Characterization of a multipurpose NS3 surface patch coordinating HCV replicase assembly and virion morphogenesis

PLoS Pathog. 2022 Oct 10;18(10):e1010895. doi: 10.1371/journal.ppat.1010895. eCollection 2022 Oct.

Abstract

The hepatitis C virus (HCV) life cycle is highly regulated and characterized by a step-wise succession of interactions between viral and host cell proteins resulting in the assembly of macromolecular complexes, which catalyse genome replication and/or virus production. Non-structural (NS) protein 3, comprising a protease and a helicase domain, is involved in orchestrating these processes by undergoing protein interactions in a temporal fashion. Recently, we identified a multifunctional NS3 protease surface patch promoting pivotal protein-protein interactions required for early steps of the HCV life cycle, including NS3-mediated NS2 protease activation and interactions required for replicase assembly. In this work, we extend this knowledge by identifying further NS3 surface determinants important for NS5A hyperphosphorylation, replicase assembly or virion morphogenesis, which map to protease and helicase domain and form a contiguous NS3 surface area. Functional interrogation led to the identification of phylogenetically conserved amino acid positions exerting a critical function in virion production without affecting RNA replication. These findings illustrate that NS3 uses a multipurpose protein surface to orchestrate the step-wise assembly of functionally distinct multiprotein complexes. Taken together, our data provide a basis to dissect the temporal formation of viral multiprotein complexes required for the individual steps of the HCV life cycle.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line
  • Hepacivirus* / physiology
  • Hepatitis C* / metabolism
  • Humans
  • Morphogenesis
  • Peptide Hydrolases / metabolism
  • Viral Nonstructural Proteins / metabolism
  • Virion / metabolism
  • Virus Assembly / genetics
  • Virus Replication / physiology

Substances

  • Viral Nonstructural Proteins
  • Peptide Hydrolases

Grants and funding

N.T. was funded by the Deutsche Forschungsgemeinschaft (DFG), project TA 218/3-1. R.B. is supported by the Deutsche Forschungsgemeinschaft (DFG), project number 240245660 – SFB 1129, project number 112927078 - TRR 83 and project number 272983813 – TRR 179. URL: http://www.dfg.de. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.