Figure 2.

Expression of LmxGT1-GFP (A–D) and LmxGT2-GFP (E–H) as a function of days in culture and in the presence of high (10 mM) or low (0.5 mM) glucose. Each GFP-tagged transporter gene was expressed in a ∆lmxgt1-3 null mutant background. A and E) Cell density for each transgenic null mutant was quantified and plotted as the average of triplicate determinations. glc, glucose. B and F) The rate of uptake of 100 µM [³H]d-glucose by each transgenic line as a function of days of growth and high or low glucose. C and G) Western blot of total lysates probed with anti-GFP antibody. Control represents a cross-reacting band and was used for normalization. Numbers to the left of each blot in this and other figures represent molecular-weight markers (in kilodaltons). D and H) Quantification of the Western blot signal for each GFP fusion protein (protein) and for the corresponding mRNA (RNA). For protein, the intensity of the Western blot signal was normalized to that of the loading control for each sample. RNA was quantified by qRT-PCR of total RNA from each sample and normalized to 18 S rRNA. Samples from day 2 were set to a relative intensity value of 1.0, and other samples were normalized to those on day 2. Culture aliquots used in all panels for A–D and E–H were withdrawn from the same cultures to ensure sample uniformity across different assays.