Figure 1.

Schematic representation of the assay systems for in vivo transcriptional activation by Res2–Cdc10–Rep2. (A) Assays for transcription activation by Res2–Cdc10–Rep2 were carried out with a Δswi6 strain of S. cerevisiae and a single copy of a reporter gene whose promoter contains two or three MCB elements. Res2 by itself would not activate reporter gene, whereas the Res2–vp16–Cdc10 complex would. Res2–Cdc10 would have no or very low transcriptional activity, but coexpression of Rep2 with Res2–Cdc10 is expected to activate the reporter gene. (B) Structure of reporter genes in Δ178.3 MluI-LacZ, the promoter of S. cerevisiae CYC1 (−1 ∼ −178) containing exogenously inserted triple MluI sequences (MCB element) is fused with the LacZ coding sequence. In TMP-HIS3, the S. cerevisiae TMP promoter (−1 ∼ −166) containing two endogenous MCB motifs at −159 and −122 is ligated to the S. cerevisiae His3 coding sequence.