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Differential Localization and Function of PB1-F2 Derived from Different Strains of Influenza A Virus.
- Source :
-
Journal of Virology . Oct2010, Vol. 84 Issue 19, p10051-10062. 12p. - Publication Year :
- 2010
-
Abstract
- PB1-F2 is a viral protein that is encoded by the PB1 gene of influenza A virus by alternative translation. It varies in length and sequence context among different strains. The present study examines the functions of PB1-F2 proteins 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 displayed no ability to enhance apoptosis. 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 compared with the level of mitochondrial localization of wild-type H5N1 PB1-F2, suggesting that a Leu-rich sequence in the C terminus is important for targeting of mitochondria. However, H5N1 PB1-F2 contributes to viral RNP activity, which is responsible for viral RNA replication. Lastly, although the swine-origin influenza virus (S-OIV) contained a truncated form of PB1-F2 (12 amino acids [aa]), potential mutation in the future may 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 viral RNP activity. The plaque size and growth curve of the viruses with and without S-OIV PB1-F2 differed greatly. The PB1-F2 protein has various lengths, amino acid sequences, cellular localizations, and functions in different strains, which result in strain-specific pathogenicity. Such genetic and functional diversities make it flexible and adaptable in maintaining the optimal replication efficiency and virulence for various strains of influenza A virus. [ABSTRACT FROM AUTHOR]
- Subjects :
- *INFLUENZA A virus
*MITOCHONDRIA
*VIRAL proteins
*APOPTOSIS
*AMINO acid analysis
Subjects
Details
- Language :
- English
- ISSN :
- 0022538X
- Volume :
- 84
- Issue :
- 19
- Database :
- Academic Search Index
- Journal :
- Journal of Virology
- Publication Type :
- Academic Journal
- Accession number :
- 61216605
- Full Text :
- https://doi.org/10.1128/JVI.00592-10