Repression of divergent noncoding transcription by a sequence-specific transcription factor

Abstract

Many active eukaryotic gene promoters exhibit divergent noncoding transcription, but the mechanisms restricting expression of these transcripts are not well understood.Here we demonstrate how a sequence-specific transcription factor represses divergent noncoding transcription at highly expressed genes in yeast. We find that depletion of the transcription factor Rap1 induces noncoding transcription in a large fraction of Rap1 regulated gene promoters. Specifically, Rap1 prevents transcription initiation at cryptic promoters near its binding sites, which is uncoupled from transcription regulation in the protein-coding direction. We further provide evidence that Rap1 acts independently of chromatin-based mechanisms to repress cryptic or divergent transcription. Finally, we show that divergent transcription in the absence of Rap1 is elicited by the RSC chromatin remodeller. We propose that a sequencespecific transcription factor limits access of basal transcription machinery to regulatory elements and adjacent sequences that act as divergent cryptic promoters, thereby providing directionality towards productive transcription.

Perturbing proteomes at single residue resolution using base editing

“…Albuquerque et al 2008;Holt et al 2009), but the functional importance of this phosphorylation 271 has not been explored yet. Residue T486 is located in a disordered region in the DNA binding 272 domains(Konig et al 1996), which part of the only RAP1 fragment essential for cell growth 273(Graham et al 1999;Wu et al 2018). 274…”