Rhodopsin-like receptors are a

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respon ...

s that comprise the largest group of

G protein-coupled receptor G protein-coupled receptors (GPCRs), also known as seven-(pass)-transmembrane domain receptors, 7TM receptors, heptahelical receptors, serpentine receptors, and G protein-linked receptors (GPLR), form a large group of evolutionarily-related p ...

Scope

G-protein-coupled receptors, GPCRs, constitute a vast protein family that encompasses a wide range of functions (including various autocrine, paracrine, and endocrine processes). They show considerable diversity at the sequence level, on the basis of which they can be separated into distinct groups. GPCRs are usually described as "superfamily" because they embrace a group of families for which there are indications of evolutionary relationship, but between which there is no statistically significant similarity in sequence. The currently known superfamily members include the rhodopsin-like GPCRs (this family), the

secretin-like GPCR Secretin family receptor proteins, also known as Family B or family 2 of G-protein coupled receptors are regulated by peptide hormones from the glucagon hormone family. The family is different from adhesion G protein-coupled receptors. The secr ...

s, the

cAMP receptors Cyclic AMP receptors from slime molds are a distinct family of G-protein coupled receptors. These receptors control development in Dictyostelium discoideum. In ''D. discoideum'', the cyclic AMP receptors coordinate aggregation of individual ce ...

, the fungal mating pheromone receptors, and the metabotropic glutamate receptor family. There is a specialised database for GPCRs.

Function

The rhodopsin-like GPCRs themselves represent a widespread protein family that includes hormone, neuropeptide, neurotransmitter, and light receptors, all of which transduce extracellular signals through interaction with guanine nucleotide-binding (G) proteins. Although their activating ligands vary widely in structure and character, the amino acid sequences of the receptors are very similar and are believed to adopt a common structural framework comprising 7 transmembrane (TM) helices.

Classes

Rhodopsin-like GPCRs have been classified into the following 19 subgroups (A1-A19) based on a phylogenetic analysis.

Subfamily A1

Chemokine receptor Chemokine receptors are cytokine receptors found on the surface of certain cells that interact with a type of cytokine called a chemokine. There have been 20 distinct chemokine receptors discovered in humans. Each has a rhodopsin-like 7- tr ...

** Chemokine (C-C motif) receptor 1 (, CKR1) ** Chemokine (C-C motif) receptor 2 (, CKR2) ** Chemokine (C-C motif) receptor 3 (, CKR3) ** Chemokine (C-C motif) receptor 4 (, CKR4) ** Chemokine (C-C motif) receptor 5 (, CKR5) ** Chemokine (C-C motif) receptor 8 (, CKR8) ** Chemokine (C-C motif) receptor-like 2 (, CKRX) * chemokine (C motif) receptor 1 (, CXC1) * chemokine (C-X3-C motif) receptor 1 (, C3X1) *

GPR137B G protein-coupled receptor 137B also known as GPR137B is a G protein-coupled receptor which in humans is encoded by the ''GPR137B'' gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendel ...

(, TM7SF1)

Subfamily A2

** Chemokine (C-C motif) receptor-like 1 (, CCR11) ** Chemokine (C-C motif) receptor 6 (, CKR6) ** Chemokine (C-C motif) receptor 7 (, CKR7) ** Chemokine (C-C motif) receptor 9 (, CKR9) ** Chemokine (C-C motif) receptor 10 (, CKRA) * CXC chemokine receptors ** Chemokine (C-X-C motif) receptor 3 () ** Chemokine (C-X-C motif) receptor 4 (, Fusin) ** Chemokine (C-X-C motif) receptor 5 () ** Chemokine (C-X-C motif) receptor 6 (, BONZO) ** Chemokine (C-X-C motif) receptor 7 (, RDC1) * Interleukin-8 (IL8R) ** IL8R-α (, CXCR1) ** IL8R-β (, CXCR2) *

Adrenomedullin receptor Calcitonin receptor-like (CALCRL), also known as the calcitonin receptor-like receptor (CRLR), is a human protein; it is a receptor for calcitonin gene-related peptide. Function The protein encoded by the CALCRL gene is a G protein-coupled ...

() * Duffy blood group, chemokine receptor (, DUFF) * G Protein-coupled Receptor 30 (, CML2, GPCR estrogen receptor)

Subfamily A3

Angiotensin II receptor The angiotensin II receptors, (ATR1) and (ATR2), are a class of G protein-coupled receptors with angiotensin II as their ligands. They are important in the renin–angiotensin system: they are responsible for the signal transduction of the vasoco ...

** Angiotensin II receptor, type 1 (, AG2S) ** Angiotensin II receptor, type 2 (, AG22) ** Apelin receptor (, APJ) * Bradykinin receptor ** Bradykinin receptor B1 (, BRB1) ** Bradykinin receptor B2 (, BRB2) *

GPR15 G protein-coupled receptor 15 is a protein that in humans is encoded by the GPR15 gene. GPR15 is a class A orphan G protein-coupled receptor (heterotrimeric guanine nucleotide-binding protein, GPCR). The ''GPR15'' gene is localized at chromosome ...

(, GPRF) *

GPR25 Probable G-protein coupled receptor 25 is a protein that in humans is encoded by the ''GPR25'' gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''ge ...

()

Subfamily A4

Opioid receptor Opioid receptors are a group of inhibitory G protein-coupled receptors with opioids as ligands. The endogenous opioids are dynorphins, enkephalins, endorphins, endomorphins and nociceptin. The opioid receptors are ~40% identical to somatosta ...

delta Opioid receptor Delta commonly refers to: * Delta (letter) (Δ or δ), a letter of the Greek alphabet * River delta, at a river mouth * D ( NATO phonetic alphabet: "Delta") * Delta Air Lines, US * Delta variant of SARS-CoV-2 that causes COVID-19 Delta may als ...

(, OPRD) **

kappa Opioid receptor Kappa (uppercase Κ, lowercase κ or cursive ; el, κάππα, ''káppa'') is the 10th letter of the Greek alphabet, representing the voiceless velar plosive sound in Ancient and Modern Greek. In the system of Greek numerals, has a value ...

(, OPRK) ** mu Opioid receptor (, OPRM) ** Nociceptin receptor (, OPRX) * Somatostatin receptor ** Somatostatin receptor 1 (, SSR1) ** Somatostatin receptor 2 (, SSR2) ** Somatostatin receptor 3 (, SSR3) ** Somatostatin receptor 4 (, SSR4) ** Somatostatin receptor 5 (, SSR5) *

GPCR neuropeptide receptor GPCR neuropeptide receptors are G-protein coupled receptors which bind various neuropeptides. Members include: * Neuropeptide B/W receptor ** NPBWR1 ** NPBWR2 * Neuropeptide FF receptor ** NPFFR1 ** NPFFR2 * Neuropeptide S receptor ** NPSR1 ...

Neuropeptides B/W receptor 1 Neuropeptides B/W receptor 1, also known as NPBW1 and GPR7, is a human protein encoded by the NPBWR1 gene. As implied by its name, it and related gene NPBW2 (with which it shares 70% nucleotide identity) are transmembranes protein that bind Neur ...

(, GPR7) **

Neuropeptides B/W receptor 2 Neuropeptides B/W receptor 2, also known as NPBW2, is a human protein encoded by the NPBWR2 gene. The protein encoded by this gene is an integral membrane protein and G protein-coupled receptor. The encoded protein is similar in sequence to anothe ...

(, GPR8) * GPR1 orphan receptor ()

Subfamily A5

* Galanin receptor ** Galanin receptor 1 (, GALR) ** Galanin receptor 2 (, GALS) ** Galanin receptor 3 (, GALT) * Cysteinyl leukotriene receptor ** Cysteinyl leukotriene receptor 1 () **

Cysteinyl leukotriene receptor 2 Cysteinyl leukotriene receptor 2, also termed CYSLTR2, is a receptor for cysteinyl leukotrienes (LT) (see leukotrienes#Cysteinyl leukotrienes). CYSLTR2, by binding these cysteinyl LTs (CysLTs; viz, LTC4, LTD4, and to a much lesser extent, LT ...

() * Leukotriene B4 receptor ** Leukotriene B4 receptor (, P2Y7) ** Leukotriene B4 receptor 2 () *

Relaxin receptor The relaxin receptors are a subclass of four closely related G protein-coupled receptors (GPCR) that bind relaxin peptide hormones. Below is list of human relaxin receptors, their endogenous peptide hormones, and what downstream enzymes are ac ...

Relaxin/insulin-like family peptide receptor 1 Relaxin/insulin-like family peptide receptor 1, also known as RXFP1, is a human G protein coupled receptor that is one of the relaxin receptors. It is a rhodopsin-like GPCR which is unusual in this class as it contains a large extracellular bindin ...

(, LGR7) **

Relaxin/insulin-like family peptide receptor 2 Relaxin/insulin-like family peptide receptor 2, also known as RXFP2, is a human G-protein coupled receptor. The receptors for glycoprotein hormones such as follicle-stimulating hormone (FSH; see MIM 136530) and thyroid-stimulating hormone (TSH; s ...

(, GPR106) ** Relaxin/insulin-like family peptide receptor 3 (, SALPR) ** Relaxin/insulin-like family peptide receptor 4 (, GPR100/GPR142) * KiSS1-derived peptide receptor (GPR54) () *

Melanin-concentrating hormone receptor 1 Melanin-concentrating hormone receptor 1, also known as MCH1, is one of the melanin-concentrating hormone receptors found in all mammals. The protein encoded by this gene, a member of the G protein-coupled receptor family 1, is an integral plasma ...

(, GPRO) * Urotensin-II receptor (, UR2R)

Subfamily A6

* Cholecystokinin receptor ** Cholecystokinin A receptor (, CCKR) ** Cholecystokinin B receptor (, GASR) *

Neuropeptide FF receptor The neuropeptide FF receptors are members of the G-protein coupled receptor superfamily of integral membrane proteins which bind the pain modulatory neuropeptides AF and FF. The Neuropeptide FF receptor family is a member of the G protein-coupled ...

Neuropeptide FF receptor 1 Neuropeptide FF receptor 1, also known as NPFF1 is a human protein, encoded by the NPFFR1 gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''genera ...

(, FF1R) **

Neuropeptide FF receptor 2 Neuropeptide FF receptor 2, also known as NPFF2 is a human protein encoded by the NPFFR2 gene. See also * Neuropeptide FF receptor The neuropeptide FF receptors are members of the G-protein coupled receptor superfamily of integral membrane prot ...

(, FF2R) * Orexin receptor ** Hypocretin (orexin) receptor 1 (, OX1R) ** Hypocretin (orexin) receptor 2 (, OX2R) * Vasopressin receptor ** Arginine vasopressin receptor 1A (, V1AR) ** Arginine vasopressin receptor 1B (, V1BR) ** Arginine vasopressin receptor 2 (, V2R) ** Oxytocin receptor () * Gonadotropin releasing hormone receptor (, GRHR) * Pyroglutamylated RFamide peptide receptor (, GPR103) *

GPR22 Probable G-protein coupled receptor 22 is a protein that in humans is encoded by the ''GPR22'' gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''ge ...

(, GPRM) *

GPR176 Probable G-protein coupled receptor 176 is a protein that in humans is encoded by the ''GPR176'' gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning '' ...

(, GPR)

Subfamily A7

* Bombesin receptor **

Bombesin-like receptor 3 The bombesin receptor subtype 3 also known as BRS-3 or BB3 is a protein which in humans is encoded by the ''BRS3'' gene. Function Mammalian bombesin-like peptides are widely distributed in the central nervous system as well as in the gastroin ...

() **

Neuromedin B receptor The neuromedin B receptor (NMBR), now known as BB1 is a G protein-coupled receptor whose endogenous ligand is neuromedin B. In humans, this protein is encoded by the ''NMBR'' gene. Neuromedin B receptor binds neuromedin B, a potent mitogen and ...

() **

Gastrin-releasing peptide receptor The gastrin-releasing peptide receptor (GRPR), now properly known as BB2 is a G protein-coupled receptor whose endogenous ligand is gastrin releasing peptide. In humans it is highly expressed in the pancreas and is also expressed in the stoma ...

() * Endothelin receptor ** Endothelin receptor type A (, ET1R) ** Endothelin receptor type B (, ETBR) ** GPR37 (, ETBR-LP2) *

Neuromedin U receptor The neuromedin U receptors are two G-protein coupled receptor G protein-coupled receptors (GPCRs), also known as seven-(pass)-transmembrane domain receptors, 7TM receptors, heptahelical receptors, serpentine receptors, and G protein-linked ...

Neuromedin U receptor 1 Neuromedin-U receptor 1 is a protein that in humans is encoded by the ''NMUR1'' gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ...

() **

Neuromedin U receptor 2 Neuromedin-U receptor 2 is a protein that in humans is encoded by the ''NMUR2'' gene. Ligands Agonists * synephrine Synephrine, or, more specifically, ''p''-synephrine, is an alkaloid, occurring naturally in some plants and animals, and also ...

() *

Neurotensin receptor Neurotensin receptors are transmembrane receptors that bind the neurotransmitter A neurotransmitter is a signaling molecule secreted by a neuron to affect another cell across a synapse. The cell receiving the signal, any main body part or t ...

** Neurotensin receptor 1 (, NTR1) ** Neurotensin receptor 2 (, NTR2) *

Thyrotropin-releasing hormone receptor Thyrotropin-releasing hormone receptor (TRHR) is a G protein-coupled receptor which binds thyrotropin-releasing hormone. The TRHR is found on the cell membrane of thyrotropes of the anterior pituitary. When the TRHR binds TRH it activates phosph ...

(, TRFR) * Growth hormone secretagogue receptor () * GPR39 () *

Motilin receptor Motilin receptor is a G protein-coupled receptor that binds motilin. Motilin in turn is an intestinal peptide Peptides (, ) are short chains of amino acids linked by peptide bonds. Long chains of amino acids are called proteins. Chains of fe ...

(, GPR38)

Subfamily A8

* Anaphylatoxin receptors ** C3a receptor (, C3AR) ** C5a receptor (, C5AR) ** Chemokine-like receptor 1 (, CML1) *

Formyl peptide receptor The formyl peptide receptors (FPR) belong to a class of G protein-coupled receptors involved in chemotaxis. In humans, there are three formyl peptide receptor isoforms, each encoded by a separate gene that are named FPR1, FPR2, and FPR3. T ...

Formyl peptide receptor 1 Formyl peptide receptor 1 (FPR1, FPR1 receptor, fMet-Leu-Phe receptor 1, FMLP receptor 1, or N-formylmethionyl-leucyl-phenylalanine receptor 1) is a cell surface receptor protein that in humans is encoded by the ''formyl peptide receptor 1'' (' ...

(, FMLR) ** Formyl peptide receptor-like 1 (, FML2) **

Formyl peptide receptor-like 2 N-formyl peptide receptor 3 (FPR3) is a receptor protein that in humans is encoded by the ''FPR3'' gene. Nomenclature note Confusingly, there are two nomenclatures for FPR receptors and their genes, the first one used, FPR, FPR1, and FPR2 and i ...

(, FML1) * MAS1 oncogene ** MAS1 (, MAS) **

MAS1L Mas-related G-protein coupled receptor MRG is a protein that in humans is encoded by the ''MAS1L'' gene. See also * MAS1 oncogene The MAS1 oncogene (MAS receptor) is a G protein-coupled receptor which binds the angiotensin II metabolite angio ...

(, MRG) * GPR1 () * GPR32 (, GPRW) *

GPR44 Prostaglandin D2 receptor 2 (DP2 or CRTH2) is a human protein encoded by the PTGDR2 gene and GPR44. DP2 has also been designated as CD294 (cluster of differentiation 294). It is a member of the class of prostaglandin receptors which bind with and ...

() *

GPR77 C5a anaphylatoxin chemotactic receptor 2 is a protein that in humans is encoded by the ''C5AR2'' gene. It's a complement component G protein-coupled receptor, of Rhodopsin-like receptors, class A (rhodopsin-like). Function The anaphylatoxins C ...

(, C5L2)

Subfamily A9

* Melatonin receptor ** Melatonin receptor 1A (, ML1A) ** Melatonin receptor 1B (, ML1B) * Neurokinin receptor ** Tachykinin receptor 1 (, NK1R) ** Tachykinin receptor 2 (, NK2R) ** Tachykinin receptor 3 (, NK3R) * Neuropeptide Y receptor ** Neuropeptide Y receptor Y1 (, NY1R) ** Neuropeptide Y receptor Y2 (, NY2R) ** Pancreatic polypeptide receptor 1 (, NY4R) **

Neuropeptide Y receptor Y5 Neuropeptide Y receptor type 5 is a protein that in humans is encoded by the ''NPY5R'' gene. Selective ligands Agonists * Neuropeptide Y (endogenous agonist, non subtype selective) * BWX-46 (selective NPY5 agonist, CAS# 172997-92-1) * Pe ...

(, NY5R) * Prolactin-releasing peptide receptor ( PRLHR, GPRA) *

Prokineticin receptor 1 Prokineticin receptor 1, also known as PKR1, is a human protein encoded by the PROKR1 gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation' ...

(, GPR73) *

Prokineticin receptor 2 Prokineticin receptor 2 (PKR2), is a dimeric G protein-coupled receptor encoded by the PROKR2 gene in humans. Function Prokineticins are secreted proteins that can promote angiogenesis and induce strong gastrointestinal smooth muscle contracti ...

(, PKR2) * GPR19 (, GPRJ) *

GPR50 G protein-coupled receptor 50 is a protein which in humans is encoded by the ''GPR50'' gene. Function GPR50 is a member of the G protein-coupled receptor family of integral membrane proteins and is most closely related to the melatonin receptor ...

(, ML1X) * GPR75 () *

GPR83 Probable G-protein coupled receptor 83 is a protein that in humans is encoded by the ''GPR83'' gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''ge ...

(, GPR72)

Subfamily A10

* Glycoprotein hormone receptor ** FSH-receptor () ** Luteinizing hormone/choriogonadotropin receptor (, LSHR) ** Thyrotropin receptor () * Leucine-rich repeat-containing G protein-coupled receptor 4 (, GPR48) * Leucine-rich repeat-containing G protein-coupled receptor 5 (, GPR49) * Leucine-rich repeat-containing G protein-coupled receptor 6 ()

Subfamily A11

* GPR40-related receptor ** Free fatty acid receptor 1 (, GPR40) **

Free fatty acid receptor 2 Free fatty acid receptor 2 (FFA2) is a G-protein coupled receptor encoded by the ''FFAR2'' gene. Expression ''FFAR2'' mRNA is expressed in adipose tissue, pancreas, spleen, lymph nodes, bone marrow, and peripheral blood mononuclear cells. ''FFAR2 ...

(, GPR43) **

Free fatty acid receptor 3 Free fatty acid receptor 3 (FFA3) is a G-protein coupled receptor that in humans is encoded by the ''FFAR3'' gene. Animal studies Knockout mouse studies have implicated FFAR3 in diabetes, colitis, hypertension and asthma. However, discrepancies ...

(, GPR41) **

GPR42 Putative G-protein coupled receptor 42 (previously termed FFAR1L, FFAR3L, GPR41L, and GPR42P) is a protein that in humans is encoded by the ''GPR42'' gene. The human GPR gene is located at the same site as the human ''FFAR1, FFAR,'' and ''FFAR3'' ...

(, FFAR1L) * P2 purinoceptor ** Purinergic receptor P2Y₁ () ** Purinergic receptor P2Y₂ () ** Purinergic receptor P2Y₄ () ** Purinergic receptor P2Y₆ () ** Purinergic receptor P2Y₈ () ** Purinergic receptor P2Y₁₁ () * Hydroxycarboxylic acid receptor 1 (, GPR81) * Hydroxycarboxylic acid receptor 2, Niacin receptor 1 (, GPR109A) * Hydroxycarboxylic acid receptor 3, Niacin receptor 2 (, GPR109B, HM74) * GPR31 (, GPRV) *

GPR82 Probable G-protein coupled receptor 82 is a protein that in humans is encoded by the ''GPR82'' gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''ge ...

() * Oxoglutarate (alpha-ketoglutarate) receptor 1 (, GPR80) * Succinate receptor 1 (, GPR91)

Subfamily A12

* P2 purinoceptor ** Purinergic receptor P2Y₁₂ () ** Purinergic receptor P2Y₁₃ (, GPR86) ** Purinergic receptor P2Y₁₄ (, UDP-glucose receptor, KI01) *

GPR34 Probable G-protein coupled receptor 34 is a protein that in humans is encoded by the ''GPR34'' gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''g ...

() *

GPR87 Probable G-protein coupled receptor 87 is a protein that in humans is encoded by the ''GPR87'' gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''g ...

() *

GPR171 Probable G-protein coupled receptor 171 is a protein that in humans is encoded by the ''GPR171'' gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ' ...

(, H963) *

Platelet-activating factor receptor The platelet-activating factor receptor (PAF-R) is a G-protein coupled receptor which binds platelet-activating factor. It is encoded in the human by the ''PTAFR'' gene. The PAF receptor shows structural characteristics of the rhodopsin (MIM 180 ...

(, PAFR)

Subfamily A13

Cannabinoid receptor Cannabinoid receptors, located throughout the body, are part of the endocannabinoid system a class of cell membrane receptors in the G protein-coupled receptor superfamily. As is typical of G protein-coupled receptors, the cannabinoid recep ...

Cannabinoid receptor 1 (brain) Cannabinoid receptor type 1 (CB1), also known as cannabinoid receptor 1, is a G protein-coupled cannabinoid receptor that in humans is encoded by the ''CNR1'' gene. The human CB1 receptor is expressed in the peripheral nervous system and centr ...

(, CB1R) ** Cannabinoid receptor 2 (macrophage) (, CB2R) * Lysophosphatidic acid receptor ** Lysophosphatidic acid receptor 1 () ** Lysophosphatidic acid receptor 2 () ** Lysophosphatidic acid receptor 3 () * Sphingosine 1-phosphate receptor ** Sphingosine 1-phosphate receptor 1 () ** Sphingosine 1-phosphate receptor 2 () ** Sphingosine 1-phosphate receptor 3 () ** Sphingosine 1-phosphate receptor 4 () ** Sphingosine 1-phosphate receptor 5 () * Melanocortin/ACTH receptor ** Melanocortin 1 receptor (, MSHR) ** Melanocortin 3 receptor () ** Melanocortin 4 receptor () ** Melanocortin 5 receptor () ** ACTH receptor (), ACTR) * GPR3 () * GPR6 () * GPR12 (, GPRC)

Subfamily A14

Eicosanoid receptor Most of the eicosanoid receptors are integral membrane protein G protein-coupled receptors (GPCRs) that bind and respond to eicosanoid signaling molecules. Eicosanoids are rapidly metabolized to inactive products and therefore are short-lived. A ...

** Prostaglandin D₂ receptor (, PD2R) ** Prostaglandin E₁ receptor (, PE21) ** Prostaglandin E₂ receptor (, PE22) ** Prostaglandin E₃ receptor (, PE23) ** Prostaglandin E₄ receptor (, PE24) ** Prostaglandin F receptor (, PF2R) ** Prostaglandin I₂ (prostacyclin) receptor (, PI2R) ** Thromboxane A₂ receptor (, TA2R)

Subfamily A15

* Lysophosphatidic acid receptor ** Lysophosphatidic acid receptor 4 () ** Lysophosphatidic acid receptor 5 () ** Lysophosphatidic acid receptor 6 () * P2 purinoceptor ** Purinergic receptor P2Y₁₀ (, P2Y10) * Protease-activated receptor ** Coagulation factor II (thrombin) receptor-like 1 (, PAR2) ** Coagulation factor II (thrombin) receptor-like 2 (, PAR3) ** Coagulation factor II (thrombin) receptor-like 3 (, PAR4) * Epstein-Barr virus induced gene 2 (lymphocyte-specific G protein-coupled receptor) () *

Proton-sensing G protein-coupled receptors Proton-sensing G protein-coupled receptors are transmembrane receptors which sense acidic pH and include GPR132 (G2A), GPR4, GPR68 (OGR1) and GPR65 (TDAG8). These G protein-coupled receptors are activated when extracellular pH falls into the rang ...

** GPR4 () ** GPR65 () **

GPR68 Ovarian cancer G-protein coupled receptor 1 is a protein that in humans is encoded by the ''GPR68'' gene. See also *Proton-sensing G protein-coupled receptors Proton-sensing G protein-coupled receptors are transmembrane receptors which sense ac ...

() ** GPR132 (, G2A) *

GPR17 Uracil nucleotide/cysteinyl leukotriene receptor is a G protein-coupled receptor that in humans is encoded by the ''GPR17'' gene located on chromosome 2 at position q21. The actual activating ligands for and some functions of this receptor are d ...

(, GPRH) * GPR18 (, GPRI) *

GPR20 Probable G-protein coupled receptor 20 is a protein that in humans is encoded by the ''GPR20'' gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''g ...

(, GPRK) *

GPR35 G protein-coupled receptor 35 also known as GPR35 is a G protein-coupled receptor which in humans is encoded by the ''GPR35'' gene. Heightened expression of GPR35 is found in immune and gastrointestinal tissues, including the crypts of Lieberküh ...

() * GPR55 () * Coagulation factor II receptor (, THRR)

Subfamily A16

Opsin 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 pro ...

s **

Rhodopsin Rhodopsin, also known as visual purple, is a protein encoded by the RHO gene and a G-protein-coupled receptor (GPCR). It is the opsin of the rod cells in the retina and a light-sensitive receptor protein that triggers visual phototransduct ...

(, OPSD) ** Opsin 1 (cone pigments), short-wave-sensitive (color blindness, tritan) (, OPSB) (blue-sensitive opsin) ** Opsin 1 (cone pigments), medium-wave-sensitive (color blindness, deutan) (, OPSG) (green-sensitive opsin) ** Opsin 1 (cone pigments), long-wave-sensitive (color blindness, protan) (, OPSR) (red-sensitive opsin) ** Opsin 3, Panopsin () ** Opsin 4, Melanopsin () ** Opsin 5 (, GPR136) ** Retinal G protein coupled receptor () ** Retinal pigment epithelium-derived rhodopsin homolog (, OPSX) (visual pigment-like receptor opsin)

Subfamily A17

* 5-Hydroxytryptamine (5-HT) receptor ** 5-HT_2A (, 5H2A) ** 5-HT_2B (, 5H2B) ** 5-HT_2C (, 5H2C) ** 5-HT₆ (, 5H6) *

Adrenergic receptor The adrenergic receptors or adrenoceptors are a class of G protein-coupled receptors that are targets of many catecholamines like norepinephrine (noradrenaline) and epinephrine (adrenaline) produced by the body, but also many medications like beta ...

** Alpha_1A (, A1AA) ** Alpha_1B (, A1AB) ** Alpha_1D (, A1AD) ** Alpha_2A (, A2AA) ** Alpha_2B (, A2AB) ** Alpha_2C (, A2AC) ** Beta₁ (, B1AR) ** Beta₂ (, B2AR) ** Beta₃ (, B3AR) *

Dopamine receptor Dopamine receptors are a class of G protein-coupled receptors that are prominent in the vertebrate central nervous system (CNS). Dopamine receptors activate different effectors through not only G-protein coupling, but also signaling through diffe ...

** D₁ (, DADR) ** D₂ (, D2DR) ** D₃ (, D3DR) ** D₄ (, D4DR) ** D₅ (, DBDR) *

Trace amine receptor Trace amine-associated receptors (TAARs), sometimes referred to as trace amine receptors (TAs or TARs), are a class of G protein-coupled receptors that were discovered in 2001. TAAR1, the first of six functional human TAARs, has gained considerab ...

** TAAR1 (, TAR1) ** TAAR2 (, GPR58) **

TAAR3 Putative trace amine-associated receptor 3 (TAAR3) is a human pseudogene Pseudogenes are nonfunctional segments of DNA that resemble functional genes. Most arise as superfluous copies of functional genes, either directly by DNA duplication or ...

(, GPR57) ** TAAR5 (, PNR) ** TAAR6 (, TAR4) ** TAAR8 (, GPR102) ** TAAR9 (, TAR3) * Histamine H₂ receptor (, HH2R)

Subfamily A18

* Histamine H₁ receptor (, HH1R) * Histamine H₃ receptor () * Histamine H₄ receptor () *

Adenosine receptor The adenosine receptors (or P1 receptors) are a class of purinergic G protein-coupled receptors with adenosine as the endogenous ligand. There are four known types of adenosine receptors in humans: A1, A2A, A2B and A3; each is encoded by a dif ...

** A₁ (, AA1R) ** A_2a (, AA2A) ** A_2b (, AA2B) ** A₃ (, AA3R) *

Muscarinic acetylcholine receptor Muscarinic acetylcholine receptors, or mAChRs, are acetylcholine receptors that form G protein-coupled receptor, G protein-coupled receptor complexes in the cell membranes of certain neurons and other Cell (biology), cells. They play several r ...

** M₁ (, ACM1) ** M₂ (, ACM2) ** M₃ (, ACM3) ** M₄ (, ACM4) ** M₅ (, ACM5) *

GPR21 Probable G-protein coupled receptor 21 is a protein that in humans is encoded by the ''GPR21'' gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''g ...

(, GPRL) *

GPR27 Probable G-protein coupled receptor 27 is a protein that in humans is encoded by the ''GPR27'' gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''ge ...

() *

GPR45 Probable G-protein coupled receptor 45 is a protein that in humans is encoded by the ''GPR45'' gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''g ...

(, PSP24) *

GPR52 Probable G-protein coupled receptor 52 is a protein that in humans is encoded by the ''GPR52'' gene. Members of the G protein-coupled receptor (GPR) family play important roles in signal transduction from the external environment to the inside of ...

() *

GPR61 Probable G-protein coupled receptor 61 is a protein that in humans is encoded by the ''GPR61'' gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''g ...

() * GPR62 () *

GPR63 Probable G-protein coupled receptor 63 is a protein that in humans is encoded by the ''GPR63'' gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''g ...

() * GPR78 () *

GPR84 Probable G-protein coupled receptor 84 is a protein that in humans is encoded by the ''GPR84'' gene. Discovery GPR84 (EX33) was described practically in the same time by two groups. One was the group of Timo Wittenberger in the Zentrum fur Mole ...

() *

GPR85 Probable G-protein coupled receptor 85 is a protein that in humans is encoded by the ''GPR85'' gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''ge ...

() *

GPR88 Probable G-protein coupled receptor 88 is a protein that in humans is encoded by the ''GPR88'' gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''ge ...

() *

GPR101 Probable G-protein coupled receptor 101 is a protein that in humans is encoded by the ''GPR101'' gene. G protein-coupled receptors (GPCRs, or GPRs) contain 7 transmembrane domains and transduce extracellular signals through heterotrimeric G prote ...

() *

GPR161 G-protein coupled receptor 161 is a protein that in humans is encoded by the ''GPR161'' gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generatio ...

(, RE2) *

GPR173 Probable G-protein coupled receptor 173 is a protein that in humans is encoded by the ''GPR173'' gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ' ...

(, SREB3)

Subfamily A19

* 5-Hydroxytryptamine (5-HT) receptor ** 5-HT_1A (, 5H1A) ** 5-HT_1B (, 5H1B) ** 5-HT_1D (, 5H1D) ** 5-HT_1E (, 5H1E) ** 5-HT_1F (, 5H1F) ** 5-HT₄ () ** 5-HT_5A (, 5H5A) ** 5-HT₇ (, 5H7)

Unclassified

Olfactory receptor Olfactory receptors (ORs), also known as odorant receptors, are chemoreceptors expressed in the cell membranes of olfactory receptor neurons and are responsible for the detection of odorants (for example, compounds that have an odor) which give ri ...

Nematode chemoreceptor Nematode chemoreceptors are chemoreceptors of nematodes. Animals recognise a wide variety of chemicals using their senses of taste and smell. The nematode ''Caenorhabditis elegans'' has only 14 types of chemosensory neuron, yet is able to respon ...

(multiple, including ） *

Taste receptor A taste receptor or tastant is a type of cellular receptor which facilitates the sensation of taste. When food or other substances enter the mouth, molecules interact with saliva and are bound to taste receptors in the oral cavity and other loca ...

type 2 *

Vomeronasal receptor Vomeronasal receptors are a class of olfactory receptors that putatively function as receptors for pheromones. Pheromones have evolved in all animal phyla, to signal sex and dominance status, and are responsible for stereotypical social and sexua ...

type 1 **

VN1R1 Vomeronasal type-1 receptor 1 is a protein that in humans is encoded by the ''VN1R1'' gene. Function Pheromones are chemical signals that elicit specific behavioral responses and physiologic alterations in recipients of the same species. The p ...

VN1R2 Vomeronasal type-1 receptor 2 is a protein that in humans is encoded by the ''VN1R2'' gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation' ...

VN1R3 Vomeronasal type-1 receptor 3 is a protein that is encoded by the ''VN1R3'' gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''bir ...

VN1R4 Vomeronasal type-1 receptor 4 is a protein that in humans is encoded by the ''VN1R4'' gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation' ...

VN1R5 Vomeronasal type-1 receptor 5 is a protein that in humans is encoded by the ''VN1R5'' gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation' ...

References

External links

* * This database includes multiple sequence alignments of all GPCR families and sub-families. {{G protein-coupled receptors G protein-coupled receptors Protein domains Protein families