File:RNAsilenceOVERVIEW.jpg

Short RNAs derived from Dicer cleavage of dsRNA are incorporated into multiprotein effector complexes, such as RISC and RITS (RNA-induced initiation of TGS) (Verdel et al. 2004) to target mRNA degradation (RNAi/PTGS), translation inhibition, or TGS and genome modifications. ARGONAUTE (AGO) proteins (the name comes from a plant mutant [Bohmert et al. 1998]) bind short RNAs and ‘shepherd’ them to appropriate effector complexes (Carmell et al. 2002). siRNAs originate from perfect RNA duplexes, which can be produced by RDR activity on ssRNA templates; miRNAs originate from imperfect RNA hairpins that are encoded in intergenic regions of plant and animal genomes. Functions are shown at the bottom. In addition to roles in transgene silencing, both TGS and RNAi/PTGS control genome parasites called transposons (Flavell 1994; Plasterk 2002). Genome modifications (DNA and histone methylation) can potentially be targeted by short RNAs that basepair to DNA or to nascent RNA synthesized from the target gene (Grewal and Moazed 2003). Target nucleic acids are shown in blue, short RNAs in red, proteins and enzyme complexes as ovals.

From: Planting the Seeds of a New Paradigm Matzke MA, Matzke AJM PLoS Biology Vol. 2, No. 5, e133 doi:10.1371/journal.pbio.0020133

Planting the Seeds of a New Paradigm

Marjori A. Matzke, Antonius J. M. Matzke

Citation: Matzke MA, Matzke AJM (2004) Planting the Seeds of a New Paradigm. PLoS Biol 2(5): e133 DOI: 10.1371/journal.pbio.0020133

Published: May 11, 2004

Copyright: © 2004 Matzke and Matzke. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.