Tight Junction Protein 2 (TJP2)

TJP2 encodes a zonula occluden that is a member of the membrane-associated guanylate kinase homolog family. The encoded protein functions as a component of the tight junction barrier in epithelial and endothelial cells and is necessary for proper assembly of tight junctions. Mutation in this gene have been identified in patients with hypercholanemia. Alternate splicing results in multiple transcript variants. This protein is found in epithelial cell junctions. Isoform A1 is abundant in the heart and brain whereas isoform C1 is expressed at high level in the kidney, pancreas, heart and placenta. In brain and skeletal muscle, only isoform A1 is detectable. Isoform C1 is found in normal as well as in most neoplastic tissues while isoform A1 is present almost exclusively in normal tissue.