Apoptotic and Early Innate Immune Responses to PB1-F2 Protein of Influenza A Viruses Belonging to Different Subtypes in Human Lung Epithelial A549 Cells

Figure 1

PB1-F2 sequence comparison and structural predictions. (a) Amino acid multialignment of the five PB1-F2 variants included in this study. PB1-F2 proteins analyzed in silico in this study from the influenza viruses are abbreviated as follows: A/chicken/India/WBNIV2653/2008 (H5N1-WB); A/chicken/India/NIV9743/2007 (H5N1-M); A/chicken/India/WB-NIV1057231/2010 (H9N2); A/aquatic bird/India/NIV-17095/2007 (H11N1); and A/WSN/1933 (H1N1). Eight amino acid residues which have been reported in literature to have significance in enhancing apoptosis and inflammation have been marked with asterisk. L62, R75, R79, and L82 are reported as inflammatory motifs, N66S as a pathogenic marker, L69 and L75 important for mitochondrial localization, K73 and R75 minimally required for apoptosis via mitochondria. (b) Secondary structure predictions were obtained with the software RaptorX program. Straight line structure represents the loop, cylinder represents the α Helix, and arrow head marks the β sheet structure.

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