Novel mono- and di-DNA-enzymes targeted to cleave TAT or TAT-REV RNA inhibit HIV-1 gene expression

Hoshang Unwalla, Akhil C. Banerjea

Research output: Contribution to journalArticlepeer-review

29 Scopus citations


The regulatory proteins TAT and REV play a very important role in the transcription and replication of HIV-1. In order to seHIV-01lectively down regulate the expression of these genes we synthesized several mono- and one di-DNA-enzyme against the TAT or TAT-REV RNA. Several mono-DNA-enzymes possessing the 10-23 catalytic motif were assembled that were targeted to the predicted loop region of TAT or TAT/REV RNA. The cleavage efficiency of each mono-DNA-enzyme was variable and independent of the size of the predicted loop structure of the target RNA. DNA-enzyme targeted against the largest loop region cleaved the substrate RNA poorly. Mono-DNA-enzyme-5944 that targets only the TAT region cleaved the substrate poorly but the DNA-enzyme-5970 that overlaps TAT and REV showed potent cleavage activity. The two DNA-enzymes, when placed in tandem, cleaved the target RNA at multiple sites that were specific for the two mono-DNA-enzymes. Only Dz-5970 retained the ability to cleave the target RNA specifically at simulated physiological conditions. They were able to inhibit HIV-1 specific genes efficiently when introduced into a mammalian cell. The extent of inhibition correlated with their cleavage efficiency obtained at standard conditions of cleavage. Although DNA-enzyme-5970 showed the highest reduction ( ∼ 90%), other DNA-enzymes (mono-DNA-enzyme-5944 and the di-DNA-enzyme) also showed reduction to an extent of 60 and 80% respectively. The inhibitory effect of the DNA-enzyme could be overcome by providing HIV-1 TAT to the cells.

Original languageEnglish (US)
Pages (from-to)127-139
Number of pages13
JournalAntiviral Research
Issue number2
StatePublished - 2001


  • HIV-1 TAT
  • REV and ENV
  • RNA cleaving DNA-enzyme

ASJC Scopus subject areas

  • Virology
  • Pharmacology


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