1
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An W, Yan Y, Ye K. High resolution landscape of ribosomal RNA processing and surveillance. Nucleic Acids Res 2024; 52:10630-10644. [PMID: 38994562 PMCID: PMC11417381 DOI: 10.1093/nar/gkae606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 06/21/2024] [Accepted: 06/28/2024] [Indexed: 07/13/2024] Open
Abstract
Ribosomal RNAs are processed in a complex pathway. We profiled rRNA processing intermediates in yeast at single-molecule and single-nucleotide levels with circularization, targeted amplification and deep sequencing (CircTA-seq), gaining significant mechanistic insights into rRNA processing and surveillance. The long form of the 5' end of 5.8S rRNA is converted to the short form and represents an intermediate of a unified processing pathway. The initial 3' end processing of 5.8S rRNA involves trimming by Rex1 and Rex2 and Trf4-mediated polyadenylation. The 3' end of 25S rRNA is formed by sequential digestion by four Rex proteins. Intermediates with an extended A1 site are generated during 5' degradation of aberrant 18S rRNA precursors. We determined precise polyadenylation profiles for pre-rRNAs and show that the degradation efficiency of polyadenylated 20S pre-rRNA critically depends on poly(A) lengths and degradation intermediates released from the exosome are often extensively re-polyadenylated.
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MESH Headings
- RNA Processing, Post-Transcriptional
- Saccharomyces cerevisiae/genetics
- Saccharomyces cerevisiae/metabolism
- RNA, Ribosomal/metabolism
- RNA, Ribosomal/genetics
- RNA, Ribosomal/chemistry
- RNA, Ribosomal, 5.8S/genetics
- RNA, Ribosomal, 5.8S/metabolism
- Saccharomyces cerevisiae Proteins/metabolism
- Saccharomyces cerevisiae Proteins/genetics
- RNA Precursors/metabolism
- RNA Precursors/genetics
- RNA, Ribosomal, 18S/metabolism
- RNA, Ribosomal, 18S/genetics
- Polyadenylation
- RNA, Fungal/metabolism
- RNA, Fungal/chemistry
- RNA, Fungal/genetics
- Exosome Multienzyme Ribonuclease Complex/metabolism
- Exosome Multienzyme Ribonuclease Complex/genetics
- High-Throughput Nucleotide Sequencing
- RNA Stability
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Affiliation(s)
- Weidong An
- Key Laboratory of RNA Science and Engineering, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Yunxiao Yan
- Key Laboratory of RNA Science and Engineering, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Keqiong Ye
- Key Laboratory of RNA Science and Engineering, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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2
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Denson JM, Zhang N, Ball D, Thompson K, Johnson SJ, D'Arcy S. TRAMP assembly alters the conformation and RNA binding of Mtr4 and Trf4-Air2. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.25.605035. [PMID: 39211223 PMCID: PMC11360972 DOI: 10.1101/2024.07.25.605035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
The TRAMP complex contains two enzymatic activities essential for RNA processing upstream of the nuclear exosome. Within TRAMP, RNA is 3' polyadenylated by a sub-complex of Trf4/5 and Air1/2 and unwound 3' to 5' by Mtr4, a DExH helicase. The molecular mechanisms of TRAMP assembly and RNA shuffling between the two TRAMP catalytic sites are poorly understood. Here, we report solution hydrogen-deuterium exchange data with thermodynamic and functional assays to uncover these mechanisms for yeast TRAMP with Trf4 and Air2 homologs. We show that TRAMP assembly constrains RNA-recognition motifs that are peripheral to catalytic sites. These include the Mtr4 Arch and Air2 zinc knuckles 1, 2, and 3. While the Air2 Arch-interacting motif likely constrains the Mtr4 Arch via transient interactions, these do not fully account for the importance of the Mtr4 Arch in TRAMP assembly. We further show that tRNA binding by single active-site subunits, Mtr4 and Trf4-Air2, differs from the double active-site TRAMP. TRAMP has reduced tRNA binding on the Mtr4 Fist and RecA2 domains, offset by increased tRNA binding on Air2 zinc knuckles 2 and 3. Competition between these RNA-binding sites may drive tRNA transfer between TRAMP subunits. We identify dynamic changes upon TRAMP assembly and RNA-recognition motifs that transfer RNA between TRAMP catalytic sites.
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3
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Tomecki R, Drazkowska K, Kobylecki K, Tudek A. SKI complex: A multifaceted cytoplasmic RNA exosome cofactor in mRNA metabolism with links to disease, developmental processes, and antiviral responses. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023; 14:e1795. [PMID: 37384835 DOI: 10.1002/wrna.1795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 04/26/2023] [Accepted: 05/01/2023] [Indexed: 07/01/2023]
Abstract
RNA stability and quality control are integral parts of gene expression regulation. A key factor shaping eukaryotic transcriptomes, mainly via 3'-5' exoribonucleolytic trimming or degradation of diverse transcripts in nuclear and cytoplasmic compartments, is the RNA exosome. Precise exosome targeting to various RNA molecules requires strict collaboration with specialized auxiliary factors, which facilitate interactions with its substrates. The predominant class of cytoplasmic RNA targeted by the exosome are protein-coding transcripts, which are carefully scrutinized for errors during translation. Normal, functional mRNAs are turned over following protein synthesis by the exosome or by Xrn1 5'-3'-exonuclease, acting in concert with Dcp1/2 decapping complex. In turn, aberrant transcripts are eliminated by dedicated surveillance pathways, triggered whenever ribosome translocation is impaired. Cytoplasmic 3'-5' mRNA decay and surveillance are dependent on the tight cooperation between the exosome and its evolutionary conserved co-factor-the SKI (superkiller) complex (SKIc). Here, we summarize recent findings from structural, biochemical, and functional studies of SKIc roles in controlling cytoplasmic RNA metabolism, including links to various cellular processes. Mechanism of SKIc action is illuminated by presentation of its spatial structure and details of its interactions with exosome and ribosome. Furthermore, contribution of SKIc and exosome to various mRNA decay pathways, usually converging on recycling of ribosomal subunits, is delineated. A crucial physiological role of SKIc is emphasized by describing association between its dysfunction and devastating human disease-a trichohepatoenteric syndrome (THES). Eventually, we discuss SKIc functions in the regulation of antiviral defense systems, cell signaling and developmental transitions, emerging from interdisciplinary investigations. This article is categorized under: RNA Turnover and Surveillance > Turnover/Surveillance Mechanisms RNA Turnover and Surveillance > Regulation of RNA Stability RNA Interactions with Proteins and Other Molecules > RNA-Protein Complexes.
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Affiliation(s)
- Rafal Tomecki
- Laboratory of RNA Processing and Decay, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Karolina Drazkowska
- Laboratory of Epitranscriptomics, Department of Environmental Microbiology and Biotechnology, Institute of Microbiology, Faculty of Biology, Biological and Chemical Research Centre, University of Warsaw, Warsaw, Poland
| | - Kamil Kobylecki
- Laboratory of RNA Processing and Decay, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Agnieszka Tudek
- Laboratory of RNA Processing and Decay, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
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4
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Li B, Zeis P, Zhang Y, Alekseenko A, Fürst E, Sanchez YP, Lin G, Tekkedil MM, Piazza I, Steinmetz LM, Pelechano V. Differential regulation of mRNA stability modulates transcriptional memory and facilitates environmental adaptation. Nat Commun 2023; 14:910. [PMID: 36801853 PMCID: PMC9936472 DOI: 10.1038/s41467-023-36586-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 02/06/2023] [Indexed: 02/19/2023] Open
Abstract
Transcriptional memory, by which cells respond faster to repeated stimuli, is key for cellular adaptation and organism survival. Chromatin organization has been shown to play a role in the faster response of primed cells. However, the contribution of post-transcriptional regulation is not yet explored. Here we perform a genome-wide screen to identify novel factors modulating transcriptional memory in S. cerevisiae in response to galactose. We find that depletion of the nuclear RNA exosome increases GAL1 expression in primed cells. Our work shows that gene-specific differences in intrinsic nuclear surveillance factor association can enhance both gene induction and repression in primed cells. Finally, we show that primed cells present altered levels of RNA degradation machinery and that both nuclear and cytoplasmic mRNA decay modulate transcriptional memory. Our results demonstrate that mRNA post-transcriptional regulation, and not only transcription regulation, should be considered when investigating gene expression memory.
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Affiliation(s)
- Bingnan Li
- Department of Diagnostics, Medical Integration and Practice Center, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, 250012, China.,SciLifeLab, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Solna, Sweden
| | - Patrice Zeis
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Heidelberg, Germany.,Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland
| | - Yujie Zhang
- SciLifeLab, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Solna, Sweden
| | - Alisa Alekseenko
- SciLifeLab, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Solna, Sweden
| | - Eliska Fürst
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC Berlin), Berlin, Germany
| | - Yerma Pareja Sanchez
- SciLifeLab, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Solna, Sweden
| | - Gen Lin
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Heidelberg, Germany.,AbbVie Pte Ltd, Singapore, Singapore
| | - Manu M Tekkedil
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Heidelberg, Germany
| | - Ilaria Piazza
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC Berlin), Berlin, Germany
| | - Lars M Steinmetz
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Heidelberg, Germany.,Stanford Genome Technology Center, Stanford University, Palo Alto, CA, USA.,Department of Genetics, School of Medicine, Stanford University, Stanford, CA, USA
| | - Vicent Pelechano
- SciLifeLab, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Solna, Sweden.
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5
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Webster SF, Ghalei H. Maturation of small nucleolar RNAs: from production to function. RNA Biol 2023; 20:715-736. [PMID: 37796118 PMCID: PMC10557570 DOI: 10.1080/15476286.2023.2254540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/28/2023] [Indexed: 10/06/2023] Open
Abstract
Small Nucleolar RNAs (snoRNAs) are an abundant group of non-coding RNAs with well-defined roles in ribosomal RNA processing, folding and chemical modification. Besides their classic roles in ribosome biogenesis, snoRNAs are also implicated in several other cellular activities including regulation of splicing, transcription, RNA editing, cellular trafficking, and miRNA-like functions. Mature snoRNAs must undergo a series of processing steps tightly regulated by transiently associating factors and coordinated with other cellular processes including transcription and splicing. In addition to their mature forms, snoRNAs can contribute to gene expression regulation through their derivatives and degradation products. Here, we review the current knowledge on mechanisms of snoRNA maturation, including the different pathways of processing, and the regulatory mechanisms that control snoRNA levels and complex assembly. We also discuss the significance of studying snoRNA maturation, highlight the gaps in the current knowledge and suggest directions for future research in this area.
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Affiliation(s)
- Sarah F. Webster
- Biochemistry, Cell, and Developmental Biology Graduate Program, Emory University, Atlanta, Georgia, USA
- Department of Biochemistry, Emory University, Atlanta, Georgia, USA
| | - Homa Ghalei
- Department of Biochemistry, Emory University, Atlanta, Georgia, USA
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6
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Alles J, Legnini I, Pacelli M, Rajewsky N. Rapid nuclear deadenylation of mammalian messenger RNA. iScience 2022; 26:105878. [PMID: 36691625 PMCID: PMC9860345 DOI: 10.1016/j.isci.2022.105878] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 06/13/2022] [Accepted: 12/22/2022] [Indexed: 12/29/2022] Open
Abstract
Poly(A) tails protect RNAs from degradation and their deadenylation rates determine RNA stability. Although poly(A) tails are generated in the nucleus, deadenylation of tails has mostly been investigated within the cytoplasm. Here, we combined long-read sequencing with metabolic labeling, splicing inhibition and cell fractionation experiments to quantify, separately, the genesis and trimming of nuclear and cytoplasmic tails in vitro and in vivo. We present evidence for genome-wide, nuclear synthesis of tails longer than 200 nt, which are rapidly shortened after transcription. Our data suggests that rapid deadenylation is a nuclear process, and that different classes of transcripts and even transcript isoforms have distinct nuclear tail lengths. For example, many long-noncoding RNAs retain long poly(A) tails. Modeling deadenylation dynamics predicts nuclear deadenylation about 10 times faster than cytoplasmic deadenylation. In summary, our data suggests that nuclear deadenylation might be a key mechanism for regulating mRNA stability, abundance, and subcellular localization.
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Affiliation(s)
- Jonathan Alles
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Laboratory for Systems Biology of Gene Regulatory Elements, Hannoversche Str. 28, 10115 Berlin, Germany,Humboldt-Universität zu Berlin, Institute of Biology, Unter den Linden 6, 10099 Berlin, Germany
| | - Ivano Legnini
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Laboratory for Systems Biology of Gene Regulatory Elements, Hannoversche Str. 28, 10115 Berlin, Germany
| | - Maddalena Pacelli
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Laboratory for Systems Biology of Gene Regulatory Elements, Hannoversche Str. 28, 10115 Berlin, Germany
| | - Nikolaus Rajewsky
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Laboratory for Systems Biology of Gene Regulatory Elements, Hannoversche Str. 28, 10115 Berlin, Germany,Humboldt-Universität zu Berlin, Institute of Biology, Unter den Linden 6, 10099 Berlin, Germany,Corresponding author
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7
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Brown RE, Su XA, Fair S, Wu K, Verra L, Jong R, Andrykovich K, Freudenreich CH. The RNA export and RNA decay complexes THO and TRAMP prevent transcription-replication conflicts, DNA breaks, and CAG repeat contractions. PLoS Biol 2022; 20:e3001940. [PMID: 36574440 PMCID: PMC9829180 DOI: 10.1371/journal.pbio.3001940] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 01/09/2023] [Accepted: 12/01/2022] [Indexed: 12/28/2022] Open
Abstract
Expansion of structure-forming CAG/CTG repetitive sequences is the cause of several neurodegenerative disorders and deletion of repeats is a potential therapeutic strategy. Transcription-associated mechanisms are known to cause CAG repeat instability. In this study, we discovered that Thp2, an RNA export factor and member of the THO (suppressors of transcriptional defects of hpr1Δ by overexpression) complex, and Trf4, a key component of the TRAMP (Trf4/5-Air1/2-Mtr4 polyadenylation) complex involved in nuclear RNA polyadenylation and degradation, are necessary to prevent CAG fragility and repeat contractions in a Saccharomyces cerevisiae model system. Depletion of both Thp2 and Trf4 proteins causes a highly synergistic increase in CAG repeat fragility, indicating a complementary role of the THO and TRAMP complexes in preventing genome instability. Loss of either Thp2 or Trf4 causes an increase in RNA polymerase stalling at the CAG repeats and other genomic loci, as well as genome-wide transcription-replication conflicts (TRCs), implicating TRCs as a cause of CAG fragility and instability in their absence. Analysis of the effect of RNase H1 overexpression on CAG fragility, RNAPII stalling, and TRCs suggests that RNAPII stalling with associated R-loops are the main cause of CAG fragility in the thp2Δ mutants. In contrast, CAG fragility and TRCs in the trf4Δ mutant can be compensated for by RPA overexpression, suggesting that excess unprocessed RNA in TRAMP4 mutants leads to reduced RPA availability and high levels of TRCs. Our results show the importance of RNA surveillance pathways in preventing RNAPII stalling, TRCs, and DNA breaks, and show that RNA export and RNA decay factors work collaboratively to maintain genome stability.
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Affiliation(s)
- Rebecca E. Brown
- Program in Genetics, Tufts University School of Graduate Biomedical Sciences, Boston, Massachusetts, United States of America
| | - Xiaofeng A. Su
- Department of Biology, Tufts University, Medford, Massachusetts, United States of America
- David H. Koch Institute for Integrative Cancer Research, Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Stacey Fair
- Department of Biology, Tufts University, Medford, Massachusetts, United States of America
| | - Katherine Wu
- Department of Biology, Tufts University, Medford, Massachusetts, United States of America
| | - Lauren Verra
- Department of Biology, Tufts University, Medford, Massachusetts, United States of America
| | - Robyn Jong
- Department of Biology, Tufts University, Medford, Massachusetts, United States of America
| | - Kristin Andrykovich
- Department of Biology, Tufts University, Medford, Massachusetts, United States of America
| | - Catherine H. Freudenreich
- Program in Genetics, Tufts University School of Graduate Biomedical Sciences, Boston, Massachusetts, United States of America
- Department of Biology, Tufts University, Medford, Massachusetts, United States of America
- * E-mail:
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8
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MTR4 adaptor PICT1 functions in two distinct steps during pre-rRNA processing. Biochem Biophys Res Commun 2022; 637:203-209. [DOI: 10.1016/j.bbrc.2022.11.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 11/08/2022] [Indexed: 11/10/2022]
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9
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Novačić A, Menéndez D, Ljubas J, Barbarić S, Stutz F, Soudet J, Stuparević I. Antisense non-coding transcription represses the PHO5 model gene at the level of promoter chromatin structure. PLoS Genet 2022; 18:e1010432. [PMID: 36215302 PMCID: PMC9584416 DOI: 10.1371/journal.pgen.1010432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 10/20/2022] [Accepted: 09/15/2022] [Indexed: 11/09/2022] Open
Abstract
Pervasive transcription of eukaryotic genomes generates non-coding transcripts with regulatory potential. We examined the effects of non-coding antisense transcription on the regulation of expression of the yeast PHO5 gene, a paradigmatic case for gene regulation through promoter chromatin remodeling. A negative role for antisense transcription at the PHO5 gene locus was demonstrated by leveraging the level of overlapping antisense transcription through specific mutant backgrounds, expression from a strong promoter in cis, and use of the CRISPRi system. Furthermore, we showed that enhanced elongation of PHO5 antisense leads to a more repressive chromatin conformation at the PHO5 gene promoter, which is more slowly remodeled upon gene induction. The negative effect of antisense transcription on PHO5 gene transcription is mitigated upon inactivation of the histone deacetylase Rpd3, showing that PHO5 antisense RNA acts via histone deacetylation. This regulatory pathway leads to Rpd3-dependent decreased recruitment of the RSC chromatin remodeling complex to the PHO5 gene promoter upon induction of antisense transcription. Overall, the data in this work reveal an additional level in the complex regulatory mechanism of PHO5 gene expression by showing antisense transcription-mediated repression at the level of promoter chromatin structure remodeling.
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Affiliation(s)
- Ana Novačić
- Laboratory of Biochemistry, Department of Chemistry and Biochemistry, Faculty of Food Technology and Biotechnology, University of Zagreb, Zagreb, Croatia
| | - Dario Menéndez
- Department of Cell Biology, University of Geneva, Geneva, Switzerland
| | - Jurica Ljubas
- Laboratory of Biochemistry, Department of Chemistry and Biochemistry, Faculty of Food Technology and Biotechnology, University of Zagreb, Zagreb, Croatia
| | - Slobodan Barbarić
- Laboratory of Biochemistry, Department of Chemistry and Biochemistry, Faculty of Food Technology and Biotechnology, University of Zagreb, Zagreb, Croatia
| | - Françoise Stutz
- Department of Cell Biology, University of Geneva, Geneva, Switzerland
| | - Julien Soudet
- Department of Cell Biology, University of Geneva, Geneva, Switzerland
- * E-mail: (J.S.); (I.S.)
| | - Igor Stuparević
- Laboratory of Biochemistry, Department of Chemistry and Biochemistry, Faculty of Food Technology and Biotechnology, University of Zagreb, Zagreb, Croatia
- * E-mail: (J.S.); (I.S.)
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10
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Fujiwara N, Shigemoto M, Hirayama M, Fujita KI, Seno S, Matsuda H, Nagahama M, Masuda S. MPP6 stimulates both RRP6 and DIS3 to degrade a specified subset of MTR4-sensitive substrates in the human nucleus. Nucleic Acids Res 2022; 50:8779-8806. [PMID: 35902094 PMCID: PMC9410898 DOI: 10.1093/nar/gkac559] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 06/10/2022] [Accepted: 07/20/2022] [Indexed: 11/13/2022] Open
Abstract
Recent in vitro reconstitution analyses have proven that the physical interaction between the exosome core and MTR4 helicase, which promotes the exosome activity, is maintained by either MPP6 or RRP6. However, knowledge regarding the function of MPP6 with respect to in vivo exosome activity remains scarce. Here, we demonstrate a facilitative function of MPP6 that composes a specific part of MTR4-dependent substrate decay by the human exosome. Using RNA polymerase II-transcribed poly(A)+ substrate accumulation as an indicator of a perturbed exosome, we found functional redundancy between RRP6 and MPP6 in the decay of these poly(A)+ transcripts. MTR4 binding to the exosome core via MPP6 was essential for MPP6 to exert its redundancy with RRP6. However, at least for the decay of our identified exosome substrates, MTR4 recruitment by MPP6 was not functionally equivalent to recruitment by RRP6. Genome-wide classification of substrates based on their sensitivity to each exosome component revealed that MPP6 deals with a specific range of substrates and highlights the importance of MTR4 for their decay. Considering recent findings of competitive binding to the exosome between auxiliary complexes, our results suggest that the MPP6-incorporated MTR4-exosome complex is one of the multiple alternative complexes rather than the prevailing one.
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Affiliation(s)
- Naoko Fujiwara
- Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto 606-8502, Japan
| | - Maki Shigemoto
- Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto 606-8502, Japan
| | - Mizuki Hirayama
- Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto 606-8502, Japan
| | - Ken-Ichi Fujita
- Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto 606-8502, Japan.,Division of Gene Expression Mechanism, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Aichi 470-1192, Japan
| | - Shigeto Seno
- Graduate School of Information Science and Technology, Osaka University, Suita, Osaka 565-0871, Japan
| | - Hideo Matsuda
- Graduate School of Information Science and Technology, Osaka University, Suita, Osaka 565-0871, Japan
| | - Masami Nagahama
- Laboratory of Molecular and Cellular Biochemistry, Meiji Pharmaceutical University, Kiyose, Tokyo 204-8588, Japan
| | - Seiji Masuda
- Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto 606-8502, Japan.,Department of Food Science and Nutrition, Faculty of Agriculture Kindai University, Nara, Nara 631-8505, Japan.,Agricultural Technology and Innovation Research Institute, Kindai University, Nara, Nara 631-8505, Japan.,Antiaging center, Kindai University, Higashiosaka, Osaka 577-8502, Japan
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11
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Villa T, Porrua O. Pervasive transcription: a controlled risk. FEBS J 2022. [PMID: 35587776 DOI: 10.1111/febs.16530] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 04/26/2022] [Accepted: 05/17/2022] [Indexed: 11/30/2022]
Abstract
Transcriptome-wide interrogation of eukaryotic genomes has unveiled the pervasive nature of RNA polymerase II transcription. Virtually, any DNA region with an accessible chromatin structure can be transcribed, resulting in a mass production of noncoding RNAs (ncRNAs) with the potential of interfering with gene expression programs. Budding yeast has proved to be a powerful model organism to understand the mechanisms at play to control pervasive transcription and overcome the risks of hazardous disruption of cellular functions. In this review, we focus on the actors and strategies yeasts employ to govern ncRNA production, and we discuss recent findings highlighting the dangers of losing control over pervasive transcription.
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Affiliation(s)
- Tommaso Villa
- Institut Jacques Monod CNRS, Université de Paris Cité France
| | - Odil Porrua
- Institut Jacques Monod CNRS, Université de Paris Cité France
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12
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Lange H, Gagliardi D. Catalytic activities, molecular connections, and biological functions of plant RNA exosome complexes. THE PLANT CELL 2022; 34:967-988. [PMID: 34954803 PMCID: PMC8894942 DOI: 10.1093/plcell/koab310] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 12/16/2021] [Indexed: 05/08/2023]
Abstract
RNA exosome complexes provide the main 3'-5'-exoribonuclease activities in eukaryotic cells and contribute to the maturation and degradation of virtually all types of RNA. RNA exosomes consist of a conserved core complex that associates with exoribonucleases and with multimeric cofactors that recruit the enzyme to its RNA targets. Despite an overall high level of structural and functional conservation, the enzymatic activities and compositions of exosome complexes and their cofactor modules differ among eukaryotes. This review highlights unique features of plant exosome complexes, such as the phosphorolytic activity of the core complex, and discusses the exosome cofactors that operate in plants and are dedicated to the maturation of ribosomal RNA, the elimination of spurious, misprocessed, and superfluous transcripts, or the removal of mRNAs cleaved by the RNA-induced silencing complex and other mRNAs prone to undergo silencing.
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Affiliation(s)
- Heike Lange
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, Strasbourg, France
- Author for correspondence:
| | - Dominique Gagliardi
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, Strasbourg, France
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13
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Mitterer V, Pertschy B. RNA folding and functions of RNA helicases in ribosome biogenesis. RNA Biol 2022; 19:781-810. [PMID: 35678541 PMCID: PMC9196750 DOI: 10.1080/15476286.2022.2079890] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 05/16/2022] [Indexed: 11/13/2022] Open
Abstract
Eukaryotic ribosome biogenesis involves the synthesis of ribosomal RNA (rRNA) and its stepwise folding into the unique structure present in mature ribosomes. rRNA folding starts already co-transcriptionally in the nucleolus and continues when pre-ribosomal particles further maturate in the nucleolus and upon their transit to the nucleoplasm and cytoplasm. While the approximate order of folding of rRNA subdomains is known, especially from cryo-EM structures of pre-ribosomal particles, the actual mechanisms of rRNA folding are less well understood. Both small nucleolar RNAs (snoRNAs) and proteins have been implicated in rRNA folding. snoRNAs hybridize to precursor rRNAs (pre-rRNAs) and thereby prevent premature folding of the respective rRNA elements. Ribosomal proteins (r-proteins) and ribosome assembly factors might have a similar function by binding to rRNA elements and preventing their premature folding. Besides that, a small group of ribosome assembly factors are thought to play a more active role in rRNA folding. In particular, multiple RNA helicases participate in individual ribosome assembly steps, where they are believed to coordinate RNA folding/unfolding events or the release of proteins from the rRNA. In this review, we summarize the current knowledge on mechanisms of RNA folding and on the specific function of the individual RNA helicases involved. As the yeast Saccharomyces cerevisiae is the organism in which ribosome biogenesis and the role of RNA helicases in this process is best studied, we focused our review on insights from this model organism, but also make comparisons to other organisms where applicable.
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Affiliation(s)
- Valentin Mitterer
- Biochemistry Center, Heidelberg University, Im Neuenheimer Feld 328, Heidelberg, Germany
- BioTechMed-Graz, Graz, Austria
| | - Brigitte Pertschy
- BioTechMed-Graz, Graz, Austria
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, Graz, Austria
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14
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Yim MK, Denson JM, Gold MD, Johnson SJ. Purification and characterization of Mtr4 and TRAMP from S. cerevisiae. Methods Enzymol 2022; 673:425-451. [DOI: 10.1016/bs.mie.2022.03.042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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15
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Global view on the metabolism of RNA poly(A) tails in yeast Saccharomyces cerevisiae. Nat Commun 2021; 12:4951. [PMID: 34400637 PMCID: PMC8367983 DOI: 10.1038/s41467-021-25251-w] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 07/29/2021] [Indexed: 02/06/2023] Open
Abstract
The polyadenosine tail (poly[A]-tail) is a universal modification of eukaryotic messenger RNAs (mRNAs) and non-coding RNAs (ncRNAs). In budding yeast, Pap1-synthesized mRNA poly(A) tails enhance export and translation, whereas Trf4/5-mediated polyadenylation of ncRNAs facilitates degradation by the exosome. Using direct RNA sequencing, we decipher the extent of poly(A) tail dynamics in yeast defective in all relevant exonucleases, deadenylases, and poly(A) polymerases. Predominantly ncRNA poly(A) tails are 20-60 adenosines long. Poly(A) tails of newly transcribed mRNAs are 50 adenosine long on average, with an upper limit of 200. Exonucleolysis by Trf5-assisted nuclear exosome and cytoplasmic deadenylases trim the tails to 40 adenosines on average. Surprisingly, PAN2/3 and CCR4-NOT deadenylase complexes have a large pool of non-overlapping substrates mainly defined by expression level. Finally, we demonstrate that mRNA poly(A) tail length strongly responds to growth conditions, such as heat and nutrient deprivation.
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16
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Cherkasova V, Iben JR, Pridham KJ, Kessler AC, Maraia RJ. The leucine-NH4+ uptake regulator Any1 limits growth as part of a general amino acid control response to loss of La protein by fission yeast. PLoS One 2021; 16:e0253494. [PMID: 34153074 PMCID: PMC8216550 DOI: 10.1371/journal.pone.0253494] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 06/04/2021] [Indexed: 11/19/2022] Open
Abstract
The sla1+ gene of Schizosachharoymces pombe encodes La protein which promotes proper processing of precursor-tRNAs. Deletion of sla1 (sla1Δ) leads to disrupted tRNA processing and sensitivity to target of rapamycin (TOR) inhibition. Consistent with this, media containing NH4+ inhibits leucine uptake and growth of sla1Δ cells. Here, transcriptome analysis reveals that genes upregulated in sla1Δ cells exhibit highly significant overalp with general amino acid control (GAAC) genes in relevant transcriptomes from other studies. Growth in NH4+ media leads to additional induced genes that are part of a core environmental stress response (CESR). The sla1Δ GAAC response adds to evidence linking tRNA homeostasis and broad signaling in S. pombe. We provide evidence that deletion of the Rrp6 subunit of the nuclear exosome selectively dampens a subset of GAAC genes in sla1Δ cells suggesting that nuclear surveillance-mediated signaling occurs in S. pombe. To study the NH4+-effects, we isolated sla1Δ spontaneous revertants (SSR) of the slow growth phenotype and found that GAAC gene expression and rapamycin hypersensitivity were also reversed. Genome sequencing identified a F32V substitution in Any1, a known negative regulator of NH4+-sensitive leucine uptake linked to TOR. We show that 3H-leucine uptake by SSR-any1-F32V cells in NH4+-media is more robust than by sla1Δ cells. Moreover, F32V may alter any1+ function in sla1Δ vs. sla1+ cells in a distinctive way. Thus deletion of La, a tRNA processing factor leads to a GAAC response involving reprogramming of amino acid metabolism, and isolation of the any1-F32V rescuing mutant provides an additional specific link.
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Affiliation(s)
- Vera Cherkasova
- Kelly@DeWitt, Inc, National Library of Medicine, National Institutes of Health, Bethesda, MD, United States of America
| | - James R. Iben
- Molecular Genomics Core, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States of America
| | - Kevin J. Pridham
- Fralin Biomedical Research Institute at Virginia Tech, Roanoke, VA, United States of America
| | - Alan C. Kessler
- Section on Molecular and Cell Biology, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD United States of America
| | - Richard J. Maraia
- Section on Molecular and Cell Biology, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD United States of America
- * E-mail:
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17
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Matia-González AM, Jabre I, Laing EE, Gerber AP. Oxidative stress induces coordinated remodeling of RNA-enzyme interactions. iScience 2021; 24:102753. [PMID: 34278261 PMCID: PMC8261671 DOI: 10.1016/j.isci.2021.102753] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 06/01/2021] [Accepted: 06/16/2021] [Indexed: 11/28/2022] Open
Abstract
RNA-binding proteins (RBPs) are key post-transcriptional regulators that play a substantial role during stress adaptation. Recent proteome-wide surveys have uncovered a large number of new and “unconventional” RBPs such as metabolic enzymes, yet little is known about the reconfiguration of the RNA-binding proteome (RBPome) and RNA-enzyme interactions in response to cellular stress. Here, we applied RNA-interactome capture to monitor the dynamics of the mRBPome upon mild oxidative stress in the yeast Saccharomyces cerevisiae. Among the 257 proteins that significantly changed RNA associations, we observed the coordinated remodeling of RNA-binding enzymes — particularly of the central carbon metabolism — that complemented known metabolic responses. Furthermore, we recognized the propensity for paralogous specific alterations of enzyme-RNA interactions. Our results suggest coordinated cross talk between RNA-enzyme interactions and intermediary metabolism to maintain the physiological and molecular balance upon oxidative stress, perhaps through specialization of paralogous during evolution. Oxidative stress induces the rearrangement of 257 proteins on polyadenylated RNAs Coordinated response of RNA-enzyme interactions and metabolism Yeast RNA-binding enzymes are paralog specific Integration of three different mass spectrometry analysis tools
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Affiliation(s)
- Ana M Matia-González
- Department of Microbial Sciences, School of Biosciences and Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, GU2 7XH, UK.,Department of Biochemistry and Molecular Biology I, Faculty of Sciences, University of Granada, Avda Fuentenueva s/n, Granada 18071, Spain
| | - Ibtissam Jabre
- Department of Microbial Sciences, School of Biosciences and Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, GU2 7XH, UK
| | - Emma E Laing
- Department of Microbial Sciences, School of Biosciences and Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, GU2 7XH, UK
| | - André P Gerber
- Department of Microbial Sciences, School of Biosciences and Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, GU2 7XH, UK
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18
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Jarrous N, Mani D, Ramanathan A. Coordination of transcription and processing of tRNA. FEBS J 2021; 289:3630-3641. [PMID: 33929081 DOI: 10.1111/febs.15904] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 04/02/2021] [Accepted: 04/28/2021] [Indexed: 12/17/2022]
Abstract
Coordination of transcription and processing of RNA is a basic principle in regulation of gene expression in eukaryotes. In the case of mRNA, coordination is primarily founded on a co-transcriptional processing mechanism by which a nascent precursor mRNA undergoes maturation via cleavage and modification by the transcription machinery. A similar mechanism controls the biosynthesis of rRNA. However, the coordination of transcription and processing of tRNA, a rather short transcript, remains unknown. Here, we present a model for high molecular weight initiation complexes of human RNA polymerase III that assemble on tRNA genes and process precursor transcripts to mature forms. These multifunctional initiation complexes may support co-transcriptional processing, such as the removal of the 5' leader of precursor tRNA by RNase P. Based on this model, maturation of tRNA is predetermined prior to transcription initiation.
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Affiliation(s)
- Nayef Jarrous
- Microbiology and Molecular Genetics, Institute of Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Dhivakar Mani
- Microbiology and Molecular Genetics, Institute of Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Aravind Ramanathan
- Microbiology and Molecular Genetics, Institute of Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
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19
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Das M, Zattas D, Zinder JC, Wasmuth EV, Henri J, Lima CD. Substrate discrimination and quality control require each catalytic activity of TRAMP and the nuclear RNA exosome. Proc Natl Acad Sci U S A 2021; 118:e2024846118. [PMID: 33782132 PMCID: PMC8040639 DOI: 10.1073/pnas.2024846118] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Quality control requires discrimination between functional and aberrant species to selectively target aberrant substrates for destruction. Nuclear RNA quality control in Saccharomyces cerevisiae includes the TRAMP complex that marks RNA for decay via polyadenylation followed by helicase-dependent 3' to 5' degradation by the RNA exosome. Using reconstitution biochemistry, we show that polyadenylation and helicase activities of TRAMP cooperate with processive and distributive exoribonuclease activities of the nuclear RNA exosome to protect stable RNA from degradation while selectively targeting and degrading less stable RNA. Substrate discrimination is lost when the distributive exoribonuclease activity of Rrp6 is inactivated, leading to degradation of stable and unstable RNA species. These data support a proofreading mechanism in which deadenylation by Rrp6 competes with Mtr4-dependent degradation to protect stable RNA while selectively targeting and degrading unstable RNA.
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Affiliation(s)
- Mom Das
- Structural Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065
| | - Dimitrios Zattas
- Structural Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065
| | - John C Zinder
- Structural Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065
- Tri-Institutional Training Program in Chemical Biology, Memorial Sloan Kettering Cancer Center, New York, NY 10065
| | - Elizabeth V Wasmuth
- Structural Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065
| | - Julien Henri
- Structural Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065
| | - Christopher D Lima
- Structural Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065;
- HHMI, Memorial Sloan Kettering Cancer Center, New York, NY 10065
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20
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Novačić A, Beauvais V, Oskomić M, Štrbac L, Dantec AL, Rahmouni AR, Stuparević I. Yeast RNA exosome activity is necessary for maintaining cell wall stability through proper protein glycosylation. Mol Biol Cell 2021; 32:363-375. [PMID: 33439673 PMCID: PMC8098854 DOI: 10.1091/mbc.e20-08-0544-t] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 11/25/2020] [Accepted: 01/06/2021] [Indexed: 12/01/2022] Open
Abstract
Nuclear RNA exosome is the main 3'→5' RNA degradation and processing complex in eukaryotic cells and its dysregulation therefore impacts gene expression and viability. In this work we show that RNA exosome activity is necessary for maintaining cell wall stability in yeast Saccharomyces cerevisiae. While the essential RNA exosome catalytic subunit Dis3 provides exoribonuclease catalytic activity, the second catalytic subunit Rrp6 has a noncatalytic role in this process. RNA exosome cofactors Rrp47 and Air1/2 are also involved. RNA exosome mutants undergo osmoremedial cell lysis at high temperature or at physiological temperature upon treatment with cell wall stressors. Finally, we show that a defect in protein glycosylation is a major reason for cell wall instability of RNA exosome mutants. Genes encoding enzymes that act in the early steps of the protein glycosylation pathway are down-regulated at high temperature in cells lacking Rrp6 protein or Dis3 exoribonuclease activity and overexpression of the essential enzyme Psa1, that catalyzes synthesis of the mannosylation precursor, suppresses temperature sensitivity and aberrant morphology of these cells. Furthermore, this defect is connected to a temperature-dependent increase in accumulation of noncoding RNAs transcribed from loci of relevant glycosylation-related genes.
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Affiliation(s)
- Ana Novačić
- Laboratory of Biochemistry, Department of Chemistry and Biochemistry, Faculty of Food Technology and Biotechnology, University of Zagreb, Zagreb, Croatia
| | - Valentin Beauvais
- Centre de Biophysique Moléculaire, UPR 4301 du CNRS, 45071 Orléans, France
| | - Marina Oskomić
- Laboratory of Biochemistry, Department of Chemistry and Biochemistry, Faculty of Food Technology and Biotechnology, University of Zagreb, Zagreb, Croatia
| | - Lucija Štrbac
- Laboratory of Biochemistry, Department of Chemistry and Biochemistry, Faculty of Food Technology and Biotechnology, University of Zagreb, Zagreb, Croatia
| | - Aurélia Le Dantec
- Centre de Biophysique Moléculaire, UPR 4301 du CNRS, 45071 Orléans, France
| | - A. Rachid Rahmouni
- Centre de Biophysique Moléculaire, UPR 4301 du CNRS, 45071 Orléans, France
| | - Igor Stuparević
- Laboratory of Biochemistry, Department of Chemistry and Biochemistry, Faculty of Food Technology and Biotechnology, University of Zagreb, Zagreb, Croatia
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21
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Olsen KJ, Johnson SJ. Mtr4 RNA helicase structures and interactions. Biol Chem 2021; 402:605-616. [PMID: 33857361 DOI: 10.1515/hsz-2020-0329] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 12/10/2020] [Indexed: 01/19/2023]
Abstract
Mtr4 is a Ski2-like RNA helicase that plays a central role in RNA surveillance and degradation pathways as an activator of the RNA exosome. Multiple crystallographic and cryo-EM studies over the past 10 years have revealed important insight into the Mtr4 structure and interactions with protein and nucleic acid binding partners. These structures place Mtr4 at the center of a dynamic process that recruits RNA substrates and presents them to the exosome. In this review, we summarize the available Mtr4 structures and highlight gaps in our current understanding.
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Affiliation(s)
- Keith J Olsen
- Department of Chemistry and Biochemistry, Utah State University, Logan, UT84322-0300, USA
| | - Sean J Johnson
- Department of Chemistry and Biochemistry, Utah State University, Logan, UT84322-0300, USA
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22
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Lau B, Cheng J, Flemming D, La Venuta G, Berninghausen O, Beckmann R, Hurt E. Structure of the Maturing 90S Pre-ribosome in Association with the RNA Exosome. Mol Cell 2020; 81:293-303.e4. [PMID: 33326748 DOI: 10.1016/j.molcel.2020.11.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 10/01/2020] [Accepted: 11/04/2020] [Indexed: 12/12/2022]
Abstract
Ribosome assembly is catalyzed by numerous trans-acting factors and coupled with irreversible pre-rRNA processing, driving the pathway toward mature ribosomal subunits. One decisive step early in this progression is removal of the 5' external transcribed spacer (5'-ETS), an RNA extension at the 18S rRNA that is integrated into the huge 90S pre-ribosome structure. Upon endo-nucleolytic cleavage at an internal site, A1, the 5'-ETS is separated from the 18S rRNA and degraded. Here we present biochemical and cryo-electron microscopy analyses that depict the RNA exosome, a major 3'-5' exoribonuclease complex, in a super-complex with the 90S pre-ribosome. The exosome is docked to the 90S through its co-factor Mtr4 helicase, a processive RNA duplex-dismantling helicase, which strategically positions the exosome at the base of 5'-ETS helices H9-H9', which are dislodged in our 90S-exosome structures. These findings suggest a direct role of the exosome in structural remodeling of the 90S pre-ribosome to drive eukaryotic ribosome synthesis.
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Affiliation(s)
- Benjamin Lau
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Jingdong Cheng
- Gene Center, Department of Biochemistry and Center for Integrated Protein Science Munich (CiPSM), Ludwig-Maximilians-Universität München, Feodor-Lynen-Straße 25, 81377 Munich, Germany
| | - Dirk Flemming
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Giuseppe La Venuta
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Otto Berninghausen
- Gene Center, Department of Biochemistry and Center for Integrated Protein Science Munich (CiPSM), Ludwig-Maximilians-Universität München, Feodor-Lynen-Straße 25, 81377 Munich, Germany
| | - Roland Beckmann
- Gene Center, Department of Biochemistry and Center for Integrated Protein Science Munich (CiPSM), Ludwig-Maximilians-Universität München, Feodor-Lynen-Straße 25, 81377 Munich, Germany.
| | - Ed Hurt
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, 69120 Heidelberg, Germany.
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23
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Aguilar LC, Paul B, Reiter T, Gendron L, Arul Nambi Rajan A, Montpetit R, Trahan C, Pechmann S, Oeffinger M, Montpetit B. Altered rRNA processing disrupts nuclear RNA homeostasis via competition for the poly(A)-binding protein Nab2. Nucleic Acids Res 2020; 48:11675-11694. [PMID: 33137177 PMCID: PMC7672433 DOI: 10.1093/nar/gkaa964] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 10/06/2020] [Accepted: 10/12/2020] [Indexed: 12/13/2022] Open
Abstract
RNA-binding proteins (RBPs) are key mediators of RNA metabolism. Whereas some RBPs exhibit narrow transcript specificity, others function broadly across both coding and non-coding RNAs. Here, in Saccharomyces cerevisiae, we demonstrate that changes in RBP availability caused by disruptions to distinct cellular processes promote a common global breakdown in RNA metabolism and nuclear RNA homeostasis. Our data shows that stabilization of aberrant ribosomal RNA (rRNA) precursors in an enp1-1 mutant causes phenotypes similar to RNA exosome mutants due to nucleolar sequestration of the poly(A)-binding protein (PABP) Nab2. Decreased nuclear PABP availability is accompanied by genome-wide changes in RNA metabolism, including increased pervasive transcripts levels and snoRNA processing defects. These phenotypes are mitigated by overexpression of PABPs, inhibition of rDNA transcription, or alterations in TRAMP activity. Our results highlight the need for cells to maintain poly(A)-RNA levels in balance with PABPs and other RBPs with mutable substrate specificity across nucleoplasmic and nucleolar RNA processes.
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Affiliation(s)
- Lisbeth-Carolina Aguilar
- Department for Systems Biology, Institut de recherches cliniques de Montréal (IRCM), Montréal, QC, Canada
| | - Biplab Paul
- Department of Cell Biology, University of Alberta, Edmonton, Canada
| | - Taylor Reiter
- Food Science Graduate Group, University of California Davis, Davis, CA, USA
| | - Louis Gendron
- Département de biochimie et médecine moléculaire, Université de Montréal, Montréal, QC, Canada
| | - Arvind Arul Nambi Rajan
- Biochemistry, Molecular, Cellular and Developmental Biology Graduate Group, University of California Davis, Davis, CA, USA
| | - Rachel Montpetit
- Department of Viticulture and Enology, University of California Davis, Davis, CA, USA
| | - Christian Trahan
- Department for Systems Biology, Institut de recherches cliniques de Montréal (IRCM), Montréal, QC, Canada
| | - Sebastian Pechmann
- Département de biochimie et médecine moléculaire, Université de Montréal, Montréal, QC, Canada
| | - Marlene Oeffinger
- Department for Systems Biology, Institut de recherches cliniques de Montréal (IRCM), Montréal, QC, Canada
- Département de biochimie et médecine moléculaire, Université de Montréal, Montréal, QC, Canada
- Division of Experimental Medicine, McGill University, Montreal, QC, Canada
| | - Ben Montpetit
- Department of Cell Biology, University of Alberta, Edmonton, Canada
- Food Science Graduate Group, University of California Davis, Davis, CA, USA
- Biochemistry, Molecular, Cellular and Developmental Biology Graduate Group, University of California Davis, Davis, CA, USA
- Department of Viticulture and Enology, University of California Davis, Davis, CA, USA
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