Activation of automethylated PRC2 by dimerization on chromatin.
bioRxiv
; 2023 Oct 13.
Article
em En
| MEDLINE
| ID: mdl-37873121
ABSTRACT
Polycomb Repressive Complex 2 (PRC2) is an epigenetic regulator that trimethylates lysine 27 of histone 3 (H3K27me3) and is essential for embryonic development and cellular differentiation. H3K27me3 is associated with transcriptionally repressed chromatin and is established when PRC2 is allosterically activated upon methyl-lysine binding by the regulatory subunit EED. Automethylation of the catalytic subunit EZH2 stimulates its activity by an unknown mechanism. Here, we show that PRC2 forms a dimer on chromatin in which an inactive, automethylated PRC2 protomer is the allosteric activator of a second PRC2 that is poised to methylate H3 of a substrate nucleosome. Functional assays support our model of allosteric trans-autoactivation via EED, suggesting a novel mechanism mediating context-dependent activation of PRC2. Our work showcases the molecular mechanism of auto-modification coupled dimerization in the regulation of chromatin modifying complexes.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
BioRxiv
Ano de publicação:
2023
Tipo de documento:
Article
País de afiliação:
Estados Unidos