Polycomb group of genes and the epigenetics of aging

Abstract

Polycomb group (PcG) members are the key components of the cellular machinery that maintains the expression state of a large number of genes right from the early development through the entire life span of an individual. This evolutionarily well-conserved group of proteins create and maintain epigenetic chromatin marks that are translated into means of maintaining a temporally and spatially regulated gene expression status. Among the many different targets that PcG regulate are transcripts from Ink4a locus; the gene products of these transcripts being key regulators of cell division and cellular senescence. Additionally, PcG mutations affect self renewal capacity of several stem cells and also interact with another epigenetic chromatin modifier, Sir2, a key negative regulator of aging in yeast and mammals. In this article we bring together the various observations associated with PcG function in the context of cellular senescence and organismal aging.