31 Harbeck, M. C. Chepurny, O. Nikolaev, V. O. Lohse, M. J. Holz, G. G. Roe, M. W. 2006 Sci STKE 2006 353 pl6 Sep 19 1525-8882 (Electronic) 16985238 Transfection Second Messenger Systems Reproducibility of Results Recombinant Proteins/biosynthesis Mice Calcium/*analysis *Biosensing Techniques Animals Guanine Nucleotide Exchange Factors/genetics Fura-2 Fluorescent Dyes Fluorescence Resonance Energy Transfer/methods Cytosol/*chemistry Cyclic AMP/*analysis Cell Line, Tumor Cations, Divalent Cell Line Tumor Cations Divalent Understanding the temporal and spatial integration of the Ca2+ and adenosine 3',5'-monophosphate (cAMP) signaling pathways requires concurrent measurements of both second messengers. Here, we describe an optical technique to simultaneously image cAMP and Ca2+ concentration gradients in MIN6 mouse insulinoma cells using Epac1-camps, a Forster (or fluorescence) resonance energy transfer (FRET)-based cAMP biosensor, and Fura-2, a fluorescent indicator of Ca2+. This real-time imaging method allows investigation of the dynamic organization and integration of multiple levels of signal processing in single living cells. Journal ArticleUnited Statessignal transduction knowledge environment http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=16985238