AMFR-mediated Flavivirus NS2A ubiquitination subverts ER-phagy to augment viral pathogenicity

Nat Commun. 2024 Nov 6;15(1):9578. doi: 10.1038/s41467-024-54010-w.

Abstract

Flaviviruses strategically utilize the endoplasmic reticulum (ER) in their replication cycles. However, the role of ER autophagy (ER-phagy) in viral replication process remains poorly understood. Here, we reveal that prolonged Zika virus (ZIKV) infection results from the degradation of ER-phagy receptor FAM134B, facilitated by viral NS2A protein. Mechanistically, ER-localized NS2A undergoes K48-linked polyubiquitination at lysine (K) 56 by E3 ligase AMFR. Ubiquitinated NS2A binds to FAM134B and AMFR orchestrates the degradation of NS2A-FAM134B complexes. AMFR-catalyzed NS2A ubiquitination not only targets FAM134B degradation but also hinders the FAM134B-AMFR axis. Notably, a recombinant ZIKV mutant (ZIKV-NS2AK56R), lacking ubiquitination and ER-phagy inhibition, exhibits attenuation in ZIKV-induced microcephalic phenotypes in human brain organoids and replicates less efficiently, resulting in weakened pathogenesis in mouse models. In this work, our mechanistic insights propose that flaviviruses manipulate ER-phagy to modulate ER turnover, driving viral infection. Furthermore, AMFR-mediated flavivirus NS2A ubiquitination emerges as a potential determinant of viral pathogenecity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Autophagy*
  • Cell Line
  • Chlorocebus aethiops
  • Disease Models, Animal
  • Endoplasmic Reticulum* / metabolism
  • Endoplasmic Reticulum* / pathology
  • Endoplasmic Reticulum* / virology
  • Female
  • Humans
  • Intracellular Signaling Peptides and Proteins
  • Male
  • Membrane Proteins* / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Mutation
  • Receptors, Autocrine Motility Factor* / metabolism
  • Ubiquitination / genetics
  • Viral Nonstructural Proteins* / genetics
  • Viral Nonstructural Proteins* / metabolism
  • Virus Replication
  • Zika Virus Infection* / pathology
  • Zika Virus Infection* / virology
  • Zika Virus* / genetics
  • Zika Virus* / pathogenicity

Substances

  • Membrane Proteins
  • Receptors, Autocrine Motility Factor
  • Viral Nonstructural Proteins
  • AMFR protein, human
  • Amfr protein, mouse
  • Fam134b protein, mouse
  • POLY protein, Zika virus
  • RETREG1 protein, human
  • Intracellular Signaling Peptides and Proteins