How does liquid-liquid phase separation contribute to gene regulation?

Biomolecular condensates formed through liquid-liquid phase separation (LLPS) create membraneless organelles that concentrate specific molecules. In gene regulation, transcription factors with intrinsically disordered regions (IDRs) phase separate to form transcriptional condensates at super-enhancers, concentrating the transcription machinery. Mediator and RNA Pol II CTD participate in these condensates. Phase separation also organizes heterochromatin (HP1 condensates), nucleoli (rRNA processing), Cajal bodies, and stress granules. Regulated by post-translational modifications, protein-RNA interactions, and cellular conditions. Disruption of phase separation properties by mutations can cause disease. Experimental approaches include FRAP, optogenetic tools, and in vitro reconstitution. This paradigm adds spatial organization to gene regulation understanding.