61393.1 AF260406 , AF260403, AF260404, AF260405 Genomic DNA Translation: AAK20945.1 AY358652 mRNA Translation: AAQ89015.1 CR457138 mRNA Translation: CAG33419.1 BC012471 mRNA Translation: AAH12471.1
CCDSⁱ	CCDS3295.1
RefSeqⁱ	NP_066924.1, NM_021101.4
UniGeneⁱ	Hs.439060

3D structure databases

ProteinModelPortalⁱ	O95832
ModBaseⁱ	Search...
MobiDBⁱ	Search...

Protein-protein interaction databases

BioGridⁱ	114533, 7 interactors
CORUMⁱ	O95832
IntActⁱ	O95832, 10 interactors
MINTⁱ	O95832
STRINGⁱ	9606.ENSP00000295522

Protein family/group databases

TCDBⁱ	1.H.1.1.14 the claudin tight junction (claudin1) family

TCDBⁱ

1.H.1.1.14 the claudin tight junction (claudin1) family

PTM databases

iPTMnetⁱ	O95832
PhosphoSitePlusⁱ	O95832
SwissPalmⁱ	O95832

Polymorphism and mutation databases

BioMutaⁱ	CLDN1

BioMutaⁱ

CLDN1

Proteomic databases

EPDⁱ	O95832
MaxQBⁱ	O95832
PaxDbⁱ	O95832
PeptideAtlasⁱ	O95832
PRIDEⁱ	O95832
ProteomicsDBⁱ	51077

Protocols and materials databases

The DNASU plasmid repository More...DNASUⁱ	9076
Structural Biology Knowledgebase	Search...

Genome annotation databases

Ensemblⁱ	ENST00000295522; ENSP00000295522; ENSG00000163347
GeneIDⁱ	9076
KEGGⁱ	hsa:9076
UCSCⁱ	uc003fsh.4 human

Organism-specific databases

CTDⁱ	9076
DisGeNETⁱ	9076
EuPathDBⁱ	HostDB:ENSG00000163347.5
GeneCardsⁱ	CLDN1
HGNCⁱ	HGNC:2032 CLDN1
HPAⁱ	CAB002602 HPA048319
MalaCardsⁱ	CLDN1
MIMⁱ	603718 gene 607626 phenotype
neXtProtⁱ	NX_O95832
OpenTargetsⁱ	ENSG00000163347
Orphanetⁱ	59303 Neonatal ichthyosis-sclerosing cholangitis syndrome
PharmGKBⁱ	PA26557
GenAtlas: human gene database More...GenAtlasⁱ	Search...

Phylogenomic databases

eggNOGⁱ	ENOG410IG63 Eukaryota ENOG4111GMP LUCA
GeneTreeⁱ	ENSGT00760000118928
HOGENOMⁱ	HOG000220937
HOVERGENⁱ	HBG000643
InParanoidⁱ	O95832
KOⁱ	K06087
OMAⁱ	WKIYSYA
OrthoDBⁱ	EOG091G0MX2
PhylomeDBⁱ	O95832
TreeFamⁱ	TF331936

Enzyme and pathway databases

Reactomeⁱ	R-HSA-420029 Tight junction interactions

Reactomeⁱ

R-HSA-420029 Tight junction interactions

Miscellaneous databases

ChiTaRSⁱ	CLDN1 human
GeneWikiⁱ	CLDN1
GenomeRNAiⁱ	9076
Protein Ontology More...PROⁱ	PR:O95832
SOURCEⁱ	Search...

Gene expression databases

Bgeeⁱ	ENSG00000163347 Expressed in 158 organ(s), highest expression level in skin of abdomen
CleanExⁱ	HS_CLDN1
ExpressionAtlasⁱ	O95832 baseline and differential
Genevisibleⁱ	O95832 HS

Family and domain databases

InterProⁱ	View protein in InterPro IPR006187 Claudin IPR003548 Claudin1 IPR017974 Claudin_CS IPR004031 PMP22/EMP/MP20/Claudin
PANTHERⁱ	PTHR12002 PTHR12002, 1 hit PTHR12002:SF92 PTHR12002:SF92, 1 hit
Pfamⁱ	View protein in Pfam PF00822 PMP22_Claudin, 1 hit
PRINTSⁱ	PR01377 CLAUDIN1
PROSITEⁱ	View protein in PROSITE PS01346 CLAUDIN, 1 hit
ProtoNetⁱ	Search...

Entry informationⁱ

Entry nameⁱ	CLD1_HUMAN
Accessionⁱ	O95832Primary (citable) accession number: O95832
Entry historyⁱ	Integrated into UniProtKB/Swiss-Prot:	May 30, 2000
	Last sequence update:	May 1, 1999
	Last modified:	November 7, 2018
	This is version 162 of the entry and version 1 of the sequence. See complete history.
Entry statusⁱ	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.

Miscellaneousⁱ

Keywords - Technical termⁱ

Complete proteome, Reference proteome

Documents

SIMILARITY comments
Index of protein domains and families
Human chromosome 3
Human chromosome 3: entries, gene names and cross-references to MIM
MIM cross-references
Online Mendelian Inheritance in Man (MIM) cross-references in UniProtKB/Swiss-Prot

UniProtKB

UniParc

Help

UniRef

Proteomes

Annotation systems

Supporting data

UniProtKB - O95832 (CLD1_HUMAN)

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Claudin-1

Select a section on the left to see content.

<p>This section provides any useful information about the protein, mostly biological knowledge.<p><a href='/help/function_section' target='_top'>More...</a></p>Functioni

<p>The <a href="http://www.geneontology.org/">Gene Ontology (GO)</a> project provides a set of hierarchical controlled vocabulary split into 3 categories:<p><a href='/help/gene_ontology' target='_top'>More...</a></p>GO - Molecular functioni

GO - Biological processi

Enzyme and pathway databases

Protein family/group databases

<p>This section provides information about the protein and gene name(s) and synonym(s) and about the organism that is the source of the protein sequence.<p><a href='/help/names_and_taxonomy_section' target='_top'>More...</a></p>Names & Taxonomyi

Organism-specific databases

<p>This section provides information on the location and the topology of the mature protein in the cell.<p><a href='/help/subcellular_location_section' target='_top'>More...</a></p>Subcellular locationi

Plasma membrane

Other locations

Plasma Membrane

Other locations

Topology

Keywords - Cellular componenti

<p>This section provides information on the disease(s) and phenotype(s) associated with a protein.<p><a href='/help/pathology_and_biotech_section' target='_top'>More...</a></p>Pathology & Biotechi

Mutagenesis

Keywords - Diseasei

Organism-specific databases

Polymorphism and mutation databases

<p>This section describes post-translational modifications (PTMs) and/or processing events.<p><a href='/help/ptm_processing_section' target='_top'>More...</a></p>PTM / Processingi

Molecule processing

Amino acid modifications

Keywords - PTMi

Proteomic databases

PTM databases

<p>This section provides information on the expression of a gene at the mRNA or protein level in cells or in tissues of multicellular organisms.<p><a href='/help/expression_section' target='_top'>More...</a></p>Expressioni

Gene expression databases

Organism-specific databases

<p>This section provides information on the quaternary structure of a protein and on interaction(s) with other proteins or protein complexes.<p><a href='/help/interaction_section' target='_top'>More...</a></p>Interactioni

GO - Molecular functioni

Protein-protein interaction databases

<p>This section provides information on the tertiary and secondary structure of a protein.<p><a href='/help/structure_section' target='_top'>More...</a></p>Structurei

3D structure databases

<p>This section provides information on sequence similarities with other proteins and the domain(s) present in a protein.<p><a href='/help/family_and_domains_section' target='_top'>More...</a></p>Family & Domainsi

Region

<p>This subsection of the ‘Family and domains’ section provides information about the sequence similarity with other proteins.<p><a href='/help/sequence_similarities' target='_top'>More...</a></p>Sequence similaritiesi

Keywords - Domaini

Phylogenomic databases

Family and domain databases

Experimental Info

Sequence databases

Genome annotation databases

<p>This section is used to point to information related to entries and found in data collections other than UniProtKB.<p><a href='/help/cross_references_section' target='_top'>More...</a></p>Cross-referencesi

Sequence databases

3D structure databases

Protein-protein interaction databases

Protein family/group databases

PTM databases

Polymorphism and mutation databases

Proteomic databases

Protocols and materials databases

Genome annotation databases

Organism-specific databases

Phylogenomic databases

Enzyme and pathway databases

Miscellaneous databases

Gene expression databases

Family and domain databases

<p>This section provides general information on the entry.<p><a href='/help/entry_information_section' target='_top'>More...</a></p>Entry informationi

<p>This section contains any relevant information that doesn’t fit in any other defined sections<p><a href='/help/miscellaneous_section' target='_top'>More...</a></p>Miscellaneousi

Keywords - Technical termi

Documents

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Functionⁱ

GO - Molecular functionⁱ

GO - Biological processⁱ

Names & Taxonomyⁱ

Subcellular locationⁱ

Keywords - Cellular componentⁱ

Pathology & Biotechⁱ

Keywords - Diseaseⁱ

PTM / Processingⁱ

Keywords - PTMⁱ

Expressionⁱ

Interactionⁱ

GO - Molecular functionⁱ

Structureⁱ

Family & Domainsⁱ

Sequence similaritiesⁱ

Keywords - Domainⁱ

Cross-referencesⁱ

Entry informationⁱ

Miscellaneousⁱ

Keywords - Technical termⁱ