title: Inhibitory coupling of hormone and neurotransmitter receptors to adenylate cyclase.
abstract: The last few years have provided evidence that beside the familiar and partially well characterized stimulation of the adenylate cyclase the enzyme is also subject to a hormone and neurotransmitter-induced inhibition serving as a general information-transfer system. Similar to hormonal stimulation, the coupling of the inhibitory hormone receptors to adenylate cyclase is mediated by a GTP-dependent process. In some membrane systems, the inhibitory coupling is additionally amplified by sodium ions. Inhibitory hormones stimulate a high affinity GTPase in plasma membranes. The observed correlation suggests that there is a close connection between the hormone-induced adenylate cyclase inhibition and GTPase stimulation. Several lines of evidence are presented suggesting that the guanine nucleotide-dependent component apparently involved in adenylate cyclase inhibition and apparently exhibiting GTPase activity is at least partially different from that involved in adenylate cyclase stimulation by hormones.
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D001792:Blood Platelets / Q000378:metabolism; D002478:Cells, Cultured; D006150:Guanine Nucleotides / Q000502:physiology; D006160:Guanosine Triphosphate / Q000378:metabolism; D006801:Humans; D006868:Hydrolysis; D066298:In Vitro Techniques; D007700:Kinetics; D011485:Protein Binding; D017981:Receptors, Neurotransmitter / Q000378:metabolism*
chemical_list: D006150:Guanine Nucleotides; D017981:Receptors, Neurotransmitter; D006160:Guanosine Triphosphate; D000262:Adenylyl Cyclases