Polycomb repressive complex (PRC)-mediated gene silencing is vital for cell identity and development in both the plant and the animal kingdoms. It also modulates responses to stress. Two major protein complexes, PRC1 and PRC2, execute conserved nuclear functions in metazoans and plants through covalent modification of histones and by compacting chromatin. While a general requirement for Polycomb complexes in mitotically heritable gene repression in the context of chromatin is well established, recent studies have brought new insights into the regulation of Polycomb complex activity and recruitment.
PRC2 activity, recruitment, and silencing: a comparative perspective
Highlights
- Polycomb Repressive Complex 2 (PRC2) comprises core and accessory subunits in animals and plants.
- Recent structural insights revealed mechanisms for mammalian PRC2 substrate specificity, and allosteric and competitive inhibition, some of which are likely conserved in plants.
- Different recruitment modes for PRC2 in mammals as opposed to Drosophila and plants suggest that different constraints operate in organisms with larger genomes.
- H3K27me3 deposited by PRC2 is interpreted by reader protein-containing complexes to repress transcription, compact local chromatin, and form long-range loops and Polycomb bodies
Des modes de recrutement différents pour PRC2 suggèrent que des contraintes différentes s'exercent sur des organismes aux génomes plus grands
Via Loïc Lepiniec
'Polycomb' in EntomoNews
https://www.scoop.it/topic/entomonews/?&tag=Polycomb
(4 scoops)