ZO-1/TJP1 Antibody – Goat Polyclonal

This gene encodes a member of the membrane-associated guanylate kinase (MAGUK) family of proteins, and acts as a tight junction adaptor protein that also regulates adherens junctions. Tight junctions regulate the movement of ions and macromolecules between endothelial and epithelial cells. The multidomain structure of this scaffold protein, including a postsynaptic density 95/disc-large/zona occludens (PDZ) domain, a Src homology (SH3) domain, a guanylate kinase (GuK) domain and unique (U) motifs all help to co-ordinate binding of transmembrane proteins, cytosolic proteins, and F-actin, which are required for tight junction function. Alternative splicing results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Aug 2017]

ZO1: a scaffolding protein of the MAGUK (membrane-associated guanylate kinase) family associated with tight junctions (TJ). May mediate dynamic changes in the composition of TJs. The N-terminal may be involved in transducing a signal required for tight junction assembly, while the C-terminal may have specific properties of tight junctions. The alpha domain might be involved in stabilizing junctions. Plays a role in the regulation of cell migration by targeting the protein kinase MRCKb to the leading edge of migrating cells. Interacts with BVES (via the C-terminus cytoplasmic tail). Interacts with HSPA4 and KIRREL1. Forms homodimers and heterodimers with ZO-2 or ZO-3. Interacts with occludin, CALM, claudins, CGN, CXADR, GJA12, GJD3 and UBN1. Interacts (via ZU5 domain) with MRCKb and MYZAP. Interacts (via PDZ domain) with Cx43. ZO-2 and ZO-3 shuttle between the TJ and the nucleus, where they may regulate gene expression. TJ, or zonula occludens, are the closely associated areas of two cells whose membranes are tightly joined together. They are composed of a branching network of strands, the efficiency of which increases exponentially with the number of strands. The strands associate with transmembrane proteins that bind to similar proteins on adjacent cells, and with submembranous proteins that are anchored to the actin component of the cytoskeleton. Thus, TJs join together the cytoskeletons of adjacent cells. They endow tissues with substantial form, shape and location, enforce cellular polarity, and form barriers to molecules and pathogens. Molecules forming the membranous part of TJs include occludin, claudins, tricellulin and junctional adhesion molecules. These molecules interact with the proteins ZO-1, ZO-2 and ZO-3. Tight junction proteins can be up- or downregulated in cancer and are involved in the epithelial-mesenchymal transitions (EMT) in tumors. Alternative splicing produces two isoforms. The long isoform is found in most epithelial cell junctions. The short isoform is found both in endothelial cells and the highly specialized epithelial junctions of renal glomeruli and Sertoli cells of the seminiferous tubules.

Protein type: Motility/polarity/chemotaxis; Adaptor/scaffold

Chromosomal Location of Human Ortholog: 15q13

Cellular Component: apical junction complex; intercellular canaliculus; tight junction; apicolateral plasma membrane; basolateral plasma membrane; cytosol; cell-cell adherens junction; apical part of cell; cytoplasm; apical plasma membrane; plasma membrane; gap junction; nucleus; cell junction

Molecular Function: protein C-terminus binding; calmodulin binding; protein domain specific binding; protein binding

Biological Process: response to drug; intercellular junction assembly; response to ethanol; sensory perception of sound; apoptosis; negative regulation of vascular permeability; blastocyst formation; response to lipopolysaccharide; cell structure disassembly during apoptosis