title: RNA structure modulates splicing efficiency at the human immunodeficiency virus type 1 major splice donor.
abstract: The untranslated leader of the human immunodeficiency virus type 1 (HIV-1) RNA genome encodes essential sequence and structural motifs that control various replication steps. The 5' splice site or splice donor (SD) is embedded in a semistable hairpin, but the function of this structure is unknown. We stabilized this SD hairpin by creating an additional base pair and demonstrated a severe HIV-1 replication defect. A splicing defect was apparent in RNA analyses of virus-infected cells and cells transfected with appropriate reporter constructs. We selected multiple virus revertants in search for interesting second-site escape pathways. Most revertants acquired an additional mutation that modulated the stability of the mutant SD hairpin. One revertant acquired a single nucleotide change in the upstream DIS hairpin. We demonstrate that a novel SD site is created by this upstream mutation, which obviously reduces the number of leader nucleotides that are included in spliced HIV-1 transcripts. These results suggest a novel role of RNA structure in the regulation of HIV-1 splicing.
authors.affiliation: Laboratory of Experimental Virology, Department of Medical Microbiology, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands.
authors.forename: Truus E M
authors.initials: TE
authors.lastname: Abbink
authors.forename: Ben
authors.initials: B
authors.lastname: Berkhout
mesh_terms: D001483:Base Sequence; D045744:Cell Line, Tumor; D004797:Enzyme-Linked Immunosorbent Assay; D017930:Genes, Reporter; D015497:HIV-1 / Q000235:genetics* / Q000502:physiology; D006801:Humans; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D012326:RNA Splicing; D012367:RNA, Viral / Q000737:chemistry*; D014779:Virus Replication
chemical_list: D012367:RNA, Viral