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Published on: August 4, 2019
New mutant versions of yeast FACT subunit Spt16 affect cell integrity
Allyson F O'Donnell1, Jennifer R Stevens, Rosemarie Kepkay
1Department of Biochemistry and Molecular Biology, Dalhousie University, Sir Charles Tupper Medical Building, 5850 College Street, Halifax, NS, B3H 1X5, Canada.
Molecular Genetics and Genomics : MGG
|September 4, 2009
Summary
FACT, a transcription factor, plays a crucial role in DNA transcription. New Spt16 FACT subunit mutants reveal its unexpected involvement in maintaining yeast cell integrity.
Area of Science:
- Molecular Biology
- Genetics
- Cell Biology
Background:
- Transcription by RNA polymerase II is hindered by nucleosomes.
- The FACT (Facilitates Chromatin Transcription) complex modulates transcription at various stages.
- FACT's roles include facilitating TATA-binding factor at promoters and managing nucleosome structure during elongation.
Purpose of the Study:
- To identify new mutant versions of the Spt16 subunit of yeast FACT.
- To investigate the effects of these mutants on transcription fidelity and cell integrity.
- To explore the relationship between FACT and cell integrity pathways.
Main Methods:
- Utilized reporter genes to screen for FACT mutants affecting transcription fidelity.
- Generated and analyzed spt16 mutant alleles in yeast.
- Assessed cell integrity phenotypes including temperature sensitivity, detergent sensitivity, and morphology.
- Investigated interactions with the ssd1-d mutation and protein kinase C (Pkc1) signaling pathway.
Main Results:
- Identified novel spt16 mutant alleles with dominant negative effects on transcription initiation fidelity.
- Discovered that two spt16 mutant alleles also impact cell integrity, causing temperature sensitivity, altered detergent sensitivity, and abnormal morphology.
- Found that these spt16 mutant phenotypes are exacerbated by the ssd1-d mutation.
- Demonstrated that Pkc1 signaling pathway components modulate the spt16 ssd1-d temperature sensitivity, indicating functional overlap.
Conclusions:
- The FACT subunit Spt16 is unexpectedly involved in the maintenance of cell integrity.
- FACT and Pkc1 signaling pathways share overlapping essential functions.
- Altered FACT activity can have pleiotropic effects beyond transcription, impacting cellular homeostasis.
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