Figure 2.
The F2 20210*A, F2 20210*C, F2 20210*T, and F2 20221*T mutations enhance F2 mRNA 3′end processing efficiency. (A) Schematic drawing of the constructs with tandem 3′end formation signals. (B) Northern blot of cells cotransfected with the tandem constructs and the WT+300 E3 control plasmid. The lower bands (5′ site) on the autoradiograph represent mRNAs that are cleaved and polyadenylated at the mutated 5′ site, whereas the upper bands (3′ site) correspond to transcripts that are processed at the reference 3′ site. Lane 6 shows the mRNA of cells transfected with the WT+300 E3 control only. The numbers shown below the panel represent the ratio of mRNA processed at the 5′ site relative to that processed at the 3′ site. The signals were quantified by phosphoimaging.