Fig. 4

Distinct BPS usage of wt BRAF from mt BRAF RNA splicing identified by lariat RT-PCR. a Strategy of lariat RT-PCR for branch point mapping. Splicing lariats or lariat-intermediates from in vitro splicing assays were reverse-transcribed by a primer R. PCR amplification of the RT products was carried out by a primer set of F₁ and R, and then nested by another primer set of F₂ and R. b Lariat RT-PCR products (arrows) of wt (left) and mt (right) BRAF RNA splicing. c The mapped branch points from TA cloning and sequencing of the wt and mt BRAF lariats and lariat-intermediates. d Frequency of the mapped branch points from wt and mt BRAF splicing by lariat RT-PCR in combination with TA cloning and sequencing. e Illustration of the mapped branch points in the intron 8 used for RNA splicing of the wt and mt BRAF