Glycogen synthase kinase-3 represses cyclic AMP response element-binding protein (CREB)-targeted immediate early genes in quiescent cells

J Biol Chem. 2007 Mar 30;282(13):9482-9491. doi: 10.1074/jbc.M700067200. Epub 2007 Feb 3.

Abstract

Despite its central role in cell survival and proliferation, the transcriptional program controlled by GSK-3 is poorly understood. We have employed a systems level approach to characterize gene regulation downstream of PI 3-kinase/Akt/GSK-3 signaling in response to growth factor stimulation of quiescent cells. Of 31 immediate-early genes whose induction was dependent on PI 3-kinase signaling, 12 were induced directly by inhibition of GSK-3. Most of the GSK-3-regulated genes encoded transcription factors, growth factors, and signaling molecules. Binding sites for CREB were highly over-represented in the upstream regions of these genes, with 9 genes containing CREB sites that were conserved in mouse orthologs. Binding sites predicted in 6 genes were confirmed by CREB chromatin immunoprecipitation and forskolin induction of CBP binding. Moreover, CREB siRNA substantially blocked induction of 5 genes by forskolin and of 3 genes following inhibition of GSK-3. These results indicate that GSK-3 actively represses gene expression in quiescent cells, with inhibition of CREB playing a key role in this transcriptional response.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Cell Line, Tumor
  • Cyclic AMP Response Element-Binding Protein / antagonists & inhibitors*
  • Cyclic AMP Response Element-Binding Protein / physiology
  • Gene Expression Regulation, Neoplastic / physiology*
  • Genes, Immediate-Early*
  • Glycogen Synthase Kinase 3 / antagonists & inhibitors
  • Glycogen Synthase Kinase 3 / physiology*
  • Humans
  • Mice
  • Molecular Sequence Data
  • Resting Phase, Cell Cycle / genetics*

Substances

  • CREB1 protein, human
  • Cyclic AMP Response Element-Binding Protein
  • Glycogen Synthase Kinase 3