HP1α oligomeric state modulates Heterochromatin 3D organization: Insights from a polymer model

While our understanding of heterochromatin’s nanostructure and its role in gene silencing is evolving, it remains nuanced. In this study, we propose a polymer model of HP1α with multiple domains and chromatin at the nucleosome level. This model enabled a detailed exploration of chromatin architecture, revealing a unique nucleosome organization modulated by HP1α's oligomeric states. Specifically, HP1α monomers establish a distinct nucleosome spacing throughout the genome and this spacing becomes locally condensed upon HP1α dimerization. Verification via Förster resonance energy transfer (FRET) microscopy reaffirms our findings. Therefore, our findings provide pivotal insights into the mechanisms of heterochromatin formation and preservation.