The RNA exosome processes a wide variety of RNA and mediates RNA maturation, quality control and decay. In marked contrast to its high processivity in vivo, the purified exosome exhibits only weak activity on RNA substrates in vitro. Its activity is regulated by several auxiliary proteins, and protein complexes. In budding yeast, the activity of exosome is enhanced by the polyadenylation complex referred to as TRAMP. TRAMP oligoadenylates precursors and aberrant forms of RNAs to promote their trimming or complete degradation by exosomes. This chapter provides protocols for the purification of TRAMP and exosome complexes from yeast and the in vitro evaluation of exosome activation by the TRAMP complex. The protocols can be used for different purposes, such as the assessment of the role of individual subunits, protein domains or particular mutations in TRAMP-exosome RNA processing in vitro.

• Klíčová slova
• Air1, Air2, Degradation assay, Mtr4, Noncanonical poly(A) polymerase, Noncoding RNAs, Polyadenylation assay, RNA exosome, RNA quality control, Rrp6, TAP purification, TRAMP4, Trf4,
• MeSH
• buněčné jádro metabolismus   MeSH
• exozom metabolismus   MeSH
• exozómy metabolismus   MeSH
• polyadenylace fyziologie   MeSH
• RNA metabolismus   MeSH
• Saccharomyces cerevisiae - proteiny metabolismus   MeSH
• Saccharomyces cerevisiae metabolismus   MeSH
• serinové endopeptidasy metabolismus   MeSH
• stabilita RNA fyziologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• exozom MeSH
• RNA MeSH
• Saccharomyces cerevisiae - proteiny MeSH
• serinové endopeptidasy MeSH
• tunicate retinoic acid-inducible modular protease MeSH Prohlížeč

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 threat to proper gene expression that needs to be controlled. 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 structurally characterize 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 CTD recognition by the N-terminal domain of Sen1. We provide evidence that the Sen1-CTD interaction does not promote initial Sen1 recruitment, but rather enhances Sen1 capacity to induce the release of paused RNAPII from the DNA. Our results shed light on the network of protein-protein interactions that control termination of non-coding transcription by Sen1.

• Klíčová slova
• RNA polymerase II CTD, Sen1 helicase, non-coding transcription, pervasive transcription, transcription termination,
• MeSH
• DNA-helikasy chemie   metabolismus   MeSH
• fungální RNA metabolismus   MeSH
• konformace proteinů MeSH
• molekulární modely MeSH
• nekódující RNA metabolismus   MeSH
• proteinové domény MeSH
• proteiny vázající RNA chemie   metabolismus   MeSH
• regulace genové exprese u hub MeSH
• RNA-helikasy chemie   metabolismus   MeSH
• RNA-polymerasa II chemie   MeSH
• Saccharomyces cerevisiae - proteiny chemie   metabolismus   MeSH
• Saccharomyces cerevisiae genetika   metabolismus   MeSH
• terminace genetické transkripce MeSH
• vazba proteinů MeSH
• vazebná místa MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• DNA-helikasy MeSH
• fungální RNA MeSH
• nekódující RNA MeSH
• NRD1 protein, S cerevisiae MeSH Prohlížeč
• proteiny vázající RNA MeSH
• RNA-helikasy MeSH
• RNA-polymerasa II MeSH
• Saccharomyces cerevisiae - proteiny MeSH
• SEN1 protein, S cerevisiae MeSH Prohlížeč

Most eukaryotic RNAs are posttranscriptionally modified. The majority of modifications promote RNA maturation, others may regulate function and stability. The 3' terminal non-templated oligouridylation is a widespread modification affecting many cellular RNAs at some stage of their life cycle. It has diverse roles in RNA metabolism. The most prevalent is the regulation of stability and quality control. On the cellular and organismal level, it plays a critical role in a number of pathways, such as cell cycle regulation, cell death, development or viral infection. Defects in uridylation have been linked to several diseases. This review summarizes the current knowledge about the role of the 3' terminal oligo(U)-tailing in biology of various RNAs in eukaryotes and describes key factors involved in these pathways.This article is part of the theme issue '5' and 3' modifications controlling RNA degradation'.

• Klíčová slova
• RNA degradation, RNA modification, RNA processing, RNA surveillance, RNA uridylation, tutase,
• MeSH
• Eukaryota MeSH
• eukaryotické buňky fyziologie   MeSH
• lidé MeSH
• RNA metabolismus   MeSH
• úpravy 3' konce RNA * MeSH
• uridin metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• RNA MeSH
• uridin MeSH

The Nuclear Exosome Targeting (NEXT) complex is a key cofactor of the mammalian nuclear exosome in the removal of Promoter Upstream Transcripts (PROMPTs) and potentially aberrant forms of other noncoding RNAs, such as snRNAs. NEXT is composed of three subunits SKIV2L2, ZCCHC8 and RBM7. We have recently identified the NEXT complex in our screen for oligo(U) RNA-binding factors. Here, we demonstrate that NEXT displays preference for U-rich pyrimidine sequences and this RNA binding is mediated by the RNA recognition motif (RRM) of the RBM7 subunit. We solved the structure of RBM7 RRM and identified two phenylalanine residues that are critical for interaction with RNA. Furthermore, we showed that these residues are required for the NEXT interaction with snRNAs in vivo. Finally, we show that depletion of components of the NEXT complex alone or together with exosome nucleases resulted in the accumulation of mature as well as extended forms of snRNAs. Thus, our data suggest a new scenario in which the NEXT complex is involved in the surveillance of snRNAs and/or biogenesis of snRNPs.

• MeSH
• aminokyselinové motivy MeSH
• HEK293 buňky MeSH
• HeLa buňky MeSH
• lidé MeSH
• oligoribonukleotidy metabolismus   MeSH
• podjednotky proteinů chemie   metabolismus   MeSH
• proteiny vázající RNA analýza   chemie   metabolismus   MeSH
• RNA malá jaderná chemie   metabolismus   MeSH
• sekvence nukleotidů MeSH
• uracilnukleotidy metabolismus   MeSH
• vazba proteinů MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• oligo(U) MeSH Prohlížeč
• oligoribonukleotidy MeSH
• podjednotky proteinů MeSH
• proteiny vázající RNA MeSH
• RBM7 protein, human MeSH Prohlížeč
• RNA malá jaderná MeSH
• uracilnukleotidy MeSH

The Nrd1-Nab3-Sen1 (NNS) complex is essential for controlling pervasive transcription and generating sn/snoRNAs in S. cerevisiae. The NNS complex terminates transcription of noncoding RNA genes and promotes exosome-dependent processing/degradation of the released transcripts. The Trf4-Air2-Mtr4 (TRAMP) complex polyadenylates NNS target RNAs and favors their degradation. NNS-dependent termination and degradation are coupled, but the mechanism underlying this coupling remains enigmatic. Here we provide structural and functional evidence demonstrating that the same domain of Nrd1p interacts with RNA polymerase II and Trf4p in a mutually exclusive manner, thus defining two alternative forms of the NNS complex, one involved in termination and the other in degradation. We show that the Nrd1-Trf4 interaction is required for optimal exosome activity in vivo and for the stimulation of polyadenylation of NNS targets by TRAMP in vitro. We propose that transcription termination and RNA degradation are coordinated by switching between two alternative partners of the NNS complex.

• MeSH
• DNA-dependentní DNA-polymerasy chemie   metabolismus   MeSH
• exozómy metabolismus   MeSH
• fungální RNA metabolismus   MeSH
• konformace nukleové kyseliny MeSH
• magnetická rezonanční spektroskopie MeSH
• molekulární modely MeSH
• nekódující RNA metabolismus   MeSH
• polyadenylace MeSH
• proteiny vázající RNA chemie   metabolismus   MeSH
• RNA-polymerasa II metabolismus   MeSH
• Saccharomyces cerevisiae - proteiny chemie   metabolismus   MeSH
• Saccharomyces cerevisiae genetika   MeSH
• stabilita RNA MeSH
• terminace genetické transkripce * MeSH
• vazebná místa MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• DNA-dependentní DNA-polymerasy MeSH
• fungální RNA MeSH
• nekódující RNA MeSH
• NRD1 protein, S cerevisiae MeSH Prohlížeč
• PAP2 protein, S cerevisiae MeSH Prohlížeč
• proteiny vázající RNA MeSH
• RNA-polymerasa II MeSH
• Saccharomyces cerevisiae - proteiny MeSH

In Saccharomyces cerevisiae, the Nrd1-dependent termination and processing pathways play an important role in surveillance and processing of non-coding ribonucleic acids (RNAs). The termination and subsequent processing is dependent on the Nrd1 complex consisting of two RNA-binding proteins Nrd1 and Nab3 and Sen1 helicase. It is established that Nrd1 and Nab3 cooperatively recognize specific termination elements within nascent RNA, GUA[A/G] and UCUU[G], respectively. Interestingly, some transcripts do not require GUA[A/G] motif for transcription termination in vivo and binding in vitro, suggesting the existence of alternative Nrd1-binding motifs. Here we studied the structure and RNA-binding properties of Nrd1 using nuclear magnetic resonance (NMR), fluorescence anisotropy and phenotypic analyses in vivo. We determined the solution structure of a two-domain RNA-binding fragment of Nrd1, formed by an RNA-recognition motif and helix-loop bundle. NMR and fluorescence data show that not only GUA[A/G] but also several other G-rich and AU-rich motifs are able to bind Nrd1 with affinity in a low micromolar range. The broad substrate specificity is achieved by adaptable interaction surfaces of the RNA-recognition motif and helix-loop bundle domains that sandwich the RNA substrates. Our findings have implication for the role of Nrd1 in termination and processing of many non-coding RNAs arising from bidirectional pervasive transcription.

• MeSH
• dimerizace MeSH
• molekulární modely MeSH
• mutace MeSH
• proteiny vázající RNA chemie   genetika   metabolismus   MeSH
• RNA chemie   metabolismus   MeSH
• Saccharomyces cerevisiae - proteiny chemie   genetika   metabolismus   MeSH
• terciární struktura proteinů MeSH
• vazba proteinů MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• NRD1 protein, S cerevisiae MeSH Prohlížeč
• proteiny vázající RNA MeSH
• RNA MeSH
• Saccharomyces cerevisiae - proteiny MeSH

Recruitment of appropriate RNA processing factors to the site of transcription is controlled by post-translational modifications of the C-terminal domain (CTD) of RNA polymerase II (RNAP II). Here, we report the solution structure of the Ser5 phosphorylated (pSer5) CTD bound to Nrd1. The structure reveals a direct recognition of pSer5 by Nrd1 that requires the cis conformation of the upstream pSer5-Pro6 peptidyl-prolyl bond of the CTD. Mutations at the complex interface diminish binding affinity and impair processing or degradation of noncoding RNAs. These findings underpin the interplay between covalent and noncovalent changes in the CTD structure that constitute the CTD code.

• MeSH
• fosforylace MeSH
• molekulární modely MeSH
• nekódující RNA metabolismus   MeSH
• prolin metabolismus   MeSH
• proteiny vázající RNA chemie   metabolismus   MeSH
• RNA-polymerasa II metabolismus   MeSH
• Saccharomyces cerevisiae - proteiny chemie   metabolismus   MeSH
• Saccharomyces cerevisiae cytologie   enzymologie   genetika   metabolismus   MeSH
• serin metabolismus   MeSH
• terciární struktura proteinů MeSH
• vazba proteinů MeSH
• viabilita buněk MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• nekódující RNA MeSH
• NRD1 protein, S cerevisiae MeSH Prohlížeč
• prolin MeSH
• proteiny vázající RNA MeSH
• RNA-polymerasa II MeSH
• Saccharomyces cerevisiae - proteiny MeSH
• serin MeSH

Trf4/5p-Air1/2p-Mtr4p polyadenylation complex (TRAMP) is an essential component of nuclear RNA surveillance in yeast. It recognizes a variety of nuclear transcripts produced by all three RNA polymerases, adds short poly(A) tails to aberrant or unstable RNAs and activates the exosome for their degradation. Despite the advances in understanding the structural features of the isolated complex subunits or their fragments, the details of complex assembly, RNA recognition and exosome activation remain poorly understood. Here we provide the first understanding of the RNA binding mode of the complex. We show that Air2p is an RNA-binding subunit of TRAMP. We identify the zinc knuckles (ZnK) 2, 3 and 4 as the RNA-binding domains, and reveal the essentiality of ZnK4 for TRAMP4 polyadenylation activity. Furthermore, we identify Air2p as the key component of TRAMP4 assembly providing bridging between Mtr4p and Trf4p. The former is bound via the N-terminus of Air2p, while the latter is bound via ZnK5, the linker between ZnK4 and 5 and the C-terminus of the protein. Finally, we uncover the RNA binding part of the Mtr4p arch, the KOW domain, as the essential component for TRAMP-mediated exosome activation.

• MeSH
• adaptorové proteiny signální transdukční chemie   metabolismus   MeSH
• DEAD-box RNA-helikasy chemie   metabolismus   MeSH
• DNA-dependentní DNA-polymerasy chemie   metabolismus   MeSH
• interakční proteinové domény a motivy MeSH
• podjednotky proteinů chemie   metabolismus   MeSH
• proteiny vázající RNA chemie   metabolismus   MeSH
• ribonukleasy metabolismus   MeSH
• Saccharomyces cerevisiae - proteiny chemie   metabolismus   MeSH
• terciární struktura proteinů MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• adaptorové proteiny signální transdukční MeSH
• Air2 protein, S cerevisiae MeSH Prohlížeč
• DEAD-box RNA-helikasy MeSH
• DNA-dependentní DNA-polymerasy MeSH
• MTR4 protein, S cerevisiae MeSH Prohlížeč
• PAP2 protein, S cerevisiae MeSH Prohlížeč
• podjednotky proteinů MeSH
• proteiny vázající RNA MeSH
• ribonukleasy MeSH
• Saccharomyces cerevisiae - proteiny MeSH

Non-coding RNA polymerase II transcripts are processed by the poly(A)-independent termination pathway that requires the Nrd1 complex. The Nrd1 complex includes two RNA-binding proteins, the nuclear polyadenylated RNA-binding (Nab) 3 and the nuclear pre-mRNA down-regulation (Nrd) 1 that bind their specific termination elements. Here we report the solution structure of the RNA-recognition motif (RRM) of Nab3 in complex with a UCUU oligonucleotide, representing the Nab3 termination element. The structure shows that the first three nucleotides of UCUU are accommodated on the β-sheet surface of Nab3 RRM, but reveals a sequence-specific recognition only for the central cytidine and uridine. The specific contacts we identified are important for binding affinity in vitro as well as for yeast viability. Furthermore, we show that both RNA-binding motifs of Nab3 and Nrd1 alone bind their termination elements with a weak affinity. Interestingly, when Nab3 and Nrd1 form a heterodimer, the affinity to RNA is significantly increased due to the cooperative binding. These findings are in accordance with the model of their function in the poly(A) independent termination, in which binding to the combined and/or repetitive termination elements elicits efficient termination.

• MeSH
• genetická transkripce * MeSH
• jaderné proteiny chemie   genetika   metabolismus   MeSH
• konformace proteinů MeSH
• magnetická rezonanční spektroskopie MeSH
• multimerizace proteinu MeSH
• oligonukleotidy chemie   metabolismus   MeSH
• proteiny vázající RNA chemie   genetika   metabolismus   MeSH
• roztoky MeSH
• Saccharomyces cerevisiae - proteiny chemie   genetika   metabolismus   MeSH
• Saccharomyces cerevisiae genetika   MeSH
• sekvence nukleotidů MeSH
• vazba proteinů MeSH
• vazebná místa MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• jaderné proteiny MeSH
• NAB3 protein, S cerevisiae MeSH Prohlížeč
• NRD1 protein, S cerevisiae MeSH Prohlížeč
• oligonukleotidy MeSH
• proteiny vázající RNA MeSH
• roztoky MeSH
• Saccharomyces cerevisiae - proteiny MeSH