Glycoprotein specific to acellular membranes of the inner ear. May be required for the anchoring of the otoconial membranes and cupulae to the underlying neuroepithelia in the vestibule. May be involved in the organization and/or stabilization of the fibrillar network that compose the tectorial membrane in the cochlea. May play a role in mechanotransduction processes. Found in fiber-like structures during the maturation process of the tectorial membrane (PubMed:9405633). Expressed specifically in neuroepithelial supporting cells of the inner ear. Expressed in the cochlea between postnatal day P0 and P6 in pseudostratified cells of the greater epithelial ridge, in supporting cells of the neuroepithelium comprising Deiter's, Hensen's, pillar and Claudius cells, in epithelial cells of the Reissner's membrane, in a small set of cells comprising the spiral prominence. Expressed in the cochlea at P15 in interdental cells located underneath the limbal part of the tectorial membrane. Expressed in the vestibular apparatus at P0 in supporting cells of the saccular, utricular maculae and cristae ampullares, in the epithelial cells of the roof of the saccule but not in the roof of the utricle and cristae ampullares (at protein level). Expressed in the cochlea and vestibular organ of the inner ear. Expressed in the epithelial cells of the otic vesicle at 10 dpc. Expressed in non-sensory cells of the developing vestibule, in the transitory epithelium of the saccule, utricle and cristae ampullares, in epithelial cells of the roof of the saccule, but not the roof of the utricle nor the cristae ampullares at 13 dpc. Expressed in supporting cells of the vestibular maculae at 13 dpc onward birth. Expressed in non-sensory cells of the emerging cochlear duct at 12 dpc. Expressed in the pluristratified sensory epithelium as well as in the epithelium of the roof at 14 dpc. Expressed in the developing sensory epithelium (the spiral limbus, the greater epithelial ridge and the lesser epithelial ridge) of the cochlear duct, the interdental cells of the spiral limbus and in the columnar cells that form the greater epithelial ridge at 16 and 17 dpc. Expressed in the non-sensory pillar, Deiter's and Hensen's cells of the organ of Corti and Claudius cells at 19 dpc onward birth (at protein level). N-glycosylated. Not O-glycosylated. Impaired vestibular and auditory functions. Belongs to the otogelin family.