Cloning and Characterization of a Novel Orphan G-Protein-Coupled Receptor Localized to Human Chromosome 2p16

doi:10.1006/bbrc.1999.0753

Biochemical and Biophysical Research Communications

Volume 260, Issue 1, 24 June 1999, Pages 174-180

https://doi.org/10.1006/bbrc.1999.0753 Get rights and content

Abstract

We report the identification and characterisation of a novel human orphan G-protein-coupled receptor (GPR) which maps to chromosome 2p16. We have determined the full-length coding sequence and genomic structure of a gene corresponding to the anonymous expressed sequenced tag, WI-31133. This gene encodes a novel protein that is 540 amino acids in length. Protein sequence analysis predicts the presence of seven transmembrane domains, a characteristic feature of GPRs. In situ hybridisation to human retina and Northern blot analysis of human retinal pigment epithelium (RPE) showed localisation of this transcript to the RPE and cells surrounding retinal arterioles. In contrast, the transcript was localised to the photoreceptor inner segments and the outer plexiform layer in mouse sections. Northern blot analysis demonstrated a 7 kb transcript highly expressed in the brain. No mutations were identified during a screen of patients suffering from Doyne's honeycomb retinal dystrophy (DHRD), an inherited retinal degeneration which maps to chromosome 2p16.

References (17)

J. Nathans et al.
Cell
(1983)
A. Gal et al.
Progress in Retinal and Eye Research
(1997)
G.G. Lennon et al.
Genomics
(1996)
S.R. Robinson et al.
Neurosci. Lett.
(1989)
H.G. Dohlman et al.
Ann. Rev. Biochem.
(1991)
C.Y. Gregory et al.
Hum. Mol. Genet.
(1996)
S. Kermani et al.
Hum. Genet.
(1999)
S.F. Altschul et al.
Nuc. Acids Res.
(1997)

There are more references available in the full text version of this article.

Cited by (20)

Global and endothelial G-protein coupled receptor 75 (GPR75) knockout relaxes pulmonary artery and mitigates hypoxia-induced pulmonary hypertension
2023, Vascular Pharmacology
Pulmonary hypertension (PH) is a multifactorial disease with a poor prognosis and inadequate treatment options. We found two-fold higher expression of the orphan G-Protein Coupled Receptor 75 (GPR75) in leukocytes and pulmonary arterial smooth muscle cells from idiopathic PH patients and from lungs of C57BL/6 mice exposed to hypoxia. We therefore postulated that GPR75 signaling is critical to the pathogenesis of PH.
To test this hypothesis, we exposed global (Gpr75^−/−) and endothelial cell (EC) GPR75 knockout (EC-Gpr75^−/−) mice and wild-type (control) mice to hypoxia (10% oxygen) or normal atmospheric oxygen for 5 weeks. We then recorded echocardiograms and performed right heart catheterizations.
Chronic hypoxia increased right ventricular systolic and diastolic pressures in wild-type mice but not Gpr75^−/− or EC-Gpr75^−/− mice. In situ hybridization and qPCR results revealed that Gpr75 expression was increased in the alveoli, airways and pulmonary arteries of mice exposed to hypoxia. In addition, levels of chemokine (CC motif) ligand 5 (CCL5), a low affinity ligand of GPR75, were increased in the lungs of wild-type, but not Gpr75^−/−, mice exposed to hypoxia, and CCL5 enhanced hypoxia-induced contraction of intra-lobar pulmonary arteries in a GPR75-dependent manner. Gpr75 knockout also increased pulmonary cAMP levels and decreased contraction of intra-lobar pulmonary arteries evoked by endothelin-1 or U46619 in cAMP-protein kinase A-dependent manner.
These results suggest GPR75 has a significant role in the development of hypoxia-induced PH.
GPR75: An exciting new target in metabolic syndrome and related disorders
2022, Biochimie
Citation Excerpt :
For a detailed understanding of GPCRs structure and functions in drug discovery, the readers may consider reading a recent review report by Yang et al. [24]. Tarttelin et al., 1999 reported the discovery of GRP75 that mapped to the human chromosome 2p16 within a single exon and encodes a 540 amino-acids protein [25]. Though, GPR75 expresses the characteristic structural features of GPCRs, namely seven transmembrane spanning domains, N-glycosylation sites in the N-terminus, and numerous serine and threonine phosphorylation sites in the C-terminus, it shares less structural homology with other receptors of the same class [26].
The metabolic syndrome is a plethora of related disorders that are frequently associated with morbidity and mortality in addition to economic burden. While various treatment options are available, the need to understand the pathology and find new targets still remains. Recent data have suggested GPR75 as one such exciting target that has shown to a highly druggable potential. In this review, we have discussed the recent findings on GPR75 in terms of its expression and signaling and the way it could be a novel target in diseases associated with metabolic syndrome including obesity, dyslipidemia, diabetes, cardiovascular disease, and cerebrovascular disease. In addition, the opportunities and challenges related with the druggable potential of GPR75 have also been highlighted in this review.
The CYP/20-HETE/GPR75 axis in hypertension
2022, Advances in Pharmacology
Citation Excerpt :
In VSMCs, 20-HETE sensitization of the contractile apparatus is mediated via inhibition of the BKca channel and activation of the L-type Ca channel (Miyata & Roman, 2005; Randriamboavonjy, Busse, & Fleming, 2003; Zou et al., 1996). These extensively studied signaling pathways hinted at the presence of a G-protein coupled receptor, which was identified by Garcia and colleagues to be GPR75, a member of the Gq-coupled Rhodopsin subfamily of receptors (Tarttelin et al., 1999). GPR75 is a high affinity 20HR essential for the binding of 20-HETE and activation of these downstream signals (Garcia et al., 2017; Pascale et al., 2021).
20-Hydroxyeicosatetraenoic acid (20-HETE) is a bioactive lipid generated from the ω-hydroxylation of arachidonic acid (AA) by enzymes of the cytochrome P450 (CYP) family, primarily the CYP4A and CYP4F subfamilies. 20-HETE is most notably identified as a modulator of vascular tone, regulator of renal function, and a contributor to the onset and development of hypertension and cardiovascular disease. 20-HETE-mediated signaling promotes hypertension by sensitizing the vasculature to constrictor stimuli, inducing endothelial dysfunction, and potentiating vascular inflammation. These bioactions are driven by the activation of the G-protein coupled receptor 75 (GPR75), a 20-HETE receptor (20HR). Given the capacity of 20-HETE signaling to drive pro-hypertensive mechanisms, the CYP/20-HETE/GPR75 axis has the potential to be a significant therapeutic target for the treatment of hypertension and cardiovascular diseases associated with increases in blood pressure. In this chapter, we review 20-HETE-mediated cellular mechanisms that promote hypertension, highlight important data in humans such as genetic variants in the CYP genes that potentiate 20-HETE production and describe recent findings in humans with 20HR/GPR75 mutations. Special emphasis is given to the 20HR and respective receptor blockers that have the potential to pave a path to translational and clinical studies for the treatment of 20-HETE-driven hypertension, and obesity/metabolic syndrome.
Sequence-structure based phylogeny of GPCR Class A Rhodopsin receptors
2014, Molecular Phylogenetics and Evolution
Citation Excerpt :
The other receptors Q921A8 MOUSE, Q7TQW1 MOUSE, Q6NWR2 HUMAN/GPR75, Q8BXP3 MOUSE/75, Q6X632 MOUSE/GPR75 and O95800 HUMAN (GPR75) may be distantly related to neuropeptide Y (receptor of neighboring cluster). Our results agree with previous studies where human GPR75 was reported to be closely related to a putative Caenorhabditis elegans neuropeptide Y receptor (24% homology), the rat galanin receptor type 3 (25% homology) and the porcine growth hormone secretagogue receptor type 1b (25% homology) (Tarttelin et al., 1999). RANTES is an inflammatory chemokine belonging to the CC-chemokine subfamily (CCL5) was shown to activate GPR75 (Schall et al., 1988; Ignatov et al., 2006), however, binding could not be established experimentally (Fig. 32).
Current methods of G protein coupled receptors (GPCRs) phylogenetic classification are sequence based and therefore inappropriate for highly divergent sequences, sharing low sequence identity. In this study, sequence structure profile based alignment generated by PROMALS3D was used to understand the GPCR Class A Rhodopsin superfamily evolution using the MEGA 5 software. Phylogenetic analysis included a combination of Neighbor-Joining method and Maximum Likelihood method, with 1000 bootstrap replicates. Our study was able to identify potential ligand association for Class A Orphans and putative/unclassified Class A receptors with no cognate ligand information: GPR21 and GPR52 with fatty acids; GPR75 with Neuropeptide Y; GPR82, GPR18, GPR141 with N-arachidonylglycine; GPR176 with Free fatty acids, GPR10 with Tachykinin & Neuropeptide Y; GPR85 with ATP, ADP & UDP glucose; GPR151 with Galanin; GPR153 and GPR162 with Adrenalin, Noradrenalin; GPR146, GPR139, GPR142 with Neuromedin, Ghrelin, Neuromedin U-25 & Thyrotropin-releasing hormone; GPR171 with ATP, ADP & UDP Glucose; GPR88, GPR135, GPR161, GPR101with 11-cis-retinal; GPR83 with Tackykinin; GPR148 with Prostanoids, GPR109b, GPR81, GPR31with ATP & UTP and GPR150 with GnRH I & GnRHII. Furthermore, we suggest that this study would prove useful in re-classification of receptors, selecting templates for homology modeling and identifying ligands which may show cross reactivity with other GPCRs as signaling via multiple ligands play a significant role in disease modulation.
Cellular and Molecular Biology of Orphan G Protein-Coupled Receptors
2006, International Review of Cytology
Citation Excerpt :
Rather, GPR40 has homology with GPR43, the thrombin receptor precursor (ThrbRP), purinergic P2RY6, and the interleukin (IL)‐8A receptor (Sawzdargo et al., 1997). GPR41 exhibits homology to GPR23, GPR17, and F2RL1 (PAR2) (Sawzdargo et al., 1997), GPR75 has homology with the galanin and ghrelin receptors (Tarttelin et al., 1999), and GPR84 (EX33 or GPCR4), GPR135, and GPR141 have limited sequence identity with known receptors (Fredriksson et al., 2003b; Yousefi et al., 2001). The orphan, GPR176, is not closely related to any receptors in the GPCR superfamily (Hata et al., 1995).
The superfamily of G protein‐coupled receptors (GPCRs) is the largest and most diverse group of membrane‐spanning proteins. It plays a variety of roles in pathophysiological processes by transmitting extracellular signals to cells via heterotrimeric G proteins. Completion of the human genome project revealed the presence of ∼168 genes encoding established nonsensory GPCRs, as well as 207 genes predicted to encode novel GPCRs for which the natural ligands remained to be identified, the so‐called orphan GPCRs. Eighty‐six of these orphans have now been paired to novel or previously known molecules, and 121 remain to be deorphaned. A better understanding of the GPCR structures and classification; knowledge of the receptor activation mechanism, either dependent on or independent of an agonist; increased understanding of the control of GPCR‐mediated signal transduction; and development of appropriate ligand screening systems may improve the probability of discovering novel ligands for the remaining orphan GPCRs.
Gene structure and tissue expression of human selenoprotein W, SEPW1, and identification of a retroprocessed pseudogene, SEPW1P
2003, Biochimica et Biophysica Acta - Gene Structure and Expression
We have determined that the human SEPW1 (selenoprotein W) gene maps to chromosome 19q13.3, spans approximately 6.3 kb and comprises six exons, in contrast to the previously published five exons. The gene lacks canonical TATA and CAAT boxes, but has numerous Sp1 consensus binding sites upstream of multiple transcription start sites. SEPW1 is expressed in all of the 22 tissues assayed, and shows highest expression in skeletal muscle and heart. Additionally, we have also identified a retroprocessed SEPW1 pseudogene, SEPW1P, which maps to chromosome 1p34–35.

View all citing articles on Scopus

^☆: The sequence data reported in this paper have been submitted to GenBank and have been assigned the accession numbers AF072693 (IMAGE clone 222124 sequence) and AF101472 (genomic sequence).

¹: Correspondence to: Section of Molecular Genetics, Division of Biomedical Sciences, Imperial College School of Medicine, Sir Alexander Fleming Building, South Kensington, London, SW7 2AZ. UK. Fax: +44-(0)171-594-3100. E-mail: [email protected].

View full text

Regular ArticleCloning and Characterization of a Novel Orphan G-Protein-Coupled Receptor Localized to Human Chromosome 2p16☆

Abstract

Cell

Progress in Retinal and Eye Research

Genomics

Neurosci. Lett.

Ann. Rev. Biochem.

Hum. Mol. Genet.

Hum. Genet.

Nuc. Acids Res.

Regular Article
Cloning and Characterization of a Novel Orphan G-Protein-Coupled Receptor Localized to Human Chromosome 2p16☆