POISON EXON SPLICING REGULATES A COORDINATED NETWORK OF SR PROTEIN EXPRESSION DURING DIFFERENTIATION AND TUMORIGENESIS_Leclair et al Molecular Cell 2020
ABSTRACT: The RNA isoform repertoire is regulated by splicing-factor (SF) expression, and alterations in SF-levels are associated with disease. SFs contain ultraconserved poison exon (PE) sequences, which exhibit greater identity across species than nearby coding exons, yet their physiological role and molecular regulation is incompletely understood. We show that PEs in SR proteins, a family of 14 essential SFs, are differentially spliced during iPSC differentiation and in tumors vs. normal tissues. We uncover an extensive cross-regulatory network of SR proteins controlling their expression via alternative splicing coupled to nonsense-mediated decay. We define sequences that regulate PE inclusion and protein expression of the oncogenic SF TRA2β using an RNA-targeting CRISPR screen. We demonstrate location-dependency of RS domain activity on the regulation of the TRA2β-PE using CRISPR-artificial SFs. Finally, we develop splice-switching antisense oligonucleotides to reverse the increased skipping of TRA2β-PE detected in breast tumors, altering breast cancer cell viability, proliferation, and migration. DATASET OVERVIEW: Wet lab data including gel and microscopy images for this study. Dataset is organized by figure and specific methods for each experiment can be found in the main manuscript. For each figure a pdf file is provided with each of the images labelled along with the corresponding tiff file. Questions/comments regarding this data set can be forwarded to the corresponding author Olga Anczukow (email@example.com) or the first author Nathan Leclair (firstname.lastname@example.org).