Clarin 2 (CLRN2)

CLRN2 belongs to the clarin family of genes. The clarins appear to belong to a large superfamily of small integral membrane glycoproteins with four transmembrane domains. The exact function of this gene is unknown.Clarin1 may be important in development and homeostasis of the inner ear and retina. Mutations within this gene have been associated with Usher syndrome type IIIa. Multiple transcript variants encoding distinct isoforms have been identified for this gene.The USH3A protein has a cytosolic N terminus, 2 helical transmembrane domains, and an endoplasmic reticulum membrane retention signal, TKGH, in the C terminus. Northern blot analysis detected ubiquitous expression of 3 USH3A transcripts of 4.5 kb, 1.4 kb, and 2.0 kb in adult human tissues. RT-PCR analysis detected expression in retina.