Slow Chromatin Dynamics Allow Polycomb Target Genes to Filter Fluctuations in Transcription Factor Activity

• DOI: 10.1016/j.cels.2017.02.013
• Publication Date: 2017-03-22T13:41:43Z
• Authors: Scott Berry; Caroline Dean; Martin Howard
• Keywords: Dynamics; Transcription

Genes targeted by Polycomb repressive complex 2 (PRC2) are regulated in cis chromatin modifications and also trans diffusible regulators such as transcription factors. Here, we introduce a mathematical model which directly antagonizes silencing, thereby linking these cis- trans-regulatory inputs to gene expression. The is parameterized recent experimental data showing that PRC2-mediated accumulate extremely slowly. generates self-perpetuating, bistable active repressed states persist through DNA replication, ensuring high-fidelity transmission of the current state. However, sufficiently strong, persistent activation or repression promotes switching between states. We observe when modification dynamics slow, transient pulses transcriptional effectively filtered, epigenetic memory retained. Noise filtering thus depends on slow may represent an important function PRC2-based regulation.