Combined Use of MS2 and PP7 Coat Fusions Shows that TIA-1 Dominates hnRNP A1 for K-SAM Exon Splicing Control

Figure 2

Structures of minigenes used. RSV: rous sarcoma virus long terminal repeat promoter. BGH: bovine growth hormone polyadenylation signal. C1 and C2: flanking exons. The K-SAM exon with its ESS is present in S3 and S4. In S1, S2, S5, and S6 internal K-SAM exon sequences including the ESS have been replaced by bacterial chloramphenicol acetyl tranferase sequences (CAT) split by insertion of sequences coding for single MS2 or PP7 RNA hairpins as shown. For S3-S6, sequences coding for single MS2 or PP7 RNA hairpins have been introduced into the downstream intron. IAS1: TIA-1 binding site. Minigenes are deleted for the BEK exon (▵BEK) but contain the K-SAM exon's ISEs IAS1 and and IAS3. S1 and S2 contain IAS2 also. Positions of minigene-specific primers P1 and P2 used for RT-PCR are shown.