Schematic draw of the pre-mRNA splicing processes and components of tri-snRNP related to this study.

Abstract

<p>Exons and one intron are represented by boxes and solid line, respectively. Base pairing of U1 to 5’ss and recognition of BP by U2 (formation of complex A) are followed by the integration of preformed U4/U6-U5 tri-snRNP to form complex B. Whereas Prp4 and Prp31 are components of U4/U6 snRNP, Brr2, Prp8, and Prp6 are components of U5 snRNP. Phosphorylation of Prp6 and Prp31 by Prp4 is associated with the activation of B-complex (complex B^act). U1, U4, Prp4, Prp6, and Prp31 are released from the activated spliceosome that catalyzes two sequential transesterifications reactions for intron splicing.</p