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Goswami R, Gupta A, Bednova O, Coulombe G, Patel D, Rotello VM, Leyton JV. Nuclear localization signal-tagged systems: relevant nuclear import principles in the context of current therapeutic design. Chem Soc Rev 2024; 53:204-226. [PMID: 38031452 PMCID: PMC10798298 DOI: 10.1039/d1cs00269d] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2023]
Abstract
Nuclear targeting of therapeutics provides a strategy for enhancing efficacy of molecules active in the nucleus and minimizing off-target effects. 'Active' nuclear-directed transport and efficient translocations across nuclear pore complexes provide the most effective means of maximizing nuclear localization. Nuclear-targeting systems based on nuclear localization signal (NLS) motifs have progressed significantly since the beginning of the current millennium. Here, we offer a roadmap for understanding the basic mechanisms of nuclear import in the context of actionable therapeutic design for developing NLS-therapeutics with improved treatment efficacy.
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Affiliation(s)
- Ritabrita Goswami
- Department of Chemistry, University of Massachusetts, Massachusetts, USA.
| | - Aarohi Gupta
- Department of Chemistry, University of Massachusetts, Massachusetts, USA.
| | - Olga Bednova
- Département de médecine nucléaire et radiobiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Québec, Canada
| | - Gaël Coulombe
- Service des stages et du développement professionnel, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Dipika Patel
- Service des stages et du développement professionnel, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Vincent M Rotello
- Department of Chemistry, University of Massachusetts, Massachusetts, USA.
| | - Jeffrey V Leyton
- École des sciences pharmaceutiques, Université d'Ottawa, Ottawa, Ontario, Canada.
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
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2
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Jamal QMS, Alharbi AH. Molecular docking and dynamics studies of cigarette smoke carcinogens interacting with acetylcholinesterase and butyrylcholinesterase enzymes of the central nervous system. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:61972-61992. [PMID: 34382170 DOI: 10.1007/s11356-021-15269-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Accepted: 06/28/2021] [Indexed: 06/13/2023]
Abstract
The free radicals produced by cigarette smoking are responsible for tissue damage, heart and lung diseases, and carcinogenesis. The effect of tobacco on the central nervous system (CNS) has received increased attention nowadays in research. Therefore, to explore the molecular interaction of cigarette smoke carcinogens (CSC) 4-(methylnitrosamine)-1-(3-pyridyl)-1-butanol (NNAL), 4-(methylnitrosamine)-1-(3-pyridyl)-1-butanone (NNK), and N'-nitrosonornicotine (NNN) with well-known targets of CNS-related disorders, acetylcholinesterase (AChE), and butyrylcholinesterase (BuChE) enzymes, a cascade of the computational study was conducted including molecular docking and molecular dynamics simulations (MDS). The investigated results of NNAL+AChEcomplex, NNK+AChEcomplex, and NNK+BuChEcomplex based on intermolecular energies (∆G) were found to -8.57 kcal/mol, -8.21 kcal/mol, and -8.08 kcal/mol, respectively. MDS deviation and fluctuation plots of the NNAL and NNK interaction with AChE and BuChE have shown significant results. Further, Molecular Mechanics Poisson-Boltzmann Surface Area (MM-PBSA) results shown the best total binding energy (Binding∆G) -87.381 (+/-13.119) kJ/mol during NNK interaction with AChE. Our study suggests that CSC is well capable of altering the normal biomolecular mechanism of CNS; thus, obtained data could be useful to design extensive wet laboratory experimentation to know the effects of CSC on human CNS.
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Affiliation(s)
- Qazi Mohammad Sajid Jamal
- Department of Health Informatics, College of Public Health and Health Informatics, Qassim University, Al Bukayriyah, Saudi Arabia.
| | - Ali H Alharbi
- Department of Health Informatics, College of Public Health and Health Informatics, Qassim University, Al Bukayriyah, Saudi Arabia
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3
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Coyne AN, Rothstein JD. Nuclear pore complexes - a doorway to neural injury in neurodegeneration. Nat Rev Neurol 2022; 18:348-362. [PMID: 35488039 PMCID: PMC10015220 DOI: 10.1038/s41582-022-00653-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/23/2022] [Indexed: 12/13/2022]
Abstract
The genetic underpinnings and end-stage pathological hallmarks of neurodegenerative diseases are increasingly well defined, but the cellular pathophysiology of disease initiation and propagation remains poorly understood, especially in sporadic forms of these diseases. Altered nucleocytoplasmic transport is emerging as a prominent pathomechanism of multiple neurodegenerative diseases, including amyotrophic lateral sclerosis, Alzheimer disease, frontotemporal dementia and Huntington disease. The nuclear pore complex (NPC) and interactions between its individual nucleoporin components and nuclear transport receptors regulate nucleocytoplasmic transport, as well as genome organization and gene expression. Specific nucleoporin abnormalities have been identified in sporadic and familial forms of neurodegenerative disease, and these alterations are thought to contribute to disrupted nucleocytoplasmic transport. The specific nucleoporins and nucleocytoplasmic transport proteins that have been linked to different neurodegenerative diseases are partially distinct, suggesting that NPC injury contributes to the cellular specificity of neurodegenerative disease and could be an early initiator of the pathophysiological cascades that underlie neurodegenerative disease. This concept is consistent with the fact that rare genetic mutations in some nucleoporins cause cell-type-specific neurological disease. In this Review, we discuss nucleoporin and NPC disruptions and consider their impact on cellular function and the pathophysiology of neurodegenerative disease.
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Affiliation(s)
- Alyssa N Coyne
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA. .,Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| | - Jeffrey D Rothstein
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA. .,Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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4
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Invasion and Propagation of White Spot Syndrome Virus: Hijacking of the Cytoskeleton, Intracellular Transport Machinery, and Nuclear Import Transporters. J Virol 2022; 96:e0220521. [PMID: 35638850 DOI: 10.1128/jvi.02205-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The pathogenesis of white spot syndrome virus (WSSV) is largely unclear. In this study, we found that actin nucleation and clathrin-mediated endocytosis were recruited for internalization of WSSV into crayfish hematopoietic tissue (Hpt) cells. This internalization was followed by intracellular transport of the invading virions via endocytic vesicles and endosomes. After envelope fusion within endosomes, the penetrated nucleocapsids were transported along microtubules toward the periphery of the nuclear pores. Furthermore, the nuclear transporter CqImportin α1/β1, via binding of ARM repeat domain within CqImportin α1 to the nuclear localization sequences (NLSs) of viral cargoes and binding of CqImportin β1 to the nucleoporins CqNup35/62 with the action of CqRan for docking to nuclear pores, was hijacked for both targeting of the incoming nucleocapsids toward the nuclear pores and import of the expressed viral structural proteins containing NLS into the cell nucleus. Intriguingly, dysfunction of CqImportin α1/β1 resulted in significant accumulation of incoming nucleocapsids on the periphery of the Hpt cell nucleus, leading to substantially decreased introduction of the viral genome into the nucleus and remarkably reduced nuclear import of expressed viral structural proteins with NLS; both of these effects were accompanied by significantly inhibited viral propagation. Accordingly, the survival rate of crayfish post-WSSV challenge was significantly increased after dysfunction of CqImportin α1/β1, also showing significantly reduced viral propagation, and was induced either by gene silencing or by pharmacological blockade via dietary administration of ivermectin per os. Collectively, our findings improve our understanding of WSSV pathogenesis and support future antiviral designing against WSSV. IMPORTANCE As one of the largest animal DNA viruses, white spot syndrome virus (WSSV) has been causing severe economical loss in aquaculture due to the limited knowledge on WSSV pathogenesis for an antiviral strategy. We demonstrate that the actin cytoskeleton, endocytic vesicles, endosomes, and microtubules are hijacked for WSSV invasion; importantly, the nuclear transporter CqImportin α1/β1 together with CqRan were recruited, via binding of CqImportin β1 to the nucleoporins CqNup35/62, for both the nuclear pore targeting of the incoming nucleocapsids and the nuclear import of expressed viral structural proteins containing the nuclear localization sequences (NLSs). This is the first report that NLSs from both viral structure proteins and host factor are elaborately recruited together to facilitate WSSV infection. Our findings provide a novel explanation for WSSV pathogenesis involving systemic hijacking of host factors, which can be used for antiviral targeting against WSSV disease, such as the blockade of CqImportin α1/β1 with ivermectin.
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Functional Characterization of an In-Frame Deletion in the Basic Domain of the Retinal Transcription Factor ATOH7. Int J Mol Sci 2022; 23:ijms23031053. [PMID: 35162975 PMCID: PMC8834682 DOI: 10.3390/ijms23031053] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 01/12/2022] [Accepted: 01/14/2022] [Indexed: 02/01/2023] Open
Abstract
Basic helix–loop–helix (bHLH) transcription factors are evolutionarily conserved and structurally similar proteins important in development. The temporospatial expression of atonal bHLH transcription factor 7 (ATOH7) directs the differentiation of retinal ganglion cells and mutations in the human gene lead to vitreoretinal and/or optic nerve abnormalities. Characterization of pathogenic ATOH7 mutations is needed to understand the functions of the conserved bHLH motif. The published ATOH7 in-frame deletion p.(Arg41_Arg48del) removes eight highly conserved amino acids in the basic domain. We functionally characterized the mutant protein by expressing V5-tagged ATOH7 constructs in human embryonic kidney 293T (HEK293T) cells for subsequent protein analyses, including Western blot, cycloheximide chase assays, Förster resonance energy transfer fluorescence lifetime imaging, enzyme-linked immunosorbent assays and dual-luciferase assays. Our results indicate that the in-frame deletion in the basic domain causes mislocalization of the protein, which can be rescued by a putative dimerization partner transcription factor 3 isoform E47 (E47), suggesting synergistic nuclear import. Furthermore, we observed (i) increased proteasomal degradation of the mutant protein, (ii) reduced protein heterodimerization, (iii) decreased DNA-binding and transcriptional activation of a reporter gene, as well as (iv) inhibited E47 activity. Altogether our observations suggest that the DNA-binding basic domain of ATOH7 has additional roles in regulating the nuclear import, dimerization, and protein stability.
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6
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Liu X, Chen J, Long X, Lan J, Liu X, Zhou M, Zhang S, Zhou J. RSL1D1 promotes the progression of colorectal cancer through RAN-mediated autophagy suppression. Cell Death Dis 2022; 13:43. [PMID: 35013134 PMCID: PMC8748816 DOI: 10.1038/s41419-021-04492-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 12/02/2021] [Accepted: 12/14/2021] [Indexed: 01/18/2023]
Abstract
RSL1D1 (ribosomal L1 domain containing 1), a member of the universal ribosomal protein uL1 family, was suggested to be a new candidate target for colorectal cancer (CRC). However, the role of RSL1D1 in cancer, including CRC, remains largely elusive. Here, we demonstrated that RSL1D1 expression was significantly elevated in tumors from CRC patients and that high expression of RSL1D1 was correlated with poorer survival of CRC patients. Functionally, RSL1D1 promoted the proliferation, invasion, and metastasis of CRC cells by suppressing autophagy. Interestingly, RSL1D1 interacted with RAN and inhibited its deacetylation by competitively binding with Sirt7. By affecting the acetylation of RAN, RSL1D1 inhibited the accumulation of nuclear STAT3 and the STAT3-regulated autophagic program. Taken together, our study uncovered the key role of the RSL1D1/RAN/STAT3 regulatory axis in autophagy and tumor progression in CRC, providing a new candidate target for CRC treatment.
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Affiliation(s)
- Xunhua Liu
- grid.284723.80000 0000 8877 7471Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515 China ,grid.284723.80000 0000 8877 7471Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515 China
| | - Jianxiong Chen
- grid.284723.80000 0000 8877 7471Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515 China ,grid.284723.80000 0000 8877 7471Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515 China
| | - Xiaoli Long
- grid.284723.80000 0000 8877 7471Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515 China ,grid.284723.80000 0000 8877 7471Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515 China
| | - Jiawen Lan
- grid.284723.80000 0000 8877 7471Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515 China ,grid.284723.80000 0000 8877 7471Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515 China
| | - Xiaoting Liu
- grid.284723.80000 0000 8877 7471Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515 China ,grid.284723.80000 0000 8877 7471Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515 China
| | - Miao Zhou
- grid.284723.80000 0000 8877 7471Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515 China
| | - Sijing Zhang
- grid.284723.80000 0000 8877 7471Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515 China
| | - Jun Zhou
- Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China. .,Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China.
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Sinsky J, Pichlerova K, Hanes J. Tau Protein Interaction Partners and Their Roles in Alzheimer's Disease and Other Tauopathies. Int J Mol Sci 2021; 22:9207. [PMID: 34502116 PMCID: PMC8431036 DOI: 10.3390/ijms22179207] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 08/23/2021] [Accepted: 08/25/2021] [Indexed: 02/06/2023] Open
Abstract
Tau protein plays a critical role in the assembly, stabilization, and modulation of microtubules, which are important for the normal function of neurons and the brain. In diseased conditions, several pathological modifications of tau protein manifest. These changes lead to tau protein aggregation and the formation of paired helical filaments (PHF) and neurofibrillary tangles (NFT), which are common hallmarks of Alzheimer's disease and other tauopathies. The accumulation of PHFs and NFTs results in impairment of physiological functions, apoptosis, and neuronal loss, which is reflected as cognitive impairment, and in the late stages of the disease, leads to death. The causes of this pathological transformation of tau protein haven't been fully understood yet. In both physiological and pathological conditions, tau interacts with several proteins which maintain their proper function or can participate in their pathological modifications. Interaction partners of tau protein and associated molecular pathways can either initiate and drive the tau pathology or can act neuroprotective, by reducing pathological tau proteins or inflammation. In this review, we focus on the tau as a multifunctional protein and its known interacting partners active in regulations of different processes and the roles of these proteins in Alzheimer's disease and tauopathies.
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Affiliation(s)
| | | | - Jozef Hanes
- Institute of Neuroimmunology, Slovak Academy of Sciences, Dubravska Cesta 9, 845 10 Bratislava, Slovakia; (J.S.); (K.P.)
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Kashif M, Bharati AP, Chaturvedi SK, Khan RH, Ahmad A, Kumar B, Zamzami MA, Ahmad V, Kumari S. pH and alcohol induced structural transition in Ntf2 a nuclear transport factor of Saccharomyces cerevisiae. Int J Biol Macromol 2020; 159:79-86. [PMID: 32407943 DOI: 10.1016/j.ijbiomac.2020.05.056] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 05/07/2020] [Accepted: 05/08/2020] [Indexed: 10/24/2022]
Abstract
Ntf2 is a nuclear envelope protein, which play a pivotal role in nucleocytoplasmic transport and mediates the nuclear import of RanGDP. It interacts with various nucleoporins along with Ran-GDP and part of a multicomponent system that assembles at the nuclear pore complex (NCP) during nuclear import. Here, we have described the biophysical characterization of Ntf2 from Saccharomyces cerevisiae. Recombinant Ntf2 showed increment in the β-sheet content as well as decrement in the α-helix content from pH-7.0 to pH-4.0. A subsequent decrease in the pH led to increment in the α-helical content along with decrement in β-sheet content. Intrinsic fluorescence studies demonstrated the unfolding of the protein below physiological pH. Ntf2 showed stabilization as well as phenomenal phase transition (β sheet to α helix) by increase in alcohol concentration from 10% to 70%. Further increase in alcohol concentration (90%) resulted in residual secondary structure in Ntf2 protein. Presence of ammonium sulfate also stabilizes the secondary structure of Ntf2 protein. The structural characterization reveals the flexibility and the stability of Ntf2 at various conditions. These structural alterations in Ntf2 protein probably occurs in the course of nucleocytoplasmic transport when it interacts with other proteins moving towards its final destination.
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Affiliation(s)
- Mohd Kashif
- Center for Plant Molecular Biology Division, CSIR-NBRI, Lucknow, India.
| | | | | | - Rizwan Hasan Khan
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh, India
| | - Abrar Ahmad
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia.
| | - Bhupendra Kumar
- Center for Plant Molecular Biology Division, CSIR-NBRI, Lucknow, India
| | - Mazin A Zamzami
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Varish Ahmad
- Department of Health and Information Technology, Faculty of Applied Studies, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Sunita Kumari
- ICAR-Indian Institute of Seed Science, Mau, Uttar Pradesh 275103, India
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9
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Sinsky J, Majerova P, Kovac A, Kotlyar M, Jurisica I, Hanes J. Physiological Tau Interactome in Brain and Its Link to Tauopathies. J Proteome Res 2020; 19:2429-2442. [PMID: 32357304 DOI: 10.1021/acs.jproteome.0c00137] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Alzheimer's disease (AD) and most of the other tauopathies are incurable neurodegenerative diseases with unpleasant symptoms and consequences. The common hallmark of all of these diseases is tau pathology, but its connection with disease progress has not been completely understood so far. Therefore, uncovering novel tau-interacting partners and pathology affected molecular pathways can reveal the causes of diseases as well as potential targets for the development of AD treatment. Despite the large number of known tau-interacting partners, a limited number of studies focused on in vivo tau interactions in disease or healthy conditions are available. Here, we applied an in vivo cross-linking approach, capable of capturing weak and transient protein-protein interactions, to a unique transgenic rat model of progressive tau pathology similar to human AD. We have identified 175 potential novel and known tau-interacting proteins by MALDI-TOF mass spectrometry. Several of the most promising candidates for possible drug development were selected for validation by coimmunoprecipitation and colocalization experiments in animal and cellular models. Three proteins, Baiap2, Gpr37l1, and Nptx1, were confirmed as novel tau-interacting partners, and on the basis of their known functions and implications in neurodegenerative or psychiatric disorders, we proposed their potential role in tau pathology.
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Affiliation(s)
- Jakub Sinsky
- Institute of Neuroimmunology, Slovak Academy of Sciences, Dubravska cesta 9, Bratislava 84510, Slovakia
| | - Petra Majerova
- Institute of Neuroimmunology, Slovak Academy of Sciences, Dubravska cesta 9, Bratislava 84510, Slovakia.,AXON Neuroscience R&D Services SE, Dvorakovo nabrezie 10, Bratislava 811 02, Slovakia
| | - Andrej Kovac
- Institute of Neuroimmunology, Slovak Academy of Sciences, Dubravska cesta 9, Bratislava 84510, Slovakia.,AXON Neuroscience R&D Services SE, Dvorakovo nabrezie 10, Bratislava 811 02, Slovakia
| | - Max Kotlyar
- Krembil Research Institute, UHN, 60 Leonard Avenue, Toronto, Ontario M5T 0S8, Canada
| | - Igor Jurisica
- Institute of Neuroimmunology, Slovak Academy of Sciences, Dubravska cesta 9, Bratislava 84510, Slovakia.,Krembil Research Institute, UHN, 60 Leonard Avenue, Toronto, Ontario M5T 0S8, Canada.,Departments of Medical Biophysics and Computer Science, University of Toronto, 27 King's College Circle, Toronto, Ontario ON M5S, Canada
| | - Jozef Hanes
- Institute of Neuroimmunology, Slovak Academy of Sciences, Dubravska cesta 9, Bratislava 84510, Slovakia.,AXON Neuroscience R&D Services SE, Dvorakovo nabrezie 10, Bratislava 811 02, Slovakia
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10
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Swale C, Da Costa B, Sedano L, Garzoni F, McCarthy AA, Berger I, Bieniossek C, Ruigrok RWH, Delmas B, Crépin T. X-ray Structure of the Human Karyopherin RanBP5, an Essential Factor for Influenza Polymerase Nuclear Trafficking. J Mol Biol 2020; 432:3353-3359. [PMID: 32222384 DOI: 10.1016/j.jmb.2020.03.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 03/16/2020] [Accepted: 03/22/2020] [Indexed: 12/15/2022]
Abstract
Here, we describe the crystal structures of two distinct isoforms of ligand-free human karyopherin RanBP5 and investigate its global propensity to interact with influenza A virus polymerase. Our results confirm the general architecture and mechanism of the IMB3 karyopherin-β subfamily whilst also highlighting differences with the yeast orthologue Kap121p. Moreover, our results provide insight into the structural flexibility of β-importins in the unbound state. Based on docking of a nuclear localisation sequence, point mutations were designed, which suppress influenza PA-PB1 subcomplex binding to RanBP5 in a binary protein complementation assay.
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Affiliation(s)
- Christopher Swale
- Institut de Biologie Structurale (IBS), University Grenoble Alpes, CEA, CNRS, 38044 Grenoble, France; EMBL Grenoble Outstation, 71 Avenue des Martyrs, BP181, F-38042 Grenoble Cedex 9, France
| | - Bruno Da Costa
- Virologie et Immunologie Moléculaires, INRA, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Laura Sedano
- Virologie et Immunologie Moléculaires, INRA, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Frédéric Garzoni
- EMBL Grenoble Outstation, 71 Avenue des Martyrs, BP181, F-38042 Grenoble Cedex 9, France
| | - Andrew A McCarthy
- EMBL Grenoble Outstation, 71 Avenue des Martyrs, BP181, F-38042 Grenoble Cedex 9, France
| | - Imre Berger
- EMBL Grenoble Outstation, 71 Avenue des Martyrs, BP181, F-38042 Grenoble Cedex 9, France; Max Planck Centre for Minimal Biology, University of Bristol, Clifton BS8 1TD, United Kingdom
| | - Christoph Bieniossek
- Roche Innovation Centre, Basel, Switzerland F. Hoffmann-La Roche AG, Grenzacherstrasse 124, CH-4070 Basel, Switzerland
| | - Rob W H Ruigrok
- Institut de Biologie Structurale (IBS), University Grenoble Alpes, CEA, CNRS, 38044 Grenoble, France
| | - Bernard Delmas
- Virologie et Immunologie Moléculaires, INRA, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Thibaut Crépin
- Institut de Biologie Structurale (IBS), University Grenoble Alpes, CEA, CNRS, 38044 Grenoble, France.
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11
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Barbato S, Kapinos LE, Rencurel C, Lim RYH. Karyopherin enrichment at the nuclear pore complex attenuates Ran permeability. J Cell Sci 2020; 133:jcs238121. [PMID: 31932502 DOI: 10.1242/jcs.238121] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Accepted: 12/13/2019] [Indexed: 12/25/2022] Open
Abstract
Ran is a small GTPase whose nucleotide-bound forms cycle through nuclear pore complexes (NPCs) to direct nucleocytoplasmic transport (NCT). Generally, Ran guanosine triphosphate (RanGTP) binds cargo-carrying karyopherin receptors (Kaps) in the nucleus and releases them into the cytoplasm following hydrolysis to Ran guanosine diphosphate (RanGDP). This generates a remarkably steep Ran gradient across the nuclear envelope that sustains compartment-specific cargo delivery and accumulation. However, because NPCs are permeable to small molecules of comparable size, it is unclear how an uncontrolled mixing of RanGTP and RanGDP is prevented. Here, we find that an NPC-enriched pool of karyopherin subunit beta 1 (KPNB1, hereafter referred to as Kapβ1) selectively mediates Ran diffusion across the pore but not passive molecules of similar size (e.g. GFP). This is due to RanGTP having a stronger binding interaction with Kapβ1 than RanGDP. For this reason, the RanGDP importer, nuclear transport factor 2, facilitates the return of RanGDP into the nucleus following GTP hydrolysis. Accordingly, the enrichment of Kapβ1 at NPCs may function as a retention mechanism that preserves the sharp transition of RanGTP and RanGDP in the nucleus and cytoplasm, respectively.
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Affiliation(s)
- Suncica Barbato
- Biozentrum & The Swiss Nanoscience Institute, University of Basel, 4056 Basel, Switzerland
| | - Larisa E Kapinos
- Biozentrum & The Swiss Nanoscience Institute, University of Basel, 4056 Basel, Switzerland
| | - Chantal Rencurel
- Biozentrum & The Swiss Nanoscience Institute, University of Basel, 4056 Basel, Switzerland
| | - Roderick Y H Lim
- Biozentrum & The Swiss Nanoscience Institute, University of Basel, 4056 Basel, Switzerland
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12
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Lee KM, Wu CC, Wu SE, Lin YH, Wang LT, Chang CR, Huang PN, Shih SR, Kuo RL. The RNA-dependent RNA polymerase of enterovirus A71 associates with ribosomal proteins and positively regulates protein translation. RNA Biol 2020; 17:608-622. [PMID: 32009553 DOI: 10.1080/15476286.2020.1722448] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
Enteroviruses, which may cause neurological complications, have become a public health threat worldwide in recent years. Interactions between cellular proteins and enteroviral proteins could interfere with cellular biological processes to facilitate viral replication in infected cells. Enteroviral RNA-dependent RNA polymerase (RdRP), known as 3D protein, mainly functions as a replicase for viral RNA synthesis in infected cells. However, the 3D protein encoded by enterovirus A71 (EV-A71) could also interact with several cellular proteins to regulate cellular events and responses during infection. To globally investigate the functions of the EV-A71 3D protein in regulating biological processes in host cells, we performed immunoprecipitation coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) to identify host proteins that may associate with the 3D protein. We found that the 3D protein interacts with factors involved in translation-related biological processes, including ribosomal proteins. In addition, polysome profiling analysis showed that the 3D protein cosediments with small and large subunits of ribosomes. We further discovered that the EV-A71 3D protein could enhance EV-A71 internal ribosome entry site (IRES)-dependent translation as well as cap-dependent translation. Collectively, this research demonstrated that the RNA polymerase encoded by EV-A71 could join a functional ribosomal complex and positively regulate viral and host translation.
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Affiliation(s)
- Kuo-Ming Lee
- Research Center for Emerging Viral Infections, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Chih-Ching Wu
- Research Center for Emerging Viral Infections, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Department of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Department of Otolaryngology-Head & Neck Surgery, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan
| | - Shang-En Wu
- Department of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Ya-Han Lin
- Department of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Li-Ting Wang
- Research Center for Emerging Viral Infections, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Chun-Ru Chang
- Department of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Peng-Nien Huang
- Research Center for Emerging Viral Infections, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Shin-Ru Shih
- Research Center for Emerging Viral Infections, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Department of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Clinical Virology Laboratory, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan
| | - Rei-Lin Kuo
- Research Center for Emerging Viral Infections, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Department of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Division of Allergy, Asthma, and Rheumatology, Department of Pediatrics, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan
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13
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Tamura T, Takato M, Shiono K, Hamachi I. Development of a Photoactivatable Proximity Labeling Method for the Identification of Nuclear Proteins. CHEM LETT 2020. [DOI: 10.1246/cl.190804] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Tomonori Tamura
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Mikiko Takato
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Keiya Shiono
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Itaru Hamachi
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
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14
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Coppola U, Ristoratore F, Albalat R, D'Aniello S. The evolutionary landscape of the Rab family in chordates. Cell Mol Life Sci 2019; 76:4117-4130. [PMID: 31028425 PMCID: PMC11105323 DOI: 10.1007/s00018-019-03103-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 03/29/2019] [Accepted: 04/10/2019] [Indexed: 12/30/2022]
Abstract
Intracellular traffic amongst organelles represents a key feature for eukaryotes and is orchestrated principally by members of Rab family, the largest within Ras superfamily. Given that variations in Rab repertoire have been fundamental in animal diversification, we provided the most exhaustive survey regarding the Rab toolkit of chordates. Our findings reveal the existence of 42 metazoan conserved subfamilies exhibiting a univocal intron/exon structure preserved from cnidarians to vertebrates. Since the current view does not capture the Rab complexity, we propose a new Rab family classification in three distinct monophyletic clades. The Rab complement of chordates shows a dramatic diversification due to genome duplications and independent gene duplications and losses with sharp differences amongst cephalochordates, tunicates and gnathostome vertebrates. Strikingly, the analysis of the domain architecture of this family highlighted the existence of chimeric calcium-binding Rabs, which are animal novelties characterized by a complex evolutionary history in gnathostomes and whose role in cellular metabolism is obscure. This work provides novel insights in the knowledge of Rab family: our hypothesis is that chordates represent a hotspot of Rab variability, with many events of gene gains and losses impacting intracellular traffic capabilities. Our results help to elucidate the role of Rab members in the transport amongst endomembranes and shed light on intracellular traffic routes in vertebrates. Then, since the predominant role of Rabs in the molecular communication between different cellular districts, this study paves to way to comprehend inherited or acquired human disorders provoked by dysfunctions in Rab genes.
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Affiliation(s)
- Ugo Coppola
- Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn Napoli, Villa Comunale 1, 80121, Naples, Italy
- Molecular Cardiovascular Biology Division, Cincinnati Children's Hospital Medical Center, Cincinnati, USA
| | - Filomena Ristoratore
- Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn Napoli, Villa Comunale 1, 80121, Naples, Italy
| | - Ricard Albalat
- Departament de Genètica, Microbiologia i Estadística and Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Av. Diagonal 643, 08028, Barcelona, Spain.
| | - Salvatore D'Aniello
- Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn Napoli, Villa Comunale 1, 80121, Naples, Italy.
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15
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Zheng L, Nagar M, Maurais AJ, Slade DJ, Parelkar SS, Coonrod SA, Weerapana E, Thompson PR. Calcium Regulates the Nuclear Localization of Protein Arginine Deiminase 2. Biochemistry 2019; 58:3042-3056. [PMID: 31243954 DOI: 10.1021/acs.biochem.9b00225] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Protein arginine deiminases (PADs) are calcium-dependent enzymes that mediate the post-translational conversion of arginine into citrulline. Dysregulated PAD activity is associated with numerous autoimmune disorders and cancers. In breast cancer, PAD2 citrullinates histone H3R26 and activates the transcription of estrogen receptor target genes. However, PAD2 lacks a canonical nuclear localization sequence, and it is unclear how this enzyme is transported into the nucleus. Here, we show for the first time that PAD2 translocates into the nucleus in response to calcium signaling. Using BioID2, a proximity-dependent biotinylation method for identifying interacting proteins, we found that PAD2 preferentially associates with ANXA5 in the cytoplasm. Binding of calcium to PAD2 weakens this cytoplasmic interaction, which generates a pool of calcium-bound PAD2 that can interact with Ran. We hypothesize that this latter interaction promotes the translocation of PAD2 into the nucleus. These findings highlight a critical role for ANXA5 in regulating PAD2 and identify an unusual mechanism whereby proteins translocate between the cytosol and nucleus.
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Affiliation(s)
- Li Zheng
- Department of Biochemistry and Pharmacology , University of Massachusetts Medical School , Worcester , Massachusetts 01605 , United States.,Program in Chemical Biology , University of Massachusetts Medical School , 364 Plantation Street , Worcester , Massachusetts 01605 , United States
| | - Mitesh Nagar
- Department of Biochemistry and Pharmacology , University of Massachusetts Medical School , Worcester , Massachusetts 01605 , United States.,Program in Chemical Biology , University of Massachusetts Medical School , 364 Plantation Street , Worcester , Massachusetts 01605 , United States
| | - Aaron J Maurais
- Department of Chemistry , Boston College , Chestnut Hill , Massachusetts 02467 , United States
| | - Daniel J Slade
- Department of Biochemistry , Virginia Polytechnic Institute and State University , Blacksburg , Virginia 24061 , United States
| | - Sangram S Parelkar
- Department of Biochemistry and Pharmacology , University of Massachusetts Medical School , Worcester , Massachusetts 01605 , United States
| | - Scott A Coonrod
- James A. Baker Institute for Animal Health, College of Veterinary Medicine , Cornell University , Ithaca , New York 14853 , United States
| | - Eranthie Weerapana
- Department of Chemistry , Boston College , Chestnut Hill , Massachusetts 02467 , United States
| | - Paul R Thompson
- Department of Biochemistry and Pharmacology , University of Massachusetts Medical School , Worcester , Massachusetts 01605 , United States.,Program in Chemical Biology , University of Massachusetts Medical School , 364 Plantation Street , Worcester , Massachusetts 01605 , United States
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16
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Pappas SS, Liang CC, Kim S, Rivera CO, Dauer WT. TorsinA dysfunction causes persistent neuronal nuclear pore defects. Hum Mol Genet 2019; 27:407-420. [PMID: 29186574 DOI: 10.1093/hmg/ddx405] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 11/15/2017] [Indexed: 01/09/2023] Open
Abstract
A critical challenge to deciphering the pathophysiology of neurodevelopmental disease is identifying which of the myriad abnormalities that emerge during CNS maturation persist to contribute to long-term brain dysfunction. Childhood-onset dystonia caused by a loss-of-function mutation in the AAA+ protein torsinA exemplifies this challenge. Neurons lacking torsinA develop transient nuclear envelope (NE) malformations during CNS maturation, but no NE defects are described in mature torsinA null neurons. We find that during postnatal CNS maturation torsinA null neurons develop mislocalized and dysfunctional nuclear pore complexes (NPC) that lack NUP358, normally added late in NPC biogenesis. SUN1, a torsinA-related molecule implicated in interphase NPC biogenesis, also exhibits localization abnormalities. Whereas SUN1 and associated nuclear membrane abnormalities resolve in juvenile mice, NPC defects persist into adulthood. These findings support a role for torsinA function in NPC biogenesis during neuronal maturation and implicate altered NPC function in dystonia pathophysiology.
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Affiliation(s)
| | | | - Sumin Kim
- Cellular and Molecular Biology Program
| | | | - William T Dauer
- Department of Neurology.,Cellular and Molecular Biology Program.,Department of Cell and Developmental Biology.,VA Ann Arbor Health System, University of Michigan Medical School, Ann Arbor, MI 48109, USA
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17
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Coppola U, Caccavale F, Scelzo M, Holland ND, Ristoratore F, D’Aniello S. Ran GTPase, an eukaryotic gene novelty, is involved in amphioxus mitosis. PLoS One 2018; 13:e0196930. [PMID: 30300344 PMCID: PMC6177115 DOI: 10.1371/journal.pone.0196930] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 04/23/2018] [Indexed: 01/19/2023] Open
Abstract
Ran (ras-related nuclear protein) is a small GTPase belonging to the RAS superfamily that is specialized in nuclear trafficking. Through different accessory proteins, Ran plays key roles in several processes including nuclear import-export, mitotic progression and spindle assembly. Consequently, Ran dysfunction has been linked to several human pathologies. This work illustrates the high degree of amino acid conservation of Ran orthologues across evolution, reflected in its conserved role in nuclear trafficking. Moreover, we studied the evolutionary scenario of the pre-metazoan genetic linkage between Ran and Stx, and we hypothesized that chromosomal proximity of these two genes across metazoans could be related to a regulatory logic or a functional linkage. We studied, for the first time, Ran expression during amphioxus development and reported its presence in the neural vesicle, mouth, gill slits and gut corresponding to body regions involved in active cell division.
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Affiliation(s)
- Ugo Coppola
- Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn Napoli, Villa Comunale, Napoli, Italy
| | - Filomena Caccavale
- Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn Napoli, Villa Comunale, Napoli, Italy
| | - Marta Scelzo
- Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn Napoli, Villa Comunale, Napoli, Italy
- Laboratory of Developmental Biology of Villefranche sur Mer, UMR7009 CNRS/UPMC Observatoire Océanologique, Villefranche sur Mer, France
| | - Nicholas D. Holland
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California at San Diego, La Jolla, CA, United States of America
| | - Filomena Ristoratore
- Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn Napoli, Villa Comunale, Napoli, Italy
| | - Salvatore D’Aniello
- Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn Napoli, Villa Comunale, Napoli, Italy
- * E-mail:
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18
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Nuclear RIPK3 and MLKL contribute to cytosolic necrosome formation and necroptosis. Commun Biol 2018; 1:6. [PMID: 30271893 PMCID: PMC6123744 DOI: 10.1038/s42003-017-0007-1] [Citation(s) in RCA: 99] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 11/22/2017] [Indexed: 01/12/2023] Open
Abstract
Necroptotic signaling converges in the assembly of a cytosolic signaling platform, the necrosome, with the activation of its downstream effector, MLKL. RIPK1 and RIPK3, key components of the necrosome, act as signaling intermediates for the activation of MLKL. We report that RIPK3 and MLKL continuously shuttle between the nucleus and the cytoplasm, whereas RIPK1 is constitutively present in both compartments. During TNF-induced necroptosis, nuclear RIPK1 becomes ubiquitinated, after which nuclear MLKL becomes phosphorylated and oligomerized. Pharmacological inhibition of the nuclear export machinery leads to retention of RIPK3 and MLKL in the nucleus, prevents the nucleation of cytosolic RIPK3/MLKL oligomerization, and reduces cell death. Our results suggest that passage of necroptotic signaling components through the nucleus is a mechanism for regulating cytosolic necrosome formation and consequently necroptotic cell death. Kathrin Weber et al. report that the necrosome components RIPK3 and MLKL constitutively shuttle between the nucleus and cytoplasm. They find that increasing ratios of nuclear:cytosolic RIPK3 and MLKL prevents necrotic cell death, suggesting a mechanism by which the cell regulates necrosome formation and death.
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19
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Pawar S, Ungricht R, Tiefenboeck P, Leroux JC, Kutay U. Efficient protein targeting to the inner nuclear membrane requires Atlastin-dependent maintenance of ER topology. eLife 2017; 6:28202. [PMID: 28826471 PMCID: PMC5587084 DOI: 10.7554/elife.28202] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 08/13/2017] [Indexed: 01/06/2023] Open
Abstract
Newly synthesized membrane proteins are targeted to the inner nuclear membrane (INM) by diffusion within the membrane system of the endoplasmic reticulum (ER), translocation through nuclear pore complexes (NPCs) and retention on nuclear partners. Using a visual in vitro assay we previously showed that efficient protein targeting to the INM depends on nucleotide hydrolysis. We now reveal that INM targeting is GTP-dependent. Exploiting in vitro reconstitution and in vivo analysis of INM targeting, we establish that Atlastins, membrane-bound GTPases of the ER, sustain the efficient targeting of proteins to the INM by their continued activity in preserving ER topology. When ER topology is altered, the long-range diffusional exchange of proteins in the ER network and targeting efficiency to the INM are diminished. Highlighting the general importance of proper ER topology, we show that Atlastins also influence NPC biogenesis and timely exit of secretory cargo from the ER.
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Affiliation(s)
- Sumit Pawar
- Department of Biology, Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
| | - Rosemarie Ungricht
- Department of Biology, Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
| | - Peter Tiefenboeck
- Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, ETH Zurich, Zurich, Switzerland
| | - Jean-Christophe Leroux
- Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, ETH Zurich, Zurich, Switzerland
| | - Ulrike Kutay
- Department of Biology, Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
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20
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SUMOylation and calcium signalling: potential roles in the brain and beyond. Neuronal Signal 2017; 1:NS20160010. [PMID: 32714579 PMCID: PMC7373246 DOI: 10.1042/ns20160010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 07/10/2017] [Accepted: 07/11/2017] [Indexed: 12/23/2022] Open
Abstract
Small ubiquitin-like modifier (SUMO) conjugation (or SUMOylation) is a post-translational protein modification implicated in alterations to protein expression, localization and function. Despite a number of nuclear roles for SUMO being well characterized, this process has only started to be explored in relation to membrane proteins, such as ion channels. Calcium ion (Ca2+) signalling is crucial for the normal functioning of cells and is also involved in the pathophysiological mechanisms underlying relevant neurological and cardiovascular diseases. Intracellular Ca2+ levels are tightly regulated; at rest, most Ca2+ is retained in organelles, such as the sarcoplasmic reticulum, or in the extracellular space, whereas depolarization triggers a series of events leading to Ca2+ entry, followed by extrusion and reuptake. The mechanisms that maintain Ca2+ homoeostasis are candidates for modulation at the post-translational level. Here, we review the effects of protein SUMOylation, including Ca2+ channels, their proteome and other proteins associated with Ca2+ signalling, on vital cellular functions, such as neurotransmission within the central nervous system (CNS) and in additional systems, most prominently here, in the cardiac system.
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21
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Vijayaraghavan B, Jafferali MH, Figueroa RA, Hallberg E. Samp1, a RanGTP binding transmembrane protein in the inner nuclear membrane. Nucleus 2017; 7:415-23. [PMID: 27541860 PMCID: PMC5039005 DOI: 10.1080/19491034.2016.1220465] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Samp1 is a transmembrane protein of the inner nuclear membrane (INM), which interacts with the nuclear lamina and the Linker of Nucleoskeleton and Cytoskeleton (LINC) complex in interphase and during mitosis, it localizes to the mitotic spindle. Samp1 was recently found to coprecipitate a protein complex containing Ran, a GTPase with fundamental regulatory functions both in interphase and in mitosis. To investigate the interaction between Samp1 and Ran in further detail, we have designed and expressed recombinant fusion proteins of the Chaetomium thermophilum homolog of Samp1 (Ct.Samp1) and human Ran. Pulldown experiments show that Samp1 binds directly to Ran and that Samp1 binds better to RanGTP compared to RanGDP. Samp1 also preferred RanGTP over RanGDP in living tsBN2 cells. We also show that the Ran binding domain is located between amino acids 75–135 in the nucleoplasmically exposed N-terminal tail of Samp1. This domain is unique for Samp1, without homology in any other proteins in fungi or metazoa. Samp1 is the first known transmembrane protein that binds to Ran and could provide a unique local binding site for RanGTP in the INM. Samp1 overexpression resulted in increased Ran concentrations in the nuclear periphery supporting this idea.
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Affiliation(s)
| | | | | | - Einar Hallberg
- a Department of Neurochemistry , Stockholm University , Stockholm , Sweden
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22
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Chen M, Nowak DG, Narula N, Robinson B, Watrud K, Ambrico A, Herzka TM, Zeeman ME, Minderer M, Zheng W, Ebbesen SH, Plafker KS, Stahlhut C, Wang VMY, Wills L, Nasar A, Castillo-Martin M, Cordon-Cardo C, Wilkinson JE, Powers S, Sordella R, Altorki NK, Mittal V, Stiles BM, Plafker SM, Trotman LC. The nuclear transport receptor Importin-11 is a tumor suppressor that maintains PTEN protein. J Cell Biol 2017; 216:641-656. [PMID: 28193700 PMCID: PMC5350510 DOI: 10.1083/jcb.201604025] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Revised: 08/21/2016] [Accepted: 01/19/2017] [Indexed: 12/25/2022] Open
Abstract
Phosphatase and tensin homologue (PTEN) protein levels are critical for tumor suppression. However, the search for a recurrent cancer-associated gene alteration that causes PTEN degradation has remained futile. In this study, we show that Importin-11 (Ipo11) is a transport receptor for PTEN that is required to physically separate PTEN from elements of the PTEN degradation machinery. Mechanistically, we find that the E2 ubiquitin-conjugating enzyme and IPO11 cargo, UBE2E1, is a limiting factor for PTEN degradation. Using in vitro and in vivo gene-targeting methods, we show that Ipo11 loss results in degradation of Pten, lung adenocarcinoma, and neoplasia in mouse prostate with aberrantly high levels of Ube2e1 in the cytoplasm. These findings explain the correlation between loss of IPO11 and PTEN protein in human lung tumors. Furthermore, we find that IPO11 status predicts disease recurrence and progression to metastasis in patients choosing radical prostatectomy. Thus, our data introduce the IPO11 gene as a tumor-suppressor locus, which is of special importance in cancers that still retain at least one intact PTEN allele.
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Affiliation(s)
- Muhan Chen
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724
| | - Dawid G Nowak
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724
| | - Navneet Narula
- Department of Pathology, Neuberger Berman Lung Cancer Research Center, New York-Presbyterian Hospital, Weill Cornell Medical College, New York, NY 10065.,Department of Cell and Developmental Biology, Neuberger Berman Lung Cancer Research Center, New York-Presbyterian Hospital, Weill Cornell Medical College, New York, NY 10065
| | - Brian Robinson
- Department of Pathology, Neuberger Berman Lung Cancer Research Center, New York-Presbyterian Hospital, Weill Cornell Medical College, New York, NY 10065.,Department of Cell and Developmental Biology, Neuberger Berman Lung Cancer Research Center, New York-Presbyterian Hospital, Weill Cornell Medical College, New York, NY 10065
| | - Kaitlin Watrud
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724
| | | | - Tali M Herzka
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724
| | | | | | - Wu Zheng
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724
| | - Saya H Ebbesen
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724.,The Watson School of Biological Sciences, Cold Spring Harbor, NY 11724
| | - Kendra S Plafker
- Free Radical Biology and Aging Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104
| | | | | | - Lorna Wills
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724
| | - Abu Nasar
- Department of Cardiothoracic Surgery, Neuberger Berman Lung Cancer Research Center, New York-Presbyterian Hospital, Weill Cornell Medical College, New York, NY 10065
| | | | | | - John E Wilkinson
- Department of Pathology, University of Michigan, Ann Arbor, MI 48109
| | - Scott Powers
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724
| | | | - Nasser K Altorki
- Department of Cardiothoracic Surgery, Neuberger Berman Lung Cancer Research Center, New York-Presbyterian Hospital, Weill Cornell Medical College, New York, NY 10065
| | - Vivek Mittal
- Department of Cardiothoracic Surgery, Neuberger Berman Lung Cancer Research Center, New York-Presbyterian Hospital, Weill Cornell Medical College, New York, NY 10065
| | - Brendon M Stiles
- Department of Cardiothoracic Surgery, Neuberger Berman Lung Cancer Research Center, New York-Presbyterian Hospital, Weill Cornell Medical College, New York, NY 10065
| | - Scott M Plafker
- Free Radical Biology and Aging Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104
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23
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Beck M, Hurt E. The nuclear pore complex: understanding its function through structural insight. Nat Rev Mol Cell Biol 2016; 18:73-89. [PMID: 27999437 DOI: 10.1038/nrm.2016.147] [Citation(s) in RCA: 414] [Impact Index Per Article: 51.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Nuclear pore complexes (NPCs) fuse the inner and outer nuclear membranes to form channels across the nuclear envelope. They are large macromolecular assemblies with a complex composition and diverse functions. Apart from facilitating nucleocytoplasmic transport, NPCs are involved in chromatin organization, the regulation of gene expression and DNA repair. Understanding the molecular mechanisms underlying these functions has been hampered by a lack of structural knowledge about the NPC. The recent convergence of crystallographic and biochemical in vitro analysis of nucleoporins (NUPs), the components of the NPC, with cryo-electron microscopic imaging of the entire NPC in situ has provided first pseudo-atomic view of its central core and revealed that an unexpected network of short linear motifs is an important spatial organization principle. These breakthroughs have transformed the way we understand NPC structure, and they provide an important base for functional investigations, including the elucidation of the molecular mechanisms underlying clinically manifested mutations of the nucleocytoplasmic transport system.
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Affiliation(s)
- Martin Beck
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, Meyerhofstrasse 1, Heidelberg D-69117, Germany
| | - Ed Hurt
- Biochemistry Center of Heidelberg University, INF328, Heidelberg D-69120, Germany
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24
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Cheng Y, Yao J, Zhang Y, Li S, Kang Z. Characterization of a Ran gene from Puccinia striiformis f. sp. tritici involved in fungal growth and anti-cell death. Sci Rep 2016; 6:35248. [PMID: 27734916 PMCID: PMC5062253 DOI: 10.1038/srep35248] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 09/23/2016] [Indexed: 11/09/2022] Open
Abstract
Ran, an important family of small GTP-binding proteins, has been shown to regulate a variety of important cellular processes in many eukaryotes. However, little is known about Ran function in pathogenic fungi. In this study, we report the identification and functional analysis of a Ran gene (designated PsRan) from Puccinia striiformis f. sp. tritici (Pst), an important fungal pathogen affecting wheat production worldwide. The PsRan protein contains all conserved domains of Ran GTPases and shares more than 70% identity with Ran proteins from other organisms, indicating that Ran proteins are conserved in different organisms. PsRan shows a low level of intra-species polymorphism and is localized to the nucleus. qRT-PCR analysis showed that transcript level of PsRan was induced in planta during Pst infection. Silencing of PsRan did not alter Pst virulence phenotype but impeded fungal growth of Pst. In addition, heterologous overexpression of PsRan in plant failed to induce cell death but suppressed cell death triggered by a mouse BAX gene or a Pst Ras gene. Our results suggest that PsRan is involved in the regulation of fungal growth and anti-cell death, which provides significant insight into Ran function in pathogenic fungi.
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Affiliation(s)
- Yulin Cheng
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Life Sciences, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Juanni Yao
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Yanru Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Shumin Li
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Zhensheng Kang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling 712100, Shaanxi, China
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25
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Au S, Wu W, Zhou L, Theilmann DA, Panté N. A new mechanism for nuclear import by actin-based propulsion used by a baculovirus nucleocapsid. J Cell Sci 2016; 129:2905-11. [PMID: 27284005 DOI: 10.1242/jcs.191668] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 06/03/2016] [Indexed: 01/21/2023] Open
Abstract
The transport of macromolecules into the nucleus is mediated by soluble cellular receptors of the importin β superfamily and requires the Ran-GTPase cycle. Several studies have provided evidence that there are exceptions to this canonical nuclear import pathway. Here, we report a new unconventional nuclear import mechanism exploited by the baculovirus Autographa californica multiple nucleopolyhedrovirus (AcMNPV). We found that AcMNPV nucleocapsids entered the nucleus of digitonin-permeabilized cells in the absence of exogenous cytosol or under conditions that blocked the Ran-GTPase cycle. AcMNPV contains a protein that activates the Arp2/3 complex and induces actin polymerization at one end of the rod-shaped nucleocapsid. We show that inhibitors of Arp2/3 blocked nuclear import of nucleocapsids in semi-permeabilized cells. Nuclear import of nucleocapsids was also reconstituted in purified nuclei supplemented with G-actin and Arp2/3 under actin polymerization conditions. Thus, we propose that actin polymerization drives not only migration of baculovirus through the cytoplasm but also pushes the nucleocapsid through the nuclear pore complex to enter the cell nucleus. Our findings point to a very distinct role of actin-based motility during the baculovirus infection cycle.
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Affiliation(s)
- Shelly Au
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Wei Wu
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Lixin Zhou
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
| | - David A Theilmann
- Summerland Research and Development Centre, AAFC, Summerland, British Columbia, Canada
| | - Nelly Panté
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
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Lerner J, Bagattin A, Verdeguer F, Makinistoglu MP, Garbay S, Felix T, Heidet L, Pontoglio M. Human mutations affect the epigenetic/bookmarking function of HNF1B. Nucleic Acids Res 2016; 44:8097-111. [PMID: 27229139 PMCID: PMC5041451 DOI: 10.1093/nar/gkw467] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 05/13/2016] [Indexed: 12/19/2022] Open
Abstract
Bookmarking factors are transcriptional regulators involved in the mitotic transmission of epigenetic information via their ability to remain associated with mitotic chromatin. The mechanisms through which bookmarking factors bind to mitotic chromatin remain poorly understood. HNF1β is a bookmarking transcription factor that is frequently mutated in patients suffering from renal multicystic dysplasia and diabetes. Here, we show that HNF1β bookmarking activity is impaired by naturally occurring mutations found in patients. Interestingly, this defect in HNF1β mitotic chromatin association is rescued by an abrupt decrease in temperature. The rapid relocalization to mitotic chromatin is reversible and driven by a specific switch in DNA-binding ability of HNF1β mutants. Furthermore, we demonstrate that importin-β is involved in the maintenance of the mitotic retention of HNF1β, suggesting a functional link between the nuclear import system and the mitotic localization/translocation of bookmarking factors. Altogether, our studies have disclosed novel aspects on the mechanisms and the genetic programs that account for the mitotic association of HNF1β, a bookmarking factor that plays crucial roles in the epigenetic transmission of information through the cell cycle.
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Affiliation(s)
- Jonathan Lerner
- Department of Development, Reproduction and Cancer, Institut Cochin, INSERM U1016/CNRS UMR 8104/Université Paris-Descartes, Paris 75014, France
| | - Alessia Bagattin
- Department of Development, Reproduction and Cancer, Institut Cochin, INSERM U1016/CNRS UMR 8104/Université Paris-Descartes, Paris 75014, France
| | - Francisco Verdeguer
- Department of Development, Reproduction and Cancer, Institut Cochin, INSERM U1016/CNRS UMR 8104/Université Paris-Descartes, Paris 75014, France
| | - Munevver P Makinistoglu
- Department of Development, Reproduction and Cancer, Institut Cochin, INSERM U1016/CNRS UMR 8104/Université Paris-Descartes, Paris 75014, France
| | - Serge Garbay
- Department of Development, Reproduction and Cancer, Institut Cochin, INSERM U1016/CNRS UMR 8104/Université Paris-Descartes, Paris 75014, France
| | - Tristan Felix
- Department of Development, Reproduction and Cancer, Institut Cochin, INSERM U1016/CNRS UMR 8104/Université Paris-Descartes, Paris 75014, France
| | - Laurence Heidet
- Department of Pediatric Nephrology, Assistance Publique des Hôpitaux de Paris, Centre de référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte (MARHEA), Hospital Necker-Enfants Malades, Paris 75015, France
| | - Marco Pontoglio
- Department of Development, Reproduction and Cancer, Institut Cochin, INSERM U1016/CNRS UMR 8104/Université Paris-Descartes, Paris 75014, France
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27
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Ritterhoff T, Das H, Hofhaus G, Schröder RR, Flotho A, Melchior F. The RanBP2/RanGAP1*SUMO1/Ubc9 SUMO E3 ligase is a disassembly machine for Crm1-dependent nuclear export complexes. Nat Commun 2016; 7:11482. [PMID: 27160050 PMCID: PMC4866044 DOI: 10.1038/ncomms11482] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2015] [Accepted: 03/31/2016] [Indexed: 02/07/2023] Open
Abstract
Continuous cycles of nucleocytoplasmic transport require disassembly of transport receptor/Ran-GTP complexes in the cytoplasm. A basic disassembly mechanism in all eukaryotes depends on soluble RanGAP and RanBP1. In vertebrates, a significant fraction of RanGAP1 stably interacts with the nucleoporin RanBP2 at a binding site that is flanked by FG-repeats and Ran-binding domains, and overlaps with RanBP2's SUMO E3 ligase region. Here, we show that the RanBP2/RanGAP1*SUMO1/Ubc9 complex functions as an autonomous disassembly machine with a preference for the export receptor Crm1. We describe three in vitro reconstituted disassembly intermediates, which show binding of a Crm1 export complex via two FG-repeat patches, cargo-release by RanBP2's Ran-binding domains and retention of free Crm1 at RanBP2 after Ran-GTP hydrolysis. Intriguingly, all intermediates are compatible with SUMO E3 ligase activity, suggesting that the RanBP2/RanGAP1*SUMO1/Ubc9 complex may link Crm1- and SUMO-dependent functions.
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Affiliation(s)
- Tobias Ritterhoff
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, Heidelberg 69120, Germany
- Department of Biochemistry, University of Washington, Seattle, Washington 98195, USA
| | - Hrishikesh Das
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, Heidelberg 69120, Germany
- Cryo Electron Microscopy, CellNetworks, BioQuant, Universitätsklinikum Heidelberg, Heidelberg 69120, Germany
| | - Götz Hofhaus
- Cryo Electron Microscopy, CellNetworks, BioQuant, Universitätsklinikum Heidelberg, Heidelberg 69120, Germany
| | - Rasmus R. Schröder
- Cryo Electron Microscopy, CellNetworks, BioQuant, Universitätsklinikum Heidelberg, Heidelberg 69120, Germany
| | - Annette Flotho
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, Heidelberg 69120, Germany
| | - Frauke Melchior
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, Heidelberg 69120, Germany
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28
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Wang YP, Du WJ, Huang LP, Wei YW, Wu HL, Feng L, Liu CM. The Pseudorabies Virus DNA Polymerase Accessory Subunit UL42 Directs Nuclear Transport of the Holoenzyme. Front Microbiol 2016; 7:124. [PMID: 26913023 PMCID: PMC4753316 DOI: 10.3389/fmicb.2016.00124] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 01/25/2016] [Indexed: 01/13/2023] Open
Abstract
Pseudorabies virus (PRV) DNA replication occurs in the nuclei of infected cells and requires the viral DNA polymerase. The PRV DNA polymerase comprises a catalytic subunit, UL30, and an accessory subunit, UL42, that confers processivity to the enzyme. Its nuclear localization is a prerequisite for its enzymatic function in the initiation of viral DNA replication. However, the mechanisms by which the PRV DNA polymerase holoenzyme enters the nucleus have not been determined. In this study, we characterized the nuclear import pathways of the PRV DNA polymerase catalytic and accessory subunits. Immunofluorescence analysis showed that UL42 localizes independently in the nucleus, whereas UL30 alone predominantly localizes in the cytoplasm. Intriguingly, the localization of UL30 was completely shifted to the nucleus when it was coexpressed with UL42, demonstrating that nuclear transport of UL30 occurs in an UL42-dependent manner. Deletion analysis and site-directed mutagenesis of the two proteins showed that UL42 contains a functional and transferable bipartite nuclear localization signal (NLS) at amino acids 354–370 and that K354, R355, and K367 are important for the NLS function, whereas UL30 has no NLS. Coimmunoprecipitation assays verified that UL42 interacts with importins α3 and α4 through its NLS. In vitro nuclear import assays demonstrated that nuclear accumulation of UL42 is a temperature- and energy-dependent process and requires both importins α and β, confirming that UL42 utilizes the importin α/β-mediated pathway for nuclear entry. In an UL42 NLS-null mutant, the UL42/UL30 heterodimer was completely confined to the cytoplasm when UL42 was coexpressed with UL30, indicating that UL30 utilizes the NLS function of UL42 for its translocation into the nucleus. Collectively, these findings suggest that UL42 contains an importin α/β-mediated bipartite NLS that transports the viral DNA polymerase holoenzyme into the nucleus in an in vitro expression system.
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Affiliation(s)
- Yi-Ping Wang
- Division of Swine Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences Harbin, China
| | - Wen-Juan Du
- Division of Swine Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences Harbin, China
| | - Li-Ping Huang
- Division of Swine Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences Harbin, China
| | - Yan-Wu Wei
- Division of Swine Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences Harbin, China
| | - Hong-Li Wu
- Division of Swine Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences Harbin, China
| | - Li Feng
- Division of Swine Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences Harbin, China
| | - Chang-Ming Liu
- Division of Swine Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences Harbin, China
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29
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Fahrenkrog B. Histone modifications as regulators of life and death in Saccharomyces cerevisiae. MICROBIAL CELL 2015; 3:1-13. [PMID: 28357312 PMCID: PMC5354586 DOI: 10.15698/mic2016.01.472] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Apoptosis or programmed cell death is an integrated, genetically controlled
suicide program that not only regulates tissue homeostasis of multicellular
organisms, but also the fate of damaged and aged cells of lower eukaryotes, such
as the yeast Saccharomyces cerevisiae. Recent years have
revealed key apoptosis regulatory proteins in yeast that play similar roles in
mammalian cells. Apoptosis is a process largely defined by characteristic
structural rearrangements in the dying cell that include chromatin condensation
and DNA fragmentation. The mechanism by which chromosomes restructure during
apoptosis is still poorly understood, but it is becoming increasingly clear that
altered epigenetic histone modifications are fundamental parameters that
influence the chromatin state and the nuclear rearrangements within apoptotic
cells. The present review will highlight recent work on the epigenetic
regulation of programmed cell death in budding yeast.
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Affiliation(s)
- Birthe Fahrenkrog
- Institute of Molecular Biology and Medicine, Université Libre de Bruxelles, Rue Profs. Jeener et Brachet 12; 6041 Charleroi, Belgium
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30
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Transport Selectivity of Nuclear Pores, Phase Separation, and Membraneless Organelles. Trends Biochem Sci 2015; 41:46-61. [PMID: 26705895 DOI: 10.1016/j.tibs.2015.11.001] [Citation(s) in RCA: 289] [Impact Index Per Article: 32.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 10/30/2015] [Accepted: 11/03/2015] [Indexed: 12/21/2022]
Abstract
Nuclear pore complexes (NPCs) provide a selective passageway for receptor-mediated active transport between nucleus and cytoplasm, while maintaining the distinct molecular compositions of both compartments at large. In this review we discuss how NPCs gain a remarkable sorting selectivity from non-globular FG domains and their phase separation into dense polymer meshworks. The resulting sieve-like FG hydrogels are effective barriers to normal macromolecules but are at the same time highly permeable to shuttling nuclear transport receptors, which bind to FG motifs as well as to their designated cargoes. Phase separation driven by disordered protein domains was recently also recognized as being pivotal to the formation of membraneless organelles, making it an important emerging principle in cell biology.
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31
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SUBRAMANIAN ABHISHEK, SARKAR RAMRUP. DYNAMICS OF GLI REGULATION AND A STRATEGY TO CONTROL CANCEROUS SITUATION: HEDGEHOG SIGNALING PATHWAY REVISITED. J BIOL SYST 2015. [DOI: 10.1142/s0218339015500333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The hedgehog signaling cascade generates highly diverse, fine-tuned responses in response to the external stimulus by the sonic hedgehog (SHH) protein. This is required for the flawless functioning of the cell, its development, survival and proliferation; maintained through production of Glioma protein (GLI) and transcriptional activation of its target genes. Any change in the behavior of GLI response by ectopic expression of SHH or mutations in the core pathway components may cause serious consequences in the cell fate through rapid, uncontrolled and elevated production of GLI. Here, we present a simple but extensive computational model that considers the detailed reaction mechanisms involved in the hedgehog signal transduction and provides a detailed insight into regulation of GLI. For the first time, by explicit involvement of suppressor of fused (SUFU) and Hedgehog interacting protein (HHIP) reaction kinetics in the model, we try to demonstrate the vital importance of HHIP and SUFU in maintaining the graded response of GLI in response to SHH. By performing parameter variations, we capture the conversion of a graded response of GLI to an ultrasensitive switch under SUFU-deficient conditions that might predispose abnormal embryonic development and the irreversible switching response of GLI that corresponds to signal-independent pathway activation observed in cancers.
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Affiliation(s)
- ABHISHEK SUBRAMANIAN
- Chemical Engineering and Process Development CSIR-National Chemical Laboratory Pune-411008, Maharashtra, India
- Academy of Scientific & Innovative Research (AcSIR) CSIR-NCL Campus, Pune, India
| | - RAM RUP SARKAR
- Chemical Engineering and Process Development CSIR-National Chemical Laboratory Pune-411008, Maharashtra, India
- Academy of Scientific & Innovative Research (AcSIR) CSIR-NCL Campus, Pune, India
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32
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Ran Involved in the Development and Reproduction Is a Potential Target for RNA-Interference-Based Pest Management in Nilaparvata lugens. PLoS One 2015; 10:e0142142. [PMID: 26554926 PMCID: PMC4640576 DOI: 10.1371/journal.pone.0142142] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 10/19/2015] [Indexed: 11/27/2022] Open
Abstract
Ran (RanGTPase) in insects participates in the 20-hydroxyecdysone signal transduction pathway in which downstream genes, FTZ-F1, Krüppel-homolog 1 (Kr-h1) and vitellogenin, are involved. A putative Ran gene (NlRan) was cloned from Nilaparvata lugens, a destructive phloem-feeding pest of rice. NlRan has the typical Ran primary structure features that are conserved in insects. NlRan showed higher mRNA abundance immediately after molting and peaked in newly emerged female adults. Among the examined tissues ovary had the highest transcript level, followed by fat body, midgut and integument, and legs. Three days after dsNlRan injection the NlRan mRNA abundance in the third-, fourth-, and fifth-instar nymphs was decreased by 94.3%, 98.4% and 97.0%, respectively. NlFTZ-F1 expression levels in treated third- and fourth-instar nymphs were reduced by 89.3% and 23.8%, respectively. In contrast, NlKr-h1 mRNA levels were up-regulated by 67.5 and 1.5 folds, respectively. NlRan knockdown significantly decreased the body weights, delayed development, and killed >85% of the nymphs at day seven. Two apparent phenotypic defects were observed: (1) Extended body form, and failed to molt; (2) The cuticle at the notum was split open but cannot completely shed off. The newly emerged female adults from dsNlRan injected fifth-instar nymphs showed lower levels of NlRan and vitellogenin, lower weight gain and honeydew excretion comparing with the blank control, and no offspring. Those results suggest that NlRan encodes a functional protein that was involved in development and reproduction. The study established proof of concept that NlRan could serve as a target for dsRNA-based pesticides for N. lugens control.
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33
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Abstract
In 1996, Matunis et al. were one of several groups to identify a novel, ubiquitin-like protein modification.
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34
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Complex Commingling: Nucleoporins and the Spindle Assembly Checkpoint. Cells 2015; 4:706-25. [PMID: 26540075 PMCID: PMC4695854 DOI: 10.3390/cells4040706] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 10/12/2015] [Accepted: 10/28/2015] [Indexed: 12/14/2022] Open
Abstract
The segregation of the chromosomes during mitosis is an important process, in which the replicated DNA content is properly allocated into two daughter cells. To ensure their genomic integrity, cells present an essential surveillance mechanism known as the spindle assembly checkpoint (SAC), which monitors the bipolar attachment of the mitotic spindle to chromosomes to prevent errors that would result in chromosome mis-segregation and aneuploidy. Multiple components of the nuclear pore complex (NPC), a gigantic protein complex that forms a channel through the nuclear envelope to allow nucleocytoplasmic exchange of macromolecules, were shown to be critical for faithful cell division and implicated in the regulation of different steps of the mitotic process, including kinetochore and spindle assembly as well as the SAC. In this review, we will describe current knowledge about the interconnection between the NPC and the SAC in an evolutional perspective, which primarily relies on the two mitotic checkpoint regulators, Mad1 and Mad2. We will further discuss the role of NPC constituents, the nucleoporins, in kinetochore and spindle assembly and the formation of the mitotic checkpoint complex during mitosis and interphase.
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35
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Christie M, Chang CW, Róna G, Smith KM, Stewart AG, Takeda AAS, Fontes MRM, Stewart M, Vértessy BG, Forwood JK, Kobe B. Structural Biology and Regulation of Protein Import into the Nucleus. J Mol Biol 2015; 428:2060-90. [PMID: 26523678 DOI: 10.1016/j.jmb.2015.10.023] [Citation(s) in RCA: 181] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 10/16/2015] [Accepted: 10/24/2015] [Indexed: 11/28/2022]
Abstract
Proteins are translated in the cytoplasm, but many need to access the nucleus to perform their functions. Understanding how these nuclear proteins are transported through the nuclear envelope and how the import processes are regulated is therefore an important aspect of understanding cell function. Structural biology has played a key role in understanding the molecular events during the transport processes and their regulation, including the recognition of nuclear targeting signals by the corresponding receptors. Here, we review the structural basis of the principal nuclear import pathways and the molecular basis of their regulation. The pathways involve transport factors that are members of the β-karyopherin family, which can bind cargo directly (e.g., importin-β, transportin-1, transportin-3, importin-13) or through adaptor proteins (e.g., importin-α, snurportin-1, symportin-1), as well as unrelated transport factors such as Hikeshi, involved in the transport of heat-shock proteins, and NTF2, involved in the transport of RanGDP. Solenoid proteins feature prominently in these pathways. Nuclear transport factors recognize nuclear targeting signals on the cargo proteins, including the classical nuclear localization signals, recognized by the adaptor importin-α, and the PY nuclear localization signals, recognized by transportin-1. Post-translational modifications, particularly phosphorylation, constitute key regulatory mechanisms operating in these pathways.
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Affiliation(s)
- Mary Christie
- The Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, NSW 2010, Australia; St Vincent's Clinical School, University of New South Wales Faculty of Medicine, Darlinghurst, NSW 2010, Australia
| | - Chiung-Wen Chang
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, QLD 4072, Australia; Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Gergely Róna
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest H-1117, Hungary; Department of Applied Biotechnology and Food Sciences, Budapest University of Technology and Economics, Budapest H-1111, Hungary
| | - Kate M Smith
- School of Biomedical Sciences, Charles Sturt University, Wagga Wagga, NSW 2650, Australia
| | - Alastair G Stewart
- School of Molecular Bioscience, The University of Sydney, Sydney, NSW 2006, Australia
| | - Agnes A S Takeda
- Department of Physics and Biophysics, Institute of Biosciences, Universidade Estadual Paulista, Botucatu, São Paulo 18618-000, Brazil
| | - Marcos R M Fontes
- Department of Physics and Biophysics, Institute of Biosciences, Universidade Estadual Paulista, Botucatu, São Paulo 18618-000, Brazil
| | - Murray Stewart
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, QLD 4072, Australia; MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, United Kingdom
| | - Beáta G Vértessy
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest H-1117, Hungary; Department of Applied Biotechnology and Food Sciences, Budapest University of Technology and Economics, Budapest H-1111, Hungary
| | - Jade K Forwood
- School of Biomedical Sciences, Charles Sturt University, Wagga Wagga, NSW 2650, Australia
| | - Bostjan Kobe
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, QLD 4072, Australia.
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36
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Spatiotemporal Regulation of Nuclear Transport Machinery and Microtubule Organization. Cells 2015; 4:406-26. [PMID: 26308057 PMCID: PMC4588043 DOI: 10.3390/cells4030406] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 07/30/2015] [Accepted: 08/19/2015] [Indexed: 12/23/2022] Open
Abstract
Spindle microtubules capture and segregate chromosomes and, therefore, their assembly is an essential event in mitosis. To carry out their mission, many key players for microtubule formation need to be strictly orchestrated. Particularly, proteins that assemble the spindle need to be translocated at appropriate sites during mitosis. A small GTPase (hydrolase enzyme of guanosine triphosphate), Ran, controls this translocation. Ran plays many roles in many cellular events: nucleocytoplasmic shuttling through the nuclear envelope, assembly of the mitotic spindle, and reorganization of the nuclear envelope at the mitotic exit. Although these events are seemingly distinct, recent studies demonstrate that the mechanisms underlying these phenomena are substantially the same as explained by molecular interplay of the master regulator Ran, the transport factor importin, and its cargo proteins. Our review focuses on how the transport machinery regulates mitotic progression of cells. We summarize translocation mechanisms governed by Ran and its regulatory proteins, and particularly focus on Ran-GTP targets in fission yeast that promote spindle formation. We also discuss the coordination of the spatial and temporal regulation of proteins from the viewpoint of transport machinery. We propose that the transport machinery is an essential key that couples the spatial and temporal events in cells.
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37
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Sakin V, Richter SM, Hsiao HH, Urlaub H, Melchior F. Sumoylation of the GTPase Ran by the RanBP2 SUMO E3 Ligase Complex. J Biol Chem 2015; 290:23589-602. [PMID: 26251516 DOI: 10.1074/jbc.m115.660118] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Indexed: 12/20/2022] Open
Abstract
The SUMO E3 ligase complex RanBP2/RanGAP1*SUMO1/Ubc9 localizes at cytoplasmic nuclear pore complex (NPC) filaments and is a docking site in nucleocytoplasmic transport. RanBP2 has four Ran binding domains (RBDs), two of which flank RanBP2's E3 ligase region. We thus wondered whether the small GTPase Ran is a target for RanBP2-dependent sumoylation. Indeed, Ran is sumoylated both by a reconstituted and the endogenous RanBP2 complex in semi-permeabilized cells. Generic inhibition of SUMO isopeptidases or depletion of the SUMO isopeptidase SENP1 enhances sumoylation of Ran in semi-permeabilized cells. As Ran is typically associated with transport receptors, we tested the influence of Crm1, Imp β, Transportin, and NTF2 on Ran sumoylation. Surprisingly, all inhibited Ran sumoylation. Mapping Ran sumoylation sites revealed that transport receptors may simply block access of the E2-conjugating enzyme Ubc9, however the acceptor lysines are perfectly accessible in Ran/NTF2 complexes. Isothermal titration calorimetry revealed that NTF2 prevents sumoylation by reducing RanGDP's affinity to RanBP2's RBDs to undetectable levels. Taken together, our findings indicate that RanGDP and not RanGTP is the physiological target for the RanBP2 SUMO E3 ligase complex. Recognition requires interaction of Ran with RanBP2's RBDs, which is prevented by the transport factor NTF2.
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Affiliation(s)
- Volkan Sakin
- From the Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), DKFZ, ZMBH Alliance, Heidelberg, Germany
| | - Sebastian M Richter
- From the Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), DKFZ, ZMBH Alliance, Heidelberg, Germany
| | - He-Hsuan Hsiao
- Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany, and
| | - Henning Urlaub
- Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany, and Department of Clinical Chemistry, University Medical Center, 37075 Göttingen, Germany
| | - Frauke Melchior
- From the Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), DKFZ, ZMBH Alliance, Heidelberg, Germany,
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38
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Melendez DP, Razonable RR. Letermovir and inhibitors of the terminase complex: a promising new class of investigational antiviral drugs against human cytomegalovirus. Infect Drug Resist 2015; 8:269-77. [PMID: 26345608 PMCID: PMC4531042 DOI: 10.2147/idr.s79131] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Infection with cytomegalovirus is prevalent in immunosuppressed patients. In solid organ transplant and hematopoietic stem cell transplant recipients, cytomegalovirus infection is associated with high morbidity and preventable mortality. Prevention and treatment of cytomegalovirus with currently approved antiviral drugs is often associated with side effects that sometimes preclude their use. Moreover, cytomegalovirus has developed mutations that confer resistance to standard antiviral drugs. During the last decade, there have been calls to develop novel antiviral drugs that could provide better options for prevention and treatment of cytomegalovirus. Letermovir (AIC246) is a highly specific antiviral drug that is currently undergoing clinical development for the management of cytomegalovirus infection. It acts by inhibiting the viral terminase complex. Letermovir is highly potent in vitro and in vivo against cytomegalovirus. Because of a distinct mechanism of action, it does not exhibit cross-resistance with other antiviral drugs. It is predicted to be active against strains that are resistant to ganciclovir, foscarnet, and cidofovir. To date, early-phase clinical trials suggest a very low incidence of adverse effects. Herein, we present a comprehensive review on letermovir, from its postulated novel mechanism of action to the results of most recent clinical studies.
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Affiliation(s)
- Dante P Melendez
- Division of Infectious Diseases, Mayo Clinic, Rochester, MN, USA ; William J von Liebig Center for Transplantation and Clinical Regeneration, Mayo Clinic, Rochester, MN, USA
| | - Raymund R Razonable
- Division of Infectious Diseases, Mayo Clinic, Rochester, MN, USA ; William J von Liebig Center for Transplantation and Clinical Regeneration, Mayo Clinic, Rochester, MN, USA
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39
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Proteomic analyses reveal that loss of TDP-43 affects RNA processing and intracellular transport. Neuroscience 2015; 293:157-70. [PMID: 25743254 DOI: 10.1016/j.neuroscience.2015.02.046] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 02/23/2015] [Accepted: 02/24/2015] [Indexed: 12/12/2022]
Abstract
Transactive response DNA-binding protein 43 (TDP-43) is a predominantly nuclear, ubiquitously expressed RNA and DNA-binding protein. It recognizes and binds to UG repeats and is involved in pre-mRNA splicing, mRNA stability and microRNA metabolism. TDP-43 is essential in early embryonic development but accumulates in cytoplasmic aggregates in amyotrophic lateral sclerosis (ALS) and tau-negative frontotemporal lobar degeneration (FTLD). It is not known yet whether cytoplasmic aggregates of TDP-43 are toxic or protective but they are often associated with a loss of TDP-43 from the nucleus and neurodegeneration may be caused by a loss of normal TDP-43 function or a gain of toxic function. Here we present a proteomic study to analyze the effect of loss of TDP-43 on the proteome. MS data are available via ProteomeXchange with identifier PXD001668. Our results indicate that TDP-43 is an important regulator of RNA metabolism and intracellular transport. We show that Ran-binding protein 1 (RanBP1), DNA methyltransferase 3 alpha (Dnmt3a) and chromogranin B (CgB) are downregulated upon TDP-43 knockdown. Subsequently, transportin 1 level is increased as a result of RanBP1 depletion. Improper regulation of these proteins and the subsequent disruption of cellular processes may play a role in the pathogenesis of the TDP-43 proteinopathies ALS and FTLD.
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40
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Gurling M, Garriga G. The two faces of TOE-2. WORM 2015; 4:e979697. [PMID: 26430558 DOI: 10.4161/21624054.2014.979697] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Revised: 10/07/2014] [Accepted: 10/20/2014] [Indexed: 11/19/2022]
Abstract
The C. elegans Q lineage provides a unique context for studying how cells divide asymmetrically to generate cells fated to die. The Q cell divides to form the Q.a and Q.p neuroblasts, each of which divides to produce neurons and a cell that dies by apoptosis; however, these neuroblasts employ different mechanisms to divide asymmetrically.(1) We discovered 2 distinct roles for TOE-2, a protein previously shown to be a target of the C. elegans ERK ortholog MPK-1, in promoting apoptosis in each of these neuroblast divisions. In this commentary, we discuss possible molecular mechanisms by which TOE-2 promotes apoptosis. Specifically, we will discuss potential roles for TOE-2 interacting proteins, a possible nuclear function for TOE-2, and a potential link to the Wnt pathway.
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Affiliation(s)
- Mark Gurling
- Molecular and Cell Biology; University of California ; Berkeley, CA USA ; Present address: Department of Biochemistry; University of Utah ; Salt Lake City, UT USA
| | - Gian Garriga
- Molecular and Cell Biology; University of California ; Berkeley, CA USA
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41
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Cautain B, Hill R, de Pedro N, Link W. Components and regulation of nuclear transport processes. FEBS J 2014; 282:445-62. [PMID: 25429850 PMCID: PMC7163960 DOI: 10.1111/febs.13163] [Citation(s) in RCA: 177] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Revised: 11/11/2014] [Accepted: 11/12/2014] [Indexed: 12/27/2022]
Abstract
The spatial separation of DNA replication and gene transcription in the nucleus and protein translation in the cytoplasm is a uniform principle of eukaryotic cells. This compartmentalization imposes a requirement for a transport network of macromolecules to shuttle these components in and out of the nucleus. This nucleo‐cytoplasmic transport of macromolecules is critical for both cell physiology and pathology. Consequently, investigating its regulation and disease‐associated alterations can reveal novel therapeutic approaches to fight human diseases, such as cancer or viral infection. The characterization of the nuclear pore complex, the identification of transport signals and transport receptors, as well as the characterization of the Ran system (providing the energy source for efficient cargo transport) has greatly facilitated our understanding of the components, mechanisms and regulation of the nucleo‐cytoplasmic transport of proteins in our cells. Here we review this knowledge with a specific emphasis on the selection of disease‐relevant molecular targets for potential therapeutic intervention.
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Affiliation(s)
- Bastien Cautain
- Fundacion MEDINA Parque tecnológico ciencias de la salud, Granada, Spain
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42
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Cox AD, Der CJ. Ras history: The saga continues. Small GTPases 2014; 1:2-27. [PMID: 21686117 DOI: 10.4161/sgtp.1.1.12178] [Citation(s) in RCA: 506] [Impact Index Per Article: 50.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2010] [Revised: 05/17/2010] [Accepted: 05/24/2010] [Indexed: 12/24/2022] Open
Abstract
Although the roots of Ras sprouted from the rich history of retrovirus research, it was the discovery of mutationally activated RAS genes in human cancer in 1982 that stimulated an intensive research effort to understand Ras protein structure, biochemistry and biology. While the ultimate goal has been developing anti-Ras drugs for cancer treatment, discoveries from Ras have laid the foundation for three broad areas of science. First, they focused studies on the origins of cancer to the molecular level, with the subsequent discovery of genes mutated in cancer that now number in the thousands. Second, elucidation of the biochemical mechanisms by which Ras facilitates signal transduction established many of our fundamental concepts of how a normal cell orchestrates responses to extracellular cues. Third, Ras proteins are also founding members of a large superfamily of small GTPases that regulate all key cellular processes and established the versatile role of small GTP-binding proteins in biology. We highlight some of the key findings of the last 28 years.
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Affiliation(s)
- Adrienne D Cox
- Department of Radiation Oncology; Lineberger Comprehensive Cancer Center; University of North Carolina at Chapel Hill; Chapel Hill, NC USA
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43
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Lu M, Zak J, Chen S, Sanchez-Pulido L, Severson DT, Endicott J, Ponting CP, Schofield CJ, Lu X. A code for RanGDP binding in ankyrin repeats defines a nuclear import pathway. Cell 2014; 157:1130-45. [PMID: 24855949 DOI: 10.1016/j.cell.2014.05.006] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Revised: 01/22/2014] [Accepted: 03/13/2014] [Indexed: 01/23/2023]
Abstract
Regulation of nuclear import is fundamental to eukaryotic biology. The majority of nuclear import pathways are mediated by importin-cargo interactions. Yet not all nuclear proteins interact with importins, necessitating the identification of a general importin-independent nuclear import pathway. Here, we identify a code that determines importin-independent nuclear import of ankyrin repeats (ARs), a structural motif found in over 250 human proteins with diverse functions. AR-containing proteins (ARPs) with a hydrophobic residue at the 13th position of two consecutive ARs bind RanGDP efficiently, and consequently enter the nucleus. This code, experimentally tested in 17 ARPs, predicts the nuclear-cytoplasmic localization of over 150 annotated human ARPs with high accuracy and is acquired by the most common familial melanoma-associated CDKN2A mutation, leading to nuclear accumulation of mutant p16ink4a. The RaDAR (RanGDP/AR) pathway represents a general importin-independent nuclear import pathway and is frequently used by AR-containing transcriptional regulators, especially those regulating NF-κB/p53.
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Affiliation(s)
- Min Lu
- Ludwig Institute for Cancer Research, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, OX3 7DQ, UK
| | - Jaroslav Zak
- Ludwig Institute for Cancer Research, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, OX3 7DQ, UK
| | - Shuo Chen
- Ludwig Institute for Cancer Research, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, OX3 7DQ, UK
| | - Luis Sanchez-Pulido
- MRC Functional Genomics Unit, Department of Physiology Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK
| | - David T Severson
- Ludwig Institute for Cancer Research, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, OX3 7DQ, UK
| | - Jane Endicott
- Northern Institute for Cancer Research, University of Newcastle, Newcastle, NE2 4HH, UK
| | - Chris P Ponting
- MRC Functional Genomics Unit, Department of Physiology Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK
| | - Christopher J Schofield
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, OX1 3TA, UK
| | - Xin Lu
- Ludwig Institute for Cancer Research, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, OX3 7DQ, UK.
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Bernis C, Swift-Taylor B, Nord M, Carmona S, Chook YM, Forbes DJ. Transportin acts to regulate mitotic assembly events by target binding rather than Ran sequestration. Mol Biol Cell 2014; 25:992-1009. [PMID: 24478460 PMCID: PMC3967982 DOI: 10.1091/mbc.e13-08-0506] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Transportin-specific molecular tools are used to show that the mitotic cell contains importin β and transportin “global positioning system” pathways that are mechanistically parallel. Transportin works to control where the spindle, nuclear membrane, and nuclear pores are formed by directly affecting assembly factor function. The nuclear import receptors importin β and transportin play a different role in mitosis: both act phenotypically as spatial regulators to ensure that mitotic spindle, nuclear membrane, and nuclear pore assembly occur exclusively around chromatin. Importin β is known to act by repressing assembly factors in regions distant from chromatin, whereas RanGTP produced on chromatin frees factors from importin β for localized assembly. The mechanism of transportin regulation was unknown. Diametrically opposed models for transportin action are as follows: 1) indirect action by RanGTP sequestration, thus down-regulating release of assembly factors from importin β, and 2) direct action by transportin binding and inhibiting assembly factors. Experiments in Xenopus assembly extracts with M9M, a superaffinity nuclear localization sequence that displaces cargoes bound by transportin, or TLB, a mutant transportin that can bind cargo and RanGTP simultaneously, support direct inhibition. Consistently, simple addition of M9M to mitotic cytosol induces microtubule aster assembly. ELYS and the nucleoporin 107–160 complex, components of mitotic kinetochores and nuclear pores, are blocked from binding to kinetochores in vitro by transportin, a block reversible by M9M. In vivo, 30% of M9M-transfected cells have spindle/cytokinesis defects. We conclude that the cell contains importin β and transportin “global positioning system”or “GPS” pathways that are mechanistically parallel.
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Affiliation(s)
- Cyril Bernis
- Section of Cell and Developmental Biology, Division of Biological Sciences 0347, University of California-San Diego, La Jolla, CA 92093-0347 Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9041
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45
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Recombinant adeno-associated virus utilizes host cell nuclear import machinery to enter the nucleus. J Virol 2014; 88:4132-44. [PMID: 24478436 DOI: 10.1128/jvi.02660-13] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Recombinant adeno-associated viral (rAAV) vectors have garnered much promise in gene therapy applications. However, widespread clinical use has been limited by transduction efficiency. Previous studies suggested that the majority of rAAV accumulates in the perinuclear region of cells, presumably unable to traffic into the nucleus. rAAV nuclear translocation remains ill-defined; therefore, we performed microscopy, genetic, and biochemical analyses in vitro in order to understand this mechanism. Lectin blockade of the nuclear pore complex (NPC) resulted in inhibition of nuclear rAAV2. Visualization of fluorescently labeled particles revealed that rAAV2 localized to importin-β-dense regions of cells in late trafficking steps. Additionally, small interfering RNA (siRNA) knockdown of importin-β partially inhibited rAAV2 nuclear translocation and inhibited transduction by 50 to 70%. Furthermore, coimmunopreciptation (co-IP) analysis revealed that capsid proteins from rAAV2 could interact with importin-β and that this interaction was sensitive to the small GTPase Ran. More importantly, mutations to key basic regions in the rAAV2 capsid severely inhibited interactions with importin-β. We tested several other serotypes and found that the extent of importin-β interaction varied, suggesting that different serotypes may utilize alternative import proteins for nuclear translocation. Co-IP and siRNA analyses were used to investigate the role of other karyopherins, and the results suggested that rAAV2 may utilize multiple import proteins for nuclear entry. Taken together, our results suggest that rAAV2 interacts with importin-β alone or in complex with other karyopherins and enters the nucleus via the NPC. These results may lend insight into the design of novel AAV vectors that have an enhanced nuclear entry capability and transduction potential. IMPORTANCE Use of recombinant adeno-associated viral (rAAV) vectors for gene therapy applications is limited by relatively low transduction efficiency, in part due to cellular barriers that hinder successful subcellular trafficking to the nucleus, where uncoating and subsequent gene expression occur. Nuclear translocation of rAAV has been regarded as a limiting step for successful transduction but it remains ill-defined. We explored potential nuclear entry mechanisms for rAAV2 and found that rAAV2 can utilize the classical nuclear import pathway, involving the nuclear pore complex, the small GTPase Ran, and cellular karyopherins. These results could lend insight into the rational design of novel rAAV vectors that can more efficiently translocate to the nucleus, which may lead to more efficient transduction.
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46
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Ran GTPase in nuclear envelope formation and cancer metastasis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 773:323-51. [PMID: 24563355 DOI: 10.1007/978-1-4899-8032-8_15] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Ran is a small ras-related GTPase that controls the nucleocytoplasmic exchange of macromolecules across the nuclear envelope. It binds to chromatin early during nuclear formation and has important roles during the eukaryotic cell cycle, where it regulates mitotic spindle assembly, nuclear envelope formation and cell cycle checkpoint control. Like other GTPases, Ran relies on the cycling between GTP-bound and GDP-bound conformations to interact with effector proteins and regulate these processes. In nucleocytoplasmic transport, Ran shuttles across the nuclear envelope through nuclear pores. It is concentrated in the nucleus by an active import mechanism where it generates a high concentration of RanGTP by nucleotide exchange. It controls the assembly and disassembly of a range of complexes that are formed between Ran-binding proteins and cellular cargo to maintain rapid nuclear transport. Ran also has been identified as an essential protein in nuclear envelope formation in eukaryotes. This mechanism is dependent on importin-β, which regulates the assembly of further complexes important in this process, such as Nup107-Nup160. A strong body of evidence is emerging implicating Ran as a key protein in the metastatic progression of cancer. Ran is overexpressed in a range of tumors, such as breast and renal, and these perturbed levels are associated with local invasion, metastasis and reduced patient survival. Furthermore, tumors with oncogenic KRAS or PIK3CA mutations are addicted to Ran expression, which yields exciting future therapeutic opportunities.
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47
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Floch AG, Palancade B, Doye V. Fifty years of nuclear pores and nucleocytoplasmic transport studies: multiple tools revealing complex rules. Methods Cell Biol 2014; 122:1-40. [PMID: 24857723 DOI: 10.1016/b978-0-12-417160-2.00001-1] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Nuclear pore complexes (NPCs) are multiprotein assemblies embedded within the nuclear envelope and involved in the control of the bidirectional transport of proteins and ribonucleoparticles between the nucleus and the cytoplasm. Since their discovery more than 50 years ago, NPCs and nucleocytoplasmic transport have been the focus of intense research. Here, we review how the use of a multiplicity of structural, biochemical, genetic, and cell biology approaches have permitted the deciphering of the main features of this macromolecular complex, its mode of assembly as well as the rules governing nucleocytoplasmic exchanges. We first present the current knowledge of the ultrastructure of NPCs, which reveals that they are modular and repetitive assemblies of subunits referred to as nucleoporins, associated into stable subcomplexes and composed of a limited set of protein domains, including phenylalanine-glycine (FG) repeats and membrane-interacting domains. The outcome of investigations on nucleocytoplasmic trafficking will then be detailed, showing how it involves a limited number of molecular factors and common mechanisms, namely (i) indirect association of cargos with nuclear pores through receptors in the donor compartment, (ii) progression within the channel through dynamic hydrophobic interactions with FG-Nups, and (iii) NTPase-driven remodeling of transport complexes in the target compartment. Finally, we also discuss the outcome of more recent studies, which indicate that NPCs and the transport machinery are dynamic and versatile devices, whose biogenesis is tightly coordinated with the cell cycle, and which carry nonconventional duties, in particular, in mitosis, gene expression, and genetic stability.
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Affiliation(s)
- Aurélie G Floch
- Institut Jacques Monod, CNRS, UMR 7592, Univ. Paris Diderot, Sorbonne Paris Cité, F-75205 Paris, France; Ecole Doctorale Gènes Génomes Cellules, Université Paris Sud-11, Orsay, France
| | - Benoit Palancade
- Institut Jacques Monod, CNRS, UMR 7592, Univ. Paris Diderot, Sorbonne Paris Cité, F-75205 Paris, France
| | - Valérie Doye
- Institut Jacques Monod, CNRS, UMR 7592, Univ. Paris Diderot, Sorbonne Paris Cité, F-75205 Paris, France
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48
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Li A, Zou F, Fu H, Cui G, Yan Y, Wu Q, Gu X. Upregulation of CRM1 relates to neuronal apoptosis after traumatic brain injury in adult rats. J Mol Neurosci 2013; 51:208-18. [PMID: 23494640 DOI: 10.1007/s12031-013-9994-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2012] [Accepted: 03/04/2013] [Indexed: 12/11/2022]
Abstract
Traumatic brain injury (TBI) initiates a complex series of neurochemical and signaling changes that leads to neuronal dysfunction and over-reactive astrocytes. There is increasing evidence that CRM1 mediated P27(Kip1), which is a potent inhibitor of G1 cyclin-dependent kinases complexes, nuclear export-dependent or -independent Jab1/CSN5, and cytoplasmic degradation in cells. Up to now, the function of CRM1 in central nervous system (CNS) is still with limited acquaintance. In our study, to investigate whether CRM1 is involved in CNS lesion, we performed a TBI model in adult rats. Western blot and RT-PCR analysis revealed that the level of protein and mRNA of CRM1 increased in ipsilateral brain cortex in comparison to the contralateral. Immunohistochemistry and immunofluorescence double labeling indicated that CRM1 was shutting into nucleus around the wound, and increased CRM1 co-localized with P27(Kip1). Terminal deoxynucleotidyl transferase deoxy-UTP-nick end labeling (TUNEL) staining suggested that CRM1 was involved in neuronal apoptosis after brain injury. We also investigated co-localization of CRM1 and active-caspase-3 in the ipsilateral brain cortex. In addition, the expression patterns of Bax and active-caspase-3 were parallel with that of CRM1. Based on our data, we suggested that CRM1 might play an important role in neuronal apoptosis following TBI, and might provide a basis for the further study on its role in regulating the expression of P27(Kip1) and cell cycle re-entry in TBI.
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Affiliation(s)
- Aihong Li
- Department of Neurology, Affiliated Hospital of Nantong University, Nantong, Jiangsu, 226001, People's Republic of China
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49
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Li A, Zou F, Fu H, Cui G, Yan Y, Wu Q, Gu X. Upregulation of CRM1 relates to neuronal apoptosis after traumatic brain injury in adult rats. J Mol Neurosci 2013. [PMID: 23494640 DOI: 10.1007/s12031−013−9994−7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
Traumatic brain injury (TBI) initiates a complex series of neurochemical and signaling changes that leads to neuronal dysfunction and over-reactive astrocytes. There is increasing evidence that CRM1 mediated P27(Kip1), which is a potent inhibitor of G1 cyclin-dependent kinases complexes, nuclear export-dependent or -independent Jab1/CSN5, and cytoplasmic degradation in cells. Up to now, the function of CRM1 in central nervous system (CNS) is still with limited acquaintance. In our study, to investigate whether CRM1 is involved in CNS lesion, we performed a TBI model in adult rats. Western blot and RT-PCR analysis revealed that the level of protein and mRNA of CRM1 increased in ipsilateral brain cortex in comparison to the contralateral. Immunohistochemistry and immunofluorescence double labeling indicated that CRM1 was shutting into nucleus around the wound, and increased CRM1 co-localized with P27(Kip1). Terminal deoxynucleotidyl transferase deoxy-UTP-nick end labeling (TUNEL) staining suggested that CRM1 was involved in neuronal apoptosis after brain injury. We also investigated co-localization of CRM1 and active-caspase-3 in the ipsilateral brain cortex. In addition, the expression patterns of Bax and active-caspase-3 were parallel with that of CRM1. Based on our data, we suggested that CRM1 might play an important role in neuronal apoptosis following TBI, and might provide a basis for the further study on its role in regulating the expression of P27(Kip1) and cell cycle re-entry in TBI.
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Affiliation(s)
- Aihong Li
- Department of Neurology, Affiliated Hospital of Nantong University, Nantong, Jiangsu, 226001, People's Republic of China
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50
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Atkinson CE, Mattheyses AL, Kampmann M, Simon SM. Conserved spatial organization of FG domains in the nuclear pore complex. Biophys J 2013; 104:37-50. [PMID: 23332057 DOI: 10.1016/j.bpj.2012.11.3823] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Revised: 10/31/2012] [Accepted: 11/02/2012] [Indexed: 10/27/2022] Open
Abstract
Selective transport through the nuclear pore complex (NPC) requires nucleoporins containing natively unfolded phenylalanine-glycine (FG) domains. Several differing models for their dynamics within the pore have been proposed. We characterize the behavior of the FG nucleoporins in vivo using polarized fluorescence microscopy. Using nucleoporins tagged with green fluorescent protein along their FG domains, we show that some of these proteins are ordered, indicating an overall orientational organization within the NPC. This orientational ordering of the FG domains depends on their specific context within the NPC, but is independent of active transport and cargo load. For most nups, behavior does not depend on the FG motifs. These data support a model whereby local geometry constrains the orientational organization of the FG nups. Intriguingly, homologous yeast and mammalian proteins show conserved behavior, suggesting functional relevance. Our findings have implications for mechanistic models of NPC transport.
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Affiliation(s)
- Claire E Atkinson
- Laboratory of Cellular Biophysics, The Rockefeller University, New York, New York, USA
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