1
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Vdovina YA, Kurshakova MM, Georgieva SG, Kopytova DV. PCID2 Subunit of the Drosophila TREX-2 Complex Has Two RNA-Binding Regions. Curr Issues Mol Biol 2023; 45:5662-5676. [PMID: 37504273 PMCID: PMC10378293 DOI: 10.3390/cimb45070357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 06/29/2023] [Accepted: 06/29/2023] [Indexed: 07/29/2023] Open
Abstract
Drosophila PCID2 is a subunit of the TREX-2 mRNA nuclear export complex. Although the complex has long been studied in eukaryotes, it is still unclear how TREX-2 interacts with mRNA in multicellular organisms. Here, the interaction between Drosophila PCID2 and the ras2 RNA was studied by EMSA. We show that the C-terminal region of the WH domain of PCID2 specifically binds the 3'-noncoding region of the ras2 RNA. While the same region of PCID2 interacts with the Xmas-2 subunit of the TREX-2 complex, PCID2 interacts with RNA independently of Xmas-2. An additional RNA-binding region (M region) was identified in the N-terminal part of the PCI domain and found to bind RNA nonspecifically. Point mutations of evolutionarily conserved amino acid residues in this region completely abolish the PCID2-RNA interaction, while a deletion of the C-terminal domain only partly decreases it. Thus, the specific interaction of PCID2 with RNA requires nonspecific PCID2-RNA binding.
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Affiliation(s)
- Yulia A Vdovina
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Maria M Kurshakova
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Sofia G Georgieva
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Daria V Kopytova
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia
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2
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The proximal proteome of 17 SARS-CoV-2 proteins links to disrupted antiviral signaling and host translation. PLoS Pathog 2021; 17:e1009412. [PMID: 34597346 PMCID: PMC8513853 DOI: 10.1371/journal.ppat.1009412] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 10/13/2021] [Accepted: 08/27/2021] [Indexed: 12/23/2022] Open
Abstract
Viral proteins localize within subcellular compartments to subvert host machinery and promote pathogenesis. To study SARS-CoV-2 biology, we generated an atlas of 2422 human proteins vicinal to 17 SARS-CoV-2 viral proteins using proximity proteomics. This identified viral proteins at specific intracellular locations, such as association of accessary proteins with intracellular membranes, and projected SARS-CoV-2 impacts on innate immune signaling, ER-Golgi transport, and protein translation. It identified viral protein adjacency to specific host proteins whose regulatory variants are linked to COVID-19 severity, including the TRIM4 interferon signaling regulator which was found proximal to the SARS-CoV-2 M protein. Viral NSP1 protein adjacency to the EIF3 complex was associated with inhibited host protein translation whereas ORF6 localization with MAVS was associated with inhibited RIG-I 2CARD-mediated IFNB1 promoter activation. Quantitative proteomics identified candidate host targets for the NSP5 protease, with specific functional cleavage sequences in host proteins CWC22 and FANCD2. This data resource identifies host factors proximal to viral proteins in living human cells and nominates pathogenic mechanisms employed by SARS-CoV-2. SARS-CoV-2 is the latest pathogenic coronavirus to emerge as a public health threat. We create a database of proximal host proteins to 17 SARS-CoV-2 viral proteins. We validate that NSP1 is proximal to the EIF3 translation initiation complex and is a potent inhibitor of translation. We also identify ORF6 antagonism of RNA-mediate innate immune signaling. We produce a database of potential host targets of the viral protease NSP5, and create a fluorescence-based assay to screen cleavage of peptide sequences. We believe that this data will be useful for identifying roles for many of the uncharacterized SARS-CoV-2 proteins and provide insights into the pathogenicity of new or emerging coronaviruses.
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3
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The Mammalian Ecdysoneless Protein Interacts with RNA Helicase DDX39A To Regulate Nuclear mRNA Export. Mol Cell Biol 2021; 41:e0010321. [PMID: 33941617 PMCID: PMC8224239 DOI: 10.1128/mcb.00103-21] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The mammalian orthologue of ecdysoneless (ECD) protein is required for embryogenesis, cell cycle progression, and mitigation of endoplasmic reticulum stress. Here, we identified key components of the mRNA export complexes as binding partners of ECD and characterized the functional interaction of ECD with key mRNA export-related DEAD BOX protein helicase DDX39A. We find that ECD is involved in RNA export through its interaction with DDX39A. ECD knockdown (KD) blocks mRNA export from the nucleus to the cytoplasm, which is rescued by expression of full-length ECD but not an ECD mutant that is defective in interaction with DDX39A. We have previously shown that ECD protein is overexpressed in ErbB2+ breast cancers (BC). In this study, we extended the analyses to two publicly available BC mRNA The Cancer Genome Atlas (TCGA) and Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) data sets. In both data sets, ECD mRNA overexpression correlated with short patient survival, specifically ErbB2+ BC. In the METABRIC data set, ECD overexpression also correlated with poor patient survival in triple-negative breast cancer (TNBC). Furthermore, ECD KD in ErbB2+ BC cells led to a decrease in ErbB2 mRNA level due to a block in its nuclear export and was associated with impairment of oncogenic traits. These findings provide novel mechanistic insight into the physiological and pathological functions of ECD.
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4
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Glukhova AA, Kurshakova MM, Nabirochkina EN, Georgieva SG, Kopytova DV. PCID2, a subunit of the Drosophila TREX-2 nuclear export complex, is essential for both mRNA nuclear export and its subsequent cytoplasmic trafficking. RNA Biol 2021; 18:1969-1980. [PMID: 33602059 DOI: 10.1080/15476286.2021.1885198] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
The TREX-2 complex is essential for the general nuclear mRNA export in eukaryotes. TREX-2 interacts with the nuclear pore and transcriptional apparatus and links transcription to the mRNA export. However, it remains poorly understood how the TREX-2-dependent nuclear export is connected to the subsequent stages of mRNA trafficking. Here, we show that the PCID2 subunit of Drosophila TREX-2 is present in the cytoplasm of the cell. The cytoplasmic PCID2 directly interacts with the NudC protein and this interaction maintains its stability in the cytoplasm. Moreover, PCID2 is associated with the cytoplasmic mRNA and microtubules. The PCID2 knockdown blocks nuclear export of mRNA and also affects the general mRNA transport into the cytoplasm. These data suggest that PCID2 could be the link between the nuclear TREX-2-dependent export and the subsequent cytoplasmic trafficking of mRNA.
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Affiliation(s)
- A A Glukhova
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - M M Kurshakova
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - E N Nabirochkina
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - S G Georgieva
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia.,Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - D V Kopytova
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
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5
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Nie M, Oravcová M, Jami‐Alahmadi Y, Wohlschlegel JA, Lazzerini‐Denchi E, Boddy MN. FAM111A induces nuclear dysfunction in disease and viral restriction. EMBO Rep 2021; 22:e50803. [PMID: 33369867 PMCID: PMC7857424 DOI: 10.15252/embr.202050803] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 11/17/2020] [Accepted: 11/20/2020] [Indexed: 12/13/2022] Open
Abstract
Mutations in the nuclear trypsin-like serine protease FAM111A cause Kenny-Caffey syndrome (KCS2) with hypoparathyroidism and skeletal dysplasia or perinatally lethal osteocraniostenosis (OCS). In addition, FAM111A was identified as a restriction factor for certain host range mutants of the SV40 polyomavirus and VACV orthopoxvirus. However, because FAM111A function is poorly characterized, its roles in restricting viral replication and the etiology of KCS2 and OCS remain undefined. We find that FAM111A KCS2 and OCS patient mutants are hyperactive and cytotoxic, inducing apoptosis-like phenotypes such as disruption of nuclear structure and pore distribution, in a protease-dependent manner. Moreover, wild-type FAM111A activity causes similar nuclear phenotypes, including the loss of nuclear barrier function, when SV40 host range mutants attempt to replicate in restrictive cells. Interestingly, pan-caspase inhibitors do not block these FAM111A-induced phenotypes, implying it acts independently or upstream of caspases. In this regard, we identify nucleoporins and the associated GANP transcription/replication factor as FAM111A interactors and candidate targets. Overall, we reveal a potentially unifying mechanism through which deregulated FAM111A activity restricts viral replication and causes KCS2 and OCS.
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Affiliation(s)
- Minghua Nie
- Department of Molecular MedicineThe Scripps Research InstituteLa JollaCAUSA
| | - Martina Oravcová
- Department of Molecular MedicineThe Scripps Research InstituteLa JollaCAUSA
| | - Yasaman Jami‐Alahmadi
- Department of Biological ChemistryDavid Geffen School of MedicineUniversity of CaliforniaLos AngelesCAUSA
| | - James A Wohlschlegel
- Department of Biological ChemistryDavid Geffen School of MedicineUniversity of CaliforniaLos AngelesCAUSA
| | | | - Michael N Boddy
- Department of Molecular MedicineThe Scripps Research InstituteLa JollaCAUSA
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6
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The Nuclear Pore Complex and mRNA Export in Cancer. Cancers (Basel) 2020; 13:cancers13010042. [PMID: 33375634 PMCID: PMC7796397 DOI: 10.3390/cancers13010042] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 12/11/2020] [Accepted: 12/22/2020] [Indexed: 02/07/2023] Open
Abstract
Export of mRNAs from the nucleus to the cytoplasm is a key regulatory step in the expression of proteins. mRNAs are transported through the nuclear pore complex (NPC). Export of mRNAs responds to a variety of cellular stimuli and stresses. Revelations of the specific effects elicited by NPC components and associated co-factors provides a molecular basis for the export of selected RNAs, independent of bulk mRNA export. Aberrant RNA export has been observed in primary human cancer specimens. These cargo RNAs encode factors involved in nearly all facets of malignancy. Indeed, the NPC components involved in RNA export as well as the RNA export machinery can be found to be dysregulated, mutated, or impacted by chromosomal translocations in cancer. The basic mechanisms associated with RNA export with relation to export machinery and relevant NPC components are described. Therapeutic strategies targeting this machinery in clinical trials is also discussed. These findings firmly position RNA export as a targetable feature of cancer along with transcription and translation.
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7
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Moore S, Rabichow BE, Sattler R. The Hitchhiker's Guide to Nucleocytoplasmic Trafficking in Neurodegeneration. Neurochem Res 2020; 45:1306-1327. [PMID: 32086712 DOI: 10.1007/s11064-020-02989-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 02/12/2020] [Accepted: 02/14/2020] [Indexed: 12/12/2022]
Abstract
The widespread nature of nucleocytoplasmic trafficking defects and protein accumulation suggests distinct yet overlapping mechanisms in a variety of neurodegenerative diseases. Detailed understanding of the cellular pathways involved in nucleocytoplasmic transport and its dysregulation are essential for elucidating neurodegenerative pathogenesis and pinpointing potential areas for therapeutic intervention. The transport of cargos from the nucleus to the cytoplasm is generally regulated by the structure and function of the nuclear pore as well as the karyopherin α/β, importin, exportin, and mRNA export mechanisms. The disruption of these crucial transport mechanisms has been extensively described in the context of neurodegenerative diseases. One common theme in neurodegeneration is the cytoplasmic aggregation of proteins, including nuclear RNA binding proteins, repeat expansion associated gene products, and tau. These cytoplasmic aggregations are partly a consequence of failed nucleocytoplasmic transport machinery, but can also further disrupt transport, creating cyclical feed-forward mechanisms that exacerbate neurodegeneration. Here we describe the canonical mechanisms that regulate nucleocytoplasmic trafficking as well as how these mechanisms falter in neurodegenerative diseases.
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Affiliation(s)
- Stephen Moore
- Department of Neurobiology, Barrow Neurological Institute, 350 W Thomas Road, Phoenix, AZ, 85013, USA.,School of Life Sciences, Arizona State University, Tempe, AZ, USA
| | - Benjamin E Rabichow
- Department of Neurobiology, Barrow Neurological Institute, 350 W Thomas Road, Phoenix, AZ, 85013, USA
| | - Rita Sattler
- Department of Neurobiology, Barrow Neurological Institute, 350 W Thomas Road, Phoenix, AZ, 85013, USA.
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8
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Abstract
In eukaryotes, the separation of translation from transcription by the nuclear envelope enables mRNA modifications such as capping, splicing, and polyadenylation. These modifications are mediated by a spectrum of ribonuclear proteins that associate with preRNA transcripts, coordinating the different steps and coupling them to nuclear export, ensuring that only mature transcripts reach the cytoplasmic translation machinery. Although the components of this machinery have been identified and considerable functional insight has been achieved, a number of questions remain outstanding about mRNA nuclear export and how it is integrated into the nuclear phase of the gene expression pathway. Nuclear export factors mediate mRNA transit through nuclear pores to the cytoplasm, after which these factors are removed from the mRNA, preventing transcripts from returning to the nucleus. However, as outlined in this review, several aspects of the mechanism by which transport factor binding and release are mediated remain unclear, as are the roles of accessory nuclear components in these processes. Moreover, the mechanisms by which completion of mRNA splicing and polyadenylation are recognized, together with how they are coordinated with nuclear export, also remain only partially characterized. One attractive hypothesis is that dissociating poly(A) polymerase from the cleavage and polyadenylation machinery could signal completion of mRNA maturation and thereby provide a mechanism for initiating nuclear export. The impressive array of genetic, molecular, cellular, and structural data that has been generated about these systems now provides many of the tools needed to define the precise mechanisms involved in these processes and how they are integrated.
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Affiliation(s)
- Murray Stewart
- From the MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, United Kingdom
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9
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Abstract
The Three prime repair exonuclease 2 (TREX-2) complex functions as a platform to which many of the components of the nuclear mRNA processing machinery bind, facilitating integration of this phase of the gene expression pathway, as well as mediating the re-positioning of highly regulated actively transcribing genes (such as GAL1) to nuclear pores (NPCs) to accelerate their activation. In Saccharomyces cerevisiae the TREX-2 complex is based on a Sac3 scaffold to which Thp1, Sem1, Cdc31 and two Sus1 chains are bound. A combination of X-ray crystallography and electron microscopy studies have established the structure of two major regions of this complex: the M-region that functions to bind nucleic acids and the CID region that functions to link the complex to nuclear pores. These structures have facilitated the engineering of mutants that have been used to define the contributions made by the TREX-2 complex to locating high-expressed genes to nuclear pores and the contributions made to mRNA nuclear export.
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Affiliation(s)
- Murray Stewart
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, CB2 0QH, UK.
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10
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Boehringer A, Bowser R. RNA Nucleocytoplasmic Transport Defects in Neurodegenerative Diseases. ADVANCES IN NEUROBIOLOGY 2018; 20:85-101. [PMID: 29916017 DOI: 10.1007/978-3-319-89689-2_4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
In eukaryotic cells, transcription and translation are compartmentalized by the nuclear membrane, requiring an active transport of RNA from the nucleus into the cytoplasm. This is accomplished by a variety of transport complexes that contain either a member of the exportin family of proteins and translocation fueled by GTP hydrolysis or in the case of mRNA by complexes containing the export protein NXF1. Recent evidence indicates that RNA transport is altered in a number of different neurodegenerative diseases including Huntington's disease, Alzheimer's disease, frontotemporal dementia, and amyotrophic lateral sclerosis. Alterations in RNA transport predominately fall into three categories: Alterations in the nuclear membrane and mislocalization and aggregation of the nucleoporins that make up the nuclear pore; alterations in the Ran gradient and the proteins that control it which impacts exportin based nuclear export; and alterations of proteins that are required for the export of mRNA leading nuclear accumulation of mRNA.
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Affiliation(s)
- Ashley Boehringer
- Department of Neurobiology, Barrow Neurological Institute, Phoenix, AZ, USA.,School of Life Sciences, Arizona State University, Phoenix, AZ, USA
| | - Robert Bowser
- Department of Neurobiology, Barrow Neurological Institute, Phoenix, AZ, USA.
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11
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Evangelista FM, Maglott-Roth A, Stierle M, Brino L, Soutoglou E, Tora L. Transcription and mRNA export machineries SAGA and TREX-2 maintain monoubiquitinated H2B balance required for DNA repair. J Cell Biol 2018; 217:3382-3397. [PMID: 30054449 PMCID: PMC6168256 DOI: 10.1083/jcb.201803074] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 06/19/2018] [Accepted: 06/28/2018] [Indexed: 11/22/2022] Open
Abstract
The SAGA coactivator complex and the nuclear pore–associated TREX-2 complex couple transcription with mRNA export. Evangelista et al. identify a novel interplay between TREX-2 and the deubiquitination module of SAGA that is necessary to maintain monoubiquitinated H2B levels required for efficient DNA repair through homologous recombination. DNA repair is critical to maintaining genome integrity, and its dysfunction can cause accumulation of unresolved damage that leads to genomic instability. The Spt–Ada–Gcn5 acetyltransferase (SAGA) coactivator complex and the nuclear pore–associated transcription and export complex 2 (TREX-2) couple transcription with mRNA export. In this study, we identify a novel interplay between human TREX-2 and the deubiquitination module (DUBm) of SAGA required for genome stability. We find that the scaffold subunit of TREX-2, GANP, positively regulates DNA repair through homologous recombination (HR). In contrast, DUBm adaptor subunits ENY2 and ATXNL3 are required to limit unscheduled HR. These opposite roles are achieved through monoubiquitinated histone H2B (H2Bub1). Interestingly, the activity of the DUBm of SAGA on H2Bub1 is dependent on the integrity of the TREX-2 complex. Thus, we describe the existence of a functional interaction between human TREX-2 and SAGA DUBm that is key to maintaining the H2B/HB2ub1 balance needed for efficient repair and HR.
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Affiliation(s)
- Federica M Evangelista
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France.,Centre National de la Recherche Scientifique, UMR7104, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France.,Université de Strasbourg, Illkirch, France
| | - Anne Maglott-Roth
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France.,Centre National de la Recherche Scientifique, UMR7104, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France.,Université de Strasbourg, Illkirch, France
| | - Matthieu Stierle
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France.,Centre National de la Recherche Scientifique, UMR7104, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France.,Université de Strasbourg, Illkirch, France
| | - Laurent Brino
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France.,Centre National de la Recherche Scientifique, UMR7104, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France.,Université de Strasbourg, Illkirch, France
| | - Evi Soutoglou
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France .,Centre National de la Recherche Scientifique, UMR7104, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France.,Université de Strasbourg, Illkirch, France
| | - László Tora
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France .,Centre National de la Recherche Scientifique, UMR7104, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France.,Université de Strasbourg, Illkirch, France
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12
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Popova VV, Glukhova AA, Georgieva SG, Kopytova DV. Interactions of the TREX-2 complex with mRNP particle of β-tubulin 56D gene. Mol Biol 2016. [DOI: 10.1134/s0026893316060157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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13
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Kopytova D, Popova V, Kurshakova M, Shidlovskii Y, Nabirochkina E, Brechalov A, Georgiev G, Georgieva S. ORC interacts with THSC/TREX-2 and its subunits promote Nxf1 association with mRNP and mRNA export in Drosophila. Nucleic Acids Res 2016; 44:4920-33. [PMID: 27016737 PMCID: PMC4889942 DOI: 10.1093/nar/gkw192] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Accepted: 03/11/2016] [Indexed: 12/20/2022] Open
Abstract
The origin recognition complex (ORC) of eukaryotes associates with the replication origins and initiates the pre-replication complex assembly. In the literature, there are several reports of interaction of ORC with different RNAs. Here, we demonstrate for the first time a direct interaction of ORC with the THSC/TREX-2 mRNA nuclear export complex. The THSC/TREX-2 was purified from the Drosophila embryonic extract and found to bind with a fraction of the ORC. This interaction occurred via several subunits and was essential for Drosophila viability. Also, ORC was associated with mRNP, which was facilitated by TREX-2. ORC subunits interacted with the Nxf1 receptor mediating the bulk mRNA export. The knockdown of Orc5 led to a drop in the Nxf1 association with mRNP, while Orc3 knockdown increased the level of mRNP-bound Nxf1. The knockdown of Orc5, Orc3 and several other ORC subunits led to an accumulation of mRNA in the nucleus, suggesting that ORC participates in the regulation of the mRNP export.
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Affiliation(s)
- Daria Kopytova
- Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia
| | - Varvara Popova
- Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia
| | - Maria Kurshakova
- Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia
| | - Yulii Shidlovskii
- Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia
| | - Elena Nabirochkina
- Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia
| | - Alexander Brechalov
- Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia
| | - Georgii Georgiev
- Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia
| | - Sofia Georgieva
- Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia
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14
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Delaleau M, Borden KLB. Multiple Export Mechanisms for mRNAs. Cells 2015; 4:452-73. [PMID: 26343730 PMCID: PMC4588045 DOI: 10.3390/cells4030452] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 08/20/2015] [Accepted: 08/21/2015] [Indexed: 12/20/2022] Open
Abstract
Nuclear mRNA export plays an important role in gene expression. We describe the mechanisms of mRNA export including the importance of mRNP assembly, docking with the nuclear basket of the nuclear pore complex (NPC), transit through the central channel of the NPC and cytoplasmic release. We describe multiple mechanisms of mRNA export including NXF1 and CRM1 mediated pathways. Selective groups of mRNAs can be preferentially transported in order to respond to cellular stimuli. RNAs can be selected based on the presence of specific cis-acting RNA elements and binding of specific adaptor proteins. The role that dysregulation of this process plays in human disease is also discussed.
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Affiliation(s)
- Mildred Delaleau
- Department of Pathology and Cell Biology, Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, QC, H3C 3J7, Canada.
| | - Katherine L B Borden
- Department of Pathology and Cell Biology, Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, QC, H3C 3J7, Canada.
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15
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16
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Nuclear export of messenger RNA. Genes (Basel) 2015; 6:163-84. [PMID: 25836925 PMCID: PMC4488659 DOI: 10.3390/genes6020163] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 03/23/2015] [Accepted: 03/24/2015] [Indexed: 11/29/2022] Open
Abstract
Transport of messenger RNA (mRNA) from the nucleus to the cytoplasm is an essential step of eukaryotic gene expression. In the cell nucleus, a precursor mRNA undergoes a series of processing steps, including capping at the 5' ends, splicing and cleavage/polyadenylation at the 3' ends. During this process, the mRNA associates with a wide variety of proteins, forming a messenger ribonucleoprotein (mRNP) particle. Association with factors involved in nuclear export also occurs during transcription and processing, and thus nuclear export is fully integrated into mRNA maturation. The coupling between mRNA maturation and nuclear export is an important mechanism for providing only fully functional and competent mRNA to the cytoplasmic translational machinery, thereby ensuring accuracy and swiftness of gene expression. This review describes the molecular mechanism of nuclear mRNA export mediated by the principal transport factors, including Tap-p15 and the TREX complex.
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17
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Schnell SJ, Ma J, Yang W. Three-Dimensional Mapping of mRNA Export through the Nuclear Pore Complex. Genes (Basel) 2014; 5:1032-49. [PMID: 25393401 PMCID: PMC4276925 DOI: 10.3390/genes5041032] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Revised: 10/02/2014] [Accepted: 10/20/2014] [Indexed: 11/30/2022] Open
Abstract
The locations of transcription and translation of mRNA in eukaryotic cells are spatially separated by the nuclear envelope (NE). Plenty of nuclear pore complexes (NPCs) embedded in the NE function as the major gateway for the export of transcribed mRNAs from the nucleus to the cytoplasm. Whereas the NPC, perhaps one of the largest protein complexes, provides a relatively large channel for macromolecules to selectively pass through it in inherently three-dimensional (3D) movements, this channel is nonetheless below the diffraction limit of conventional light microscopy. A full understanding of the mRNA export mechanism urgently requires real-time mapping of the 3D dynamics of mRNA in the NPC of live cells with innovative imaging techniques breaking the diffraction limit of conventional light microscopy. Recently, super-resolution fluorescence microscopy and single-particle tracking (SPT) techniques have been applied to the study of nuclear export of mRNA in live cells. In this review, we emphasize the necessity of 3D mapping techniques in the study of mRNA export, briefly summarize the feasibility of current 3D imaging approaches, and highlight the new features of mRNA nuclear export elucidated with a newly developed 3D imaging approach combining SPT-based super-resolution imaging and 2D-to-3D deconvolution algorithms.
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Affiliation(s)
- Steven J Schnell
- Department of Biology, Temple University, Philadelphia, PA 19122, USA.
| | - Jiong Ma
- Department of Biology, Temple University, Philadelphia, PA 19122, USA.
| | - Weidong Yang
- Department of Biology, Temple University, Philadelphia, PA 19122, USA.
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Culjkovic-Kraljacic B, Borden KLB. Aiding and abetting cancer: mRNA export and the nuclear pore. Trends Cell Biol 2013; 23:328-35. [PMID: 23582887 DOI: 10.1016/j.tcb.2013.03.004] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2012] [Revised: 03/12/2013] [Accepted: 03/14/2013] [Indexed: 12/21/2022]
Abstract
mRNA export is a critical step in gene expression. Export of transcripts can be modulated in response to cellular signaling or stress. Consistently, mRNA export is dysregulated in primary human specimens derived from many different forms of cancer. Aberrant expression of export factors can alter the export of specific transcripts encoding proteins involved in proliferation, survival, and oncogenesis. These specific factors, which are not used for bulk mRNA export, are obvious therapeutic targets. Indeed, given the emerging role of mRNA export in cancer, it is not surprising that efforts to target different aspects of this pathway have reached the clinical trial stage. Thus, like transcription and translation, mRNA export may also play a critical role in cancer genesis and maintenance.
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Affiliation(s)
- Biljana Culjkovic-Kraljacic
- Institute for Research in Immunology and Cancer (IRIC), Department of Pathology and Cell Biology, Université de Montréal, Pavillion Marcelle-Coutu, Chemin Polytechnique, Montréal, Québec H3T 1J4, Canada
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Nuclear pore complex composition: a new regulator of tissue-specific and developmental functions. Nat Rev Mol Cell Biol 2013; 13:687-99. [PMID: 23090414 DOI: 10.1038/nrm3461] [Citation(s) in RCA: 259] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Nuclear pore complexes (NPCs) are multiprotein aqueous channels that penetrate the nuclear envelope connecting the nucleus and the cytoplasm. NPCs consist of multiple copies of roughly 30 different proteins known as nucleoporins (NUPs). Due to their essential role in controlling nucleocytoplasmic transport, NPCs have traditionally been considered as structures of ubiquitous composition. The overall structure of the NPC is indeed conserved in all cells, but new evidence suggests that the protein composition of NPCs varies among cell types and tissues. Moreover, mutations in various nucleoporins result in tissue-specific diseases. These findings point towards a heterogeneity in NPC composition and function. This unexpected heterogeneity suggests that cells use a combination of different nucleoporins to assemble NPCs with distinct properties and specialized functions.
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García-Oliver E, García-Molinero V, Rodríguez-Navarro S. mRNA export and gene expression: the SAGA-TREX-2 connection. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2011; 1819:555-65. [PMID: 22178374 DOI: 10.1016/j.bbagrm.2011.11.011] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Revised: 11/29/2011] [Accepted: 11/30/2011] [Indexed: 01/07/2023]
Abstract
In the gene expression field, different steps have been traditionally viewed as discrete and unconnected events. Nowadays, genetic and functional studies support the model of a coupled network of physical and functional connections to carry out mRNA biogenesis. Gene expression is a coordinated process that comprises different linked steps like transcription, RNA processing, export to the cytoplasm, translation and degradation of mRNAs. Its regulation is essential for cellular survival and can occur at many different levels. Transcription is the central function that occurs in the nucleus, and RNAPII plays an essential role in mRNA biogenesis. During transcription, nascent mRNA is associated with the mRNA-binding proteins involved in processing and export of the mRNA particle. Cells have developed a network of multi-protein complexes whose functions regulate the different factors involved both temporally and spatially. This coupling mechanism acts as a quality control to solve some of the organization problems of gene expression in vivo, where all the factors implicated ensure that mRNAs are ready to be exported and translated. In this review, we focus on the functional coupling of gene transcription and mRNA export, and place particular emphasis on the relationship between the NPC-associated complex, TREX2, and the transcription co-activator, SAGA. We have pinpointed the experimental evidence for Sus1's roles in transcription initiation, transcription elongation and mRNA export. In addition, we have reviewed other NPC-related processes such as gene gating to the nuclear envelope, the chromatin structure and the cellular context in which these processes take place. This article is part of a Special Issue entitled: Nuclear Transport and RNA Processing.
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Affiliation(s)
- Encar García-Oliver
- Centro de Investigación Príncipe Felipe (CIPF), Gene Expression coupled with RNA Transport Laboratory, Valencia, Spain
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