Related Experiment Videos
Multiple signals regulate GAL transcription in yeast
J R Rohde1, J Trinh, I Sadowski
1Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, Canada.
Molecular and Cellular Biology
|May 11, 2000
Summary
Gal4p phosphorylation by Srb10p/CDK8 is crucial for sensitive GAL gene induction in yeast. This mechanism works in parallel with Gal3p, providing a dual control system for gene activation.
Area of Science:
- Molecular Biology
- Yeast Genetics
- Transcriptional Regulation
Background:
- Gal4p is a transcription factor regulating Saccharomyces GAL genes.
- Gal4p interacts with the RNA polymerase II (Pol II) holoenzyme and undergoes phosphorylation.
- Srb10p/CDK8, part of the Pol II holoenzyme mediator, phosphorylates Gal4p.
Purpose of the Study:
- To investigate the role of Gal4p phosphorylation at S699 in GAL gene induction.
- To elucidate the mechanisms controlling Gal4p activity in response to galactose.
- To understand the interplay between Gal3p and Srb10p in GAL gene regulation.
Main Methods:
- Analysis of Gal4p phosphorylation at S699.
- Genetic studies in Saccharomyces cerevisiae strains.
- Investigating the function of Srb10p/CDK8 and Gal3p in GAL gene induction.
Main Results:
- Gal4p phosphorylation at S699 by Srb10p/CDK8 is essential for full GAL gene induction.
- This phosphorylation is necessary for a sensitive response to galactose.
- Gal4p S699 phosphorylation occurs independently of Gal3p and contributes to adaptation.
- SRB10 and GAL3 function in parallel pathways for GAL gene induction.
Conclusions:
- Gal4p activity is regulated by two independent signals: Gal3p-galactose and Srb10p/CDK8.
- Srb10p/CDK8 phosphorylation provides a mechanism for coordinating inducer response with environmental cues.
- CDK8 may play a role in modulating the phosphorylation of gene-specific activators.