Otopetrin family

In molecular biology, the otopetrin family is a group of proteins that is restricted to the metazoa. The structure of otopetrin-1 shows it to have 12 transmembrane domains, with three conserved sub-domains (OD-1 to OD-III). Otopetrins modulate calcium homeostasis and influx of calcium in response to extracellular ATP.

The otopetrins are required for normal formation of otoconia/otoliths in the inner ear. Otoconia are minute biomineral particles embedded in a gelatinous membrane that overlies the sensory epithelium in the inner ear. Gravity and acceleration cause the octoconia to deflect the stereocilia of sensory hair cells. Otoconia are required for normal processing of information regarding spatial orientation and acceleration.