Crumbs Homolog 3 (CRB3)

CRB3 encodes a member of the Crumbs family of proteins. This protein may play a role in epithelial cell polarity and is associated with tight junctions at the apical surface of epithelial cells. Alternate transcriptional splice variants, encoding different isoforms, have been characterized.

The CRB3 cDNA encodes a deduced 120-amino acid protein with a putative signal peptide in the first 20 amino acids, a putative extracellular N-glycosylation site, and a transmembrane domain. The intracellular domain contains a conserved band-4.1 superfamily-binding site and a Pals PDZ domain-binding site, as found in Drosophila Crumbs and human CRB1.