Subcellular localization of the severe acute respiratory syndrome coronavirus nucleocapsid protein

J Gen Virol. 2005 Dec;86(Pt 12):3303-3310. doi: 10.1099/vir.0.81076-0.


The coronavirus nucleocapsid (N) protein is a viral RNA-binding protein with multiple functions in terms of virus replication and modulating cell signalling pathways. N protein is composed of three distinct regions containing RNA-binding motif(s), and appropriate signals for modulating cell signalling. The subcellular localization of severe acute respiratory syndrome coronavirus (SARS-CoV) N protein was studied. In infected cells, SARS-CoV N protein localized exclusively to the cytoplasm. In contrast to the avian coronavirus N protein, overexpressed SARS-CoV N protein remained principally localized to the cytoplasm, with very few cells exhibiting nucleolar localization. Bioinformatic analysis and deletion mutagenesis coupled to confocal microscopy and live-cell imaging, revealed that SARS-CoV N protein regions I and III contained nuclear localization signals and region II contained a nucleolar retention signal. However, cytoplasmic localization was directed by region III and was the dominant localization signal in the protein.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Cell Nucleolus / chemistry
  • Chlorocebus aethiops
  • Computational Biology
  • Cytoplasm / chemistry*
  • Microscopy, Confocal
  • Molecular Sequence Data
  • Nuclear Localization Signals
  • Nucleocapsid Proteins / analysis*
  • Nucleocapsid Proteins / chemistry
  • Nucleocapsid Proteins / genetics
  • Protein Structure, Tertiary
  • SARS Virus / genetics
  • SARS Virus / physiology*
  • Sequence Deletion
  • Sequence Homology
  • Vero Cells


  • Nuclear Localization Signals
  • Nucleocapsid Proteins
  • nucleocapsid protein, Coronavirus