The polycomb group (PcG) is a family of proteins required for proper eukaryotic gene expression that determines cell fate (epigenetics, epigenetic gene silencing). They exert their role mainly by repressing gene transcription through epigenetic modifications on specific histone tails that are inherited through cell divisions, thus functioning as the cellular memory. They are involved in the maintenance of cell type and differentiation and play a role in tumor development.
Cell differentiation depends upon keeping certain genes “on” and other genes “off” through generations. The differential gene expression patterns that define a cell type are maintained during DNA replication and at mitosis so that the daughter cells maintain the differentiated cell type of the parental cell. This is possible because cells have a transcriptional memory. Perturbance of the transcriptional memory can lead to severe developmental defects and to malignancy. The molecular basis of...
KeywordsHomeotic Gene Polycomb Group Stem Cell Maintenance Fibroblast Growth Factor Family Transcriptional Memory
- Sparmann A, van Lohuizen M (2006) Polycomb silencers control cell fate development and cancer. Nature 6:846–856Google Scholar