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Updated: Jan 13, 2026
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A Method to Study de novo Formation of Chromatin Domains
Published on: August 23, 2019
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EPOP restricts PRC2.1 targeting to chromatin by directly modulating enzyme complex dimerization
Lihu Gong1,2,3,4, Xiuli Liu1,2,3, Xin Yang1,2,3
1Cecil H. and Ida Green Center for Reproductive Biology Sciences, University of Texas Southwestern Medical Center, Dallas, TX, USA.
Nature Communications
|January 10, 2026
Summary
EPOP protein inhibits Polycomb Repressive Complex 2.1 (PRC2.1) by disrupting its dimer formation, weakening chromatin binding. This regulation is crucial for maintaining epigenetic programs during early cell differentiation.
Area of Science:
- Epigenetics
- Molecular Biology
- Developmental Biology
Background:
- Polycomb Repressive Complex 2 (PRC2) is essential for developmental gene repression.
- PRC2 exists as PRC2.1 and PRC2.2 holocomplexes.
- EPOP is a PRC2.1-specific subunit with a proposed inhibitory role.
Purpose of the Study:
- To elucidate the molecular mechanism of EPOP's regulation of PRC2.1.
- To investigate the role of EPOP-Elongin BC interaction in PRC2.1 inhibition.
- To understand EPOP's function in maintaining epigenetic programs during differentiation.
Main Methods:
- Investigated EPOP's effect on PRC2.1 oligomerization state.
- Assessed PRC2.1 chromatin association.
- Utilized an EPOP mutant defective in PRC2 binding in mouse epiblast-like cells.
- Examined the role of Elongin BC in EPOP-mediated inhibition.
Main Results:
- EPOP directly modulates PRC2.1 oligomerization, disrupting the dimer.
- EPOP weakens PRC2.1 chromatin association by disabling the avidity effect.
- Elongin BC is largely dispensable for EPOP's inhibitory function.
- An EPOP mutant enhanced genome-wide MTF2 enrichments, indicating reduced PRC2.1 activity.
Conclusions:
- EPOP inhibits PRC2.1 by modulating its oligomerization and chromatin binding.
- EPOP defines a unique PRC2.1 subclass important for epigenetic regulation.
- This mechanism prevents over-repression of key developmental regulators during differentiation.
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