Sensitivity of Mitochondrial Transcription and Resistance of RNA Polymerase II Dependent Nuclear Transcription to Antiviral Ribonucleosides

作者：Jamie J. Arnold, Suresh D. Sharma, Joy Y. Feng, Adrian S. Ray, Eric D. Smidansky, Maria L. Kireeva, Aesop Cho, Jason K. Perry, Jennifer E. Vela, Yeojin Park, Yili Xu, Tian Yang, Darius Babusis, Ona Barauskus, Blake R. Peterson, Averell Gnatt, Mikhail Kashlev, Weidong Zhong, Craig E. Cameron · 发表于：PLoS Pathogens · 年份：2012 · DOI：10.1371/journal.ppat.1003030 · 被引用次数：140 · 研究领域：Viral Infections and Immunology Research、Biochemical and Molecular Research、RNA modifications and cancer

Ribonucleoside analogues have potential utility as anti-viral, -parasitic, -bacterial and -cancer agents. However, their clinical applications have been limited by off target effects. Development of antiviral ribonucleosides for treatment of hepatitis C virus (HCV) infection has been hampered by appearance of toxicity during clinical trials that evaded detection during preclinical studies. It is well established that the human mitochondrial DNA polymerase is an off target for deoxyribonucleoside reverse transcriptase inhibitors. Here we test the hypothesis that triphosphorylated metabolites of therapeutic ribonucleoside analogues are substrates for cellular RNA polymerases. We have used ribonucleoside analogues with activity against HCV as model compounds for therapeutic ribonucleosides. We have included ribonucleoside analogues containing 2'-C-methyl, 4'-methyl and 4'-azido substituents that are non-obligate chain terminators of the HCV RNA polymerase. We show that all of the anti-HCV ribonucleoside analogues are substrates for human mitochondrial RNA polymerase (POLRMT) and eukaryotic core RNA polymerase II (Pol II) in vitro. Unexpectedly, analogues containing 2'-C-methyl, 4'-methyl and 4'-azido substituents were inhibitors of POLRMT and Pol II. Importantly, the proofreading activity of TFIIS was capable of excising these analogues from Pol II transcripts. Evaluation of transcription in cells confirmed sensitivity of POLRMT to antiviral ribonucleosides, while Pol II remaine...