Involved in hearing and vision as member of the USH2 complex. Necessary for elongation and maintenance of inner and outer hair cell stereocilia in the organ of Corti in the inner ear. Involved in the maintenance of the hair bundle ankle region, which connects stereocilia in cochlear hair cells of the inner ear. In retina photoreceptors, required for the maintenance of periciliary membrane complex that seems to play a role in regulating intracellular protein transport. Forms homooligomers (By similarity). Interacts (via C-terminal PDZ domain) with MYO15A; this interaction is necessary for localization of WHRN to stereocilia tips. Interacts (via C-terminal PDZ domain) with MPP1/p55. Interacts with LRRC4C/NGL1. Interacts with MYO7A. Interacts with RPGR. Interacts with EPS8 (By similarity). Interacts with CASK (PubMed:12641734). Interacts with CIB2 (By similarity). Component of USH2 complex, composed of ADGRV1, PDZD7, USH2A and WHRN. Interacts (via PDZ domains) with PDZD7; the interaction is direct. Interacts (via N-terminal PDZ domain) with USH2A (via cytoplasmic region). Interacts with ADGRV1/MASS1 (via cytoplasmic region) (By similarity). Detected at the level of stereocilia in inner outer hair cells of the cochlea and vestibule (PubMed:16434480). Localizes to both tip and ankle-link stereocilia regions (PubMed:23055499). Colocalizes with the growing ends of actin filaments (By similarity). Colocalizes with MPP1 in the retina, at the outer limiting membrane (OLM), outer plexifirm layer (OPL), basal bodies and at the connecting cilium (CC) (PubMed:16434480, PubMed:17584769). In photoreceptors, localizes at a plasma membrane microdomain in the apical inner segment that surrounds the connecting cilia called periciliary membrane complex (By similarity). Ubiquitous. Highly expressed in heart, spleen, lung and liver. Highly expressed in brain, in the olfactory bulb, thalamus, layers III-V of the cerebral cortex and the molecular layer of cerebellum. Detected in soma and dendrites of thalamic neurons, and in cerebrum in cell bodies and apical dendrites of pyramidal neurons. Expressed in retina and inner ear (PubMed:16434480, PubMed:23055499).