CRE DD Green Reporter System

DD-Fluorescent Protein promoter reporters provide a much greater fold increase in signal intensity than traditional fluorescent protein reporters, which do not contain the DD

DD-Fluorescent Protein promoter reporters provide a much greater fold increase in signal intensity than traditional fluorescent protein reporters, which do not contain the DD. HEK 293 cells were transfected with plasmids encoding the following reporters: CRE-tdTomato, CRE-DD-tdTomato, CRE-ZsGreen1, and CRE-DD-ZsGreen1. 24 hr later, the cells were stimulated with 10 μM forskolin and simultaneously treated with 1 μM Shield1. After 4.5 hr, fluorescence intensity was measured via flow cytometry, and fold induction was calculated. The tdTomato and ZsGreen1 reporters containing the DD had three- and six-fold greater fluorescence intensity respectively, than the versions without the DD, due to the latter’s increased background levels.

Ligand-dependent, targeted, and reversible fluorescent protein reporter stabilization

Ligand-dependent, targeted, and reversible fluorescent protein reporter stabilization. A small destabilization domain (DD) is fused to the fluorescent protein reporter. The small membrane-permeant ligand Shield1 binds to the DD and protects the entire fusion protein from proteasomal degradation. Removal of Shield1, however, causes rapid degradation of the entire DD-fluorescent protein reporter. The default pathway for the DD-Fluorescent Protein Reporter Systems is degradation of the DD-fluorescent protein reporter, assuring low background, unless Shield1 is present, assuring low background.