title: The role of A-kinase anchoring protein 95-like protein in annealing of tRNALys3 to HIV-1 RNA.
abstract: BACKGROUND
  RNA helicase A (RHA), a DExH box protein, promotes annealing of tRNALys3, a primer for reverse transcription, to HIV-1 RNA and assembles into virus particles. A-kinase anchoring protein 95-like protein (HAP95) is a binding partner of RHA. The role of HAP95 in the annealing of tRNALys3 was examined in this study.
  
  
  RESULTS
  HAP95 associates with the reverse transcriptase region of Pol protein of HIV-1. Decreasing endogenous HAP95 in HIV-1-producing 293T cells by siRNA reduces the amount of tRNALys3 annealed on viral RNA. This defect was further deteriorated by knockdown of RHA in the same cells, suggesting a cooperative effect between these two proteins. Biochemical assay in vitro using purified GST-tagged HAP95 shows that HAP95 may inhibit the activity of RHA.
  
  
  CONCLUSIONS
  The results support a hypothesis that HAP95 may transiently block RHA's activity to protect the annealed tRNALys3 on viral RNA in the cells from removing by RHA during the packaging of RHA into virus particles, thus facilitating the annealing of tRNALys3 to HIV-1 RNA.
authors.affiliation: Lady Davis Institute for Medical Research and McGill AIDS Centre, Jewish General Hospital, Montreal, QC, Canada. xingli107@gmail.com.
authors.forename: Li
authors.initials: L
authors.lastname: Xing
authors.forename: Xia
authors.initials: X
authors.lastname: Zhao
authors.forename: Fei
authors.initials: F
authors.lastname: Guo
authors.forename: Lawrence
authors.initials: L
authors.lastname: Kleiman
mesh_terms: D002478:Cells, Cultured; D053487:DEAD-box RNA Helicases / Q000037:antagonists & inhibitors / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000502:physiology*; D015497:HIV-1 / Q000235:genetics* / Q000502:physiology; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000502:physiology*; D009363:Neoplasm Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D009687:Nuclear Proteins / Q000502:physiology*; D012357:RNA, Transfer, Lys / Q000737:chemistry*; D012367:RNA, Viral / Q000737:chemistry*; D014771:Virion / Q000502:physiology
chemical_list: C490117:AKAP8L protein, human; D004268:DNA-Binding Proteins; D047908:Intracellular Signaling Peptides and Proteins; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D012357:RNA, Transfer, Lys; D012367:RNA, Viral; C098487:DHX9 protein, human; D053487:DEAD-box RNA Helicases