Nucleolar localization of influenza A NS1: striking differences between mammalian and avian cells
1 INRA, UMR 1225, Ecole nationale vétérinaire de Toulouse, F-31076 Toulouse, France
2 Université de Toulouse; ENVT; UMR 1225; F-31076 Toulouse, France
3 Centre for Biomolecular Sciences, School of Biology, University of St. Andrews, North Haugh, St. Andrews, Fife KY16 9ST, UK
Virology Journal 2010, 7:63 doi:10.1186/1743-422X-7-63Published: 17 March 2010
In mammalian cells, nucleolar localization of influenza A NS1 requires the presence of a C-terminal nucleolar localization signal. This nucleolar localization signal is present only in certain strains of influenza A viruses. Therefore, only certain NS1 accumulate in the nucleolus of mammalian cells. In contrast, we show that all NS1 tested in this study accumulated in the nucleolus of avian cells even in the absence of the above described C-terminal nucleolar localization signal. Thus, nucleolar localization of NS1 in avian cells appears to rely on a different nucleolar localization signal that is more conserved among influenza virus strains.