Exponential cultures (in YPGal medium) of W303-1A, UBHY-R, and UBHY-R strains transformed with p414GAL1 vectors encoding human eIF5A-1 wild type or mutant proteins K47A, K47R, and K50R were washed with water, resuspended in YPD medium at the density of ~0.125 (OD 600 nm) and growth was followed for 5 h (A). At 0, 1, 3, and 5 h after shift to the glucose medium, aliquots of cells were used to measure protein synthesis as described under Experimental Procedures and the rate of protein synthesis was calculated for each sample as dpm/μg/20 min (B). The levels of human and yeast eIF5A and yeast UBR5A proteins were determined by western blot analysis (C). The experiments were repeated two to three times with virtually the same results: a typical experiment is shown.