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Cyclic AMP-Dependent Activation of Protein Kinases in the Myocardium

  • J. G. DobsonJr.

Summary

Upon catecholamine stimulation of the heart, the cyclic AMP-dependent activation of protein kinases appears to play an important role in the enhancement of contractility and glycogenolysis presumably by promoting the phosphorylation of myocardial proteins. In the intact rat heart, epinephrine produced a rapid elevation of myocardial cyclic AMP and activation of both cyclic AMP-dependent protein kinase and phosphorylase b kinase within 5–10 sec. This preceded the conversion of phosphorylase b to phosphorylase a and the augmentation of contractile state that occurred within 12–18 sec. The β-adrenergic blocking agent, practolol, had no effect on the basal levels of the above parameters, but did prevent the epinephrine produced increases. The importance of catecholamine activation of the kinases in catalyzing protein phosphorylation was investigated in isolated myocardial preparations previously exposed to 32P to label intracellular ATP. In ventricular muscle slices, isoproterenol increased the 32P incorporation into trichloroacetic acid insoluble protein as well as the phosphate content of this protein. In isolated perfused hearts, the catecholamine produced an increase in 32P incorporation into a 29000Xg (membrane and mitochondria) and 100 000 × g (sarcoplasmic reticulum) pellet fractions and a 100 000 × g soluble fraction within 30 sec. While the β-adrenergic blocking agent, propranolol, did not by itself affect 32P incorporation, it prevented the isoproterenol-induced incorporation of 32P into the pellet and soluble fractions and the acid-insoluble protein. Removal of isoproterenol from the isolated preparations eliminated the differences in 32P incorporation indicating that the effects of the catecholamines were reversible. Sodium dodecyl sulfate gel electrophoresis of ventricular muscle homogenates of isolated perfused hearts revealed that isoproterenol enhanced the 32P incorporation into several myocardial proteins having molecular weights of 155 000, 92 000, 30 000, 16 000 and 13 000 within 30 sec. These findings are consistent with the notion that cyclic AMP-dependent activation of protein kinases by catecholamine stimulation enhances the phosphorylation of myocardial proteins which in turn may play an important role in the augmentation of contractility and glycogenolysis.

Keywords

Perfuse Heart Contractile State Cardiac Sarcoplasmic Reticulum Glycogen Phosphorylase Activity Myocardial Protein 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. 1.
    Brown DF, Honeyman TW, Dobson JG Jr (1978) Properties of epinephrine-induced activation of cardiac adenosine 3′,5′-monophosphate-dependent protein kinase. Biochim Biophys Acta 544: 462–473PubMedGoogle Scholar
  2. 2.
    Cogoli JM, Dobson JG Jr (1981) An easy and rapid method for the measurement of [γ-32P]ATP specific radioactivity in tissue extracts obtained from in vitro rat heart preparations labeled with 32Pi. Anal Biochem 110: 331–337PubMedCrossRefGoogle Scholar
  3. 3.
    Dobson JG Jr (1978) Protein kinase regulation of cardiac phosphorylase activity and contractility. Am J Physiol 234. H638–H645PubMedGoogle Scholar
  4. 4.
    Dobson JG Jr (1981) Catecholamine-induced phosphorylation of cardiac muscle proteins. Biochim Biophys Acta 675: 123–131PubMedGoogle Scholar
  5. 5.
    Dobson JG Jr, Mayer SE (1973) Mechanisms of activation of cardiac glycogen phosphorylase in ischemia. Circ Res 33: 412–420PubMedGoogle Scholar
  6. 6.
    Dobson JG Jr, Ross J Jr, Mayer SE (1976) The role of adenosine 3′,5′-monophosphate and calcium in the regulation of contractility and glycogen phosphorylase activity in guinea pig papillary muscle. Circ Res 39: 388–395PubMedGoogle Scholar
  7. 7.
    England PJ (1976) Studies on the phosphorylation of the inhibitory subunit of troponin during modification of contraction in perfused rat heart. Biochem J 160: 295–304PubMedGoogle Scholar
  8. 8.
    Frearson N, Solaro RJ, Perry SV (1976) Changes in phosphorylation of P light chain of myosin in perfused rabbit heart. Nature 264: 801–802PubMedCrossRefGoogle Scholar
  9. 9.
    Holroyde MJ, Howe E, Solaro RJ (1979) Modification of calcium requirements for activation of cardiac myofibrillar ATPase by cyclic AMP dependent phosphorylation. Biochim Biophys Acta 586: 63–69Google Scholar
  10. 10.
    Itaya K, Ui M (1966) A new micromethod for the colorimetric determinations of inorganic phosphate. Clin Chim Acta 14: 361–366PubMedCrossRefGoogle Scholar
  11. 11.
    Keely SL, Corbin JD (1977) Involvement of cAMP-dependent protein kinase in the regulation of heart contractile force. Am J Physiol 233: H269–H275PubMedGoogle Scholar
  12. 12.
    Kirchberger MA, Chu G (1976) Correlation between protein kinase-mediated stimulation of calcium transport by cardiac sarcoplasmic reticulum and phosphorylation of a 22 000 dalton protein. Biochim Biophys Acta 419: 559–562PubMedCrossRefGoogle Scholar
  13. 13.
    Kopp SJ, Barany M (1979) Phosphorylation of the 19 000-dalton light chain of myosin in perfused rat heart under the influence of negative and positive inotropic agents. J Biol Chem 254: 12007–12012Google Scholar
  14. 14.
    LaRaia PJ, Morkin E (1974) Adenosine 3′,5′-monophosphate-dependent membrane phosphorylation. A possible mechanism for the control of microsomal calcium transport in heart muscle. Circ Res 35: 298–306Google Scholar
  15. 15.
    Manning DR, DiSalvo J, Stull JT (1980) Protein phosphorylation: Quantitative analysis in vivo and in intact cell systems. Mol Cell Endocrinol 19: 1–19PubMedCrossRefGoogle Scholar
  16. 16.
    Namm DH, Mayer SE (1968) Effects of epinephrine on cardiac cyclic 3′,5′-AMP, phosphorylase kinase and phosphorylase. Mol Pharmacol 4: 61–69PubMedGoogle Scholar
  17. 17.
    Offer G, Moos C, Starr R (1973) A new protein of the thick filament of vertebrate skeletal myofibrils. Extraction, purification and characterization. J Mol Biol 74: 653–676PubMedCrossRefGoogle Scholar
  18. 18.
    Robison GA, Butcher RW, Oye I, Morgan HE, Sutherland EW (1965) The effect of epinephrine on adenosine 3′,5′-phosphate levels in the isolated perfused rat heart. Mol Pharmacol 1: 168–177PubMedGoogle Scholar
  19. 19.
    Schwartz A, Entman ML, Kanicki K, Lane LK, van Winkle WB, Bornet EP (1976) The rate of calcium uptake into sarcoplasmic reticulum of cardiac muscle and skeletal muscle. Effects of cyclic AMP-dependent protein kinase and phosphorylase b kinase. Biochim Biophys Acta 426: 57–72PubMedCrossRefGoogle Scholar
  20. 20.
    Sokal RR, Rohlf FJ (1969) Biometry. Freeman, San Francisco, pp 175–203Google Scholar
  21. 21.
    Solaro RJ, Moir AJG, Perry SV (1976) Phosphorylation of troponin I and the inotropic effect of adrenaline in the perfused rabbit heart. Nature 262: 615–617PubMedCrossRefGoogle Scholar
  22. 22.
    Sulakhe PV, St Louis PJ (1976) Membrane phosphorylation and calcium transport in cardiac and skeletal muscle membranes. Gen Pharmacol 7: 313–319PubMedCrossRefGoogle Scholar
  23. 23.
    Tada M, Kirchberger MA, Katz AM (1975) Phosphorylation of a 22 000-dalton component of the cardiac sarcoplasmic reticulum by adenosine 3′,5′-monophosphate-dependent protein kinase. J Biol Chem 250: 2640–2647PubMedGoogle Scholar
  24. 24.
    Walsh DA, Perkins JP, Brostrom CO, Ho ES, Krebs EG (1971) Catalysis of the Phosphorylase kinase activation reaction. J Biol Chem 246: 1968–1976PubMedGoogle Scholar
  25. 25.
    Walsh DA, Clippinger MS, Sivaramakrishnan S, McCullough TE (1979) Cyclic adenosine monophosphate dependent and independent phosphorylation of sarcolemma membrane proteins in perfused rat heart. Biochemistry 18: 871–877PubMedCrossRefGoogle Scholar
  26. 26.
    Wray HL, Gray RR (1977) Cyclic AMP stimulation of membrane phosphorylation and Ca2+-activated, Mg2+-dependent ATPase in cardiac sarcoplasmic reticulum. Biochim Biophys Acta 461: 441–459PubMedCrossRefGoogle Scholar
  27. 27.
    Wyborny LE, Reddy YS (1978) Phosphorylated cardiac myofibrils and their effect on ATPase activity. Biochem Biophys Res Commun 81:1175–1179Chem 250: 2640–2647Google Scholar

Copyright information

© Springer-Verlag, Berlin, Heidelberg 1981

Authors and Affiliations

  • J. G. DobsonJr.

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