Figure 1.

Biphasic induction of SUC2. Wild-type (BLY1) cells were grown in glucose (2%) medium to early logarithmic phase, and then quickly shifted to low-glucose (0.05%) medium containing raffinose (2%) unless noted. (A) Biphasic accumulation of SUC2 mRNA. SUC2 transcripts were quantified by real-time PCR in glucose-repressed cells (time 0) and cells induced in low-glucose media with (+ raffinose) or without (− raffinose) raffinose for the indicated times. The levels of SUC2 transcripts were presented as percentages of ACT1 transcripts. (B) Dynamic recruitment of pol II to SUC2. ChIP analysis using anti-pol II CTD antibody was performed on crosslinked chromatin prepared from glucose-repressed or raffinose-induced cells. IP efficiencies of the SUC2 UAS sequence (nucleotides −154 to +45 relative to the translational start site) at different time points were determined by real-time PCR quantitation and presented as the fold increases relative to that at time 0. A semiquantitative multiplex PCR analysis of the precipitated DNA (upper panel) is also shown. A sequence of the ACT1 promoter was co-amplified as an internal control. The PCR products were separated on an 8% polyacrylamide gel and stained with ethidium bromide. (C) Fluctuation of the G1 (unbudded) cell fractions. Cells were withdrawn from a raffinose-induced culture and fixed immediately in 3.7% formaldehyde. The mitotic index was determined microscopically and presented as the percentages of G1 cells.