High-resolution mapping of transcribing RNAPII by CRAC in a wt or a sen1T1623E mutant
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ABSTRACT: Manuscript title: Modulated termination of non-coding transcription partakes in the regulation of gene expression Here we report high-resolution analyses of transcribing RNAPII in either a wild-type (WT) background or a sen1T1623E mutant, which harbours a substitution that mimics the phosphorylation at threonine 1623. Sen1 is a well-characterized transcription termination factor for RNAPII-dependent non-coding genes in budding yeast. Here we show that the T1623E phosphomimetic mutation induces moderate but widespread termination defects at target non-coding genes, strongly suggesting that phosphoryation at T1623 modulates negatively Sen1 transcription termination activity.
Project description:Here we report high-resolution analyses of transcribing RNAPIII in either a wild-type (WT) background or a Nrd1 auxin-inducible degron (AID) strain in which Nrd1 can be rapidly depleted upon addition of the auxin analogue Indole-3-acetic acid (IAA). Nrd1 functions together with Sen1 in transcription termination at RNAPII-dependent non-coding genes. Here we show that depletion of Nrd1 does not affect transcription termination at RNAPIII-dependent genes, indicating that Nrd1 is not an RNAPIII transcription termination factor.
Project description:Pervasive transcription is a widespread phenomenon leading to the production of a plethora of non-coding RNAs (ncRNAs) without apparent function. Pervasive transcription poses a risk that needs to be controlled to prevent the perturbation of gene expression. In yeast, the highly conserved helicase Sen1 restricts pervasive transcription by inducing termination of non-coding transcription. However, the mechanisms underlying the specific function of Sen1 at ncRNAs are poorly understood. Here we identify a motif in an intrinsically disordered region of Sen1 that mimics the phosphorylated carboxy terminal domain (CTD) of RNA polymerase II and characterize structurally its recognition by the CTD-interacting domain of Nrd1, an RNA-binding protein that binds specific sequences in ncRNAs. In addition, we show that Sen1-dependent termination strictly requires the recognition of the Ser5-phosphorylated form of the CTD by the N-terminal domain of Sen1. Furthermore, we find that the N-terminal and the C-terminal domains of Sen1 can mediate intra-molecular interactions. Our results shed light onto the network of protein-protein interactions that control termination of non-coding transcription by Sen1.
Project description:Here we report high-resolution analyses of transcribing RNAPIII in either a wild-type (WT) background , a sen1-3 mutant or a Sen1 auxin-inducible degron (AID) strain in which Sen1 can be rapidly depleted upon addition of the auxin analogue Indole-3-acetic acid (IAA). Sen1 is a well-characterized transcription termination factor for RNAPII-dependent genes in budding yeast. Here we show that the presence of three point mutations in sen1-3 that abrogate the interaction of Sen1 with RNAPIII, as well as the depletion of Sen1 provoke global transcription termination defects at RNAPIII-dependent genes. These results indicate that Sen1 is also a transcription termination factor for RNAPIII transcription units.
Project description:Pervasive transcription is a widespread phenomenon leading to the production of a plethora of non-coding RNAs (ncRNAs) without apparent function. Pervasive transcription poses a risk that needs to be controlled to prevent the perturbation of gene expression. In yeast, the highly conserved helicase Sen1 restricts pervasive transcription by inducing termination of non-coding transcription. However, the mechanisms underlying the specific function of Sen1 at ncRNAs are poorly understood. Here we identify a motif in an intrinsically disordered region of Sen1 that mimics the phosphorylated carboxy terminal domain (CTD) of RNA polymerase II and characterize structurally its recognition by the CTD-interacting domain of Nrd1, an RNA-binding protein that binds specific sequences in ncRNAs. In addition, we show that Sen1-dependent termination strictly requires the recognition of the Ser5-phosphorylated form of the CTD by the N-terminal domain of Sen1. Furthermore, we find that the N-terminal and the C-terminal domains of Sen1 can mediate intra-molecular interactions. Our results shed light onto the network of protein-protein interactions that control termination of non-coding transcription by Sen1.
Project description: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).
Project description:Here we report high-resolution analyses of transcribing RNAPIII in either a wild-type (WT) background or a sen1-3 mutant in the G1 phase of the cell cycle. The mutations in Sen1-3 prevent the interaction of Sen1 with both RNAPIII and the replisome, raising the question whether the role of Sen1 in RNAPIII transcription termination could depend on the association of Sen1 with the replisome. Our data show that in the G1 phase of the cell cycle, where the replisome is not assembled, the sen1-3 mutant also exhibits transcription termination defects at RNAPIII-dependent genes, as in asynchronous cells. This result indicates that the role of Sen1 in termination at RNAPIII-dependent genes is independent on the association of Sen1 with the replisome.
Project description: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.
Project description:It is currently believed that termination by RNAPII occurs differently depending whether a transcript contains or lacks a polyadenylation signal (PAS). By screening for factors deficient for PAS-dependent termination in an in vivo reporter assay, we identified Sen1, a putative helicase mainly known for its role in PAS-independent termination of snoRNAs. We show for the first time that Sen1 regulates transcription termination at protein-encoding genes genome-wide. As well, we show that Sen1 suppresses cryptic transcription genome-wide, besides being required for termination of most snoRNAs. We provide evidence that Sen1 controls termination through its helicase activity and by effectively recruiting to chromatin, factors implicated in PAS-dependent (Rna14 and Rat1) or PAS-independent termination (Nrd1). Importantly, we demonstrate that the effect on transcription termination of Sen1 and Nrd1, although similar, differ quantitatively and qualitatively. Our results suggest that in yeast, termination by RNAPII at protein encoding-genes makes use of redundant pathways.
Project description:Pervasive transcription is a widespread phenomenon leading to the production of a plethora of non-coding RNAs (ncRNAs) without apparent function. Pervasive transcription poses a risk that needs to be controlled to prevent the perturbation of gene expression. In yeast, the highly conserved helicase Sen1 restricts pervasive transcription by inducing termination of non-coding transcription. However, the mechanisms underlying the specific function of Sen1 at ncRNAs are poorly understood. Here we identify a motif in an intrinsically disordered region of Sen1 that mimics the phosphorylated carboxy terminal domain (CTD) of RNA polymerase II and characterize structurally its recognition by the CTD-interacting domain of Nrd1, an RNA-binding protein that binds specific sequences in ncRNAs. In addition, we show that Sen1-dependent termination strictly requires the recognition of the Ser5-phosphorylated form of the CTD by the N-terminal domain of Sen1. Furthermore, we find that the N-terminal and the C-terminal domains of Sen1 can mediate intra-molecular interactions. Our results shed light onto the network of protein-protein interactions that control termination of non-coding transcription by Sen1.
Project description:Functional engagement of RNA polymerase II (Pol II) with eukaryotic chromosomes is a fundamental and highly regulated biological process. Here we present the first high-resolution map of Pol II occupancy across the entire yeast genome. We compared a wild-type strain with a strain bearing a substitution in the Sen1 helicase, which is a Pol II termination factor for non-coding RNA genes. The wildtype pattern of Pol II distribution provides unexpected insights into the mechanisms by which genes are repressed or silenced. Remarkably, a single amino acid substitution that compromises Sen1 function causes profound changes in Pol II distribution over both non-coding and protein-coding genes, establishing an important function of Sen1 in the regulation of transcription. Given the strong similarity of the yeast and human Sen1 proteins, our results suggest that progressive neurological disorders caused by substitutions in the human Sen1 homolog, Senataxin, may be due to misregulation of transcription. Keywords: transcription termination, attenuation, silencing, non-coding RNA, Pol II, ChIP-chip