RT Journal Article
SR Electronic
T1 Type I PRMTs and PRMT5 Independently Regulate Both snRNP Arginine Methylation and Post-Transcriptional Splicing
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2020.11.18.389288
DO 10.1101/2020.11.18.389288
A1 Maxim I. Maron
A1 Emmanuel S. Burgos
A1 Varun Gupta
A1 Alyssa D. Casill
A1 Brian Kosmyna
A1 Hongshan Chen
A1 Matthew J. Gamble
A1 Charles C. Query
A1 David Shechter
YR 2020
UL http://biorxiv.org/content/early/2020/11/19/2020.11.18.389288.abstract
AB Protein arginine methyltransferases (PRMTs) methylate histones, splicing factors, and many other nuclear proteins. Type I enzymes (PRMT1-4,6,8) catalyze mono- (Rme1/MMA) and asymmetric (Rme2a/ADMA) dimethylation; Type II enzymes (PRMT5,9) catalyze mono- and symmetric (Rme2s/SDMA) dimethylation. Misregulation of PRMTs in multiple types of cancers is associated with aberrant gene expression and RNA splicing. To understand the specific mechanisms of PRMT activity in splicing regulation, we treated cells with the PRMT5 inhibitor GSK591 and the Type I inhibitor MS023 and probed their transcriptomic consequences. We discovered that Type I PRMTs and PRMT5 inversely regulate core spliceosomal Sm protein Rme2s and intron retention. Loss of Sm Rme2s is associated with the accumulation of polyadenylated RNA containing retained introns and snRNPs on chromatin. Conversely, increased Sm Rme2s correlates with decreased intron retention and chromatin-association of intron-containing polyadenylated RNA. Using the newly developed SKaTER-seq model, comprehensive and quantitative analysis of co-transcriptional splicing revealed that either Type I PRMT or PRMT5 inhibition resulted in slower splicing rates. Surprisingly, altered co-transcriptional splicing kinetics correlated poorly with ultimate changes in alternatively spliced mRNA. Quantitation of retained intron decay following inhibition of nascent transcription revealed that Type I PRMTs and PRMT5 reciprocally regulate post-transcriptional splicing efficiency.Competing Interest StatementThe authors have declared no competing interest.