HEPATITIS-C VIRUS NONSTRUCTURAL PROTEIN 5A CONTAINS POTENTIAL TRANSCRIPTIONAL ACTIVATOR DOMAINS

Hepatitis C virus (HCV), a major etiologic agent of transfusion associ ated hepatitis, is a positive, single-stranded RNA virus and is also k nown to be implicated in liver cirrhosis and hepatocellular carcinoma. Nonstructural protein 5A (NS5A) of HCV contains acidic and proline-ri ch amino acids in its carboxy-terminal half. These structural features resemble eukaryotic transcription activators. In this report, we show that NS5A functions as a potent transcriptional activator when fused to the yeast (Saccharomyces cerevisiae) GAL4 DNA-binding domain (1-147 ). The potential transcriptional activator maps to the C-terminal half of NS5A in the yeast cell. Therefore, our data provides the first evi dence that NS5A may modulate host cell function at the transcriptional level.