Phase separation in transcription factor dynamics and chromatin organization.

Studies over the past decade have highlighted the key role of liquid–liquid phase separation in cellular organization and function. Dynamic compartmentalization of transcription factors and coactivators by such phase-separated condensates regulates the assembly of transcriptional machinery at genomic loci. Although rapid advances in microscopy have demonstrated the ubiquity of such condensates, a rigorous characterization of the physics of phase separation in transcription remains to be carried out. In this review, we discuss theoretical and experimental evidence for biomolecular condensates as dynamic regulators of transcription. Looking beyond, we highlight functional consequences for transcription factor dynamics and gene expression and discuss potential pitfalls of misclassifying biomolecular condensates as liquid droplets in the absence of a rigorous physical description. • Liquid–liquid phase separation provides a mechanism for transcriptional regulation • Transcriptional machinery can spontaneously assemble into condensates • Phase separation may regulate genomic organization at all length scales • Liquid condensates can age into gels or solids with different physical properties • Careful characterization of condensates is essential to understand their function [ABSTRACT FROM AUTHOR]