1
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Chaves-Arquero B, Pérez-Cañadillas JM. The Nrd1-Nab3-Sen1 transcription termination complex from a structural perspective. Biochem Soc Trans 2023:233089. [PMID: 37222282 DOI: 10.1042/bst20221418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 04/26/2023] [Accepted: 05/11/2023] [Indexed: 05/25/2023]
Abstract
A substantial part of living cells activity involves transcription regulation. The RNA polymerases responsible for this job need to know 'where/when' to start and stop in the genome, answers that may change throughout life and upon external stimuli. In Saccharomyces cerevisiae, RNA Pol II transcription termination can follow two different routes: the poly(A)-dependent one used for most of the mRNAs and the Nrd1/Nab3/Sen1 (NNS) pathway for non-coding RNAs (ncRNA). The NNS targets include snoRNAs and cryptic unstable transcripts (CUTs) generated by pervasive transcription. This review recapitulates the state of the art in structural biology and biophysics of the Nrd1, Nab3 and Sen1 components of the NNS complex, with special attention to their domain structures and interactions with peptide and RNA motifs, and their heterodimerization. This structural information is put into the context of the NNS termination mechanism together with possible prospects for evolution in the field.
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Affiliation(s)
- Belén Chaves-Arquero
- Department of Structural and Chemical Biology, Center for Biological Research 'Margarita Salas', CIB, CSIC, Av. Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - José Manuel Pérez-Cañadillas
- Department of Biological Physical Chemistry, Institute of Physical-Chemistry 'Blas Cabrera', CSIC, C/Serrano 119, 28006 Madrid, Spain
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2
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Aizu T, Suzuki T, Kido A, Nagai K, Kobayashi A, Sugiura R, Ito Y, Mishima M. Domain selective labeling for NMR studies of multidomain proteins by domain ligation using highly active sortase A. Biochim Biophys Acta Gen Subj 2019; 1864:129419. [PMID: 31449838 DOI: 10.1016/j.bbagen.2019.129419] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 08/14/2019] [Accepted: 08/21/2019] [Indexed: 11/19/2022]
Abstract
Structural study of multidomain proteins using NMR is an emerging issue for understanding biological functions. To this end, domain-specific labeling is expected to be a key technology for facilitating the NMR-assignment process and for collecting distance information via spin labeling. To obtain domain-specific labeled samples, use of sortase A as a protein ligation tool is a viable approach. Sortase A enables ligation of separately expressed proteins (domains) through the Leu-Pro-X-Thr-Gly linker. However, the ligation reaction mediated by sortase A is not efficient. Poor yield and long reaction times hamper large-scale preparation using sortase A. Here we report the application of highly active sortases to NMR analyses. Optimal yields can be achieved within several hours when the ligation reaction are mediated by highly active sortases at 4 °C. We propose that this protocol can contribute to structural analyses of multidomain proteins by NMR.
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Affiliation(s)
- Takahiro Aizu
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, 1-1 Minamiosawa, Hachioji 192-0397, Japan
| | - Takumi Suzuki
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, 1-1 Minamiosawa, Hachioji 192-0397, Japan
| | - Akihiro Kido
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, 1-1 Minamiosawa, Hachioji 192-0397, Japan
| | - Kan Nagai
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, 1-1 Minamiosawa, Hachioji 192-0397, Japan
| | - Ayaho Kobayashi
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, 1-1 Minamiosawa, Hachioji 192-0397, Japan
| | - Reiko Sugiura
- Laboratory of Molecular Pharmacogenomics, Department of Pharmaceutical Sciences, Faculty of Pharmacy, Kindai University, 3-4-1 Kowake, Higashi-Osaka 577-8502, Japan
| | - Yutaka Ito
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, 1-1 Minamiosawa, Hachioji 192-0397, Japan
| | - Masaki Mishima
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, 1-1 Minamiosawa, Hachioji 192-0397, Japan.
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3
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Collin P, Jeronimo C, Poitras C, Robert F. RNA Polymerase II CTD Tyrosine 1 Is Required for Efficient Termination by the Nrd1-Nab3-Sen1 Pathway. Mol Cell 2019; 73:655-669.e7. [PMID: 30639244 DOI: 10.1016/j.molcel.2018.12.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 09/09/2018] [Accepted: 11/29/2018] [Indexed: 12/15/2022]
Abstract
In Saccharomyces cerevisiae, transcription termination at protein-coding genes is coupled to the cleavage of the nascent transcript, whereas most non-coding RNA transcription relies on a cleavage-independent termination pathway involving Nrd1, Nab3, and Sen1 (NNS). Termination involves RNA polymerase II CTD phosphorylation, but a systematic analysis of the contribution of individual residues would improve our understanding of the role of the CTD in this process. Here we investigated the effect of mutating phosphorylation sites in the CTD on termination. We observed widespread termination defects at protein-coding genes in mutants for Ser2 or Thr4 but rare defects in Tyr1 mutants for this genes class. Instead, mutating Tyr1 led to widespread termination defects at non-coding genes terminating via NNS. Finally, we showed that Tyr1 is important for pausing in the 5' end of genes and that slowing down transcription suppresses termination defects. Our work highlights the importance of Tyr1-mediated pausing in NNS-dependent termination.
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Affiliation(s)
- Pierre Collin
- Institut de recherches cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, QC, H2W 1R7, Canada
| | - Célia Jeronimo
- Institut de recherches cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, QC, H2W 1R7, Canada
| | - Christian Poitras
- Institut de recherches cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, QC, H2W 1R7, Canada
| | - François Robert
- Institut de recherches cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, QC, H2W 1R7, Canada; Département de Médecine, Faculté de Médecine, Université de Montréal, 2900 Boulevard Edouard-Montpetit, Montréal, QC H3T 1J4, Canada.
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4
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Abstract
The role of transcription factors (TFs) on nucleosome positioning, RNA polymerase recruitment, and transcription initiation has been extensively characterized. Here, we propose that a subset of TFs such as Reb1, Abf1, Rap1, and TFIIIB also serve a major function in partitioning transcription units by assisting the Nrd1p-Nab3p-Sen1p Pol II termination pathway.
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Affiliation(s)
- Kevin Roy
- a Department of Chemistry and Biochemistry and the Molecular Biology Institute , University of California Los Angeles , CA , USA
| | - Guillaume F Chanfreau
- a Department of Chemistry and Biochemistry and the Molecular Biology Institute , University of California Los Angeles , CA , USA
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5
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Kobayashi A, Kanaba T, Satoh R, Ito Y, Sugiura R, Mishima M. Chemical shift assignments of the first and second RRMs of Nrd1, a fission yeast MAPK-target RNA binding protein. Biomol NMR Assign 2017; 11:123-126. [PMID: 28284018 DOI: 10.1007/s12104-017-9731-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 02/17/2017] [Indexed: 06/06/2023]
Abstract
Negative regulator differentiation 1 (Nrd1), a fission yeast RNA binding protein, modulates cytokinesis and sexual development and contributes to stress granule formation in response to environmental stresses. Nrd1 comprises four RRM domains and binds and stabilizes Cdc4 mRNA that encodes the myosin II light chain. Nrd1 binds the Cpc2 fission-yeast RACK1 homolog, and the interaction promotes Nrd1 localization to stress granules. Interestingly, Pmk1 mitogen-activated protein kinase phosphorylates Thr40 in the unstructured N-terminal region and Thr126 in the first RRM domain of Nrd1. Phosphorylation significantly reduces RNA-binding activity and likely modulates Nrd1 function. To reveal the relationship between the structure and function of Nrd1 and how phosphorylation affects structure, we used heteronuclear NMR techniques to investigate the three-dimensional structure of Nrd1. Here we report the 1H, 13C, and 15N resonance assignments of RRM1-RRM2 (residues 108-284) comprising the first and second RRMs obtained using heteronuclear NMR techniques. Secondary structures derived from the chemical shifts are reported. These data should contribute to the understanding of the three-dimensional structure of the RRM1-RRM2 region of Nrd1 and the perturbation caused by phosphorylation.
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Affiliation(s)
- Ayaho Kobayashi
- Graduate School of Science and Engineering, Tokyo Metropolitan University, 1-1 Minamiosawa, Hachioji, 192-0397, Japan
| | - Teppei Kanaba
- Graduate School of Science and Engineering, Tokyo Metropolitan University, 1-1 Minamiosawa, Hachioji, 192-0397, Japan
- Bruker BioSpin K. K., 3-9, Moriya-cho, Kanagawa, Yokohama, 221-0022, Japan
| | - Ryosuke Satoh
- Laboratory of Molecular Pharmacogenomics, Department of Pharmaceutical Sciences, Faculty of Pharmacy, Kindai University, 3-4-1 Kowake, Higashi-Osaka, 577-8502, Japan
| | - Yutaka Ito
- Graduate School of Science and Engineering, Tokyo Metropolitan University, 1-1 Minamiosawa, Hachioji, 192-0397, Japan
| | - Reiko Sugiura
- Laboratory of Molecular Pharmacogenomics, Department of Pharmaceutical Sciences, Faculty of Pharmacy, Kindai University, 3-4-1 Kowake, Higashi-Osaka, 577-8502, Japan
| | - Masaki Mishima
- Graduate School of Science and Engineering, Tokyo Metropolitan University, 1-1 Minamiosawa, Hachioji, 192-0397, Japan.
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6
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Lemay JF, Marguerat S, Larochelle M, Liu X, van Nues R, Hunyadkürti J, Hoque M, Tian B, Granneman S, Bähler J, Bachand F. The Nrd1-like protein Seb1 coordinates cotranscriptional 3' end processing and polyadenylation site selection. Genes Dev 2017; 30:1558-72. [PMID: 27401558 PMCID: PMC4949328 DOI: 10.1101/gad.280222.116] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 06/10/2016] [Indexed: 11/25/2022]
Abstract
Termination of RNA polymerase II (RNAPII) transcription is associated with RNA 3' end formation. For coding genes, termination is initiated by the cleavage/polyadenylation machinery. In contrast, a majority of noncoding transcription events in Saccharomyces cerevisiae does not rely on RNA cleavage for termination but instead terminates via a pathway that requires the Nrd1-Nab3-Sen1 (NNS) complex. Here we show that the Schizosaccharomyces pombe ortholog of Nrd1, Seb1, does not function in NNS-like termination but promotes polyadenylation site selection of coding and noncoding genes. We found that Seb1 associates with 3' end processing factors, is enriched at the 3' end of genes, and binds RNA motifs downstream from cleavage sites. Importantly, a deficiency in Seb1 resulted in widespread changes in 3' untranslated region (UTR) length as a consequence of increased alternative polyadenylation. Given that Seb1 levels affected the recruitment of conserved 3' end processing factors, our findings indicate that the conserved RNA-binding protein Seb1 cotranscriptionally controls alternative polyadenylation.
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Affiliation(s)
- Jean-François Lemay
- RNA Group, Department of Biochemistry, Université de Sherbrooke, Sherbrooke, Quebec J1E 4K8, Canada
| | - Samuel Marguerat
- MRC Clinical Sciences Centre (CSC), London W12 0NN, United Kingdom; Institute of Clinical Sciences (ICS), Faculty of Medicine, Imperial College London, London W12 0NN, United Kingdom
| | - Marc Larochelle
- RNA Group, Department of Biochemistry, Université de Sherbrooke, Sherbrooke, Quebec J1E 4K8, Canada
| | - Xiaochuan Liu
- Department of Microbiology, Biochemistry, and Molecular Genetics, Rutgers New Jersey Medical School, Newark, New Jersey 07103, USA; Rutgers Cancer Institute of New Jersey, Newark, New Jersey 08903, USA
| | - Rob van Nues
- Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
| | - Judit Hunyadkürti
- RNA Group, Department of Biochemistry, Université de Sherbrooke, Sherbrooke, Quebec J1E 4K8, Canada
| | - Mainul Hoque
- Department of Microbiology, Biochemistry, and Molecular Genetics, Rutgers New Jersey Medical School, Newark, New Jersey 07103, USA; Rutgers Cancer Institute of New Jersey, Newark, New Jersey 08903, USA
| | - Bin Tian
- Department of Microbiology, Biochemistry, and Molecular Genetics, Rutgers New Jersey Medical School, Newark, New Jersey 07103, USA; Rutgers Cancer Institute of New Jersey, Newark, New Jersey 08903, USA
| | - Sander Granneman
- Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh EH9 3BF, United Kingdom; Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
| | - Jürg Bähler
- Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, United Kingdom
| | - François Bachand
- RNA Group, Department of Biochemistry, Université de Sherbrooke, Sherbrooke, Quebec J1E 4K8, Canada
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7
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Larochelle M, Hunyadkürti J, Bachand F. Polyadenylation site selection: linking transcription and RNA processing via a conserved carboxy-terminal domain (CTD)-interacting protein. Curr Genet 2016; 63:195-199. [PMID: 27582274 DOI: 10.1007/s00294-016-0645-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 08/27/2016] [Indexed: 12/29/2022]
Abstract
Despite the fact that the process of mRNA polyadenylation has been known for more than 40 years, a detailed understating of the mechanism underlying polyadenylation site selection is still far from complete. As 3' end processing is intimately associated with RNA polymerase II (RNAPII) transcription, factors that can successively interact with the transcription machinery and recognize cis-acting sequences on the nascent pre-mRNA would be well suited to contribute to poly(A) site selection. Studies using the fission yeast Schizosaccharomyces pombe have recently identified Seb1, a protein that shares homology with Saccharomyces cerevisiae Nrd1 and human SCAF4/8, and that is critical for poly(A) site selection. Seb1 binds to the C-terminal domain (CTD) of RNAPII via a conserved CTD-interaction domain and recognizes specific sequence motifs clustered downstream of the polyadenylation site on the uncleaved pre-mRNA. In this short review, we summarize insights into Seb1-dependent poly(A) site selection and discuss some unanswered questions regarding its molecular mechanism and conservation.
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Affiliation(s)
- Marc Larochelle
- RNA Group, Department of Biochemistry, Université de Sherbrooke, 3201 Jean-Mignault, Sherbrooke, Québec, J1E 4K8, Canada
| | - Judit Hunyadkürti
- RNA Group, Department of Biochemistry, Université de Sherbrooke, 3201 Jean-Mignault, Sherbrooke, Québec, J1E 4K8, Canada
| | - François Bachand
- RNA Group, Department of Biochemistry, Université de Sherbrooke, 3201 Jean-Mignault, Sherbrooke, Québec, J1E 4K8, Canada.
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8
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Abstract
Termination of RNA polymerase II (RNAPII) transcription is a fundamental step of gene expression that involves the release of the nascent transcript and dissociation of RNAPII from the DNA template. As transcription termination is intimately linked to RNA 3' end processing, termination pathways have a key decisive influence on the fate of the transcribed RNA. Quite remarkably, when reaching the 3' end of genes, a substantial fraction of RNAPII fail to terminate transcription, requiring the contribution of alternative or "fail-safe" mechanisms of termination to release the polymerase. This point of view covers redundant mechanisms of transcription termination and how they relate to conventional termination models. In particular, we expand on recent findings that propose a reverse torpedo model of termination, in which the 3'5' exonucleolytic activity of the RNA exosome targets transcription events associated with paused and backtracked RNAPII.
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Affiliation(s)
- Jean-François Lemay
- a Department of Biochemistry ; Faculté de Médecine et des Sciences de la Santé; Université de Sherbrooke; Pavillon de Recherche Appliquée sur le Cancer (PRAC) ; Sherbrooke, Quebec
| | - François Bachand
- a Department of Biochemistry ; Faculté de Médecine et des Sciences de la Santé; Université de Sherbrooke; Pavillon de Recherche Appliquée sur le Cancer (PRAC) ; Sherbrooke, Quebec
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9
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Abstract
The RNA polymerase II transcription cycle is often divided into three major stages: initiation, elongation, and termination. Research over the last decade has blurred these divisions and emphasized the tightly regulated transitions that occur as RNA polymerase II synthesizes a transcript from start to finish. Transcription termination, the process that marks the end of transcription elongation, is regulated by proteins that interact with the polymerase, nascent transcript, and/or chromatin template. The failure to terminate transcription can cause accumulation of aberrant transcripts and interfere with transcription at downstream genes. Here, we review the mechanism, regulation, and physiological impact of a termination pathway that targets small noncoding transcripts produced by RNA polymerase II. We emphasize the Nrd1-Nab3-Sen1 pathway in yeast, in which the process has been extensively studied. The importance of understanding small RNA termination pathways is underscored by the need to control noncoding transcription in eukaryotic genomes.
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Affiliation(s)
- Karen M Arndt
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15260;
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10
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Marina DB, Shankar S, Natarajan P, Finn KJ, Madhani HD. A conserved ncRNA-binding protein recruits silencing factors to heterochromatin through an RNAi-independent mechanism. Genes Dev 2013; 27:1851-6. [PMID: 24013500 PMCID: PMC3778239 DOI: 10.1101/gad.226019.113] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Long noncoding RNAs (lncRNAs) can trigger repressive chromatin, but how they recruit silencing factors remains unclear. In Schizosaccharomyces pombe, heterochromatin assembly on transcribed noncoding pericentromeric repeats requires both RNAi and RNAi-independent mechanisms. In Saccharomyces cerevisiae, which lacks a repressive chromatin mark (H3K9me [methylated Lys9 on histone H3]), unstable ncRNAs are recognized by the RNA-binding protein Nrd1. We show that the S. pombe ortholog Seb1 is associated with pericentromeric lncRNAs. Individual mutation of dcr1+ (Dicer) or seb1+ results in equivalent partial reductions of pericentromeric H3K9me levels, but a double mutation eliminates this mark. Seb1 functions independently of RNAi by recruiting the NuRD (nucleosome remodeling and deacetylase)-related chromatin-modifying complex SHREC (Snf2-HDAC [histone deacetylase] repressor complex).
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Affiliation(s)
- Diana B Marina
- Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, California 94158, USA
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11
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Heo DH, Yoo I, Kong J, Lidschreiber M, Mayer A, Choi BY, Hahn Y, Cramer P, Buratowski S, Kim M. The RNA polymerase II C-terminal domain-interacting domain of yeast Nrd1 contributes to the choice of termination pathway and couples to RNA processing by the nuclear exosome. J Biol Chem 2013; 288:36676-90. [PMID: 24196955 DOI: 10.1074/jbc.m113.508267] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The RNA polymerase II (RNApII) C-terminal domain (CTD)-interacting domain (CID) proteins are involved in two distinct RNApII termination pathways and recognize different phosphorylated forms of CTD. To investigate the role of differential CTD-CID interactions in the choice of termination pathway, we altered the CTD-binding specificity of Nrd1 by domain swapping. Nrd1 with the CID from Rtt103 (Nrd1(CID(Rtt103))) causes read-through transcription at many genes, but can also trigger termination where multiple Nrd1/Nab3-binding sites and the Ser(P)-2 CTD co-exist. Therefore, CTD-CID interactions target specific termination complexes to help choose an RNApII termination pathway. Interactions of Nrd1 with both CTD and nascent transcripts contribute to efficient termination by the Nrd1 complex. Surprisingly, replacing the Nrd1 CID with that from Rtt103 reduces binding to Rrp6/Trf4, and RNA transcripts terminated by Nrd1(CID(Rtt103)) are predominantly processed by core exosome. Thus, the Nrd1 CID couples Ser(P)-5 CTD not only to termination, but also to RNA processing by the nuclear exosome.
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Affiliation(s)
- Dong-hyuk Heo
- From the Center for RNA Research, Institute for Basic Science and
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12
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Loya TJ, O'Rourke TW, Degtyareva N, Reines D. A network of interdependent molecular interactions describes a higher order Nrd1-Nab3 complex involved in yeast transcription termination. J Biol Chem 2013; 288:34158-34167. [PMID: 24100036 DOI: 10.1074/jbc.m113.516765] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Nab3 and Nrd1 are yeast heterogeneous nuclear ribonucleoprotein (hnRNP)-like proteins that heterodimerize and bind RNA. Genetic and biochemical evidence reveals that they are integral to the termination of transcription of short non-coding RNAs by RNA polymerase II. Here we define a Nab3 mutation (nab3Δ134) that removes an essential part of the protein's C terminus but nevertheless can rescue, in trans, the phenotype resulting from a mutation in the RNA recognition motif of Nab3. This low complexity region of Nab3 appears intrinsically unstructured and can form a hydrogel in vitro. These data support a model in which multiple Nrd1-Nab3 heterodimers polymerize onto substrate RNA to effect termination, allowing complementation of one mutant Nab3 molecule by another lacking a different function. The self-association property of Nab3 adds to the previously documented interactions between these hnRNP-like proteins, RNA polymerase II, and the nascent transcript, leading to a network of nucleoprotein interactions that define a higher order Nrd1-Nab3 complex. This was underscored from the synthetic phenotypes of yeast strains with pairwise combinations of Nrd1 and Nab3 mutations known to affect their distinct biochemical activities. The mutations included a Nab3 self-association defect, a Nab3-Nrd1 heterodimerization defect, a Nrd1-polymerase II binding defect, and an Nab3-RNA recognition motif mutation. Although no single mutation was lethal, cells with any two mutations were not viable for four such pairings, and a fifth displayed a synthetic growth defect. These data strengthen the idea that a multiplicity of interactions is needed to assemble a higher order Nrd1-Nab3 complex that coats specific nascent RNAs in preparation for termination.
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Affiliation(s)
- Travis J Loya
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Thomas W O'Rourke
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Natalya Degtyareva
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Daniel Reines
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia 30322.
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13
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Chang CS, Clarke A, Pillus L. Suppression analysis of esa1 mutants in Saccharomyces cerevisiae links NAB3 to transcriptional silencing and nucleolar functions. G3 (Bethesda) 2012; 2:1223-32. [PMID: 23050233 DOI: 10.1534/g3.112.003558] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Accepted: 08/14/2012] [Indexed: 11/21/2022]
Abstract
The acetyltransferase Esa1 is essential in the yeast Saccharomyces cerevisiae and plays a critical role in multiple cellular processes. The most well-defined targets for Esa1 are lysine residues on histones. However, an increasing number of nonhistone proteins have recently been identified as substrates of Esa1. In this study, four genes (LYS20, LEU2, VAP1, and NAB3) were identified in a genetic screen as high-copy suppressors of the conditional temperature-sensitive lethality of an esa1 mutant. When expressed from a high-copy plasmid, each of these suppressors rescued the temperature-sensitivity of an esa1 mutant. Only NAB3 overexpression also rescued the rDNA-silencing defects of an esa1 mutant. Strengthening the connections between NAB3 and ESA1, mutants of nab3 displayed several phenotypes similar to those of esa1 mutants, including increased sensitivity to the topoisomerase I inhibitor camptothecin and defects in rDNA silencing and cell-cycle progression. In addition, nuclear localization of Nab3 was altered in the esa1 mutant. Finally, posttranslational acetylation of Nab3 was detected in vivo and found to be influenced by ESA1.
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