Hinokiflavone is identified as a splicing modulator that blocks progression from spliceosome complex A to complex B and inhibits SUMO protease SENP1, causing hyper-SUMOylation affecting 6 U2 snRNP proteins.
Viewing the dynamic interactions of individual spliceosomal subcomplexes with single pre-messenger RNA molecules reveals how nearby flanking splice sites accelerate pre-spliceosome assembly and the splicing of multi-intron pre-mRNAs.
Hundreds of cell growth and stress response genes are controlled by a rare small RNA component of an ancient splicing machinery, providing a raison d'être for its previously unexplained evolutionary conservation.
Stalling spliceosome assembly at a novel step before Bact complex formation reveals new insights into the extensive RNP rearrangements and compositional changes that accompany the intricate process of spliceosome activation.
Structural and functional analyses show how the spliceosomal Prp3 protein concomitantly binds double- and single- stranded regions in U4/U6 di-snRNAs and serves to stabilize the U4/U6•U5 tri-snRNP for splicing.