Figure 5.

The Cln2 and Cln3 degrons activate transcription in yeast. (A) Structure of the GAL4–Cln2 and –Cln3 activators. (B) Activation of His3p expression. The indicated GAL4-fusion proteins were expressed in yeast strain HF7c, and their ability to activate transcription was scored by yeast growth in the presence of 3AT. Yeast were grown either in media containing histidine (nonselective; Left) or media lacking histidine and containing 2 mM 3AT (selective media; Right). (C) Activation of β-galactosidase (β-gal) expression. Liquid cultures of HF7c cells carrying an empty expression vector (−) or vectors expressing the indicated GAL4–fusion proteins were assayed for β-gal expression as described in Materials and Methods. Relative β-gal activity is expressed relative to β-gal activity directed by the GAL4 DBD alone (Δ), which is set at 1.