cAMP effector mechanisms. Novel twists for an 'old' signaling system

FEBS Lett. 2003 Jul 3;546(1):121-6. doi: 10.1016/s0014-5793(03)00563-5.


Cyclic AMP (cAMP) has traditionally been thought to act exclusively through cAMP-dependent protein kinase (cAPK, PKA), but a growing number of cAMP effects are not attributable to general activation of cAPK. At present, cAMP is known also to directly regulate ion channels and the ubiquitous Rap guanine exchange factors Epac 1 and 2. Adding to the sophistication of cAMP signaling is the fact that (1) the cAPK holoenzyme is incompletely dissociated even at saturating cAMP, the level of free R subunit of cAPK being able to regulate the maximal activity of cAPK, (2) cAPK activity can be modulated by oxidative glutathionylation, and (3) cAPK is anchored close to relevant substrates, other signaling enzymes, and local compartments of cAMP. Finally, we will demonstrate an example of fine-tuning of cAMP signaling through synergistic induction of neurite extensions by cAPK and Epac.

Publication types

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

MeSH terms

  • Animals
  • Cyclic AMP / analogs & derivatives
  • Cyclic AMP / metabolism*
  • Cyclic AMP-Dependent Protein Kinases / metabolism
  • Enzyme Activation
  • GTP-Binding Proteins / metabolism
  • Guanine Nucleotide Exchange Factors / metabolism
  • Humans
  • Models, Biological
  • Receptors, Cyclic AMP / metabolism
  • Signal Transduction*


  • Guanine Nucleotide Exchange Factors
  • Receptors, Cyclic AMP
  • Cyclic AMP
  • Cyclic AMP-Dependent Protein Kinases
  • GTP-Binding Proteins