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The Drosophila MLR COMPASS complex is essential for programming cis-regulatory information and maintaining epigenetic
Claudia B Zraly1, Abdul Zakkar2, John Hertenstein Perez1
1Department of Cancer Biology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL 60153, USA.
Nucleic Acids Research
|February 14, 2020
Summary
The MLR COMPASS complex and its Cmi subunit regulate gene expression by modifying histone marks at enhancers. This epigenetic complex is crucial for both activating and repressing enhancers during animal development.
Area of Science:
- Developmental Biology
- Epigenetics
- Molecular Biology
Background:
- The MLR COMPASS complex monomethylates H3K4, epigenetically marking enhancers for gene expression.
- Proper gene expression is vital for animal development.
Purpose of the Study:
- To investigate the dynamic association of the MLR complex with promoters and enhancers during Drosophila embryogenesis.
- To elucidate the specific roles of the Cmi subunit in enhancer function and epigenetic regulation.
Main Methods:
- Chromatin enrichment analyses in Drosophila embryos.
- RNA interference (RNAi) to deplete the Cmi subunit.
- Analysis of histone modifications (H3K4 monomethylation, H3K27 acetylation).
Main Results:
- MLR complex dynamically associates with promoters and enhancers, with late-stage enrichment at active and poised enhancers.
- Cmi depletion impairs enhancer function and leads to inappropriate activation of hormone-responsive enhancers.
- Cmi is essential for H3K4 monomethylation and H3K27 acetylation but not for Trr binding.
Conclusions:
- The MLR complex plays critical roles in both activating and repressing enhancers based on developmental context.
- MLR complex contributes to enhancer commissioning in early embryogenesis and bookmarking for later reactivation.
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