Anti-Zonula occludens protein 3/TJP3 Antibody Picoband®

TJP3 (TIGHT JUNCTION PROTEIN 3), also called ZO3, is a protein that in humans is encoded by the TJP3 gene. TJP3 is a member of the family of membrane-associated guanylate kinase-like proteins (MAGUK) that associate with intracellular junctions (Itoh et al., 1999) . Haskins et al. (1998) showed that recombinant Tjp3 binds in vitro translated Tjp1 and binds ly to the cytoplasmic tail of occludin but no binding was detected between Tjp3 and Tjp2. Roh et al. (2002) determined that Tjp3 interacted with PATJ (INADL) and that both proteins colocalized to tight junctions in vivo. In vitro studies showed that the sixth and eighth PDZ domains of PATJ mediated interaction with the Tjp3 C-terminal domain and with Cldn1, respectively.

Type I isoforms are the predominant forms expressed in the endocardium. Isoform alpha is expressed in breast, ovary, testis, prostate, heart, skeletal muscle, lung, placenta liver, kidney, salivary gland, small intestine and brain, but not in uterus, stomach, pancreas, and spleen. Isoform 3 is the predominant form in mesenchymal cells and in non-neuronal organs, whereas isoform 6 is the major neuronal form. Isoform 8 is expressed in spinal cord and brain. Isoform 9 is the major form in skeletal muscle cells; in the nervous system it is expressed in spinal cord and brain. Also detected in adult heart, placenta, lung, liver, kidney, and pancreas. Isoform 10 is expressed in nervous system: spinal cord motor neurons, dorsal root ganglion neurons, and brain. Predominant isoform expressed in sensory and motor neurons. Not detected in adult heart, placenta, lung, liver, skeletal muscle, kidney, and pancreas. Not expressed in fetal lung, liver and kidney. Type IV isoforms are brain-specific. .

1. Haskins, J., Gu, L., Wittchen, E. S., Hibbard, J., Stevenson, B. R. ZO-3, a novel member of the MAGUK protein family found at the tight junction, interacts with ZO-1 and occludin. J. Cell Biol. 141: 199-208, 1998. 2. Itoh, M., Furuse, M., Morita, K., Kubota, K., Saitou, M., Tsukita, S. binding of three tight junction-associated MAGUKs, ZO-1, ZO-2, and ZO-3, with the COOH termini of claudins. J. Cell Biol. 147: 1351-1363, 1999. 3. Roh, M. H., Liu, C.-J., Laurinec, S., Margolis, B. The carboxyl terminus of zona occludens-3 binds and recruits a mammalian homologue of discs lost to tight junctions. J. Biol. Chem. 277: 27501-27509, 2002.

Store at -20°C for one year from date of receipt. After reconstitution, at 4°C for one month. It can also be aliquotted and stored frozen at -20°C for six months. Avoid repeated freeze-thaw cycles.