Otopetrin family
The otopetrin family is a group of proteins that were first identified based on their essential role in the vestibular system, and were later shown to be expressed in many different tissues, including taste receptor cells.[1] They are named after the Greek word "o̱tós," which means ear and "pétrā," which means rock, in reference to their role in the formation of otoconia/otoliths in the inner ear. The secondary structure of otopetrin-1 (OTOP1) is predicted to include 12 transmembrane domains, with three conserved sub-domains (OD-1 to OD-III).[2] Otopetrins were initially thought to modulate calcium homeostasis and influx of calcium in response to extracellular ATP[3] but were subsequently shown to form proton-selective ion channels.[1]
| Otopetrin | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| Symbol | Otopetrin | ||||||||
| Pfam | PF03189 | ||||||||
| InterPro | IPR004878 | ||||||||
| TCDB | 1.A.110 | ||||||||
| OPM superfamily | 545 | ||||||||
| OPM protein | 6o84 | ||||||||
| |||||||||
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.[3][4][5]
Otopetrin-1 was recently found to be an essential sour taste receptor,[6] by its interaction with KIR.[7]
References
- Tu YH, Cooper AJ, Teng B, Chang RB, Artiga DJ, Turner HN, Mulhall EM, Ye W, Smith AD, Liman ER (March 2018). "An evolutionarily conserved gene family encodes proton-selective ion channels". Science. 359 (6379): 1047–1050. Bibcode:2018Sci...359.1047T. doi:10.1126/science.aao3264. PMC 5845439. PMID 29371428.
- Hughes I, Binkley J, Hurle B, Green ED, Sidow A, Ornitz DM (February 2008). "Identification of the Otopetrin Domain, a conserved domain in vertebrate otopetrins and invertebrate otopetrin-like family members". BMC Evolutionary Biology. 8: 41. doi:10.1186/1471-2148-8-41. PMC 2268672. PMID 18254951.
- Hughes I, Saito M, Schlesinger PH, Ornitz DM (July 2007). "Otopetrin 1 activation by purinergic nucleotides regulates intracellular calcium". Proceedings of the National Academy of Sciences of the United States of America. 104 (29): 12023–8. Bibcode:2007PNAS..10412023H. doi:10.1073/pnas.0705182104. PMC 1924595. PMID 17606897.
- Söllner C, Schwarz H, Geisler R, Nicolson T (December 2004). "Mutated otopetrin 1 affects the genesis of otoliths and the localization of Starmaker in zebrafish". Development Genes and Evolution. 214 (12): 582–90. doi:10.1007/s00427-004-0440-2. PMID 15480759. S2CID 1581286.
- Hughes I, Blasiole B, Huss D, Warchol ME, Rath NP, Hurle B, Ignatova E, Dickman JD, Thalmann R, Levenson R, Ornitz DM (December 2004). "Otopetrin 1 is required for otolith formation in the zebrafish Danio rerio". Developmental Biology. 276 (2): 391–402. doi:10.1016/j.ydbio.2004.09.001. PMC 2522322. PMID 15581873.
- Zhang J, Jin H, Zhang W, Ding C, O Keeffe S, Ye M, Zuker CS (October 2019). "Sour Sensing from the Tongue to the Brain". Cell. 179 (2): 392–402. doi:10.1016/j.cell.2019.08.031. PMID 31543264.
- Ye W, Chang RB, Bushman JD, Tu YH, Mulhall EM, Wilson CE, Cooper AJ, Chick WS, Hill-Eubanks DC, Nelson MT, Kinnamon SC, Liman ER (2016). "The K+ channel KIR2.1 functions in tandem with proton influx to mediate sour taste transduction". Proc Natl Acad Sci U S A. 113 (2): E229–238. Bibcode:2016PNAS..113E.229Y. doi:10.1073/pnas.1514282112. PMC 4720319. PMID 26627720.
Further reading
- Hurle B, Marques-Bonet T, Antonacci F, Hughes I, Ryan JF, Eichler EE, Ornitz DM, Green ED (January 2011). "Lineage-specific evolution of the vertebrate Otopetrin gene family revealed by comparative genomic analyses". BMC Evolutionary Biology. 11: 23. doi:10.1186/1471-2148-11-23. PMC 3038909. PMID 21261979.