Tight junction protein ZO-1 and Occludin (ZO-1 and Occludin)

Tight junction protein ZO-1 and Occludin are key structural and regulatory components of tight junctions, which form selective barriers between adjacent epithelial or endothelial cells[1][2][5][6]. **ZO-1** is a scaffold protein encoded by the TJP1 gene; it is located on the cytoplasmic side of the cell membrane and organizes tight junctions by connecting transmembrane proteins (like occludin and claudins) to the actin cytoskeleton, thereby maintaining barrier selectivity and epithelial polarity[1][5][6][7]. Its multi-domain structure enables binding to numerous junctional proteins and cytoskeletal elements, playing roles in cytoskeletal organization, signal transduction, and mechanotransduction[2][5]. **Occludin** is a transmembrane protein spanning the membrane four times, with extracellular loops mediating intercellular adhesion and a C-terminal domain that interacts with ZO-1, essential for its trafficking and function at tight junctions[2][6]. Both proteins regulate the permeability of the paracellular pathway and participate in non-canonical functions such as apoptosis regulation, mechanosensing, and gene expression changes. Dysfunction or altered expression of ZO-1 and Occludin is implicated in a variety of diseases involving barrier breakdown, making them informative biomarkers and potential—but challenging—therapeutic targets[2][6][7].

Other names

Zonula occludens-1Tight junction protein 1TJP1OCLN

Enhancement or restoration of tight junction integrity (indirect, via pathway modulation). Reduction of paracellular leak by stabilizing protein-protein or protein-cytoskeleton interactions. Inhibition of protein phosphorylation or disruption of scaffolding complex[4][7].