Abstract 2238 Regulation and function of heterochromatin compartments

Nuclear phase separation has been proposed to play a role in the functional organization of the genome. This novel perspective offers innovative avenues for addressing longstanding questions in genome biology. However, the mechanisms governing phase separation and its associated functions continue to be the subject of intense debate. I will discuss our recent work that explores the mechanisms and function of condensate formation by the heterochromatin protein 1 (HP1). HP1 is a key component of constitutive heterochromatin, important for gene silencing, DNA compaction, and genome stability. In cells, HP1 form dynamic puncta in cells. The mechanisms regulating the subcellular localization of HP1 are largely unknown. Further, the importance of HP1 phase separation for cellular function remains unclear. I will present results from a genetic screen that identified regulators of HP1 compartments and I will propose a revised model for heterochromatin regulation and function.