Muscarinic supersensitivity and impaired receptor desensitization in G protein-coupled receptor kinase 5-deficient mice.

Journal Article

G protein-coupled receptor kinase 5 (GRK5) is a member of a family of enzymes that phosphorylate activated G protein-coupled receptors (GPCR). To address the physiological importance of GRK5-mediated regulation of GPCRs, mice bearing targeted deletion of the GRK5 gene (GRK5-KO) were generated. GRK5-KO mice exhibited mild spontaneous hypothermia as well as pronounced behavioral supersensitivity upon challenge with the nonselective muscarinic agonist oxotremorine. Classical cholinergic responses such as hypothermia, hypoactivity, tremor, and salivation were enhanced in GRK5-KO animals. The antinociceptive effect of oxotremorine was also potentiated and prolonged. Muscarinic receptors in brains from GRK5-KO mice resisted oxotremorine-induced desensitization, as assessed by oxotremorine-stimulated [5S]GTPgammaS binding. These data demonstrate that elimination of GRK5 results in cholinergic supersensitivity and impaired muscarinic receptor desensitization and suggest that a deficit of GPCR desensitization may be an underlying cause of behavioral supersensitivity.

Full Text

Duke Authors

Cited Authors

  • Gainetdinov, RR; Bohn, LM; Walker, JK; Laporte, SA; Macrae, AD; Caron, MG; Lefkowitz, RJ; Premont, RT

Published Date

  • December 1999

Published In

Volume / Issue

  • 24 / 4

Start / End Page

  • 1029 - 1036

PubMed ID

  • 10624964

International Standard Serial Number (ISSN)

  • 0896-6273

Language

  • eng

Conference Location

  • United States