Characterization of host proteins interacting with the lymphocytic choriomeningitis virus L protein

PLoS Pathog. 2017 Dec 20;13(12):e1006758. doi: 10.1371/journal.ppat.1006758. eCollection 2017 Dec.

Abstract

RNA-dependent RNA polymerases (RdRps) play a key role in the life cycle of RNA viruses and impact their immunobiology. The arenavirus lymphocytic choriomeningitis virus (LCMV) strain Clone 13 provides a benchmark model for studying chronic infection. A major genetic determinant for its ability to persist maps to a single amino acid exchange in the viral L protein, which exhibits RdRp activity, yet its functional consequences remain elusive. To unravel the L protein interactions with the host proteome, we engineered infectious L protein-tagged LCMV virions by reverse genetics. A subsequent mass-spectrometric analysis of L protein pulldowns from infected human cells revealed a comprehensive network of interacting host proteins. The obtained LCMV L protein interactome was bioinformatically integrated with known host protein interactors of RdRps from other RNA viruses, emphasizing interconnected modules of human proteins. Functional characterization of selected interactors highlighted proviral (DDX3X) as well as antiviral (NKRF, TRIM21) host factors. To corroborate these findings, we infected Trim21-/- mice with LCMV and found impaired virus control in chronic infection. These results provide insights into the complex interactions of the arenavirus LCMV and other viral RdRps with the host proteome and contribute to a better molecular understanding of how chronic viruses interact with their host.

Publication types

  • Validation Study

MeSH terms

  • Animals
  • CRISPR-Cas Systems
  • Computational Biology
  • Crosses, Genetic
  • DEAD-box RNA Helicases / chemistry
  • DEAD-box RNA Helicases / metabolism*
  • Female
  • HEK293 Cells
  • Humans
  • Immunoprecipitation
  • Lymphocytic Choriomeningitis / metabolism
  • Lymphocytic Choriomeningitis / veterinary
  • Lymphocytic choriomeningitis virus / enzymology*
  • Male
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Models, Molecular*
  • Protein Interaction Domains and Motifs
  • RNA Replicase / chemistry
  • RNA Replicase / genetics
  • RNA Replicase / metabolism*
  • Recombinant Fusion Proteins / chemistry
  • Recombinant Fusion Proteins / metabolism
  • Repressor Proteins / chemistry
  • Repressor Proteins / metabolism*
  • Ribonucleoproteins / chemistry
  • Ribonucleoproteins / genetics
  • Ribonucleoproteins / metabolism*
  • Specific Pathogen-Free Organisms
  • Viral Proteins / chemistry
  • Viral Proteins / genetics
  • Viral Proteins / metabolism*

Substances

  • NKRF protein, human
  • Recombinant Fusion Proteins
  • Repressor Proteins
  • Ribonucleoproteins
  • SS-A antigen
  • Viral Proteins
  • RNA Replicase
  • DDX3X protein, human
  • DEAD-box RNA Helicases