FIGURE 1: Yeast strains deleted for the ubiquitin conjugating enzyme, Ubc1, are impaired for SNF1 kinase-dependent invertase activity expressed from the SUC2 gene. Comparison of invertase activity under repressive (2% glucose) and activating (0.05% glucose) conditions between isogenic yeast strains normalized to WT in 0.05% glucose (value of 100), showing the mean and SD. WT-Snf1-GFP and ubc1Δ-Snf1-GFP have a genomic green-fluorescent protein (GFP) sequence integrated in-frame with the endogenous Snf1 sequence.

(A) Invertase activity after 2 hours of activating growth conditions. Statistical significance based on 3 biological repeats using t-test (Prism 6.0).

(B) Chronological invertase activity of WT and ubc1Δ strains, sampled inter-mittently over 2 hours following shift to low glucose media. Average of four biological repeats with SEM are indicated for each time point.

(C) Agarose gel of RT-PCR products (26 cycles) using primers against SUC2 and rRNA loci from RNA isolated from WT and ubc1Δ strains grown in 2% (H: high) and 0.05% (L: low, 2 hours) glucose.