Potential calcium-dependent cell-adhesion protein. May be required for the structural integrity of the outer segment (OS) of photoreceptor cells. Interacts with PROM1. Localized at the junction between the inner and outer segments of rod and cone photoreceptors cells. Confined to the base of the OS. Localized on the edges of nascent evaginating disks on the side of the OS opposite the connecting cilium. Expressed at postnatal day 2 at the apical tip of the rod photoreceptor cells, the site of the developing OS. Colocalized with rhodopsin between postnatal days 2 and 9 at the base of the growing OS region. Expressed in cone and rod photoreceptor cells (at protein level). Expressed in photoreceptor cells of the outer nuclear layer of the retina. Expressed in mitral and tufted cells in the olfactory bulb. Undergoes proteolytic cleavage; produces a soluble 95 kDa N-terminal fragment and a 25 kDa cell-associated C-terminal fragment. Mice have no obvious phenotype but show photoreceptor cell death as early as 1 month of age shortly after completion of retinal development. Its absence severely compromises the structure of OS which are disorganized and fragmented, but the consequences on photoreceptor electrical signaling are very mild. Proteolytic cleavage is partially inhibited in the absence of orderly OS assembly in mouse retinas lacking RDS/peripherin. Partially unspliced pre-RNA.