GPR18 Membrane Protein Introduction

Introduction of GPR18

GPR18 is encoded by the GPR18 gene. GPR18 belongs to the class A G-protein-coupled receptor family which has been implicated in the tumorigenesis and metastasis of human cancers and is considered amongst the most desirable targets for drug development. GPR18 is comprised of 338 amino acid in human and it’ s gene located at 3q26.2-q27. It is expressed in midpiece of spermatozoon (at protein level), most abundant in testis and spleen, highly expressed in CD4 and CD8-positive T-cells as well as CD19-positive B-cells.

Basic Information of GPR18
Protein Name N-arachidonyl glycine receptor
Gene Name GPR18
Aliases G-protein coupled receptor 18, NAGly receptor
Organism Homo sapiens (Human)
UniProt ID Q14330
Transmembrane Times 7
Length (aa) 331

Function of GPR18 Membrane Protein

GPR18 is amply expressed in lymphocytes, with particularly high expression in CD8αα γδT intraepithelial lymphocytes (IELs), and it functions in establishing an IEL compartment of normal size. At the same time, small molecule agonists of GPR18 might augment the size of the KLRG1+ effector CD8 T cell compartment, which might be useful, for example, during viral responses or in the context of tumor immunotherapy. Moreover, it has revealed that GPR18 is also associated with apoptosis and cell cycle arrest of prostate cancer cells. GPR18 transcription levels in the prostate cancer tissue samples and cell lines, such as PC-3, LNCaP, DU145, and 22Rv1 cells, were obviously higher than that seen in normal prostate tissue and cells, and scientists have proved that the expression level of endogenous GPR18 is associated with the pathogenesis of prostate cancer. Beyond that, knockdown of GPR18 in prostate cancer cells increased the expression of caspase 1 and IL6, induced cell cycle arrest and apoptosis.

Homology model of GPR18 receptor structure Fig.1 Homology model of GPR18 receptor structure (Kothandan, 2013).

Application of GPR18 Membrane Protein in Literature

  1. Rajaraman G., et al. G protein coupled receptor 18: A potential role for endocannabinoid signaling in metabolic dysfunction. Molecular Nutrition & Food Research. 2016, 60(1), 92-102. PubMed ID: 26337420

    This review explores the current scientific knowledge on GPR18 including its localization, signaling pathways, and pharmacology. Importantly, the involvement of nutritional factors and potential dietary regulation of GPR18 and its (patho)physiological roles are described.

  2. Nazir M., et al. GPR18 Inhibiting Amauromine and the Novel Triterpene Glycoside Auxarthonoside from the Sponge-Derived Fungus Auxarthron reticulatum. Planta Medica. 2015, 81(12/13), 1141-1145. PubMed ID: 26287693

    This article reveals that amauromine shows antagonistic activity at the cannabinoid-like orphan receptor GPR18. The diketopiperazine 1 may thus serve as a lead structure for the development of more potent and selective GPR18 antagonists, which are required to study the orphan receptor's potential as a new drug target.

  3. Rempel V., et al. Bicyclic imidazole-4-one derivatives: a new class of antagonists for the orphan G protein-coupled receptors GPR18 and GPR55. Med.chem.commun. 2014, 5(5), 632-649.

    This article reveals that the most potent GPR18 antagonist was (Z)-2-(3-(4-chlorobenzyloxy)benzylidene)-6,7-dihydro-2H-imidazo[2,1b][1,3]thiazin-3(5H)-one representing the first selective GPR18 antagonist.

  4. Harms H., et al. Indoloditerpenes from a marine-derived fungal strain of Dichotomomyces cejpii with antagonistic activity at GPR18 and cannabinoid receptors. Journal of Natural Products. 2014, 77(3), 673. PubMed ID: 24471526

    This article identifies 27-O-methylasporyzin C as the first selective GPR18 antagonist with an indole structure. The new natural indole derivatives may serve as lead structures for the development of GPR18- and CB receptor-blocking drugs.

GPR18 Preparation Options

To obtain the soluble and functional target protein, the versatile Magic™ membrane protein production platform in Creative Biolabs enables many flexible options, from which you can always find a better match for your particular project. Aided by our versatile Magic™ anti-membrane protein antibody discovery platform, we also provide customized anti-GPR18 antibody development services.

As a forward-looking research institute as well as a leading customer service provider in the field of membrane protein, Creative Biolabs has won good reputation among our worldwide customers for successfully accomplishing numerous challenging projects including generation of many functional membrane proteins. Please feel free to contact us for more information.


  1. Kothandan G and Cho S J, (2013). Homology modeling of gpr18 receptor, an orphan g-protein-coupled receptor. 조선자연과학논문집. 6(1).

All listed customized services & products are for research use only, not intended for pharmaceutical, diagnostic, therapeutic or any in vivo human use.

Online Inquiry

Verification code
Click image to refresh the verification code.


USA: 45-1 Ramsey Road, Shirley, NY 11967, USA
Europe: Heidenkampsweg 58, 20097 Hamburg, Germany
Call us at:
USA: 1-631-381-2994
Europe: 44-207-097-1828
Fax: 1-631-207-8356
Our customer service representatives are available 24 hours a day, 7 days a week. Contact Us