Inefficient splicing of segment 7 and 8 mRNAs is an inherent property of influenza virus A/Brevig Mission/1918/1 (H1N1) that causes elevated expression of NS1 protein.
Influenza A virus encodes two segments (7 and 8) that produce mRNAs that can be spliced. We have investigated if naturally occurring sequence polymorphisms in the influenza A virus family affects splicing of these viral mRNAs, as that could potentially alter the NS1/NS2- and/or M1/M2-protein ratios. We compared splicing efficiency of segment 7 and 8 mRNAs of A/Brevig Mission/1918/1 (H1N1) and A/Netherlands/178/95 (H3N2), as well as various H5N1 avian strains. Results revealed that both segment 7 and 8 mRNAs of A/Brevig Mission/1918/1 (H1N1) were inefficiently spliced compared to other influenza virus segment 7 and 8 mRNAs. This resulted in production of higher levels of functional NS1 protein, which could potentially contribute to the pathogenic properties of the A/Brevig Mission/1918/1 (H1N1). We also show that A/Brevig Mission/1918/1 (H1N1) segment 8 mRNAs responded differently to overexpression of SR proteins than A/Netherlands/178/95 (H3N2).
Department of Laboratory Medicine, Section of Medical Microbiology, Lund University, 221 84 Lund, Sweden.
Ellenor
E
Backström Winquist
Samir
S
Abdurahman
Anna
A
Tranell
Sofia
S
Lindström
Susanne
S
Tingsborg
Stefan
S
Schwartz
D000595:Amino Acid Sequence; D005814:Genes, Viral; D057809:HEK293 Cells; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000235:genetics* / Q000378:metabolism*; D053122:Influenza A Virus, H3N2 Subtype / Q000235:genetics / Q000378:metabolism; D053124:Influenza A Virus, H5N1 Subtype / Q000235:genetics / Q000378:metabolism; D010957:Plasmids; D012326:RNA Splicing; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012367:RNA, Viral / Q000235:genetics; D017361:Viral Nonstructural Proteins / Q000096:biosynthesis* / Q000235:genetics* / Q000378:metabolism
C085820:INS1 protein, influenza virus; D012333:RNA, Messenger; D012367:RNA, Viral; D017361:Viral Nonstructural Proteins