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Repressing Gene Transcription by Redirecting Cellular Machinery with Chemical Epigenetic Modifiers
Published on: September 20, 2018
Stage-specific repression by the EKLF transcriptional activator
Xiaoyong Chen1, James J Bieker
1Mount Sinai School of Medicine, Brookdale Department of Molecular, Cell and Developmental Biology, Box 1020, One Gustave L. Levy Place, New York, NY 10029, USA.
Molecular and Cellular Biology
|November 16, 2004
Summary
Transcription factor Erythroid Kruppel-like factor (EKLF) dynamically switches between activating and repressing gene expression. Its interaction with coactivators and corepressors, like Sin3A, is regulated by cell stage and acetylation.
Area of Science:
- Molecular Biology
- Gene Regulation
- Epigenetics
Background:
- Transcription factor function is modulated by dynamic interactions with coactivators and corepressors.
- Erythroid Kruppel-like factor (EKLF) is crucial for beta-globin gene activation in erythroid cells.
- EKLF interacts with both activating (CBP/p300, SWI/SNF) and repressing (Sin3A, HDAC1) protein complexes.
Purpose of the Study:
- To investigate how EKLF switches between transcriptional activation and repression.
- To elucidate the role of EKLF's zinc finger domain and post-translational modifications in its interactions.
- To understand the stage-specific regulation of EKLF activity during erythroid differentiation.
Main Methods:
- Site-directed mutagenesis to create EKLF point mutants.
- Co-immunoprecipitation assays to study protein-protein interactions.
- Analysis of EKLF acetylation and its impact on coactivator/corepressor binding.
Main Results:
- Selected point mutants uncoupled EKLF's activation and repression functions.
- An intact zinc finger structure was not essential for Sin3A/HDAC1 interaction or transrepression.
- EKLF repression displayed stage specificity, mediated by reversible EKLF-Sin3A interactions.
- A specific lysine residue on EKLF was identified as a target for CBP acetylation and required for Sin3A interaction.
Conclusions:
- Erythroid cell differentiation stage influences EKLF acetylation status.
- Acetylation status dictates EKLF's interaction with coactivators versus corepressors.
- This dynamic switching mechanism controls downstream transcriptional effects during erythropoiesis.
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