title: Ligand-mediated transcription elongation control using triplex-based padlock oligonucleotides.
abstract: Triplex-forming oligonucleotides (TFOs) provide useful tools for the artificial regulation of gene expression at the transcriptional level. They can become topologically linked to their DNA target upon circularization, thereby forming very stable triple helical structures. These "padlock oligonucleotides" are able to interfere with transcription elongation when their target site is located in the transcribed region of a gene. In vitro transcription experiments showed that a bacterial RNA polymerase was stopped at the site of triple-helix formation, whereas expression of a reporter gene was inhibited in live cells. In both cases, the padlock oligonucleotide was more efficient at inhibiting transcription elongation than a linear TFO, and the inhibition was observed only in the presence of a triplex stabilizing agent. These results provide new insights into the ligand-modulated locking of padlock oligonucleotides around their DNA target.
authors.affiliation: Laboratoire de Biophysique, Muséum National d'Histoire Naturelle, INSERM U565, CNRS UMR5153, 43 rue Cuvier, 75231 Paris Cedex 05, France.
authors.forename: Mahajoub
authors.initials: M
authors.lastname: Bello-Roufaï
authors.forename: Thibaut
authors.initials: T
authors.lastname: Roulon
authors.forename: Christophe
authors.initials: C
authors.lastname: Escudé
mesh_terms: D001419:Bacteria / Q000201:enzymology / Q000235:genetics; D001483:Base Sequence; D004247:DNA / Q000737:chemistry* / Q000187:drug effects; D012321:DNA-Directed RNA Polymerases / Q000037:antagonists & inhibitors; D005786:Gene Expression Regulation / Q000187:drug effects; D006367:HeLa Cells / Q000187:drug effects; D006801:Humans; D008024:Ligands; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009841:Oligonucleotides / Q000737:chemistry* / Q000494:pharmacology*; D014158:Transcription, Genetic / Q000187:drug effects*
chemical_list: D008024:Ligands; D009841:Oligonucleotides; C051802:triplex DNA; D004247:DNA; D012321:DNA-Directed RNA Polymerases