scholarly journals Characterization of cAMP-dependent protein kinase activation by CCK in rat pancreas

FEBS Letters ◽  
1993 ◽  
Vol 316 (1) ◽  
pp. 48-52 ◽  
Author(s):  
Christopher R. Marino ◽  
Steven D. Leach ◽  
Jean F. Schaefer ◽  
Laurence J. Miller ◽  
Fred S. Gorelick
Keyword(s):  
Protein Kinase ◽  
Dependent Protein Kinase ◽  
Kinase Activation ◽  
Rat Pancreas ◽  
Camp Dependent Protein Kinase ◽  
Protein Kinase Activation ◽  
Dependent Protein

scholarly journals The type III inositol 1,4,5-trisphosphate receptor is phosphorylated by cAMP-dependent protein kinase at three sites

2005 ◽  
Vol 392 (3) ◽  
pp. 493-497 ◽  
Author(s):  
Matthew D. Soulsby ◽  
Richard J. H. Wojcikiewicz
Keyword(s):  
Protein Kinase ◽  
Ip3 Receptor ◽  
Dependent Protein Kinase ◽  
Kinase Activation ◽  
Type Iii ◽  
Camp Dependent Protein Kinase ◽  
Protein Kinase Activation ◽  
Inositol 1,4,5 Trisphosphate ◽  
Functional Consequences ◽  
Dependent Protein

IP3 (inositol 1,4,5-trisphosphate) receptors form tetrameric, IP3-gated Ca2+ channels in endoplasmic reticulum membranes, and are substrates for several kinases, including PKA (cAMP-dependent protein kinase). Activation of PKA has been reported to either enhance or inhibit type III IP3 receptor Ca2+-channel activity, but, as yet, the sites of phosphorylation remain unknown. Here, we reveal that PKA phosphorylates the type III IP3 receptor at Ser916, Ser934 and Ser1832, and that, intriguingly, each site is located close to a putative surface-exposed peptide loop. Furthermore, we demonstrate that Ser934 is considerably more susceptible to PKA-dependent phoshorylation than either Ser916 or Ser1832. These findings define the sites at which the type III IP3 receptor is phosphorylated by PKA, and provide the basis for exploring the functional consequences of this regulatory event.

Involvement of cAMP-dependent protein kinase in the regulation of heart contractile force

1977 ◽  
Vol 233 (2) ◽  
pp. H269-H275 ◽  
Author(s):  
S. L. Keely ◽  
J. D. Corbin
Keyword(s):  
Protein Kinase ◽  
Kinase Activity ◽  
Contractile Force ◽  
Filling Pressure ◽  
Protein Kinase Activity ◽  
Dependent Protein Kinase ◽  
Kinase Activation ◽  
Camp Dependent Protein Kinase ◽  
Protein Kinase Activation ◽  
Dependent Protein

The effects of perfusate epinephrine, 1-methyl-3-isobutylxanthine, calcium, and filling pressure were investigated in the perfused working rat heart. Epinephrine produced a rapid increase in cAMP, in the protein kinase activity ratio, and in active phosphorylase. These effects preceded the increase in contractile force produced by the hormone. There was good correlation between protein kinase activation and the increase in force. Epinephrine and the phosphodiesterase inhibitor 1-methyl-3-isobutylxanthine were synergistic in their stimulatory effects on cAMP, protein kinase activity, active phosphorylase, and contractile force. When an increase in the force of contraction was produced either by increasing the filling pressure of the heart or by increasing the perfusate Ca2+ concentration, there was no change in either cAMP levels or protein kinase activity. These data suggest that the effect of beta-adrenergic catecholamines on contractile force is due, at least in part, to cAMP-dependent protein kinase activation. The increase in contractile force produced either by increasing the filling pressure (Frank-Starling phenomenon) or by increasing the perfusate Ca2+ concentration is apparently not mediated by cAMP or the protein kinase.

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