Crumbs cell polarity complex component 3 (CRB3)

Crumbs cell polarity complex component 3 (CRB3) is a highly conserved, small transmembrane protein predominantly expressed in mammalian epithelial tissues, where it localizes to the apical membrane and is a core member of the Crumbs apical polarity complex[1][2][3]. CRB3 interacts with scaffolding proteins such as PALS1 and PATJ to form the Crumbs complex, which is essential for establishing and maintaining apical-basal polarity in epithelial cells and regulating the structure and function of tight junctions[1][2][3]. Through its cytoplasmic tail, CRB3 binds directly to partners like Par6 and is involved in regulating actin dynamics, tissue morphogenesis, and the Hippo/YAP pathway, influencing cell proliferation and organ size[1][2][3]. While not traditionally classified as a direct therapeutic target such as receptors, enzymes, or transporters, CRB3 has been implicated in cancer biology, acting as a putative tumor suppressor and modulating cell polarity loss associated with cancer progression[4]. Knockout or dysfunction of CRB3 can result in developmental defects and altered epithelial tissue organization, with studies in knockout mice indicating abnormalities in lung development[1]. **Notes:** - CRB3 is not a classic therapeutic target like a receptor or enzyme, and no drugs are currently known to directly target or modulate its activity[1][2][3][4]. - There are no established biomarkers or safety concerns specifically associated with CRB3 modulation. - Its main biological importance lies in fundamental epithelial tissue organization and the regulation of cell polarity rather than as a druggable target.

Other names

Protein crumbs homolog 3UNQ588/PRO1158MGC17303crumbs 3cell polarity complex componentcrumbs family member 3CRB3