Highly pathogenic avian influenza A virus H5N1 non-structural protein 1 is associated with apoptotic activation of the intrinsic mitochondrial pathway

Bian, Qian; Lu, Jing; Zhang, Li; Chi, Ying; Li, Yan; Guo, Hongxiong

To further corroborate the effect of the mitochondria/cytochrome c on the intrinsic apoptosis pathway inducted by the NS1 protein, western blotting was performed to detect the expression of cytochrome c in mitochondrial pellets and supernatants. The majority of cytochrome c expressed in mitochondrial pellets was isolated from the cells transfected with empty vector. It is noteworthy that the amount of cytochrome c was markedly decreased in the mitochondrial pellets following NS1-transfection for 24 h, whereas the amount of cytochrome c was markedly increased in the mitochondrial supernatant (Fig. 4) . These results indicate that NS1 may trigger the release of cytochrome c from mitochondria and that this effect is enhanced by STS.