Tight Junction Protein 1 (TJP1)

Tight junction protein ZO-1 is a protein located on a cytoplasmic membrane surface of intercellular tight junctions. The encoded protein may be involved in signal transduction at cell-cell junctions. Two transcript variants encoding distinct isoforms have been identified for this gene. Tight junction (zonula occludens) protein-1 (TJP1), also referred to as ZO-1, is a 200-kD protein located on a cytoplasmic membrane surface of vertebrate intercellular tight junctions. Willott et al. (1993) isolated a full-length cDNA sequence for human TJP1. Although the function of TJP1 is unknown, the cDNA sequence predicted a multi-domain signaling protein homologous to the product of the 'discs large-1' tumor suppressor gene of Drosophila  and several other membrane-associated proteins in mammals.