Plays a role in photoreceptor morphogenesis in the retina (By similarity). May maintain cell polarization and adhesion (By similarity). Component of a complex composed of PALS1, CRB1 and EPB41L5 (PubMed:17920587). Within the complex, interacts (via intracellular domain) with PALS1 and EPB41L5 (via FERM domain) (PubMed:17920587). Forms a complex with MPP4 and PALS1 (PubMed:15914641). Interacts with MPDZ/MUPP1 and MPP4 (By similarity). Preferential expression in retina, also expressed in brain, testis, fetal brain and fetal eye (PubMed:15914641). Expressed at the outer limiting membrane and apical to adherens junctions in the retina (PubMed:15914641). Expressed in the retinal layer of the optic vesicle, and weakly expressed in the retinal pigment epithelium at 12.5 dpc. Extensively glycosylated. CRB1 mutations have been found in various retinal dystrophies, chronic and disabling disorders of visual function. They predominantly involve the posterior portion of the ocular fundus, due to degeneration in the sensory layer of the retina, retinal pigment epithelium, Bruch membrane, choroid, or a combination of these tissues. Onset of inherited retinal dystrophies is painless, bilateral and typically progressive. Most people experience gradual peripheral vision loss or tunnel vision, and difficulties with poor illumination and night vision. Central vision is usually unaffected, so the person may still be able to read. However, it can also deteriorate to cause total blindness. Examples of retinal dystrophies are retinitis pigmentosa, Leber congenital amaurosis, cone-rod dystrophy among others. The disease is caused by variants affecting the gene represented in this entry. The disease is caused by variants affecting the gene represented in this entry. The disease is caused by variants affecting the gene represented in this entry. Belongs to the Crumbs protein family. Truncated C-terminus. Retina International's Scientific Newsletter