Genetic interactions between an RNA polymerase II phosphatase and centromeric elements in Saccharomyces cerevisiae
1Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-3202, USA.
Molecular Genetics and Genomics : MGG
|May 11, 2004
Summary
Centromeric DNA can suppress mutations in the essential Saccharomyces cerevisiae gene FCP1, affecting RNA polymerase II phosphorylation. This suggests a novel regulatory role for centromeres in transcription.
Area of Science:
- Molecular Biology
- Yeast Genetics
- Gene Regulation
Background:
- The Saccharomyces cerevisiae protein phosphatase Fcp1, encoded by the essential gene FCP1, is crucial for regulating transcription by RNA polymerase II.
- Mutations in FCP1 can lead to temperature-sensitive phenotypes, indicating its vital role in cellular processes.
Purpose of the Study:
- To identify genes that can suppress the temperature-sensitive defects of fcp1-2 and fcp1-4 phosphatase mutants.
- To investigate the role of centromeric DNA in suppressing fcp1 mutations and its effect on RNA polymerase II phosphorylation.
Main Methods:
- A multicopy suppressor screen was performed on fcp1-2 and fcp1-4 yeast mutants.
- Suppression was assessed by complementation of the temperature-sensitive phenotype.
- The effect of suppressor centromeres on Fcp1 protein levels and RNA polymerase II phosphorylation was analyzed.
Main Results:
- Wild-type FCP1 suppressed the fcp1-4 mutation, while three second-site suppressors were found for fcp1-2.
- Two suppressors for fcp1-2 mapped to centromere regions, with suppression dependent on the CDEIII region.
- Suppressor centromeres altered Fcp1 protein levels and RNA polymerase II phosphorylation in fcp1-2 cells.
Conclusions:
- Centromeric DNA, particularly the CDEIII region, can functionally suppress defects in the essential FCP1 gene.
- Centromeric DNA influences Fcp1 protein levels and RNA polymerase II phosphorylation, suggesting a regulatory role in transcription.
- Genetic interactions with centromere-binding proteins (SKP1, CEP3, CBF1) further support the link between centromeres and Fcp1 function.
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