tetano
Editor, Senior Moderator
J Virol. 2012 Dec 12. [Epub ahead of print]
Identification of novel influenza A virus proteins translated from PA mRNA.
Muramoto Y, Noda T, Kawakami E, Akkina R, Kawaoka Y.
Source
Division of Virology, Department of Microbiology and Immunology, Institute of Medical Science, University of Tokyo, Tokyo 108-8639, Japan.
Abstract
Many replication events are involved in the influenza A virus life cycle, which are accomplished by different virus proteins with specific functions. However, because the size of influenza virus genome is limited, the virus uses different mechanisms to express multiple viral proteins from a single gene segment. The M2 and NS2 proteins are produced by splicing and several novel influenza A virus proteins, such as PB1-F2, PB1-N40, and PA-X have recently been identified. Here, we identified novel PA-related proteins in influenza A virus-infected cells. These newly identified proteins are translated from the eleventh and thirteenth in-frame AUG codons in the PA mRNA and are, therefore, N-terminally truncated forms of PA, which we named PA-N155 and PA-N182, respectively. The eleventh and thirteenth AUG codons are highly conserved among influenza A viruses, and the PA-N155 and PA-N182 proteins were detected in cells infected with various influenza A viruses isolated from different host species, suggesting the expression of these N-truncated PAs is universal in nature among influenza A viruses. These N-truncated PAs did not show polymerase activity when expressed together with PB1 and PB2; however, mutant viruses lacking the N-truncated PAs replicated more slowly in cell culture and had lower pathogenicity in mice than did wild-type virus. These results suggest that these novel PA-related proteins likely possess important functions in the replication cycle of influenza A virus.
PMID:
23236060
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/23236060
Identification of novel influenza A virus proteins translated from PA mRNA.
Muramoto Y, Noda T, Kawakami E, Akkina R, Kawaoka Y.
Source
Division of Virology, Department of Microbiology and Immunology, Institute of Medical Science, University of Tokyo, Tokyo 108-8639, Japan.
Abstract
Many replication events are involved in the influenza A virus life cycle, which are accomplished by different virus proteins with specific functions. However, because the size of influenza virus genome is limited, the virus uses different mechanisms to express multiple viral proteins from a single gene segment. The M2 and NS2 proteins are produced by splicing and several novel influenza A virus proteins, such as PB1-F2, PB1-N40, and PA-X have recently been identified. Here, we identified novel PA-related proteins in influenza A virus-infected cells. These newly identified proteins are translated from the eleventh and thirteenth in-frame AUG codons in the PA mRNA and are, therefore, N-terminally truncated forms of PA, which we named PA-N155 and PA-N182, respectively. The eleventh and thirteenth AUG codons are highly conserved among influenza A viruses, and the PA-N155 and PA-N182 proteins were detected in cells infected with various influenza A viruses isolated from different host species, suggesting the expression of these N-truncated PAs is universal in nature among influenza A viruses. These N-truncated PAs did not show polymerase activity when expressed together with PB1 and PB2; however, mutant viruses lacking the N-truncated PAs replicated more slowly in cell culture and had lower pathogenicity in mice than did wild-type virus. These results suggest that these novel PA-related proteins likely possess important functions in the replication cycle of influenza A virus.
PMID:
23236060
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/23236060