title: HIV-1 and Human PEG10 Frameshift Elements Are Functionally Distinct and Distinguished by Novel Small Molecule Modulators.
abstract: Frameshifting during translation of viral or in rare cases cellular mRNA results in the synthesis of proteins from two overlapping reading frames within the same mRNA. In HIV-1 the protease, reverse transcriptase, and integrase enzymes are in a second reading frame relative to the structural group-specific antigen (gag), and their synthesis is dependent upon frameshifting. This ensures that a strictly regulated ratio of structural proteins and enzymes, which is critical for HIV-1 replication and viral infectivity, is maintained during protein synthesis. The frameshift element in HIV-1 RNA is an attractive target for the development of a new class of anti HIV-1 drugs. However, a number of examples are now emerging of human genes using -1 frameshifting, such as PEG10 and CCR5. In this study we have compared the HIV-1 and PEG10 frameshift elements and shown they have distinct functional characteristics. Frameshifting occurs at several points within each element. Moreover, frameshift modulators that were isolated by high-throughput screening of a library of 114,000 lead-like compounds behaved differently with the PEG10 frameshift element. The most effective compounds affecting the HIV-1 element enhanced frameshifting by 2.5-fold at 10 μM in two different frameshift reporter assay systems. HIV-1 protease:gag protein ratio was affected by a similar amount in a specific assay of virally-infected cultured cell, but the modulation of frameshifting of the first-iteration compounds was not sufficient to show significant effects on viral infectivity. Importantly, two compounds did not affect frameshifting with the human PEG10 element, while one modestly inhibited rather than enhanced frameshifting at the human element. These studies indicate that frameshift elements have unique characteristics that may allow targeting of HIV-1 and of other viruses specifically for development of antiviral therapeutic molecules without effect on human genes like PEG10 that use the same generic mechanism.
authors.affiliation: Department of Biochemistry, University of Otago, Dunedin, New Zealand; The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia.
authors.forename: Tony S
authors.initials: TS
authors.lastname: Cardno
authors.affiliation: Department of Biochemistry, University of Otago, Dunedin, New Zealand.
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Shimaki
authors.affiliation: The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia; Department of Medical Biology, University of Melbourne, Parkville, Australia.
authors.forename: Brad E
authors.initials: BE
authors.lastname: Sleebs
authors.affiliation: The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia; Department of Medical Biology, University of Melbourne, Parkville, Australia.
authors.forename: Kurt
authors.initials: K
authors.lastname: Lackovic
authors.affiliation: Department of Medical Biology, University of Melbourne, Parkville, Australia.
authors.forename: John P
authors.initials: JP
authors.lastname: Parisot
authors.affiliation: The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia; Department of Medical Biology, University of Melbourne, Parkville, Australia.
authors.forename: Rebecca M
authors.initials: RM
authors.lastname: Moss
authors.affiliation: Department of Biochemistry, University of Otago, Dunedin, New Zealand.
authors.forename: Caillan
authors.initials: C
authors.lastname: Crowe-McAuliffe
authors.affiliation: Department of Biochemistry, University of Otago, Dunedin, New Zealand.
authors.forename: Suneeth F
authors.initials: SF
authors.lastname: Mathew
authors.affiliation: Department of Biochemistry, University of Otago, Dunedin, New Zealand.
authors.forename: Christina D
authors.initials: CD
authors.lastname: Edgar
authors.affiliation: Department of Biochemistry, University of Otago, Dunedin, New Zealand; Centre for Protein Research, University of Otago, Dunedin, New Zealand.
authors.forename: Torsten
authors.initials: T
authors.lastname: Kleffmann
authors.affiliation: Department of Biochemistry, University of Otago, Dunedin, New Zealand.
authors.forename: Warren P
authors.initials: WP
authors.lastname: Tate
mesh_terms: D051017:Apoptosis Regulatory Proteins; D001483:Base Sequence; D002851:Chromatography, High Pressure Liquid; D004268:DNA-Binding Proteins; D016368:Frameshift Mutation; D017930:Genes, Reporter; D057809:HEK293 Cells; D015497:HIV-1 / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D013058:Mass Spectrometry; D009690:Nucleic Acid Conformation; D014176:Protein Biosynthesis; D011506:Proteins / Q000378:metabolism*; D012367:RNA, Viral / Q000378:metabolism*; D016601:RNA-Binding Proteins; D054852:Small Molecule Libraries / Q000737:chemistry*
chemical_list: D051017:Apoptosis Regulatory Proteins; D004268:DNA-Binding Proteins; C432965:PEG10 protein, human; D011506:Proteins; D012367:RNA, Viral; D016601:RNA-Binding Proteins; D054852:Small Molecule Libraries