MARCH8 Ubiquitinates the Hepatitis C Virus Nonstructural 2 Protein and Mediates Viral Envelopment

Cell Rep. 2019 Feb 12;26(7):1800-1814.e5. doi: 10.1016/j.celrep.2019.01.075.

Abstract

The mechanisms that regulate envelopment of HCV and other viruses that bud intracellularly and/or lack late-domain motifs are largely unknown. We reported that K63 polyubiquitination of the HCV nonstructural (NS) 2 protein mediates HRS (ESCRT-0 component) binding and envelopment. Nevertheless, the ubiquitin signaling that governs NS2 ubiquitination remained unknown. Here, we map the NS2 interactome with the ubiquitin proteasome system (UPS) via mammalian cell-based screens. NS2 interacts with E3 ligases, deubiquitinases, and ligase regulators, some of which are candidate proviral or antiviral factors. MARCH8, a RING-finger E3 ligase, catalyzes K63-linked NS2 polyubiquitination in vitro and in HCV-infected cells. MARCH8 is required for infection with HCV, dengue, and Zika viruses and specifically mediates HCV envelopment. Our data reveal regulation of HCV envelopment via ubiquitin signaling and both a viral protein substrate and a ubiquitin K63-linkage of the understudied MARCH8, with potential implications for cell biology, virology, and host-targeted antiviral design.

Keywords: ESCRT; HCV; MARCH8; assembly; envelopment; hepatitis C virus; intracellular membrane trafficking; proteomics; ubiquitination; virus-host interactions.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line, Tumor
  • Endoplasmic Reticulum / metabolism
  • HEK293 Cells
  • Hepacivirus / metabolism*
  • Hepacivirus / pathogenicity
  • Hepatitis C / genetics
  • Hepatitis C / metabolism
  • Hepatitis C / virology*
  • Humans
  • Signal Transduction
  • Ubiquitin / metabolism
  • Ubiquitin-Protein Ligases / genetics
  • Ubiquitin-Protein Ligases / metabolism*
  • Ubiquitination
  • Viral Nonstructural Proteins / metabolism*

Substances

  • NS2 protein, Hepatitis C virus
  • Ubiquitin
  • Viral Nonstructural Proteins
  • MARCHF8 protein, human
  • Ubiquitin-Protein Ligases