Self-association and subcellular localization of Puumala hantavirus envelope proteins

Sci Rep. 2019 Jan 24;9(1):707. doi: 10.1038/s41598-018-36879-y.

Abstract

Hantavirus assembly and budding are governed by the surface glycoproteins Gn and Gc. In this study, we investigated the glycoproteins of Puumala, the most abundant Hantavirus species in Europe, using fluorescently labeled wild-type constructs and cytoplasmic tail (CT) mutants. We analyzed their intracellular distribution, co-localization and oligomerization, applying comprehensive live, single-cell fluorescence techniques, including confocal microscopy, imaging flow cytometry, anisotropy imaging and Number&Brightness analysis. We demonstrate that Gc is significantly enriched in the Golgi apparatus in absence of other viral components, while Gn is mainly restricted to the endoplasmic reticulum (ER). Importantly, upon co-expression both glycoproteins were found in the Golgi apparatus. Furthermore, we show that an intact CT of Gc is necessary for efficient Golgi localization, while the CT of Gn influences protein stability. Finally, we found that Gn assembles into higher-order homo-oligomers, mainly dimers and tetramers, in the ER while Gc was present as mixture of monomers and dimers within the Golgi apparatus. Our findings suggest that PUUV Gc is the driving factor of the targeting of Gc and Gn to the Golgi region, while Gn possesses a significantly stronger self-association potential.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bacterial Proteins / metabolism
  • Cell Membrane / metabolism
  • Cell Membrane / virology
  • Chlorocebus aethiops
  • Endoplasmic Reticulum / metabolism
  • Endoplasmic Reticulum / virology
  • Glycoproteins / chemistry
  • Glycoproteins / metabolism*
  • Golgi Apparatus / metabolism
  • Golgi Apparatus / virology
  • HEK293 Cells
  • Hantavirus Infections / metabolism*
  • Hantavirus Infections / virology
  • Hemorrhagic Fever with Renal Syndrome / metabolism*
  • Hemorrhagic Fever with Renal Syndrome / virology
  • Humans
  • Luminescent Proteins / metabolism
  • Protein Multimerization*
  • Puumala virus / physiology*
  • Subcellular Fractions / metabolism*
  • Subcellular Fractions / virology
  • Vero Cells
  • Viral Envelope Proteins / chemistry
  • Viral Envelope Proteins / metabolism*

Substances

  • Bacterial Proteins
  • Glycoproteins
  • Luminescent Proteins
  • Viral Envelope Proteins
  • yellow fluorescent protein, Bacteria