title: Defining a new role of GW182 in maintaining miRNA stability.
abstract: GW182 binds to Argonaute (AGO) proteins and has a central role in miRNA-mediated gene silencing. Using lentiviral shRNA-induced GW182 knockdown in HEK293 cells, this study identifies a new role of GW182 in regulating miRNA stability. Stably knocking down GW182 or its paralogue TNRC6B reduces transfected miRNA-mimic half-lives. Replenishment of GW182 family proteins, as well as one of its domain Δ12, significantly restores the stability of transfected miRNA-mimic. GW182 knockdown reduces miRNA secretion via secretory exosomes. Targeted siRNA screening identifies a 3'-5' exoribonuclease complex responsible for the miRNA degradation only when GW182 is knocked down. Immunoprecipitation further confirms that the presence of GW182 in the RISC complex is critical in protecting Argonaute-bound miRNA.
authors.affiliation: Department of Oral Biology, University of Florida, Gainesville, Florida 32610-0424, USA.
authors.forename: Bing
authors.initials: B
authors.lastname: Yao
authors.forename: Lan B
authors.initials: LB
authors.lastname: La
authors.forename: Ying-Chi
authors.initials: YC
authors.lastname: Chen
authors.forename: Lung-Ji
authors.initials: LJ
authors.lastname: Chang
authors.forename: Edward K L
authors.initials: EK
authors.lastname: Chan
mesh_terms: D060565:Argonaute Proteins / Q000235:genetics / Q000378:metabolism; D001324:Autoantigens / Q000235:genetics / Q000378:metabolism; D002268:Carboxypeptidases / Q000378:metabolism; D005092:Exonucleases / Q000378:metabolism; D055785:Gene Knockdown Techniques; D057809:HEK293 Cells; D006801:Humans; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism; D020871:RNA Stability / Q000235:genetics; D034741:RNA, Small Interfering; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D060565:Argonaute Proteins; D001324:Autoantigens; D035683:MicroRNAs; D034741:RNA, Small Interfering; D016601:RNA-Binding Proteins; C465663:TNRC6A protein, human; C542384:TNRC6B protein, human; D005092:Exonucleases; D002268:Carboxypeptidases; C436327:SCPEP1 protein, human