Abstract
The postnatal alterations of the composition of a subunit isoforms (Giαc, G iα3 Goα, and Gqα of G proteins, the adenylyl cyclase activity as well as of cAMP-regulated phosphoproteins e.g. troponin and phospholamban were investigated in the ventricular tissue of 1, 7, 30 days old rats. Quantitative immunodetection revealed a 5.7-fold decrease in Giα3 at 30th postnatal day compared with the postnatal day 1 and up to 15-fold at 4 months. The amounts of Gqα and G∞ as well as the Gα subunits were found to be higher in the earlier life period compared to the adult. In contrast, the content of Gsα was uneffected by the developmental state. Basal adenylyl cyclase activity (pmoles cAMP/min × mg protein) increased from 30.9 ± 5.0, 36.8 ± 5.0 to 63.9 ± 5.9 at 1st, 7th and 30th postnatal day, respectively. Isoprenaline (100 μM) enhanced the activity of adenylyl cyclase from day 1, 7–30 from 46.2 ± 7.0, 79.1 ± 9.2 to 120.5 ± 7.2, respectively. The effects of forskolin and NaF on adenylyl cyclase activity was found to be not influenced within the first postnatal month. Furthermore, a developmentally controlled expression of cardiac troponin I was observed (6-fold from the first to the 28th postnatal day) whereas the level of phospholamban was found to be age-independent.
In conclusion, there is an increase in the efficiency of the β-adrenergic signal transfer mainly caused by a reduction of the inhibitiory G proteins and a dominance of the Gsα-linked pathway in the postnatal rat heart. Furthermore the developmentally controlled expression of troponin I might be of functional importance in the cAMP-supported relaxation. Additionally, altered Gqα, Goα and Gβ pattern of the developing rat ventricle may play a role in the observed change of α-adrenerg-mediated heart contractility as well as in cardiac differentiation and growth processes.
Similar content being viewed by others
References
Gilman AG: G proteins: transducers of receptor-generated signals. Annu Rev Biochem 56; 615–649, 1987
McMahon KK: Developmental changes of the G proteins-muscarinic cholinergic receptor interactions in rat heart. J Pharmacol Exp Ther 251:372–377, 1989
Brown AM: Regulation of heartbeat by G protein-coupled ion channels. Am J Physiol 259: H1621-H1628, 1990
Karczewski P, Bartel S, Krause EG: Differential sensitivity to isoprenaline of troponin I and phospholamban phosphorylation in isolated rat hearts. Biochem J 266: 115–122, 1990
Neer EJ, Clapham DE: Signal transduction through G proteins in the cardiac myocyte. Trends Cardiac Med 2: 6–11, 1992
Eschenhagen T: G Proteins and the heart. Cell Biol International 17: 723–749, 1993
Summers RJ, McMartin LR: Adrenoceptors and their second messenger systems. J Neurochem 60: 10–23, 1993
Hadcock JR, Malbon CC: Agonist regulation of gene expression of adrenergic receptors and G proteins. J Neurochem 60: 1–9, 1993
Luo W, Grupp IL, Harrer J, Ponniah S, Grupp D, Duffy T, Doetschmann K, Kranias EC: Target ablation of the phospholamban gene is associated with markedly enhanced myocardial contractility and loss of β-agonist stimulation. Circ Res 75: 401–409, 1994
Tobise K, Ishikawa Y, Holmer SR, Im MJ, Newell JB, Yoshie H, Fujita M, Susannie EE, CJ Homey: Changes in type VI adenylyl cyclase isoform expression correlate with a decreased capacity for cAMP generation in the ageing ventricle. Cite Res 74: 596–603, 1994
Mende U, Eschenhagen T, Geertz B, Schmitz W, Scholz H, Schulte am Esch J Sempell R, Steinfath M: Isoprenaline-induced increase in the 40/41 kDa pertusis toxin substrates and functional consequences on contractile response in rat heart. Naunyn Schmiedebergs Arch Pharmacol 345: 44–50, 1992
Eschenhagen T, Mende U, Nose M, Schmitz W, Scholz H: Long-term β-adrenoceptor-mediated upregulation of Giα- and G -mRNA levels and pertussis toxin sensitive G-proteins in rat heart. Mol Pharmacol 42:773–783, 1992
Eschenhagen T, Mende U, Nose M, Schmitz W, Scholz H, Haverich A, Hirt S, Döring V, Kalmar P, Hopper W, Seitz HJ: Increased messenger RNA level of the inhibitory G-protein α-subunit Giα-2 in human end-stage heart failure. Circ Res 70: 688–696, 1992
Bristow MR, Ginsburg R, Minobe W, Cubiccioti RS, Sageman WS, Lurie K, Billingham MW, Harrison DC, Stinson EB: Decreased catecholamine sensitivity and beta-adrenergic receptor density in failing human heart. N Engl J Med 307: 205–211, 1982
Feldman MD, Copeles L, Gwathmey JK, Philips P, Warren SE, Schoen FJ, Grossman W, Morgan JP: Deficient production of cyclic AMP: pharmacological evidence of an important cause of contractile dysfunction in patients with end-stage heart failure. Circulation 75: 331–339, 1987
Feldman AM, Ray PE, Bristow MR: Expression of α-subunits of G proteins in failing human heart: a reappraisal utilizing polymerase chain reaction. J Mol Cell Cardiol 23: 439–452, 1991
Neumann, Schmitz W, Scholz H, von Meyerinck L, Döring V, Kalmar P: Increase in myocardial Gi-proteins in human heart failure. Lancet 11: 936–937, 1988
Böhm M, Gierschik P, Jakobs KH, Pieske B, Schnabel P, Ungerer M, Erdmann E: Increase of Giα in human hearts with dilated but not ischemic cardiomyopathy. Circulation 82: 1249–1265, 1990
Kumar R, Joyner RW, Nartzell NC, Ellingsen D, Rishi F, Eaton DC, Lu C, Akita T: Postnatal changes in the G-proteins, cyclic nucleotides and adenylyl cyclase activity in rabbit heart cells. J Mol Cell Cardiol 26:1537–1550, 1994
Luetje CW, Tietje KM, Christian JL, Nathanson NM: Differential tissue expression and developmental regulation of guanine nucleotide binding regulatory proteins and their messenger RNAs in rat heart. J Biol Chem 263: 13357–13365, 1988
Espinasse I, Iourgenko V, Defer N, Samson F, Hanoune J, Mercadier JJ: Type V, but not type VI, adenylyl cyclase mRNA accumulates in the rat heart during ontogenic development. Correlation with increased global adenylyl cyclase activity. J Mol Cell Cardiol 27: 1789–1795, 1995
Kaufman TM, Horton JW White DJ, Mahony L: Age-related changes in myocardial relaxation and sarcoplasmic reticulum. Am J Physiol 259: H309-H316, 1990
Fischer PJ, Tate CA, Philipps S: Developmental regulation of the sarcoplasmic reticulum calcium pump in the rabbit heart. Pediatr Res 31: 474–479, 1992
Szymanska G, Grupp IL, Slack JP, Harrer JM, Kranias EG: Alterations in sarcoplasmic reticulum calcium uptake, relaxation parameters and their responses to β-adrenergic agonists in the developing rabbit heart. J Mol Cell Cardiol 27: 1819–1829, 1995
Vetter R, Studer R, Reinecke H, Kolar F, Ostadalova I, Drexler H: Reciprocal changes in the post-natal expression of the sarcolemmal Na+-Ca2+ exchanger and SERCA2 in rat heart. J Mol Cell Cardiol 27: 1689–1701, 1995
Wattanapermpoll J, Guo X, Solaro RJ: The unique amino-terminal peptide of cardiac troponin I regulates myofibrillar activity only when it is phosphorylated. J Mol Cell Cardiol 27: 1383–1391, 1995
Artmann M, Kithas PA, Wike JS, Strada SJ: Inotropic responses during postnatal maturation in rabbit. Am J Physiol 255: H335-H342, 1988
Martin AF, Ball K, Gao LZ, Kumar P, Solaro RJ: Identification and functional significance of troponin I isoforms in neonatal rat heart myofibrils. Circ Res 69: 1244–1252, 1991
Bartel S, Morano I, Hunger HD, Katus H, Pask HT, Karczewski P, Krause EG: Cardiac troponin I and tension generation of skinned fibers in the developing rat heart. J Mol Cell Cardiol 26: 1123–1121, 1994
Lowry OH, Rosebrough NJ, Farr AC, Randell RJ: Protein measurement with folin phenol reagent. J Biol Chem 193: 265–275, 1951
Laemmli UK: Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature 277: 680–685, 1970
Will-Shahab L, Rosenthal W, Schulze W, Küttner I: G protein function in the ischemic myocardium. Eur Heart J 12: 135–138, 1991
Saloman Y: Londos C, Rodbell MA: A highly sensitive adenylate cyclase assay. Anal Biochem 58: 541–548, 1974
White AA, Zenser TV: Separation of cyclic 3′5′,-nucleotide monophosphates from other nucleotides on aluminium oxide columns. Analyt Biochem 43: 272–282, 1971
Fleming JW, Wisler PL, Watanabe AM: Signal transduction by G proteins on cardiac tissues. Circulation 85: 420–133, 1992
Foster KA, McDermott PJ, Robishaw JD: Expression of G proteins in rat cardiac myocytes: effect of KCl depolarization. Am J Physiol 259: H432-H441, 1990
Moriartry TM, Padrell E, Carty DJ, Omry G, Landau EM, Iyengar R: Go protein as signal transducer in the pertussis toxin-sensitive phosphatidylinositol pathway. Nature 343: 79–89, 1990
Hescheler J, Rosenthal W, Traustwin W, Schultz G: The GTP-binding protein Go regulates neuronal calcium channels. Nature 325: 445–1147, 1987
Jiang MT, Moffat MP, Narayanan N: Age-related alterations in the phosphorylation of sarcoplasmic reticulum and myofibrillar proteins and diminished contractile response to isoprenaline in intact rat ventricle. Circ Res 72: 102–111, 1993
Brillantes AM, Bezprozvannnaya S, Marks AR: Developmental and tissue-specific regulation of rabbit skeletal and cardiac muscle calcium channels involved in excitation-contraction coupling. Circ Res 75:503–510, 1994
Sasse S, Brand NJ, Kyprioanou P, Dhoot GK, Wade R, Arai M, Periasamy, Yacoub MH, Barten PJR: Troponin I gene expression during human cardiac development and in end-stage heart failure. Circ Res 72: 932–938, 1993
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Bartel, S., Karczewski, P. & Krause, EG. G proteins, adenylyl cyclase and related phosphoproteins in the developing rat heart. Mol Cell Biochem 163, 31–38 (1996). https://doi.org/10.1007/BF00408638
Issue Date:
DOI: https://doi.org/10.1007/BF00408638