title: RNA helicase A modulates translation of HIV-1 and infectivity of progeny virions.
abstract: Retroviruses rely on host RNA-binding proteins to modulate various steps in their replication. Previously several animal retroviruses were determined to mediate Dhx9/RNA helicase A (RHA) interaction with a 5' terminal post-transcriptional control element (PCE) for efficient translation. Herein PCE reporter assays determined HTLV-1 and HIV-1 RU5 confer orientation-dependent PCE activity. The effect of Dhx9/RHA down-regulation and rescue with siRNA-resistant RHA on expression of HIV-1(NL4-3) provirus determined that RHA is necessary for efficient HIV-1 RNA translation and requires ATPase-dependent helicase function. Quantitative analysis determined HIV-1 RNA steady-state and cytoplasmic accumulation were not reduced; rather the translational activity of viral RNA was reduced. Western blotting determined that RHA-deficient virions assemble with Lys-tRNA synthetase, exhibit processed reverse transcriptase and contain similar level of viral RNA, but they are poorly infectious on primary lymphocytes and HeLa cells. The results demonstrate RHA is an important host factor within the virus-producer cell and within the viral particle. The identification of RHA-dependent PCE activity in cellular junD RNA and in six of seven genera of Retroviridae suggests conservation of this translational control mechanism among vertebrates, and convergent evolution of Retroviridae to utilize this host mechanism.
authors.affiliation: Department of Veterinary Biosciences, Center for Retrovirus Research and Center for RNA Biology, The Ohio State University, Columbus, OH 43210-1093, USA.
authors.forename: Cheryl
authors.initials: C
authors.lastname: Bolinger
authors.forename: Amit
authors.initials: A
authors.lastname: Sharma
authors.forename: Deepali
authors.initials: D
authors.lastname: Singh
authors.forename: Lianbo
authors.initials: L
authors.lastname: Yu
authors.forename: Kathleen
authors.initials: K
authors.lastname: Boris-Lawrie
mesh_terms: D001483:Base Sequence; D002460:Cell Line; D053487:DEAD-box RNA Helicases / Q000502:physiology*; D016325:HIV Long Terminal Repeat; D015497:HIV-1 / Q000235:genetics* / Q000502:physiology*; D015368:Human T-lymphotropic virus 1 / Q000235:genetics; D006801:Humans; D008250:Lysine-tRNA Ligase / Q000502:physiology; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000502:physiology*; D014176:Protein Biosynthesis; D012367:RNA, Viral / Q000378:metabolism; D020079:Terminal Repeat Sequences; D014771:Virion / Q000502:physiology*; D019065:Virus Assembly; D054301:gag Gene Products, Human Immunodeficiency Virus / Q000096:biosynthesis / Q000235:genetics
chemical_list: D009363:Neoplasm Proteins; D012367:RNA, Viral; D054301:gag Gene Products, Human Immunodeficiency Virus; C098487:DHX9 protein, human; D053487:DEAD-box RNA Helicases; D008250:Lysine-tRNA Ligase