OPN5

Opsin 5
Identifiers
SymbolsOPN5 ; GPR136; GRP136; PGR12; TMEM13
External IDsOMIM: 609042 MGI: 2662912 HomoloGene: 72341 IUPHAR: 161 GeneCards: OPN5 Gene
Orthologs
SpeciesHumanMouse
Entrez221391353344
EnsemblENSG00000124818ENSMUSG00000043972
UniProtQ6U736Q6VZZ7
RefSeq (mRNA)NM_001030051NM_181753
RefSeq (protein)NP_859528NP_861418
Location (UCSC)Chr 6:
47.75 – 47.8 Mb
Chr 17:
42.56 – 42.61 Mb
PubMed search

Opsin-5 is a protein that in humans is encoded by the OPN5 gene.[1][2][3] It is a photoreceptor protein sensitive to ultraviolent (UV) light. The OPN5 gene was discovered in mouse and human genomes and its mRNA expression was also discovered in neural tissues. Opsin-5 activates a UV-sensitive, heterotrimeric G protein Gi-mediated pathway in mammalian tissues.[4]

Function

Opsins are members of the G protein-coupled receptor superfamily. OPN5 is expressed in the eye, brain, testes, and spinal cord. This gene belongs to the seven-exon subfamily of mammalian opsin genes that includes peropsin (RRH) and retinal G protein coupled receptor (RGR). Like these other seven-exon opsin genes, this gene encodes a protein with photoisomerase activity. Alternative splicing results in multiple transcript variants encoding different isoforms.[3]

Photochemistry

Upon reconstitution with 11-cis-retinal, mouse Opn5 shows an absorption maximum of 380 nm. This causes the conversion of OPN5 into a blue-absorbing photoproduct (470 nm), which is stable in the dark. Orange illumination then causes its re-conversion back into the UV- absorbing state.[4]

References

  1. Tarttelin EE, Bellingham J, Hankins MW, Foster RG, Lucas RJ (2003). "Neuropsin (Opn5): a novel opsin identified in mammalian neural tissue". FEBS Lett. 554 (3): 410–6. doi:10.1016/S0014-5793(03)01212-2. PMID 14623103.
  2. Fredriksson R, Höglund PJ, Gloriam DE, Lagerström MC, Schiöth HB (2003). "Seven evolutionarily conserved human rhodopsin G protein-coupled receptors lacking close relatives". FEBS Lett. 554 (3): 381–8. doi:10.1016/S0014-5793(03)01196-7. PMID 14623098.
  3. 3.0 3.1 "Entrez Gene: OPN5 opsin 5".
  4. 4.0 4.1 Kojima D, Mori S, Torii M, Wada A, Morishita R, Fukada Y (2011). "UV-sensitive photoreceptor protein OPN5 in humans and mice". PLoS ONE 6 (10): e26388. doi:10.1371/journal.pone.0026388. PMC 3197025. PMID 22043319.

Further reading

This article incorporates text from the United States National Library of Medicine, which is in the public domain.