RNA polymerase I in yeast transcribes dynamic nucleosomal rDNA
Hannah S Jones1, Junya Kawauchi, Priscilla Braglia
1Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK.
Active ribosomal DNA (rDNA) in yeast contains nucleosomes and dynamic chromatin structures, challenging previous assumptions. Chromatin remodelers are crucial for proper transcription termination of these genes.
Area of Science:
- Molecular Biology
- Yeast Genetics
- Chromatin Biology
Background:
- Budding yeast ribosomal DNA (rDNA) exists as tandem repeats, with half inactivated by repressive chromatin.
- Active rDNA is transcribed by RNA polymerase I (Pol I) elongation complexes.
- Previous studies suggested active rDNA lacks nucleosomal structure.
Purpose of the Study:
- To investigate the nucleosomal structure of actively transcribed rDNA.
- To identify chromatin-remodeling enzymes associated with active rDNA transcription.
- To understand the role of chromatin structure in Pol I transcription.
Main Methods:
- Chromatin immunoprecipitation (ChIP).
- Biochemical fractionation.
- Analysis of yeast strains with reduced rDNA repeat numbers.
Main Results:
- Active rDNA possesses nucleosomal structure, contrary to prior beliefs.
- Actively transcribed rDNA exhibits a dynamic chromatin structure with unphased nucleosomes.
- Chromatin remodelers Chd1p, Isw1p, and Isw2p are associated with active rDNA.
- Inactivation of these remodelers leads to transcription termination defects.
Conclusions:
- Actively transcribed rDNA is organized into nucleosomes.
- Dynamic chromatin structures and remodeling enzymes play a role in Pol I transcription.
- Pol I transcription regulation may involve mechanisms similar to Pol II transcription.
More Related Videos
09:15Monitoring Protein-RNA Interaction Dynamics In Vivo at High Temporal Resolution Using χCRAC
Published on: May 9, 2020
09:21Saccharomyces cerevisiae Metabolic Labeling with 4-thiouracil and the Quantification of Newly Synthesized mRNA As a Proxy for RNA Polymerase II Activity
Published on: October 22, 2018
Related Concept Videos
Eukaryotic RNA Polymerases
All three eukaryotic RNAPs require specific transcription factors, of which the...
Eukaryotic RNA Polymerases
All three eukaryotic RNAPs require specific transcription factors, of which the...
Transcription Initiation
The promoters and enhancers and their accessory proteins allow tight regulation of...
Bacterial RNA Polymerase
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...
Bacterial RNA Polymerase
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...
Transcription Elongation Factors
The transcription elongation is regulated via pausing of RNA polymerase on several occasions during transcription. In bacteria, these halts are necessary because the transcription of DNA into mRNA is coupled to the translation of that mRNA into a...
