Structure and Novel Functional Mechanism of Drosophila SNF in Sex-Lethal Splicing
Figure 1
In vitro splicing of Sxl pre-mRNA.
In vitro transcribed, radioactively-labeled RNA encompassing exon 3 to exon 4 (E3-4) of Sxl pre-mRNA was used as the in vitro splicing substrate. The positions of substrate E3-4 and splicing-intermediate RNAs are represented schematically on the right-hand side of the panel. Boxes indicate introns; Lines indicate exons; Loops indicate lariat structures. (A) The effect of the general splicing factor SC35 enhanced efficiency of the splicing reaction (lanes 1–3); and the effect of SXL at increasing concentrations on the splicing of E3-4 (lanes 4–8). (B) Effects of SNF on the splicing of E3-4. Lanes 1 to 4: addition of 0, 3, 9, or 15 µM SNF protein, respectively; lanes 5 to 10, effects of human U1A protein (hU1A) and known polypyrimidine binding proteins U2AF65, PTB, and hnRNP L on the splicing reaction.