Overview
- Peptide (C)EKSLDESKNPARKLD, corresponding to amino acid residues 374 - 388 of mouse Otopetrin-1 (Accession Q80VM9). 4th intracellular loop.
- Rat kidney membranes; mouse heart, brain and tongue lysates (1:200-1:1000).
- Western blot analysis of rat kidney membranes (lanes 1 and 5), mouse heart lysate (lanes 2 and 6), mouse brain lysate (lanes 3 and 7) and rat tongue lysate (lanes 4 and 8):1-4. Anti-OTOP1 Antibody (#AHC-005), (1:200).
5-8. Anti-OTOP1 Antibody, preincubated with OTOP1 Blocking Peptide (#BLP-HC005).
Otopetrin-1 (Otop-1) is a proton channel involved in sour taste recognition. It belongs to the Otopetrin proton channel family together with Otopetrins-2 and 31. Otop-1 is a dimeric structure, with each subunit forming 12 transmembrane helices divided into structurally similar N- and C-domains2.
Taste recognition is very important because it enables to sample chemicals in the environment prior to digestion and hence, plays an important role in feeding and avoiding intoxication2. The sense of sour taste is caused by acids, and the first step in sour taste transduction is an influx of H+ ions through Otop-1 channel into the type three Taste Receptor Cells (TRCs). This leads to a decrease in intracellular pH and operation of a signaling cascade1-3.
Otop-1 is specifically expressed in type three taste cells and exhibits the Zn2+ sensitivity that is a key feature observed in the proton current of sour taste cells4.
Otop-1 also has a role in regulating intracellular Ca2+ levels required for the formation of otoconia in the vertebrate inner ear. Otoconia are complex calcium carbonate biominerals required for the sensation of gravity5.