Loop-loop interaction of HIV-1 TAR RNA with N3'-->P5' deoxyphosphoramidate aptamers inhibits in vitro Tat-mediated transcription.
A hairpin RNA aptamer has been identified by in vitro selection against the transactivation-responsive element (TAR) of HIV-1. A nuclease-resistant N3' --> P5' phosphoramidate isosequential analog of this aptamer also folds as a hairpin and forms with TAR a loop-loop "kissing" complex with a binding constant in the low nanomolar range as demonstrated by electrophoretic mobility-shift assays and surface plasmon resonance experiments. The key structural determinants, which contribute to the stability of the RNA aptamer-TAR complex, loop complementarity and the GA residues closing the aptamer loop, remain crucial for the N3' --> P5' aptamer-TAR complex. Moreover, the N3' --> P5' phosphoramidate aptamer specifically interferes with the binding of a peptide derived from the transactivator protein (Tat) peptide to TAR and selectively inhibits the Tat-mediated transcription in an in vitro assay, which marks this nuclease-resistant aptamer as a relevant candidate for experiments in cells.
Darfeuille
Fabien
F
Institut National de la Santé et de la Recherche Médicale U386, Université Victor Segalen, 33076 Bordeaux Cédex, France.
Arzumanov
Andrey
A
Gryaznov
Sergei
S
Gait
Michael J
MJ
Di Primo
Carmelo
C
Toulmé
Jean-Jacques
JJ
D000577:Amides / Q000494:pharmacology*; D001483:Base Sequence; D015696:Gene Products, tat / Q000037:antagonists & inhibitors* / Q000378:metabolism; D016325:HIV Long Terminal Repeat / Q000235:genetics*; D015497:HIV-1 / Q000235:genetics*; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010756:Phosphoric Acids / Q000494:pharmacology*; D020349:Surface Plasmon Resonance; D014158:Transcription, Genetic / Q000187:drug effects*; D054322:tat Gene Products, Human Immunodeficiency Virus
D000577:Amides; D015696:Gene Products, tat; D010756:Phosphoric Acids; D054322:tat Gene Products, Human Immunodeficiency Virus; C011067:phosphoramidic acid