Senataxin Promotes RNA Polymerase II Elongation [Hap1_DRBrelease_TTseq]

Senataxin (SETX) is recognized as a critical regulator of RNA Polymerase II (RNAPII) transcription and plays a pivotal role in maintaining genomic stability. Despite its importance, the direct in vivo functions of SETX remain inadequately characterized. Employing the degradation tag (dTAG) system for acute protein depletion, we demonstrate that SETX does not influence transcription termination but significantly enhances RNAPII elongation. Through in vitro reconstitution assays, we show that SETX actively drives RNAPII forward across complex transcriptional landscapes, akin to the way bacterial ribosomes mitigate transcriptional pauses. In vivo analyses further reveal an accumulation of pausing RNAPII at early transcription stages and a corresponding increase in R-loop formation at these sites following SETX depletion. These insights not only redefine our understanding of SETX's role in transcriptional regulation but also highlight its potential as a therapeutic target in disorders linked to transcriptional dysregulation.