Claudin 1 [MD376]

Claudin 1 is an essential member of the claudin family, which forms the backbone of tight junctions in epithelial and endothelial cells, regulating paracellular transport. Structurally, claudin 1 spans the membrane with four transmembrane domains and two extracellular loops, which are critical in forming tight junction strands that create selective barriers between cells. This unique structure allows claudin 1 to participate in maintaining cellular polarity and controlling ion permeability, vital functions in organs like the liver and kidney, where claudin 1 is most abundantly expressed. The structural configuration of claudin 1 also facilitates interactions with other tight junction proteins, such as occludins and junctional adhesion molecules, enabling complex tissue compartmentalization. Claudin 1 is a protein that plays a key role in maintaining the integrity and permeability of tight junctions, which are cell-to-cell connections that seal the gaps between epithelial cells.