Autophagy protein ATG5 interacts transiently with the hepatitis C virus RNA polymerase (NS5B) early during infection

• Published in: Virology (New York, N.Y.) Vol. 405; no. 1; pp. 1 - 7
• Main Authors: Guévin, Carl, Manna, David, Bélanger, Claudia, Konan, Kouacou V, Mak, Paul, Labonté, Patrick
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 15-09-2010; Elsevier
• Subjects: ATG5; Autophagy; Autophagy-Related Protein 5; Cell Line; Equine arteritis virus; Gene Expression Regulation; Gene Expression Regulation - physiology; Gene Silencing; HCV; Hepacivirus; Hepacivirus - enzymology; Hepatitis C virus; Human health and pathology; Humans; Infectious Disease; Infectious diseases; Life Sciences; Microtubule-Associated Proteins; Microtubule-Associated Proteins - chemistry; Microtubule-Associated Proteins - genetics; Microtubule-Associated Proteins - metabolism; NS5B; Poliovirus; Protein Binding; Protein Structure, Tertiary; Rapid Communication; RdRp; siRNA; Two-Hybrid System Techniques; Viral Nonstructural Proteins; Viral Nonstructural Proteins - genetics; Viral Nonstructural Proteins - metabolism; Virus Replication; double membrane vesicle; RdRp; NS5B; hepatitis C virus; HCV; siRNA; DMV; autophagy-related gene 5; Autophagy; ATG5
• ISSN: 0042-6822; 1096-0341
• DOI: 10.1016/j.virol.2010.05.032

Abstract Autophagy is an important cellular process by which ATG5 initiates the formation of double membrane vesicles (DMVs). Upon infection, DMVs have been shown to harbor the replicase complex of positive-strand RNA viruses such as MHV, poliovirus, and equine arteritis virus. Recently, it has been shown that autophagy proteins are proviral factors that favor initiation of hepatitis C virus (HCV) infection. Here, we identified ATG5 as an interacting protein for the HCV NS5B. ATG5/NS5B interaction was confirmed by co-IP and metabolic labeling studies. Furthermore, ATG5 protein colocalizes with NS4B, a constituent of the membranous web. Importantly, immunofluorescence staining demonstrated a strong colocalization of ATG5 and NS5B within perinuclear regions of infected cells at 2 days postinfection. However, colocalization was completely lacking at 5 DPI, suggesting that HCV utilizes ATG5 as a proviral factor during the onset of viral infection. Finally, inhibition of autophagy through ATG5 silencing blocks HCV replication.