Involved in hearing and vision as member of the USH2 complex. In the inner ear, required for the maintenance of the hair bundle ankle formation, which connects growing stereocilia in developing cochlear hair cells. In retina photoreceptors, the USH2 complex is required for the maintenance of periciliary membrane complex that seems to play a role in regulating intracellular protein transport.
Subcellular locations: Cell projection, Stereocilium membrane
Component of the interstereocilia ankle links in the inner ear sensory cells. In photoreceptors, localizes at a plasma membrane microdomain in the apical inner segment that surrounds the connecting cilia called periciliary membrane complex.
Subcellular locations: Secreted
Present in the basement membrane of many, but not all tissues. Expressed in retina, cochlea, small and large intestine, pancreas, bladder, prostate, esophagus, trachea, thymus, salivary glands, placenta, ovary, fallopian tube, uterus and testis. Absent in many other tissues such as heart, lung, liver, kidney and brain. In the retina, it is present in the basement membranes in the Bruch's layer choroid capillary basement membranes, where it localizes just beneath the retinal pigment epithelial cells (at protein level). Weakly expressed. Isoform 2 is expressed in fetal eye, cochlea and heart, and at very low level in brain, CNS, intestine, skeleton, tongue, kidney and lung. Isoform 2 is not expressed in stomach and liver. In adult tissues, isoform 2 is expressed in neural retina and testis, and at low level in brain, heart, kidney and liver. Isoform 1 displays a similar pattern of expression but is expressed at very low level in fetal cochlea.