Table 9

G protein coupling of the four adenosine receptor subtypes

Adenosine Receptor SubtypeG ProteinEffects of G Protein CouplingCellular SystemReference
A1 Gi1/2/3 ↓ cAMP
↑ IP3/DAG (PLC)
↑ Arachidonate (PLA2)		General, CHO cells9-a Freissmuth et al., 1991; Akbar et al., 1994; Freund et al., 1994; Jockers et al., 1994;Gerwins and Fredholm, 1995a,b
↑ PEtOH (PLD)DDT1MF-2
Go Jockers et al., 1994;Matovcik et al., 1994
A2A Gs ↑ cAMPGeneral Olah, 1997
Golf ↑ cAMP Kull et al., 2000a; Corvol et al., 2001
G15/16 ↑ IP3 COS-79-a Offermanns and Simon, 1995
A2B Gs ↑ cAMPGeneral Pierce et al., 1992
Gq/11 ↑ IP3/DAG (PLC)HMC-1, HEK 2939-a Gao et al., 1999; Linden et al., 1999 9-b
A3 Gi2,3 ↓ cAMPGeneral, CHO cells9-a Palmer et al., 1995
Gq/11 ↑ IP3/DAG (PLC)CHO cells9-a Palmer et al., 1995

  • ↵9-a  Receptor transfected cell system.

  • ↵9-b  References propose Gq/11 coupling without direct evidence for Gq/11 activation.