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Chen G, Yang J, Wu Y, Wang H, Zhang X, Feng G. A CRM1-dependent nuclear export signal in Autographa californica multiple nucleopolyhedrovirus Ac93 is important for the formation of intranuclear microvesicles. J Virol 2024; 98:e0029924. [PMID: 38557225 PMCID: PMC11092359 DOI: 10.1128/jvi.00299-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Accepted: 03/10/2024] [Indexed: 04/04/2024] Open
Abstract
Autographa californica multiple nucleopolyhedrovirus (AcMNPV) Ac93 is highly conserved in all sequenced baculovirus genomes, and it plays important roles in both the nuclear egress of nucleocapsids and the formation of intranuclear microvesicles. In this study, we characterized a cellular CRM1-dependent nuclear export signal (NES) of AcMNPV Ac93. Bioinformatic analysis revealed that AcMNPV Ac93 may contain an NES at amino acids 115-125. Green fluorescent protein (GFP) fused to the NES (GFP:NES) of AcMNPV Ac93 is localized to the cytoplasm of transfected cells. Multiple point mutation analysis demonstrated that NES is important for the nuclear export of GFP:NES. Bimolecular fluorescence complementation experiments and co-immunoprecipitation assays confirmed that Ac93 interacts with Spodoptera frugiperda CRM1 (SfCRM1). However, AcMNPV Ac34 inhibits cellular CRM1-dependent nuclear export of GFP:NES. To determine whether the NES in AcMNPV Ac93 is important for the formation of intranuclear microvesicles, an ac93-null AcMNPV bacmid was constructed; the wild-type and NES-mutated Ac93 were reinserted into the ac93-null AcMNPV bacmid. Immunofluorescence analysis showed that Ac93 and SfCRM1 were predominantly colocalized at intranuclear microvesicles in infected cells, while the construct containing point mutations at residues 123 and 125 of Ac93 resulted in a defect in budded virus production and the abolishment of intranuclear microvesicles. Together, these data demonstrate that Ac93 contains a functional NES, which is required for the production of progeny viruses and the formation of intranuclear microvesicles.IMPORTANCEAutographa californica multiple nucleopolyhedrovirus (AcMNPV) Ac93 is important for the formation of intranuclear microvesicles. However, how the baculovirus manipulates Ac93 for the formation of intranuclear microvesicles is unclear. In this study, we identified a nuclear export signal (NES) at amino acids 115-125 of AcMNPV Ac93. Our results showed that the NES is required for the interaction between Ac93 and Spodoptera frugiperda CRM1 (SfCRM1). However, AcMNPV Ac34 inhibits the nuclear export of green fluorescent protein fused to the NES. Our analysis revealed that Ac93 and SfCRM1 were predominantly colocalized at intranuclear microvesicles in AcMNPV-infected cells. Together, our results indicate that Ac93 participates in the formation of intranuclear microvesicles via the Ac93 NES-mediated CRM1 pathway.
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Affiliation(s)
- Guoqing Chen
- State Key Laboratory of Rice Biology and Breeding, China National Rice Research Institute, Hangzhou, China
| | - Jing Yang
- State Key Laboratory of Rice Biology and Breeding, China National Rice Research Institute, Hangzhou, China
| | - Yihong Wu
- State Key Laboratory of Rice Biology and Breeding, China National Rice Research Institute, Hangzhou, China
| | - Haoran Wang
- State Key Laboratory of Rice Biology and Breeding, China National Rice Research Institute, Hangzhou, China
| | - Xinxin Zhang
- State Key Laboratory of Rice Biology and Breeding, China National Rice Research Institute, Hangzhou, China
| | - Guozhong Feng
- State Key Laboratory of Rice Biology and Breeding, China National Rice Research Institute, Hangzhou, China
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2
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Behrens RT, Sherer NM. Retroviral hijacking of host transport pathways for genome nuclear export. mBio 2023; 14:e0007023. [PMID: 37909783 PMCID: PMC10746203 DOI: 10.1128/mbio.00070-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2023] Open
Abstract
Recent advances in the study of virus-cell interactions have improved our understanding of how viruses that replicate their genomes in the nucleus (e.g., retroviruses, hepadnaviruses, herpesviruses, and a subset of RNA viruses) hijack cellular pathways to export these genomes to the cytoplasm where they access virion egress pathways. These findings shed light on novel aspects of viral life cycles relevant to the development of new antiviral strategies and can yield new tractable, virus-based tools for exposing additional secrets of the cell. The goal of this review is to summarize defined and emerging modes of virus-host interactions that drive the transit of viral genomes out of the nucleus across the nuclear envelope barrier, with an emphasis on retroviruses that are most extensively studied. In this context, we prioritize discussion of recent progress in understanding the trafficking and function of the human immunodeficiency virus type 1 Rev protein, exemplifying a relatively refined example of stepwise, cooperativity-driven viral subversion of multi-subunit host transport receptor complexes.
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Affiliation(s)
- Ryan T. Behrens
- Department of Pathology and Laboratory Medicine, University of Wisconsin, Madison, Wisconsin, USA
| | - Nathan M. Sherer
- McArdle Laboratory for Cancer Research and Carbone Cancer Center, University of Wisconsin, Madison, Wisconsin, USA
- Institute for Molecular Virology, University of Wisconsin, Madison, Wisconsin, USA
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3
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Yang Y, Guo L, Chen L, Gong B, Jia D, Sun Q. Nuclear transport proteins: structure, function, and disease relevance. Signal Transduct Target Ther 2023; 8:425. [PMID: 37945593 PMCID: PMC10636164 DOI: 10.1038/s41392-023-01649-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2023] [Revised: 09/13/2023] [Accepted: 09/14/2023] [Indexed: 11/12/2023] Open
Abstract
Proper subcellular localization is crucial for the functioning of biomacromolecules, including proteins and RNAs. Nuclear transport is a fundamental cellular process that regulates the localization of many macromolecules within the nuclear or cytoplasmic compartments. In humans, approximately 60 proteins are involved in nuclear transport, including nucleoporins that form membrane-embedded nuclear pore complexes, karyopherins that transport cargoes through these complexes, and Ran system proteins that ensure directed and rapid transport. Many of these nuclear transport proteins play additional and essential roles in mitosis, biomolecular condensation, and gene transcription. Dysregulation of nuclear transport is linked to major human diseases such as cancer, neurodegenerative diseases, and viral infections. Selinexor (KPT-330), an inhibitor targeting the nuclear export factor XPO1 (also known as CRM1), was approved in 2019 to treat two types of blood cancers, and dozens of clinical trials of are ongoing. This review summarizes approximately three decades of research data in this field but focuses on the structure and function of individual nuclear transport proteins from recent studies, providing a cutting-edge and holistic view on the role of nuclear transport proteins in health and disease. In-depth knowledge of this rapidly evolving field has the potential to bring new insights into fundamental biology, pathogenic mechanisms, and therapeutic approaches.
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Affiliation(s)
- Yang Yang
- Department of Pulmonary and Critical Care Medicine, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
| | - Lu Guo
- Department of Pulmonary and Critical Care Medicine, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
| | - Lin Chen
- Department of Pulmonary and Critical Care Medicine, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
| | - Bo Gong
- The Key Laboratory for Human Disease Gene Study of Sichuan Province and Department of Laboratory Medicine, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
- Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu, China
| | - Da Jia
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Pediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy, Sichuan University, Chengdu, China.
| | - Qingxiang Sun
- Department of Pulmonary and Critical Care Medicine, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China.
- Department of Pathology, State Key Laboratory of Biotherapy and Cancer Centre, West China Hospital, Sichuan University, and Collaborative Innovation Centre of Biotherapy, Chengdu, China.
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4
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Falini B. NPM1-mutated acute myeloid leukemia: New pathogenetic and therapeutic insights and open questions. Am J Hematol 2023; 98:1452-1464. [PMID: 37317978 DOI: 10.1002/ajh.26989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Accepted: 06/02/2023] [Indexed: 06/16/2023]
Abstract
The nucleophosmin (NPM1) gene encodes for a multifunctional chaperone protein that is localized in the nucleolus but continuously shuttles between the nucleus and cytoplasm. NPM1 mutations occur in about one-third of AML, are AML-specific, usually involve exon 12 and are frequently associated with FLT3-ITD, DNMT3A, TET2, and IDH1/2 mutations. Because of its unique molecular and clinico-pathological features, NPM1-mutated AML is regarded as a distinct leukemia entity in both the International Consensus Classification (ICC) and the 5th edition of the World Health Organization (WHO) classification of myeloid neoplasms. All NPM1 mutations generate leukemic mutants that are aberrantly exported in the cytoplasm of the leukemic cells and are relevant to the pathogenesis of the disease. Here, we focus on recently identified functions of the NPM1 mutant at chromatin level and its relevance in driving HOX/MEIS gene expression. We also discuss yet controversial issues of the ICC/WHO classifications, including the biological and clinical significance of therapy-related NPM1-mutated AML and the relevance of blasts percentage in defining NPM1-mutated AML. Finally, we address the impact of new targeted therapies in NPM1-mutated AML with focus on CAR T cells directed against NPM1/HLA neoepitopes, as well as XPO1 and menin inhibitors.
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Affiliation(s)
- Brunangelo Falini
- Institute of Hematology and Center for Hemato-Oncological Research (CREO), University of Perugia and Santa Maria della Misericordia Hospital, Perugia, Italy
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5
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Balasubramanian SK, Azmi AS, Maciejewski J. Selective inhibition of nuclear export: a promising approach in the shifting treatment paradigms for hematological neoplasms. Leukemia 2022; 36:601-612. [PMID: 35091658 PMCID: PMC8885406 DOI: 10.1038/s41375-021-01483-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 11/04/2021] [Accepted: 11/16/2021] [Indexed: 12/12/2022]
Abstract
Novel targeted therapeutics alone or in rational combinations are likely to dominate the future management of various hematological neoplasms. However, the challenges currently faced are the molecular heterogeneity in driver lesions and genetic plasticity leading to multiple resistance pathways. Thus, progress has overall been gradual. For example, despite the advent of targeted agents against actionable drivers like FLT3 in acute myeloid leukemia (AML), the prognosis remains suboptimal in newly diagnosed and dismal in the relapsed/refractory (R/R) setting, due to other molecular abnormalities contributing to inherent and acquired treatment resistance. Nuclear export inhibitors are of keen interest because they can inhibit several active tumorigenic processes simultaneously and also synergize with other targeted drugs and chemotherapy. XPO1 (or CRM1, chromosome maintenance region 1) is one of the most studied exportins involved in transporting critical cargoes, including tumor suppressor proteins like p27, p53, and RB1. Apart from the TSP cargo transport and its role in drug resistance, XPO1 inhibition results in retention of master transcription factors essential for cell differentiation, cell survival, and autophagy, rendering cells more susceptible to the effects of other antineoplastic agents, including targeted therapies. This review will dissect the role of XPO1 inhibition in hematological neoplasms, focusing on mechanistic insights gleaned mainly from work with SINE compounds. Future potential combinatorial strategies will be discussed.
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Affiliation(s)
| | - Asfar S Azmi
- Department of Oncology, Wayne State University School of Medicine, Detroit, USA
| | - Jaroslaw Maciejewski
- Translational Hematology and Oncology Research, Cleveland Clinic, Cleveland, USA.
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6
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Wing CE, Fung HYJ, Chook YM. Karyopherin-mediated nucleocytoplasmic transport. Nat Rev Mol Cell Biol 2022; 23:307-328. [PMID: 35058649 PMCID: PMC10101760 DOI: 10.1038/s41580-021-00446-7] [Citation(s) in RCA: 107] [Impact Index Per Article: 53.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/09/2021] [Indexed: 12/25/2022]
Abstract
Efficient and regulated nucleocytoplasmic trafficking of macromolecules to the correct subcellular compartment is critical for proper functions of the eukaryotic cell. The majority of the macromolecular traffic across the nuclear pores is mediated by the Karyopherin-β (or Kap) family of nuclear transport receptors. Work over more than two decades has shed considerable light on how the different Kap family members bring their respective cargoes into the nucleus or the cytoplasm in efficient and highly regulated manners. In this Review, we overview the main features and established functions of Kap family members, describe how Kaps recognize their cargoes and discuss the different ways in which these Kap-cargo interactions can be regulated, highlighting new findings and open questions. We also describe current knowledge of the import and export of the components of three large gene expression machines - the core replisome, RNA polymerase II and the ribosome - pointing out the questions that persist about how such large macromolecular complexes are trafficked to serve their function in a designated subcellular location.
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7
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Liu S, Qiao W, Sun Q, Luo Y. Chromosome Region Maintenance 1 (XPO1/CRM1) as an Anticancer Target and Discovery of Its Inhibitor. J Med Chem 2021; 64:15534-15548. [PMID: 34669417 DOI: 10.1021/acs.jmedchem.1c01145] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Chromosome region maintenance 1 (CRM1) is a major nuclear export receptor protein and contributes to cell homeostasis by mediating the transport of cargo from the nucleus to the cytoplasm. CRM1 is a therapeutic target comprised of several tumor types, including osteosarcoma, multiple myeloma, gliomas, and pancreatic cancer. In the past decade, dozens of CRM1 inhibitors have been discovered and developed, including KPT-330, which received FDA approval for multiple myeloma (MM) and diffuse large B-cell lymphoma (DLBCL) in 2019 and 2020, respectively. This review summarizes the biological functions of CRM1, the current understanding of the role CRM1 plays in cancer, the discovery of CRM1 small-molecule inhibitors, preclinical and clinical studies on KPT-330, and other recently developed inhibitors. A new CRM1 inhibition mechanism and structural dynamics are discussed. Through this review, we hope to guide the future design and optimization of CRM1 inhibitors.
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Affiliation(s)
- Song Liu
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Wenliang Qiao
- Lung Cancer Center, Laboratory of Lung Cancer, West China Medical School, Sichuan University, Chengdu 610041, China
| | - Qingxiang Sun
- State Key Laboratory of Biotherapy, Department of Pathology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Youfu Luo
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu 610041, China
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8
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Aumann WK, Heath JL, Conway AE, Sze SGK, Gupta VK, Kazi RR, Tope DR, Wechsler DS, Lavau CP. Fusion of the CRM1 nuclear export receptor to AF10 causes leukemia and transcriptional activation of HOXA genes. Leukemia 2021; 35:876-880. [PMID: 32733011 PMCID: PMC7854800 DOI: 10.1038/s41375-020-0998-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 07/09/2020] [Accepted: 07/21/2020] [Indexed: 11/16/2022]
MESH Headings
- Active Transport, Cell Nucleus
- Animals
- Apoptosis
- Cell Proliferation
- Cells, Cultured
- Gene Expression Regulation, Leukemic
- Hematopoietic Stem Cells/metabolism
- Hematopoietic Stem Cells/pathology
- Homeodomain Proteins/genetics
- Homeodomain Proteins/metabolism
- Karyopherins/genetics
- Karyopherins/metabolism
- Leukemia, Experimental/etiology
- Leukemia, Experimental/metabolism
- Leukemia, Experimental/pathology
- Mice
- Oncogene Proteins, Fusion/genetics
- Oncogene Proteins, Fusion/metabolism
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/metabolism
- Transcription Factors/genetics
- Transcription Factors/metabolism
- Transcriptional Activation
- Exportin 1 Protein
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Affiliation(s)
- Waitman K Aumann
- Aflac Cancer & Blood Disorders Center, Children's Healthcare of Atlanta, Atlanta, GA, USA
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Jessica L Heath
- Department of Pediatrics, Biochemistry, University of Vermont; University of Vermont Children's Hospital; Vermont Cancer Center, Burlington, VT, USA
| | - Amanda E Conway
- National Institute of Environmental Health Sciences (NIEHS), Research Triangle Park, Durham, NC, USA
| | | | - Veerain K Gupta
- Department of Pediatrics, Division of Pediatric Hematology-Oncology, Duke University Medical Center, Durham, NC, USA
| | - Rafi R Kazi
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Donald R Tope
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Daniel S Wechsler
- Aflac Cancer & Blood Disorders Center, Children's Healthcare of Atlanta, Atlanta, GA, USA.
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA.
| | - Catherine P Lavau
- Department of Neurosurgery, Duke University Medical Center, Durham, NC, USA.
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9
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Walker JS, Hing ZA, Harrington B, Baumhardt J, Ozer HG, Lehman A, Giacopelli B, Beaver L, Williams K, Skinner JN, Cempre CB, Sun Q, Shacham S, Stromberg BR, Summers MK, Abruzzo LV, Rassenti L, Kipps TJ, Parikh S, Kay NE, Rogers KA, Woyach JA, Coppola V, Chook YM, Oakes C, Byrd JC, Lapalombella R. Recurrent XPO1 mutations alter pathogenesis of chronic lymphocytic leukemia. J Hematol Oncol 2021; 14:17. [PMID: 33451349 PMCID: PMC7809770 DOI: 10.1186/s13045-021-01032-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Accepted: 01/01/2021] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Exportin 1 (XPO1/CRM1) is a key mediator of nuclear export with relevance to multiple cancers, including chronic lymphocytic leukemia (CLL). Whole exome sequencing has identified hot-spot somatic XPO1 point mutations which we found to disrupt highly conserved biophysical interactions in the NES-binding groove, conferring novel cargo-binding abilities and forcing cellular mis-localization of critical regulators. However, the pathogenic role played by change-in-function XPO1 mutations in CLL is not fully understood. METHODS We performed a large, multi-center retrospective analysis of CLL cases (N = 1286) to correlate nonsynonymous mutations in XPO1 (predominantly E571K or E571G; n = 72) with genetic and epigenetic features contributing to the overall outcomes in these patients. We then established a mouse model with over-expression of wildtype (wt) or mutant (E571K or E571G) XPO1 restricted to the B cell compartment (Eµ-XPO1). Eµ-XPO1 mice were then crossed with the Eµ-TCL1 CLL mouse model. Lastly, we determined crystal structures of XPO1 (wt or E571K) bound to several selective inhibitors of nuclear export (SINE) molecules (KPT-185, KPT-330/Selinexor, and KPT-8602/Eltanexor). RESULTS We report that nonsynonymous mutations in XPO1 associate with high risk genetic and epigenetic features and accelerated CLL progression. Using the newly-generated Eµ-XPO1 mouse model, we found that constitutive B-cell over-expression of wt or mutant XPO1 could affect development of a CLL-like disease in aged mice. Furthermore, concurrent B-cell expression of XPO1 with E571K or E571G mutations and TCL1 accelerated the rate of leukemogenesis relative to that of Eµ-TCL1 mice. Lastly, crystal structures of E571 or E571K-XPO1 bound to SINEs, including Selinexor, are highly similar, suggesting that the activity of this class of compounds will not be affected by XPO1 mutations at E571 in patients with CLL. CONCLUSIONS These findings indicate that mutations in XPO1 at E571 can drive leukemogenesis by priming the pre-neoplastic lymphocytes for acquisition of additional genetic and epigenetic abnormalities that collectively result in neoplastic transformation.
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Affiliation(s)
- Janek S Walker
- Division of Hematology, Department of Internal Medicine, The Ohio State University, 460 OSUCCC, 410 West 12th Avenue, Columbus, OH, 43210, USA
| | - Zachary A Hing
- Division of Hematology, Department of Internal Medicine, The Ohio State University, 460 OSUCCC, 410 West 12th Avenue, Columbus, OH, 43210, USA
| | - Bonnie Harrington
- Division of Hematology, Department of Internal Medicine, The Ohio State University, 460 OSUCCC, 410 West 12th Avenue, Columbus, OH, 43210, USA
- Department of Veterinary Biosciences, The Ohio State University, Columbus, OH, USA
| | - Jordan Baumhardt
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Hatice Gulcin Ozer
- Department of Biomedical Informatics, The Ohio State University, Columbus, OH, USA
| | - Amy Lehman
- Center for Biostatistics, Department of Biomedical Informatics, The Ohio State University, Columbus, OH, USA
| | - Brian Giacopelli
- Division of Hematology, Department of Internal Medicine, The Ohio State University, 460 OSUCCC, 410 West 12th Avenue, Columbus, OH, 43210, USA
| | - Larry Beaver
- Division of Hematology, Department of Internal Medicine, The Ohio State University, 460 OSUCCC, 410 West 12th Avenue, Columbus, OH, 43210, USA
| | - Katie Williams
- Division of Hematology, Department of Internal Medicine, The Ohio State University, 460 OSUCCC, 410 West 12th Avenue, Columbus, OH, 43210, USA
| | - Jordan N Skinner
- Division of Hematology, Department of Internal Medicine, The Ohio State University, 460 OSUCCC, 410 West 12th Avenue, Columbus, OH, 43210, USA
| | - Casey B Cempre
- Division of Hematology, Department of Internal Medicine, The Ohio State University, 460 OSUCCC, 410 West 12th Avenue, Columbus, OH, 43210, USA
| | - Qingxiang Sun
- Department of Pathology and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, 610041, China
| | | | - Benjamin R Stromberg
- Department of Radiation Oncology, Arthur G James Comprehensive Cancer Center and Richard L. Solove Research Institute, The Ohio State University, Columbus, OH, USA
| | - Matthew K Summers
- Department of Radiation Oncology, Arthur G James Comprehensive Cancer Center and Richard L. Solove Research Institute, The Ohio State University, Columbus, OH, USA
| | - Lynne V Abruzzo
- Department of Pathology, The Ohio State University, Columbus, OH, USA
| | - Laura Rassenti
- Department of Medicine, Division of Hematology, University of California-San Diego School of Medicine, San Diego, CA, USA
| | - Thomas J Kipps
- Department of Medicine, Division of Hematology, University of California-San Diego School of Medicine, San Diego, CA, USA
| | - Sameer Parikh
- Division of Hematology, Department of Medicine, Mayo Clinic, Rochester, MN, USA
| | - Neil E Kay
- Division of Hematology, Department of Medicine, Mayo Clinic, Rochester, MN, USA
| | - Kerry A Rogers
- Division of Hematology, Department of Internal Medicine, The Ohio State University, 460 OSUCCC, 410 West 12th Avenue, Columbus, OH, 43210, USA
| | - Jennifer A Woyach
- Division of Hematology, Department of Internal Medicine, The Ohio State University, 460 OSUCCC, 410 West 12th Avenue, Columbus, OH, 43210, USA
| | - Vincenzo Coppola
- Department of Cancer Biology and Genetics, The Ohio State University College of Medicine, Columbus, OH, USA
- Genetically Engineered Mouse Modeling Core, The Ohio State University and Arthur G. James Comprehensive Cancer Center, Columbus, OH, USA
| | - Yuh Min Chook
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Christopher Oakes
- Division of Hematology, Department of Internal Medicine, The Ohio State University, 460 OSUCCC, 410 West 12th Avenue, Columbus, OH, 43210, USA
| | - John C Byrd
- Division of Hematology, Department of Internal Medicine, The Ohio State University, 460 OSUCCC, 410 West 12th Avenue, Columbus, OH, 43210, USA
- Division of Medicinal Chemistry, College of Pharmacy, The Ohio State University, Columbus, OH, USA
| | - Rosa Lapalombella
- Division of Hematology, Department of Internal Medicine, The Ohio State University, 460 OSUCCC, 410 West 12th Avenue, Columbus, OH, 43210, USA.
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10
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The Nuclear Pore Complex and mRNA Export in Cancer. Cancers (Basel) 2020; 13:cancers13010042. [PMID: 33375634 PMCID: PMC7796397 DOI: 10.3390/cancers13010042] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 12/11/2020] [Accepted: 12/22/2020] [Indexed: 02/07/2023] Open
Abstract
Export of mRNAs from the nucleus to the cytoplasm is a key regulatory step in the expression of proteins. mRNAs are transported through the nuclear pore complex (NPC). Export of mRNAs responds to a variety of cellular stimuli and stresses. Revelations of the specific effects elicited by NPC components and associated co-factors provides a molecular basis for the export of selected RNAs, independent of bulk mRNA export. Aberrant RNA export has been observed in primary human cancer specimens. These cargo RNAs encode factors involved in nearly all facets of malignancy. Indeed, the NPC components involved in RNA export as well as the RNA export machinery can be found to be dysregulated, mutated, or impacted by chromosomal translocations in cancer. The basic mechanisms associated with RNA export with relation to export machinery and relevant NPC components are described. Therapeutic strategies targeting this machinery in clinical trials is also discussed. These findings firmly position RNA export as a targetable feature of cancer along with transcription and translation.
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11
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Martin APJ, Camonis JH. The hippo kinase STK38 ensures functionality of XPO1. Cell Cycle 2020; 19:2982-2995. [PMID: 33017560 PMCID: PMC7714482 DOI: 10.1080/15384101.2020.1826619] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Revised: 08/06/2020] [Accepted: 08/08/2020] [Indexed: 10/23/2022] Open
Abstract
The proper segregation of basic elements such as the compartmentalization of the genome and the shuttling of macromolecules between the nucleus and the cytoplasm is a crucial mechanism for homeostasis maintenance in eukaryotic cells. XPO1 (Exportin 1) is the major nuclear export receptor and is required for the export of proteins and RNAs out of the nucleus. STK38 (also known as NDR1) is a Hippo pathway serine/threonine kinase with multifarious functions in normal and cancer cells. In this review, we summarize the history of the discovery of the nucleo/cytoplasmic shuttling of proteins and focus on the major actor of nuclear export: XPO1. After describing the molecular events required for XPO1-mediated nuclear export of proteins, we introduce the Hippo pathway STK38 kinase, synthetize its regulation mechanisms as well as its biological functions in both normal and cancer cells, and finally its intersection with XPO1 biology. We discuss the recently identified mechanism of XPO1 activation by phosphorylation of XPO1_S1055 by STK38 and contextualize this finding according to the biological functions previously reported for both XPO1 and STK38, including the second identity of STK38 as an autophagy regulator. Finally, we phrase this newly identified activation mechanism into the general nuclear export machinery and examine the possible outcomes of nuclear export inhibition in cancer treatment.
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Affiliation(s)
- Alexandre PJ Martin
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, USA
| | - Jacques H Camonis
- Inserm U830, Institut Curie, Centre de Recherche, Paris Sciences et Lettres Research University, Paris, France
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12
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Sendino M, Omaetxebarria MJ, Prieto G, Rodriguez JA. Using a Simple Cellular Assay to Map NES Motifs in Cancer-Related Proteins, Gain Insight into CRM1-Mediated NES Export, and Search for NES-Harboring Micropeptides. Int J Mol Sci 2020; 21:E6341. [PMID: 32882917 PMCID: PMC7503480 DOI: 10.3390/ijms21176341] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 08/24/2020] [Accepted: 08/26/2020] [Indexed: 12/26/2022] Open
Abstract
The nuclear export receptor CRM1 (XPO1) recognizes and binds specific sequence motifs termed nuclear export signals (NESs) in cargo proteins. About 200 NES motifs have been identified, but over a thousand human proteins are potential CRM1 cargos, and most of their NESs remain to be identified. On the other hand, the interaction of NES peptides with the "NES-binding groove" of CRM1 was studied in detail using structural and biochemical analyses, but a better understanding of CRM1 function requires further investigation of how the results from these in vitro studies translate into actual NES export in a cellular context. Here we show that a simple cellular assay, based on a recently described reporter (SRVB/A), can be applied to identify novel potential NESs motifs, and to obtain relevant information on different aspects of CRM1-mediated NES export. Using cellular assays, we first map 19 new sequence motifs with nuclear export activity in 14 cancer-related proteins that are potential CRM1 cargos. Next, we investigate the effect of mutations in individual NES-binding groove residues, providing further insight into CRM1-mediated NES export. Finally, we extend the search for CRM1-dependent NESs to a recently uncovered, but potentially vast, set of small proteins called micropeptides. By doing so, we report the first NES-harboring human micropeptides.
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Affiliation(s)
- Maria Sendino
- Department of Genetics, Physical Anthropology and Animal Physiology, University of the Basque Country (UPV/EHU), 48940 Leioa, Spain;
| | - Miren Josu Omaetxebarria
- Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), 48940 Leioa, Spain;
| | - Gorka Prieto
- Department of Communications Engineering, University of the Basque Country (UPV/EHU), 48013 Bilbao, Spain;
| | - Jose Antonio Rodriguez
- Department of Genetics, Physical Anthropology and Animal Physiology, University of the Basque Country (UPV/EHU), 48940 Leioa, Spain;
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13
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Richard S, Richter J, Jagannath S. Selinexor: a first-in-class SINE compound for treatment of relapsed refractory multiple myeloma. Future Oncol 2020; 16:1331-1350. [PMID: 32511022 DOI: 10.2217/fon-2020-0054] [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] [Indexed: 12/14/2022] Open
Abstract
The progression of multiple myeloma is accompanied by complex cytogenetic and epigenetic alterations that include mutation or functional inactivation of tumor suppressor proteins and overexpression of oncoproteins. Patients whose myeloma is refractory to the three major classes of drugs including immunomodulatory agents, proteasome inhibitors and anti-CD38 monoclonal antibodies have a very poor prognosis. Drugs with novel mechanisms of action that can bypass resistance mechanisms are sorely needed for this group of patients. Selinexor represents a novel, oral agent with an innovative mechanism of action that offers a significant therapeutic advance in this group of heavily treated patients. Moreover, this novel mechanism may provide additional options for patients with less refractory disease.
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Affiliation(s)
- Shambavi Richard
- Icahn School of Medicine at Mount Sinai Tisch Cancer Institute, New York 10029, USA
| | - Joshua Richter
- Icahn School of Medicine at Mount Sinai Tisch Cancer Institute, New York 10029, USA
| | - Sundar Jagannath
- Icahn School of Medicine at Mount Sinai Tisch Cancer Institute, New York 10029, USA
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14
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Walker JS, Garzon R, Lapalombella R. Selinexor for advanced hematologic malignancies. Leuk Lymphoma 2020; 61:2335-2350. [DOI: 10.1080/10428194.2020.1775210] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Janek S. Walker
- Division of Hematology, Department of Internal Medicine, The Ohio State University, Columbus, OH, USA
| | - Ramiro Garzon
- Division of Hematology, Department of Internal Medicine, The Ohio State University, Columbus, OH, USA
| | - Rosa Lapalombella
- Division of Hematology, Department of Internal Medicine, The Ohio State University, Columbus, OH, USA
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15
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Ferreira BI, Cautain B, Grenho I, Link W. Small Molecule Inhibitors of CRM1. Front Pharmacol 2020; 11:625. [PMID: 32574233 PMCID: PMC7221118 DOI: 10.3389/fphar.2020.00625] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 04/20/2020] [Indexed: 12/19/2022] Open
Abstract
The transport through the nuclear pore complex is used by cancer cells to evade tumor-suppressive mechanisms. Several tumor-suppressors have been shown to be excluded from the cell nucleus in cancer cells by the nuclear export receptor CRM1 and abnormal expression of CRM1 is oncogenic. Inhibition of CRM1 has long been postulated as potential approach for the treatment of cancer and to overcome therapy resistance. Furthermore, the nuclear export of viral components mediated by the CRM1 is crucial in various stages of the viral lifecycle and assembly of many viruses from diverse families, including coronavirus. However, the first nuclear export inhibitors failed or never entered into clinical trials. More recently CRM1 reemerged as a cancer target and a successful proof of concept was achieved with the clinical approval of Selinexor. The chemical complexity of natural products is a promising perspective for the discovery of new nuclear export inhibitors with a favorable toxicity profile. Several screening campaigns have been performed and several natural product-based nuclear export inhibitors have been identified. With this review we give an overview over the role of CRM1-mediated nuclear export in cancer and the effort made to identify and develop nuclear export inhibitors in particular from natural sources.
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Affiliation(s)
- Bibiana I Ferreira
- Centre for Biomedical Research (CBMR), University of Algarve, Faro, Portugal.,Regenerative Medicine Program, Department of Biomedical Sciences and Medicine, University of Algarve, Faro, Portugal.,Algarve Biomedical Center (ABC), University of Algarve, Faro, Portugal
| | - Bastien Cautain
- Fundacion MEDINA Parque tecnológico ciencias de la salud, Granada, Spain.,Evotec France, Toulouse, France
| | - Inês Grenho
- Centre for Biomedical Research (CBMR), University of Algarve, Faro, Portugal.,Regenerative Medicine Program, Department of Biomedical Sciences and Medicine, University of Algarve, Faro, Portugal.,Algarve Biomedical Center (ABC), University of Algarve, Faro, Portugal
| | - Wolfgang Link
- Instituto de Investigaciones Biomédicas "Alberto Sols" (CSIC-UAM), Madrid, Spain
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16
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Xu J, Sheng Z, Li F, Wang S, Yuan Y, Wang M, Yu Z. NEDD4 protects vascular endothelial cells against Angiotensin II-induced cell death via enhancement of XPO1-mediated nuclear export. Exp Cell Res 2019; 383:111505. [PMID: 31326389 DOI: 10.1016/j.yexcr.2019.111505] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 07/14/2019] [Accepted: 07/18/2019] [Indexed: 01/11/2023]
Abstract
NEDD4 is an E3 ubiquitin ligase containing the HECT domain, which regulates various cellular processes, but its role in vascular endothelial cells is unknown. In the present study, we found that NEDD4 bound directly to XPO1 by co-immunoprecipitation screening. In HUVECs (human umbilical vein endothelial cells), overexpression of NEDD4 reduced Ang II-induced ROS level and cell apoptosis. Ang II stimulation led to nuclear accumulation of cargoes, while overexpression of NEDD4 enhanced the XPO1-dependent nuclear export of its cargoes. KPT185, an inhibitor of XPO1, can abolished the protective effect of NEDD4 under Ang II treatment. In addition, NEDD4 could promote the interaction between XPO1 and RanBP3 via K63-linked ubiquitination of XPO1. These results suggested that NEDD4 played a protective role in vascular endothelial cell injury through regulating XPO1-mediated nuclear export.
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Affiliation(s)
- Jianning Xu
- Intensive Care Unit, The Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, 330006, China
| | - Zhiyong Sheng
- Intensive Care Unit, The Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, 330006, China
| | - Fuxin Li
- Intensive Care Unit, The Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, 330006, China
| | - Shu Wang
- Intensive Care Unit, The Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, 330006, China
| | - Ying Yuan
- Intensive Care Unit, The Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, 330006, China
| | - Meng Wang
- Intensive Care Unit, The Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, 330006, China
| | - Zhihong Yu
- Intensive Care Unit, The Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, 330006, China.
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17
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Ferreira PA. The coming-of-age of nucleocytoplasmic transport in motor neuron disease and neurodegeneration. Cell Mol Life Sci 2019; 76:2247-2273. [PMID: 30742233 PMCID: PMC6531325 DOI: 10.1007/s00018-019-03029-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 01/28/2019] [Indexed: 12/11/2022]
Abstract
The nuclear pore is the gatekeeper of nucleocytoplasmic transport and signaling through which a vast flux of information is continuously exchanged between the nuclear and cytoplasmic compartments to maintain cellular homeostasis. A unifying and organizing principle has recently emerged that cements the notion that several forms of amyotrophic lateral sclerosis (ALS), and growing number of other neurodegenerative diseases, co-opt the dysregulation of nucleocytoplasmic transport and that this impairment is a pathogenic driver of neurodegeneration. The understanding of shared pathomechanisms that underpin neurodegenerative diseases with impairments in nucleocytoplasmic transport and how these interface with current concepts of nucleocytoplasmic transport is bound to illuminate this fundamental biological process in a yet more physiological context. Here, I summarize unresolved questions and evidence and extend basic and critical concepts and challenges of nucleocytoplasmic transport and its role in the pathogenesis of neurodegenerative diseases, such as ALS. These principles will help to appreciate the roles of nucleocytoplasmic transport in the pathogenesis of ALS and other neurodegenerative diseases, and generate a framework for new ideas of the susceptibility of motoneurons, and possibly other neurons, to degeneration by dysregulation of nucleocytoplasmic transport.
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Affiliation(s)
- Paulo A Ferreira
- Duke University Medical Center, DUEC 3802, 2351 Erwin Road, Durham, NC, 27710, USA.
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18
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Funk C, Raschbichler V, Lieber D, Wetschky J, Arnold EK, Leimser J, Biggel M, Friedel CC, Ruzsics Z, Bailer SM. Comprehensive analysis of nuclear export of herpes simplex virus type 1 tegument proteins and their Epstein-Barr virus orthologs. Traffic 2019; 20:152-167. [PMID: 30548142 PMCID: PMC6590417 DOI: 10.1111/tra.12627] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2018] [Revised: 11/29/2018] [Accepted: 11/29/2018] [Indexed: 01/21/2023]
Abstract
Morphogenesis of herpesviral virions is initiated in the nucleus but completed in the cytoplasm. Mature virions contain more than 25 tegument proteins many of which perform both nuclear and cytoplasmic functions suggesting they shuttle between these compartments. While nuclear import of herpesviral proteins was shown to be crucial for viral propagation, active nuclear export and its functional impact are still poorly understood. To systematically analyze nuclear export of tegument proteins present in virions of Herpes simplex virus type 1 (HSV1) and Epstein-Barr virus (EBV), the Nuclear EXport Trapped by RAPamycin (NEX-TRAP) was applied. Nine of the 22 investigated HSV1 tegument proteins including pUL4, pUL7, pUL11, pUL13, pUL21, pUL37d11, pUL47, pUL48 and pUS2 as well as 2 out of 6 EBV orthologs harbor nuclear export activity. A functional leucine-rich nuclear export sequence (NES) recognized by the export factor CRM1/Xpo1 was identified in six of them. The comparison between experimental and bioinformatic data indicates that experimental validation of predicted NESs is required. Mutational analysis of the pUL48/VP16 NES revealed its importance for herpesviral propagation. Together our data suggest that nuclear export is an important feature of the herpesviral life cycle required to co-ordinate nuclear and cytoplasmic processes.
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Affiliation(s)
- Christina Funk
- Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB, Stuttgart, Germany
| | - Verena Raschbichler
- Max von Pettenkofer-Institute, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Diana Lieber
- Max von Pettenkofer-Institute, Ludwig-Maximilians-University Munich, Munich, Germany.,Institute of Virology, Ulm University Medical Center, Ulm, Germany
| | - Jens Wetschky
- Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB, Stuttgart, Germany
| | - Eileen K Arnold
- Institute of Interfacial Process Engineering and Plasma Technology, University of Stuttgart, Stuttgart, Germany
| | - Jacqueline Leimser
- Institute of Interfacial Process Engineering and Plasma Technology, University of Stuttgart, Stuttgart, Germany
| | - Michael Biggel
- Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB, Stuttgart, Germany
| | - Caroline C Friedel
- Institute for Informatics, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Zsolt Ruzsics
- Institute of Virology, Medical Center-University of Freiburg, Medical Faculty, University of Freiburg, Freiburg, Germany
| | - Susanne M Bailer
- Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB, Stuttgart, Germany.,Max von Pettenkofer-Institute, Ludwig-Maximilians-University Munich, Munich, Germany.,Institute of Interfacial Process Engineering and Plasma Technology, University of Stuttgart, Stuttgart, Germany
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19
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Yan D, Pomicter AD, Tantravahi S, Mason CC, Senina AV, Ahmann JM, Wang Q, Than H, Patel AB, Heaton WL, Eiring AM, Clair PM, Gantz KC, Redwine HM, Swierczek SI, Halverson BJ, Baloglu E, Shacham S, Khorashad JS, Kelley TW, Salama ME, Miles RR, Boucher KM, Prchal JT, O'Hare T, Deininger MW. Nuclear-Cytoplasmic Transport Is a Therapeutic Target in Myelofibrosis. Clin Cancer Res 2018; 25:2323-2335. [PMID: 30563936 DOI: 10.1158/1078-0432.ccr-18-0959] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 08/31/2018] [Accepted: 12/14/2018] [Indexed: 01/06/2023]
Abstract
PURPOSE Myelofibrosis is a hematopoietic stem cell neoplasm characterized by bone marrow reticulin fibrosis, extramedullary hematopoiesis, and frequent transformation to acute myeloid leukemia. Constitutive activation of JAK/STAT signaling through mutations in JAK2, CALR, or MPL is central to myelofibrosis pathogenesis. JAK inhibitors such as ruxolitinib reduce symptoms and improve quality of life, but are not curative and do not prevent leukemic transformation, defining a need to identify better therapeutic targets in myelofibrosis. EXPERIMENTAL DESIGN A short hairpin RNA library screening was performed on JAK2V617F-mutant HEL cells. Nuclear-cytoplasmic transport (NCT) genes including RAN and RANBP2 were among top candidates. JAK2V617F-mutant cell lines, human primary myelofibrosis CD34+ cells, and a retroviral JAK2V617F-driven myeloproliferative neoplasms mouse model were used to determine the effects of inhibiting NCT with selective inhibitors of nuclear export compounds KPT-330 (selinexor) or KPT-8602 (eltanexor). RESULTS JAK2V617F-mutant HEL, SET-2, and HEL cells resistant to JAK inhibition are exquisitely sensitive to RAN knockdown or pharmacologic inhibition by KPT-330 or KPT-8602. Inhibition of NCT selectively decreased viable cells and colony formation by myelofibrosis compared with cord blood CD34+ cells and enhanced ruxolitinib-mediated growth inhibition and apoptosis, both in newly diagnosed and ruxolitinib-exposed myelofibrosis cells. Inhibition of NCT in myelofibrosis CD34+ cells led to nuclear accumulation of p53. KPT-330 in combination with ruxolitinib-normalized white blood cells, hematocrit, spleen size, and architecture, and selectively reduced JAK2V617F-mutant cells in vivo. CONCLUSIONS Our data implicate NCT as a potential therapeutic target in myelofibrosis and provide a rationale for clinical evaluation in ruxolitinib-exposed patients with myelofibrosis.
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Affiliation(s)
- Dongqing Yan
- Huntsman Cancer Institute, The University of Utah, Salt Lake City, Utah
| | | | - Srinivas Tantravahi
- Huntsman Cancer Institute, The University of Utah, Salt Lake City, Utah.,Division of Hematology and Hematologic Malignancies, The University of Utah, Salt Lake City, Utah
| | - Clinton C Mason
- Department of Pediatrics, The University of Utah, Salt Lake City, Utah
| | - Anna V Senina
- Huntsman Cancer Institute, The University of Utah, Salt Lake City, Utah
| | - Jonathan M Ahmann
- Huntsman Cancer Institute, The University of Utah, Salt Lake City, Utah
| | - Qiang Wang
- Huntsman Cancer Institute, The University of Utah, Salt Lake City, Utah.,Department of Hematology, Nanfang Hospital, Southern Medical University
| | - Hein Than
- Huntsman Cancer Institute, The University of Utah, Salt Lake City, Utah.,Department of Haematology, Singapore General Hospital, Singapore
| | - Ami B Patel
- Huntsman Cancer Institute, The University of Utah, Salt Lake City, Utah.,Division of Hematology and Hematologic Malignancies, The University of Utah, Salt Lake City, Utah
| | - William L Heaton
- Huntsman Cancer Institute, The University of Utah, Salt Lake City, Utah
| | - Anna M Eiring
- Huntsman Cancer Institute, The University of Utah, Salt Lake City, Utah
| | - Phillip M Clair
- Huntsman Cancer Institute, The University of Utah, Salt Lake City, Utah
| | - Kevin C Gantz
- Huntsman Cancer Institute, The University of Utah, Salt Lake City, Utah
| | - Hannah M Redwine
- Huntsman Cancer Institute, The University of Utah, Salt Lake City, Utah
| | - Sabina I Swierczek
- Division of Hematology and Hematologic Malignancies, The University of Utah, Salt Lake City, Utah
| | | | | | | | - Jamshid S Khorashad
- Department of Cellular Pathology, Hammersmith Hospital, Imperial College Health Care NHS Trust, London, United Kingdom
| | - Todd W Kelley
- Department of Pathology, The University of Utah, Salt Lake City, Utah
| | - Mohamed E Salama
- Department of Pathology, The University of Utah, Salt Lake City, Utah
| | - Rodney R Miles
- Department of Pathology, The University of Utah, Salt Lake City, Utah
| | - Kenneth M Boucher
- Huntsman Cancer Institute, The University of Utah, Salt Lake City, Utah
| | - Josef T Prchal
- Division of Hematology and Hematologic Malignancies, The University of Utah, Salt Lake City, Utah
| | - Thomas O'Hare
- Huntsman Cancer Institute, The University of Utah, Salt Lake City, Utah.,Division of Hematology and Hematologic Malignancies, The University of Utah, Salt Lake City, Utah
| | - Michael W Deininger
- Huntsman Cancer Institute, The University of Utah, Salt Lake City, Utah. .,Division of Hematology and Hematologic Malignancies, The University of Utah, Salt Lake City, Utah
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20
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Nguyen T, Pappireddi N, Wühr M. Proteomics of nucleocytoplasmic partitioning. Curr Opin Chem Biol 2018; 48:55-63. [PMID: 30472625 DOI: 10.1016/j.cbpa.2018.10.027] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 10/30/2018] [Accepted: 10/31/2018] [Indexed: 12/21/2022]
Abstract
The partitioning of the proteome between nucleus and cytoplasm affects nearly every aspect of eukaryotic biology. Despite this central role, we still have a poor understanding of which proteins localize in the nucleus and how this varies in different cell types and conditions. Recent advances in quantitative proteomics and high-throughput imaging are starting to close this knowledge gap. Studies on protein interaction are beginning to reveal the spectrum of cargos of nuclear import and export receptors. We anticipate that it will soon be possible to predict each protein's nucleocytoplasmic localization based on its importin/exportin interactions and its estimated diffusion rate through the nuclear pore. This insight is likely to provide us with a fundamental understanding of how cells use nucleocytoplasmic partitioning to encode and relay information.
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Affiliation(s)
- Thao Nguyen
- Department of Molecular Biology & the Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Nishant Pappireddi
- Department of Molecular Biology & the Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Martin Wühr
- Department of Molecular Biology & the Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA.
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21
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Fu SC, Fung HYJ, Cağatay T, Baumhardt J, Chook YM. Correlation of CRM1-NES affinity with nuclear export activity. Mol Biol Cell 2018; 29:2037-2044. [PMID: 29927350 PMCID: PMC6232958 DOI: 10.1091/mbc.e18-02-0096] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 06/04/2018] [Accepted: 06/14/2018] [Indexed: 11/21/2022] Open
Abstract
CRM1 (Exportin1/XPO1) exports hundreds of broadly functioning protein cargoes out of the cell nucleus by binding to their classical nuclear export signals (NESs). The 8- to 15-amino-acid-long NESs contain four to five hydrophobic residues and are highly diverse in both sequence and CRM1-bound structure. Here we examine the relationship between nuclear export activities of 24 different NES peptides in cells and their CRM1-NES affinities. We found that binding affinity and nuclear export activity are linearly correlated for NESs with dissociation constants ( Kds) between tens of nanomolar to tens of micromolar. NESs with Kds outside this range have significantly reduced nuclear export activities. These include two unusually tight-binding peptides, one from the nonstructural protein 2 of murine minute virus (MVM NS2) and the other a mutant of the protein kinase A inhibitor (PKI) NES. The crystal structure of CRM1-bound MVM NS2NES suggests that extraordinarily tight CRM1 binding arises from intramolecular contacts within the NES that likely stabilizes the CRM1-bound conformation in free peptides. This mechanistic understanding led to the design of two novel peptide inhibitors that bind CRM1 with picomolar affinity.
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Affiliation(s)
- Szu-Chin Fu
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Ho Yee Joyce Fung
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Tolga Cağatay
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Jordan Baumhardt
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Yuh Min Chook
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390
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22
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Fu X, Liang C, Li F, Wang L, Wu X, Lu A, Xiao G, Zhang G. The Rules and Functions of Nucleocytoplasmic Shuttling Proteins. Int J Mol Sci 2018; 19:ijms19051445. [PMID: 29757215 PMCID: PMC5983729 DOI: 10.3390/ijms19051445] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 04/16/2018] [Accepted: 04/17/2018] [Indexed: 12/14/2022] Open
Abstract
Biological macromolecules are the basis of life activities. There is a separation of spatial dimension between DNA replication and RNA biogenesis, and protein synthesis, which is an interesting phenomenon. The former occurs in the cell nucleus, while the latter in the cytoplasm. The separation requires protein to transport across the nuclear envelope to realize a variety of biological functions. Nucleocytoplasmic transport of protein including import to the nucleus and export to the cytoplasm is a complicated process that requires involvement and interaction of many proteins. In recent years, many studies have found that proteins constantly shuttle between the cytoplasm and the nucleus. These shuttling proteins play a crucial role as transport carriers and signal transduction regulators within cells. In this review, we describe the mechanism of nucleocytoplasmic transport of shuttling proteins and summarize some important diseases related shuttling proteins.
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Affiliation(s)
- Xuekun Fu
- Department of Biology and Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, Southern University of Science and Technology, Shenzhen 518055, China.
- Law Sau Fai Institute for Advancing Translational Medicine in Bone and Joint Diseases, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China.
| | - Chao Liang
- Law Sau Fai Institute for Advancing Translational Medicine in Bone and Joint Diseases, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China.
- Institute of Integrated Bioinfomedicine and Translational Science, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China.
- Institute of Precision Medicine and Innovative Drug Discovery, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China.
- Shenzhen Lab of Combinatorial Compounds and Targeted Drug Delivery, HKBU Institute of Research and Continuing Education, Shenzhen 518057, China.
| | - Fangfei Li
- Law Sau Fai Institute for Advancing Translational Medicine in Bone and Joint Diseases, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China.
- Institute of Integrated Bioinfomedicine and Translational Science, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China.
- Institute of Precision Medicine and Innovative Drug Discovery, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China.
- Shenzhen Lab of Combinatorial Compounds and Targeted Drug Delivery, HKBU Institute of Research and Continuing Education, Shenzhen 518057, China.
| | - Luyao Wang
- Law Sau Fai Institute for Advancing Translational Medicine in Bone and Joint Diseases, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China.
- Institute of Integrated Bioinfomedicine and Translational Science, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China.
- Institute of Precision Medicine and Innovative Drug Discovery, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China.
- Shenzhen Lab of Combinatorial Compounds and Targeted Drug Delivery, HKBU Institute of Research and Continuing Education, Shenzhen 518057, China.
| | - Xiaoqiu Wu
- Law Sau Fai Institute for Advancing Translational Medicine in Bone and Joint Diseases, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China.
- Institute of Integrated Bioinfomedicine and Translational Science, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China.
- Institute of Precision Medicine and Innovative Drug Discovery, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China.
- Shenzhen Lab of Combinatorial Compounds and Targeted Drug Delivery, HKBU Institute of Research and Continuing Education, Shenzhen 518057, China.
| | - Aiping Lu
- Law Sau Fai Institute for Advancing Translational Medicine in Bone and Joint Diseases, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China.
- Institute of Integrated Bioinfomedicine and Translational Science, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China.
- Institute of Precision Medicine and Innovative Drug Discovery, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China.
- Shenzhen Lab of Combinatorial Compounds and Targeted Drug Delivery, HKBU Institute of Research and Continuing Education, Shenzhen 518057, China.
| | - Guozhi Xiao
- Department of Biology and Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, Southern University of Science and Technology, Shenzhen 518055, China.
- Department of Orthopedic Surgery, Rush University Medical Center, Chicago, IL 60612, USA.
| | - Ge Zhang
- Law Sau Fai Institute for Advancing Translational Medicine in Bone and Joint Diseases, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China.
- Institute of Integrated Bioinfomedicine and Translational Science, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China.
- Institute of Precision Medicine and Innovative Drug Discovery, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China.
- Shenzhen Lab of Combinatorial Compounds and Targeted Drug Delivery, HKBU Institute of Research and Continuing Education, Shenzhen 518057, China.
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23
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Pickens JA, Tripp RA. Verdinexor Targeting of CRM1 is a Promising Therapeutic Approach against RSV and Influenza Viruses. Viruses 2018; 10:E48. [PMID: 29361733 PMCID: PMC5795461 DOI: 10.3390/v10010048] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2017] [Revised: 01/15/2018] [Accepted: 01/17/2018] [Indexed: 12/11/2022] Open
Abstract
Two primary causes of respiratory tract infections are respiratory syncytial virus (RSV) and influenza viruses, both of which remain major public health concerns. There are a limited number of antiviral drugs available for the treatment of RSV and influenza, each having limited effectiveness and each driving selective pressure for the emergence of drug-resistant viruses. Novel broad-spectrum antivirals are needed to circumvent problems with current disease intervention strategies, while improving the cytokine-induced immunopathology associated with RSV and influenza infections. In this review, we examine the use of Verdinexor (KPT-335, a novel orally bioavailable drug that functions as a selective inhibitor of nuclear export, SINE), as an antiviral with multifaceted therapeutic potential. KPT-335 works to (1) block CRM1 (i.e., Chromosome Region Maintenance 1; exportin 1 or XPO1) mediated export of viral proteins critical for RSV and influenza pathogenesis; and (2) repress nuclear factor κB (NF-κB) activation, thus reducing cytokine production and eliminating virus-associated immunopathology. The repurposing of SINE compounds as antivirals shows promise not only against RSV and influenza virus but also against other viruses that exploit the nucleus as part of their viral life cycle.
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Affiliation(s)
- Jennifer A Pickens
- Department of Infectious Diseases, University of Georgia, Athens, GA 30602, USA.
| | - Ralph A Tripp
- Department of Infectious Diseases, University of Georgia, Athens, GA 30602, USA.
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24
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Chutiwitoonchai N, Mano T, Kakisaka M, Sato H, Kondoh Y, Osada H, Kotani O, Yokoyama M, Sato H, Aida Y. Inhibition of CRM1-mediated nuclear export of influenza A nucleoprotein and nuclear export protein as a novel target for antiviral drug development. Virology 2017; 507:32-39. [PMID: 28399435 PMCID: PMC7111614 DOI: 10.1016/j.virol.2017.04.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 03/31/2017] [Accepted: 04/03/2017] [Indexed: 12/18/2022]
Abstract
An anti-influenza compound, DP2392-E10 based on inhibition of the nuclear export function of the viral nucleoprotein-nuclear export signal 3 (NP-NES3) domain was successfully identified by our previous high-throughput screening system. Here, we demonstrated that DP2392-E10 exerts its antiviral effect by inhibiting replication of a broad range of influenza A subtypes. In regard to the molecular mechanism, we revealed that DP2392-E10 inhibits nuclear export of both viral NP and nuclear export protein (NEP). More specifically, in vitro pull-down assays revealed that DP2392-E10 directly binds cellular CRM1, which mediates nuclear export of NP and NEP. In silico docking suggested that DP2392-E10 binds at a region close to the HEAT9 and HEAT10 domains of CRM1. Together, these results indicate that the CRM1-mediated nuclear export function of influenza virus represents a new potential target for antiviral drug development, and also provide a core structure for a novel class of inhibitors that target this function.
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Affiliation(s)
| | - Takafumi Mano
- Viral Infectious Disease Unit, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Michinori Kakisaka
- Viral Infectious Disease Unit, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Hirotaka Sato
- Viral Infectious Disease Unit, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Yasumitsu Kondoh
- Chemical Biology Research Group, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Hiroyuki Osada
- Chemical Biology Research Group, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Osamu Kotani
- Laboratory of Viral Genomics, Pathogen Genomics Center, National Institute of Infectious Diseases, 4-7-1 Gakuen, Musashimurayama, Tokyo 208-0011, Japan
| | - Masaru Yokoyama
- Laboratory of Viral Genomics, Pathogen Genomics Center, National Institute of Infectious Diseases, 4-7-1 Gakuen, Musashimurayama, Tokyo 208-0011, Japan
| | - Hironori Sato
- Laboratory of Viral Genomics, Pathogen Genomics Center, National Institute of Infectious Diseases, 4-7-1 Gakuen, Musashimurayama, Tokyo 208-0011, Japan
| | - Yoko Aida
- Viral Infectious Disease Unit, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
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25
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Camus V, Miloudi H, Taly A, Sola B, Jardin F. XPO1 in B cell hematological malignancies: from recurrent somatic mutations to targeted therapy. J Hematol Oncol 2017; 10:47. [PMID: 28196522 PMCID: PMC5307790 DOI: 10.1186/s13045-017-0412-4] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 01/31/2017] [Indexed: 02/07/2023] Open
Abstract
Many recent publications highlight the large role of the pivotal eukaryotic nuclear export protein exportin-1 (XPO1) in the oncogenesis of several malignancies, and there is emerging evidence that XPO1 inhibition is a key target against cancer. The clinical validation of the pharmacological inhibition of XPO1 was recently achieved with the development of the selective inhibitor of nuclear export compounds, displaying an interesting anti-tumor activity in patients with massive pre-treated hematological malignancies. Recent reports have shown molecular alterations in the gene encoding XPO1 and showed a mutation hotspot (E571K) in the following two hematological malignancies with similar phenotypes and natural histories: primary mediastinal diffuse large B cell lymphoma and classical Hodgkin's lymphoma. Emerging evidence suggests that the mutant XPO1 E571K plays a role in carcinogenesis, and this variant is quantifiable in tumor and plasma cell-free DNA of patients using highly sensitive molecular biology techniques, such as digital PCR and next-generation sequencing. Therefore, it was proposed that the XPO1 E571K variant may serve as a minimal residual disease tool in this setting. To clarify and summarize the recent findings on the role of XPO1 in B cell hematological malignancies, we conducted a literature search to present the major publications establishing the landscape of XPO1 molecular alterations, their impact on the XPO1 protein, their interest as biomarkers, and investigations into the development of new XPO1-targeted therapies in B cell hematological malignancies.
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Affiliation(s)
- Vincent Camus
- Normandie Univ, INSERM U1245, UNICAEN, UNIROUEN, Caen, France
- Department of Hematology, Centre Henri Becquerel, Rouen, France
| | - Hadjer Miloudi
- Normandie Univ, INSERM U1245, UNICAEN, UNIROUEN, Caen, France
| | - Antoine Taly
- Laboratoire de Biochimie Théorique, Institut de Biologie Physico-Chimique, CNRS, Université Paris Diderot, Paris, France
| | - Brigitte Sola
- Normandie Univ, INSERM U1245, UNICAEN, UNIROUEN, Caen, France.
| | - Fabrice Jardin
- Normandie Univ, INSERM U1245, UNICAEN, UNIROUEN, Caen, France
- Department of Hematology, Centre Henri Becquerel, Rouen, France
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26
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Grayton JE, Miller T, Wilson-Robles H. In vitro evaluation of Selective Inhibitors of Nuclear Export (SINE) drugs KPT-185 and KPT-335 against canine mammary carcinoma and transitional cell carcinoma tumor initiating cells. Vet Comp Oncol 2017; 15:1455-1467. [PMID: 28133930 DOI: 10.1111/vco.12289] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 10/17/2016] [Accepted: 10/17/2016] [Indexed: 12/21/2022]
Affiliation(s)
- J E Grayton
- Small Animal Clinical Sciences, Texas A&M University College of Veterinary Medicine and Biomedical Sciences, College Station, TX, USA
| | - T Miller
- Small Animal Clinical Sciences, Texas A&M University, College Station, TX, USA
| | - H Wilson-Robles
- Small Animal Clinical Sciences, Texas A&M University, College Station, TX, USA
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27
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Etchin J, Berezovskaya A, Conway AS, Galinsky IA, Stone RM, Baloglu E, Senapedis W, Landesman Y, Kauffman M, Shacham S, Wang JCY, Look AT. KPT-8602, a second-generation inhibitor of XPO1-mediated nuclear export, is well tolerated and highly active against AML blasts and leukemia-initiating cells. Leukemia 2017; 31:143-150. [PMID: 27211268 PMCID: PMC5220128 DOI: 10.1038/leu.2016.145] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Revised: 03/24/2016] [Accepted: 04/25/2016] [Indexed: 12/30/2022]
Abstract
Acute myeloid leukemia (AML) is a clonal hematologic malignant disease of developing myeloid cells that have acquired aberrant survival, uncontrolled proliferation and a block in normal hematopoietic cell differentiation. Standard chemotherapy often induces remissions in AML patients, but the disease frequently relapses due to incomplete targeting of leukemia-initiating cells (LICs), emphasizing the need for novel effective treatments. Exportin 1 (XPO1)-mediated nuclear export, which is inhibited by the drug selinexor, is an attractive new therapeutic target in AML. Selinexor has shown impressive activity in Phase I/II clinical trials for AML. Here we report the anti-leukemic efficacy and tolerability of KPT-8602, a second-generation XPO1 inhibitor. KPT-8602 demonstrates substantially reduced brain penetration compared to selinexor, with resultant attenuation of the central nervous system mediated side effects of anorexia and weight loss. Due to its improved tolerability profile, KPT-8602 can be given daily compared to the two or three times weekly regimen of selinexor, and exhibits greater anti-leukemic efficacy against both leukemic blasts and LICs in AML patient-derived xenograft models. Importantly, normal hematopoietic stem and progenitor cell (HSPC) frequency is not significantly reduced by KPT-8602, providing a therapeutic window for elimination of relapse-driving LICs while sparing normal HSPCs. These findings strongly endorse clinical testing of KPT-8602 in patients with relapsed and refractory AML.
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Affiliation(s)
- J Etchin
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
- Division of Hematology/Oncology, Children's Hospital, Boston, MA, USA
| | - A Berezovskaya
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - A S Conway
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - I A Galinsky
- Department of Medical Oncology, Dana-Farber Cancer Institute, and Harvard Medical School, Boston, MA, USA
| | - R M Stone
- Department of Medical Oncology, Dana-Farber Cancer Institute, and Harvard Medical School, Boston, MA, USA
| | - E Baloglu
- Karyopharm Therapeutics, Newton, MA, USA
| | | | | | - M Kauffman
- Karyopharm Therapeutics, Newton, MA, USA
| | - S Shacham
- Karyopharm Therapeutics, Newton, MA, USA
| | - J C Y Wang
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada
- Department of Medicine, University of Toronto, Toronto, ON, Canada
| | - A T Look
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
- Division of Hematology/Oncology, Children's Hospital, Boston, MA, USA
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28
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García-Santisteban I, Arregi I, Alonso-Mariño M, Urbaneja MA, Garcia-Vallejo JJ, Bañuelos S, Rodríguez JA. A cellular reporter to evaluate CRM1 nuclear export activity: functional analysis of the cancer-related mutant E571K. Cell Mol Life Sci 2016; 73:4685-4699. [PMID: 27312238 PMCID: PMC11108298 DOI: 10.1007/s00018-016-2292-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 05/10/2016] [Accepted: 06/07/2016] [Indexed: 01/02/2023]
Abstract
The exportin CRM1 binds nuclear export signals (NESs), and mediates active transport of NES-bearing proteins from the nucleus to the cytoplasm. Structural and biochemical analyses have uncovered the molecular mechanisms underlying CRM1/NES interaction. CRM1 binds NESs through a hydrophobic cleft, whose open or closed conformation facilitates NES binding and release. Several cofactors allosterically modulate the conformation of the NES-binding cleft through intramolecular interactions involving an acidic loop and a C-terminal helix in CRM1. This current model of CRM1-mediated nuclear export has not yet been evaluated in a cellular setting. Here, we describe SRV100, a cellular reporter to interrogate CRM1 nuclear export activity. Using this novel tool, we provide evidence further validating the model of NES binding and release by CRM1. Furthermore, using both SRV100-based cellular assays and in vitro biochemical analyses, we investigate the functional consequences of a recurrent cancer-related mutation, which targets a residue near CRM1 NES-binding cleft. Our data indicate that this mutation does not necessarily abrogate the nuclear export activity of CRM1, but may increase its affinity for NES sequences bearing a more negatively charged C-terminal end.
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Affiliation(s)
- Iraia García-Santisteban
- Department of Genetics, Physical Anthropology and Animal Physiology, University of the Basque Country (UPV/EHU), Leioa, Spain
- Division of Cell Biology I, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Igor Arregi
- Department of Biochemistry and Molecular Biology, Biofisika Institute (UPV/EHU, CSIC), University of the Basque Country, Leioa, Spain
| | - Marián Alonso-Mariño
- Department of Biochemistry and Molecular Biology, Biofisika Institute (UPV/EHU, CSIC), University of the Basque Country, Leioa, Spain
| | - María A Urbaneja
- Department of Biochemistry and Molecular Biology, Biofisika Institute (UPV/EHU, CSIC), University of the Basque Country, Leioa, Spain
| | - Juan J Garcia-Vallejo
- Department of Molecular Cell Biology and Immunology, VU University Medical Center, Amsterdam, The Netherlands
| | - Sonia Bañuelos
- Department of Biochemistry and Molecular Biology, Biofisika Institute (UPV/EHU, CSIC), University of the Basque Country, Leioa, Spain.
| | - Jose A Rodríguez
- Department of Genetics, Physical Anthropology and Animal Physiology, University of the Basque Country (UPV/EHU), Leioa, Spain.
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29
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A computational approach for nuclear export signals identification using spiking neural P systems. Neural Comput Appl 2016. [DOI: 10.1007/s00521-016-2489-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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30
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Sun Q, Chen X, Zhou Q, Burstein E, Yang S, Jia D. Inhibiting cancer cell hallmark features through nuclear export inhibition. Signal Transduct Target Ther 2016; 1:16010. [PMID: 29263896 PMCID: PMC5661660 DOI: 10.1038/sigtrans.2016.10] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 04/28/2016] [Accepted: 05/31/2016] [Indexed: 02/05/2023] Open
Abstract
Treating cancer through inhibition of nuclear export is one of the best examples of basic research translation into clinical application. Nuclear export factor chromosomal region maintenance 1 (CRM1; Xpo1 and exportin-1) controls cellular localization and function of numerous proteins that are critical for the development of many cancer hallmarks. The diverse actions of CRM1 are likely to explain the broad ranging anti-cancer potency of CRM1 inhibitors observed in pre-clinical studies and/or clinical trials (phase I–III) on both advanced-stage solid and hematological tumors. In this review, we compare and contrast the mechanisms of action of different CRM1 inhibitors, and discuss the potential benefit of unexplored non-covalent CRM1 inhibitors. This emerging field has uncovered that nuclear export inhibition is well poised as an attractive target towards low-toxicity broad-spectrum potent anti-cancer therapy.
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Affiliation(s)
- Qingxiang Sun
- State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu, China.,Department of Pathology, West China Hospital, Sichuan University, Chengdu, China
| | - Xueqin Chen
- Department of Pathology, West China Hospital, Sichuan University, Chengdu, China
| | - Qiao Zhou
- Department of Pathology, West China Hospital, Sichuan University, Chengdu, China
| | - Ezra Burstein
- Department of Internal Medicine, UT Southwestern Medical Center, Dallas, Texas, USA.,Department of Molecular Biology, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Shengyong Yang
- State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu, China
| | - Da Jia
- State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu, China.,West China 2nd University Hospital, Sichuan University, Chengdu, China
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31
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Fernandes JD, Booth DS, Frankel AD. A structurally plastic ribonucleoprotein complex mediates post-transcriptional gene regulation in HIV-1. WILEY INTERDISCIPLINARY REVIEWS-RNA 2016; 7:470-86. [PMID: 26929078 DOI: 10.1002/wrna.1342] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 01/12/2016] [Accepted: 01/14/2016] [Indexed: 01/28/2023]
Abstract
HIV replication requires the nuclear export of essential, intron-containing viral RNAs. To facilitate export, HIV encodes the viral accessory protein Rev which binds unspliced and partially spliced viral RNAs and creates a ribonucleoprotein complex that recruits the cellular Chromosome maintenance factor 1 export machinery. Exporting RNAs in this manner bypasses the necessity for complete splicing as a prerequisite for mRNA export, and allows intron-containing RNAs to reach the cytoplasm intact for translation and virus packaging. Recent structural studies have revealed that this entire complex exhibits remarkable plasticity at many levels of organization, including RNA folding, protein-RNA recognition, multimer formation, and host factor recruitment. In this review, we explore each aspect of plasticity from structural, functional, and possible therapeutic viewpoints. WIREs RNA 2016, 7:470-486. doi: 10.1002/wrna.1342 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Jason D Fernandes
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA, USA
| | - David S Booth
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | - Alan D Frankel
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA, USA
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32
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Crane EA, Gademann K. Synthetisch gewonnene Naturstofffragmente in der Wirkstoffentwicklung. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201505863] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Erika A. Crane
- Departement Chemie; Universität Basel; St. Johanns-Ring 19 CH-4056 Basel Schweiz
| | - Karl Gademann
- Departement Chemie; Universität Basel; St. Johanns-Ring 19 CH-4056 Basel Schweiz
- Institut für Chemie; Universität Zürich; Winterthurerstrasse 190 CH-8057 Zürich Schweiz
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33
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Crane EA, Gademann K. Capturing Biological Activity in Natural Product Fragments by Chemical Synthesis. Angew Chem Int Ed Engl 2016; 55:3882-902. [PMID: 26833854 PMCID: PMC4797711 DOI: 10.1002/anie.201505863] [Citation(s) in RCA: 106] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Indexed: 12/22/2022]
Abstract
Natural products have had an immense influence on science and have directly led to the introduction of many drugs. Organic chemistry, and its unique ability to tailor natural products through synthesis, provides an extraordinary approach to unlock the full potential of natural products. In this Review, an approach based on natural product derived fragments is presented that can successfully address some of the current challenges in drug discovery. These fragments often display significantly reduced molecular weights, reduced structural complexity, a reduced number of synthetic steps, while retaining or even improving key biological parameters such as potency or selectivity. Examples from various stages of the drug development process up to the clinic are presented. In addition, this process can be leveraged by recent developments such as genome mining, antibody–drug conjugates, and computational approaches. All these concepts have the potential to identify the next generation of drug candidates inspired by natural products.
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Affiliation(s)
- Erika A Crane
- Department of Chemistry, University of Basel, Switzerland
| | - Karl Gademann
- Department of Chemistry, University of Basel, Switzerland. .,Department of Chemistry, University of Zürich, Winterthurerstrasse 190, CH-8057, Zürich, Switzerland.
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34
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Etchin J, Montero J, Berezovskaya A, Le BT, Kentsis A, Christie AL, Conway AS, Chen WC, Reed C, Mansour MR, Ng CEL, Adamia S, Rodig SJ, Galinsky IA, Stone RM, Klebanov B, Landesman Y, Kauffman M, Shacham S, Kung AL, Wang JCY, Letai A, Look AT. Activity of a selective inhibitor of nuclear export, selinexor (KPT-330), against AML-initiating cells engrafted into immunosuppressed NSG mice. Leukemia 2016; 30:190-9. [PMID: 26202935 PMCID: PMC4994896 DOI: 10.1038/leu.2015.194] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 05/28/2015] [Accepted: 06/29/2015] [Indexed: 01/08/2023]
Abstract
Currently available combination chemotherapy for acute myeloid leukemia (AML) often fails to result in long-term remissions, emphasizing the need for novel therapeutic strategies. We reasoned that targeted inhibition of a prominent nuclear exporter, XPO1/CRM1, could eradicate self-renewing leukemia-initiating cells (LICs) whose survival depends on timely XPO1-mediated transport of specific protein and RNA cargoes. Using an immunosuppressed mouse model bearing primary patient-derived AML cells, we demonstrate that selinexor (KPT-330), an oral antagonist of XPO1 that is currently in clinical trials, has strong activity against primary AML cells while sparing normal stem and progenitor cells. Importantly, limiting dilution transplantation assays showed that this cytotoxic activity is not limited to the rapidly proliferating bulk population of leukemic cells but extends to the LICs, whose inherent drug resistance and unrestricted self-renewal capacity has been implicated in the difficulty of curing AML patients with conventional chemotherapy alone.
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Affiliation(s)
- J Etchin
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, and Division of Hematology/Oncology, Children’s Hospital Boston, Harvard Medical School, Boston, MA, USA
- Division of Hematology/Oncology, Children's Hospital, Boston, MA, USA
| | - J Montero
- Department of Medical Oncology, Dana-Farber Cancer Institute, and Harvard Medical School, Boston, MA, USA
| | - A Berezovskaya
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, and Division of Hematology/Oncology, Children’s Hospital Boston, Harvard Medical School, Boston, MA, USA
| | - BT Le
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, and Division of Hematology/Oncology, Children’s Hospital Boston, Harvard Medical School, Boston, MA, USA
| | - A Kentsis
- Memorial Sloan-Kettering Cancer Center, New York, NY, USA
| | - AL Christie
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, and Division of Hematology/Oncology, Children’s Hospital Boston, Harvard Medical School, Boston, MA, USA
| | - AS Conway
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, and Division of Hematology/Oncology, Children’s Hospital Boston, Harvard Medical School, Boston, MA, USA
| | - WC Chen
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
- Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - C Reed
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, and Division of Hematology/Oncology, Children’s Hospital Boston, Harvard Medical School, Boston, MA, USA
| | - MR Mansour
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, and Division of Hematology/Oncology, Children’s Hospital Boston, Harvard Medical School, Boston, MA, USA
- Department of Haematology, UCL Cancer Institute, University College London, London, UK
| | - CEL Ng
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, and Division of Hematology/Oncology, Children’s Hospital Boston, Harvard Medical School, Boston, MA, USA
| | - S Adamia
- Department of Medical Oncology, Dana-Farber Cancer Institute, and Harvard Medical School, Boston, MA, USA
| | - SJ Rodig
- Department of Pathology, Brigham and Women’s Hospital, Boston, MA, USA
| | - IA Galinsky
- Department of Medical Oncology, Dana-Farber Cancer Institute, and Harvard Medical School, Boston, MA, USA
| | - RM Stone
- Department of Medical Oncology, Dana-Farber Cancer Institute, and Harvard Medical School, Boston, MA, USA
| | - B Klebanov
- Karyopharm Therapeutics, Natick, MA, USA
| | | | - M Kauffman
- Karyopharm Therapeutics, Natick, MA, USA
| | - S Shacham
- Karyopharm Therapeutics, Natick, MA, USA
| | - AL Kung
- Division of Pediatric Hematology/Oncology/Stem Cell Transplantation, Columbia University Medical Center, New York, NY, USA
| | - JCY Wang
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
- Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - A Letai
- Department of Medical Oncology, Dana-Farber Cancer Institute, and Harvard Medical School, Boston, MA, USA
| | - AT Look
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, and Division of Hematology/Oncology, Children’s Hospital Boston, Harvard Medical School, Boston, MA, USA
- Division of Hematology/Oncology, Children's Hospital, Boston, MA, USA
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35
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Port SA, Monecke T, Dickmanns A, Spillner C, Hofele R, Urlaub H, Ficner R, Kehlenbach RH. Structural and Functional Characterization of CRM1-Nup214 Interactions Reveals Multiple FG-Binding Sites Involved in Nuclear Export. Cell Rep 2015; 13:690-702. [PMID: 26489467 DOI: 10.1016/j.celrep.2015.09.042] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 08/11/2015] [Accepted: 09/14/2015] [Indexed: 12/11/2022] Open
Abstract
CRM1 is the major nuclear export receptor. During translocation through the nuclear pore, transport complexes transiently interact with phenylalanine-glycine (FG) repeats of multiple nucleoporins. On the cytoplasmic side of the nuclear pore, CRM1 tightly interacts with the nucleoporin Nup214. Here, we present the crystal structure of a 117-amino-acid FG-repeat-containing fragment of Nup214, in complex with CRM1, Snurportin 1, and RanGTP at 2.85 Å resolution. The structure reveals eight binding sites for Nup214 FG motifs on CRM1, with intervening stretches that are loosely attached to the transport receptor. Nup214 binds to N- and C-terminal regions of CRM1, thereby clamping CRM1 in a closed conformation and stabilizing the export complex. The role of conserved hydrophobic pockets for the recognition of FG motifs was analyzed in biochemical and cell-based assays. Comparative studies with RanBP3 and Nup62 shed light on specificities of CRM1-nucleoporin binding, which serves as a paradigm for transport receptor-nucleoporin interactions.
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Affiliation(s)
- Sarah A Port
- Department of Molecular Biology, Faculty of Medicine, GZMB, Georg-August-University Göttingen, Humboldtallee 23, 37073 Göttingen, Germany
| | - Thomas Monecke
- Department of Molecular Structural Biology, Institute for Microbiology and Genetics, GZMB, Georg-August-University Göttingen, Justus-von-Liebig-Weg 11, 37077 Göttingen, Germany
| | - Achim Dickmanns
- Department of Molecular Structural Biology, Institute for Microbiology and Genetics, GZMB, Georg-August-University Göttingen, Justus-von-Liebig-Weg 11, 37077 Göttingen, Germany
| | - Christiane Spillner
- Department of Molecular Biology, Faculty of Medicine, GZMB, Georg-August-University Göttingen, Humboldtallee 23, 37073 Göttingen, Germany
| | - Romina Hofele
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany; Bioanalytics, Institute for Clinical Chemistry, University Medical Center, Robert-Koch-Str. 40, 37075 Göttingen, Germany
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany; Bioanalytics, Institute for Clinical Chemistry, University Medical Center, Robert-Koch-Str. 40, 37075 Göttingen, Germany
| | - Ralf Ficner
- Department of Molecular Structural Biology, Institute for Microbiology and Genetics, GZMB, Georg-August-University Göttingen, Justus-von-Liebig-Weg 11, 37077 Göttingen, Germany.
| | - Ralph H Kehlenbach
- Department of Molecular Biology, Faculty of Medicine, GZMB, Georg-August-University Göttingen, Humboldtallee 23, 37073 Göttingen, Germany.
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Ishizawa J, Kojima K, Hail N, Tabe Y, Andreeff M. Expression, function, and targeting of the nuclear exporter chromosome region maintenance 1 (CRM1) protein. Pharmacol Ther 2015; 153:25-35. [PMID: 26048327 PMCID: PMC4526315 DOI: 10.1016/j.pharmthera.2015.06.001] [Citation(s) in RCA: 97] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 05/07/2015] [Indexed: 12/11/2022]
Abstract
Nucleocytoplasmic trafficking of proteins/RNAs is essential to normal cellular function. Indeed, accumulating evidence suggests that cancer cells escape anti-neoplastic mechanisms and benefit from pro-survival signals via the dysregulation of this system. The nuclear exporter chromosome region maintenance 1 (CRM1) protein is the only protein in the karyopherin-β protein family that contributes to the trafficking of numerous proteins and RNAs from the nucleus. It is considered to be an oncogenic, anti-apoptotic protein in transformed cells, since it reportedly functions as a gatekeeper for cell survival, including affecting p53 function, and ribosomal biogenesis. Furthermore, abnormally high expression of CRM1 is correlated with poor patient prognosis in various malignancies. Therapeutic targeting of CRM1 has emerged as a novel cancer treatment strategy, starting with a clinical trial with leptomycin B, the original specific inhibitor of CRM1, followed by development of several next-generation small molecules. KPT-330, a novel member of the CRM1-selective inhibitors of nuclear export (SINE) class of compounds, is currently undergoing clinical evaluation for the therapy of various malignancies. Results from these trials suggest that SINE compounds may be particularly useful against hematological malignancies, which often become refractory to standard chemotherapeutic agents.
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Affiliation(s)
- Jo Ishizawa
- Section of Molecular Hematology and Therapy, Department of Leukemia, the University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Kensuke Kojima
- Section of Molecular Hematology and Therapy, Department of Leukemia, the University of Texas MD Anderson Cancer Center, Houston, TX, USA; Hematology, Respiratory Medicine and Oncology, Department of Medicine, Saga University, Saga, Japan
| | - Numsen Hail
- Section of Molecular Hematology and Therapy, Department of Leukemia, the University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Yoko Tabe
- Department of Clinical Laboratory Medicine, Juntendo University School of Medicine, Tokyo, Japan
| | - Michael Andreeff
- Section of Molecular Hematology and Therapy, Department of Leukemia, the University of Texas MD Anderson Cancer Center, Houston, TX, USA.
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Gallmetzer A, Silvestrini L, Schinko T, Gesslbauer B, Hortschansky P, Dattenböck C, Muro-Pastor MI, Kungl A, Brakhage AA, Scazzocchio C, Strauss J. Reversible Oxidation of a Conserved Methionine in the Nuclear Export Sequence Determines Subcellular Distribution and Activity of the Fungal Nitrate Regulator NirA. PLoS Genet 2015; 11:e1005297. [PMID: 26132230 PMCID: PMC4488483 DOI: 10.1371/journal.pgen.1005297] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Accepted: 05/25/2015] [Indexed: 01/02/2023] Open
Abstract
The assimilation of nitrate, a most important soil nitrogen source, is tightly regulated in microorganisms and plants. In Aspergillus nidulans, during the transcriptional activation process of nitrate assimilatory genes, the interaction between the pathway-specific transcription factor NirA and the exportin KapK/CRM1 is disrupted, and this leads to rapid nuclear accumulation and transcriptional activity of NirA. In this work by mass spectrometry, we found that in the absence of nitrate, when NirA is inactive and predominantly cytosolic, methionine 169 in the nuclear export sequence (NES) is oxidized to methionine sulfoxide (Metox169). This oxidation depends on FmoB, a flavin-containing monooxygenase which in vitro uses methionine and cysteine, but not glutathione, as oxidation substrates. The function of FmoB cannot be replaced by alternative Fmo proteins present in A. nidulans. Exposure of A. nidulans cells to nitrate led to rapid reduction of NirA-Metox169 to Met169; this reduction being independent from thioredoxin and classical methionine sulfoxide reductases. Replacement of Met169 by isoleucine, a sterically similar but not oxidizable residue, led to partial loss of NirA activity and insensitivity to FmoB-mediated nuclear export. In contrast, replacement of Met169 by alanine transformed the protein into a permanently nuclear and active transcription factor. Co-immunoprecipitation analysis of NirA-KapK interactions and subcellular localization studies of NirA mutants lacking different parts of the protein provided evidence that Met169 oxidation leads to a change in NirA conformation. Based on these results we propose that in the presence of nitrate the activation domain is exposed, but the NES is masked by a central portion of the protein (termed nitrate responsive domain, NiRD), thus restricting active NirA molecules to the nucleus. In the absence of nitrate, Met169 in the NES is oxidized by an FmoB-dependent process leading to loss of protection by the NiRD, NES exposure, and relocation of the inactive NirA to the cytosol.
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Affiliation(s)
- Andreas Gallmetzer
- Fungal Genetics and Genomics Unit, Department of Applied Genetics and Cell Biology, BOKU—University of Natural Resources and Life Science, Vienna, Vienna, Austria
| | - Lucia Silvestrini
- Fungal Genetics and Genomics Unit, Department of Applied Genetics and Cell Biology, BOKU—University of Natural Resources and Life Science, Vienna, Vienna, Austria
| | - Thorsten Schinko
- Fungal Genetics and Genomics Unit, Department of Applied Genetics and Cell Biology, BOKU—University of Natural Resources and Life Science, Vienna, Vienna, Austria
| | - Bernd Gesslbauer
- Institute of Pharmaceutical Sciences, Karl-Franzens-University Graz, Graz, Austria
| | - Peter Hortschansky
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoll Institute, Jena, Germany
- Department of Microbiology and Molecular Biology, Friedrich Schiller University Jena, Jena, Germany
| | - Christoph Dattenböck
- Fungal Genetics and Genomics Unit, Department of Applied Genetics and Cell Biology, BOKU—University of Natural Resources and Life Science, Vienna, Vienna, Austria
- Health and Environment Department, Austrian Institute of Technology GmbH—AIT, University and Research Center Tulln, Tulln an der Donau, Austria
| | | | - Andreas Kungl
- Institute of Pharmaceutical Sciences, Karl-Franzens-University Graz, Graz, Austria
| | - Axel A. Brakhage
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoll Institute, Jena, Germany
- Department of Microbiology and Molecular Biology, Friedrich Schiller University Jena, Jena, Germany
| | - Claudio Scazzocchio
- Department of Microbiology, Imperial College, London, United Kingdom, and Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Orsay, France
| | - Joseph Strauss
- Fungal Genetics and Genomics Unit, Department of Applied Genetics and Cell Biology, BOKU—University of Natural Resources and Life Science, Vienna, Vienna, Austria
- Health and Environment Department, Austrian Institute of Technology GmbH—AIT, University and Research Center Tulln, Tulln an der Donau, Austria
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Hauk G, Bowman GD. Formation of a Trimeric Xpo1-Ran[GTP]-Ded1 Exportin Complex Modulates ATPase and Helicase Activities of Ded1. PLoS One 2015; 10:e0131690. [PMID: 26120835 PMCID: PMC4484809 DOI: 10.1371/journal.pone.0131690] [Citation(s) in RCA: 9] [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: 03/23/2015] [Accepted: 06/05/2015] [Indexed: 11/24/2022] Open
Abstract
The DEAD-box RNA helicase Ded1, which is essential in yeast and known as DDX3 in humans, shuttles between the nucleus and cytoplasm and takes part in several basic processes including RNA processing and translation. A key interacting partner of Ded1 is the exportin Xpo1, which together with the GTP-bound state of the small GTPase Ran, facilitates unidirectional transport of Ded1 out of the nucleus. Here we demonstrate that Xpo1 and Ran[GTP] together reduce the RNA-stimulated ATPase and helicase activities of Ded1. Binding and inhibition of Ded1 by Xpo1 depend on the affinity of the Ded1 nuclear export sequence (NES) for Xpo1 and the presence of Ran[GTP]. Association with Xpo1/Ran[GTP] reduces RNA-stimulated ATPase activity of Ded1 by increasing the apparent KM for the RNA substrate. Despite the increased KM, the Ded1:Xpo1:Ran[GTP] ternary complex retains the ability to bind single stranded RNA, suggesting that Xpo1/Ran[GTP] may modulate the substrate specificity of Ded1. These results demonstrate that, in addition to transport, exportins such as Xpo1 also have the capability to alter enzymatic activities of their cargo.
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Affiliation(s)
- Glenn Hauk
- T.C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Gregory D. Bowman
- T.C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, Maryland, United States of America
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Fischer U, Schäuble N, Schütz S, Altvater M, Chang Y, Boulos Faza M, Panse VG. A non-canonical mechanism for Crm1-export cargo complex assembly. eLife 2015; 4:e05745. [PMID: 25895666 PMCID: PMC4402694 DOI: 10.7554/elife.05745] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 03/26/2015] [Indexed: 01/19/2023] Open
Abstract
The transport receptor Crm1 mediates the export of diverse cargos containing leucine-rich nuclear export signals (NESs) through complex formation with RanGTP. To ensure efficient cargo release in the cytoplasm, NESs have evolved to display low affinity for Crm1. However, mechanisms that overcome low affinity to assemble Crm1-export complexes in the nucleus remain poorly understood. In this study, we reveal a new type of RanGTP-binding protein, Slx9, which facilitates Crm1 recruitment to the 40S pre-ribosome-associated NES-containing adaptor Rio2. In vitro, Slx9 binds Rio2 and RanGTP, forming a complex. This complex directly loads Crm1, unveiling a non-canonical stepwise mechanism to assemble a Crm1-export complex. A mutation in Slx9 that impairs Crm1-export complex assembly inhibits 40S pre-ribosome export. Thus, Slx9 functions as a scaffold to optimally present RanGTP and the NES to Crm1, therefore, triggering 40S pre-ribosome export. This mechanism could represent one solution to the paradox of weak binding events underlying rapid Crm1-mediated export.
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Affiliation(s)
- Ute Fischer
- Institute of Biochemistry, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Nico Schäuble
- Institute of Biochemistry, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Sabina Schütz
- Institute of Biochemistry, Department of Biology, ETH Zurich, Zurich, Switzerland
- Molecular Life Science, Graduate School, Zurich, Switzerland
| | - Martin Altvater
- Institute of Biochemistry, Department of Biology, ETH Zurich, Zurich, Switzerland
- Molecular Life Science, Graduate School, Zurich, Switzerland
| | - Yiming Chang
- Institute of Biochemistry, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Marius Boulos Faza
- Institute of Biochemistry, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Vikram Govind Panse
- Institute of Biochemistry, Department of Biology, ETH Zurich, Zurich, Switzerland
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40
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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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41
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Kosugi S, Yanagawa H, Terauchi R, Tabata S. NESmapper: accurate prediction of leucine-rich nuclear export signals using activity-based profiles. PLoS Comput Biol 2014; 10:e1003841. [PMID: 25233087 PMCID: PMC4168985 DOI: 10.1371/journal.pcbi.1003841] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Accepted: 08/02/2014] [Indexed: 11/24/2022] Open
Abstract
The nuclear export of proteins is regulated largely through the exportin/CRM1 pathway, which involves the specific recognition of leucine-rich nuclear export signals (NESs) in the cargo proteins, and modulates nuclear–cytoplasmic protein shuttling by antagonizing the nuclear import activity mediated by importins and the nuclear import signal (NLS). Although the prediction of NESs can help to define proteins that undergo regulated nuclear export, current methods of predicting NESs, including computational tools and consensus-sequence-based searches, have limited accuracy, especially in terms of their specificity. We found that each residue within an NES largely contributes independently and additively to the entire nuclear export activity. We created activity-based profiles of all classes of NESs with a comprehensive mutational analysis in mammalian cells. The profiles highlight a number of specific activity-affecting residues not only at the conserved hydrophobic positions but also in the linker and flanking regions. We then developed a computational tool, NESmapper, to predict NESs by using profiles that had been further optimized by training and combining the amino acid properties of the NES-flanking regions. This tool successfully reduced the considerable number of false positives, and the overall prediction accuracy was higher than that of other methods, including NESsential and Wregex. This profile-based prediction strategy is a reliable way to identify functional protein motifs. NESmapper is available at http://sourceforge.net/projects/nesmapper.
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Affiliation(s)
- Shunichi Kosugi
- Kazusa DNA Research Institute, Kisarazu, Chiba, Japan
- * E-mail:
| | - Hiroshi Yanagawa
- Department of Biosciences and Informatics, Faculty of Science and Technology, Keio University, Yokohama, Japan
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Turner JG, Dawson J, Cubitt CL, Baz R, Sullivan DM. Inhibition of CRM1-dependent nuclear export sensitizes malignant cells to cytotoxic and targeted agents. Semin Cancer Biol 2014; 27:62-73. [PMID: 24631834 PMCID: PMC4108511 DOI: 10.1016/j.semcancer.2014.03.001] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Revised: 02/25/2014] [Accepted: 03/01/2014] [Indexed: 10/25/2022]
Abstract
Nuclear-cytoplasmic trafficking of proteins is a significant factor in the development of cancer and drug resistance. Subcellular localization of exported proteins linked to cancer development include those involved in cell growth and proliferation, apoptosis, cell cycle regulation, transformation, angiogenesis, cell adhesion, invasion, and metastasis. Here, we examined the basic mechanisms involved in the export of proteins from the nucleus to the cytoplasm. All proteins over 40kDa use the nuclear pore complex to gain entry or exit from the nucleus, with the primary nuclear export molecule involved in these processes being chromosome region maintenance 1 (CRM1, exportin 1 or XPO1). Proteins exported from the nucleus must possess a hydrophobic nuclear export signal (NES) peptide that binds to a hydrophobic groove containing an active-site Cys528 in the CRM1 protein. CRM1 inhibitors function largely by covalent modification of the active site Cys528 and prevent binding to the cargo protein NES. In the absence of a CRM1 inhibitor, CRM1 binds cooperatively to the NES of the cargo protein and RanGTP, forming a trimer that is actively transported out of the nucleus by facilitated diffusion. Nuclear export can be blocked by CRM1 inhibitors, NES peptide inhibitors or by preventing post-translational modification of cargo proteins. Clinical trials using the classic CRM1 inhibitor leptomycin B proved too toxic for patients; however, a new generation of less toxic small molecule inhibitors is being used in clinical trials in patients with both hematological malignancies and solid tumors. Additional trials are being initiated using small-molecule CRM1 inhibitors in combination with chemotherapeutics such as pegylated liposomal doxorubicin. In this review, we present evidence that combining the new CRM1 inhibitors with other classes of therapeutics may prove effective in the treatment of cancer. Potential combinatorial therapies discussed include the use of CRM1 inhibitors and the addition of alkylating agents (melphalan), anthracyclines (doxorubicin and daunomycin), BRAF inhibitors, platinum drugs (cisplatin and oxaliplatin), proteosome inhibitors (bortezomib and carfilzomib), or tyrosine-kinase inhibitors (imatinib). Also, the sequence of treatment may be important for combination therapy. We found that the most effective treatment regimen involved first priming the cancer cells with the CRM1 inhibitor followed by doxorubicin, bortezomib, carfilzomib, or melphalan. This order sensitized both de novo and acquired drug-resistant cancer cell lines.
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Affiliation(s)
- Joel G Turner
- Department of Blood and Marrow Transplantation and Chemical Biology and Molecular Medicine Program, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL 33612, USA
| | - Jana Dawson
- Department of Blood and Marrow Transplantation and Chemical Biology and Molecular Medicine Program, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL 33612, USA
| | - Christopher L Cubitt
- Translational Research Core Laboratory, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL 33612, USA
| | - Rachid Baz
- Department of Malignant Hematology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL 33612, USA
| | - Daniel M Sullivan
- Department of Blood and Marrow Transplantation and Chemical Biology and Molecular Medicine Program, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL 33612, USA.
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43
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Fung HYJ, Chook YM. Atomic basis of CRM1-cargo recognition, release and inhibition. Semin Cancer Biol 2014; 27:52-61. [PMID: 24631835 PMCID: PMC4108548 DOI: 10.1016/j.semcancer.2014.03.002] [Citation(s) in RCA: 106] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Accepted: 03/01/2014] [Indexed: 11/19/2022]
Abstract
CRM1 or XPO1 is the major nuclear export receptor in the cell, which controls the nuclear-cytoplasmic localization of many proteins and RNAs. CRM1 is also a promising cancer drug target as the transport receptor is overexpressed in many cancers where some of its cargos are misregulated and mislocalized to the cytoplasm. Atomic level understanding of CRM1 function has greatly facilitated recent drug discovery and development of CRM1 inhibitors to target a variety of malignancies. Numerous atomic resolution CRM1 structures are now available, explaining how the exporter recognizes nuclear export signals in its cargos, how RanGTP and cargo bind with positive cooperativity, how RanBP1 causes release of export cargos in the cytoplasm and how diverse inhibitors such as Leptomycin B and the new KPT-SINE compounds block nuclear export. This review summarizes structure-function studies that explain CRM1-cargo recognition, release and inhibition.
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Affiliation(s)
- Ho Yee Joyce Fung
- Department of Pharmacology, University of Texas Southwestern Medical Center at Dallas, 6001 Forest Park, Dallas, TX 75390-9041, USA.
| | - Yuh Min Chook
- Department of Pharmacology, University of Texas Southwestern Medical Center at Dallas, 6001 Forest Park, Dallas, TX 75390-9041, USA.
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44
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Senapedis WT, Baloglu E, Landesman Y. Clinical translation of nuclear export inhibitors in cancer. Semin Cancer Biol 2014; 27:74-86. [DOI: 10.1016/j.semcancer.2014.04.005] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Accepted: 04/10/2014] [Indexed: 01/18/2023]
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Fleta-Soriano E, Martinez JP, Hinkelmann B, Gerth K, Washausen P, Diez J, Frank R, Sasse F, Meyerhans A. The myxobacterial metabolite ratjadone A inhibits HIV infection by blocking the Rev/CRM1-mediated nuclear export pathway. Microb Cell Fact 2014; 13:17. [PMID: 24475978 PMCID: PMC3910686 DOI: 10.1186/1475-2859-13-17] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Accepted: 01/24/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The nuclear export of unspliced and partially spliced HIV-1 mRNA is mediated by the recognition of a leucine-rich nuclear export signal (NES) in the HIV Rev protein by the host protein CRM1/Exportin1. This makes the CRM1-Rev complex an attractive target for the development of new antiviral drugs. Here we tested the anti-HIV efficacy of ratjadone A, a CRM1 inhibitor derived from myxobacteria. RESULTS Ratjadone A inhibits HIV infection in vitro in a dose-dependent manner with EC₅₀ values at the nanomolar range. The inhibitory effect of ratjadone A occurs around 12 hours post-infection and is specific for the Rev/CRM1-mediated nuclear export pathway. By using a drug affinity responsive target stability (DARTS) assay we could demonstrate that ratjadone A interferes with the formation of the CRM1-Rev-NES complex by binding to CRM1 but not to Rev. CONCLUSION Ratjadone A exhibits strong anti-HIV activity but low selectivity due to toxic effects. Although this limits its potential use as a therapeutic drug, further studies with derivatives of ratjadones might help to overcome these difficulties in the future.
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Affiliation(s)
- Eric Fleta-Soriano
- Infection Biology Group, Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Dr. Aiguader 88 08003, Barcelona, Spain
| | - Javier P Martinez
- Infection Biology Group, Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Dr. Aiguader 88 08003, Barcelona, Spain
| | - Bettina Hinkelmann
- Department of Chemical Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Klaus Gerth
- Department of Microbial Drugs, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Peter Washausen
- Department of Chemical Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Juana Diez
- Molecular Virology Group, Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona, Spain
| | - Ronald Frank
- Department of Chemical Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Florenz Sasse
- Department of Chemical Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Andreas Meyerhans
- Infection Biology Group, Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Dr. Aiguader 88 08003, Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
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46
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Niu M, Wu S, Mao L, Yang Y. CRM1 is a cellular target of curcumin: new insights for the myriad of biological effects of an ancient spice. Traffic 2013; 14:1042-52. [PMID: 23829533 DOI: 10.1111/tra.12090] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Revised: 07/03/2013] [Accepted: 07/06/2013] [Indexed: 12/27/2022]
Abstract
Curcumin is the major constituent of turmeric plant, an ancient spice widely used in Indian cuisine and traditional herbal medicine. Recently, the potential medical use of curcumin as anti-cancer and anti-inflammatory agent has set off an upsurge in research into the mechanism for its broad biological effects. We showed that CRM1, an important nuclear exportin, is a cellular target of curcumin by serious experimental and theoretical investigation. Using a nuclear export functional assay, we observed a clear and rapid shift of cargo proteins from a cytoplasmic localization to the nucleus when treated with curcumin or its structural analogue dibenzylideneacetone (DBA). We demonstrated that curcumin could specifically target the conserved Cys(528) of CRM1 through mass spectrometric analysis and in vivo experiments. Furthermore, computational modeling has revealed that curcumin could be correctly docked into the hydrophobic pocket of CRM1 judged from shape complementarity and putative molecular interactions. The Michael acceptor moiety on curcumin is within the appropriate distance to enable Michael reaction with Cys residue of CRM1. More importantly, we showed that nuclear retention of FOXO1 could be observed in the presence of Leptomycin B (LMB) or curcumin whereas in cells expressing the CRM1-Cys(528) mutant, only a cytoplasmic localization was observed. The inhibition of nuclear traffic by curcumin may account for its myriad of biological effects, particularly for its therapeutic properties in cancer and inflammatory diseases. Our findings may have important implications for further clinical investigation of curcumin.
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Affiliation(s)
- Mingshan Niu
- School of Life Science and Biotechnology, Dalian University of Technology, Dalian, 116024, P.R. China
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47
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Dölker N, Blanchet CE, Voß B, Haselbach D, Kappel C, Monecke T, Svergun DI, Stark H, Ficner R, Zachariae U, Grubmüller H, Dickmanns A. Structural determinants and mechanism of mammalian CRM1 allostery. Structure 2013; 21:1350-60. [PMID: 23850451 DOI: 10.1016/j.str.2013.05.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2013] [Revised: 05/07/2013] [Accepted: 05/26/2013] [Indexed: 10/26/2022]
Abstract
Proteins carrying nuclear export signals cooperatively assemble with the export factor CRM1 and the effector protein RanGTP. In lower eukaryotes, this cooperativity is coupled to CRM1 conformational changes; however, it is unknown if mammalian CRM1 maintains its compact conformation or shows similar structural flexibility. Here, combinations of small-angle X-ray solution scattering and electron microscopy experiments with molecular dynamics simulations reveal pronounced conformational flexibility in mammalian CRM1 and demonstrate that RanGTP binding induces association of its N- and C-terminal regions to form a toroid structure. The CRM1 toroid is stabilized mainly by local interactions between the terminal regions, rather than by global strain. The CRM1 acidic loop is key in transmitting the effect of this RanGTP-induced global conformational change to the NES-binding cleft by shifting its population to the open state, which displays enhanced cargo affinity. Cooperative CRM1 export complex assembly thus constitutes a highly dynamic process, encompassing an intricate interplay of global and local structural changes.
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Affiliation(s)
- Nicole Dölker
- Abteilung für Theoretische und Computergestützte Biophysik, Max-Planck-Institut für Biophysikalische Chemie, Am Faßberg 11, 37077 Göttingen, Germany
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Dian C, Bernaudat F, Langer K, Oliva MF, Fornerod M, Schoehn G, Müller CW, Petosa C. Structure of a truncation mutant of the nuclear export factor CRM1 provides insights into the auto-inhibitory role of its C-terminal helix. Structure 2013; 21:1338-49. [PMID: 23850454 DOI: 10.1016/j.str.2013.06.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2013] [Revised: 06/12/2013] [Accepted: 06/13/2013] [Indexed: 11/23/2022]
Abstract
Chromosome region maintenance 1/exportin1/Xpo1 (CRM1) associates with the GTPase Ran to mediate the nuclear export of proteins bearing a leucine-rich nuclear export signal (NES). CRM1 consists of helical hairpin HEAT repeats and a C-terminal helical extension (C-extension) that inhibits the binding of NES-bearing cargos. We report the crystal structure and small-angle X-ray scattering analysis of a human CRM1 mutant with enhanced NES-binding activity due to deletion of the C-extension. We show that loss of the C-extension leads to a repositioning of CRM1's C-terminal repeats and to a more extended overall conformation. Normal mode analysis predicts reduced rigidity for the deletion mutant, consistent with an observed decrease in thermal stability. Point mutations that destabilize the C-extension shift CRM1 to the more extended conformation, reduce thermal stability, and enhance NES-binding activity. These findings suggest that an important mechanism by which the C-extension regulates CRM1's cargo-binding affinity is by modulating the conformation and flexibility of its HEAT repeats.
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Affiliation(s)
- Cyril Dian
- Université de Grenoble Alpes, Institut de Biologie Structurale, 38027 Grenoble, France
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Wu Z, Jiang Q, Clarke PR, Zhang C. Phosphorylation of Crm1 by CDK1-cyclin-B promotes Ran-dependent mitotic spindle assembly. J Cell Sci 2013; 126:3417-28. [PMID: 23729730 DOI: 10.1242/jcs.126854] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Mitotic spindle assembly in animal cells is orchestrated by a chromosome-dependent pathway that directs microtubule stabilization. RanGTP generated at chromosomes releases spindle assembly factors from inhibitory complexes with importins, the nuclear transport factors that facilitate protein import into the nucleus during interphase. In addition, the nuclear export factor Crm1 has been proposed to act as a mitotic effector of RanGTP through the localized assembly of protein complexes on the mitotic spindle, notably at centrosomes and kinetochores. It has been unclear, however, how the functions of nuclear transport factors are controlled during mitosis. Here, we report that human Crm1 is phosphorylated at serine 391 in mitosis by CDK1-cyclin-B (i.e. the CDK1 and cyclin B complex). Expression of Crm1 with serine 391 mutated to either non-phosphorylated or phosphorylation-mimicking residues indicates that phosphorylation directs the localization of Crm1 to the mitotic spindle and facilitates spindle assembly, microtubule stabilization and chromosome alignment. We find that phosphorylation of Crm1 at serine 391 enhances its RanGTP-dependent interaction with RanGAP1-RanBP2 and promotes their recruitment to the mitotic spindle. These results show that phosphorylation of Crm1 controls its molecular interactions, localization and function during mitosis, uncovering a new mechanism for the control of mitotic spindle assembly by CDK1-cyclin-B. We propose that nuclear transport factors are controlled during mitosis through the selection of specific molecular interactions by protein phosphorylation.
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Affiliation(s)
- Zhige Wu
- The MOE Key Laboratory of Cell Proliferation and Differentiation and the State Key Laboratory of Bio-membrane and Membrane Bio-engineering, College of Life Sciences, Peking University, Beijing 100871, China
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Role of immediate early protein ICP27 in the differential sensitivity of herpes simplex viruses 1 and 2 to leptomycin B. J Virol 2013; 87:8940-51. [PMID: 23740995 DOI: 10.1128/jvi.00633-13] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Leptomycin B (LMB) is a highly specific inhibitor of CRM1, a cellular karyopherin-β that transports nuclear export signal-containing proteins from the nucleus to the cytoplasm. Previous work has shown that LMB blocks herpes simplex virus 1 (HSV-1) replication in Vero cells and that certain mutations in viral immediate early protein ICP27 can confer LMB resistance. However, little is known of the molecular mechanisms involved. Here we report that HSV-2, a close relative of HSV-1, is naturally resistant to LMB. To see whether the ICP27 gene determines this phenotypic difference, we generated an HSV-1 mutant that expresses the HSV-2 ICP27 instead of the HSV-1 protein. This recombinant was fully sensitive to LMB, indicating that one or more other viral genes must be important in determining HSV-2's LMB-resistant phenotype. In additional work, we report several findings that shed light on how HSV-1 ICP27 mutations can confer LMB resistance. First, we show that LMB treatment of HSV-1-infected cells leads to suppression of late viral protein synthesis and a block to progeny virion release. Second, we identify a novel type of ICP27 mutation that can confer LMB resistance, that being the addition of a 100-residue amino-terminal affinity purification tag. Third, by studying infections where both LMB-sensitive and LMB-resistant forms of ICP27 are present, we show that HSV-1's sensitivity to LMB is dominant to its resistance. Together, our results suggest a model in which the N-terminal portion of ICP27 mediates a nonessential activity that interferes with HSV-1 replication when CRM1 is inactive. We suggest that LMB resistance mutations weaken or abrogate this activity.
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