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cAMP effector mechanisms. Novel twists for an ‘old’ signaling system
Author(s) -
Kopperud Reidun,
Krakstad Camilla,
Selheim Frode,
Døskeland Stein Ove
Publication year - 2003
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(03)00563-5
Subject(s) - effector , protein kinase a , protein subunit , microbiology and biotechnology , signal transduction , biology , chemistry , kinase , biochemistry , gene
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.