VEL-dependent polymerization maintains the chromatin association of Polycomb proteins for the switch to epigenetic silencing.

ABSTRACT: Multivalent protein-chromatin interactions facilitated by higher-order protein assemblies are emerging as a crucial theme in eukaryotic gene regulation. However, understanding the underlying mechanisms in their functional context remains challenging. Arabidopsis VEL proteins assemble biomolecular condensates by head-to-tail polymerization. Here, we dissect the role of VEL polymerization domains in conferring the epigenetic switch to Polycomb repressive complex 2 (PRC2) silencing at Arabidopsis FLOWERING LOCUS C (FLC). We show that VIN3 VEL polymerization produces higher-order nuclear VIN3 assemblies in vivo, which promote multivalent chromatin association and efficient H3K27me3 nucleation. VRN5 VEL polymerization, however, is not required unless a third homolog VEL1 is absent. The VRN5 VEL

SUBMITTER: Schulten A 

PROVIDER: S-EPMC7618248 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature