Tight junction-associated protein 1 (also known as Pilt) is a family of eukaryotic tight junction-proteins []. Pilt is a component of TJs (Tight junctions) rather than AJs (Adhesin junctions). TJs function as a barrier preventing solutes and water from passing freely through the paracellular pathway. TJs consist of transmembrane proteins (claudin, occludin, and JAM) plus many peripheral membrane proteins and cell polarity molecules. Pilt is a novel peripheral membrane protein which is incorporated into TJs after TJ strands are formed, thereby the name Pilt for 'protein incorporated later into TJs'. Pilt binds to the guanylate-kinase region of hDlg/SAP97 (disk large homologue/synapse-associated protein 97) [].
