title: Inhibition of Tat-mediated transactivation of HIV-1 LTR transcription by polyamide nucleic acid targeted to TAR hairpin element.
abstract: Tat, an essential human immunodeficiency virus type 1 protein interacts with the transactivation response element (TAR) and stimulates transcription from the viral long-terminal repeat (LTR). Blockage of Tat-TAR interaction halts viral transcription and hence replication. We have found that polyamide nucleic acid (PNA), targeted to the TAR sequences of viral RNA genome is able to prevent Tat-TAR interaction by efficient sequestration of the TAR. Anti-TAR PNA competes for TAR and prevents Tat-mediated stimulation of HIV-1 LTR transcription in vitro but has no influence on the basal level of transcription in the absence of Tat. Using a reporter gene construct pHIV LTR-CAT and pCMV-Tat in cell culture, we have further shown that anti-TAR PNA is able to block Tat-mediated transactivation of HIV-1 LTR transcription in vivo as judged by the extent of LTR driven CAT gene expression in the absence and presence of anti-TAR PNA. Supplementation of 100 nM of anti-TAR PNA into the culture medium further enhances the suppression of transactivation. Nonspecific scrambled PNA had no influence on Tat-TAR interaction and LTR-driven CAT gene expression in cell culture. These results suggest that PNA targeted to the TAR sequence of the viral genome may be a potential inhibitor of HIV-1 gene expression.
authors.affiliation: Department of Biochemistry and Molecular Biology, UMD-New Jersey Medical School, 185 South Orange Avenue, Newark, New Jersey 07103, USA.
authors.forename: T
authors.initials: T
authors.lastname: Mayhood
authors.forename: N
authors.initials: N
authors.lastname: Kaushik
authors.forename: P K
authors.initials: PK
authors.lastname: Pandey
authors.forename: F
authors.initials: F
authors.lastname: Kashanchi
authors.forename: L
authors.initials: L
authors.lastname: Deng
authors.forename: V N
authors.initials: VN
authors.lastname: Pandey
mesh_terms: D000998:Antiviral Agents / Q000737:chemistry* / Q000378:metabolism; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D002460:Cell Line; D015500:Chloramphenicol O-Acetyltransferase / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000235:genetics; D015696:Gene Products, tat / Q000037:antagonists & inhibitors* / Q000737:chemistry* / Q000235:genetics; D016325:HIV Long Terminal Repeat; D015497:HIV-1 / Q000235:genetics; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D020135:Peptide Nucleic Acids / Q000737:chemistry* / Q000378:metabolism; D012367:RNA, Viral / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D020218:Response Elements / Q000235:genetics*; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014162:Transfection; D054322:tat Gene Products, Human Immunodeficiency Virus
chemical_list: D000998:Antiviral Agents; D015696:Gene Products, tat; D020135:Peptide Nucleic Acids; D012367:RNA, Viral; D054322:tat Gene Products, Human Immunodeficiency Virus; D015500:Chloramphenicol O-Acetyltransferase