How Polycomb-Mediated Cell Memory Deals With a Changing Environment: Variations in PcG Complexes and Proteins Assortment Convey Plasticity to Epigenetic Regulation as a Response to Environment

by Federica Marasca, Beatrice Bodega, Valerio Orlando
Year: 2018 DOI: 10.1002/bies.201700137

Extra Information

Bioessays. 2018 Apr;40(4):e1700137. doi: 10.1002/bies.201700137. Epub 2018 Mar 9


Cells and tissues are continuously exposed to a changing microenvironment, hence the necessity of a flexible modulation of gene expression that in complex organism have been achieved through specialized chromatin mechanisms. Chromatin-based cell memory enables cells to maintain their identity by fixing lineage specific transcriptional programs, ensuring their faithful transmission through cell division; in particular PcG-based memory system evolved to maintain the silenced state of developmental and cell cycle genes. In evolution the complexity of this system have increased, particularly in vertebrates, indicating combinatorial and dynamic properties of Polycomb proteins, in some cases even overflowing outside the cell nucleus. Therefore, their function may not be limited to the imposition of rigid states of genetic programs, but on the ability to recognize signals and allow plastic transcriptional changes in response to different stimuli. Here, we discuss the most novel PcG mediated memory functions in facing and responding to the challenges posed by a fluctuating environment.


PRC2 PcG proteins adaptation environmental changes epigenetic memory evolution plasticity