DefinitionThis section has been translated automatically.
The CLDN1 gene (CLDN1 stands for Claudin 1) is a protein-coding gene located on chromosome 3q28. The protein encoded by this gene, claudin-1, is a member of the claudin family, an integral membrane protein and a component of tight junction strands. Related signaling pathways include cell junction organization and cell adhesion as well as endothelial cell contacts through junctional mechanisms. Loss-of-function mutations lead to neonatal ichthyosis-sclerosing cholangitis syndrome.
Diseases associated with CLDN1 include:
General informationThis section has been translated automatically.
Tight junctions are a form of cell-cell adhesion in epithelial or endothelial cells that form a continuous seal between cell assemblies and act as a physical barrier to prevent solutes and water from flowing freely through the paracellular space.
Claudins act as major components of the tight junction complexes that regulate the permeability of epithelia. While some members of the claudin family play an essential role in the formation of impermeable barriers, others mediate permeability to ions and small molecules. Often several members of the claudin family are co-expressed and interact with each other, which determines the overall permeability.
CLDN1 - Claudin1 is required to prevent paracellular diffusion of small molecules through the tight junctions in the epidermis and is required for normal skin barrier function. The intact protein is required to establish normal water homeostasis and to prevent excessive water loss through the skin. This may occur via an indirect effect by altering the expression levels of other proteins. CLDN1 itself appears to be dispensable for the formation of the water barrier in the tight junctions of keratinocytes.
Microbial infections: CLDN1 acts as a co-receptor for the hepatitis C virus (HCV) in hepatocytes. Associated with CD81, it forms the CLDN1-CD81 receptor complex, which is essential for the entry of HCV into the host cell. Thus, these proteins play an important role in the biology of liver diseases and, in their function as cell entry receptors for HCV, are one of the most common causes of hepatocellular carcinoma (Zeisel MB et al. 2019).
CLDN1 mutations are associated with an increased risk of colorectal cancer (Battagin AS et al.2021).
CLDN1 also acts as a receptor for the dengue virus (Gao F et al. 2010).
LiteratureThis section has been translated automatically.
- Battagin AS et al.(2021) Single nucleotide variants c.-13G → C (rs17429833) and c.108C → T (rs72466472) in the CLDN1 gene and increased risk for familial colorectal cancer. Gene768:145304.
- Gao F et al. (2010) Novel binding between pre-membrane protein and claudin-1 is required for efficient dengue virus entry. Biochem Biophys Res Commun 391:952-957.
- Zeisel MB et al (2019) Tight junction proteins in gastrointestinal and liver disease. Gut 68:547-561
