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Published on: August 9, 2019
Shields up: the Tup1-Cyc8 repressor complex blocks coactivator recruitment
Emily J Parnell1, David J Stillman
1Department of Pathology, University of Utah Health Sciences Center, Salt Lake City, Utah 84112, USA.
Genes & Development
|December 14, 2011
Summary
The Tup1-Cyc8 complex in yeast acts as a shield, preventing DNA-binding proteins from recruiting transcriptional coactivators, challenging prior models of its corepressor function.
Area of Science:
- Molecular Biology
- Yeast Genetics
- Gene Regulation
Background:
- The Tup1-Cyc8 complex is known to repress gene expression in Saccharomyces cerevisiae.
- Previous models proposed Tup1-Cyc8 functions as a corepressor, actively organizing chromatin and interacting with regulatory proteins to block transcription.
Purpose of the Study:
- To re-evaluate the mechanism by which the Tup1-Cyc8 complex represses gene expression.
- To challenge the established 20-year-old models of Tup1-Cyc8 function.
Main Methods:
- The study involved experiments on Saccharomyces cerevisiae.
- Investigated the interaction of Tup1-Cyc8 with DNA-binding proteins and transcriptional coactivators.
Main Results:
- Demonstrated that Tup1-Cyc8 primarily functions as a shield.
- This shielding mechanism blocks DNA-binding proteins from recruiting transcriptional coactivators, rather than through direct chromatin organization.
Conclusions:
- The findings challenge the predominant view of Tup1-Cyc8 as a corepressor.
- Suggests a novel mechanism of transcriptional repression mediated by Tup1-Cyc8 acting as a physical barrier.
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