Rift Valley fever virus Gn V5-epitope tagged virus enables identification of UBR4 as a Gn interacting protein that facilitates Rift Valley fever virus production

Virology. 2022 Feb;567:65-76. doi: 10.1016/j.virol.2021.12.010. Epub 2022 Jan 7.


Rift Valley fever virus (RVFV) is an arbovirus that was first reported in the Rift Valley of Kenya which causes significant disease in humans and livestock. RVFV is a tri-segmented, negative-sense RNA virus consisting of a L, M, and S segments with the M segment encoding the glycoproteins Gn and Gc. Host factors that interact with Gn are largely unknown. To this end, two viruses containing an epitope tag (V5) on the Gn protein in position 105 or 229 (V5Gn105 and V5Gn229) were generated using the RVFV MP-12 vaccine strain as a backbone. The V5-tag insertion minimally impacted Gn functionality as measured by replication kinetics, Gn localization, and antibody neutralization assays. A proteomics-based approach was used to identify novel Gn-binding host proteins, including the E3 ubiquitin-protein ligase, UBR4. Depletion of UBR4 resulted in a significant decrease in RVFV titers and a reduction in viral RNA production.

Keywords: Glycoproteins; Gn; Rift valley fever virus; UBR4.

Publication types

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

MeSH terms

  • Animals
  • Antibodies, Neutralizing / metabolism
  • Antibodies, Viral / metabolism
  • Calmodulin-Binding Proteins / genetics*
  • Calmodulin-Binding Proteins / metabolism
  • Cell Line
  • Cell Line, Tumor
  • Culex
  • Epitopes / chemistry
  • Epitopes / metabolism
  • Gene Expression Profiling
  • Gene Expression Regulation
  • HEK293 Cells
  • Hepatocytes / virology
  • Host-Pathogen Interactions / genetics*
  • Humans
  • Protein Binding
  • Rift Valley fever virus / genetics*
  • Rift Valley fever virus / metabolism
  • Signal Transduction
  • Ubiquitin-Protein Ligases / genetics*
  • Ubiquitin-Protein Ligases / metabolism
  • Viral Envelope Proteins / genetics*
  • Viral Envelope Proteins / metabolism
  • Virus Replication


  • Antibodies, Neutralizing
  • Antibodies, Viral
  • Calmodulin-Binding Proteins
  • Epitopes
  • Viral Envelope Proteins
  • UBR4 protein, human
  • Ubiquitin-Protein Ligases