Splicing of influenza virus matrix protein mRNA expressed from a simian virus 40 recombinant.

摘要: Influenza virus RNA segment 7 encodes two proteins, M1 and M2, depending on the optional removal of an intron from its primary transcript. To investigate mechanism this regulated splicing, influenza cDNA was cloned under control simian 40 (SV40) early promoter poly(A) signals in SV40 recombinant (SVM), expressed COS-1 cells. Expression both M2 proteins detected SVM-infected cells, suggesting (i) appropriate splicing events to generate mRNA occur these cells (ii) significant amounts unspliced are transported cytoplasm. Analysis relative proportion mRNA3 indicated that use alternative 5′ splice sites is reversed compared with those infected virus. In addition, a different intranuclear distribution transcripts found each type cell. We speculate differences efficiency site choice might be related subnuclear localizations synthesized by transcriptional machineries.