The INO80 ATP-dependent chromatin remodelling complex alleviates stalled Polymerase II to promote non-coding RNA transcription termination

ABSTRACT Co-transcriptional RNA quality control is essential for gene expression. However, its regulation remains poorly understood. Here, we report that the evolutionarily conserved ATP-dependent chromatin remodelling INO80 complex promotes transcription termination by the non-coding RNA quality control pathway in S. cerevisiae . Loss of INO80 leads to accumulation of stalled RNA Polymerase II preferentially at promoter-proximal pausing sites, compromising Pol II processivity and hindering transcription elongation. We reveal that binding of RNA surveillance and non-coding transcription termination factors to promoter-proximal mRNA regions is associated with increased promoter-proximal pausing. INO80 counteracts promoter-proximal stalling of genes attenuated by the Nrd1-Nab3-Sen1 (NNS) non-coding transcription termination complex, promoting their expression. We show that INO80 interacts with Nrd1 and the Nab2 RNA surveillance factor in vivo . Absence of INO80 leads to defective transcription termination by the Nrd1-Nab3-Sen1 (NNS) complex. We demonstrate that INO80 facilitates the recruitment of Nab2 at non-coding transcription termination sites and its association with promoter-proximally terminated mRNA transcripts. Finally, we provide evidence that INO80 promotes the release of stalled RNA Polymerase II from a non-coding transcription termination site. Collectively, our work suggests that the INO80 complex regulates transcription by removal of stalled Polymerase, implicating a chromatin-based mechanism for non-coding and premature transcription termination in gene expression.