UAS regulatory sequences drive expression of a fusion protein composed of the Tag:SS(wg) signal peptide, a Tag:HA epitope, the FAPα2 fluorogen-activating peptide, a Tag:MYC epitope, a transmembrane domain (Tag:TM(hPDGFRB)) and a modified carboxy terminus of PMCA (the Cam binding site in the PMCA sequence has been scrambled to prevent unwanted oligomerization or cleavage by calpains). The configuration of the fusion protein results in the FAPα2 sequence and epitope tags being extracellular, while the PMCA sequence is intracellular (as in the endogenous PMCA protein).