Role of the NSs protein in the zoonotic capacity of Orthobunyaviruses

Zoonoses Public Health. 2009 Aug;56(6-7):285-96. doi: 10.1111/j.1863-2378.2008.01166.x.


The family Bunyaviridae contains over 350 named isolates, classified into five genera: Orthobunyavirus, Hantavirus, Nairovirus, Phlebovirus and Tospovirus. The Orthobunyavirus genus contains some 170 isolates that are mainly transmitted by mosquitoes and are responsible for a range of disease syndromes in humans including self-limiting febrile illness, encephalitis and haemorrhagic fever. The viruses have a tripartite, negative-sense RNA genome. Analyses of viruses in four serogroups (Bunyamwera, California, Group C and Simbu) showed that the smallest (S) RNA segment encodes the nucleocapsid protein (N) and a non-structural protein called (NSs). The NSs protein of Bunyamwera virus (BUNV) has been shown to play a role in shut-off of host cell protein synthesis in mammalian cells, but no protein shut-off is observed in BUNVinfected mosquito cells (Aedes albopictus C6/36 cells). Protein shut-off in infected mammalian cells is achieved by global inhibition of RNA polymerase II-mediated transcription and enables the virus to overcome the host innate immune response. As innate defence mechanisms constitute a significant barrier to virus infection of different hosts, NSs would appear to play a key role in determining the zoonotic capacity of orthobunyaviruses.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aedes / virology
  • Animals
  • Bunyaviridae Infections / transmission*
  • Bunyaviridae Infections / veterinary*
  • Bunyaviridae Infections / virology
  • Humans
  • Nucleocapsid Proteins / genetics
  • Nucleocapsid Proteins / physiology*
  • Orthobunyavirus / pathogenicity*
  • Viral Nonstructural Proteins / genetics
  • Viral Nonstructural Proteins / physiology*
  • Zoonoses / virology*


  • N protein, Bunyamwera bunyavirus
  • NSs protein, Bunyamwera bunyavirus
  • Nucleocapsid Proteins
  • Viral Nonstructural Proteins