Open AccessThe proapoptotic influenza A virus protein PB1‐F2 regulates viral polymerase activity by interaction with the PB1 protein
Author(s) -
Mazur Igor,
Anhlan Darisuren,
Mitzner David,
Wixler Ludmilla,
Schubert Ulrich,
Ludwig Stephan
Publication year - 2008
Publication title -
cellular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.542
H-Index - 138
eISSN - 1462-5822
pISSN - 1462-5814
DOI - 10.1111/j.1462-5822.2008.01116.x
Subject(s) - biology , polymerase , virology , influenza a virus , cytoplasm , viral structural protein , microbiology and biotechnology , open reading frame , virus , viral replication , gene , viral entry , genetics , peptide sequence
Summary The 11 th influenza A virus protein PB1‐F2 was previously shown to enhance apoptosis in response to cytotoxic stimuli. The 87 amino acid protein that is encoded by an alternative reading frame of the PB1 polymerase gene was described to localize to mitochondria consistent with its proapoptotic function. However, PB1‐F2 is also found diffusely distributed in the cytoplasm and in the nucleus suggesting additional functions of the protein. Here we show that PB1‐F2 colocalizes and directly interacts with the viral PB1 polymerase protein. Lack of PB1‐F2 during infection resulted in an altered localization of PB1 and decreased viral polymerase activity. Consequently, mutant viruses devoid of a functional PB1‐F2 reading frame exhibited a small plaque phenotype. Thus, we have identified a novel function of PB1‐F2 as an indirect regulator of the influenza virus polymerase activity via its interaction with PB1.