TABLE 1

Class 1 G protein-coupled receptors Family represents the classification of orphan receptors adapted from Vassilatis et al. ( 2003 ). The IUPHAR Receptor Code is described in Humphrey and Barnard ( 1998 ). A representative, but not necessarily complete list of putative endogenous ligands is given. Provisional nomenclature is given in square brackets. NC-IUPHAR does not normally allocate names to receptors where there is only a single publication identifying the putative endogenous ligand. Gene symbol is approved by the HUGO Gene Nomenclature Committee (http://www.gene.ucl.ac.uk/nomenclature/). Gene IDs are from Entrez Gene (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=gene).

Family IUPHAR Receptor Code Ligand Official IUPHAR Nomenclature Human Gene Symbol Human Gene ID Mouse Gene ID Rat Gene ID
5-Hydroxytryptamine 2.1:5HT:1:5HT1A: 5-Hydroxytryptamine 5-HT1A HTR1A 3350 15550 24473
5-Hydroxytryptamine 2.1:5HT:2:5HT1B: 5-Hydroxytryptamine 5-HT1B HTR1B 3351 15551 25075
5-Hydroxytryptamine 2.1:5HT:3:5HT1D: 5-Hydroxytryptamine 5-HT1D HTR1D 3352 15552 25323
5-Hydroxytryptamine 2.1:5HT:4:5HT1E: 5-Hydroxytryptamine 5-HT1e HTR1E 3354
5-Hydroxytryptamine 2.1:5HT:5:5HT1F: 5-Hydroxytryptamine 5-HT1F HTR1F 3355 15557 60448
5-Hydroxytryptamine 2.1:5HT:6:5HT2A: 5-Hydroxytryptamine 5-HT2A HTR2A 3356 15558 29595
5-Hydroxytryptamine 2.1:5HT:7:5HT2B: 5-Hydroxytryptamine 5-HT2B HTR2B 3357 15559 29581
5-Hydroxytryptamine 2.1:5HT:8:5HT2C: 5-Hydroxytryptamine 5-HT2C HTR2C 3358 15560 25187
5-Hydroxytryptamine 2.1:5HT:9:5HT4: 5-Hydroxytryptamine 5-HT4 HTR4 3360 15562 25324
5-Hydroxytryptamine 5-Hydroxytryptamine 5-HT5A HTR5A 3361 15563 25689
5-Hydroxytryptamine 2.1:5HT:10:5HT6: 5-Hydroxytryptamine 5-HT6 HTR6 3362 15565 64354
5-Hydroxytryptamine 2.1:5HT:11:5HT7: 5-Hydroxytryptamine 5-HT7 HTR7 3363 15566 65032
Acetylcholine (muscarinic) 2.1:ACH:1:M1A: Acetylcholine M1 CHRM1 1128 12669 25229
Acetylcholine (muscarinic) 2.1:ACH:2:M2A: Acetylcholine M2 CHRM2 1129 107850 81645
Acetylcholine (muscarinic) 2.1:ACH:4:M2B: Acetylcholine M3 CHRM4 1132 12672 25111
Acetylcholine (muscarinic) 2.1:ACH:3:M1B: Acetylcholine M4 CHRM3 1131 12671 24260
Acetylcholine (muscarinic) 2.1:ACH:5:M1C: Acetylcholine M5 CHRM5 1133 12673 53949
Adenosine 2.1:ADO:1:A1: Adenosine A1 ADORA1 134 11539 29290
Adenosine 2.1:ADO:2:A2A: Adenosine A2A ADORA2A 135 11540 25369
Adenosine 2.1:ADO:3:A2B: Adenosine A2B ADORA2B 136 11541 29316
Adenosine 2.1:ADO:4:A3: Adenosine A3 ADORA3 140 11542 25370
Adrenoceptors 2.1:ADR:1:A1A: Noradrenaline α1A ADRA1A 148 11549 29412
Adrenoceptors 2.1:ADR:2:A1B: Adrenaline α1B ADRA1B 147 11548 24173
Adrenoceptors 2.1:ADR:3:A1D: Adrenaline α1D ADRA1D 146 11550 29413
Adrenoceptors 2.1:ADR:4:A2A: Adrenaline α2A ADRA2A 150 11551 25083
Adrenoceptors 2.1:ADR:5:A2B: Adrenaline α2B ADRA2B 151 11552 24174
Adrenoceptors 2.1:ADR:6:A2C: Adrenaline α2c ADRA2C 152 11553 24175
Adrenoceptors 2.1:ADR:7:B1: Noradrenaline β1 ADRB1 153 11554 24925
Adrenoceptors 2.1:ADR:8:B2: Adrenaline β2 ADRB2 154 11555 24176
Adrenoceptors 2.1:ADR:9:B3: Adrenaline β3 ADRB3 155 11556 25645
Anaphylatoxin Anaphylatoxin C5a, C5a des Arg74 GPR77 27202 319430 445269
Anaphylatoxin Anaphylatoxin C5a C5R1 728 12273 113959
Anaphylatoxin Anaphylatoxin C3a C3AR1 719 12267 84007
Angiotensin 2.1:ANG:1:AT1: Angiotensin AT1 AGTR1 185 11607 81638
Angiotensin 2.1:ANG:2:AT2: Angiotensin AT2 AGTR2 186 11609 24182
Apelin 2.1:APJ:1:APJ: Apelin AGTRL1 187 23796 83518
Bombesin 2.1:BB:1:BB1: Neuromedin B BB1 NMBR 4829 18101 25264
Bombesin 2.1:BB:2:BB2: Gastrin-releasing peptide BB2 GRPR 2925 14829 24938
Bombesin 2.1:BB:3:BB3: BB3 BRS3 680 12209 260319
Bradykinin 2.1:BK:1:B1: Bradykinin B1 BDKRB1 623 12061 81509
Bradykinin 2.1:BK:2:B2: Bradykinin B2 BDKRB2 624 12062 25245
Cannabinoid 2.1:CB:1:CB1: Cannabinoid CB1 CNR1 1268 12801 25248
Cannabinoid 2.1:CB:2:CB2: Cannabinoid CB2 CNR2 1269 12802 57302
Chemokine 2.1:CHK:1:CXC1: CXCL8 CXCR1 IL8RA 3577 227288 54258
Chemokine 2.1:CHK:2:CXC2: CXCL1—3, CXCL5—8 CXCR2 IL8RB 3579 12765 29385
Chemokine 2.1:CHK:3:CXC3: CXCL9—11 CXCR3 CXCR3 2833 12766 84475
Chemokine 2.1:CHK:4:CXC4: CXCL12 CXCR4 CXCR4 7852 12767 60628
Chemokine 2.1:CHK:5:CXC5: CXCL13 CXCR5 BLR1 643 12145 29363
Chemokine 2.1:CHK:6:CC1: CCL3, CCL5, CCL7, CCL8, CCL13—16, CCL23 CCR1 CCR1 1230 12768 57301
Chemokine 2.1:CHK:7:CC2: CCL2, CCL7, CCL8, CCL13 CCR2 CCR2 1231 12772 60463
Chemokine 2.1:CHK:8:CC3: CCL11 (eotaxin); CCL5, CCL7, CCL8, CCL13, CCL15, CCL24, CCL26 CCR3 CCR3 1232 12771 117027
Chemokine 2.1:CHK:9:CC4: CCL17, CCL22 CCR4 CCR4 1233 12773 171054
Chemokine 2.1:CHK:10:CC5: CCL3, CCL4, CCL5, CCL8, CCL14 CCR5 CCR5 1234 12774 117029
Chemokine 2.1:CHK:11:CC6: CCL20 CCR6 CCR6 1235 12458
Chemokine 2.1:CHK:12:CC7: CCL19, CCL21 CCR7 CCR7 1236 12775 287673
Chemokine 2.1:CHK:13:CC8: CCL1, CCL4, CCL17 CCR8 CCR8 1237 12776
Chemokine 2.1:CHK:14:CC9: CCL25 CCR9 CCR9 10803 12769 282832
Chemokine 2.1:CHK:15:CC10: CCL26—28 CCR10 CCR10 2826 12777 363682
Chemokine 2.1:CHK:17:CX3C1: CX3CL1 CX3CR1 CX3CR1 1524 13051 171056
Chemokine 2.1:CHK:18:XC1: XCL1, XCL2 XCR1 XCR1 2829 23832 301086
Chemokine 2.1:CHK:19:CXC6: CXCL16 CXCR6 10663 80901
Cholecystokinin 2.1:CCK:1:CCK1: Cholecystokinin CCK1 CCKAR 886 12425 24889
Cholecystokinin 2.1:CCK:2:CCK2: Cholecystokinin, gastrin CCK2 CCKBR 887 12426 25706
Dopamine 2.1:DA:1:D1A: Dopamine D1 DRD1 1812 13488 25678
Dopamine 2.1:DA:2:D2A: Dopamine D2 DRD2 1813 13489 24318
Dopamine 2.1:DA:3:D2B: Dopamine D3 DRD3 1814 13490 29238
Dopamine 2.1:DA:4:D2C: Dopamine D4 DRD4 1815 13491 25432
Dopamine 2.1:DA:5:D1B: Dopamine D5 DRD5 1816 13492 25195
Endothelin 2.1:ET:1:ETA: Endothelin 1, endothelin 2 ETA EDNRA 1909 13617 24326
Endothelin 2.1:ET:2:ETB: Endothelins 1, 2 and 3 ETB EDNRB 1910 13618 50672
Free fatty acid 2.1:FFA:3:FFA3 Acetate GPR43 2867 233079 292794
Free fatty acid 2.1:FFA:2:FFA2 Carboxylic acids GPR41 2865 365228
Free fatty acid GPR42a 2866
Free fatty acid 2.1:FFA:1:FFA1 Long chain carboxylic acids GPR40 2864 233081 266607
G protein-coupled bile acid 2.1:BA:1:BA Bile acids GPBAR1 151306 227289
Galanin 2.1:GAL:1:GAL1: Galanin GAL1 GALR1 2587 14427 50577
Galanin 2.1:GAL:2:GAL2: Galanin GAL2 GALR2 8811 14428 29234
Galanin 2.1:GAL:3:GAL3: Galanin GAL3 GALR3 8484 14429 29235
Motilin 2.1:MTLN:1:MTLN Motilin Motilin MLNR 2862
Ghrelin 2.1:GRLN:1:GRLN Ghrelin Ghrelin GHSR 2693 208188 84022
Glycoprotein hormone 2.1:GLYC:3:FSH: Follicle-stimulating hormone FSHR 2492 14309 25449
Glycoprotein hormone 2.1:GLYC:2:LHCG: Luteinizing hormone, chorionic gonadotropin LHCGR 3973 16867 25477
Glycoprotein hormone 2.1:GLYC:1:TSH: Thyroid-stimulating hormone TSHR 7253 22095 25360
GnRH 2.1:GNRH:1:GNRH1: Gonadotrophin-releasing hormone GNRHR 2798 14715 81668
GnRH Gonadotrophin-releasing hormone GNRHR2 114814
Histamine 2.1:HIST:1:H1: Histamine H1 HRH1 3269 15465 24448
Histamine 2.1:HIST:2:H2: Histamine H2 HRH2 3274 15466 25461
Histamine 2.1:HIST:3:H3: Histamine H3 HRH3 11255 99296 85268
Histamine 2.1:HIST:4:H4: Histamine H4 HRH4 59340 225192 170704
KiSS1-derived peptide 2.1:KISS:1:KISS KiSS-1 gene product GPR54 84634 114229 78976
Leukotriene and lipoxin 2.1:LT:1:CLT1: Leukotriene D4 CysLT1 CYSLTR1 10800 58861 114099
Leukotriene and lipoxin 2.1:LT:2:CLT2: Leukotriene C4 CysLT2 CYSLTR2 57105 70086 170926
Leukotriene and lipoxin 2.1:LT:3:BLT1: Leukotriene B4 BLT1 LTB4R 1241 16995 59264
Leukotriene and lipoxin 2.1:LT:4:BLT2: Leukotriene B4 BLT2 LTB4R2 56413 57260 114098
Leukotriene and lipoxin 2.1:LT:5:OXE: 5-Oxo-6,8,11,14-eicosatetraenoic acid OXE OXER1 165140
Leukotriene and lipoxin 2.1:LT:6:ALX: Lipoxin Ab ALX FPRL1 2358 14294 171328
Lysophospholipid 2.1:LPL:LPA1: Lysophosphatidic acid LPA1 EDG2 1902 14745 116744
Lysophospholipid 2.1:LPL:LPA2: Lysophosphatidic acid LPA2 EDG4 9170 53978
Lysophospholipid 2.1:LPL:LPA3: Lysophosphatidic acid LPA3 EDG7 23566 65086 66025
Lysophospholipid 2.1:LPL:SIP1: Sphingosine 1-phosphate S1P1 EDG1 1901 13609 29733
Lysophospholipid 2.1:LPL:SIP2: Sphingosine 1-phosphate S1P2 EDG5 9294 14739 29415
Lysophospholipid 2.1:LPL:S1P3: Sphingosine 1-phosphate S1P3 EDG3 1903 13610 29736
Lysophospholipid 2.1:LPL:SIP4: Sphingosine 1-phosphate S1P4 EDG6 8698 13611 314649
Lysophospholipid 2.1:LPL:SIP5: Sphingosine 1-phosphate S1P5 EDG8 53637 94226 60399
Melanin-concentrating hormone 2.1:MCH:1:MCH1: Melanin-concentrating hormone MCH1 GPR24 2847 207911 83567
Melanin-concentrating hormone 2.1:MCH:2:MCH2: Melanin-concentrating hormone MCH2 GPR145 84539
Melanocortin 2.1:MC:1:MC1: α-Melanocyte stimulating hormone MC1 MC1R 4157 17199 292083
Melanocortin 2.1:MC:2:MC2: Adrenocorticotropic hormone MC2 MC2R 4158 17200 282839
Melanocortin 2.1:MC:3:MC3: γ-Melanocyte stimulating hormone MC3 MC3R 4159 17201 29310
Melanocortin 2.1:MC:4:MC4: β-Melanocyte stimulating hormone MC4 MC4R 4160 17202 25635
Melanocortin 2.1:MC:5:MC5: α-Melanocyte stimulating hormone MC5 MC5R 4161 17203 25726
Melatonin 2.1:MLT:1:MT1: Melatonin [MT1] MTNR1A 4543 17773 114211
Melatonin 2.1:MLT:1:MT2: Melatonin [MT2] MTNR1B 4544 244701 192646
Neuromedin U 2.1:NMU:2:NMU2 Neuromedin U NMU2 NMUR2 56923 216749 64042
Neuromedin U 2.1:NMU:1:NMU1 Neuromedin U NMU1 NMUR1 10316 14767 65276
Neuropeptide FF/neuropeptide AF Neuropeptide FF GPR147 64106 64107
Neuropeptide FF/neuropeptide AF Neuropeptide FF GPR74 10886 104443 78964
Neuropeptide S Neuropeptide S GPR154 387129 319239
Neuropeptide W/neuropeptide B Neuropeptide W, neuropeptide B GPR8 2832
Neuropeptide W/neuropeptide B Neuropeptide W, neuropeptide B GPR7 2831 14769 297795
Neuropeptide Y 2.1:NPY:1:Y1: Neuropeptide Y Y1 NPY1R 4886 18166 29358
Neuropeptide Y 2.1:NPY:2:Y2: Neuropeptide Y Y2 NPY2R 4887 18167 66024
Neuropeptide Y 2.1:NPY:3:Y4: Pancreatic polypeptide Y4 PPYR1 5540 19065 29471
Neuropeptide Y 2.1:NPY:4:Y5: Neuropeptide Y Y5 NPY5R 4889 18168 25340
Neurotensin 2.1:NTSN:1:NTS1: Neurotensin NTS1 NTSR1 4923 18216 366274
Neurotensin 2.1:NTSN:2:NTS2: Neurotensin NTS2 NTSR2 23620 18217 64636
N-Formylpeptide family FPRL2 2359
N-Formylpeptide family N-Formyl-l-Met-l-Leu-l-Phe (fMLP) FPR1 2357 14293
Nicotinic acid GPR81 27198 243270
Nicotinic acid Nicotinic acid (low affinity) GPR109B 8843
Nicotinic acid Nicotinic acid (high affinity) GPR109A 338442 80885 353250
Opioid 2.1:OP:2:DELTA: β-Endorphin δ OPRD1 4985 18386 24613
Opioid 2.1:OP:3:KAPPA: Dynorphin A κ OPRK1 4986 18387 29335
Opioid 2.1:OP:1:MU: β-Endorphin μ OPRM1 4988 18390 25601
Opioid 2.1:OP:4:NOCIC: Nociceptin/orphanin FQ NOP OPRL1 4987 18389 29256
Opsin-like OPN3 23596 13603
Orexin (hypocretin) Orexin A, orexin B OX1 HCRTR1 3061 230777 25593
Orexin (hypocretin) Orexin A, orexin B OX2 HCRTR2 3062 387285 25605
P2Y 2.1:NUCT:1:P2Y1: ADP P2Y1 P2RY1 5028 18441 25265
P2Y 2.1:NUCT:2:P2Y2: UTP, ATP P2Y2 P2RY2 5029 18442 29597
P2Y 2.1:NUCT:3:P2Y4: UTP P2Y4 P2RY4 5030 57385 63843
P2Y 2.1:NUCT:4:P2Y6: UDP P2Y6 P2RY6 5031 233571 117264
P2Y 2.1:NUCT:5:P2Y11: ATP P2Y11 P2RY11 5032
P2Y 2.1:NUCT:6:P2Y12: ADP [P2Y12] P2RY12 64805 70839 64803
P2Y 2.1:NUCT:7:P2Y13: ADP [P2Y13] P2RY13 53829 74191 310444
P2Y UDP-Glucose P2RY14 9934 140795 171108
Peptide P518 RF-Amide P518 gene productc GPR103 84109 243407
Platelet-activating factor 2.1:PAF:1:PAF Platelet-activating factor PAF PTAFR 5724 19204 58949
Prokineticin 2.1:PROK:1:PK1 Prokineticins 1 and 2 PK1 GPR73 10887 58182 192648
Prokineticin 2.1:PROK:2:PK2 Prokineticins 1 and 2 PK2 GPR73L1 128674 246313 192649
Prolactin-releasing peptide 2.1:PRP:1:PRP Prolactin-releasing peptide PRP GPR10 2834 226278 246075
Prostanoid 2.1:PG:1:DP: Prostaglandin D2 DP PTGDR 5729 19214 63889
Prostanoid 2.1:PG:2:EP1: Prostaglandin E2 EP1 PTGER1 5731 19216 25637
Prostanoid 2.1:PG:3:EP2: Prostaglandin E2 EP2 PTGER2 5732 19217 81752
Prostanoid 2.1:PG:4:EP3: Prostaglandin E2 EP3 PTGER3 5733 19218 24929
Prostanoid 2.1:PG:5:EP4: Prostaglandin E2 EP4 PTGER4 5734 19219 84023
Prostanoid 2.1:PG:6:FP: Prostaglandin F2a FP PTGFR 5737 19220 25652
Prostanoid 2.1:PG:7:IP: Prostacyclin IP1 PTGIR 5739 19222 292661
Prostanoid 2.1:PG:8:TP: Thromboxane A2 TP TBXA2R 6915 21390 24816
Prostanoid 11-Dehydrothromboxane B2c GPR44 11251 14764 29406
Protease-activated 2.1:PAR:1:PAR1 Thrombin PAR1 F2R 2149 14062 25439
Protease-activated 2:1:PAR:2:PAR2 Serine proteases PAR2 F2RL1 2150 14063 116677
Protease-activated 2.1:PAR:3:PAR3 Thrombin PAR3 F2RL2 2151 14064 29636
Protease-activated 2.1:PAR:4:PAR4 Serine proteases PAR4 F2RL3 9002 14065 116498
Relaxin Relaxin LGR7 59350 381489
Relaxin Relaxin LGR8 122042 170458 171158
Relaxin Relaxin-3 RLN3R1 51289 239336 294807
Relaxin INSL5, relaxin-3 RLN3R2 339403 242093
Somatostatin 2.1:SRIF:1:SRIF1A: Somatostatin sst2 SSTR2 6752 20606 54305
Somatostatin 2.1:SRIF:2:SRIF1B: Somatostatin sst5 SSTR5 6755 20609 25354
Somatostatin 2.1:SRIF:3:SRIF1C: Somatostatin sst3 SSTR3 6753 20607 171044
Somatostatin 2.1:SRIF:4:SRIF2A: Somatostatin sst1 SSTR1 6751 20605 25033
Somatostatin 2.1:SRIF:5:SRIF2B: Somatostatin sst4 SSTR4 6754 20608 25555
SPC/LPC (lyso)Phospholipid mediatorsd GPR65 8477 14744 299242
SPC/LPC (lyso)Phospholipid mediatorsd GPR4 2828 319197 308408
SPC/LPC (lyso)Phospholipid mediatorsd GPR68 8111 238377
SPC/LPC (lyso)Phospholipid mediatorsd GPR132 29933 56696 314480
Tachykinin 2.1:TAC:1:NK1: Substance P NK1 TACR1 6869 21336 24807
Tachykinin 2.1:TAC:2:NK2: Neurokinin A [NK2] TACR2 6865 21337 25007
Tachykinin 2.1:TAC:3:NK3: Neurokinin B NK3 TACR3 6870 21338 24808
Trace Amine β-Phenylethylamine, tyraminec [TA1] TRAR1 134864 111174 113914
TRH 2.1:TRH:1:TRH: Thyrotropin-releasing hormone TRH TRHR 7201 22045 25570
Urotensin 2.1:UT:1:UT1: Urotensin II UT UTS2R 2837 217369 57305
Vasopressin/oxytocin 2.1:OXY:1:OT: Oxytocin OT OXTR 5021 18430 25342
Vasopressin/oxytocin 2.1:VASO:1:V1A: Vasopressin V1A AVPR1A 552 54140 25107
Vasopressin/oxytocin 2.1:VASO:2:V2: Vasopressin V2 AVPR2 554 12000 25108
Vasopressin/oxytocin 2.1:VASO:3:V1B: Vasopressin V1B AVPR1B 553 26361 29462
OrphanA1 Sphingosine 1-phosphatec GPR3 2827 14748 266769
OrphanA1 Sphingosine 1-phosphatec GPR12 2835 14738 80840
OrphanA1 Sphingosine 1-phosphatec GPR6 2830 140741 83683
OrphanA2 GPR52 9293
OrphanA2 GPR21 2844 338346
OrphanA3 GPR78 27201
OrphanA3 GPR26 2849 233919 192153
OrphanA4 GPR37 2861 14763 117549
OrphanA4 GPR37L1 9283 171469 252939
OrphanA6 GPR63 81491 81006 297952
OrphanA6 GPR45 11250 93690 301372
OrphanA7 GPR83 10888 14608 140595
OrphanA9 GRCAe 27239 14788 362436
OrphanA9 GPR153 387509 100129
OrphanA12 Lysophosphatidic acidc GPR23 2846 78134 302378
OrphanA12 P2RY5 10161 67168
OrphanA13 P2RY10 27334 78826 317219
OrphanA13 GPR174 84636
OrphanA14 GPR142 350383 217302 303661
OrphanA14 GPR139 124274 293545
OrphanA15 ADMR 11318 11536 29307
OrphanA15 CMKOR1 57007 12778 84348
OrphanLGR LGR4 55366 107515 286994
OrphanLGR LGR5 8549 14160 299802
OrphanLGR LGR6 59352
OrphanSREB GPR85 54329 64450 64020
OrphanSREB GPR27 2850 14761 65275
OrphanSREB GPR173 54328 70771 64021
Orphan Succinatec SUCNR1 56670 84112 408199
Orphan α-Ketoglutaratec OXGR1 27199 239283 290493
Orphan (chemokine receptor-like) CCRL2 9034 54199
Orphan (Mas-related) MAS1 4142 17171 25153
Orphan (Mas-related) MAS1L 116511
Orphan (Mas-related) β-Alaninec MRGPRD 116512
Orphan (Mas-related) MRGPRE 116534
Orphan (Mas-related) MRGPRF 116535
Orphan (Mas-related) MRGPRG 386746
Orphan (Mas-related) BAM8—22c MRGX1e 259249 282547
Orphan (Mas-related) Cortistatinc MRGX2e 117194
Orphan (Mas-related) MRGX3e 117195
Orphan (Mas-related) MRGX4e 117196
Orphan (melatonin-like) GPR50 9248 14765 117097
Orphan (P2Y-like) GPR87 53836 84111
Orphan (trace amine-like) [TA3] TRAR3f 134860 319107
Orphan (trace amine-like) [TA4] TRAR4 319100 294124
Orphan (trace amine-like) [TA5] TRAR5 83551
Orphan (trace amine-like) PNRe 9038 294123
Orphan (trace amine-like) GPR57g 9288
Orphan (trace amine-like) GPR58 9287 294121
Other orphan genes RARRES2c CMKLR1 1240 14747 60669
Other orphan genes EBI2 1880 321019 306193
Other orphan genes GPR160 26996 71862
Other orphan genes GPRe 11245 117257
Other orphan genes GPR1 2825 241070 25457
Other orphan genes GPR101 83550 317608
Other orphan genes GPR119 139760 236781
Other orphan genes GPR120 338557 107221 294075
Other orphan genes GPR135 64582 314213
Other orphan genes OPN5 221391 353344 316259
Other orphan genes GPR141 353345 353346 291179
Other orphan genes GPR146 115330 80290
Other orphan genes GPR148 344561
Other orphan genes GPR149 344758 229357 192251
Other orphan genes GPR15 2838 288181
Other orphan genes GPR150 285601 238725
Other orphan genes GPR152 390212 269053
Other orphan genes GPR161 23432 289180
Other orphan genes GPR17 2840
Other orphan genes GPR171 29909 229323
Other orphan genes GPR18 2841 110168 306191
Other orphan genes GPR19 2842 14760 140664
Other orphan genes GPR20 2843 239530 60667
Other orphan genes GPR22 2845 73010
Other orphan genes GPR25 2848 363993
Other orphan genes GPR30 2852 76854 171104
Other orphan genes GPR31 2853 107431 292310
Other orphan genes GPR32 2854
Other orphan genes GPR33 2856 14762 299007
Other orphan genes GPR34 2857 23890
Other orphan genes GPR35 2859 64095
Other orphan genes GPR39 2863 71111
Other orphan genes GPR55 9290
Other orphan genes GPR61 83873 229714 310780
Other orphan genes GPR62 118442
Other orphan genes GPR75 10936 237716
Other orphan genes GPR79h 27200
Other orphan genes GPR82 27197 319200
Other orphan genes GPR84 53831 80910 367000
Other orphan genes GPR88 54112 64378 64443
Other orphan genes GPR92 57121
Other orphan genes P2RY8 286530
Other orphan genes GPR151 134391 240239 307475

  • BAM8—22, 15 amino acid C-terminal fragment of bovine adrenal medulla peptide 22.

  • ↵ a Very closely related to GPR41. May be a pseudogene

  • ↵ b Under review by IUPHAR

  • ↵ c Proposed ligand(s) supported by a single publication

  • ↵ d Sphingosine-1-phosphate, lysophosphatidic acid, sphingosylphosphorylcholine, and phosphatidic acid

  • ↵ e Interim gene symbol. The official symbol and name have not been established

  • ↵ f A polymorphism introduces a stop codon in some individuals

  • ↵ g May be a pseudogene

  • ↵ h Probable pseudogene