Polycomb-group proteins play a central role in remodelling chromatin, marking genes for epigenetic silencing.
Polycomb proteins are a group of proteins which are involved in genome regulation. Polycomb-group proteins hold DNA loops in close proximity in the nucleus. These DNA sections can be from very different regions on the genome. Polycomb-group proteins specifically act to rearrange the DNA in the nucleus to enable the epigenetic silencing, or “turning off”, of genes.
Polycomb group proteins have been shown to have tumour suppressor activity. That is to say, they act to prevent the formation of tumours. In particular, this includes binding to, and silencing, genes involved in the control of cell growth (proliferation), cell signalling and call polarity.
This illustration was made in response to research by Giacomo Cavalli.