title: Atomistic mechanism of microRNA translation upregulation via molecular dynamics simulations.
abstract: MicroRNAs are endogenous 23-25 nt RNAs that play important gene-regulatory roles in animals and plants. Recently, miR369-3 was found to upregulate translation of TNFα mRNA in quiescent (G0) mammalian cell lines. Knock down and immunofluorescence experiments suggest that microRNA-protein complexes (with FXR1 and AGO2) are necessary for the translation upregulation. However the molecular mechanism of microRNA translation activation is poorly understood. In this study we constructed the microRNA-mRNA-AGO2-FXR1 quadruple complex by bioinformatics and molecular modeling, followed with all atom molecular dynamics simulations in explicit solvent to investigate the interaction mechanisms for the complex. A combined analysis of experimental and computational data suggests that AGO2-FXR1 complex relocalize microRNA:mRNA duplex to polysomes in G0. The two strands of dsRNA are then separated upon binding of AGO2 and FXR1. Finally, polysomes may improve the translation efficiency of mRNA. The mutation research confirms the stability of microRNA-mRNA-FXR1 and illustrates importance of key residue of Ile304. This possible mechanism can shed more light on the microRNA-dependent upregulation of translation.
authors.affiliation: State Key Laboratory of Microbial metabolism, Department of Bioinformatics and Biostatistics, College of Life Sciences and Biotechnology, Shanghai Jiaotong University, Shanghai, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Ye
authors.forename: Fang
authors.initials: F
authors.lastname: Qin
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
authors.forename: Ray
authors.initials: R
authors.lastname: Luo
authors.forename: Hai-Feng
authors.initials: HF
authors.lastname: Chen
mesh_terms: D060565:Argonaute Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism; D035683:MicroRNAs / Q000737:chemistry / Q000378:metabolism*; D056004:Molecular Dynamics Simulation; D009690:Nucleic Acid Conformation; D017354:Point Mutation; D014176:Protein Biosynthesis; D017434:Protein Structure, Tertiary; D020871:RNA Stability; D012330:RNA, Double-Stranded / Q000737:chemistry / Q000378:metabolism; D012997:Solvents / Q000737:chemistry; D013816:Thermodynamics; D015854:Up-Regulation
chemical_list: D060565:Argonaute Proteins; D035683:MicroRNAs; D012330:RNA, Double-Stranded; D012997:Solvents