Amantadine as a regulator of internal ribosome entry site

• 来源期刊: 中国药理学报（英文版）
• 关键词: amantadine Enterovirus 71 internal ribosome entry site riboswich
• 年，卷（期）: 2008,（11）
• 页码范围: 1327-1333
• 页数: 7页
• 语种: 英文
• DOI: 10.1111/j.1745-7254.2008.00876.x

摘要

Aim: Studies of eukaryotes have yielded 2 translation initiation mechanisms: a classical cap-dependent mechanism and a cap-independent mechanism proceeding through the internal ribosomal entry site (IRES). We hypothesized that it might be possible to identify compounds that may distinguish between cap-dependent translation and cap-independent IRES-mediated translation. Methods: To facilitate compound screening, we developed bicistronic reporter constructs containing a β-galactosidase gene (β-gal) and a secreted human placental alkaline phosphatase (SEAP) reporter gene. Following transcription, the β-gal gene is translated by a cap-dependent mechanism, while SEAP expression is controlled by the IRES derived from either enterovirus 71 (EV-71) or encephalomyocarditis virus (EMCV). This assay could potentially identify compounds that inhibit SEAP expression (cap-independent) without affecting β-gal activity (cap-dependent). Results: Using a bicistronic plasmid-based transient transfection assay in the COS-1 cells, we identified amantadine, a compound that inhibited the IRES of EV71- and EMCV-mediated cap-independent translation but did not interfere with cap-dependent translation when the dose of amantadine was lower than 0.25 rag/mE Conclusion: These results imply that amantadine may distinguish be-tween cap-dependent translation and cap-independent IRES-mediated translation and can be used to regulate gene expression at a translational level.