The Akt-glycogen synthase kinase 3beta pathway regulates transcription of atrial natriuretic factor induced by beta-adrenergic receptor stimulation in cardiac myocytes

J Biol Chem. 2000 May 12;275(19):14466-75. doi: 10.1074/jbc.275.19.14466.

Abstract

We examined the mechanism of atrial natriuretic factor (ANF) transcription by isoproterenol (ISO), an agonist for the beta-adrenergic receptor (betaAR), in cardiac myocytes. ISO only modestly activated members of the mitogen-activated protein kinase family. ISO-induced ANF transcription was not affected by inhibition of mitogen-activated protein kinases, whereas it was significantly inhibited by KN93, an inhibitor of Ca(2+)/calmodulin-dependent kinase (CaM kinase II). Production of 3'-phosphorylated phosphatidylinositides (3 phosphoinositides) was also required for ISO-induced ANF transcription. ISO caused phosphorylation (Ser-473) and activation of Akt through CaM kinase II- and 3 phosphoinositides-dependent mechanisms. Constitutively active Akt increased myocyte surface area, total protein content, and ANF expression, whereas dominant negative Akt blocked ISO-stimulated ANF transcription. ISO caused Ser-9 phosphorylation and decreased activities of GSK3beta. Overexpression of GSK3beta inhibited ANF transcription, which was reversed by ISO. ISO failed to reverse the inhibitory effect of GSK3beta(S9A), an Akt-insensitive mutant. Kinase-inactive GSK3beta increased ANF transcription. Cyclosporin A partially inhibited ISO-stimulated ANF transcription, indicating that calcineurin only partially mediates ANF transcription. These results suggest that both CaM kinase II and 3 phosphoinositides mediate betaAR-induced Akt activation and ANF transcription in cardiac myocytes. Furthermore, betaAR-stimulated ANF transcription is predominantly mediated by activation of Akt and subsequent phosphorylation/inhibition of GSK3beta.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Atrial Natriuretic Factor / genetics*
  • Calcineurin / physiology
  • Calcium / metabolism
  • Calcium-Calmodulin-Dependent Protein Kinases / antagonists & inhibitors
  • Calcium-Calmodulin-Dependent Protein Kinases / metabolism*
  • Cardiomegaly / enzymology
  • Cardiomegaly / metabolism
  • Gene Expression Regulation*
  • Glycogen Synthase Kinase 3
  • MAP Kinase Signaling System
  • Myocardium / cytology
  • Myocardium / metabolism*
  • Oncogene Protein v-akt
  • Phosphatidylinositol 3-Kinases / metabolism
  • Phosphorylation
  • Rats
  • Rats, Wistar
  • Receptors, Adrenergic, beta / physiology*
  • Retroviridae Proteins, Oncogenic / metabolism*
  • Transcription, Genetic*

Substances

  • Receptors, Adrenergic, beta
  • Retroviridae Proteins, Oncogenic
  • Atrial Natriuretic Factor
  • Phosphatidylinositol 3-Kinases
  • Oncogene Protein v-akt
  • Calcium-Calmodulin-Dependent Protein Kinases
  • Glycogen Synthase Kinase 3
  • Calcineurin
  • Calcium