Expression of NS1 protein from five clinical specimens. (a). Amino acid alignment of NS1B(LEE)-FLAG (Lee-NS1), NS1B(136)-FLAG (136-NS1), NS1B(117)-FLAG (117-NS1), NS1B(132)-FLAG (132-NS1), NS1B(70)-FLAG (70-NS1) and NS1B(147)-FLAG (147-NS1) at amino acid positions 70–140. The linker domain (highlighted in blue) and the flanking RNA binding domain (RNABD) and effector domain (ED) are highlighted (b and c). Expression of the NS1 constructs in HEK 293T cells. At 16 h post transfection cells expressing NS1B(LEE)-FLAG, NS1B(136)-FLAG, NS1B(117)-FLAG, NS1B(132)-FLAG, NS1B(70)-FLAG and NS1B(147)-FLAG were immunoblotted with (b) anti-FLAG antibody or (c) αNS1 Cells transfected with empty pCAGGS Vector (V) or infected with Influenza B/Lee/40 (Lee(v)) are indicated. The NS1 protein (black arrows) and p23 (*) are highlighted.