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Graber JH, Hoskinson D, Liu H, Kaczmarek Michaels K, Benson PS, Maki NJ, Wilson CL, McGrath C, Puleo F, Pearson E, Kuehner JN, Moore C. Mutations in yeast Pcf11, a conserved protein essential for mRNA 3' end processing and transcription termination, elicit the Environmental Stress Response. Genetics 2024; 226:iyad199. [PMID: 37967370 PMCID: PMC10847720 DOI: 10.1093/genetics/iyad199] [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] [Received: 07/11/2023] [Revised: 10/28/2023] [Accepted: 10/31/2023] [Indexed: 11/17/2023] Open
Abstract
The Pcf11 protein is an essential subunit of the large complex that cleaves and polyadenylates eukaryotic mRNA precursor. It has also been functionally linked to gene-looping, termination of RNA Polymerase II (Pol II) transcripts, and mRNA export. We have examined a poorly characterized but conserved domain (amino acids 142-225) of the Saccharomyces cerevisiae Pcf11 and found that while it is not needed for mRNA 3' end processing or termination downstream of the poly(A) sites of protein-coding genes, its presence improves the interaction with Pol II and the use of transcription terminators near gene promoters. Analysis of genome-wide Pol II occupancy in cells with Pcf11 missing this region, as well as Pcf11 mutated in the Pol II CTD Interacting Domain, indicates that systematic changes in mRNA expression are mediated primarily at the level of transcription. Global expression analysis also shows that a general stress response, involving both activation and suppression of specific gene sets known to be regulated in response to a wide variety of stresses, is induced in the two pcf11 mutants, even though cells are grown in optimal conditions. The mutants also cause an unbalanced expression of cell wall-related genes that does not activate the Cell Wall Integrity pathway but is associated with strong caffeine sensitivity. Based on these findings, we propose that Pcf11 can modulate the expression level of specific functional groups of genes in ways that do not involve its well-characterized role in mRNA 3' end processing.
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Affiliation(s)
- Joel H Graber
- Mount Desert Island Biological Laboratory, Bar Harbor, ME 04609, USA
| | - Derick Hoskinson
- Department of Development, Molecular, and Chemical Biology and School of Graduate Biomedical Science, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Huiyun Liu
- Department of Development, Molecular, and Chemical Biology and School of Graduate Biomedical Science, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Katarzyna Kaczmarek Michaels
- Department of Development, Molecular, and Chemical Biology and School of Graduate Biomedical Science, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Peter S Benson
- Mount Desert Island Biological Laboratory, Bar Harbor, ME 04609, USA
| | - Nathaniel J Maki
- Mount Desert Island Biological Laboratory, Bar Harbor, ME 04609, USA
| | | | - Caleb McGrath
- Department of Biology, Emmanuel College, Boston, MA 02115, USA
| | - Franco Puleo
- Department of Development, Molecular, and Chemical Biology and School of Graduate Biomedical Science, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Erika Pearson
- Department of Development, Molecular, and Chemical Biology and School of Graduate Biomedical Science, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Jason N Kuehner
- Department of Biology, Emmanuel College, Boston, MA 02115, USA
| | - Claire Moore
- Department of Development, Molecular, and Chemical Biology and School of Graduate Biomedical Science, Tufts University School of Medicine, Boston, MA 02111, USA
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2
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Thore S, Raoelijaona F, Talenton V, Fribourg S, Mackereth CD. Molecular details of the CPSF73-CPSF100 C-terminal heterodimer and interaction with Symplekin. Open Biol 2023; 13:230221. [PMID: 37989222 PMCID: PMC10688271 DOI: 10.1098/rsob.230221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 09/27/2023] [Indexed: 11/23/2023] Open
Abstract
Eukaryotic pre-mRNA is processed by a large multiprotein complex to accurately cleave the 3' end, and to catalyse the addition of the poly(A) tail. Within this cleavage and polyadenylation specificity factor (CPSF) machinery, the CPSF73/CPSF3 endonuclease subunit directly contacts both CPSF100/CPSF2 and the scaffold protein Symplekin to form a subcomplex known as the core cleavage complex or mammalian cleavage factor. Here we have taken advantage of a stable CPSF73-CPSF100 minimal heterodimer from Encephalitozoon cuniculi to determine the solution structure formed by the first and second C-terminal domain (CTD1 and CTD2) of both proteins. We find a large number of contacts between both proteins in the complex, and notably in the region between CTD1 and CTD2. A similarity is also observed between CTD2 and the TATA-box binding protein (TBP) domains. Separately, we have determined the structure of the terminal CTD3 domain of CPSF73, which also belongs to the TBP domain family and is connected by a flexible linker to the rest of CPSF73. Biochemical assays demonstrate a key role for the CTD3 of CPSF73 in binding Symplekin, and structural models of the trimeric complex from other species allow for comparative analysis and support an overall conserved architecture.
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Affiliation(s)
- Stéphane Thore
- Inserm, CNRS, ARNA Laboratory, Univ. Bordeaux, U1212, UMR 5320, 33000 Bordeaux, France
| | - Finaritra Raoelijaona
- Inserm, CNRS, ARNA Laboratory, Univ. Bordeaux, U1212, UMR 5320, 33000 Bordeaux, France
| | - Vincent Talenton
- Inserm, CNRS, ARNA Laboratory, Univ. Bordeaux, Institut Européen de Chimie et Biologie, U1212, UMR 5320, 33600 Pessac, France
| | - Sébastien Fribourg
- Inserm, CNRS, ARNA Laboratory, Univ. Bordeaux, U1212, UMR 5320, 33000 Bordeaux, France
| | - Cameron D. Mackereth
- Inserm, CNRS, ARNA Laboratory, Univ. Bordeaux, Institut Européen de Chimie et Biologie, U1212, UMR 5320, 33600 Pessac, France
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3
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Alternative Polyadenylation Is a Novel Strategy for the Regulation of Gene Expression in Response to Stresses in Plants. Int J Mol Sci 2023; 24:ijms24054727. [PMID: 36902157 PMCID: PMC10003127 DOI: 10.3390/ijms24054727] [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: 12/27/2022] [Revised: 02/13/2023] [Accepted: 02/17/2023] [Indexed: 03/05/2023] Open
Abstract
Precursor message RNA requires processing to generate mature RNA. Cleavage and polyadenylation at the 3'-end in the maturation of mRNA is one of key processing steps in eukaryotes. The polyadenylation (poly(A)) tail of mRNA is an essential feature that is required to mediate its nuclear export, stability, translation efficiency, and subcellular localization. Most genes have at least two mRNA isoforms via alternative splicing (AS) or alternative polyadenylation (APA), which increases the diversity of transcriptome and proteome. However, most previous studies have focused on the role of alternative splicing on the regulation of gene expression. In this review, we summarize the recent advances concerning APA in the regulation of gene expression and in response to stresses in plants. We also discuss the mechanisms for the regulation of APA for plants in the adaptation to stress responses, and suggest that APA is a novel strategy for the adaptation to environmental changes and response to stresses in plants.
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4
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Schwich OD, Blümel N, Keller M, Wegener M, Setty ST, Brunstein ME, Poser I, Mozos IRDL, Suess B, Münch C, McNicoll F, Zarnack K, Müller-McNicoll M. SRSF3 and SRSF7 modulate 3'UTR length through suppression or activation of proximal polyadenylation sites and regulation of CFIm levels. Genome Biol 2021; 22:82. [PMID: 33706811 PMCID: PMC7948361 DOI: 10.1186/s13059-021-02298-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 02/11/2021] [Indexed: 12/23/2022] Open
Abstract
Background Alternative polyadenylation (APA) refers to the regulated selection of polyadenylation sites (PASs) in transcripts, which determines the length of their 3′ untranslated regions (3′UTRs). We have recently shown that SRSF3 and SRSF7, two closely related SR proteins, connect APA with mRNA export. The mechanism underlying APA regulation by SRSF3 and SRSF7 remained unknown. Results Here we combine iCLIP and 3′-end sequencing and find that SRSF3 and SRSF7 bind upstream of proximal PASs (pPASs), but they exert opposite effects on 3′UTR length. SRSF7 enhances pPAS usage in a concentration-dependent but splicing-independent manner by recruiting the cleavage factor FIP1, generating short 3′UTRs. Protein domains unique to SRSF7, which are absent from SRSF3, contribute to FIP1 recruitment. In contrast, SRSF3 promotes distal PAS (dPAS) usage and hence long 3′UTRs directly by counteracting SRSF7, but also indirectly by maintaining high levels of cleavage factor Im (CFIm) via alternative splicing. Upon SRSF3 depletion, CFIm levels decrease and 3′UTRs are shortened. The indirect SRSF3 targets are particularly sensitive to low CFIm levels, because here CFIm serves a dual function; it enhances dPAS and inhibits pPAS usage by binding immediately downstream and assembling unproductive cleavage complexes, which together promotes long 3′UTRs. Conclusions We demonstrate that SRSF3 and SRSF7 are direct modulators of pPAS usage and show how small differences in the domain architecture of SR proteins can confer opposite effects on pPAS regulation. Supplementary Information The online version contains supplementary material available at 10.1186/s13059-021-02298-y.
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Affiliation(s)
- Oliver Daniel Schwich
- Institute for Molecular Bio Science, Goethe University Frankfurt, Max-von-Laue-Str. 13, 60438, Frankfurt, Germany.,Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Max-von-Laue-Str. 15, 60438, Frankfurt, Germany
| | - Nicole Blümel
- Institute for Molecular Bio Science, Goethe University Frankfurt, Max-von-Laue-Str. 13, 60438, Frankfurt, Germany
| | - Mario Keller
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Max-von-Laue-Str. 15, 60438, Frankfurt, Germany.,Faculty of Biological Sciences, Goethe University Frankfurt, 60438, Frankfurt am Main, Germany
| | - Marius Wegener
- Institute for Molecular Bio Science, Goethe University Frankfurt, Max-von-Laue-Str. 13, 60438, Frankfurt, Germany.,Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Max-von-Laue-Str. 15, 60438, Frankfurt, Germany
| | - Samarth Thonta Setty
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Max-von-Laue-Str. 15, 60438, Frankfurt, Germany
| | - Melinda Elaine Brunstein
- Institute of Biochemistry II, Medical School, Goethe University Frankfurt, Sandhofstr. 2-4, 60528, Frankfurt am Main, Germany
| | - Ina Poser
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstr. 108, 01307, Dresden, Germany
| | | | - Beatrix Suess
- Department of Biology, Technical University Darmstadt, Schnittspahnstr. 10, 64287, Darmstadt, Germany
| | - Christian Münch
- Institute of Biochemistry II, Medical School, Goethe University Frankfurt, Sandhofstr. 2-4, 60528, Frankfurt am Main, Germany
| | - François McNicoll
- Institute for Molecular Bio Science, Goethe University Frankfurt, Max-von-Laue-Str. 13, 60438, Frankfurt, Germany
| | - Kathi Zarnack
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Max-von-Laue-Str. 15, 60438, Frankfurt, Germany. .,Faculty of Biological Sciences, Goethe University Frankfurt, 60438, Frankfurt am Main, Germany.
| | - Michaela Müller-McNicoll
- Institute for Molecular Bio Science, Goethe University Frankfurt, Max-von-Laue-Str. 13, 60438, Frankfurt, Germany.
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5
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Al-Husini N, Medler S, Ansari A. Crosstalk of promoter and terminator during RNA polymerase II transcription cycle. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2020; 1863:194657. [PMID: 33246184 DOI: 10.1016/j.bbagrm.2020.194657] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 11/16/2020] [Accepted: 11/17/2020] [Indexed: 12/16/2022]
Abstract
The transcription cycle of RNAPII is comprised of three consecutive steps; initiation, elongation and termination. It has been assumed that the initiation and termination steps occur in spatial isolation, essentially as independent events. A growing body of evidence, however, has challenged this dogma. First, factors involved in initiation and termination exhibit both a genetic and a physical interaction during transcription. Second, the initiation and termination factors have been found to occupy both ends of a transcribing gene. Third, physical interaction of initiation and termination factors occupying distal ends of a gene sometime results in the entire terminator region of a genes looping back and contact its cognate promoter, thereby forming a looped gene architecture during transcription. A logical interpretation of these findings is that the initiation and termination steps of transcription do not occur in isolation. There is extensive communication of factors occupying promoter and terminator ends of a gene during transcription cycle. This review entails a discussion of the promoter-terminator crosstalk and its implication in the context of transcription.
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Affiliation(s)
- Nadra Al-Husini
- Department of Biological Science, Wayne State University, Detroit, MI, United States of America
| | - Scott Medler
- Department of Biological Science, Wayne State University, Detroit, MI, United States of America
| | - Athar Ansari
- Department of Biological Science, Wayne State University, Detroit, MI, United States of America.
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6
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Lee SD, Liu HY, Graber JH, Heller-Trulli D, Kaczmarek Michaels K, Cerezo JF, Moore CL. Regulation of the Ysh1 endonuclease of the mRNA cleavage/polyadenylation complex by ubiquitin-mediated degradation. RNA Biol 2020; 17:689-702. [PMID: 32009536 PMCID: PMC7237158 DOI: 10.1080/15476286.2020.1724717] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Revised: 01/25/2020] [Accepted: 01/27/2020] [Indexed: 12/12/2022] Open
Abstract
Mutation of the essential yeast protein Ipa1 has previously been demonstrated to cause defects in pre-mRNA 3' end processing and growth, but the mechanism underlying these defects was not clear. In this study, we show that the ipa1-1 mutation causes a striking depletion of Ysh1, the evolutionarily conserved endonuclease subunit of the 19-subunit mRNA Cleavage/Polyadenylation (C/P) complex, but does not decrease other C/P subunits. YSH1 overexpression rescues both the growth and 3' end processing defects of the ipa1-1 mutant. YSH1 mRNA level is unchanged in ipa1-1 cells, and proteasome inactivation prevents Ysh1 loss and causes accumulation of ubiquitinated Ysh1. Ysh1 ubiquitination is mediated by the Ubc4 ubiquitin-conjugating enzyme and Mpe1, which in addition to its function in C/P, is also a RING ubiquitin ligase. In summary, Ipa1 affects mRNA processing by controlling the availability of the C/P endonuclease and may represent a regulatory mechanism that could be rapidly deployed to facilitate reprogramming of cellular responses.
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Affiliation(s)
- Susan D. Lee
- Department of Developmental, Molecular, and Chemical Biology and Tufts School of Graduate Biomedical Science, Tufts University School of Medicine, Boston, MA, USA
| | - Hui-Yun Liu
- Department of Developmental, Molecular, and Chemical Biology and Tufts School of Graduate Biomedical Science, Tufts University School of Medicine, Boston, MA, USA
| | - Joel H. Graber
- Computational Biology and Bioinformatics Core, Mount Desert Island Biological Laboratory, Bar Harbor, ME, USA
| | - Daniel Heller-Trulli
- Department of Developmental, Molecular, and Chemical Biology and Tufts School of Graduate Biomedical Science, Tufts University School of Medicine, Boston, MA, USA
| | - Katarzyna Kaczmarek Michaels
- Department of Developmental, Molecular, and Chemical Biology and Tufts School of Graduate Biomedical Science, Tufts University School of Medicine, Boston, MA, USA
| | | | - Claire L. Moore
- Department of Developmental, Molecular, and Chemical Biology and Tufts School of Graduate Biomedical Science, Tufts University School of Medicine, Boston, MA, USA
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7
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Ipa1 Is an RNA Polymerase II Elongation Factor that Facilitates Termination by Maintaining Levels of the Poly(A) Site Endonuclease Ysh1. Cell Rep 2020; 26:1919-1933.e5. [PMID: 30759400 PMCID: PMC7236606 DOI: 10.1016/j.celrep.2019.01.051] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 12/05/2018] [Accepted: 01/15/2019] [Indexed: 02/08/2023] Open
Abstract
The yeast protein Ipa1 was recently discovered to interact with the Ysh1
endonuclease of the prem-RNA cleavage and polyadenylation (C/P) machinery, and
Ipa1 mutation impairs 3′end processing. We report that Ipa1 globally
promotes proper transcription termination and poly(A) site selection, but with
variable effects on genes depending upon the specific configurations of
polyadenylation signals. Our findings suggest that the role of Ipa1 in
termination is mediated through interaction with Ysh1, since Ipa1 mutation leads
to decrease in Ysh1 and poor recruitment of the C/P complex to a transcribed
gene. The Ipa1 association with transcriptionally active chromatin resembles
that of elongation factors, and the mutant shows defective Pol II elongation
kinetics in vivo. Ysh1 overexpression in the Ipa1 mutant
rescues the termination defect, but not the mutant’s sensitivity to
6-azauracil, an indicator of defective elongation. Our findings support a model
in which an Ipa1/Ysh1 complex helps coordinate transcription elongation and
3′ end processing. The essential, uncharacterized Ipa1 protein was recently discovered to
interact with the Ysh1 endonuclease of the pre-mRNA cleavage and polyadenylation
machinery. Pearson et al. propose that the Ipa1/Ysh1 interaction provides the
cell with a means to coordinate and regulate transcription elongation with
3′ end processing in accordance with the cell’s needs.
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8
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Hill CH, Boreikaitė V, Kumar A, Casañal A, Kubík P, Degliesposti G, Maslen S, Mariani A, von Loeffelholz O, Girbig M, Skehel M, Passmore LA. Activation of the Endonuclease that Defines mRNA 3' Ends Requires Incorporation into an 8-Subunit Core Cleavage and Polyadenylation Factor Complex. Mol Cell 2019; 73:1217-1231.e11. [PMID: 30737185 PMCID: PMC6436931 DOI: 10.1016/j.molcel.2018.12.023] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 11/02/2018] [Accepted: 12/21/2018] [Indexed: 01/19/2023]
Abstract
Cleavage and polyadenylation factor (CPF/CPSF) is a multi-protein complex essential for formation of eukaryotic mRNA 3' ends. CPF cleaves pre-mRNAs at a specific site and adds a poly(A) tail. The cleavage reaction defines the 3' end of the mature mRNA, and thus the activity of the endonuclease is highly regulated. Here, we show that reconstitution of specific pre-mRNA cleavage with recombinant yeast proteins requires incorporation of the Ysh1 endonuclease into an eight-subunit "CPFcore" complex. Cleavage also requires the accessory cleavage factors IA and IB, which bind substrate pre-mRNAs and CPF, likely facilitating assembly of an active complex. Using X-ray crystallography, electron microscopy, and mass spectrometry, we determine the structure of Ysh1 bound to Mpe1 and the arrangement of subunits within CPFcore. Together, our data suggest that the active mRNA 3' end processing machinery is a dynamic assembly that is licensed to cleave only when all protein factors come together at the polyadenylation site.
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Affiliation(s)
- Chris H Hill
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | | | | | - Ana Casañal
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - Peter Kubík
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | | | - Sarah Maslen
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | | | - Ottilie von Loeffelholz
- Centre for Integrative Biology, Department of Integrated Structural Biology, Institute of Genetics and of Molecular and Cellular Biology, Illkirch, Université de Strasbourg, Strasbourg, France; Centre National de la Recherche Scientifique UMR 7104, Illkirch, Université de Strasbourg, Strasbourg, France; INSERM U964, Illkirch, Université de Strasbourg, Strasbourg, France
| | - Mathias Girbig
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - Mark Skehel
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
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9
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McGinty RJ, Puleo F, Aksenova AY, Hisey JA, Shishkin AA, Pearson EL, Wang ET, Housman DE, Moore C, Mirkin SM. A Defective mRNA Cleavage and Polyadenylation Complex Facilitates Expansions of Transcribed (GAA) n Repeats Associated with Friedreich's Ataxia. Cell Rep 2018; 20:2490-2500. [PMID: 28877480 DOI: 10.1016/j.celrep.2017.08.051] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 07/19/2017] [Accepted: 08/15/2017] [Indexed: 02/03/2023] Open
Abstract
Expansions of microsatellite repeats are responsible for numerous hereditary diseases in humans, including myotonic dystrophy and Friedreich's ataxia. Whereas the length of an expandable repeat is the main factor determining disease inheritance, recent data point to genomic trans modifiers that can impact the likelihood of expansions and disease progression. Detection of these modifiers may lead to understanding and treating repeat expansion diseases. Here, we describe a method for the rapid, genome-wide identification of trans modifiers for repeat expansion in a yeast experimental system. Using this method, we found that missense mutations in the endoribonuclease subunit (Ysh1) of the mRNA cleavage and polyadenylation complex dramatically increase the rate of (GAA)n repeat expansions but only when they are actively transcribed. These expansions correlate with slower transcription elongation caused by the ysh1 mutation. These results reveal an interplay between RNA processing and repeat-mediated genome instability, confirming the validity of our approach.
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Affiliation(s)
- Ryan J McGinty
- Department of Biology, Tufts University, Medford, MA 02421, USA
| | - Franco Puleo
- Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Anna Y Aksenova
- Department of Biology, Tufts University, Medford, MA 02421, USA; Laboratory of Amyloid Biology, St. Petersburg State University, St. Petersburg 199034, Russia
| | - Julia A Hisey
- Department of Biology, Tufts University, Medford, MA 02421, USA
| | - Alexander A Shishkin
- Department of Biology, Tufts University, Medford, MA 02421, USA; The Broad Institute of MIT and Harvard, Cambridge, MA 02139, USA
| | - Erika L Pearson
- Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Eric T Wang
- The David H. Koch Institute for Integrative Cancer Research at MIT, Cambridge, MA 02139, USA; Center for Neurogenetics, University of Florida, Gainesville, FL 32610, USA
| | - David E Housman
- The David H. Koch Institute for Integrative Cancer Research at MIT, Cambridge, MA 02139, USA
| | - Claire Moore
- Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Sergei M Mirkin
- Department of Biology, Tufts University, Medford, MA 02421, USA.
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10
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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: 103] [Impact Index Per Article: 14.7] [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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11
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Barros MH, Tzagoloff A. Aep3p-dependent translation of yeast mitochondrial ATP8. Mol Biol Cell 2017; 28:1426-1434. [PMID: 28404747 PMCID: PMC5449143 DOI: 10.1091/mbc.e16-11-0775] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 03/29/2017] [Accepted: 04/04/2017] [Indexed: 12/14/2022] Open
Abstract
Yeast Aep3p, previously reported to stabilize mitochondrial ATP8 mRNA, also activates its translation. Temperature-sensitive aep3 mutants are specifically defective in translating ATP8 at the restrictive temperature. The respiratory deficiency of aep3 mutants is rescued by expression in the cytoplasm of allotopic ATP8. Translation of mitochondrial gene products in Saccharomyces cerevisiae depends on mRNA-specific activators that bind to the 5’ untranslated regions and promote translation on mitochondrial ribosomes. Here we find that Aep3p, previously shown to stabilize the bicistronic ATP8-ATP6 mRNA and facilitate initiation of translation from unformylated methionine, also activates specifically translation of ATP8. This is supported by several lines of evidence. Temperature-sensitive aep3 mutants are selectively blocked in incorporating [35S]methionine into Atp8p at nonpermissive but not at the permissive temperature. This phenotype is not a consequence of defective transcription or processing of the pre-mRNA. Neither is it explained by turnover of Aep3p, as evidenced by the failure of aep3 mutants to express a recoded ARG8m when this normally nuclear gene is substituted for ATP8 in mitochondrial DNA. Finally, translational of ATP8 mRNA in aep3 mutants is partially rescued by recoded allotopic ATP8 (nATP8) in a high-expression plasmid or in a CEN plasmid in the presence of recessive mutations in genes involved in stability and polyadenylation of RNA.
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Affiliation(s)
- Mario H Barros
- Departamento de Microbiologia, Universidade de Sao Paulo, Sao Paulo 05508-900, Brazil
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12
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Costanzo M, VanderSluis B, Koch EN, Baryshnikova A, Pons C, Tan G, Wang W, Usaj M, Hanchard J, Lee SD, Pelechano V, Styles EB, Billmann M, van Leeuwen J, van Dyk N, Lin ZY, Kuzmin E, Nelson J, Piotrowski JS, Srikumar T, Bahr S, Chen Y, Deshpande R, Kurat CF, Li SC, Li Z, Usaj MM, Okada H, Pascoe N, San Luis BJ, Sharifpoor S, Shuteriqi E, Simpkins SW, Snider J, Suresh HG, Tan Y, Zhu H, Malod-Dognin N, Janjic V, Przulj N, Troyanskaya OG, Stagljar I, Xia T, Ohya Y, Gingras AC, Raught B, Boutros M, Steinmetz LM, Moore CL, Rosebrock AP, Caudy AA, Myers CL, Andrews B, Boone C. A global genetic interaction network maps a wiring diagram of cellular function. Science 2017; 353:353/6306/aaf1420. [PMID: 27708008 DOI: 10.1126/science.aaf1420] [Citation(s) in RCA: 759] [Impact Index Per Article: 108.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
We generated a global genetic interaction network for Saccharomyces cerevisiae, constructing more than 23 million double mutants, identifying about 550,000 negative and about 350,000 positive genetic interactions. This comprehensive network maps genetic interactions for essential gene pairs, highlighting essential genes as densely connected hubs. Genetic interaction profiles enabled assembly of a hierarchical model of cell function, including modules corresponding to protein complexes and pathways, biological processes, and cellular compartments. Negative interactions connected functionally related genes, mapped core bioprocesses, and identified pleiotropic genes, whereas positive interactions often mapped general regulatory connections among gene pairs, rather than shared functionality. The global network illustrates how coherent sets of genetic interactions connect protein complex and pathway modules to map a functional wiring diagram of the cell.
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Affiliation(s)
- Michael Costanzo
- The Donnelly Centre, University of Toronto, 160 College Street, Toronto ON, Canada M5S 3E1
| | - Benjamin VanderSluis
- Department of Computer Science and Engineering, University of Minnesota-Twin Cities, 200 Union Street, Minneapolis, MN 55455, USA. Simons Center for Data Analysis, Simons Foundation, 160 Fifth Avenue, New York, NY 10010, USA
| | - Elizabeth N Koch
- Department of Computer Science and Engineering, University of Minnesota-Twin Cities, 200 Union Street, Minneapolis, MN 55455, USA
| | - Anastasia Baryshnikova
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
| | - Carles Pons
- Department of Computer Science and Engineering, University of Minnesota-Twin Cities, 200 Union Street, Minneapolis, MN 55455, USA
| | - Guihong Tan
- The Donnelly Centre, University of Toronto, 160 College Street, Toronto ON, Canada M5S 3E1
| | - Wen Wang
- Department of Computer Science and Engineering, University of Minnesota-Twin Cities, 200 Union Street, Minneapolis, MN 55455, USA
| | - Matej Usaj
- The Donnelly Centre, University of Toronto, 160 College Street, Toronto ON, Canada M5S 3E1
| | - Julia Hanchard
- The Donnelly Centre, University of Toronto, 160 College Street, Toronto ON, Canada M5S 3E1. Department of Molecular Genetics, University of Toronto, 160 College Street, Toronto ON, Canada M5S 3E1
| | - Susan D Lee
- Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Vicent Pelechano
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, 69117 Heidelberg, Germany
| | - Erin B Styles
- The Donnelly Centre, University of Toronto, 160 College Street, Toronto ON, Canada M5S 3E1. Department of Molecular Genetics, University of Toronto, 160 College Street, Toronto ON, Canada M5S 3E1
| | - Maximilian Billmann
- Division of Signaling and Functional Genomics, German Cancer Research Center (DKFZ) and Heidelberg University, Heidelberg, Germany
| | - Jolanda van Leeuwen
- The Donnelly Centre, University of Toronto, 160 College Street, Toronto ON, Canada M5S 3E1
| | - Nydia van Dyk
- The Donnelly Centre, University of Toronto, 160 College Street, Toronto ON, Canada M5S 3E1
| | - Zhen-Yuan Lin
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto ON, Canada
| | - Elena Kuzmin
- The Donnelly Centre, University of Toronto, 160 College Street, Toronto ON, Canada M5S 3E1. Department of Molecular Genetics, University of Toronto, 160 College Street, Toronto ON, Canada M5S 3E1
| | - Justin Nelson
- Department of Computer Science and Engineering, University of Minnesota-Twin Cities, 200 Union Street, Minneapolis, MN 55455, USA. Program in Biomedical Informatics and Computational Biology, University of Minnesota-Twin Cities, 200 Union Street, Minneapolis, MN 55455, USA
| | - Jeff S Piotrowski
- The Donnelly Centre, University of Toronto, 160 College Street, Toronto ON, Canada M5S 3E1. Chemical Genomics Research Group, RIKEN Center for Sustainable Resource Sciences (CSRS), Saitama, Japan
| | - Tharan Srikumar
- Princess Margaret Cancer Centre, University Health Network and Department of Medical Biophysics, University of Toronto, Toronto ON, Canada
| | - Sondra Bahr
- The Donnelly Centre, University of Toronto, 160 College Street, Toronto ON, Canada M5S 3E1
| | - Yiqun Chen
- The Donnelly Centre, University of Toronto, 160 College Street, Toronto ON, Canada M5S 3E1
| | - Raamesh Deshpande
- Department of Computer Science and Engineering, University of Minnesota-Twin Cities, 200 Union Street, Minneapolis, MN 55455, USA
| | - Christoph F Kurat
- The Donnelly Centre, University of Toronto, 160 College Street, Toronto ON, Canada M5S 3E1
| | - Sheena C Li
- The Donnelly Centre, University of Toronto, 160 College Street, Toronto ON, Canada M5S 3E1. Chemical Genomics Research Group, RIKEN Center for Sustainable Resource Sciences (CSRS), Saitama, Japan
| | - Zhijian Li
- The Donnelly Centre, University of Toronto, 160 College Street, Toronto ON, Canada M5S 3E1
| | - Mojca Mattiazzi Usaj
- The Donnelly Centre, University of Toronto, 160 College Street, Toronto ON, Canada M5S 3E1
| | - Hiroki Okada
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, University of Tokyo, Kashiwa, Chiba, Japan 277-8561
| | - Natasha Pascoe
- The Donnelly Centre, University of Toronto, 160 College Street, Toronto ON, Canada M5S 3E1. Department of Molecular Genetics, University of Toronto, 160 College Street, Toronto ON, Canada M5S 3E1
| | - Bryan-Joseph San Luis
- The Donnelly Centre, University of Toronto, 160 College Street, Toronto ON, Canada M5S 3E1
| | - Sara Sharifpoor
- The Donnelly Centre, University of Toronto, 160 College Street, Toronto ON, Canada M5S 3E1
| | - Emira Shuteriqi
- The Donnelly Centre, University of Toronto, 160 College Street, Toronto ON, Canada M5S 3E1
| | - Scott W Simpkins
- Department of Computer Science and Engineering, University of Minnesota-Twin Cities, 200 Union Street, Minneapolis, MN 55455, USA. Program in Biomedical Informatics and Computational Biology, University of Minnesota-Twin Cities, 200 Union Street, Minneapolis, MN 55455, USA
| | - Jamie Snider
- The Donnelly Centre, University of Toronto, 160 College Street, Toronto ON, Canada M5S 3E1
| | - Harsha Garadi Suresh
- The Donnelly Centre, University of Toronto, 160 College Street, Toronto ON, Canada M5S 3E1
| | - Yizhao Tan
- The Donnelly Centre, University of Toronto, 160 College Street, Toronto ON, Canada M5S 3E1
| | - Hongwei Zhu
- The Donnelly Centre, University of Toronto, 160 College Street, Toronto ON, Canada M5S 3E1
| | - Noel Malod-Dognin
- Computer Science Deptartment, University College London, London WC1E 6BT, UK
| | - Vuk Janjic
- Department of Computing, Imperial College London, UK
| | - Natasa Przulj
- Computer Science Deptartment, University College London, London WC1E 6BT, UK. School of Computing (RAF), Union University, Belgrade, Serbia
| | - Olga G Troyanskaya
- Simons Center for Data Analysis, Simons Foundation, 160 Fifth Avenue, New York, NY 10010, USA. Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
| | - Igor Stagljar
- The Donnelly Centre, University of Toronto, 160 College Street, Toronto ON, Canada M5S 3E1. Department of Molecular Genetics, University of Toronto, 160 College Street, Toronto ON, Canada M5S 3E1. Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Tian Xia
- Department of Computer Science and Engineering, University of Minnesota-Twin Cities, 200 Union Street, Minneapolis, MN 55455, USA. School of Electronic Information and Communications, Huazhong University of Science and Technology, Wuhan, China, 430074
| | - Yoshikazu Ohya
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, University of Tokyo, Kashiwa, Chiba, Japan 277-8561
| | - Anne-Claude Gingras
- Department of Molecular Genetics, University of Toronto, 160 College Street, Toronto ON, Canada M5S 3E1. Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto ON, Canada
| | - Brian Raught
- Princess Margaret Cancer Centre, University Health Network and Department of Medical Biophysics, University of Toronto, Toronto ON, Canada
| | - Michael Boutros
- Division of Signaling and Functional Genomics, German Cancer Research Center (DKFZ) and Heidelberg University, Heidelberg, Germany
| | - Lars M Steinmetz
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, 69117 Heidelberg, Germany. Department of Genetics, School of Medicine and Stanford Genome Technology Center Stanford University, Palo Alto, CA 94304, USA
| | - Claire L Moore
- Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Adam P Rosebrock
- The Donnelly Centre, University of Toronto, 160 College Street, Toronto ON, Canada M5S 3E1. Department of Molecular Genetics, University of Toronto, 160 College Street, Toronto ON, Canada M5S 3E1
| | - Amy A Caudy
- The Donnelly Centre, University of Toronto, 160 College Street, Toronto ON, Canada M5S 3E1. Department of Molecular Genetics, University of Toronto, 160 College Street, Toronto ON, Canada M5S 3E1
| | - Chad L Myers
- Department of Computer Science and Engineering, University of Minnesota-Twin Cities, 200 Union Street, Minneapolis, MN 55455, USA. Program in Biomedical Informatics and Computational Biology, University of Minnesota-Twin Cities, 200 Union Street, Minneapolis, MN 55455, USA.
| | - Brenda Andrews
- The Donnelly Centre, University of Toronto, 160 College Street, Toronto ON, Canada M5S 3E1. Department of Molecular Genetics, University of Toronto, 160 College Street, Toronto ON, Canada M5S 3E1.
| | - Charles Boone
- The Donnelly Centre, University of Toronto, 160 College Street, Toronto ON, Canada M5S 3E1. Department of Molecular Genetics, University of Toronto, 160 College Street, Toronto ON, Canada M5S 3E1. Chemical Genomics Research Group, RIKEN Center for Sustainable Resource Sciences (CSRS), Saitama, Japan.
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Yang F, Hsu P, Lee SD, Yang W, Hoskinson D, Xu W, Moore C, Varani G. The C terminus of Pcf11 forms a novel zinc-finger structure that plays an essential role in mRNA 3'-end processing. RNA (NEW YORK, N.Y.) 2017; 23:98-107. [PMID: 27780845 PMCID: PMC5159653 DOI: 10.1261/rna.058354.116] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 10/16/2016] [Indexed: 05/22/2023]
Abstract
3'-End processing of pre-mRNAs prior to packaging and export to the cytoplasm of the mature transcript is a highly regulated process executed by several tens of protein factors that recognize poorly conserved RNA signals. Among them is Pcf11, a highly conserved, multidomain protein that links transcriptional elongation, 3'-end processing, and transcription termination. Here we report the structure and biochemical function of Pcf11's C-terminal domain, which is conserved from yeast to humans. We identify a novel zinc-finger fold, resembling a trillium flower. Structural, biochemical, and genetic analyses reveal a highly conserved surface that plays a critical role in both cleavage and polyadenylation. These findings provide further insight into this important protein and its multiple functional roles during cotranscriptional RNA processing.
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Affiliation(s)
- Fan Yang
- Department of Chemistry, University of Washington, Seattle, Washington 98195, USA
| | - Peter Hsu
- Department of Chemistry, University of Washington, Seattle, Washington 98195, USA
| | - Susan D Lee
- Department of Developmental, Molecular, and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
| | - Wen Yang
- Department of Chemistry, University of Washington, Seattle, Washington 98195, USA
| | - Derick Hoskinson
- Department of Developmental, Molecular, and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
| | - Weihao Xu
- Department of Chemistry, University of Washington, Seattle, Washington 98195, USA
| | - Claire Moore
- Department of Developmental, Molecular, and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
| | - Gabriele Varani
- Department of Chemistry, University of Washington, Seattle, Washington 98195, USA
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14
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Blair LP, Liu Z, Labitigan RLD, Wu L, Zheng D, Xia Z, Pearson EL, Nazeer FI, Cao J, Lang SM, Rines RJ, Mackintosh SG, Moore CL, Li W, Tian B, Tackett AJ, Yan Q. KDM5 lysine demethylases are involved in maintenance of 3'UTR length. SCIENCE ADVANCES 2016; 2:e1501662. [PMID: 28138513 PMCID: PMC5262454 DOI: 10.1126/sciadv.1501662] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 10/20/2016] [Indexed: 06/06/2023]
Abstract
The complexity by which cells regulate gene and protein expression is multifaceted and intricate. Regulation of 3' untranslated region (UTR) processing of mRNA has been shown to play a critical role in development and disease. However, the process by which cells select alternative mRNA forms is not well understood. We discovered that the Saccharomyces cerevisiae lysine demethylase, Jhd2 (also known as KDM5), recruits 3'UTR processing machinery and promotes alteration of 3'UTR length for some genes in a demethylase-dependent manner. Interaction of Jhd2 with both chromatin and RNA suggests that Jhd2 affects selection of polyadenylation sites through a transcription-coupled mechanism. Furthermore, its mammalian homolog KDM5B (also known as JARID1B or PLU1), but not KDM5A (also known as JARID1A or RBP2), promotes shortening of CCND1 transcript in breast cancer cells. Consistent with these results, KDM5B expression correlates with shortened CCND1 in human breast tumor tissues. In contrast, both KDM5A and KDM5B are involved in the lengthening of DICER1. Our findings suggest both a novel role for this family of demethylases and a novel targetable mechanism for 3'UTR processing.
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Affiliation(s)
- Lauren P. Blair
- Department of Pathology, Yale School of Medicine, New Haven, CT 06520, USA
| | - Zongzhi Liu
- Department of Pathology, Yale School of Medicine, New Haven, CT 06520, USA
| | | | - Lizhen Wu
- Department of Pathology, Yale School of Medicine, New Haven, CT 06520, USA
| | - Dinghai Zheng
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers New Jersey Medical School, Newark, NJ 07103, USA
| | - Zheng Xia
- Division of Biostatistics, Dan L Duncan Comprehensive Cancer Center and Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Erica L. Pearson
- Department of Developmental, Molecular, and Chemical Biology, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Fathima I. Nazeer
- Department of Developmental, Molecular, and Chemical Biology, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Jian Cao
- Department of Pathology, Yale School of Medicine, New Haven, CT 06520, USA
| | - Sabine M. Lang
- Department of Pathology, Yale School of Medicine, New Haven, CT 06520, USA
| | - Rachel J. Rines
- Department of Pathology, Yale School of Medicine, New Haven, CT 06520, USA
| | - Samuel G. Mackintosh
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72032, USA
| | - Claire L. Moore
- Department of Developmental, Molecular, and Chemical Biology, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Wei Li
- Division of Biostatistics, Dan L Duncan Comprehensive Cancer Center and Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Bin Tian
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers New Jersey Medical School, Newark, NJ 07103, USA
| | - Alan J. Tackett
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72032, USA
| | - Qin Yan
- Department of Pathology, Yale School of Medicine, New Haven, CT 06520, USA
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15
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Paul B, Montpetit B. Altered RNA processing and export lead to retention of mRNAs near transcription sites and nuclear pore complexes or within the nucleolus. Mol Biol Cell 2016; 27:2742-56. [PMID: 27385342 PMCID: PMC5007094 DOI: 10.1091/mbc.e16-04-0244] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 06/29/2016] [Indexed: 01/17/2023] Open
Abstract
In a screen of >1000 essential gene mutants in Saccharomyces cerevisiae, 26 mutants are found that directly or indirectly affect mRNA processing and/or mRNA export. Single-molecule FISH data show that the majority of these mutants retain mRNAs at discrete locations within the nucleus, which include the nucleolus. Many protein factors are required for mRNA biogenesis and nuclear export, which are central to the eukaryotic gene expression program. It is unclear, however, whether all factors have been identified. Here we report on a screen of >1000 essential gene mutants in Saccharomyces cerevisiae for defects in mRNA processing and export, identifying 26 mutants with defects in this process. Single-molecule FISH data showed that the majority of these mutants accumulated mRNA within specific regions of the nucleus, which included 1) mRNAs within the nucleolus when nucleocytoplasmic transport, rRNA biogenesis, or RNA processing and surveillance was disrupted, 2) the buildup of mRNAs near transcription sites in 3′-end processing and chromosome segregation mutants, and 3) transcripts being enriched near nuclear pore complexes when components of the mRNA export machinery were mutated. These data show that alterations to various nuclear processes lead to the retention of mRNAs at discrete locations within the nucleus.
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Affiliation(s)
- Biplab Paul
- Department of Cell Biology, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Ben Montpetit
- Department of Cell Biology, University of Alberta, Edmonton, AB T6G 2H7, Canada
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16
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The exosome component Rrp6 is required for RNA polymerase II termination at specific targets of the Nrd1-Nab3 pathway. PLoS Genet 2015; 11:e1004999. [PMID: 25680078 PMCID: PMC4378619 DOI: 10.1371/journal.pgen.1004999] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Accepted: 01/13/2015] [Indexed: 12/11/2022] Open
Abstract
The exosome and its nuclear specific subunit Rrp6 form a 3’-5’ exonuclease complex that regulates diverse aspects of RNA biology including 3’ end processing and degradation of a variety of noncoding RNAs (ncRNAs) and unstable transcripts. Known targets of the nuclear exosome include short (<1000 bp) RNAPII transcripts such as small noncoding RNAs (snRNAs), cryptic unstable transcripts (CUTs), and some stable unannotated transcripts (SUTs) that are terminated by an Nrd1, Nab3, and Sen1 (NNS) dependent mechanism. NNS-dependent termination is coupled to RNA 3’ end processing and/or degradation by the Rrp6/exosome in yeast. Recent work suggests Nrd1 is necessary for transcriptome surveillance, regulating promoter directionality and suppressing antisense transcription independently of, or prior to, Rrp6 activity. It remains unclear whether Rrp6 is directly involved in termination; however, Rrp6 has been implicated in the 3’ end processing and degradation of ncRNA transcripts including CUTs. To determine the role of Rrp6 in NNS termination globally, we performed RNA sequencing (RNA-Seq) on total RNA and perform ChIP-exo analysis of RNA Polymerase II (RNAPII) localization. Deletion of RRP6 promotes hyper-elongation of multiple NNS-dependent transcripts resulting from both improperly processed 3’ RNA ends and faulty transcript termination at specific target genes. The defects in RNAPII termination cause transcriptome-wide changes in mRNA expression through transcription interference and/or antisense repression, similar to previously reported effects of depleting Nrd1 from the nucleus. Elongated transcripts were identified within all classes of known NNS targets with the largest changes in transcription termination occurring at CUTs. Interestingly, the extended transcripts that we have detected in our studies show remarkable similarity to Nrd1-unterminated transcripts at many locations, suggesting that Rrp6 acts with the NNS complex globally to promote transcription termination in addition to 3’ end RNA processing and/or degradation at specific targets. RNAPII is responsible for transcription of protein-coding genes and short, regulatory RNAs. In Saccharomyces cerevisiae, termination of RNAPII-transcribed RNAs ≤1000 bases requires the NNS complex (comprised of Nrd1, Nab3, and Sen1), processing by the exosome, and the nuclear specific catalytic subunit, Rrp6. It has been shown that Rrp6 interacts directly with Nrd1, but whether or not Rrp6 is required for NNS-dependent termination is unclear. Loss of Rrp6 function may result in extension (or inhibition of termination) of NNS-dependent transcripts, or Rrp6 may only function after the fact to carry out RNA 3’ end processing. Here, we performed in-depth differential expression analyses and compare RNA-sequencing data of transcript length and abundance in cells lacking RRP6 to ChIP-exo analysis of RNAPII localization. We find many transcripts that were defined as unterminated upon loss of Nrd1 activity are of similar length in rrp6Δ, and expression levels of downstream genes are significantly decreased. This suggests a similar transcription interference mechanism occurs in cells lacking either Nrd1 or Rrp6. Indeed we find increased RNAPII located downstream of its termination site at many know Nrd1-regulated transcripts. Overall, our findings clearly demonstrate that Rrp6 activity is required for efficient NNS termination in vivo.
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Efficient mRNA polyadenylation requires a ubiquitin-like domain, a zinc knuckle, and a RING finger domain, all contained in the Mpe1 protein. Mol Cell Biol 2014; 34:3955-67. [PMID: 25135474 DOI: 10.1128/mcb.00077-14] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Almost all eukaryotic mRNAs must be polyadenylated at their 3' ends to function in protein synthesis. This modification occurs via a large nuclear complex that recognizes signal sequences surrounding a poly(A) site on mRNA precursor, cleaves at that site, and adds a poly(A) tail. While the composition of this complex is known, the functions of some subunits remain unclear. One of these is a multidomain protein called Mpe1 in the yeast Saccharomyces cerevisiae and RBBP6 in metazoans. The three conserved domains of Mpe1 are a ubiquitin-like (UBL) domain, a zinc knuckle, and a RING finger domain characteristic of some ubiquitin ligases. We show that mRNA 3'-end processing requires all three domains of Mpe1 and that more than one region of Mpe1 is involved in contact with the cleavage/polyadenylation factor in which Mpe1 resides. Surprisingly, both the zinc knuckle and the RING finger are needed for RNA-binding activity. Consistent with a role for Mpe1 in ubiquitination, mutation of Mpe1 decreases the association of ubiquitin with Pap1, the poly(A) polymerase, and suppressors of mpe1 mutants are linked to ubiquitin ligases. Furthermore, an inhibitor of ubiquitin-mediated interactions blocks cleavage, demonstrating for the first time a direct role for ubiquitination in mRNA 3'-end processing.
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18
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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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19
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Largeot A, Paggetti J, Broséus J, Aucagne R, Lagrange B, Martin RZ, Berthelet J, Quéré R, Lucchi G, Ducoroy P, Bastie JN, Delva L. Symplekin, a polyadenylation factor, prevents MOZ and MLL activity on HOXA9 in hematopoietic cells. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1833:3054-3063. [DOI: 10.1016/j.bbamcr.2013.08.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 07/26/2013] [Accepted: 08/13/2013] [Indexed: 01/07/2023]
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20
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Abstract
Systemic response to DNA damage and other stresses is a complex process that includes changes in the regulation and activity of nearly all stages of gene expression. One gene regulatory mechanism used by eukaryotes is selection among alternative transcript isoforms that differ in polyadenylation [poly(A)] sites, resulting in changes either to the coding sequence or to portions of the 3' UTR that govern translation, stability, and localization. To determine the extent to which this means of regulation is used in response to DNA damage, we conducted a global analysis of poly(A) site usage in Saccharomyces cerevisiae after exposure to the UV mimetic, 4-nitroquinoline 1-oxide (4NQO). Two thousand thirty-one genes were found to have significant variation in poly(A) site distributions following 4NQO treatment, with a strong bias toward loss of short transcripts, including many with poly(A) sites located within the protein coding sequence (CDS). We further explored one possible mechanism that could contribute to the widespread differences in mRNA isoforms. The change in poly(A) site profile was associated with an inhibition of cleavage and polyadenylation in cell extract and a decrease in the levels of several key subunits in the mRNA 3'-end processing complex. Sequence analysis identified differences in the cis-acting elements that flank putatively suppressed and enhanced poly(A) sites, suggesting a mechanism that could discriminate between variable and constitutive poly(A) sites. Our analysis indicates that variation in mRNA length is an important part of the regulatory response to DNA damage.
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21
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Structural and biochemical analysis of the assembly and function of the yeast pre-mRNA 3' end processing complex CF I. Proc Natl Acad Sci U S A 2012; 109:21342-7. [PMID: 23236150 DOI: 10.1073/pnas.1214102110] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The accuracy of the 3'-end processing by cleavage and polyadenylation is essential for mRNA biogenesis and transcription termination. In yeast, two poorly conserved neighboring elements upstream of cleavage sites are important for accuracy and efficiency of this process. These two RNA sequences are recognized by the RNA binding proteins Hrp1 and Rna15, but efficient processing in vivo requires a bridging protein (Rna14), which forms a stable dimer of hetero-dimers with Rna15 to stabilize the RNA-protein complex. We earlier reported the structure of the ternary complex of Rna15 and Hrp1 bound to the RNA processing element. We now report the use of solution NMR to study the interaction of Hrp1 with the Rna14-Rna15 heterodimer in the presence and absence of 3'-end processing signals. By using methyl selective labeling on Hrp1, in vivo activity and pull-down assays, we were able to study this complex of several hundred kDa, identify the interface within Hrp1 responsible for recruitment of Rna14 and validate the functional significance of this interaction through structure-driven mutational analysis.
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22
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A complex containing the CPSF73 endonuclease and other polyadenylation factors associates with U7 snRNP and is recruited to histone pre-mRNA for 3'-end processing. Mol Cell Biol 2012; 33:28-37. [PMID: 23071092 DOI: 10.1128/mcb.00653-12] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Animal replication-dependent histone pre-mRNAs are processed at the 3' end by endonucleolytic cleavage that is not followed by polyadenylation. The cleavage reaction is catalyzed by CPSF73 and depends on the U7 snRNP and its integral component, Lsm11. A critical role is also played by the 220-kDa protein FLASH, which interacts with Lsm11. Here we demonstrate that the N-terminal regions of these two proteins form a platform that tightly interacts with a unique combination of polyadenylation factors: symplekin, CstF64, and all CPSF subunits, including the endonuclease CPSF73. The interaction is inhibited by alterations in each component of the FLASH/Lsm11 complex, including point mutations in FLASH that are detrimental for processing. The same polyadenylation factors are associated with the endogenous U7 snRNP and are recruited in a U7-dependent manner to histone pre-mRNA. Collectively, our studies identify the molecular mechanism that recruits the CPSF73 endonuclease to histone pre-mRNAs, reveal an unexpected complexity of the U7 snRNP, and suggest that in animal cells polyadenylation factors assemble into two alternative complexes-one specifically crafted to generate polyadenylated mRNAs and the other to generate nonpolyadenylated histone mRNAs that end with the stem-loop.
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23
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Ruepp MD, Schümperli D, Barabino SML. mRNA 3' end processing and more--multiple functions of mammalian cleavage factor I-68. WILEY INTERDISCIPLINARY REVIEWS-RNA 2012; 2:79-91. [PMID: 21956970 DOI: 10.1002/wrna.35] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The formation of defined 3(') ends is an important step in the biogenesis of mRNAs. In eukaryotic cells, all mRNA 3(') ends are generated by endonucleolytic cleavage of primary transcripts in reactions that are essentially posttranscriptional. Nevertheless, 3(') end formation is tightly connected to transcription in vivo, and a link with mRNA export to the cytoplasm has been postulated. Here, we briefly review the current knowledge about the two types of mRNA 3(') end processing reactions, cleavage/polyadenylation and histone RNA processing. We then focus on factors shared between these two reactions. In particular, we discuss evidence for new functions of the mammalian cleavage factor I subunit CF I(m) 68 in histone RNA 3(') processing and in the export of mature mRNAs from the nucleus to the cytoplasm.
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Affiliation(s)
- Marc-David Ruepp
- Institute of Cell Biology, University of Bern, Bern, Switzerland
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24
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Gordon JMB, Shikov S, Kuehner JN, Liriano M, Lee E, Stafford W, Poulsen MB, Harrison C, Moore C, Bohm A. Reconstitution of CF IA from overexpressed subunits reveals stoichiometry and provides insights into molecular topology. Biochemistry 2011; 50:10203-14. [PMID: 22026644 DOI: 10.1021/bi200964p] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Yeast cleavage factor I (CF I) is an essential complex of five proteins that binds signal sequences at the 3' end of yeast mRNA. CF I is required for correct positioning of a larger protein complex, CPF, which contains the catalytic subunits executing mRNA cleavage and polyadenylation. CF I is composed of two parts, CF IA and Hrp1. The CF IA has only four subunits, Rna14, Rna15, Pcf11, and Clp1, but the structural organization has not been fully established. Using biochemical and biophysical methods, we demonstrate that CF IA can be reconstituted from bacterially expressed proteins and that it has 2:2:1:1 stoichiometry of its four proteins, respectively. We also describe mutations that disrupt the dimer interface of Rna14 while preserving the other subunit interactions. On the basis of our results and existing interaction data, we present a topological model for heterohexameric CF IA and its association with RNA and Hrp1.
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Affiliation(s)
- James M B Gordon
- Department of Biochemistry, Tufts University School of Medicine, Boston, Massachusetts 02111, United States
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25
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Ghazy MA, Gordon JMB, Lee SD, Singh BN, Bohm A, Hampsey M, Moore C. The interaction of Pcf11 and Clp1 is needed for mRNA 3'-end formation and is modulated by amino acids in the ATP-binding site. Nucleic Acids Res 2011; 40:1214-25. [PMID: 21993299 PMCID: PMC3273803 DOI: 10.1093/nar/gkr801] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Polyadenylation of eukaryotic mRNAs contributes to stability, transport and translation, and is catalyzed by a large complex of conserved proteins. The Pcf11 subunit of the yeast CF IA factor functions as a scaffold for the processing machinery during the termination and polyadenylation of transcripts. Its partner, Clp1, is needed for mRNA processing, but its precise molecular role has remained enigmatic. We show that Clp1 interacts with the Cleavage–Polyadenylation Factor (CPF) through its N-terminal and central domains, and thus provides cross-factor connections within the processing complex. Clp1 is known to bind ATP, consistent with the reported RNA kinase activity of human Clp1. However, substitution of conserved amino acids in the ATP-binding site did not affect cell growth, suggesting that the essential function of yeast Clp1 does not involve ATP hydrolysis. Surprisingly, non-viable mutations predicted to displace ATP did not affect ATP binding but disturbed the Clp1–Pcf11 interaction. In support of the importance of this interaction, a mutation in Pcf11 that disrupts the Clp1 contact caused defects in growth, 3′-end processing and transcription termination. These results define Clp1 as a bridge between CF IA and CPF and indicate that the Clp1–Pcf11 interaction is modulated by amino acids in the conserved ATP-binding site of Clp1.
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Affiliation(s)
- Mohamed A Ghazy
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA 02111, USA
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26
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Haddad R, Maurice F, Viphakone N, Voisinet-Hakil F, Fribourg S, Minvielle-Sébastia L. An essential role for Clp1 in assembly of polyadenylation complex CF IA and Pol II transcription termination. Nucleic Acids Res 2011; 40:1226-39. [PMID: 21993300 PMCID: PMC3273802 DOI: 10.1093/nar/gkr800] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Polyadenylation is a co-transcriptional process that modifies mRNA 3′-ends in eukaryotes. In yeast, CF IA and CPF constitute the core 3′-end maturation complex. CF IA comprises Rna14p, Rna15p, Pcf11p and Clp1p. CF IA interacts with the C-terminal domain of RNA Pol II largest subunit via Pcf11p which links pre-mRNA 3′-end processing to transcription termination. Here, we analysed the role of Clp1p in 3′ processing. Clp1p binds ATP and interacts in CF IA with Pcf11p only. Depletion of Clp1p abolishes transcription termination. Moreover, we found that association of mutations in the ATP-binding domain and in the distant Pcf11p-binding region impair 3′-end processing. Strikingly, these mutations prevent not only Clp1p-Pcf11p interaction but also association of Pcf11p with Rna14p-Rna15p. ChIP experiments showed that Rna15p cross-linking to the 3′-end of a protein-coding gene is perturbed by these mutations whereas Pcf11p is only partially affected. Our study reveals an essential role of Clp1p in CF IA organization. We postulate that Clp1p transmits conformational changes to RNA Pol II through Pcf11p to couple transcription termination and 3′-end processing. These rearrangements likely rely on the correct orientation of ATP within Clp1p.
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27
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Johnson SA, Kim H, Erickson B, Bentley DL. The export factor Yra1 modulates mRNA 3' end processing. Nat Struct Mol Biol 2011; 18:1164-71. [PMID: 21947206 PMCID: PMC3307051 DOI: 10.1038/nsmb.2126] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2011] [Accepted: 07/20/2011] [Indexed: 11/09/2022]
Abstract
The Saccharomyces cerevisiae mRNA export adaptor Yra1 binds the Pcf11 subunit of cleavage-polyadenylation factor CF1A that links export to 3' end formation. We found that an unexpected consequence of this interaction is that Yra1 influences cleavage-polyadenylation. Yra1 competes with the CF1A subunit Clp1 for binding to Pcf11, and excess Yra1 inhibits 3' processing in vitro. Release of Yra1 at the 3' ends of genes coincides with recruitment of Clp1, and depletion of Yra1 enhances Clp1 recruitment within some genes. These results suggest that CF1A is not necessarily recruited as a complete unit; instead, Clp1 can be incorporated co-transcriptionally in a process regulated by Yra1. Yra1 depletion causes widespread changes in poly(A) site choice, particularly at sites where the efficiency element is divergently positioned. We propose that one way Yra1 modulates cleavage-polyadenylation is by influencing co-transcriptional assembly of the CF1A 3' processing factor.
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Affiliation(s)
- Sara A Johnson
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, Colorado, USA
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28
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Ezeokonkwo C, Zhelkovsky A, Lee R, Bohm A, Moore CL. A flexible linker region in Fip1 is needed for efficient mRNA polyadenylation. RNA (NEW YORK, N.Y.) 2011; 17:652-664. [PMID: 21282348 PMCID: PMC3062176 DOI: 10.1261/rna.2273111] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2010] [Accepted: 12/21/2010] [Indexed: 05/30/2023]
Abstract
Synthesis of the poly(A) tail of mRNA in Saccharomyces cerevisiae requires recruitment of the polymerase Pap1 to the 3' end of cleaved pre-mRNA. This is made possible by the tethering of Pap1 to the Cleavage/Polyadenylation Factor (CPF) by Fip1. We have recently reported that Fip1 is an unstructured protein in solution, and proposed that it might maintain this conformation as part of CPF, when bound to Pap1. However, the role that this feature of Fip1 plays in 3' end processing has not been investigated. We show here that Fip1 has a flexible linker in the middle of the protein, and that removal or replacement of the linker affects the efficiency of polyadenylation. However, the point of tethering is not crucial, as a fusion protein of Pap1 and Fip1 is fully functional in cells lacking genes encoding the essential individual proteins, and directly tethering Pap1 to RNA increases the rate of poly(A) addition. We also find that the linker region of Fip1 provides a platform for critical interactions with other parts of the processing machinery. Our results indicate that the Fip1 linker, through its flexibility and protein/protein interactions, allows Pap1 to reach the 3' end of the cleaved RNA and efficiently initiate poly(A) addition.
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Affiliation(s)
- Chukwudi Ezeokonkwo
- Department of Biochemistry, Tufts University School of Medicine and the Sackler Graduate School of Biomedical Sciences, Boston, Massachusetts 02111, USA
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29
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Sipling T, Zhai C, Panaretou B. Emw1p/YNL313cp is essential for maintenance of the cell wall in Saccharomyces cerevisiae. MICROBIOLOGY-SGM 2011; 157:1032-1041. [PMID: 21273246 DOI: 10.1099/mic.0.045971-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
There are six essential genes in the Saccharomyces cerevisiae genome which encode proteins bearing the tetratricopeptide repeat (TPR) domain that mediates protein-protein interaction. Thus far, the function of one of them, YNL313c, remains unknown. Our conditional mutants of YNL313c display osmoremedial temperature sensitivity, hypersensitivity to both Calcofluor White and low concentrations of SDS, and osmoremedial caffeine sensitivity. These are hallmarks of mutants that display cell wall defects. Accordingly we rename the gene as EMW1 (essential for maintenance of the cell wall). Loss of Emw1p function is not associated with abrogation of the cell wall integrity (CWI) MAP kinase cascade. Instead, emw1(ts) mutants activate this cascade even at permissive temperature, indicating that loss of Emw1p function does not cause a defect in sensors and effectors of cell wall signalling, but leads to a cell wall defect directly. Constitutive activation of the CWI cascade is reflected by the overproduction of chitin by emw1(ts) mutants, a compensatory response frequently displayed by cell wall mutants. Growth is restored to emw1(ts) mutants incubated at otherwise non-permissive temperature when GFA1 is overexpressed. GFA1 encodes the hexosephosphate aminotransferase that catalyses the rate-limiting step in the pathway that synthesizes the chitin precursor UDP-GlcNAc. The possibility that Emw1p is required for function of Gfa1p was ruled out, because the emw1(ts) phenotype persists when the requirement for Gfa1p is bypassed. Furthermore, if loss of Emw1p function leads to loss of function of Gfa1p, then chitin synthesis would be diminished. Instead, a stimulation of the synthesis of this polymer is detected. Consequently, the defect associated with emw1(ts) mutants may be associated with compromise in one of the remaining processes that depend on UDP-GlcNAc, namely N-glycosylation or glycosylphosphatidylinositol (GPI)-anchor synthesis.
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Affiliation(s)
- Tatjana Sipling
- Pharmaceutical Science Division, King's College London, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH, UK
| | - Chao Zhai
- Pharmaceutical Science Division, King's College London, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH, UK
| | - Barry Panaretou
- Pharmaceutical Science Division, King's College London, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH, UK
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30
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Xiang K, Nagaike T, Xiang S, Kilic T, Beh MM, Manley JL, Tong L. Crystal structure of the human symplekin-Ssu72-CTD phosphopeptide complex. Nature 2010; 467:729-33. [PMID: 20861839 PMCID: PMC3038789 DOI: 10.1038/nature09391] [Citation(s) in RCA: 131] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2010] [Accepted: 08/03/2010] [Indexed: 12/19/2022]
Abstract
Symplekin (Pta1 in yeast) is a scaffold in the large protein complex that is required for 3′-end cleavage and polyadenylation of eukaryotic messenger RNA precursors (pre-mRNAs) 1–4, and also participates in transcription initiation and termination by RNA polymerase II (Pol II) 5,6. Symplekin mediates interactions among many different proteins in this machinery 1,2,7–9, although the molecular basis for its function is not known. Here we report the crystal structure at 2.4 Å resolution of the N-terminal domain (residues 30–340) of human symplekin (Symp-N) in a ternary complex with the Pol II C-terminal domain (CTD) Ser5 phosphatase Ssu72 7,10–17 and a CTD Ser5 phosphopeptide. The N-terminal domain of symplekin has the ARM or HEAT fold, with seven pairs of anti-parallel α-helices arranged in the shape of an arc. The structure of Ssu72 has some similarity to that of low-molecular-weight phosphotyrosine protein phosphatase 18,19, although Ssu72 has a unique active site landscape as well as extra structural features at the C-terminus that is important for interaction with symplekin. Ssu72 is bound to the concave face of symplekin, and engineered mutations in this interface can abolish interactions between the two proteins. The CTD peptide is bound in the active site of Ssu72, unexpectedly with the pSer5-Pro6 peptide bond in the cis configuration, which contrasts with all other known CTD peptide conformations 20,21. While the active site of Ssu72 is about 25 Å away from the interface with symplekin, we found that the symplekin N-terminal domain stimulates Ssu72 CTD phosphatase activity in vitro. Furthermore, the N-terminal domain of symplekin inhibits polyadenylation in vitro, but importantly only when coupled to transcription. As catalytically active Ssu72 overcomes this inhibition, our results demonstrate a role for mammalian Ssu72 in transcription-coupled pre-mRNA 3′-end processing.
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Affiliation(s)
- Kehui Xiang
- Department of Biological Sciences, Columbia University, New York, New York 10027, USA
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31
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Leeper TC, Qu X, Lu C, Moore C, Varani G. Novel protein-protein contacts facilitate mRNA 3'-processing signal recognition by Rna15 and Hrp1. J Mol Biol 2010; 401:334-49. [PMID: 20600122 DOI: 10.1016/j.jmb.2010.06.032] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2009] [Revised: 06/10/2010] [Accepted: 06/10/2010] [Indexed: 12/22/2022]
Abstract
Precise 3'-end processing of mRNA is essential for correct gene expression, yet in yeast, 3'-processing signals consist of multiple ambiguous sequence elements. Two neighboring elements upstream of the cleavage site are particularly important for the accuracy (positioning element) and efficiency (efficiency element) of 3'-processing and are recognized by the RNA-binding proteins Rna15 and Hrp1, respectively. In vivo, these interactions are strengthened by the scaffolding protein Rna14 that stabilizes their association. The NMR structure of the 34 -kDa ternary complex of the RNA recognition motif (RRM) domains of Hrp1 and Rna15 bound to this pair of RNA elements was determined by residual dipolar coupling and paramagnetic relaxation experiments. It reveals how each of the proteins binds to RNA and introduces a novel class of protein-protein contact in regions of previously unknown function. These interdomain contacts had previously been overlooked in other multi-RRM structures, although a careful analysis suggests that they may be frequently present. Mutations in the regions of these contacts disrupt 3'-end processing, suggesting that they may structurally organize the ribonucleoprotein complexes responsible for RNA processing.
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Affiliation(s)
- Thomas C Leeper
- Department of Chemistry, University of Washington, Seattle, WA 98195-1700, USA.
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32
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The structure of the 5′-untranslated region of mammalian poly(A) polymerase-α mRNA suggests a mechanism of translational regulation. Mol Cell Biochem 2010; 340:91-6. [DOI: 10.1007/s11010-010-0405-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2009] [Accepted: 02/04/2010] [Indexed: 11/25/2022]
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33
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Millevoi S, Vagner S. Molecular mechanisms of eukaryotic pre-mRNA 3' end processing regulation. Nucleic Acids Res 2009; 38:2757-74. [PMID: 20044349 PMCID: PMC2874999 DOI: 10.1093/nar/gkp1176] [Citation(s) in RCA: 294] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Messenger RNA (mRNA) 3′ end formation is a nuclear process through which all eukaryotic primary transcripts are endonucleolytically cleaved and most of them acquire a poly(A) tail. This process, which consists in the recognition of defined poly(A) signals of the pre-mRNAs by a large cleavage/polyadenylation machinery, plays a critical role in gene expression. Indeed, the poly(A) tail of a mature mRNA is essential for its functions, including stability, translocation to the cytoplasm and translation. In addition, this process serves as a bridge in the network connecting the different transcription, capping, splicing and export machineries. It also participates in the quantitative and qualitative regulation of gene expression in a variety of biological processes through the selection of single or alternative poly(A) signals in transcription units. A large number of protein factors associates with this machinery to regulate the efficiency and specificity of this process and to mediate its interaction with other nuclear events. Here, we review the eukaryotic 3′ end processing machineries as well as the comprehensive set of regulatory factors and discuss the different molecular mechanisms of 3′ end processing regulation by proposing several overlapping models of regulation.
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Affiliation(s)
- Stefania Millevoi
- Institut National de la Santé et de la Recherche Médicale U563, Toulouse, F-31000, France.
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34
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Seoane S, Lamas-Maceiras M, Rodríguez-Torres AM, Freire-Picos MA. Involvement of Pta1, Pcf11 and a KlCYC1 AU-rich element in alternative RNA 3'-end processing selection in yeast. FEBS Lett 2009; 583:2843-8. [PMID: 19646984 DOI: 10.1016/j.febslet.2009.07.042] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2009] [Revised: 07/23/2009] [Accepted: 07/23/2009] [Indexed: 11/24/2022]
Abstract
This work reports the involvement of yeast RNA processing factors Pta1 and Pcf11 in alternative 3'-end RNA processing. The pta1-1 and pcf11-2 mutations changed the predominance of KlCYC1 1.14 and 1.5 kb transcript isoforms. Mutation of the KlCYC1 3'-UTR AU-rich sequence at positions 679-690 (mutant M1) altered transcript predominance. Moreover, expression of M1 in the yeast mutants partially suppressed their effects in the predominance pattern. The combination of the M1 and M2 (694-698 deletion) mutations abolished the alternative processing. Pta1 involvement in this selection was confirmed using the Pta1-td degron strain.
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Affiliation(s)
- Silvia Seoane
- Universidade da Coruña, Facultad de Ciencias, Campus da Zapateira S/N, 15071 A Coruña, Spain
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35
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Assembly of an export-competent mRNP is needed for efficient release of the 3'-end processing complex after polyadenylation. Mol Cell Biol 2009; 29:5327-38. [PMID: 19635808 DOI: 10.1128/mcb.00468-09] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Before polyadenylated mRNA is exported from the nucleus, the 3'-end processing complex is removed by a poorly described mechanism. In this study, we asked whether factors involved in mRNP maturation and export are also required for disassembly of the cleavage and polyadenylation complex. An RNA immunoprecipitation assay monitoring the amount of the cleavage factor (CF) IA component Rna15p associated with poly(A)(+) RNA reveals defective removal of Rna15p in mutants of the nuclear export receptor Mex67p as well as other factors important for assembly of an export-competent mRNP. In contrast, Rna15p is not retained in mutants of export factors that function primarily on the cytoplasmic side of the nuclear pore. Consistent with a functional interaction between Mex67p and the 3'-end processing complex, a mex67 mutant accumulates unprocessed SSA4 transcripts and exhibits a severe growth defect when this mutation is combined with mutation of Rna15p or another CF IA subunit, Rna14p. RNAs that become processed in a mex67 mutant have longer poly(A) tails both in vivo and in vitro. This influence of Mex67p on 3'-end processing is conserved, as depletion of its human homolog, TAP/NXF1, triggers mRNA hyperadenylation. Our results indicate a function for nuclear mRNP assembly factors in releasing the 3'-end processing complex once polyadenylation is complete.
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36
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A core complex of CPSF73, CPSF100, and Symplekin may form two different cleavage factors for processing of poly(A) and histone mRNAs. Mol Cell 2009; 34:322-32. [PMID: 19450530 DOI: 10.1016/j.molcel.2009.04.024] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2009] [Revised: 04/14/2009] [Accepted: 04/24/2009] [Indexed: 11/23/2022]
Abstract
Metazoan histone mRNAs are unique: their pre-mRNAs contain no introns, and the mRNAs are not polyadenylated, ending instead in a conserved stem-loop structure. In Drosophila, canonical poly(A) signals are located downstream of the normal cleavage site of each histone gene and are utilized when histone 3' end formation is inhibited. Here we define a subcomplex of poly(A) factors that are required for histone pre-mRNA processing. We demonstrate that Symplekin, CPSF73, and CPSF100 are present in a stable complex and interact with histone-specific processing factors. We use chromatin immunoprecipitation to show that Symplekin and CPSF73, but not CstF50, cotranscriptionally associate with histone genes. Depletion of SLBP recruits CstF50 to histone genes. Knockdown of CPSF160 or CstF64 downregulates Symplekin but does not affect histone pre-mRNA processing or association of Symplekin with the histone locus. These results suggest that a common core cleavage factor is required for processing of histone and polyadenylated pre-mRNAs.
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37
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Roth KM, Byam J, Fang F, Butler JS. Regulation of NAB2 mRNA 3'-end formation requires the core exosome and the Trf4p component of the TRAMP complex. RNA (NEW YORK, N.Y.) 2009; 15:1045-58. [PMID: 19369424 PMCID: PMC2685527 DOI: 10.1261/rna.709609] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The nuclear exosome functions in a variety of pathways catalyzing formation of mature RNA 3'-ends or the destruction of aberrant RNA transcripts. The RNA 3'-end formation activity of the exosome appeared restricted to small noncoding RNAs. However, the nuclear exosome controls the level of the mRNA encoding the poly(A)-binding protein Nab2p in a manner requiring an A(26) sequence in the mRNA 3' untranslated regions (UTR), and the activities of Nab2p and the exosome-associated exoribonuclease Rrp6p. Here we show that the A(26) sequence inhibits normal 3'-end processing of NAB2 mRNA in vivo and in vitro, and makes formation of the mature 3'-end dependent on trimming of the transcript by the core exosome and the Trf4p component of the TRAMP complex from a downstream site. The detection of mature, polyadenylated transcripts ending at, or within, the A(26) sequence indicates that exosome trimming sometimes gives way to polyadenylation of the mRNA. Alternatively, Rrp6p and the TRAMP-associated Mtr4p degrade these transcripts thereby limiting the amount of Nab2p in the cell. These findings suggest that NAB2 mRNA 3'-end formation requires the exosome and TRAMP complex, and that competition between polyadenylation and Rrp6p-dependent degradation controls the level of this mRNA.
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Affiliation(s)
- Kelly M Roth
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, New York 14642, USA
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38
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Functional interaction of the Ess1 prolyl isomerase with components of the RNA polymerase II initiation and termination machineries. Mol Cell Biol 2009; 29:2925-34. [PMID: 19332564 DOI: 10.1128/mcb.01655-08] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The C-terminal domain (CTD) of the largest subunit of RNA polymerase II (Pol II) is a reiterated heptad sequence (Tyr1-Ser2-Pro3-Thr4-Ser5-Pro6-Ser7) that plays a key role in the transcription cycle, coordinating the exchange of transcription and RNA processing factors. The structure of the CTD is flexible and undergoes conformational changes in response to serine phosphorylation and proline isomerization. Here we report that the Ess1 peptidyl prolyl isomerase functionally interacts with the transcription initiation factor TFIIB and with the Ssu72 CTD phosphatase and Pta1 components of the CPF 3'-end processing complex. The ess1(A144T) and ess1(H164R) mutants, initially described by Hanes and coworkers (Yeast 5:55-72, 1989), accumulate the pSer5 phosphorylated form of Pol II; confer phosphate, galactose, and inositol auxotrophies; and fail to activate PHO5, GAL10, and INO1 reporter genes. These mutants are also defective for transcription termination, but in vitro experiments indicate that this defect is not caused by altering the processing efficiency of the cleavage/polyadenylation machinery. Consistent with a role in initiation and termination, Ess1 associates with the promoter and terminator regions of the PMA1 and PHO5 genes. We propose that Ess1 facilitates pSer5-Pro6 dephosphorylation by generating the CTD structural conformation recognized by the Ssu72 phosphatase and that pSer5 dephosphorylation affects both early and late stages of the transcription cycle.
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39
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The essential N terminus of the Pta1 scaffold protein is required for snoRNA transcription termination and Ssu72 function but is dispensable for pre-mRNA 3'-end processing. Mol Cell Biol 2009; 29:2296-307. [PMID: 19188448 DOI: 10.1128/mcb.01514-08] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Saccharomyces cerevisiae Pta1 is a component of the cleavage/polyadenylation factor (CPF) 3'-end processing complex and functions in pre-mRNA cleavage, poly(A) addition, and transcription termination. In this study, we investigated the role of the N-terminal region of Pta1 in transcription and processing. We report that a deletion of the first 75 amino acids (pta1-Delta75) causes thermosensitive growth, while the deletion of an additional 25 amino acids is lethal. The pta1-Delta75 mutant is defective for snoRNA termination, RNA polymerase II C-terminal domain Ser5-P dephosphorylation, and gene looping but is fully functional for mRNA 3'-end processing. Furthermore, different regions of Pta1 interact with the CPF subunits Ssu72, Pti1, and Ysh1, supporting the idea that Pta1 acts as a scaffold to organize CPF. The first 300 amino acids of Pta1 are sufficient for interactions with Ssu72, which is needed for pre-mRNA cleavage. By the degron-mediated depletion of Pta1, we show that the removal of this essential region leads to a loss of Ssu72, yet surprisingly, in vitro cleavage and polyadenylation remain efficient. In addition, a fragment containing amino acids 1 to 300 suppresses 3'-end processing in wild-type extracts. These findings suggest that the amino terminus of Pta1 has an inhibitory effect and that this effect can be neutralized through the interaction with Ssu72.
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40
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Dermody JL, Dreyfuss JM, Villén J, Ogundipe B, Gygi SP, Park PJ, Ponticelli AS, Moore CL, Buratowski S, Bucheli ME. Unphosphorylated SR-like protein Npl3 stimulates RNA polymerase II elongation. PLoS One 2008; 3:e3273. [PMID: 18818768 PMCID: PMC2538588 DOI: 10.1371/journal.pone.0003273] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2008] [Accepted: 09/01/2008] [Indexed: 01/04/2023] Open
Abstract
The production of a functional mRNA is regulated at every step of transcription. An area not well-understood is the transition of RNA polymerase II from elongation to termination. The S. cerevisiae SR-like protein Npl3 functions to negatively regulate transcription termination by antagonizing the binding of polyA/termination proteins to the mRNA. In this study, Npl3 is shown to interact with the CTD and have a direct stimulatory effect on the elongation activity of the polymerase. The interaction is inhibited by phosphorylation of Npl3. In addition, Casein Kinase 2 was found to be required for the phosphorylation of Npl3 and affect its ability to compete against Rna15 (Cleavage Factor I) for binding to polyA signals. Our results suggest that phosphorylation of Npl3 promotes its dissociation from the mRNA/RNAP II, and contributes to the association of the polyA/termination factor Rna15. This work defines a novel role for Npl3 in elongation and its regulation by phosphorylation.
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Affiliation(s)
- Jessica L. Dermody
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Jonathan M. Dreyfuss
- Harvard-Partners Center for Genetics and Genomics, Boston, Massachusetts, United States of America
| | - Judit Villén
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Babatunde Ogundipe
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Steven P. Gygi
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Peter J. Park
- Harvard-Partners Center for Genetics and Genomics, Boston, Massachusetts, United States of America
| | - Alfred S. Ponticelli
- Department of Biochemistry, School of Medicine and Biomedical Sciences, State University of New York, Buffalo, New York, United States of America
| | - Claire L. Moore
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Stephen Buratowski
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Miriam E. Bucheli
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
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41
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Nuclear mRNA surveillance in THO/sub2 mutants is triggered by inefficient polyadenylation. Mol Cell 2008; 31:91-103. [PMID: 18614048 DOI: 10.1016/j.molcel.2008.04.030] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2007] [Revised: 12/23/2007] [Accepted: 04/29/2008] [Indexed: 11/23/2022]
Abstract
The yeast THO complex and the associated RNA helicase Sub2p are important mRNP maturation factors. Transcripts produced in THO/sub2 mutants are subject to degradation by a surveillance mechanism that involves the nuclear RNA exosome. Here we show that inefficient polyadenylation forms the basis of this accelerated mRNA decay. A genetic screen reveals extensive interactions between deletions of THO subunits and mRNA 3' end processing mutants. Nuclear run-ons strengthen this link by showing premature transcription termination close to polyadenylation sites in THO/sub2 mutants in vivo. Moreover, in vitro, pre-mRNA substrates are poorly polyadenylated and consequently unstable in extracts from THO/sub2 mutant strains. Decreased polyadenylation correlates with a specific downregulation of the poly(A)-polymerase cofactor Fip1p by the ubiquitin/proteasome pathway. Both polyadenylation defects and Fip1p instability depend on the nuclear exosome component Rrp6p and its activator Trf4p. We suggest that removal of aberrant mRNA is facilitated by direct regulation of polyadenylation activity.
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Ben-Aroya S, Coombes C, Kwok T, O'Donnell KA, Boeke JD, Hieter P. Toward a comprehensive temperature-sensitive mutant repository of the essential genes of Saccharomyces cerevisiae. Mol Cell 2008; 30:248-58. [PMID: 18439903 DOI: 10.1016/j.molcel.2008.02.021] [Citation(s) in RCA: 172] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2007] [Revised: 01/18/2008] [Accepted: 02/07/2008] [Indexed: 11/16/2022]
Abstract
The Saccharomyces cerevisiae gene deletion project revealed that approximately 20% of yeast genes are required for viability. The analysis of essential genes traditionally relies on conditional mutants, typically temperature-sensitive (ts) alleles. We developed a systematic approach (termed "diploid shuffle") useful for generating a ts allele for each essential gene in S. cerevisiae and for improved genetic manipulation of mutant alleles and gene constructs in general. Importantly, each ts allele resides at its normal genomic locus, flanked by specific cognate UPTAG and DNTAG bar codes. A subset of 250 ts mutants, including ts alleles for all uncharacterized essential genes and prioritized for genes with human counterparts, is now ready for distribution. The importance of this collection is demonstrated by biochemical and genetic screens that reveal essential genes involved in RNA processing and maintenance of chromosomal stability.
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Affiliation(s)
- Shay Ben-Aroya
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
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43
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Abstract
Most eukaryotic mRNA precursors (premRNAs) must undergo extensive processing, including cleavage and polyadenylation at the 3'-end. Processing at the 3'-end is controlled by sequence elements in the pre-mRNA (cis elements) as well as protein factors. Despite the seeming biochemical simplicity of the processing reactions, more than 14 proteins have been identified for the mammalian complex, and more than 20 proteins have been identified for the yeast complex. The 3'-end processing machinery also has important roles in transcription and splicing. The mammalian machinery contains several sub-complexes, including cleavage and polyadenylation specificity factor, cleavage stimulation factor, cleavage factor I, and cleavage factor II. Additional protein factors include poly(A) polymerase, poly(A)-binding protein, symplekin, and the C-terminal domain of RNA polymerase II largest subunit. The yeast machinery includes cleavage factor IA, cleavage factor IB, and cleavage and polyadenylation factor.
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Affiliation(s)
- C. R. Mandel
- Department of Biological Sciences, Columbia University, New York, NY 10027 USA
| | - Y. Bai
- Department of Biological Sciences, Columbia University, New York, NY 10027 USA
| | - L. Tong
- Department of Biological Sciences, Columbia University, New York, NY 10027 USA
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44
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Translational control by cytoplasmic polyadenylation in Xenopus oocytes. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2008; 1779:217-29. [PMID: 18316045 PMCID: PMC2323027 DOI: 10.1016/j.bbagrm.2008.02.002] [Citation(s) in RCA: 155] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/21/2007] [Revised: 01/30/2008] [Accepted: 02/04/2008] [Indexed: 12/21/2022]
Abstract
Elongation of the poly(A) tails of specific mRNAs in the cytoplasm is a crucial regulatory step in oogenesis and early development of many animal species. The best studied example is the regulation of translation by cytoplasmic polyadenylation elements (CPEs) in the 3′ untranslated region of mRNAs involved in Xenopus oocyte maturation. In this review we discuss the mechanism of translational control by the CPE binding protein (CPEB) in Xenopus oocytes as follows:The cytoplasmic polyadenylation machinery such as CPEB, the subunits of cleavage and polyadenylation specificity factor (CPSF), symplekin, Gld-2 and poly(A) polymerase (PAP). The signal transduction that leads to the activation of CPE-mediated polyadenylation during oocyte maturation, including the potential roles of kinases such as MAPK, Aurora A, CamKII, cdk1/Ringo and cdk1/cyclin B. The role of deadenylation and translational repression, including the potential involvement of PARN, CCR4/NOT, maskin, pumilio, Xp54 (Ddx6, Rck), other P-body components and isoforms of the cap binding initiation factor eIF4E.
Finally we discuss some of the remaining questions regarding the mechanisms of translational regulation by cytoplasmic polyadenylation and give our view on where our knowledge is likely to be expanded in the near future.
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45
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Bucheli ME, He X, Kaplan CD, Moore CL, Buratowski S. Polyadenylation site choice in yeast is affected by competition between Npl3 and polyadenylation factor CFI. RNA (NEW YORK, N.Y.) 2007; 13:1756-64. [PMID: 17684230 PMCID: PMC1986811 DOI: 10.1261/rna.607207] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Multiple steps in mRNA processing and transcription are coupled. Notably, the processing of mRNA 3' ends is linked to transcription termination by RNA polymerase II. Previously, we found that the yeast hnRNP protein Npl3 can negatively regulate 3' end mRNA formation and termination at the GAL1 gene. Here we show that overexpression of the Hrp1 or Rna14 subunits of the CF IA polyadenylation factor increases recognition of a weakened polyadenylation site. Genetic interactions of mutant alleles of NPL3 or HRP1 with RNA15 also indicate antagonism between these factors. Npl3 competes with Rna15 for binding to a polyadenylation precursor and inhibits cleavage and polyadenylation in vitro. These results suggest that an important function of hnRNP proteins is to ensure the fidelity of mRNA processing. Our results support a model in which balanced competition of Npl3 with mRNA processing factors may promote recognition of proper polyadenylation sites while suppressing cryptic sites.
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Affiliation(s)
- Miriam E Bucheli
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA
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46
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Atanasiu D, Fraser NW. The stable 2-kilobase latency-associated transcript of herpes simplex virus type 1 can alter the assembly of the 60S ribosomal subunit and is exported from nucleus to cytoplasm by a CRM1-dependent pathway. J Virol 2007; 81:7695-701. [PMID: 17494083 PMCID: PMC1933333 DOI: 10.1128/jvi.00282-07] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2007] [Accepted: 04/30/2007] [Indexed: 11/20/2022] Open
Abstract
During latency of herpes simplex virus type 1 in the neurons of the peripheral nervous system, the major transcript detected is the 2-kb latency-associated transcript (LAT) intron. During lytic infection, this intron has been shown to associate with ribosomes, suggesting a role in modifying the translational machinery of infected cells. In this study we show, using LAT-transfected cells, that the interaction of the intron with the 60S ribosomal subunit leads to irreversible changes in the sedimentation profile of this subunit in the nucleus. Furthermore, the 2-kb LAT intron is transported to the cytoplasm as part of the 60S ribosomal subunit, using a CRM1-dependent pathway.
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Affiliation(s)
- Doina Atanasiu
- Department of Microbiology, University of Pennsylvania School of Medicine, 3610 Hamilton Walk, Philadelphia, PA 19104, USA
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47
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Dominski Z. Nucleases of the metallo-beta-lactamase family and their role in DNA and RNA metabolism. Crit Rev Biochem Mol Biol 2007; 42:67-93. [PMID: 17453916 DOI: 10.1080/10409230701279118] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Proteins of the metallo-beta-lactamase family with either demonstrated or predicted nuclease activity have been identified in a number of organisms ranging from bacteria to humans and has been shown to be important constituents of cellular metabolism. Nucleases of this family are believed to utilize a zinc-dependent mechanism in catalysis and function as 5' to 3' exonucleases and or endonucleases in such processes as 3' end processing of RNA precursors, DNA repair, V(D)J recombination, and telomere maintenance. Examples of metallo-beta-lactamase nucleases include CPSF-73, a known component of the cleavage/polyadenylation machinery, which functions as the endonuclease in 3' end formation of both polyadenylated and histone mRNAs, and Artemis that opens DNA hairpins during V(D)J recombination. Mutations in two metallo-beta-lactamase nucleases have been implicated in human diseases: tRNase Z required for 3' processing of tRNA precursors has been linked to the familial form of prostate cancer, whereas inactivation of Artemis causes severe combined immunodeficiency (SCID). There is also a group of as yet uncharacterized proteins of this family in bacteria and archaea that based on sequence similarity to CPSF-73 are predicted to function as nucleases in RNA metabolism. This article reviews the cellular roles of nucleases of the metallo-beta-lactamase family and the recent advances in studying these proteins.
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Affiliation(s)
- Zbigniew Dominski
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA.
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48
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Dominski Z, Marzluff WF. Formation of the 3' end of histone mRNA: getting closer to the end. Gene 2007; 396:373-90. [PMID: 17531405 PMCID: PMC2888136 DOI: 10.1016/j.gene.2007.04.021] [Citation(s) in RCA: 136] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2007] [Accepted: 04/09/2007] [Indexed: 11/17/2022]
Abstract
Nearly all eukaryotic mRNAs end with a poly(A) tail that is added to their 3' end by the ubiquitous cleavage/polyadenylation machinery. The only known exceptions to this rule are metazoan replication-dependent histone mRNAs, which end with a highly conserved stem-loop structure. This distinct 3' end is generated by specialized 3' end processing machinery that cleaves histone pre-mRNAs 4-5 nucleotides downstream of the stem-loop and consists of the U7 small nuclear RNP (snRNP) and number of protein factors. Recently, the U7 snRNP has been shown to contain a unique Sm core that differs from that of the spliceosomal snRNPs, and an essential heat labile processing factor has been identified as symplekin. In addition, cross-linking studies have pinpointed CPSF-73 as the endonuclease, which catalyzes the cleavage reaction. Thus, many of the critical components of the 3' end processing machinery are now identified. Strikingly, this machinery is not as unique as initially thought but contains at least two factors involved in cleavage/polyadenylation, suggesting that the two mechanisms have a common evolutionary origin. The greatest challenge that lies ahead is to determine how all these factors interact with each other to form a catalytically competent processing complex capable of cleaving histone pre-mRNAs.
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Affiliation(s)
- Zbigniew Dominski
- Program in Molecular Biology and Biotechnology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
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49
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Kim JH, Richter JD. Opposing polymerase-deadenylase activities regulate cytoplasmic polyadenylation. Mol Cell 2006; 24:173-83. [PMID: 17052452 DOI: 10.1016/j.molcel.2006.08.016] [Citation(s) in RCA: 189] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2006] [Revised: 07/11/2006] [Accepted: 08/10/2006] [Indexed: 10/24/2022]
Abstract
Cytoplasmic polyadenylation is one mechanism that regulates translation in early animal development. In Xenopus oocytes, polyadenylation of dormant mRNAs, including cyclin B1, is controlled by the cis-acting cytoplasmic polyadenylation element (CPE) and hexanucleotide AAUAAA through associations with CPEB and CPSF, respectively. Previously, we demonstrated that the scaffold protein symplekin contacts CPEB and CPSF and helps them interact with Gld2, a poly(A) polymerase. Here, we report the mechanism by which poly(A) tail length is regulated. Cyclin B1 pre-mRNA acquires a long poly(A) tail in the nucleus that is subsequently shortened in the cytoplasm. The shortening is controlled by CPEB and PARN, a poly(A)-specific ribonuclease. Gld2 and PARN both reside in the CPEB-containing complex. However, because PARN is more active than Gld2, the poly(A) tail is short. When oocytes mature, CPEB phosphorylation causes PARN to be expelled from the ribonucleoprotein complex, which allows Gld2 to elongate poly(A) by default.
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Affiliation(s)
- Jong Heon Kim
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
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50
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Zhelkovsky A, Tacahashi Y, Nasser T, He X, Sterzer U, Jensen TH, Domdey H, Moore C. The role of the Brr5/Ysh1 C-terminal domain and its homolog Syc1 in mRNA 3'-end processing in Saccharomyces cerevisiae. RNA (NEW YORK, N.Y.) 2006; 12:435-45. [PMID: 16431986 PMCID: PMC1383582 DOI: 10.1261/rna.2267606] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The cleavage/polyadenylation factor (CPF) of Saccharomyces cerevisiae is thought to provide the catalytic activities of the mRNA 3'-end processing machinery, which include endonucleolytic cleavage at the poly(A) site, followed by synthesis of an adenosine polymer onto the new 3'-end by the CPF subunit Pap1. Because of similarity to other nucleases in the metallo-beta-lactamase family, the Brr5/Ysh1 subunit has been proposed to be the endonuclease. The C-terminal domain of Brr5 lies outside of beta-lactamase homology, and its function has not been elucidated. We show here that this region of Brr5 is necessary for cell viability and mRNA 3'-end processing. It is highly homologous to another CPF subunit, Syc1. Syc1 is not essential, but its removal improves the growth of other processing mutants at restrictive temperatures and restores in vitro processing activity to cleavage/ polyadenylation-defective brr5-1 extract. Our findings suggest that Syc1, by mimicking the essential Brr5 C-terminus, serves as a negative regulator of mRNA 3'-end formation.
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Affiliation(s)
- Alexander Zhelkovsky
- Department of Molecular Microbiology, Tufts University School of Medicine, Boston, MA 02111, USA
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