Coronavirus envelope (E) protein remains at the site of assembly

Virology. 2015 Apr:478:75-85. doi: 10.1016/j.virol.2015.02.005. Epub 2015 Feb 27.

Abstract

Coronaviruses (CoVs) assemble at endoplasmic reticulum Golgi intermediate compartment (ERGIC) membranes and egress from cells in cargo vesicles. Only a few molecules of the envelope (E) protein are assembled into virions. The role of E in morphogenesis is not fully understood. The cellular localization and dynamics of mouse hepatitis CoV A59 (MHV) E protein were investigated to further understanding of its role during infection. E protein localized in the ERGIC and Golgi with the amino and carboxy termini in the lumen and cytoplasm, respectively. E protein does not traffic to the cell surface. MHV was genetically engineered with a tetracysteine tag at the carboxy end of E. Fluorescence recovery after photobleaching (FRAP) showed that E is mobile in ERGIC/Golgi membranes. Correlative light electron microscopy (CLEM) confirmed the presence of E in Golgi cisternae. The results provide strong support that E proteins carry out their function(s) at the site of budding/assembly.

Keywords: CLEM; Coronavirus; Envelope protein; FRAP; Live-cell imaging; Protein transport/localization; Virus assembly.

Publication types

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

MeSH terms

  • Animals
  • Cell Line
  • Cricetinae
  • Endoplasmic Reticulum / chemistry
  • Endoplasmic Reticulum / virology
  • Golgi Apparatus / chemistry
  • Golgi Apparatus / virology
  • Intracellular Membranes / chemistry*
  • Mice
  • Microscopy
  • Murine hepatitis virus / physiology*
  • Viral Envelope Proteins / analysis*
  • Virus Assembly*
  • Virus Release*

Substances

  • Viral Envelope Proteins