Polycomb group PcG proteins PRC1 PRC2 Pho-complex Mechanisms of inactivation of gene expression TrxG complex components PcG/TrxG response elements Nuclear architecture Open questions Glossary Cited literature Polycomb group PcG proteins Polycomb group (PcG) proteins generally maintain gene repression, whereas Trithorax group (TrxG) proteins maintain the active gene expression.
PcG and TrxG proteins were initially isolated in Drosophila as factors involved in maintaining the expression patterns of HOX genes, which encode transcription factors that are important determinants of patterning during embryonic development.