GRK3 mediates desensitization of CRF1 receptors: a potential mechanism regulating stress adaptation.
Potential G protein-coupled receptor kinase (GRK) and protein kinase A (PKA) mediation of homologous desensitization of corticotropin-releasing factor type 1 (CRF1) receptors was investigated in human retinoblastoma Y-79 cells. Inhibition of PKA activity by PKI(5-22) or H-89 failed to attenuate homologous desensitization of CRF1 receptors, and direct activation of PKA by forskolin or dibutyryl cAMP failed to desensitize CRF-induced cAMP accumulation. However, treatment of permeabilized Y-79 cells with heparin, a nonselective GRK inhibitor, reduced homologous desensitization of CRF1 receptors by approximately 35%. Furthermore, Y-79 cell uptake of a GRK3 antisense oligonucleotide (ODN), but not of a random or mismatched ODN, reduced GRK3 mRNA expression by approximately 50% without altering GRK2 mRNA expression and inhibited homologous desensitization of CRF1 receptors by approximately 55%. Finally, Y-79 cells transfected with a GRK3 antisense cDNA construct exhibited an approximately 50% reduction in GRK3 protein expression and an ~65% reduction in homologous desensitization of CRF1 receptors. We conclude that GRK3 contributes importantly to the homologous desensitization of CRF1 receptors in Y-79 cells, a brain-derived cell line.
Pharma Division, Preclinical Research, F-Hoffmann-La Roche Ltd., CH-4070 Basel, Switzerland.
F M
FM
Dautzenberg
S
S
Braun
R L
RL
Hauger
D005576:Colforsin / Q000494:pharmacology; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D016373:DNA, Antisense; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005134:Eye Neoplasms; D054770:G-Protein-Coupled Receptor Kinase 3; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects / Q000502:physiology; D006801:Humans; D007546:Isoquinolines / Q000494:pharmacology; D020319:Oligodeoxyribonucleotides, Antisense / Q000494:pharmacology; D010446:Peptide Fragments / Q000494:pharmacology; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D018019:Receptors, Corticotropin-Releasing Hormone / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D011994:Recombinant Proteins / Q000378:metabolism; D012175:Retinoblastoma; D013449:Sulfonamides; D014158:Transcription, Genetic / Q000187:drug effects; D014162:Transfection; D014407:Tumor Cells, Cultured; D051552:beta-Adrenergic Receptor Kinases; D000099052:CRF Receptor, Type 1
D016373:DNA, Antisense; D004791:Enzyme Inhibitors; D007546:Isoquinolines; D020319:Oligodeoxyribonucleotides, Antisense; D010446:Peptide Fragments; D012333:RNA, Messenger; D018019:Receptors, Corticotropin-Releasing Hormone; D011994:Recombinant Proteins; D013449:Sulfonamides; D005576:Colforsin; D000099052:CRF Receptor, Type 1; D017346:Protein Serine-Threonine Kinases; D017868:Cyclic AMP-Dependent Protein Kinases; D054770:G-Protein-Coupled Receptor Kinase 3; C517848:GRK3 protein, human; D051552:beta-Adrenergic Receptor Kinases; C063509:N-(2-(4-bromocinnamylamino)ethyl)-5-isoquinolinesulfonamide