Anti-CRB3A Antibody, clone 1E6 clone 1E6, from rat

Protein crumbs homolog 3 (UniProt: Q9BUF7) is encoded by the CRB3 (also known as UNQ588/PRO1158) gene (Gene ID: 92359) in human. Mammalian cells contain three Crb orthologs. CRB1 is primarily expressed in the brain, cornea, and retina. CRB2 is expressed in lung, kidney, retina, colon and mammary glands. It is also expressed in at moderate levels in Expressed at moderate levels in liver, spleen, pancreas, placenta, and prostate tissue. CRB3 is present in epithelial tissues and is present in two isoforms, CRB3A and CRB3B. CRB3 is a single-pass type I membrane protein that is reported to control epithelial cell polarization. CRB3A is apically localized and promotes apical membrane growth and is and is essential for the formation of tight junctions in epithelial cells. It also prevents the epithelial-to-mesenchymal transition (EMT), which is known to contribute to tumor progression. CRB3 is synthesized with a signal peptide (aa 1-26), which is subsequently cleaved off. The mature form contains an extracellular domain (aa 27-59), a transmembrane domain (aa 60-80), and a cytoplasmic tail (aa 81-120), which contains a PDZ-domain binding motif (aa 117-120) that interacts with the Maguk protein, PALS1, which recruits PALS1-associated tight junction (PATJ) protein into the CRB3A complex. Both PALS1 and PATJ play a critical role in epithelial cell polarity and tight junction formation. CRB3A is shown to control and properly localize RhoA signaling that is required for CRB3A-dependent reorganization of the actin cytoskeleton. (Ref.: Loie, E., et al (2015). Mol. Cell Biol. 35(19); 3423-3435).