tetano
Editor, Senior Moderator
J Virol. 2010 Jul 21. [Epub ahead of print]
Differential localization and function of PB1-F2 derived from different strains of influenza A virus.
Chen CJ, Chen GW, Wang CH, Huang CH, Wang YC, Shih SR.
Research Center for Emerging Viral Infections; Graduate Institute of Biomedical Sciences; Department of Medical Biotechnology and Laboratory Science; Department of Computer Science and Information Engineering, Chang Gung University, Tao-Yuan, Taiwan, R.O.C; Department of Veterinary Medicine, National Taiwan University; Institute of Preventive Medicine, National Defense Medical Center, Taipei, Taiwan, R.O.C.
Abstract
PB1-F2 is a viral protein that is encoded by PB1 gene of influenza A virus by alternative translation. It varies in lengths and sequence contexts amongst different strains. This study examines the functions of PB1-F2 that was derived from various human and avian viruses. While H1N1 PB1-F2 was found to target mitochondria and enhance apoptosis, H5N1 PB1-F2 surprisingly did not localize specifically to mitochondria and display no apoptosis enhancement. Introducing Leu into positions 69 (Q69L) and 75 (H75L) in the C-terminus of H5N1 PB1-F2 drove 40.7 % of the protein to localize to mitochondria comparing with that of wild-type H5N1 PB1-F2, suggesting that Leu-rich sequence in C-terminus is important for mitochondria targeting. However, H5N1 PB1-F2 contributes to viral RNP activity that is responsible for viral RNA replication. Lastly, although the swine-origin influenza virus (S-OIV) contained a truncated form of PB1-F2 (12-aa), potential mutation may in the future enable it to contain a full-length product. Therefore, the functions of this putative S-OIV PB1-F2 (87-aa) were also investigated. Although this PB1-F2 from the mutated S-OIV shares only 54% amino acid sequence identity with that of seasonal H1N1 virus, it also increased the viral RNP activity. The plaque size and growth curve of the viruses with and without S-OIV PB1-F2 differed greatly. PB1-F2 contains various lengths, amino acid sequences, cellular localizations and functions, which in terms displays strain-specific pathogenicity. Such genetic and functional diversity makes it flexible and adaptable in maintaining optimal replication efficiency and virulence for various strains of influenza A virus.
PMID: 20660199 [PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/20660199
Differential localization and function of PB1-F2 derived from different strains of influenza A virus.
Chen CJ, Chen GW, Wang CH, Huang CH, Wang YC, Shih SR.
Research Center for Emerging Viral Infections; Graduate Institute of Biomedical Sciences; Department of Medical Biotechnology and Laboratory Science; Department of Computer Science and Information Engineering, Chang Gung University, Tao-Yuan, Taiwan, R.O.C; Department of Veterinary Medicine, National Taiwan University; Institute of Preventive Medicine, National Defense Medical Center, Taipei, Taiwan, R.O.C.
Abstract
PB1-F2 is a viral protein that is encoded by PB1 gene of influenza A virus by alternative translation. It varies in lengths and sequence contexts amongst different strains. This study examines the functions of PB1-F2 that was derived from various human and avian viruses. While H1N1 PB1-F2 was found to target mitochondria and enhance apoptosis, H5N1 PB1-F2 surprisingly did not localize specifically to mitochondria and display no apoptosis enhancement. Introducing Leu into positions 69 (Q69L) and 75 (H75L) in the C-terminus of H5N1 PB1-F2 drove 40.7 % of the protein to localize to mitochondria comparing with that of wild-type H5N1 PB1-F2, suggesting that Leu-rich sequence in C-terminus is important for mitochondria targeting. However, H5N1 PB1-F2 contributes to viral RNP activity that is responsible for viral RNA replication. Lastly, although the swine-origin influenza virus (S-OIV) contained a truncated form of PB1-F2 (12-aa), potential mutation may in the future enable it to contain a full-length product. Therefore, the functions of this putative S-OIV PB1-F2 (87-aa) were also investigated. Although this PB1-F2 from the mutated S-OIV shares only 54% amino acid sequence identity with that of seasonal H1N1 virus, it also increased the viral RNP activity. The plaque size and growth curve of the viruses with and without S-OIV PB1-F2 differed greatly. PB1-F2 contains various lengths, amino acid sequences, cellular localizations and functions, which in terms displays strain-specific pathogenicity. Such genetic and functional diversity makes it flexible and adaptable in maintaining optimal replication efficiency and virulence for various strains of influenza A virus.
PMID: 20660199 [PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/20660199