A cAMP Sensor Based on Ligand-Dependent Protein Stabilization

cAMP is a ubiquitous second messenger with many functions
in diverse
organisms. Current cAMP sensors, including Föster resonance
energy transfer (FRET)-based and single-wavelength-based sensors,
allow for real time visualization of this small molecule in cultured
cells and in some cases in vivo. Nonetheless the observation of cAMP
in living animals is still difficult, typically requiring specialized
microscopes and ex vivo tissue processing. Here we used ligand-dependent
protein stabilization to create a new cAMP sensor. This sensor allows
specific and sensitive detection of cAMP in living zebrafish embryos,
which may enable new understanding of the functions of cAMP in living
vertebrates.