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Updated: Feb 8, 2026
11:19
Correlating Gene-specific DNA Methylation Changes with Expression and Transcriptional Activity of Astrocytic KCNJ10 Kir4.1
Published on: September 26, 2015
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EPOP and MTF2 activate PRC2 activity through DNA-sequence specificity
Jeffrey Granat1,2, Sanxiong Liu1,2,3,4,5, Luis Popoca1,2
1HHMI, New York University Langone Health, New York, NY 10016.
Summary
The study reveals that EPOP protein enhances Polycomb Repressive Complex 2 (PRC2) histone methyltransferase activity, crucial for gene regulation. EPOP, along with MTF2 and JARID2, promotes H3K27me3 deposition at specific DNA sequences.
Area of Science:
- Epigenetics
- Molecular Biology
- Chromatin Biology
Background:
- Polycomb Repressive Complex 2 (PRC2) is essential for facultative heterochromatin formation and tissue-specific gene expression.
- PRC2 catalyzes histone H3 lysine 27 trimethylation (H3K27me3), a mark targeted by PRC1 for chromatin compaction.
- Cofactors like MTF2 and JARID2 guide PRC2 to specific DNA motifs, regulating its activity.
Purpose of the Study:
- To investigate the role of EPOP in regulating PRC2 activity and H3K27me3 deposition.
- To determine if EPOP influences PRC2 chromatin recruitment or catalytic activity.
- To elucidate the cooperative mechanisms of EPOP, MTF2, and JARID2 in PRC2 function.
Main Methods:
- In vitro histone methyltransferase (HMT) assays to measure PRC2 activity.
- In vivo EED-rescue system to assess PRC2 chromatin recruitment.
- Dinucleosome binding assays to evaluate PRC2-DNA sequence preference.
Main Results:
- EPOP and MTF2 both stimulate PRC2 HMT activity in vitro.
- EPOP does not mediate PRC2 chromatin recruitment in vivo but cooperates with MTF2 and JARID2 for de novo H3K27me3 deposition.
- EPOP enhances PRC2 chromatin binding in a DNA-sequence-dependent manner (GCN-rich sequences).
Conclusions:
- EPOP acts as a positive regulator of PRC2 catalytic activity, distinct from its role in chromatin recruitment.
- EPOP, MTF2, and JARID2 collaborate to promote H3K27me3 deposition at specific DNA sequences, contributing to H3K27me3-chromatin domain formation.
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