UAS regulatory sequences drive expression of a 'morphotrap' fusion protein composed of a Tag:M(Nrt) transmembrane sequence, the Tag:MYC epitope (acts as a spacer), and the VHH(LaG-16) nanobody. The VHH(LaG-16) nanobody is extracellular in the expressed protein, allowing it to trap any GFP-tagged extracellular protein.