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Class A Orphans C

Contents

Overview

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Table 1 lists a number of putative GPCRs identified by NC-IUPHAR [2], for which preliminary evidence for an endogenous ligand has been published, or for which there exists a potential link to a disease, or disorder. These GPCRs have recently been reviewed in detail [1]. The GPCRs in Table 1 are all Class A, rhodopsin-like GPCRs. Class A orphan GPCRs not listed in Table 1 are putative GPCRs with as-yet unidentified endogenous ligands.

Table 1: Class A orphan GPCRs with putative endogenous ligands

GPR3GPR4GPR6GPR12GPR15GPR17GPR20
GPR22GPR26GPR31GPR34GPR35GPR37GPR39
GPR50GPR63GPR65GPR68GPR75GPR84GPR87
GPR88GPR132GPR149GPR161GPR183LGR4LGR5
LGR6MAS1MRGPRDMRGPRX1MRGPRX2P2RY10TAAR2

In addition the orphan receptors GPR18, GPR55 and GPR119 which are reported to respond to endogenous agents analogous to the endogenous cannabinoid ligands have been grouped together (GPR18, GPR55 and GPR119).

Subfamilies

Families that contain targets of relevance to immunopharmacology are highlighted in blue

Further reading

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References

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NC-IUPHAR subcommittee and family contributors

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How to cite this family page

Database page citation (select format):

Alexander SP, Battey J, Benson HE, Benya RV, Bonner TI, Davenport AP, Dhanachandra Singh K, Eguchi S, Harmar A, Holliday N, Irving AJ, Jensen RT, Karnik S, Kostenis E, Liew WC, Monaghan AE, Mpamhanga C, Neubig R, Pawson AJ, Pin JP, Sharman JL, Spedding M, Spindel E, Stoddart L, Storjohann L, Thomas WG, Tirupula K, Vanderheyden P. Class A Orphans (version 2025.1) in the IUPHAR/BPS Guide to Pharmacology Database. IUPHAR/BPS Guide to Pharmacology CITE. 2025; 2025(1). Available from: https://doi.org/10.2218/gtopdb/F16/2025.1.

Concise Guide to PHARMACOLOGY citation:

Alexander SPH, Christopoulos A, Davenport AP, Kelly E, Mathie A, Peters JA, Veale EL, Armstrong JF, Faccenda E, Harding SD, Pawson AJ, Sharman JL, Southan C, Davies JA; CGTP Collaborators. (2019) The Concise Guide to PHARMACOLOGY 2019/20: G protein-coupled receptors. Br J Pharmacol. 176 Issue S1: S21-S141.