TY - JOUR
T1 - Multiple kinases phosphorylate the pancreatic cholecystokinin receptor in an agonist-dependent manner
AU - Gates, L. K.
AU - Ulrich, C. D.
AU - Miller, L. J.
PY - 1993
Y1 - 1993
N2 - The cholecystokinin (CCK) receptor on the rat pancreatic acinar cell is a guanine nucleotide-binding protein (G protein)-coupled receptor, which was recently demonstrated to be phosphorylated in response to agonist stimulation (Klueppelberg et al., J. Biol. Chem. 266: 17744-17746, 1991). In this work, we establish that this receptor is phosphorylated in response to a variety of homologous and heterologous secretagogues and that these phosphorylation events represent action by more than one protein kinase. One subgroup of kinases includes one or more isotype of protein kinase C (PKC), and is capable of playing a role in homologous and heterologous desensitization. A second subgroup of kinases that acts on the CCK receptor was defined by its resistance to 10 μM staurosporine, which was shown to inhibit all PKC in these cells. The activity of the second group of kinases was observed only in response to occupation of the CCK receptor by high concentrations of native hormone, raising the possibility of a 'receptor-specific kinase.' Similar to the prototypical kinase, β-adrenergic receptor kinase (β-ARK), this activity was inhibited in permeabilized cells by heparin. Furthermore, like this enzyme activity, β-ARK was shown to be resistant to staurosporine. Based on its action on a G protein-coupled receptor, its activation at high concentrations of native agonist, and its pattern of inhibition, we believe that the staurosporine-insensitive CCK receptor kinase activity represents either β-ARK or a closely related member of the receptor-specific kinase enzyme family.
AB - The cholecystokinin (CCK) receptor on the rat pancreatic acinar cell is a guanine nucleotide-binding protein (G protein)-coupled receptor, which was recently demonstrated to be phosphorylated in response to agonist stimulation (Klueppelberg et al., J. Biol. Chem. 266: 17744-17746, 1991). In this work, we establish that this receptor is phosphorylated in response to a variety of homologous and heterologous secretagogues and that these phosphorylation events represent action by more than one protein kinase. One subgroup of kinases includes one or more isotype of protein kinase C (PKC), and is capable of playing a role in homologous and heterologous desensitization. A second subgroup of kinases that acts on the CCK receptor was defined by its resistance to 10 μM staurosporine, which was shown to inhibit all PKC in these cells. The activity of the second group of kinases was observed only in response to occupation of the CCK receptor by high concentrations of native hormone, raising the possibility of a 'receptor-specific kinase.' Similar to the prototypical kinase, β-adrenergic receptor kinase (β-ARK), this activity was inhibited in permeabilized cells by heparin. Furthermore, like this enzyme activity, β-ARK was shown to be resistant to staurosporine. Based on its action on a G protein-coupled receptor, its activation at high concentrations of native agonist, and its pattern of inhibition, we believe that the staurosporine-insensitive CCK receptor kinase activity represents either β-ARK or a closely related member of the receptor-specific kinase enzyme family.
KW - G protein
KW - desensitization
KW - β-adrenergic receptor kinase
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U2 - 10.1152/ajpgi.1993.264.5.g840
DO - 10.1152/ajpgi.1993.264.5.g840
M3 - Article
C2 - 8498511
AN - SCOPUS:0027243579
SN - 0002-9513
VL - 264
SP - G840-G847
JO - American Journal of Physiology - Gastrointestinal and Liver Physiology
JF - American Journal of Physiology - Gastrointestinal and Liver Physiology
IS - 5 27-5
ER -