Claudin-1
Organism: Homo sapiens (Human) | Gene names: CLDN1, CLD1, SEMP1, UNQ481/PRO944
Entry: O95832
Mass: 22.744 Da
Transmembrane: 4
Subcellular location: Cell junction, tight junction {ECO:0000269|PubMed:20375010, ECO:0000269|PubMed:23407391}. Cell membrane {ECO:0000269|PubMed:23704991}, Multi-pass membrane protein {ECO:0000255}. Basolateral cell membrane {ECO:0000269|PubMed:20375010}. Note=Associates with CD81 and the CLDN1-CD81 complex localizes to the basolateral cell membrane. {ECO:0000269|PubMed:20375010}.
Cofactor: -
Extinction coefficient: 1.821
Isoelectric Point: 8.41
PubMed ID: 9931503, 10828592, 11071387, 12975309, 15489334, 15521008, 16619213, 17325668, 20375010, 21269460, 21516087, 23407391, 24074594, 23704991, 24038151
Family: Claudin family
Function:
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). {ECO:0000269|PubMed:23407391}.; (Microbial infection) Acts as a co-receptor for hepatitis C virus (HCV) in hepatocytes (PubMed:17325668, PubMed:20375010, PubMed:24038151). 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). {ECO:0000269|PubMed:17325668, ECO:0000269|PubMed:20375010, ECO:0000269|PubMed:24038151, ECO:0000269|PubMed:24074594}.
Data from experiment(s):
Involvement in disease:
Ichthyosis-sclerosing cholangitis neonatal syndrome (NISCH) [MIM:607626]: A rare autosomal recessive complex ichthyosis syndrome characterized by scalp hypotrichosis, scarring alopecia, mild diffuse ichthyosis, sclerosing cholangitis and leukocyte vacuolization. {ECO:0000269|PubMed:15521008, ECO:0000269|PubMed:16619213}. Note=The disease is caused by variants affecting the gene represented in this entry.
Binding site:
-
Tissue specificity:
Strongly expressed in liver and kidney. Expressed in heart, brain, spleen, lung and testis. {ECO:0000269|PubMed:9931503}.
3D (X-ray crystallography):
-
Pharmaceutical use:
-
AS sequence:
MANAGLQLLGFILAFLGWIGAIVSTALPQWRIYSYAGDNIVTAQAMYEGLWMSCVSQSTGQIQCKVFDSLLNLSSTLQATRALMVVGILLGVIAIFVATVGMKCMKCLEDDEVQKMRMAVIGGAIFLLAGLAILVATAWYGNRIVQEFYDPMTPVNARYEFGQALFTGWAAASLCLLGGALLCCSCPRKTTSYPTPRPYPKPAPSSGKDYV
Creditnotes:
The protein visualizations are generated with the help of Protter:
Omasits, U., Ahrens, C.H., Müller, S., Wollscheid, B. “Protter: interactive protein feature visualization and integration with experimental proteomic data”. Bioinformatics. 2014 Mar 15; 30(6):884-6. doi: 10.1093/bioinformatics/btt607.
IP and extinction coefficients are gathered from Protparam by ExPASy:
Gasteiger, E., Hoogland, C., Gattiker, A., Duvaud, S., Wilkins, M.R., Appel, R.D., Bairoch, A. “Protein Identification and Analysis Tools on the ExPASy Server”. (In) John M. Walker (ed): The Proteomics Protocols Handbook, Humana Press (2005). pp. 571-607
The basic knowledge is found on UniProt:
The UniProt Consortium. “UniProt: the universal protein knowledgebase in 2021”. Nucleic Acids Res. 49:D1 (2021)
Omasits, U., Ahrens, C.H., Müller, S., Wollscheid, B. “Protter: interactive protein feature visualization and integration with experimental proteomic data”. Bioinformatics. 2014 Mar 15; 30(6):884-6. doi: 10.1093/bioinformatics/btt607.
IP and extinction coefficients are gathered from Protparam by ExPASy:
Gasteiger, E., Hoogland, C., Gattiker, A., Duvaud, S., Wilkins, M.R., Appel, R.D., Bairoch, A. “Protein Identification and Analysis Tools on the ExPASy Server”. (In) John M. Walker (ed): The Proteomics Protocols Handbook, Humana Press (2005). pp. 571-607
The basic knowledge is found on UniProt:
The UniProt Consortium. “UniProt: the universal protein knowledgebase in 2021”. Nucleic Acids Res. 49:D1 (2021)