Members of the claudin protein family, such as CLDN2, are expressed in an organ-specific manner and regulate the tissue-specific physiologic properties of tight junctions (Sakaguchi et al., 2002).

[supplied by OMIM][6] Claudin-2 is expressed in cation-leaky epithelia such as that of the kidney proximal tubule.

[7] Mice that are deficient in claudin-2 have reduced reabsorption of Na+ in the proximal tubule, consistent with a role in paracellular transport.

Similar results have been obtained with cultured cells, as overexpression in claudin-2 lacking cells leads to increase of permeability for small cations.

This article on a gene on the human X chromosome and/or its associated protein is a stub.