Fig. 7. The ZAP1-1^up mutation turns on a quiescent activation domain. (A) ZAP1-1^up retains zinc-responsive regulation. Wild-type (DY1457) and ZAP1-1^up (ZHY7) strains bearing pDg2 were grown to exponential phase in SD media (+) or in SD media that had been supplemented with 1 mM EDTA, 100 µM ZnCl₂ (–) or 100 µM ZnCl₂ alone (++) prior to β-galactosidase activity assays. (B) The ZAP1-1^up allele contains an activation domain not present in the wild-type protein. Strain DEY1538 (zap1 gal4 gal80) containing the GAL1-lacZ reporter (pRY171) and either the vector (pMA424), pGBD–Zap1_1–331 or pGBD Zap1-1^up_1–331 was grown to exponential phase in LZM supplemented with either 5 µM (–Zn) or 1000 µM (+Zn) ZnCl₂ prior to β-galactosidase assay. The asterisk denotes the mutation in the Zap1-1^up allele. Representative experiments are shown.