The team of JC Andrau team has characterized at the genomic scale that a CTD-depleted RNA Polymerase II can still transcribe but cannot terminate transcription anymore. This results in a massive read-through phenotype, over hundreds of kb, at both ends of transcriptional units. Further on, without CTD, Pol II loses its interaction with both Mediator and Integrator complexes that most likely contribute to the observed phenotype. This study set a standard for future studies on the CTD and strongly suggest that control of termination is one of main, and up to now largely ignored, function of the RNA Polymerase II CTD.
These results are published in the journal Embo reports.
RNA polymerase II CTD is dispensable for transcription and required for termination in human cells. Yahia Y, Pigeot A, El Aabidine AZ, Shah N, Karasu N, Forné I, Krebs S, Blum H, Esnault C, Sexton T, Imhof A, Eick D, Andrau JC. EMBO Rep. 2023 Jul 10:e56150.
Transcription without CTD results in a massive termination defect
Working model for the readthrough phenotype associated with Pol II mutants. In CTD-depleted mutants of Pol II (CTD-5), Mediator and Integrator complexes are lost in proteomic experiments and likely result in loss of termination control at both ends of the transcription unit.