Attenuated West Nile virus mutant NS1130-132QQA/175A/207A exhibits virus-induced ultrastructural changes and accumulation of protein in the endoplasmic reticulum

Melissa C Whiteman; Vsevolod Popov; Michael B Sherman; Julie Wen; Alan D T Barrett

doi:10.1128/JVI.02215-14

Attenuated West Nile virus mutant NS1130-132QQA/175A/207A exhibits virus-induced ultrastructural changes and accumulation of protein in the endoplasmic reticulum

J Virol. 2015 Jan 15;89(2):1474-8. doi: 10.1128/JVI.02215-14. Epub 2014 Nov 12.

Authors

Melissa C Whiteman¹, Vsevolod Popov², Michael B Sherman³, Julie Wen⁴, Alan D T Barrett⁵

Affiliations

¹ Sealy Center for Vaccine Development, University of Texas Medical Branch, Galveston, Texas, USA.
² Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA Center for Biodefense and Emerging Infectious Diseases, University of Texas Medical Branch, Galveston, Texas, USA.
³ Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, Texas, USA Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, Texas, USA.
⁴ Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA.
⁵ Sealy Center for Vaccine Development, University of Texas Medical Branch, Galveston, Texas, USA Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA Center for Biodefense and Emerging Infectious Diseases, University of Texas Medical Branch, Galveston, Texas, USA Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, USA [email protected].

Abstract

We have previously shown that ablation of the three N-linked glycosylation sites in the West Nile virus NS1 protein completely attenuates mouse neuroinvasiveness (≥1,000,000 PFU). Here, we compared the replication of the NS1130-132QQA/175A/207A mutant to that of the parental NY99 strain in monkey kidney Vero cells. The results suggest that the mechanism of attenuation is a lack of NS1 glycosylation, which blocks efficient replication, maturation, and NS1 secretion from the endoplasmic reticulum and results in changes to the virus-induced ultrastructure.

Publication types

Research Support, N.I.H., Extramural

MeSH terms

Amino Acid Substitution*
Animals
Chlorocebus aethiops
Electron Microscope Tomography
Endoplasmic Reticulum / chemistry*
Glycosylation
Mice
Microscopy, Electron, Transmission
Microscopy, Fluorescence
Mutant Proteins / genetics
Mutant Proteins / metabolism
Organelles / ultrastructure*
Vero Cells
Viral Nonstructural Proteins / genetics
Viral Nonstructural Proteins / metabolism*
Virus Replication*
West Nile virus / genetics
West Nile virus / physiology*

Substances

Mutant Proteins
Viral Nonstructural Proteins
nonstructural protein 1, West Nile virus

Grants and funding

T32 AI007536/AI/NIAID NIH HHS/United States