Chapter Two - Plant Exosomes and Cofactors

Abstract

The exosome is a large protein complex mediating 3'-5' RNA degradation in both nucleus and cytosol of all eukaryotic cells. It consists of nine conserved subunits forming the core complex, which associates with ribonucleolytic enzymes and other cofactors such as RNA-binding proteins or RNA helicases. Both the composition of the core exosome and its general role as a major player in RNA maturation, RNA surveillance, and RNA turnover are largely conserved between plants, human, and fungi. However, plant exosomes have some peculiar and interesting features including a catalytically active core subunit, or a certain extent of functional specialization among both core subunits and putative exosome cofactors.