%0 Journal Article %A Doceul, Virginie %A Charleston, Bryan %A Crooke, Helen %A Reid, Elizabeth %A Powell, Penny P. %A Seago, Julian %T The Npro product of classical swine fever virus interacts with IκBα, the NF-κB inhibitor %D 2008 %J Journal of General Virology, %V 89 %N 8 %P 1881-1889 %@ 1465-2099 %R https://doi.org/10.1099/vir.0.83643-0 %I Microbiology Society, %X Classical swine fever virus (CSFV) belongs to the genus Pestivirus and is the causative agent of classical swine fever, a haemorrhagic disease of pigs. The virus replicates in host cells without activating interferon (IFN) production and has been reported to be an antagonist of double-stranded RNA-induced apoptosis. The N-terminal protease (Npro) of CSFV is responsible for this evasion of the host innate immune response. In order to identify cellular proteins that interact with the Npro product of CSFV, a yeast two-hybrid screen of a human library was carried out, which identified IκBα, the inhibitor of NF-κB, a transcription factor involved in the control of apoptosis, the immune response and IFN production. The Npro–IκBα interaction was confirmed using yeast two-hybrid analysis and additional co-precipitation assays. It was also shown that Npro localizes to both the cytoplasmic and nuclear compartments in stably transfected cells and in CSFV-infected cells. Following stimulation by tumour necrosis factor alpha, PK-15 cell lines expressing Npro exhibited transient nuclear accumulation of pIκBα, but no effect of CSFV infection on IκBα localization or NF-κB p65 activation was observed. %U https://www.microbiologyresearch.org/content/journal/jgv/10.1099/vir.0.83643-0