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)), a modified carboxy terminus of cac (the PDZ binding sites and Cam binding domain in the cac sequence has been scrambled) and the PDZ domain and SH3 binding motif of Rim. The configuration of the fusion protein results in the FAPα2 sequence and epitope tags being extracellular, while the cac and Rim sequences are intracellular.