The gastrin-releasing peptide receptor is rapidly phosphorylated by a kinase other than protein kinase C after exposure to agonist.
Several guanine nucleotide-binding protein-coupled receptors are known to be rapidly phosphorylated after agonist exposure. In this study we show that the gastrin-releasing peptide receptor (GRP-R) is rapidly phosphorylated in response to agonist exposure. When [32P]orthophosphate-labeled cells were exposed to bombesin, the receptor was maximally phosphorylated on serine and threonine residues within 1 min. Although addition of 12-O-tetradecanoylphorbol 13-acetate also resulted in phosphorylation of the GRP-R, elimination of protein kinase C activity using the inhibitor 7-hydroxystaurosporine did not prevent bombesin-induced GRP-R phosphorylation. We conclude that a kinase other than protein kinase C is principally responsible for the rapid, agonist-induced phosphorylation of the GRP-R.
Kroog
G S
GS
Laboratory of Biological Chemistry, NCI National Institutes of Health, Bethesda, Maryland 20892-4255, USA.
Sainz
E
E
Worland
P J
PJ
Akeson
M A
MA
Benya
R V
RV
Jensen
R T
RT
Battey
J F
JF
D000595:Amino Acid Sequence; D000818:Animals; D001839:Bombesin / Q000494:pharmacology; D002478:Cells, Cultured; D004789:Enzyme Activation; D007106:Immune Sera; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D010766:Phosphorylation; D011493:Protein Kinase C / Q000378:metabolism*; D011494:Protein Kinases / Q000378:metabolism*; D018004:Receptors, Bombesin / Q000819:agonists / Q000276:immunology / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014162:Transfection
D007106:Immune Sera; D018004:Receptors, Bombesin; D011494:Protein Kinases; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate; D001839:Bombesin