title: eIF1A augments Ago2-mediated Dicer-independent miRNA biogenesis and RNA interference.
abstract: MicroRNA (miRNA) biogenesis and miRNA-guided RNA interference (RNAi) are essential for gene expression in eukaryotes. Here we report that translation initiation factor eIF1A directly interacts with Ago2 and promotes Ago2 activities in RNAi and miR-451 biogenesis. Biochemical and NMR analyses demonstrate that eIF1A binds to the MID domain of Ago2 and this interaction does not impair translation initiation. Alanine mutation of the Ago2-facing Lys56 in eIF1A impairs RNAi activities in human cells and zebrafish. The eIF1A-Ago2 assembly facilitates Dicer-independent biogenesis of miR-451, which mediates erythrocyte maturation. Human eIF1A (heIF1A), but not heIF1A(K56A), rescues the erythrocyte maturation delay in eif1axb knockdown zebrafish. Consistently, miR-451 partly compensates erythrocyte maturation defects in zebrafish with eif1axb knockdown and eIF1A(K56A) expression, supporting a role of eIF1A in miRNA-451 biogenesis in this model. Our results suggest that eIF1A is a novel component of the Ago2-centred RNA-induced silencing complexes (RISCs) and augments Ago2-dependent RNAi and miRNA biogenesis.
authors.affiliation: Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Avenue, Boston, Massachusetts 02115, USA.
authors.forename: Tingfang
authors.initials: T
authors.lastname: Yi
authors.affiliation: Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Avenue, Boston, Massachusetts 02115, USA.
authors.forename: Haribabu
authors.initials: H
authors.lastname: Arthanari
authors.affiliation: Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Avenue, Boston, Massachusetts 02115, USA.|Department of Chemistry, Ben-Gurion University of the Negev, Be'er-Sheva 84105, Israel.
authors.forename: Barak
authors.initials: B
authors.lastname: Akabayov
authors.affiliation: Department of Pediatrics, Children's Hospital Boston, Boston, Massachusetts 02115, USA.
authors.forename: Huaidong
authors.initials: H
authors.lastname: Song
authors.affiliation: Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Avenue, Boston, Massachusetts 02115, USA.
authors.forename: Evangelos
authors.initials: E
authors.lastname: Papadopoulos
authors.affiliation: Department of Anatomy and Cell Biology, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242, USA.
authors.forename: Hank H
authors.initials: HH
authors.lastname: Qi
authors.affiliation: Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, Massachusetts 02115, USA.
authors.forename: Mark
authors.initials: M
authors.lastname: Jedrychowski
authors.affiliation: Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, Massachusetts 02115, USA.
authors.forename: Thomas
authors.initials: T
authors.lastname: Güttler
authors.affiliation: Department of Pediatrics, Children's Hospital Boston, Boston, Massachusetts 02115, USA.
authors.forename: Cuicui
authors.initials: C
authors.lastname: Guo
authors.affiliation: Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Avenue, Boston, Massachusetts 02115, USA.
authors.forename: Rafael E
authors.initials: RE
authors.lastname: Luna
authors.affiliation: Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, Massachusetts 02115, USA.
authors.forename: Steven P
authors.initials: SP
authors.lastname: Gygi
authors.affiliation: Department of Pediatrics, Children's Hospital Boston, Boston, Massachusetts 02115, USA.
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Huang
authors.affiliation: Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Avenue, Boston, Massachusetts 02115, USA.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Wagner
mesh_terms: D000818:Animals; D060565:Argonaute Proteins / Q000378:metabolism*; D015152:Blotting, Northern; D015153:Blotting, Western; D053487:DEAD-box RNA Helicases / Q000378:metabolism*; D015977:Eukaryotic Initiation Factor-1 / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation / Q000235:genetics*; D055785:Gene Knockdown Techniques; D057809:HEK293 Cells; D006801:Humans; D047468:Immunoprecipitation; D066298:In Vitro Techniques; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D035683:MicroRNAs / Q000096:biosynthesis*; D016297:Mutagenesis, Site-Directed; D034622:RNA Interference; D060888:Real-Time Polymerase Chain Reaction; D043244:Ribonuclease III / Q000378:metabolism*; D015027:Zebrafish
chemical_list: C466422:AGO2 protein, human; D060565:Argonaute Proteins; D015977:Eukaryotic Initiation Factor-1; C531201:MIRN451 microRNA, human; D035683:MicroRNAs; C026022:eukaryotic peptide initiation factor-1A; C408087:DICER1 protein, human; D043244:Ribonuclease III; D053487:DEAD-box RNA Helicases