1
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Grzechnik P, Mischo HE. Fateful Decisions of Where to Cut the Line: Pathology Associated with Aberrant 3' End Processing and Transcription Termination. J Mol Biol 2024:168802. [PMID: 39321865 DOI: 10.1016/j.jmb.2024.168802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2024] [Revised: 09/17/2024] [Accepted: 09/19/2024] [Indexed: 09/27/2024]
Abstract
Aberrant gene expression lies at the heart of many pathologies. This review will point out how 3' end processing, the final mRNA-maturation step in the transcription cycle, is surprisingly prone to regulated as well as stochastic variations with a wide range of consequences. Whereas smaller variations contribute to the plasticity of gene expression, larger alternations to 3' end processing and coupled transcription termination can lead to pathological consequences. These can be caused by the local mutation of one gene or affect larger numbers of genes systematically, if aspects of the mechanisms of 3' end processing and transcription termination are altered.
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Affiliation(s)
- Pawel Grzechnik
- Division of Molecular and Cellular Function, School of Biological Sciences, University of Manchester, United Kingdom
| | - Hannah E Mischo
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, United Kingdom.
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2
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Rodríguez‐Molina JB, Turtola M. Birth of a poly(A) tail: mechanisms and control of mRNA polyadenylation. FEBS Open Bio 2023; 13:1140-1153. [PMID: 36416579 PMCID: PMC10315857 DOI: 10.1002/2211-5463.13528] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 11/17/2022] [Accepted: 11/22/2022] [Indexed: 11/24/2022] Open
Abstract
During their synthesis in the cell nucleus, most eukaryotic mRNAs undergo a two-step 3'-end processing reaction in which the pre-mRNA is cleaved and released from the transcribing RNA polymerase II and a polyadenosine (poly(A)) tail is added to the newly formed 3'-end. These biochemical reactions might appear simple at first sight (endonucleolytic RNA cleavage and synthesis of a homopolymeric tail), but their catalysis requires a multi-faceted enzymatic machinery, the cleavage and polyadenylation complex (CPAC), which is composed of more than 20 individual protein subunits. The activity of CPAC is further orchestrated by Poly(A) Binding Proteins (PABPs), which decorate the poly(A) tail during its synthesis and guide the mRNA through subsequent gene expression steps. Here, we review the structure, molecular mechanism, and regulation of eukaryotic mRNA 3'-end processing machineries with a focus on the polyadenylation step. We concentrate on the CPAC and PABPs from mammals and the budding yeast, Saccharomyces cerevisiae, because these systems are the best-characterized at present. Comparison of their functions provides valuable insights into the principles of mRNA 3'-end processing.
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Affiliation(s)
| | - Matti Turtola
- Department of Life TechnologiesUniversity of TurkuFinland
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3
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Abstract
Formation of the 3' end of a eukaryotic mRNA is a key step in the production of a mature transcript. This process is mediated by a number of protein factors that cleave the pre-mRNA, add a poly(A) tail, and regulate transcription by protein dephosphorylation. Cleavage and polyadenylation specificity factor (CPSF) in humans, or cleavage and polyadenylation factor (CPF) in yeast, coordinates these enzymatic activities with each other, with RNA recognition, and with transcription. The site of pre-mRNA cleavage can strongly influence the translation, stability, and localization of the mRNA. Hence, cleavage site selection is highly regulated. The length of the poly(A) tail is also controlled to ensure that every transcript has a similar tail when it is exported from the nucleus. In this review, we summarize new mechanistic insights into mRNA 3'-end processing obtained through structural studies and biochemical reconstitution and outline outstanding questions in the field.
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Affiliation(s)
- Vytautė Boreikaitė
- Medical Research Council Laboratory of Molecular Biology, Cambridge, United Kingdom;
| | - Lori A Passmore
- Medical Research Council Laboratory of Molecular Biology, Cambridge, United Kingdom;
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4
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Soni K, Sivadas A, Horvath A, Dobrev N, Hayashi R, Kiss L, Simon B, Wild K, Sinning I, Fischer T. Mechanistic insights into RNA surveillance by the canonical poly(A) polymerase Pla1 of the MTREC complex. Nat Commun 2023; 14:772. [PMID: 36774373 PMCID: PMC9922296 DOI: 10.1038/s41467-023-36402-6] [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: 06/30/2022] [Accepted: 01/31/2023] [Indexed: 02/13/2023] Open
Abstract
The S. pombe orthologue of the human PAXT connection, Mtl1-Red1 Core (MTREC), is an eleven-subunit complex that targets cryptic unstable transcripts (CUTs) to the nuclear RNA exosome for degradation. It encompasses the canonical poly(A) polymerase Pla1, responsible for polyadenylation of nascent RNA transcripts as part of the cleavage and polyadenylation factor (CPF/CPSF). In this study we identify and characterise the interaction between Pla1 and the MTREC complex core component Red1 and analyse the functional relevance of this interaction in vivo. Our crystal structure of the Pla1-Red1 complex shows that a 58-residue fragment in Red1 binds to the RNA recognition motif domain of Pla1 and tethers it to the MTREC complex. Structure-based Pla1-Red1 interaction mutations show that Pla1, as part of MTREC complex, hyper-adenylates CUTs for their efficient degradation. Interestingly, the Red1-Pla1 interaction is also required for the efficient assembly of the fission yeast facultative heterochromatic islands. Together, our data suggest a complex interplay between the RNA surveillance and 3'-end processing machineries.
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Affiliation(s)
- Komal Soni
- Heidelberg University Biochemistry Center (BZH), INF 328, D-69120, Heidelberg, Germany
| | - Anusree Sivadas
- The John Curtin School of Medical Research, The Australian National University, Canberra, ACT 2601, Australia
| | - Attila Horvath
- The John Curtin School of Medical Research, The Australian National University, Canberra, ACT 2601, Australia
| | - Nikolay Dobrev
- Heidelberg University Biochemistry Center (BZH), INF 328, D-69120, Heidelberg, Germany
| | - Rippei Hayashi
- The John Curtin School of Medical Research, The Australian National University, Canberra, ACT 2601, Australia
| | - Leo Kiss
- Heidelberg University Biochemistry Center (BZH), INF 328, D-69120, Heidelberg, Germany
| | - Bernd Simon
- European Molecular Biology Laboratory (EMBL), Meyerhofstr, 1, D-69117, Heidelberg, Germany
| | - Klemens Wild
- Heidelberg University Biochemistry Center (BZH), INF 328, D-69120, Heidelberg, Germany
| | - Irmgard Sinning
- Heidelberg University Biochemistry Center (BZH), INF 328, D-69120, Heidelberg, Germany.
| | - Tamás Fischer
- The John Curtin School of Medical Research, The Australian National University, Canberra, ACT 2601, Australia.
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5
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Muckenfuss LM, Migenda Herranz AC, Boneberg FM, Clerici M, Jinek M. Fip1 is a multivalent interaction scaffold for processing factors in human mRNA 3' end biogenesis. eLife 2022; 11:80332. [PMID: 36073787 PMCID: PMC9512404 DOI: 10.7554/elife.80332] [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: 05/17/2022] [Accepted: 09/07/2022] [Indexed: 11/25/2022] Open
Abstract
3′ end formation of most eukaryotic mRNAs is dependent on the assembly of a ~1.5 MDa multiprotein complex, that catalyzes the coupled reaction of pre-mRNA cleavage and polyadenylation. In mammals, the cleavage and polyadenylation specificity factor (CPSF) constitutes the core of the 3′ end processing machinery onto which the remaining factors, including cleavage stimulation factor (CstF) and poly(A) polymerase (PAP), assemble. These interactions are mediated by Fip1, a CPSF subunit characterized by high degree of intrinsic disorder. Here, we report two crystal structures revealing the interactions of human Fip1 (hFip1) with CPSF30 and CstF77. We demonstrate that CPSF contains two copies of hFip1, each binding to the zinc finger (ZF) domains 4 and 5 of CPSF30. Using polyadenylation assays we show that the two hFip1 copies are functionally redundant in recruiting one copy of PAP, thereby increasing the processivity of RNA polyadenylation. We further show that the interaction between hFip1 and CstF77 is mediated via a short motif in the N-terminal ‘acidic’ region of hFip1. In turn, CstF77 competitively inhibits CPSF-dependent PAP recruitment and 3′ polyadenylation. Taken together, these results provide a structural basis for the multivalent scaffolding and regulatory functions of hFip1 in 3′ end processing.
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Affiliation(s)
| | | | | | - Marcello Clerici
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Martin Jinek
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
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6
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Kumar A, Yu CWH, Rodríguez-Molina JB, Li XH, Freund SMV, Passmore LA. Dynamics in Fip1 regulate eukaryotic mRNA 3' end processing. Genes Dev 2021; 35:1510-1526. [PMID: 34593603 PMCID: PMC8559680 DOI: 10.1101/gad.348671.121] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Accepted: 09/09/2021] [Indexed: 01/11/2023]
Abstract
In this study, Kumar et al. characterized the structure–function relationship of the essential poly(A) factor Fip1. Using in vitro reconstitution and structural studies, the authors report that Fip1 dynamics within the 3′ end processing machinery are required to coordinate cleavage and polyadenylation. Cleavage and polyadenylation factor (CPF/CPSF) is a multiprotein complex essential for mRNA 3′ end processing in eukaryotes. It contains an endonuclease that cleaves pre-mRNAs, and a polymerase that adds a poly(A) tail onto the cleaved 3′ end. Several CPF subunits, including Fip1, contain intrinsically disordered regions (IDRs). IDRs within multiprotein complexes can be flexible, or can become ordered upon interaction with binding partners. Here, we show that yeast Fip1 anchors the poly(A) polymerase Pap1 onto CPF via an interaction with zinc finger 4 of another CPF subunit, Yth1. We also reconstitute a fully recombinant 850-kDa CPF. By incorporating selectively labeled Fip1 into recombinant CPF, we could study the dynamics of Fip1 within the megadalton complex using nuclear magnetic resonance (NMR) spectroscopy. This reveals that a Fip1 IDR that connects the Yth1- and Pap1-binding sites remains highly dynamic within CPF. Together, our data suggest that Fip1 dynamics within the 3′ end processing machinery are required to coordinate cleavage and polyadenylation.
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Affiliation(s)
| | - Conny W H Yu
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | | | - Xiao-Han Li
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Stefan M V Freund
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Lori A Passmore
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
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7
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Turtola M, Manav MC, Kumar A, Tudek A, Mroczek S, Krawczyk PS, Dziembowski A, Schmid M, Passmore LA, Casañal A, Jensen TH. Three-layered control of mRNA poly(A) tail synthesis in Saccharomyces cerevisiae. Genes Dev 2021; 35:1290-1303. [PMID: 34385261 PMCID: PMC8415320 DOI: 10.1101/gad.348634.121] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 07/15/2021] [Indexed: 12/13/2022]
Abstract
Biogenesis of most eukaryotic mRNAs involves the addition of an untemplated polyadenosine (pA) tail by the cleavage and polyadenylation machinery. The pA tail, and its exact length, impacts mRNA stability, nuclear export, and translation. To define how polyadenylation is controlled in S. cerevisiae, we have used an in vivo assay capable of assessing nuclear pA tail synthesis, analyzed tail length distributions by direct RNA sequencing, and reconstituted polyadenylation reactions with purified components. This revealed three control mechanisms for pA tail length. First, we found that the pA binding protein (PABP) Nab2p is the primary regulator of pA tail length. Second, when Nab2p is limiting, the nuclear pool of Pab1p, the second major PABP in yeast, controls the process. Third, when both PABPs are absent, the cleavage and polyadenylation factor (CPF) limits pA tail synthesis. Thus, Pab1p and CPF provide fail-safe mechanisms to a primary Nab2p-dependent pathway, thereby preventing uncontrolled polyadenylation and allowing mRNA export and translation.
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Affiliation(s)
- Matti Turtola
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark
| | - M Cemre Manav
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Ananthanarayanan Kumar
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Agnieszka Tudek
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland
| | - Seweryn Mroczek
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, 02-106 Warsaw, Poland
- International Institute of Molecular and Cell Biology in Warsaw, 02-109 Warsaw, Poland
| | - Paweł S Krawczyk
- International Institute of Molecular and Cell Biology in Warsaw, 02-109 Warsaw, Poland
| | - Andrzej Dziembowski
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, 02-106 Warsaw, Poland
- International Institute of Molecular and Cell Biology in Warsaw, 02-109 Warsaw, Poland
| | - Manfred Schmid
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark
| | - Lori A Passmore
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Ana Casañal
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Torben Heick Jensen
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark
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8
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Lee SY, Hung S, Esnault C, Pathak R, Johnson KR, Bankole O, Yamashita A, Zhang H, Levin HL. Dense Transposon Integration Reveals Essential Cleavage and Polyadenylation Factors Promote Heterochromatin Formation. Cell Rep 2021; 30:2686-2698.e8. [PMID: 32101745 PMCID: PMC9497450 DOI: 10.1016/j.celrep.2020.01.094] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 10/18/2019] [Accepted: 01/27/2020] [Indexed: 11/24/2022] Open
Abstract
Heterochromatin functions as a scaffold for factors responsible for gene
silencing and chromosome segregation. Heterochromatin can be assembled by
multiple pathways, including RNAi and RNA surveillance. We identified factors
that form heterochromatin using dense profiles of transposable element
integration in Schizosaccharomyces pombe. The candidates
include a large number of essential proteins such as four canonical mRNA
cleavage and polyadenylation factors. We find that Iss1, a subunit of the
poly(A) polymerase module, plays a role in forming heterochromatin in centromere
repeats that is independent of RNAi. Genome-wide maps reveal that Iss1
accumulates at genes regulated by RNA surveillance. Iss1 interacts with RNA
surveillance factors Mmi1 and Rrp6, and importantly, Iss1 contributes to RNA
elimination that forms heterochromatin at meiosis genes. Our profile of
transposable element integration supports the model that a network of mRNA
cleavage and polyadenylation factors coordinates RNA surveillance, including the
mechanism that forms heterochromatin at meiotic genes. Lee et al. use dense profiles of transposon integration to identify genes
important for the formation of heterochromatin. Among many candidates, Iss1 is a
canonical mRNA cleavage and polyadenylation factor found to be important for
heterochromatin at meiotic genes by recruiting the nuclear exosome.
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Affiliation(s)
- Si Young Lee
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Stevephen Hung
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Caroline Esnault
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Rakesh Pathak
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Kory R Johnson
- Bioinformatics Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Oluwadamilola Bankole
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Akira Yamashita
- National Institute for Basic Biology, Nishigonaka 38, Myodaiji, Okazaki, Aichi 444-8585, Japan
| | - Hongen Zhang
- Bioinformatics and Scientific Programming Core, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Henry L Levin
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
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9
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Abstract
In eukaryotes, the separation of translation from transcription by the nuclear envelope enables mRNA modifications such as capping, splicing, and polyadenylation. These modifications are mediated by a spectrum of ribonuclear proteins that associate with preRNA transcripts, coordinating the different steps and coupling them to nuclear export, ensuring that only mature transcripts reach the cytoplasmic translation machinery. Although the components of this machinery have been identified and considerable functional insight has been achieved, a number of questions remain outstanding about mRNA nuclear export and how it is integrated into the nuclear phase of the gene expression pathway. Nuclear export factors mediate mRNA transit through nuclear pores to the cytoplasm, after which these factors are removed from the mRNA, preventing transcripts from returning to the nucleus. However, as outlined in this review, several aspects of the mechanism by which transport factor binding and release are mediated remain unclear, as are the roles of accessory nuclear components in these processes. Moreover, the mechanisms by which completion of mRNA splicing and polyadenylation are recognized, together with how they are coordinated with nuclear export, also remain only partially characterized. One attractive hypothesis is that dissociating poly(A) polymerase from the cleavage and polyadenylation machinery could signal completion of mRNA maturation and thereby provide a mechanism for initiating nuclear export. The impressive array of genetic, molecular, cellular, and structural data that has been generated about these systems now provides many of the tools needed to define the precise mechanisms involved in these processes and how they are integrated.
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Affiliation(s)
- Murray Stewart
- From the MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, United Kingdom
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10
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Fasken MB, Corbett AH, Stewart M. Structure-function relationships in the Nab2 polyadenosine-RNA binding Zn finger protein family. Protein Sci 2019; 28:513-523. [PMID: 30578643 PMCID: PMC6371209 DOI: 10.1002/pro.3565] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 12/15/2018] [Accepted: 12/17/2018] [Indexed: 12/12/2022]
Abstract
The poly(A) RNA binding Zn finger ribonucleoprotein Nab2 functions to control the length of 3' poly(A) tails in Saccharomyces cerevisiae as well as contributing to the integration of the nuclear export of mature mRNA with preceding steps in the nuclear phase of the gene expression pathway. Nab2 is constructed from an N-terminal PWI-fold domain, followed by QQQP and RGG motifs and then seven CCCH Zn fingers. The nuclear pore-associated proteins Gfd1 and Mlp1 bind to opposite sides of the Nab2 N-terminal domain and function in the nuclear export of mRNA, whereas the Zn fingers, especially fingers 5-7, bind to A-rich regions of mature transcripts and function to regulate poly(A) tail length as well as mRNA compaction prior to nuclear export. Nab2 Zn fingers 5-7 have a defined spatial arrangement, with fingers 5 and 7 arranged on one side of the cluster and finger 6 on the other side. This spatial arrangement facilitates the dimerization of Nab2 when bound to adenine-rich RNAs and regulates both the termination of 3' polyadenylation and transcript compaction. Nab2 also functions to coordinate steps in the nuclear phase of the gene expression pathway, such as splicing and polyadenylation, with the generation of mature mRNA and its nuclear export. Nab2 orthologues in higher Eukaryotes have similar domain structures and play roles associated with the regulation of splicing and polyadenylation. Importantly, mutations in the gene encoding the human Nab2 orthologue ZC3H14 and cause intellectual disability.
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Affiliation(s)
- Milo B Fasken
- Department of Biology, Emory University, Atlanta, Georgia 30322
| | - Anita H Corbett
- Department of Biology, Emory University, Atlanta, Georgia 30322
| | - Murray Stewart
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge CB2 0QH, United Kingdom
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11
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Casañal A, Kumar A, Hill CH, Easter AD, Emsley P, Degliesposti G, Gordiyenko Y, Santhanam B, Wolf J, Wiederhold K, Dornan GL, Skehel M, Robinson CV, Passmore LA. Architecture of eukaryotic mRNA 3'-end processing machinery. Science 2017; 358:1056-1059. [PMID: 29074584 PMCID: PMC5788269 DOI: 10.1126/science.aao6535] [Citation(s) in RCA: 104] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 10/12/2017] [Indexed: 12/31/2022]
Abstract
Newly transcribed eukaryotic precursor messenger RNAs (pre-mRNAs) are processed at their 3' ends by the ~1-megadalton multiprotein cleavage and polyadenylation factor (CPF). CPF cleaves pre-mRNAs, adds a polyadenylate tail, and triggers transcription termination, but it is unclear how its various enzymes are coordinated and assembled. Here, we show that the nuclease, polymerase, and phosphatase activities of yeast CPF are organized into three modules. Using electron cryomicroscopy, we determined a 3.5-angstrom-resolution structure of the ~200-kilodalton polymerase module. This revealed four β propellers, in an assembly markedly similar to those of other protein complexes that bind nucleic acid. Combined with in vitro reconstitution experiments, our data show that the polymerase module brings together factors required for specific and efficient polyadenylation, to help coordinate mRNA 3'-end processing.
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Affiliation(s)
- Ana Casañal
- MRC Laboratory of Molecular Biology, Cambridge, UK
| | | | - Chris H Hill
- MRC Laboratory of Molecular Biology, Cambridge, UK
| | | | - Paul Emsley
- MRC Laboratory of Molecular Biology, Cambridge, UK
| | | | - Yuliya Gordiyenko
- MRC Laboratory of Molecular Biology, Cambridge, UK.,Chemistry Research Laboratory, University of Oxford, Oxford, UK
| | | | - Jana Wolf
- MRC Laboratory of Molecular Biology, Cambridge, UK
| | | | | | - Mark Skehel
- MRC Laboratory of Molecular Biology, Cambridge, UK
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12
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Jurado AR, Tan D, Jiao X, Kiledjian M, Tong L. Structure and function of pre-mRNA 5'-end capping quality control and 3'-end processing. Biochemistry 2014; 53:1882-98. [PMID: 24617759 PMCID: PMC3977584 DOI: 10.1021/bi401715v] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
Messenger RNA precursors (pre-mRNAs)
are produced as the nascent
transcripts of RNA polymerase II (Pol II) in eukaryotes and must undergo
extensive maturational processing, including 5′-end capping,
splicing, and 3′-end cleavage and polyadenylation. This review
will summarize the structural and functional information reported
over the past few years on the large machinery required for the 3′-end
processing of most pre-mRNAs, as well as the distinct machinery for
the 3′-end processing of replication-dependent histone pre-mRNAs,
which have provided great insights into the proteins and their subcomplexes
in these machineries. Structural and biochemical studies have also
led to the identification of a new class of enzymes (the DXO family
enzymes) with activity toward intermediates of the 5′-end capping
pathway. Functional studies demonstrate that these enzymes are part
of a novel quality surveillance mechanism for pre-mRNA 5′-end
capping. Incompletely capped pre-mRNAs are produced in yeast and human
cells, in contrast to the general belief in the field that capping
always proceeds to completion, and incomplete capping leads to defects
in splicing and 3′-end cleavage in human cells. The DXO family
enzymes are required for the detection and degradation of these defective
RNAs.
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Affiliation(s)
- Ashley R Jurado
- Department of Biological Sciences, Columbia University , New York, New York 10027, United States
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13
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Delineating the structural blueprint of the pre-mRNA 3'-end processing machinery. Mol Cell Biol 2014; 34:1894-910. [PMID: 24591651 DOI: 10.1128/mcb.00084-14] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Processing of mRNA precursors (pre-mRNAs) by polyadenylation is an essential step in gene expression. Polyadenylation consists of two steps, cleavage and poly(A) synthesis, and requires multiple cis elements in the pre-mRNA and a megadalton protein complex bearing the two essential enzymatic activities. While genetic and biochemical studies remain the major approaches in characterizing these factors, structural biology has emerged during the past decade to help understand the molecular assembly and mechanistic details of the process. With structural information about more proteins and higher-order complexes becoming available, we are coming closer to obtaining a structural blueprint of the polyadenylation machinery that explains both how this complex functions and how it is regulated and connected to other cellular processes.
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14
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Noël LA, Arts FA, Montano-Almendras CP, Cox L, Gielen O, Toffalini F, Marbehant CY, Cools J, Demoulin JB. The tyrosine phosphatase SHP2 is required for cell transformation by the receptor tyrosine kinase mutants FIP1L1-PDGFRα and PDGFRα D842V. Mol Oncol 2014; 8:728-40. [PMID: 24618081 DOI: 10.1016/j.molonc.2014.02.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Revised: 01/27/2014] [Accepted: 02/05/2014] [Indexed: 02/06/2023] Open
Abstract
Activated forms of the platelet derived growth factor receptor alpha (PDGFRα) have been described in various tumors, including FIP1L1-PDGFRα in patients with myeloproliferative diseases associated with hypereosinophilia and the PDGFRα(D842V) mutant in gastrointestinal stromal tumors and inflammatory fibroid polyps. To gain a better insight into the signal transduction mechanisms of PDGFRα oncogenes, we mutated twelve potentially phosphorylated tyrosine residues of FIP1L1-PDGFRα and identified three mutations that affected cell proliferation. In particular, mutation of tyrosine 720 in FIP1L1-PDGFRα or PDGFRα(D842V) inhibited cell growth and blocked ERK signaling in Ba/F3 cells. This mutation also decreased myeloproliferation in transplanted mice and the proliferation of human CD34(+) hematopoietic progenitors transduced with FIP1L1-PDGFRα. We showed that the non-receptor protein tyrosine phosphatase SHP2 bound directly to tyrosine 720 of FIP1L1-PDGFRα. SHP2 knock-down decreased proliferation of Ba/F3 cells transformed with FIP1L1-PDGFRα and PDGFRα(D842V) and affected ERK signaling, but not STAT5 phosphorylation. Remarkably, SHP2 was not essential for cell proliferation and ERK phosphorylation induced by the wild-type PDGF receptor in response to ligand stimulation, suggesting a shift in the function of SHP2 downstream of oncogenic receptors. In conclusion, our results indicate that SHP2 is required for cell transformation and ERK activation by mutant PDGF receptors.
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Affiliation(s)
- Laura A Noël
- de Duve Institute, Université catholique de Louvain, MEXP - UCL B1.74.05, Avenue Hippocrate 75, BE-1200 Brussels, Belgium.
| | - Florence A Arts
- de Duve Institute, Université catholique de Louvain, MEXP - UCL B1.74.05, Avenue Hippocrate 75, BE-1200 Brussels, Belgium.
| | - Carmen P Montano-Almendras
- de Duve Institute, Université catholique de Louvain, MEXP - UCL B1.74.05, Avenue Hippocrate 75, BE-1200 Brussels, Belgium.
| | - Luk Cox
- Center for The Biology of Disease, VIB, Herestraat 49, BE-3000 Leuven, Belgium; Center for Human Genetics, KU Leuven, Leuven, Belgium.
| | - Olga Gielen
- Center for The Biology of Disease, VIB, Herestraat 49, BE-3000 Leuven, Belgium; Center for Human Genetics, KU Leuven, Leuven, Belgium.
| | - Federica Toffalini
- de Duve Institute, Université catholique de Louvain, MEXP - UCL B1.74.05, Avenue Hippocrate 75, BE-1200 Brussels, Belgium.
| | - Catherine Y Marbehant
- de Duve Institute, Université catholique de Louvain, MEXP - UCL B1.74.05, Avenue Hippocrate 75, BE-1200 Brussels, Belgium.
| | - Jan Cools
- Center for The Biology of Disease, VIB, Herestraat 49, BE-3000 Leuven, Belgium; Center for Human Genetics, KU Leuven, Leuven, Belgium.
| | - Jean-Baptiste Demoulin
- de Duve Institute, Université catholique de Louvain, MEXP - UCL B1.74.05, Avenue Hippocrate 75, BE-1200 Brussels, Belgium.
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15
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Ezeokonkwo C, Ghazy MA, Zhelkovsky A, Yeh PC, Moore C. Novel interactions at the essential N-terminus of poly(A) polymerase that could regulate poly(A) addition in Saccharomyces cerevisiae. FEBS Lett 2012; 586:1173-8. [PMID: 22575652 DOI: 10.1016/j.febslet.2012.03.036] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Accepted: 03/14/2012] [Indexed: 10/28/2022]
Abstract
Addition of poly(A) to the 3' ends of cleaved pre-mRNA is essential for mRNA maturation and is catalyzed by Pap1 in yeast. We have previously shown that a non-viable Pap1 mutant lacking the first 18 amino acids is fully active for polyadenylation of oligoA, but defective for pre-mRNA polyadenylation, suggesting that interactions at the N-terminus are important for enzyme function in the processing complex. We have now identified proteins that interact specifically with this region. Cft1 and Pta1 are subunits of the cleavage/polyadenylation factor, in which Pap1 resides, and Nab6 and Sub1 are nucleic-acid binding proteins with known links to 3' end processing. Our results suggest a novel mechanism for controlling Pap1 activity, and possible models invoking these newly-discovered interactions are discussed.
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Affiliation(s)
- Chukwudi Ezeokonkwo
- Tufts School of Medicine and the Sackler Graduate School of Biomedical Sciences, Boston, MA 02111, USA
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16
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Ertekin A, Aramini JM, Rossi P, Leonard PG, Janjua H, Xiao R, Maglaqui M, Lee HW, Prestegard JH, Montelione GT. Human cyclin-dependent kinase 2-associated protein 1 (CDK2AP1) is dimeric in its disulfide-reduced state, with natively disordered N-terminal region. J Biol Chem 2012; 287:16541-9. [PMID: 22427660 DOI: 10.1074/jbc.m112.343863] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
CDK2AP1 (cyclin-dependent kinase 2-associated protein 1), corresponding to the gene doc-1 (deleted in oral cancer 1), is a tumor suppressor protein. The doc-1 gene is absent or down-regulated in hamster oral cancer cells and in many other cancer cell types. The ubiquitously expressed CDK2AP1 protein is the only known specific inhibitor of CDK2, making it an important component of cell cycle regulation during G(1)-to-S phase transition. Here, we report the solution structure of CDK2AP1 by combined methods of solution state NMR and amide hydrogen/deuterium exchange measurements with mass spectrometry. The homodimeric structure of CDK2AP1 includes an intrinsically disordered 60-residue N-terminal region and a four-helix bundle dimeric structure with reduced Cys-105 in the C-terminal region. The Cys-105 residues are, however, poised for disulfide bond formation. CDK2AP1 is phosphorylated at a conserved Ser-46 site in the N-terminal "intrinsically disordered" region by IκB kinase ε.
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Affiliation(s)
- Asli Ertekin
- Center for Advanced Biotechnology and Medicine and Northeast Structural Genomics Consortium, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, USA
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