Model plant study reveals how protein clustering impacts gene regulation and epigenetic silencing

Epigenetic sinenting governs biological processes, from flowering time in plants to prevention of uncontrolled cell growth that leads to cancer in humans.

This fundamental cellular process implies extinguished genes, for example, in response to chemical or environmental effects, initiating changes to the character of cells without modifying the sequence of underlying genes.

If we can understand the detailed molecular mechanisms that are behind epigenetic siles, we can be able to reproduce cultures that develop more effectively and develop therapies that prevent diseases.

The research group of Professor Caroline Dean Frs at John Innes Center has made great progress in this influential field of biological sciences.

Previous research of the group highlighted the importance of a PRC2 protein complex (repressive complex Polycomb 2) to silence the gene of the FLC floral repressor. In plants like Arabidopsis Thaliana, the epigenetic silence of FLC through the winter cold acts as a brake on flowering, which allows the plant to switch to flowering in the spring, a process called varnishing.

In new research published in Molecular cellThe researchers used the Arabidopsis Thaliana model plant to study the functional role of polymerization – a process where proteins form dynamic chain clusters. They focused on two proteins – wine3 and VRN5 – which interact with the PRC2 complex and have shown that the polymerization properties of these proteins are crucial to help extinguish the FLC gene.

This important detail adds to our understanding of the way in which epigenetic siles occurs, and it is part of an emerging image of the regrouping of proteins as a critical theme of gene regulation in plants and animals.

“We show that there is force in number: when the proteins come together, it helps them to keep the DNA packaged – in this case, the region containing the gene which must be extinguished,” explains the first author of the study, Dr Anna Schulten.

“By showing how these proteins work together to silence a key flowering gene, research reveals a new control layer in the way plants react to seasonal changes and offers mechanistic information on gene regulation.”

Although this research relates to plants and can be used to genetically refine the time of flowering in cultures, it also has wider implications because the activity of silence of PRC2 is also found in animals and humans.

In humans, PRC2 anomalies can cause various diseases, including cancer, neurodegenerative disorders and development defects.

The study, a collaboration with the University of York and the MRC LMB in Cambridge, strengthens that plants offer a powerful model to understand the principles of epigenetic processes that can be applied to any life.