title: Variations on a theme: Polycomb group proteins in plants.
abstract: Polycomb group (PcG) proteins evolved early in evolution, probably in the common ancestor of animals and plants. In some unicellular organisms, such as Chlamydomonas and Tetrahymena, PcG proteins silence genes in heterochromatin, suggesting an ancestral function in genome defence. In angiosperms, the PcG system controls many developmental transitions. A PcG function in the vernalization response evolved especially in Brassicaceaea. Thus, the role of PcG proteins has changed during evolution to match novel needs. Recent studies identified many proteins associated with plant PcG protein complexes. Possible functions of these interactions are discussed here. We highlight recent findings about recruitment of PcG proteins in plants in comparison with animal system. Through the new data, a picture emerges in which PcG protein complexes do not function in sequential linear pathways but as dynamically interacting networks allowing stabilizing feedback loops. We discuss how the interplay between different PcG protein complexes can enable establishment, maintenance, and epigenetic inheritance of H3K27me3.
authors: Department of Plant Biology and Forest Genetics, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, SE-75007 Uppsala, Sweden Department of Biology and Zurich-Basel Plant Science Center, ETH Zurich, CH-8092, Zurich, Switzerland.
authors: Maria
authors: M
authors: Derkacheva
authors: Department of Plant Biology and Forest Genetics, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, SE-75007 Uppsala, Sweden Department of Biology and Zurich-Basel Plant Science Center, ETH Zurich, CH-8092, Zurich, Switzerland Science for Life Laboratory, SE-75007 Uppsala, Sweden Lars.Hennig@slu.se.
authors: Lars
authors: L
authors: Hennig
mesh_terms: D044127:Epigenesis, Genetic; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D063146:Polycomb-Group Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D010940:Plant Proteins; D063146:Polycomb-Group Proteins
keywords: Chromatin; Polycomb group proteins.; epigenetics; gene silencing; plants