The Sen1 Helicase Prevents Spurious Transcription by Controlling Genome-Wide Transcription Termination by RNAPII

RNA Polymerase II (RNAPII) termination for transcripts containing a polyadenylation signal (PAS) is thought to differ mechanistically from termination for PAS-independent RNAPII transcripts such as sn(o)RNAs. In a screen for factors required for PAS-dependent termination, we identified Sen1, a putative helicase known primarily for its role in PAS-independent termination. We show that Sen1 is required for termination on hundreds of protein-coding genes and suppresses cryptic transcription from nucleosome-free regions on a genomic scale. These effects often overlap with but are also often distinct from those caused by Nrd1 depletion, which also impacts termination of protein-coding and cryptic transcripts, including many genic antisense transcripts. Sen1 controls termination through its helicase activity and stimulates recruitment of factors previously implicated in both PAS-dependent (Rna14, Rat1) and PAS-independent (Nrd1) termination. Thus, RNAPII termination for both protein-coding genes and cryptic transcripts is dependent on multiple pathways. The 2 RNAPII datasets were produced in duplicates and the Sen1 and Nrd1 datasets in triplicates (all IP/Input).