Metabolic Fate of the Increased Yeast Amino Acid Uptake Subsequent to Catabolite Derepression
Figure 1
(a) L-[14C]leucine (750 μM) oxidation in WT and amino acid permease deleted yeast strains. Yeast was grown in either 2% glucose (filled bars) or 2% galactose (hollow bars). L-[14C]leucine uptake and oxidation were performed as described in Materials and Methods. Deletion of various amino acid permeases (M4055 : MATa ura3 gap1 D D(bap2-tat1), M4581: MATa ura3 gap1D agp1D gnp1D D(bap2-tat1), M4582: MATa ura3 gap1D D(bap2-tat1) bap3D tat2D) from the WT (M3750) reduced the rate of L-[14C]leucine oxidation observed when yeast are grown in galactose. Results are mean ± SEM from 3 different preparations each measured in quadruplicate. (b) Correlation between carbon catabolite derepressed L-leucine uptake (shaded bars) and oxidation (hatched bars). For correlation analysis data (nmol/million cells/h), oxidation () and uptake () in the WT M3750 strain were normalized to 1. In deleted strains bars represent the proportion of either uptake or oxidation observed in the WT strain.
