OPN5

OPN5
Identifiers
Aliases	OPN5 , GPR136, GRP136, PGR12, TMEM13, opsin 5
External IDs	OMIM: 609042 MGI: 2662912 HomoloGene: 72341 GeneCards: OPN5
Gene location (Human)
Chr.	Chromosome 6 (human)
End	47,832,780 bp
Gene location (Mouse)
Chr.	Chromosome 17 (mouse)
End	42,922,286 bp
RNA expression pattern
	Top expressed in
	left ventricle; ; lower lobe of lung; ; Brodmann area 9; ; prefrontal cortex; ; superior frontal gyrus; ; hypothalamus; ; right uterine tube; ; putamen; ; cell; ; human musculoskeletal system;
	n/a
	More reference expression data
	n/a
Gene ontology
Molecular function	11-cis retinal binding ; G protein-coupled receptor activity ; photoreceptor activity ; signal transducer activity ; G protein-coupled photoreceptor activity ;
Cellular component	integral component of membrane ; membrane ; photoreceptor outer segment ; integral component of plasma membrane ;
Biological process	signal transduction ; visual perception ; response to stimulus ; G protein-coupled receptor signaling pathway ; phototransduction ; detection of visible light ; cellular response to light stimulus ;
	Sources:Amigo / QuickGO
Orthologs
	221391
	353344
	ENSG00000124818
	ENSMUSG00000043972
	Q6U736
	Q6VZZ7
	NM_001030051 ; NM_181744
	NM_181753
	NP_859528
	NP_861418
	Wikidata
View/Edit Human	View/Edit Mouse

Last updated January 03, 2024

Opsin-5, also known as G-protein coupled receptor 136 or neuropsin is a protein that in humans is encoded by the OPN5 gene. Opsin-5 is a member of the opsin subfamily of the G protein-coupled receptors.^[5]^[6]^[7] It is a photoreceptor protein sensitive to ultraviolet (UV) light. The OPN5 gene was discovered in mouse and human genomes and its mRNA expression was also found in neural tissues. Neuropsin is bistable at 0 °C and activates a UV-sensitive, heterotrimeric G protein Gi-mediated pathway in mammalian and avian tissues.^[8]^[9]

Function

Human neuropsin is expressed in the eye, brain, testes, and spinal cord. Neuropsin belongs to the seven-exon subfamily of mammalian opsin genes that includes peropsin (RRH) and retinal G protein coupled receptor (RGR). Neuropsin has different isoforms created by alternative splicing.^[7]

Photochemistry

When reconstituted with 11-cis-retinal, mouse and human neuropsins absorb maximally at 380 nm. When illuminated these neuropsins are converted into blue-absorbing photoproducts (470 nm), which are stable in the dark. The photoproducts are converted back to the UV-absorbing form, when they are illuminated with orange light (> 520 nm).^[8]

Species distribution

Neuropsins are known from echinoderms,^[10] annelids, arthropods, brachiopods, tardigrades, mollusks, and most are known from craniates.^[11] The craniates are the taxon that contains mammals and with them humans. However, neuropsin orthologs have only been experimentally verified in a small number of animals, among them human, mouse ( Mus musculus ),^[5] chicken ( Gallus gallus domesticus ),^[9]^[12] the Japanese quail (Coturnix japonica),^[13] the European brittle star Amphiura filiformis (related to starfish),^[10] the tardigrade water bear ( Hypsibius dujardini ),^[14] and the tadpole of Xenopus laevis .^[15]

Searches of publicly available databases of genetic sequences have found putative neuropsin orthologs in both major branches of Bilateria: protostomes and deuterostomes. Among protostomes, putative neuropsins have been found in the molluscs owl limpet ( Lottia gigantea ) (a species of sea snail) and Pacific oyster (Crassostrea gigas), in the water flea ( Daphnia pulex ) (an arthropod), and in the annelid worm Capitella teleta .^[14]

Phylogeny

The neuropsins are one of three subgroups of the tetraopsins (also known as RGR/Go or Group 4 opsins). The other groups are the chromopsins and the Go-opsins. The tetraopsins are one of the five major groups of the animal opsins, also known as type 2 opsins). The other groups are the ciliary opsins (c-opsins, cilopsins), the rhabdomeric opsins (r-opsins, rhabopsins), the xenopsins, and the nessopsins. Four of these subclades occur in Bilateria (all but the nessopsins).^[11]^[16] However, the bilaterian clades constitute a paraphyletic taxon without the opsins from the cnidarians.^[11]^[16]^[17]^[18]

The phylogenetic relationship of the neuropsins to the other opsins

Phylogenetic reconstruction of the opsins. The outgroup contains other G protein-coupled receptors. The frame highlights the tetraopsins, which are expanded in the next image.
Phylogenetic reconstruction of the tetraopsins. The outgroup contains other G protein-coupled receptors including the other opsins. The frame highlights the neuropsins, which are expanded in the next image.

In the phylogeny above, Each clade contains sequences from opsins and other G protein-coupled receptors. The number of sequences and two pie charts are shown next to the clade. The first pie chart shows the percentage of a certain amino acid at the position in the sequences corresponding to position 296 in cattle rhodopsin. The amino acids are color-coded. The colors are red for lysine (K), purple for glutamic acid (E), dark and mid-gray for other amino acids, and light gray for sequences that have no data at that position. The second pie chart gives the taxon composition for each clade, green stands for craniates, dark green for cephalochordates, mid green for echinoderms, pale pink for annelids, dark blue for arthropods, light blue for mollusks, and purple for cnidarians. The branches branches to the clades have pie charts, which give support values for the branches. The values are from right to left SH-aLRT/aBayes/UFBoot. The branches are considered supported when SH-aLRT ≥ 80%, aBayes ≥ 0.95, and UFBoot ≥ 95%. If a support value is above its threshold the pie chart is black otherwise gray.^[11]

Related Research Articles

Melanopsin is a type of photopigment belonging to a larger family of light-sensitive retinal proteins called opsins and encoded by the gene Opn4. In the mammalian retina, there are two additional categories of opsins, both involved in the formation of visual images: rhodopsin and photopsin in the rod and cone photoreceptor cells, respectively.

Animal opsins are G-protein-coupled receptors and a group of proteins made light-sensitive via a chromophore, typically retinal. When bound to retinal, opsins become retinylidene proteins, but are usually still called opsins regardless. Most prominently, they are found in photoreceptor cells of the retina. Five classical groups of opsins are involved in vision, mediating the conversion of a photon of light into an electrochemical signal, the first step in the visual transduction cascade. Another opsin found in the mammalian retina, melanopsin, is involved in circadian rhythms and pupillary reflex but not in vision. Humans have in total nine opsins. Beside vision and light perception, opsins may also sense temperature, sound, or chemicals.

Rhodopsin kinase is a serine/threonine-specific protein kinase involved in phototransduction. This enzyme catalyses the following chemical reaction:

Retinylidene proteins, or rhodopsins in a broad sense, are proteins that use retinal as a chromophore for light reception. They are the molecular basis for a variety of light-sensing systems from phototaxis in flagellates to eyesight in animals. Retinylidene proteins include all forms of opsin and rhodopsin. While rhodopsin in the narrow sense refers to a dim-light visual pigment found in vertebrates, usually on rod cells, rhodopsin in the broad sense refers to any molecule consisting of an opsin and a retinal chromophore in the ground state. When activated by light, the chromophore is isomerized, at which point the molecule as a whole is no longer rhodopsin, but a related molecule such as metarhodopsin. However, it remains a retinylidene protein. The chromophore then separates from the opsin, at which point the bare opsin is a retinylidene protein. Thus, the molecule remains a retinylidene protein throughout the phototransduction cycle.

The photoreceptor cell-specific nuclear receptor (PNR), also known as NR2E3, is a protein that in humans is encoded by the NR2E3 gene. PNR is a member of the nuclear receptor super family of intracellular transcription factors.

Lysophosphatidic acid receptor 4 also known as LPA₄ is a protein that in humans is encoded by the LPAR4 gene. LPA₄ is a G protein-coupled receptor that binds the lipid signaling molecule lysophosphatidic acid (LPA).

Peropsin, a visual pigment-like receptor, is a protein that in humans is encoded by the RRH gene. It belongs like other animal opsins to the G protein-coupled receptors. Even so, the first peropsins were already discovered in mice and humans in 1997, not much is known about them.

Probable G-protein coupled receptor 135 is a protein that in humans is encoded by the GPR135 gene.

G-protein coupled receptor 161 is a protein that in humans is encoded by the GPR161 gene.

Probable G-protein coupled receptor 176 is a protein that in humans is encoded by the GPR176 gene.

RPE-retinal G protein-coupled receptor also known as RGR-opsin is a protein that in humans is encoded by the RGR gene. RGR-opsin is a member of the rhodopsin-like receptor subfamily of GPCR. Like other opsins which bind retinaldehyde, it contains a conserved lysine residue in the seventh transmembrane domain. RGR-opsin comes in different isoforms produced by alternative splicing.

Arrestin-C, also known as retinal cone arrestin-3, is a protein that in humans is encoded by the ARR3 gene.

Olfactory receptor 2L2 is a protein that in humans is encoded by the OR2L2 gene.

Olfactory receptor 52A1 is a protein that in humans is encoded by the OR52A1 gene.

Olfactory receptor 7A5 is a protein that in humans is encoded by the OR7A5 gene.

Olfactory receptor 2H1 is a protein that in humans is encoded by the OR2H1 gene.

Olfactory receptor 2J2 is a protein that in humans is encoded by the OR2J2 gene.

Olfactory receptor 2AG1 is a protein that in humans is encoded by the OR2AG1 gene.

Olfactory receptor 51I2 is a protein that in humans is encoded by the OR51I2 gene.

Retinal degeneration is a retinopathy which consists in the deterioration of the retina caused by the progressive death of its cells. There are several reasons for retinal degeneration, including artery or vein occlusion, diabetic retinopathy, R.L.F./R.O.P., or disease. These may present in many different ways such as impaired vision, night blindness, retinal detachment, light sensitivity, tunnel vision, and loss of peripheral vision to total loss of vision. Of the retinal degenerative diseases retinitis pigmentosa (RP) is a very important example.

References

1 2 3 GRCh38: Ensembl release 89: ENSG00000124818 - Ensembl, May 2017
1 2 3 GRCm38: Ensembl release 89: ENSMUSG00000043972 - Ensembl, May 2017
↑ "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
↑ "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
1 2 Tarttelin EE, Bellingham J, Hankins MW, Foster RG, Lucas RJ (Nov 2003). "Neuropsin (Opn5): a novel opsin identified in mammalian neural tissue". FEBS Letters. 554 (3): 410–6. doi: 10.1016/S0014-5793(03)01212-2 . PMID 14623103. S2CID 9577067.
↑ Fredriksson R, Höglund PJ, Gloriam DE, Lagerström MC, Schiöth HB (Nov 2003). "Seven evolutionarily conserved human rhodopsin G protein-coupled receptors lacking close relatives". FEBS Letters. 554 (3): 381–8. doi: 10.1016/S0014-5793(03)01196-7 . PMID 14623098. S2CID 11563502.
1 2 "Entrez Gene: OPN5 opsin 5".
1 2 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. Bibcode:2011PLoSO...626388K. doi: 10.1371/journal.pone.0026388 . PMC 3197025 . PMID 22043319.
1 2 Yamashita T, Ohuchi H, Tomonari S, Ikeda K, Sakai K, Shichida Y (December 2010). "Opn5 is a UV-sensitive bistable pigment that couples with Gi subtype of G protein". Proceedings of the National Academy of Sciences of the United States of America. 107 (51): 22084–22089. Bibcode:2010PNAS..10722084Y. doi: 10.1073/pnas.1012498107 . PMC 3009823 . PMID 21135214.
1 2 Delroisse J, Ullrich-Lüter E, Ortega-Martinez O, Dupont S, Arnone MI, Mallefet J, Flammang P (2014). "High opsin diversity in a non-visual infaunal brittle star". BMC Genomics. 15 (1): 1035. doi: 10.1186/1471-2164-15-1035 . PMC 4289182 . PMID 25429842.
1 2 3 4 Gühmann M, Porter ML, Bok MJ (August 2022). "The Gluopsins: Opsins without the Retinal Binding Lysine". Cells. 11 (15): 2441. doi: 10.3390/cells11152441 . PMC 9368030 . PMID 35954284. Material was copied and adapted from this source, which is available under a Creative Commons Attribution 4.0 International License.
↑ Tomonari S, Migita K, Takagi A, Noji S, Ohuchi H (Jul 2008). "Expression patterns of the opsin 5-related genes in the developing chicken retina". Developmental Dynamics. 237 (7): 1910–22. doi: 10.1002/dvdy.21611 . PMID 18570255. S2CID 42113764.
↑ Nakane Y, Ikegami K, Ono H, Yamamoto N, Yoshida S, Hirunagi K, Ebihara S, Kubo Y, Yoshimura T (Aug 2010). "A mammalian neural tissue opsin (Opsin 5) is a deep brain photoreceptor in birds". Proceedings of the National Academy of Sciences of the United States of America. 107 (34): 15264–8. Bibcode:2010PNAS..10715264N. doi: 10.1073/pnas.1006393107 . PMC 2930557 . PMID 20679218.
1 2 Hering L, Mayer G (Sep 2014). "Analysis of the opsin repertoire in the tardigrade Hypsibius dujardini provides insights into the evolution of opsin genes in panarthropoda". Genome Biology and Evolution. 6 (9): 2380–91. doi:10.1093/gbe/evu193. PMC 4202329 . PMID 25193307.
↑ Currie SP, Doherty GH, Sillar KT (May 2016). "Deep-brain photoreception links luminance detection to motor output in Xenopus frog tadpoles". Proceedings of the National Academy of Sciences of the United States of America. 113 (21): 6053–6058. Bibcode:2016PNAS..113.6053C. doi: 10.1073/pnas.1515516113 . PMC 4889350 . PMID 27166423.
1 2 Ramirez MD, Pairett AN, Pankey MS, Serb JM, Speiser DI, Swafford AJ, Oakley TH (26 October 2016). "The last common ancestor of most bilaterian animals possessed at least 9 opsins". Genome Biology and Evolution: evw248. doi: 10.1093/gbe/evw248 . PMC 5521729 . PMID 27797948.
↑ Porter ML, Blasic JR, Bok MJ, Cameron EG, Pringle T, Cronin TW, Robinson PR (January 2012). "Shedding new light on opsin evolution". Proceedings. Biological Sciences. 279 (1726): 3–14. doi:10.1098/rspb.2011.1819. PMC 3223661 . PMID 22012981.
↑ Liegertová M, Pergner J, Kozmiková I, Fabian P, Pombinho AR, Strnad H, et al. (July 2015). "Cubozoan genome illuminates functional diversification of opsins and photoreceptor evolution". Scientific Reports. 5: 11885. Bibcode:2015NatSR...511885L. doi:10.1038/srep11885. PMC 5155618 . PMID 26154478.