Cldn1
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.
Sequence Similarities
Belongs to the claudin family.
Tissue Specificity
Detected in epidermis and liver (at protein level). Widely expressed, with highest levels in liver and kidney.
Cellular localization
- Cell junction
- Tight junction
- Cell membrane
- Multi-pass membrane protein
- Basolateral cell membrane
- Associates with CD81 and the CLDN1-CD81 complex localizes to the basolateral cell membrane.
Alternative names
Claudin-1, Cldn1