Over-expression of severe acute respiratory syndrome coronavirus 3b protein induces both apoptosis and necrosis in Vero E6 cells
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Date
2006
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier
Abstract
The genome of the severe acute respiratory syndrome coronavirus encodes for eight accessory viral proteins with no known homologues in other
coronaviruses. One of these is the 3b protein, which is encoded by the second open reading frame in subgenomic RNA 3 and contains 154 amino
acids. Here, a detailed time-course study was performed to compare the apoptosis and necrosis profiles induced by full-length 3b, a 3b mutant
that was deleted by 30 amino acids from the C terminus (3b 124-154) and the classical apoptosis inducer, Bax. Our results showed that Vero E6
cells transfected with a construct for expressing 3b underwent necrosis as early as 6 h after transfection and underwent simultaneous necrosis and
apoptosis at later time-points. At all the time-points analysed, the apoptosis induced by the expression of 3b was less than the level induced by Bax
but the level of necrosis was comparable. The 3b 124-154 mutant behaves in a similar manner indicating that the localization of the 3b protein
does not seems to be important for the cell-death pathways since full-length 3b is localized predominantly to the nucleolus, while the mutant is
found to be concentrated in the peri-nuclear regions. To our knowledge, this is the first report of the induction of necrosis by a SARS-CoV protein.
Description
Keywords
Coronavirus, Respiratory syndrome, Necrosis, Apoptosis, Protein
Citation
Khan, S., et al. (2006). Over-expression of severe acute respiratory syndrome coronavirus 3b protein induces both apoptosis and necrosis in Vero E6 cells. Virus Research, 122: 20-27