Imaging CREB activation in living cells

J Biol Chem. 2010 Jul 23;285(30):23285-95. doi: 10.1074/jbc.M110.124545. Epub 2010 May 18.


The Ca(2+)- and cAMP-responsive element-binding protein (CREB) and the related ATF-1 and CREM are stimulus-inducible transcription factors that link certain forms of cellular activity to changes in gene expression. They are attributed to complex integrative activation characteristics, but current biochemical technology does not allow dynamic imaging of CREB activation in single cells. Using fluorescence resonance energy transfer between mutants of green fluorescent protein we here develop a signal-optimized genetically encoded indicator that enables imaging activation of CREB due to phosphorylation of the critical serine 133. The indicator of CREB activation due to phosphorylation (ICAP) was used to investigate the role of the scaffold and anchoring protein AKAP79/150 in regulating signal pathways converging on CREB. We show that disruption of AKAP79/150-mediated protein kinase A anchoring or knock-down of AKAP150 dramatically reduces the ability of protein kinase A to activate CREB. In contrast, AKAP79/150 regulation of CREB via L-type channels may only have minor importance. ICAP allows dynamic and reversible imaging in living cells and may become useful in studying molecular components and cell-type specificity of activity-dependent gene expression.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • A Kinase Anchor Proteins / metabolism
  • Amino Acid Sequence
  • Animals
  • Biosensing Techniques
  • Calcineurin / metabolism
  • Cell Survival
  • Cyclic AMP Response Element-Binding Protein / chemistry
  • Cyclic AMP Response Element-Binding Protein / metabolism*
  • Cyclic AMP-Dependent Protein Kinases / metabolism
  • HeLa Cells
  • Hippocampus / cytology
  • Humans
  • Molecular Imaging / methods*
  • Neurons / metabolism
  • Phosphorylation
  • Rats
  • Reproducibility of Results


  • A Kinase Anchor Proteins
  • Cyclic AMP Response Element-Binding Protein
  • Cyclic AMP-Dependent Protein Kinases
  • Calcineurin