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Effects of drugs on yeast signaling pathways

Many drugs are used by people without a full knowledge of drug-induced changes in cell function. In this lab, students will screen two drugs for their effect on various metabolic and signaling pathways. The budding yeast Saccharomyces cerevisiae will be used as a test system because of the wealth of knowledge about this eukaryote. Effects of drugs on yeast signaling pathways will be deduced using from the pattern of whole genome mRNA levels, measured by hybridization to DNA microarrays. Two drugs will be tested: one (an azole drug) with a previously characterized genomic response and a second (??) with an unknown response. Possible candidates for the latter drug include crude chemicals from health food stores:

• Echinacea
• St. John's Wort
• Bioflavonoids
• Ginkgo Biloba
• Selenium
• Polyphenols

• Each team will examine the genomic expression profile for yeast treated with fluconazole (an anti-fungal drug).
• One team will examine the genomic expression profile for yeast treated with grape seed extract (gs), which is 95% PROANTHOCYANIDINS.
• One team will examine the genomic expression profile for yeast treated with Chinese green tea extract (GT), which is 50% POLYPHENOLS.

1. Grow yeast overnight in YEPD (a rich growth medium)
2. Dilute ~1 ml O/N culture into 60 mls YEPD (A600=0.1)
3. Grow cells at 30°C in 250 ml flask, with shaking
4. After 4 hours, make sure the cells are in log phase (A600 = 0.2)
5. treat cells for 2 hours as follows:
   • YEPD control (for grape seed or green tea)
   • Ethanol control (for fluconazole)
   • Grape seed extract, 0.5 mg/ml
   • Green tea extract, 0.5 mg/ml
   • Fluconazole (in ethanol), 50 µg/ml
6. Isolate total RNA

PowerPoint Presentations
• Grape Seed Extract
• Chinese Green Tea Extract

Copyright, Acknowledgements, and Intended Use
Created by B. Beason (bbeason@rice.edu), Rice University, 14 March 2005
Updated 21 July 2006