Nucleocapsid-independent specific viral RNA packaging via viral envelope protein and viral RNA signal

J Virol. 2003 Mar;77(5):2922-7. doi: 10.1128/jvi.77.5.2922-2927.2003.

Abstract

For any of the enveloped RNA viruses studied to date, recognition of a specific RNA packaging signal by the virus's nucleocapsid (N) protein is the first step described in the process of viral RNA packaging. In the murine coronavirus a selective interaction between the viral transmembrane envelope protein M and the viral ribonucleoprotein complex, composed of N protein and viral RNA containing a short cis-acting RNA element, the packaging signal, determines the selective RNA packaging into virus particles. In this report we show that expressed coronavirus envelope protein M specifically interacted with coexpressed noncoronavirus RNA transcripts containing the short viral packaging signal in the absence of coronavirus N protein. Furthermore, this M protein-packaging signal interaction led to specific packaging of the packaging signal-containing RNA transcripts into coronavirus-like particles in the absence of N protein. These findings not only highlight a novel RNA packaging mechanism for an enveloped virus, where the specific RNA packaging can occur without the core or N protein, but also point to a new, biologically important general model of precise and selective interaction between transmembrane proteins and specific RNA elements.

Publication types

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

MeSH terms

  • Animals
  • Coronavirus M Proteins
  • Mice
  • Murine hepatitis virus / genetics
  • Murine hepatitis virus / metabolism*
  • Nucleocapsid / metabolism*
  • Nucleocapsid Proteins
  • RNA, Viral / chemistry
  • RNA, Viral / genetics
  • RNA, Viral / metabolism*
  • Signal Transduction*
  • Viral Matrix Proteins / metabolism*
  • Virion / metabolism
  • Virus Assembly*

Substances

  • Coronavirus M Proteins
  • Nucleocapsid Proteins
  • RNA, Viral
  • Viral Matrix Proteins
  • nucleocapsid protein, Hepatitis virus