title: Transcription inhibition using modified pentanucleotides.
abstract: Inhibition of gene expression was recently achieved by targeting the transcriptionally competent open complex using relatively short, pentameric modified oligonucleotides at approximately 60 microM. Corroborative affinity cleavage experiments using the copper complex of a phenanthroline conjugate provided the impetus to synthesize additional analogues containing substituents at the 2'-position of uridine in a derivative of 5'-GUGGA (-4 to +1), with the purpose of inhibiting transcription at lower concentrations. Conjugates of 5'-GUGGA modified at the 2'-position of uridine were convergently synthesized using a recently reported method. Seven analogues based upon the 5'-GUGGA scaffold were tested for their ability to inhibit transcription of the lac UV-5 operon. The conjugate containing a tethered pyrene showed 70% inhibition at 20 microM, and modest inhibition at as low as 5 microM. This is a significant improvement over previously tested pentanucleotides and provides direction for the preparation of a next generation of inhibitors.
authors.affiliation: Department of Chemistry, Colorado State University, Fort Collins, CO 80523, USA.
authors.forename: Jae-Taeg
authors.initials: JT
authors.lastname: Hwang
authors.forename: Francis E
authors.initials: FE
authors.lastname: Baltasar
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Cole
authors.forename: David S
authors.initials: DS
authors.lastname: Sigman
authors.forename: Chi-hong B
authors.initials: CH
authors.lastname: Chen
authors.forename: Marc M
authors.initials: MM
authors.lastname: Greenberg
mesh_terms: D002851:Chromatography, High Pressure Liquid; D003300:Copper / Q000737:chemistry; D012321:DNA-Directed RNA Polymerases / Q000235:genetics / Q000378:metabolism; D024202:Electrophoretic Mobility Shift Assay; D015870:Gene Expression / Q000187:drug effects; D005821:Genetic Techniques; D007763:Lac Operon; D015394:Molecular Structure; D009843:Oligoribonucleotides / Q000737:chemistry* / Q000235:genetics / Q000494:pharmacology; D010618:Phenanthrolines / Q000737:chemistry; D013698:Templates, Genetic; D014158:Transcription, Genetic / Q000187:drug effects*; D014529:Uridine / Q000031:analogs & derivatives / Q000378:metabolism
chemical_list: D009843:Oligoribonucleotides; D010618:Phenanthrolines; D003300:Copper; D012321:DNA-Directed RNA Polymerases; D014529:Uridine