title: Molecular characterization of human Argonaute-containing ribonucleoprotein complexes and their bound target mRNAs.
abstract: microRNAs (miRNAs) regulate the expression of mRNAs in animals and plants through miRNA-containing ribonucleoprotein particles (RNPs). At the core of these miRNA silencing effector complexes are the Argonaute (AGO) proteins that bind miRNAs and mediate target mRNA recognition. We generated HEK293 cell lines stably expressing epitope-tagged human AGO proteins and other RNA silencing-related proteins and used these cells to purify miRNA-containing RNPs. Mass spectrometric analyses of the proteins associated with different AGO proteins revealed a common set of helicases and mRNA-binding proteins, among them the three trinucleotide repeat containing proteins 6 (TNRC6A,-B,-C). mRNA microarray analyses of these miRNA-associated RNPs revealed that AGO and TNRC6 proteins bind highly similar sets of transcripts enriched in binding sites for highly expressed endogenous miRNAs, indicating that the TNRC6 proteins are a component of the mRNA-targeting miRNA silencing complex. Together with the very similar proteomic composition of each AGO complex, this result suggests substantial functional redundancy within families of human AGO and TNRC6 proteins. Our results further demonstrate that we have developed an effective biochemical approach to identify physiologically relevant human miRNA targets.
authors.affiliation: Laboratory of RNA Molecular Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, New York 10065, USA.
authors.forename: Markus
authors.initials: M
authors.lastname: Landthaler
authors.forename: Dimos
authors.initials: D
authors.lastname: Gaidatzis
authors.forename: Andrea
authors.initials: A
authors.lastname: Rothballer
authors.forename: Po Yu
authors.initials: PY
authors.lastname: Chen
authors.forename: Steven Joseph
authors.initials: SJ
authors.lastname: Soll
authors.forename: Lana
authors.initials: L
authors.lastname: Dinic
authors.forename: Tolulope
authors.initials: T
authors.lastname: Ojo
authors.forename: Markus
authors.initials: M
authors.lastname: Hafner
authors.forename: Mihaela
authors.initials: M
authors.lastname: Zavolan
authors.forename: Thomas
authors.initials: T
authors.lastname: Tuschl
mesh_terms: D002460:Cell Line; D039642:Eukaryotic Initiation Factors / Q000378:metabolism*; D006801:Humans; D047468:Immunoprecipitation; D035683:MicroRNAs / Q000378:metabolism; D020543:Proteome; D012333:RNA, Messenger / Q000378:metabolism*; D012261:Ribonucleoproteins / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism; D014162:Transfection
chemical_list: D039642:Eukaryotic Initiation Factors; C531907:MIRN122 microRNA, human; D035683:MicroRNAs; D020543:Proteome; D012333:RNA, Messenger; D012261:Ribonucleoproteins