UAS regulatory sequences drive expression of a membrane-tethered form of the Hsap\GCG ligand. The protein consists of Hsap\GCG, a flexible linker containing a Tag:MYC tag, and full-length Nrx-1 (includes the extracellular, transmembrane and cytoplasmic domains). The Hsap\GCG ligand sequence is a mutant form that has a high potency for activation of the Hsap\GCGR receptor.