N-glycosylation in the Pre-Membrane Protein Is Essential for the Zika Virus Life Cycle.

Yong-Dae Gwon,Eva Zusinaite,Anna K Överby,Magnus Evander,Andres Merits

doi:10.3390/v12090925

Abstract

Asparagine (N)-linked protein glycosylation plays an important role in protein synthesis and modification. Two Zika virus (ZIKV) structural proteins, the pre-membrane (prM) and envelope (E) protein are N-glycosylated. The prM protein of all ZIKV strains contains a single N-linked glycosylation site, while not all strains contain an N-linked site in the E protein. Our aim was to examine the impact of prM and E N-linked glycosylation on ZIKV infectivity and cell trafficking. Using a ZIKV infectious clone, we found that when the N-glycan sites were removed, the prM- and the prM/E-double mutants did not produce an infectious virus in the supernatant. Further, by using ZIKV prME constructs, we found that N-glycosylation was necessary for effective secretion of ZIKV virions. The absence of the N-glycan on prM or E caused protein aggregation in the rough endoplasmatic reticulum (ER) compartment. The aggregation was more pronounced for the prM-mutation, and the mutant virus lost the ER-Golgi intermediate compartment (ERGIC) localization. In addition, lack of the N-glycan on prM induced nuclear translocation of CCAAT-enhancer-binding protein homologous protein (CHOP), an ER stress marker. To conclude, we show that the prM N-glycan is essential for the ZIKV infectious cycle, and plays an important role in viral protein trafficking, protein folding, and virion assembly.

Highlights

Millions of people suffer from the emergence or re-emergence of flaviviruses [1].Zika virus (ZIKV) is an emerging flavivirus transmitted primarily byAedes mosquitoes [2]
We concluded that the lack of prM N-glycosylation in ZIKV negatively affected the virus spread from the host cell, which suggested a lack of progeny virus production or/and inability of progeny virions to infect naïve cells
ZIKV translates a single polyprotein from the genome and cleaves the polyprotein to several viral proteins [37]

Summary

Introduction

Millions of people suffer from the emergence or re-emergence of flaviviruses [1].Zika virus (ZIKV) is an emerging flavivirus (from the family of Flaviviridae) transmitted primarily byAedes mosquitoes [2]. Millions of people suffer from the emergence or re-emergence of flaviviruses [1]. Zika virus (ZIKV) is an emerging flavivirus (from the family of Flaviviridae) transmitted primarily by. ZIKV causes no symptoms or a dengue-like illness, with rashes, conjunctivitis, and other mild clinical manifestations [3,4]. Polynesia and the Americas showed that the virus was associated with clinical manifestations such as microcephaly and Guillain-Barré syndrome [5]. The structural proteins play important roles in the virus life cycle, attachment, entry into host cells, virion formation, maturation, and release of the matured virion [7]

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