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Updated: Aug 21, 2026

Artificial RNA Polymerase II Elongation Complexes for Dissecting Co-transcriptional RNA Processing Events
Published on: May 13, 2019
RNA polymerase II carboxy-terminal domain phosphorylation is required for cotranscriptional pre-mRNA splicing and
Gregory Bird1, Diego A R Zorio, David L Bentley
1Department of Biochemistry and Molecular Genetics, University of Colorado Health Science Center at Fitzsimons, P.O. Box 6511, Aurora, CO 80045, USA.
Abstract:
We investigated the role of RNA polymerase II (pol II) carboxy-terminal domain (CTD) phosphorylation in pre-mRNA processing coupled and uncoupled from transcription in Xenopus oocytes. Inhibition of CTD phosphorylation by the kinase inhibitors 5,6-dichloro-1beta-D-ribofuranosyl-benzimidazole and H8 blocked transcription-coupled splicing and poly(A) site cleavage. These experiments suggest that pol II CTD phosphorylation is required for efficient pre-mRNA splicing and 3'-end formation in vivo. In contrast, processing of injected pre-mRNA was unaffected by either kinase inhibitors or alpha-amanitin-induced depletion of pol II. pol II therefore does not appear to participate directly in posttranscriptional processing, at least in frog oocytes. Together these experiments show that the influence of the phosphorylated CTD on pre-mRNA splicing and 3'-end processing is mediated by transcriptional coupling.
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