Heterologous desensitization of bombesin- and vasopressin-stimulated phospholipase D activity in Swiss 3T3 fibroblasts.
Bombesin- and vasopressin-stimulated phospholipase D (PLD) activities are rapidly desensitized in 3T3 cells, in addition both agonists are subject to heterologous desensitization. Binding studies showed that homologous desensitization was partly a result of loss of cell surface receptors, whilst heterologous desensitization was independent of receptor changes. Pretreatment with either agonist reduced subsequent GTP gamma S-stimulated PLD activity by 50% whereas a pretreatment with GTP gamma S did not attenuate the response, suggesting that the G-protein or downstream effector systems were affected by receptor activation resulting in desensitization. The desensitization of receptor-stimulated PLD activation provides support for the phospholipase functioning in a key signalling pathway.
Briscoe
C P
CP
University of Birmingham Institute for Cancer Studies, Queen Elizabeth Hospital, Birmingham, UK.
Wakelam
M J
MJ
D016475:3T3 Cells; D000818:Animals; D001127:Arginine Vasopressin / Q000037:antagonists & inhibitors / Q000378:metabolism* / Q000494:pharmacology*; D001839:Bombesin / Q000494:pharmacology*; D004789:Enzyme Activation; D005347:Fibroblasts / Q000201:enzymology; D019204:GTP-Binding Proteins / Q000378:metabolism; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000494:pharmacology; D007700:Kinetics; D051379:Mice; D010739:Phospholipase D / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000378:metabolism; D017483:Receptors, Vasopressin / Q000378:metabolism; D015398:Signal Transduction
D011956:Receptors, Cell Surface; D017483:Receptors, Vasopressin; D001127:Arginine Vasopressin; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D010739:Phospholipase D; D019204:GTP-Binding Proteins; D001839:Bombesin