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Updated: Jul 5, 2026
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Repressing Gene Transcription by Redirecting Cellular Machinery with Chemical Epigenetic Modifiers
Published on: September 20, 2018
Active gene repression by the Egr2.NAB complex during peripheral nerve myelination
Gennifer M Mager1, Rebecca M Ward, Rajini Srinivasan
1Molecular and Cellular Pharmacology Training Program, Department of Comparative Biosciences, Graduate Program in Cellular and Molecular Biology, University of Wisconsin, Madison, WI 53706, USA.
The Journal of Biological Chemistry
|May 6, 2008
Summary
The Egr2 transcription factor, with NAB corepressors, directly represses specific genes during peripheral nerve myelination. This novel repression mechanism helps coordinate myelin formation and gene expression.
Area of Science:
- Neuroscience
- Molecular Biology
- Gene Regulation
Background:
- Egr2 (Krox20) is crucial for peripheral nerve myelination by Schwann cells, primarily known for activating myelin-associated genes.
- Emerging evidence suggests Egr2 also plays a role in gene repression during myelination.
- NAB (NGFI-A/Egr-binding) corepressors interact with Egr2 and are essential for coordinating myelin formation.
Purpose of the Study:
- To investigate the physiological role of NAB corepression in Egr2-mediated gene repression during peripheral nerve myelination.
- To determine if the Egr2.NAB complex directly represses specific target genes involved in myelination.
Main Methods:
- Screening for NAB-regulated genes during peripheral nerve myelination.
- In vivo chromatin immunoprecipitation (ChIP) analysis in myelinating sciatic nerves.
- Assessing the interaction of NAB2 with CHD4 and its role in chromatin remodeling.
Main Results:
- Identified Id2, Id4, and Rad as NAB-regulated genes that decrease during myelination.
- Demonstrated developmental association of Egr2 and NAB2 on the promoters of Id2, Id4, and Rad during their repression.
- Showed NAB2 represses transcription via interaction with CHD4, a component of the nucleosome remodeling and deacetylase complex, which occupies repressed promoters.
Conclusions:
- Egr2 directly represses genes during peripheral nerve myelination through collaboration with NAB corepressors, revealing a novel regulatory mechanism.
- Repression of Id2 expression was shown to enhance the activation of Mpz (myelin protein zero) expression.
- This study elucidates a new facet of genetic regulation in peripheral nerve myelination involving coordinated gene activation and repression.
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