FIG. 7.

Reconstitution of splicing inhibition by addition of hnRNP A/B proteins to depleted extracts. HS1-ESSV and HS1-ESSVx RNA substrates were spliced in ESSV RNA-bead-depleted HeLa cell nuclear extracts in the presence of 900 ng of the indicated hnRNPs. Splicing was also carried out after the addition of the same amounts of control proteins: UP1-GST (two RNA recognition motifs of hnRNP A1 fused to GST) in lanes 11 and 12 and GST alone in lanes 13 and 14. The positions of the precursor and the spliced product are marked.