Related Experiment Video
Updated: Aug 13, 2026

In Vitro Selection of Engineered Transcriptional Repressors for Targeted Epigenetic Silencing
Published on: May 5, 2023
Distinct roles for the essential MYST family HAT Esa1p in transcriptional silencing
Astrid S Clarke1, Eva Samal, Lorraine Pillus
1Division of Biological Sciences, UCSD Cancer Center and Center for Molecular Genetics, University of California-San Diego, La Jolla, CA 92093, USA.
Abstract:
Among acetyltransferases, the MYST family enzyme Esa1p is distinguished for its essential function and contribution to transcriptional activation and DNA double-stranded break repair. Here we report that Esa1p also plays a key role in silencing RNA polymerase II (Pol II)-transcribed genes at telomeres and within the ribosomal DNA (rDNA) of the nucleolus. These effects are mediated through Esa1p's HAT activity and correlate with changes within the nucleolus. Esa1p is enriched within the rDNA, as is the NAD-dependent protein deacetylase Sir2p, and the acetylation levels of key Esa1p histone targets are reduced in the rDNA in esa1 mutants. Although mutants of both ESA1 and SIR2 have enhanced rates of rDNA recombination, esa1 effects are more modest yet result in distinct structural changes of rDNA chromatin. Surprisingly, increased expression of ESA1 can bypass the requirement for Sir2p in rDNA silencing, suggesting that these two enzymes with seemingly opposing activities both contribute to achieve optimal nucleolar chromatin structure and function.
More Related Videos
10:28Repressing Gene Transcription by Redirecting Cellular Machinery with Chemical Epigenetic Modifiers
Published on: September 20, 2018
11:33Investigating Interactions Between Histone Modifying Enzymes and Transcription Factors in vivo by Fluorescence Resonance Energy Transfer
Published on: October 14, 2022
Related Concept Videos
Eukaryotic Transcription Inhibitors
Eukaryotic transcription inhibitors usually contain two distinct domains, a DNA...
RNA Polymerase II Accessory Proteins
Co-activators and Co-repressors
Master Transcription Regulators
Master Transcription Regulators
Epigenetic Regulation