Enzyme assay with duplicate fluorophores

A reporting construct for performing an assay for a first enzyme activity comprising:

• a membrane anchoring domain comprising a first peptide that forms a complex with a membrane of a cell, wherein the cell comprises cytoplasm that includes a protease;
• a reporter domain comprising a first occurrence of a second peptide that produces a first signal at a first wavelength and a second occurrence of the second peptide that produces a second signal at the first wavelength, wherein the reporter domain produces an aggregate signal comprising an intensity that is a summation of intensity of the first signal and intensity of the second signal;
• a third peptide comprising a cleavage site, the third peptide interposed between the membrane anchoring domain and the reporter domain, wherein the third peptide is selected to undergo a cleavage event at the cleavage site upon exposure to the first enzyme activity,
• wherein the second peptide is susceptible to proteolysis in cytoplasm of the cell by the protease within a period of time encompassed by the assay, wherein said proteolysis results in an observable reduction in the aggregate signal as a function of the first enzyme activity, and wherein fragmentation of one of the first or second occurrences of the second peptide due to said proteolysis provides a decrease in the aggregate signal wherein the membrane anchoring domain is coupled to an auxiliary reporting domain that provides a signal at a second wavelength, wherein the second wavelength is distinguishable from the first wavelength, and wherein the auxiliary reporting domain remains localized with the cell membrane following the cleavage event.