# OGFr

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> Markdown URL: https://mediated.wiki/source/OGFr.md
> Source: https://en.wikipedia.org/wiki/OGFr
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Protein

OGFR Identifiers Aliases OGFR, OGFr, opioid growth factor receptor External IDs OMIM: 606459; MGI: 1919325; HomoloGene: 7199; GeneCards: OGFR; OMA:OGFR - orthologs Gene location (Human) Chr. Chromosome 20 (human)[1] Band 20q13.33 Start 62,804,835 bp[1] End 62,814,000 bp[1] Gene location (Mouse) Chr. Chromosome 2 (mouse)[2] Band 2|2 H4 Start 180,231,038 bp[2] End 180,237,629 bp[2] RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in granulocyte monocyte sural nerve right frontal lobe right lobe of liver spleen right lung right uterine tube cingulate gyrus olfactory zone of nasal mucosa Top expressed in yolk sac granulocyte ventricular zone mandibular prominence maxillary prominence thymus internal carotid artery ganglionic eminence mesenteric lymph nodes neural layer of retina More reference expression data BioGPS More reference expression data Gene ontology Molecular function protein binding G protein-coupled opioid receptor activity signaling receptor activity Cellular component membrane cytoplasm nucleus cellular component Biological process regulation of growth regulation of cell growth G protein-coupled opioid receptor signaling pathway signal transduction Sources:Amigo / QuickGO Orthologs Species Human Mouse Entrez 11054 72075 Ensembl ENSG00000060491 ENSMUSG00000049401 UniProt Q9NZT2 Q99PG2 RefSeq (mRNA) NM_007346 NM_031373 RefSeq (protein) NP_031372 NP_113550 Location (UCSC) Chr 20: 62.8 – 62.81 Mb Chr 2: 180.23 – 180.24 Mb PubMed search [3] [4] Wikidata View/Edit Human View/Edit Mouse

Protein family

Opioid growth factor receptor (OGFr) conserved region Identifiers Symbol OGFr_N Pfam PF04664 InterPro IPR006757 Available protein structures: PDB IPR006757 PF04664 (ECOD; PDBsum) AlphaFold IPR006757 PF04664

Protein family

Opioid growth factor receptor repeat Identifiers Symbol OGFr_III Pfam PF04680 InterPro IPR006770 Available protein structures: PDB IPR006770 PF04680 (ECOD; PDBsum) AlphaFold IPR006770 PF04680

**Opioid growth factor receptor**, also known as **OGFr** or the **ζ-opioid receptor**, is a [protein](/source/Protein) which in humans is encoded by the *OGFR* [gene](/source/Gene).[5][6] The protein encoded by this gene is a [receptor](/source/Receptor_(biochemistry)) for opioid growth factor (**OGF**), also known as [\[Met(5)\]-enkephalin](/source/Met-enkephalin). The endogenous ligand is thus a known [opioid peptide](/source/Opioid_peptide), and OGFr was originally discovered and named as a new [opioid receptor](/source/Opioid_receptor) zeta (ζ). However it was subsequently found that it shares little sequence similarity with the other opioid receptors, and has quite different function.

## Function

The natural function of this receptor appears to be in regulation of tissue growth,[7][8][9][10] and it has been shown to be important in embryonic development,[11] wound repair,[12] and certain forms of cancer.[13][14][15][16]

OGF is a negative regulator of cell proliferation and tissue organization in a variety of processes. The encoded unbound receptor for OGF has been localized to the outer nuclear envelope, where it binds OGF and is translocated into the nucleus. The coding sequence of this gene contains a polymorphic region of 60 nt tandem imperfect repeat units. Several transcripts containing between zero and eight repeat units have been reported.[5]

## Mechanism of activation

The opioid growth factor receptor consists of a chain of 677 amino acids, which includes a [nuclear localization sequence](/source/Nuclear_localization_sequence) region. When OGF binds to the receptor, an OGF-OGFr complex is formed, which leads to the increase in the synthesis of the selective [cyclin-dependent kinase](/source/Cyclin-dependent_kinase) (CDK) inhibitor proteins, p12 and [p16](/source/P16). [Retinoblastoma protein](/source/Retinoblastoma_protein) becomes inactivated through phosphorylation by CDKs, and leads to the progression of the cell cycle from the [G1 phase](/source/G1_phase) to the [S phase](/source/S_phase). Because the activation of the OGF receptor, blocks the phosphorylation of retinoblastoma proteins, retardation of the G1 phase occurs, which prevents the cell from further dividing.[17][18]

## Therapeutic applications

Upregulation of OGFr and consequent stimulation of the OGF-OGFr system are important for the anti-proliferative effects of imidazoquinoline drugs like [imiquimod](/source/Imiquimod) and [resiquimod](/source/Resiquimod), which are immune response modifiers with potent [antiviral](/source/Antiviral_drug) and [antitumour](/source/Antitumour) effects, used as topical creams for the treatment of [skin cancers](/source/Skin_cancer) and [warts](/source/Wart).[19]

## Structure

OGF contains a [conserved](/source/Conserved_sequence) [N-terminal](/source/N-terminal) [domain](/source/Protein_domain) followed by a series of imperfect [repeats](/source/Tandem_repeat).[8]

## References

1. ^ [***a***](#cite_ref-refGRCh38Ensembl_1-0) [***b***](#cite_ref-refGRCh38Ensembl_1-1) [***c***](#cite_ref-refGRCh38Ensembl_1-2) [GRCh38: Ensembl release 89: ENSG00000060491](http://May2017.archive.ensembl.org/Homo_sapiens/Gene/Summary?db=core;g=ENSG00000060491) – [Ensembl](/source/Ensembl_genome_database_project), May 2017

1. ^ [***a***](#cite_ref-refGRCm38Ensembl_2-0) [***b***](#cite_ref-refGRCm38Ensembl_2-1) [***c***](#cite_ref-refGRCm38Ensembl_2-2) [GRCm38: Ensembl release 89: ENSMUSG00000049401](http://May2017.archive.ensembl.org/Mus_musculus/Gene/Summary?db=core;g=ENSMUSG00000049401) – [Ensembl](/source/Ensembl_genome_database_project), May 2017

1. **[^](#cite_ref-3)** ["Human PubMed Reference:"](https://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Link&LinkName=gene_pubmed&from_uid=11054). *National Center for Biotechnology Information, U.S. National Library of Medicine*.

1. **[^](#cite_ref-4)** ["Mouse PubMed Reference:"](https://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Link&LinkName=gene_pubmed&from_uid=72075). *National Center for Biotechnology Information, U.S. National Library of Medicine*.

1. ^ [***a***](#cite_ref-entrez_5-0) [***b***](#cite_ref-entrez_5-1) ["Entrez Gene: OGFR opioid growth factor receptor"](https://www.ncbi.nlm.nih.gov/gene?Db=gene&Cmd=ShowDetailView&TermToSearch=11054).

1. **[^](#cite_ref-pmid10677613_6-0)** Zagon IS, Verderame MF, Allen SS, McLaughlin PJ (February 2000). "Cloning, sequencing, chromosomal location, and function of cDNAs encoding an opioid growth factor receptor (OGFr) in humans". *Brain Res*. **856** (1–2): 75–83. [doi](/source/Doi_(identifier)):[10.1016/S0006-8993(99)02330-6](https://doi.org/10.1016%2FS0006-8993%2899%2902330-6). [PMID](/source/PMID_(identifier)) [10677613](https://pubmed.ncbi.nlm.nih.gov/10677613). [S2CID](/source/S2CID_(identifier)) [37516655](https://api.semanticscholar.org/CorpusID:37516655).

1. **[^](#cite_ref-pmid9566952_7-0)** Wu Y, McLaughlin PJ, Zagon IS (April 1998). ["Ontogeny of the opioid growth factor, Met5-enkephalin, preproenkephalin gene expression, and the zeta opioid receptor in the developing and adult aorta of rat"](https://doi.org/10.1002%2F%28SICI%291097-0177%28199804%29211%3A4%3C327%3A%3AAID-AJA4%3E3.0.CO%3B2-J). *Dev. Dyn*. **211** (4): 327–37. [doi](/source/Doi_(identifier)):[10.1002/(SICI)1097-0177(199804)211:4<327::AID-AJA4>3.0.CO;2-J](https://doi.org/10.1002%2F%28SICI%291097-0177%28199804%29211%3A4%3C327%3A%3AAID-AJA4%3E3.0.CO%3B2-J). [PMID](/source/PMID_(identifier)) [9566952](https://pubmed.ncbi.nlm.nih.gov/9566952).

1. ^ [***a***](#cite_ref-pmid11890982_8-0) [***b***](#cite_ref-pmid11890982_8-1) Zagon IS, Verderame MF, McLaughlin PJ (February 2002). "The biology of the opioid growth factor receptor (OGFr)". *Brain Res. Brain Res. Rev*. **38** (3): 351–76. [doi](/source/Doi_(identifier)):[10.1016/S0165-0173(01)00160-6](https://doi.org/10.1016%2FS0165-0173%2801%2900160-6). [PMID](/source/PMID_(identifier)) [11890982](https://pubmed.ncbi.nlm.nih.gov/11890982). [S2CID](/source/S2CID_(identifier)) [37812525](https://api.semanticscholar.org/CorpusID:37812525).

1. **[^](#cite_ref-pmid15806307_9-0)** Malendowicz LK, Rebuffat P, Tortorella C, Nussdorfer GG, Ziolkowska A, Hochol A (May 2005). "Effects of met-enkephalin on cell proliferation in different models of adrenocortical-cell growth". *Int. J. Mol. Med*. **15** (5): 841–5. [doi](/source/Doi_(identifier)):[10.3892/ijmm.15.5.841](https://doi.org/10.3892%2Fijmm.15.5.841). [PMID](/source/PMID_(identifier)) [15806307](https://pubmed.ncbi.nlm.nih.gov/15806307).

1. **[^](#cite_ref-pmid18923142_10-0)** Cheng F, McLaughlin PJ, Verderame MF, Zagon IS (January 2009). ["The OGF-OGFr axis utilizes the p16INK4a and p21WAF1/CIP1 pathways to restrict normal cell proliferation"](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2613082). *Molecular Biology of the Cell*. **20** (1): 319–27. [doi](/source/Doi_(identifier)):[10.1091/mbc.E08-07-0681](https://doi.org/10.1091%2Fmbc.E08-07-0681). [PMC](/source/PMC_(identifier)) [2613082](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2613082). [PMID](/source/PMID_(identifier)) [18923142](https://pubmed.ncbi.nlm.nih.gov/18923142).

1. **[^](#cite_ref-pmid10519055_11-0)** Zagon IS, Wu Y, McLaughlin PJ (August 1999). "Opioid growth factor and organ development in rat and human embryos". *Brain Res*. **839** (2): 313–22. [doi](/source/Doi_(identifier)):[10.1016/S0006-8993(99)01753-9](https://doi.org/10.1016%2FS0006-8993%2899%2901753-9). [PMID](/source/PMID_(identifier)) [10519055](https://pubmed.ncbi.nlm.nih.gov/10519055). [S2CID](/source/S2CID_(identifier)) [22000619](https://api.semanticscholar.org/CorpusID:22000619).

1. **[^](#cite_ref-pmid12854052_12-0)** Sassani JW, Zagon IS, McLaughlin PJ (May 2003). "Opioid growth factor modulation of corneal epithelium: uppers and downers". *Curr. Eye Res*. **26** (5): 249–62. [doi](/source/Doi_(identifier)):[10.1076/ceyr.26.4.249.15427](https://doi.org/10.1076%2Fceyr.26.4.249.15427). [PMID](/source/PMID_(identifier)) [12854052](https://pubmed.ncbi.nlm.nih.gov/12854052). [S2CID](/source/S2CID_(identifier)) [34449136](https://api.semanticscholar.org/CorpusID:34449136).

1. **[^](#cite_ref-pmid10024694_13-0)** Zagon IS, Smith JP, McLaughlin PJ (March 1999). "Human pancreatic cancer cell proliferation in tissue culture is tonically inhibited by opioid growth factor". *Int. J. Oncol*. **14** (3): 577–84. [doi](/source/Doi_(identifier)):[10.3892/ijo.14.3.577](https://doi.org/10.3892%2Fijo.14.3.577). [PMID](/source/PMID_(identifier)) [10024694](https://pubmed.ncbi.nlm.nih.gov/10024694).

1. **[^](#cite_ref-pmid10200353_14-0)** McLaughlin PJ, Levin RJ, Zagon IS (May 1999). "Regulation of human head and neck squamous cell carcinoma growth in tissue culture by opioid growth factor". *Int. J. Oncol*. **14** (5): 991–8. [doi](/source/Doi_(identifier)):[10.3892/ijo.14.5.991](https://doi.org/10.3892%2Fijo.14.5.991). [PMID](/source/PMID_(identifier)) [10200353](https://pubmed.ncbi.nlm.nih.gov/10200353).

1. **[^](#cite_ref-pmid17974995_15-0)** Cheng F, Zagon IS, Verderame MF, McLaughlin PJ (November 2007). ["The opioid growth factor (OGF)-OGF receptor axis uses the p16 pathway to inhibit head and neck cancer"](https://doi.org/10.1158%2F0008-5472.CAN-07-1922). *Cancer Research*. **67** (21): 10511–8. [doi](/source/Doi_(identifier)):[10.1158/0008-5472.CAN-07-1922](https://doi.org/10.1158%2F0008-5472.CAN-07-1922). [PMID](/source/PMID_(identifier)) [17974995](https://pubmed.ncbi.nlm.nih.gov/17974995).

1. **[^](#cite_ref-pmid19297547_16-0)** Donahue RN, McLaughlin PJ, Zagon IS (March 2009). "Cell Proliferation of Human Ovarian Cancer is Regulated by the Opioid Growth Factor - Opioid Growth Factor Receptor Axis". *American Journal of Physiology. Regulatory, Integrative and Comparative Physiology*. **296** (6): R1716–25. [doi](/source/Doi_(identifier)):[10.1152/ajpregu.00075.2009](https://doi.org/10.1152%2Fajpregu.00075.2009). [PMID](/source/PMID_(identifier)) [19297547](https://pubmed.ncbi.nlm.nih.gov/19297547).

1. **[^](#cite_ref-Zagon_2009_17-0)** Zagon IS, Donahue RN, McLaughlin PJ (2009). "Opioid growth factor-opioid growth factor receptor axis is a physiological determinant of cell proliferation in diverse human cancers". *American Journal of Physiology. Regulatory, Integrative and Comparative Physiology*. **297** (4): R1154–61. [doi](/source/Doi_(identifier)):[10.1152/ajpregu.00414.2009](https://doi.org/10.1152%2Fajpregu.00414.2009). [PMID](/source/PMID_(identifier)) [19675283](https://pubmed.ncbi.nlm.nih.gov/19675283).

1. **[^](#cite_ref-Avella_2010_18-0)** Avella DM, Kimchi ET, Donahue RN, Tagaram HR, McLaughlin PJ, Zagon IS, Staveley-O'Carroll KF (2010). ["The opioid growth factor-opioid growth factor receptor axis regulates cell proliferation of human hepatocellular cancer"](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2828179). *American Journal of Physiology. Regulatory, Integrative and Comparative Physiology*. **298** (2): R459–66. [doi](/source/Doi_(identifier)):[10.1152/ajpregu.00646.2009](https://doi.org/10.1152%2Fajpregu.00646.2009). [PMC](/source/PMC_(identifier)) [2828179](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2828179). [PMID](/source/PMID_(identifier)) [19923357](https://pubmed.ncbi.nlm.nih.gov/19923357).

1. **[^](#cite_ref-pmid18480416_19-0)** Zagon IS, Donahue RN, Rogosnitzky M, McLaughlin PJ (August 2008). "Imiquimod upregulates the opioid growth factor receptor to inhibit cell proliferation independent of immune function". *Experimental Biology and Medicine*. **233** (8): 968–79. [doi](/source/Doi_(identifier)):[10.3181/0802-RM-58](https://doi.org/10.3181%2F0802-RM-58). [PMID](/source/PMID_(identifier)) [18480416](https://pubmed.ncbi.nlm.nih.gov/18480416). [S2CID](/source/S2CID_(identifier)) [35164284](https://api.semanticscholar.org/CorpusID:35164284).

## Further reading

- Zagon IS, Verderame MF, McLaughlin PJ (2002). "The biology of the opioid growth factor receptor (OGFr)". *Brain Res. Brain Res. Rev*. **38** (3): 351–76. [doi](/source/Doi_(identifier)):[10.1016/S0165-0173(01)00160-6](https://doi.org/10.1016%2FS0165-0173%2801%2900160-6). [PMID](/source/PMID_(identifier)) [11890982](https://pubmed.ncbi.nlm.nih.gov/11890982). [S2CID](/source/S2CID_(identifier)) [37812525](https://api.semanticscholar.org/CorpusID:37812525).

- Zagon IS, Verderame MF, Allen SS, McLaughlin PJ (2000). "Cloning, sequencing, chromosomal location, and function of cDNAs encoding an opioid growth factor receptor (OGFr) in humans". *Brain Res*. **856** (1–2): 75–83. [doi](/source/Doi_(identifier)):[10.1016/S0006-8993(99)02330-6](https://doi.org/10.1016%2FS0006-8993%2899%2902330-6). [PMID](/source/PMID_(identifier)) [10677613](https://pubmed.ncbi.nlm.nih.gov/10677613). [S2CID](/source/S2CID_(identifier)) [37516655](https://api.semanticscholar.org/CorpusID:37516655).

- Wu CJ, Yang XF, McLaughlin S, et al. (2000). ["Detection of a potent humoral response associated with immune-induced remission of chronic myelogenous leukemia"](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC381287). *J. Clin. Invest*. **106** (5): 705–14. [doi](/source/Doi_(identifier)):[10.1172/JCI10196](https://doi.org/10.1172%2FJCI10196). [PMC](/source/PMC_(identifier)) [381287](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC381287). [PMID](/source/PMID_(identifier)) [10974024](https://pubmed.ncbi.nlm.nih.gov/10974024).

- Hattori A, Okumura K, Nagase T, et al. (2001). ["Characterization of long cDNA clones from human adult spleen"](https://doi.org/10.1093%2Fdnares%2F7.6.357). *DNA Res*. **7** (6): 357–66. [doi](/source/Doi_(identifier)):[10.1093/dnares/7.6.357](https://doi.org/10.1093%2Fdnares%2F7.6.357). [PMID](/source/PMID_(identifier)) [11214971](https://pubmed.ncbi.nlm.nih.gov/11214971).

- Deloukas P, Matthews LH, Ashurst J, et al. (2002). ["The DNA sequence and comparative analysis of human chromosome 20"](https://doi.org/10.1038%2F414865a). *Nature*. **414** (6866): 865–71. [Bibcode](/source/Bibcode_(identifier)):[2001Natur.414..865D](https://ui.adsabs.harvard.edu/abs/2001Natur.414..865D). [doi](/source/Doi_(identifier)):[10.1038/414865a](https://doi.org/10.1038%2F414865a). [PMID](/source/PMID_(identifier)) [11780052](https://pubmed.ncbi.nlm.nih.gov/11780052).

- Strausberg RL, Feingold EA, Grouse LH, et al. (2003). ["Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences"](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC139241). *Proc. Natl. Acad. Sci. U.S.A*. **99** (26): 16899–903. [Bibcode](/source/Bibcode_(identifier)):[2002PNAS...9916899M](https://ui.adsabs.harvard.edu/abs/2002PNAS...9916899M). [doi](/source/Doi_(identifier)):[10.1073/pnas.242603899](https://doi.org/10.1073%2Fpnas.242603899). [PMC](/source/PMC_(identifier)) [139241](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC139241). [PMID](/source/PMID_(identifier)) [12477932](https://pubmed.ncbi.nlm.nih.gov/12477932).

- Zagon IS, Ruth TB, Leure-duPree AE, et al. (2003). "Immunoelectron microscopic localization of the opioid growth factor receptor (OGFr) and OGF in the cornea". *Brain Res*. **967** (1–2): 37–47. [doi](/source/Doi_(identifier)):[10.1016/S0006-8993(02)04172-0](https://doi.org/10.1016%2FS0006-8993%2802%2904172-0). [PMID](/source/PMID_(identifier)) [12650964](https://pubmed.ncbi.nlm.nih.gov/12650964). [S2CID](/source/S2CID_(identifier)) [30270018](https://api.semanticscholar.org/CorpusID:30270018).

- Ota T, Suzuki Y, Nishikawa T, et al. (2004). ["Complete sequencing and characterization of 21,243 full-length human cDNAs"](https://doi.org/10.1038%2Fng1285). *Nat. Genet*. **36** (1): 40–5. [doi](/source/Doi_(identifier)):[10.1038/ng1285](https://doi.org/10.1038%2Fng1285). [PMID](/source/PMID_(identifier)) [14702039](https://pubmed.ncbi.nlm.nih.gov/14702039).

- Gerhard DS, Wagner L, Feingold EA, et al. (2004). ["The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC)"](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC528928). *Genome Res*. **14** (10B): 2121–7. [doi](/source/Doi_(identifier)):[10.1101/gr.2596504](https://doi.org/10.1101%2Fgr.2596504). [PMC](/source/PMC_(identifier)) [528928](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC528928). [PMID](/source/PMID_(identifier)) [15489334](https://pubmed.ncbi.nlm.nih.gov/15489334).

- McLaughlin PJ, Zagon IS (2006). ["Progression of squamous cell carcinoma of the head and neck is associated with down-regulation of the opioid growth factor receptor"](https://doi.org/10.3892%2Fijo.28.6.1577). *Int. J. Oncol*. **28** (6): 1577–83. [doi](/source/Doi_(identifier)):[10.3892/ijo.28.6.1577](https://doi.org/10.3892%2Fijo.28.6.1577). [PMID](/source/PMID_(identifier)) [16685459](https://pubmed.ncbi.nlm.nih.gov/16685459).

- Zagon IS, McLaughlin PJ (2006). ["Opioid growth factor receptor is unaltered with the progression of human pancreatic and colon cancers"](https://doi.org/10.3892%2Fijo.29.2.489). *Int. J. Oncol*. **29** (2): 489–94. [doi](/source/Doi_(identifier)):[10.3892/ijo.29.2.489](https://doi.org/10.3892%2Fijo.29.2.489). [PMID](/source/PMID_(identifier)) [16820893](https://pubmed.ncbi.nlm.nih.gov/16820893).

- Olsen JV, Blagoev B, Gnad F, et al. (2006). ["Global, in vivo, and site-specific phosphorylation dynamics in signaling networks"](https://doi.org/10.1016%2Fj.cell.2006.09.026). *Cell*. **127** (3): 635–48. [doi](/source/Doi_(identifier)):[10.1016/j.cell.2006.09.026](https://doi.org/10.1016%2Fj.cell.2006.09.026). [PMID](/source/PMID_(identifier)) [17081983](https://pubmed.ncbi.nlm.nih.gov/17081983). [S2CID](/source/S2CID_(identifier)) [7827573](https://api.semanticscholar.org/CorpusID:7827573).

- McLaughlin PJ, Verderame MF, Hankins JL, Zagon IS (2007). ["Overexpression of the opioid growth factor receptor downregulates cell proliferation of human squamous carcinoma cells of the head and neck"](https://doi.org/10.3892%2Fijmm.19.3.421). *Int. J. Mol. Med*. **19** (3): 421–8. [doi](/source/Doi_(identifier)):[10.3892/ijmm.19.3.421](https://doi.org/10.3892%2Fijmm.19.3.421). [PMID](/source/PMID_(identifier)) [17273790](https://pubmed.ncbi.nlm.nih.gov/17273790).

v t e Cell surface receptor: G protein-coupled receptors Class A: Rhodopsin-like Neurotransmitter Adrenergic α1 A B D α2 A B C β1 β2 β3 Purinergic Adenosine A1 A2A A2B A3 P2Y 1 2 4 5 6 8 9 10 11 12 13 14 Serotonin (all but 5-HT3) 5-HT1 A B D E F 5-HT2 A B C 5-HT 4 5A 6 7 Other Acetylcholine M1 M2 M3 M4 M5 Dopamine D1 D2 D3 D4 D5 GHB receptor Histamine H1 H2 H3 H4 Melatonin 1A 1B 1C TAAR 1 2 5 6 8 9 Metabolites and signaling molecules Eicosanoid CysLT 1 2 LTB4 1 2 FPRL1 OXE Prostaglandin DP 1 2 EP 1 2 3 4 FP Prostacyclin Thromboxane Other Bile acid Cannabinoid CB1 CB2 GPR 18 55 119 EBI2 Estrogen Free fatty acid 1 2 3 4 Hydroxycarboxylic acids 1 2 3 Lysophosphatidic acid 1 2 3 4 5 6 Lysophospholipid 1 2 3 4 5 6 7 8 Oxoglutarate PAF Sphingosine-1-phosphate 1 2 3 4 5 Succinate Peptide Neuropeptide B/W 1 2 FF 1 2 S Y 1 2 4 5 Neuromedin B U 1 2 Neurotensin 1 2 Other Anaphylatoxin C3a C5a 1 2 Angiotensin 1 2 Apelin Bombesin BRS3 GRPR NMBR Bradykinin B1 B2 Chemerin 1 2 Chemokine Cholecystokinin A B Endothelin A B Formyl peptide 1 2 3 FSH Galanin 1 2 3 Gonadotropin-releasing hormone 1 2 Ghrelin Kisspeptin Luteinizing hormone/choriogonadotropin MAS 1 1L D E F G X1 X2 X3 X4 Melanocortin 1 2 3 4 5 MCHR 1 2 Motilin Opioid Delta Kappa Mu Nociceptin & Zeta, but not Sigma Orexin 1 2 Oxytocin Prokineticin 1 2 Prolactin-releasing peptide Relaxin 1 2 3 4 Somatostatin 1 2 3 4 5 Tachykinin 1 2 3 Thyrotropin Thyrotropin-releasing hormone Urotensin-II Vasopressin 1A 1B 2 Miscellaneous Taste, bitter TAS2R 1 3 4 5 7 8 9 10 13 14 16 19 20 30 31 38 39 40 41 42 43 45 46 50 60 Vomeronasal receptor type 1 Orphan GPR 3 4 6 12 15 17 18 19 20 21 22 26 27 31 32 33 34 35 37 39 42 45 50 52 55 61 62 63 65 68 75 78 82 83 84 85 87 88 101 103 109A 119 132 135 137B 139 141 142 146 148 149 150 151 152 153 160 161 162 171 173 174 176 177 182 183 Other Adrenomedullin Olfactory Opsin 3 4 5 1LW 1MW 1SW RGR RRH Protease-activated 1 2 3 4 SREB 1 2 3 Class B: Secretin-like Adhesion ADGRB Brain-specific angiogenesis inhibitor 1 2 3 ADGRC Cadherin 1 2 3 ADGRE EMR 1 2 3 CD97 ADGRG 1 2 3 4 5 6 7 ADGRL Latrophilin 1 2 3 ELTD1 Orphan GPR 56 64 97 98 110 111 112 113 114 115 116 123 124 125 126 128 133 143 144 155 157 Other Calcitonin CALCRL Corticotropin-releasing hormone 1 2 Glucagon GR GIPR GLP1R GLP2R Growth-hormone-releasing hormone PACAPR1 GPR Methuselah-like proteins Parathyroid hormone 1 2 Secretin Vasoactive intestinal peptide 1 2 Class C: Metabotropic glutamate / pheromone Taste, sweet TAS1R 1 2 3 Vomeronasal receptor, type 2 Other Calcium-sensing receptor GABAB 1 2 Glutamate receptor Metabotropic glutamate 1 2 3 4 5 6 7 8 GPRC6A GPR 156 158 179 RAIG 1 2 3 4 Class F: Frizzled & Smoothened Frizzled Frizzled 1 2 3 4 5 6 7 8 9 10 Smoothened Smoothened Category Commons

This article incorporates text from the public domain [Pfam](/source/Pfam) and [InterPro](/source/InterPro): [IPR006757](https://www.ebi.ac.uk/interpro/entry/IPR006757)

This article incorporates text from the public domain [Pfam](/source/Pfam) and [InterPro](/source/InterPro): [IPR006770](https://www.ebi.ac.uk/interpro/entry/IPR006770)

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Adapted from the Wikipedia article [OGFr](https://en.wikipedia.org/wiki/OGFr) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/OGFr?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.