The mutant Gap1 proteins display variable uptake activities.

The gap1Δ ura3 strain transformed with the centromere-based plasmids carrying the indicated gap1 alleles were grown on a medium containing galactose as a carbon source and urea as nitrogen source. Uptake activities have been determined by assaying the rates of 14C-citrulline uptake (20 microM). Uptake activities correspond to averages of two independent experiments. Variations did not exceed 20%. Mutant classes: F : functional; NF : non functional; PF : partially functional. Mutated regions: NT: N-terminal tail; CT: C-terminal tail; L2, -4, -6, -10: intracellular loops 2, 4, 6 and 10.