Fig. 1

System design of AAV-based dual reporters for monitoring cell signaling. a Visualization and quantification of cell signaling with GFP and firefly luciferase (Luc). Cell signaling is illustrated as sequential events, including the increase in amount of signaling molecule, binding of signaling molecule to its receptor, signaling transduction, activation of transcription factor (TF), and final activations of reporter genes (GFP and Luc). b Schematic illustration of dual-reporter design and construction. Specific signaling reporters can be constructed by inserting the transcription factor responding elements (TRE) immediately upstream of the minimal CMV promoter (mCMV). These cell-signaling specific reporters can trace transcription activities in mammalian cells depending on the status of TFs with minimal expression of reporters in the absence of TFs (upper panel) and a high expression of the reporters upon the activation of TFs (lower panel)