1
|
Hazawa M, Ikliptikawati DK, Iwashima Y, Lin DC, Jiang Y, Qiu Y, Makiyama K, Matsumoto K, Kobayashi A, Nishide G, Keesiang L, Yoshino H, Minamoto T, Suzuki T, Kobayashi I, Meguro-Horike M, Jiang YY, Nishiuchi T, Konno H, Koeffler HP, Hosomichi K, Tajima A, Horike SI, Wong RW. Super-enhancer trapping by the nuclear pore via intrinsically disordered regions of proteins in squamous cell carcinoma cells. Cell Chem Biol 2024; 31:792-804.e7. [PMID: 37924814 DOI: 10.1016/j.chembiol.2023.10.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 08/07/2023] [Accepted: 10/10/2023] [Indexed: 11/06/2023]
Abstract
Master transcription factors such as TP63 establish super-enhancers (SEs) to drive core transcriptional networks in cancer cells, yet the spatiotemporal regulation of SEs within the nucleus remains unknown. The nuclear pore complex (NPC) may tether SEs to the nuclear pore where RNA export rates are maximal. Here, we report that NUP153, a component of the NPC, anchors SEs to the NPC and enhances TP63 expression by maximizing mRNA export. This anchoring is mediated through protein-protein interaction between the intrinsically disordered regions (IDRs) of NUP153 and the coactivator BRD4. Silencing of NUP153 excludes SEs from the nuclear periphery, decreases TP63 expression, impairs cellular growth, and induces epidermal differentiation of squamous cell carcinoma. Overall, this work reveals the critical roles of NUP153 IDRs in the regulation of SE localization, thus providing insights into a new layer of gene regulation at the epigenomic and spatial level.
Collapse
Affiliation(s)
- Masaharu Hazawa
- Cell-Bionomics Research Unit, Innovative Integrated Bio-Research Core, Institute for Frontier Science Initiative, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan; WPI Nano Life Science Institute, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan; Faculty of Biological Science and Technology, Institute of Science and Engineering, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan; Laboratory of molecular cell biology, School of Natural System, Institute of Science and Engineering, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan.
| | - Dini Kurnia Ikliptikawati
- Cell-Bionomics Research Unit, Innovative Integrated Bio-Research Core, Institute for Frontier Science Initiative, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
| | - Yuki Iwashima
- Laboratory of molecular cell biology, School of Natural System, Institute of Science and Engineering, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
| | - De-Chen Lin
- Herman Ostrow School of Dentistry, Center for Craniofacial Molecular Biology, Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, Los Angeles, CA, USA
| | - Yuan Jiang
- Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, P.R.China; University of Science and Technology of China, Hefei 230026, P.R.China
| | - Yujia Qiu
- WPI Nano Life Science Institute, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
| | - Kei Makiyama
- Division of Transdisciplinary Sciences, Graduate School of Frontier Science Initiative, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
| | - Koki Matsumoto
- Division of Transdisciplinary Sciences, Graduate School of Frontier Science Initiative, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
| | - Akiko Kobayashi
- Cell-Bionomics Research Unit, Innovative Integrated Bio-Research Core, Institute for Frontier Science Initiative, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
| | - Goro Nishide
- WPI Nano Life Science Institute, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
| | - Lim Keesiang
- WPI Nano Life Science Institute, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
| | - Hironori Yoshino
- Department of Radiation Science, Hirosaki University Graduate School of Health Sciences, Hirosaki, Aomori 036-8564, Japan
| | - Toshinari Minamoto
- Division of Translational and Clinical Oncology, Cancer Research Institute, Kanazawa University, Takara-machi, Kanazawa, Ishikawa 920-8640, Japan
| | - Takeshi Suzuki
- Division of Functional Genomics, Cancer Research Institute, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
| | - Isao Kobayashi
- Faculty of Biological Science and Technology, Institute of Science and Engineering, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
| | - Makiko Meguro-Horike
- Advanced Science Research Center, Institute for Gene Research, Kanazawa University, Takara-machi, Kanazawa, Ishikawa 920-8640, Japan
| | - Yan-Yi Jiang
- Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, P.R.China; University of Science and Technology of China, Hefei 230026, P.R.China
| | - Takumi Nishiuchi
- Division of Integrated Omics research, Bioscience Core Facility Research Center for Experimental Modeling of Human Disease, Kanazawa University 13-1 Takara-machi, Kanazawa, Ishikawa 920-8640, Japan
| | - Hiroki Konno
- WPI Nano Life Science Institute, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
| | - H Phillip Koeffler
- Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Kazuyoshi Hosomichi
- Laboratory of Computational Genomics, School of Life Science, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
| | - Atsushi Tajima
- Department of Bioinformatics and Genomics, Graduate School of Advanced Preventive Medical Sciences, Kanazawa University, Takara-machi, Kanazawa, Ishikawa 920-8640, Japan
| | - Shin-Ichi Horike
- Cell-Bionomics Research Unit, Innovative Integrated Bio-Research Core, Institute for Frontier Science Initiative, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan; Advanced Science Research Center, Institute for Gene Research, Kanazawa University, Takara-machi, Kanazawa, Ishikawa 920-8640, Japan
| | - Richard W Wong
- Cell-Bionomics Research Unit, Innovative Integrated Bio-Research Core, Institute for Frontier Science Initiative, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan; WPI Nano Life Science Institute, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan; Faculty of Biological Science and Technology, Institute of Science and Engineering, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan; Laboratory of molecular cell biology, School of Natural System, Institute of Science and Engineering, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan.
| |
Collapse
|
2
|
Meng C, Chen G, Wen D, Dong L, Cui X, Jing X, Cui J, Gao Y, Liu Y, Bu H, Wu C. The expression of Nramp1 modulates the uptake of Mycobacterium tuberculosis by macrophages through alternating inflammatory responses. Tuberculosis (Edinb) 2023; 143:102414. [PMID: 37820457 DOI: 10.1016/j.tube.2023.102414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 09/23/2023] [Accepted: 09/26/2023] [Indexed: 10/13/2023]
Abstract
Natural-resistance-associated macrophage protein-1 (NRAMP1) is a transmembrane protein of the mammalian SLC11 gene family. Previously, genome-wide association study (GWAS) have shown that the single nucleotide polymorphisms (SNPs) of NRAMP1 are associated with human susceptibility to tuberculosis (TB), and the detection of clinical samples have demonstrated that the expression levels of NRAMP1 are concomitant with the susceptibility to TB in humans and cows, but underlying mechanism is unknown. In this study, we completed a series of experiments to investigate how the expression of Nramp1 affects the infection of macrophages with Mycobacterium tuberculosis (Mtb). We found that the increase of Nramp1 expression induced the decrease of Mtb infection efficiency and the higher-level expression of pro-inflammatory cytokines and chemokines, However, the knockdown of Nramp1 promoted the efficiency of bacilli infection to macrophages and induced lower-levels of expression of pro-inflammatory cytokines and chemokines. Collectively, the results in this study demonstrated that the levels of Nramp1 expression affect Mtb infection of macrophage and regulate pro-inflammatory responses of macrophages to Mtb infection, indicating the population with the low-expression level of NRAMP1 predispose to Mtb infection and TB development, and suggesting SNPs in NRAMP1 modulate the host susceptibility to TB through its regulation of NRAMP1 expression.
Collapse
Affiliation(s)
- Chaoqun Meng
- The Key Laboratory of Medical Molecular Cell Biology of Shanxi Province, Institute of Biomedical Sciences, Shanxi University, 92 Wucheng Road, Taiyuan, 030006, Shanxi province, China; The Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education of China, Institute of Biotechnology, Shanxi University, Taiyuan, 030006, Shanxi province, China; The Key Laboratory of the Prevention and Control of Major Infectious Disease of Shanxi Province, Shanxi University, Taiyuan, 030006, Shanxi province, China
| | - Guangxin Chen
- The Key Laboratory of Medical Molecular Cell Biology of Shanxi Province, Institute of Biomedical Sciences, Shanxi University, 92 Wucheng Road, Taiyuan, 030006, Shanxi province, China
| | - Da Wen
- The Key Laboratory of Medical Molecular Cell Biology of Shanxi Province, Institute of Biomedical Sciences, Shanxi University, 92 Wucheng Road, Taiyuan, 030006, Shanxi province, China
| | - Li Dong
- The Key Laboratory of Medical Molecular Cell Biology of Shanxi Province, Institute of Biomedical Sciences, Shanxi University, 92 Wucheng Road, Taiyuan, 030006, Shanxi province, China
| | - Xiaogang Cui
- The Key Laboratory of Medical Molecular Cell Biology of Shanxi Province, Institute of Biomedical Sciences, Shanxi University, 92 Wucheng Road, Taiyuan, 030006, Shanxi province, China
| | - Xuejiao Jing
- The Key Laboratory of Medical Molecular Cell Biology of Shanxi Province, Institute of Biomedical Sciences, Shanxi University, 92 Wucheng Road, Taiyuan, 030006, Shanxi province, China
| | - Jia Cui
- Department of Microbiology, Changzhi Medical College, 161 Jiefang Road, Changzhi, 046000, Shanxi province, China
| | - Yuanting Gao
- The Key Laboratory of Medical Molecular Cell Biology of Shanxi Province, Institute of Biomedical Sciences, Shanxi University, 92 Wucheng Road, Taiyuan, 030006, Shanxi province, China
| | - Yue Liu
- The Key Laboratory of Medical Molecular Cell Biology of Shanxi Province, Institute of Biomedical Sciences, Shanxi University, 92 Wucheng Road, Taiyuan, 030006, Shanxi province, China
| | - Hongli Bu
- The Fourth People's Hospital of Taiyuan, 231 Xikuang Street, Taiyuan, 030053, Shanxi province, China.
| | - Changxin Wu
- The Key Laboratory of Medical Molecular Cell Biology of Shanxi Province, Institute of Biomedical Sciences, Shanxi University, 92 Wucheng Road, Taiyuan, 030006, Shanxi province, China; The Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education of China, Institute of Biotechnology, Shanxi University, Taiyuan, 030006, Shanxi province, China; The Fourth People's Hospital of Taiyuan, 231 Xikuang Street, Taiyuan, 030053, Shanxi province, China; The Key Laboratory of the Prevention and Control of Major Infectious Disease of Shanxi Province, Shanxi University, Taiyuan, 030006, Shanxi province, China.
| |
Collapse
|
3
|
Ong JY, Torres JZ. Cul3 substrate adaptor SPOP targets Nup153 for degradation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.13.540659. [PMID: 37293018 PMCID: PMC10245568 DOI: 10.1101/2023.05.13.540659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
SPOP is a Cul3 substrate adaptor responsible for degradation of many proteins related to cell growth and proliferation. Because mutation or misregulation of SPOP drives cancer progression, understanding the suite of SPOP substrates is important to understanding regulation of cell proliferation. Here, we identify Nup153, a component of the nuclear basket of the nuclear pore complex, as a novel substrate of SPOP. SPOP and Nup153 bind to each other and colocalize at the nuclear envelope and some nuclear foci in cells. The binding interaction between SPOP and Nup153 is complex and multivalent. Nup153 is ubiquitylated and degraded upon expression of SPOPWT but not its substrate binding-deficient mutant SPOPF102C. Depletion of SPOP via RNAi leads to Nup153 stabilization. Upon loss of SPOP, the nuclear envelope localization of spindle assembly checkpoint protein Mad1, which is tethered to the nuclear envelope by Nup153, is stronger. Altogether, our results demonstrate SPOP regulates Nup153 levels and expands our understanding of the role of SPOP in protein and cellular homeostasis.
Collapse
Affiliation(s)
- Joseph Y Ong
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Jorge Z Torres
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
- Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA
- Jonsson Comprehensive Cancer Center, University of California, Los Angeles, Los Angeles, CA 90095, USA
| |
Collapse
|
4
|
Tingey M, Li Y, Yu W, Young A, Yang W. Spelling out the roles of individual nucleoporins in nuclear export of mRNA. Nucleus 2022; 13:170-193. [PMID: 35593254 PMCID: PMC9132428 DOI: 10.1080/19491034.2022.2076965] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 05/08/2022] [Accepted: 05/09/2022] [Indexed: 11/01/2022] Open
Abstract
The Nuclear Pore Complex (NPC) represents a critical passage through the nuclear envelope for nuclear import and export that impacts nearly every cellular process at some level. Recent technological advances in the form of Auxin Inducible Degron (AID) strategies and Single-Point Edge-Excitation sub-Diffraction (SPEED) microscopy have enabled us to provide new insight into the distinct functions and roles of nuclear basket nucleoporins (Nups) upon nuclear docking and export for mRNAs. In this paper, we provide a review of our recent findings as well as an assessment of new techniques, updated models, and future perspectives in the studies of mRNA's nuclear export.
Collapse
Affiliation(s)
- Mark Tingey
- Department of Biology, Temple University, Philadelphia, Pennsylvania, USA
| | - Yichen Li
- Department of Genetics, Yale School of Medicine, Yale University, New Haven, Connecticut, USA
| | - Wenlan Yu
- Department of Biology, Temple University, Philadelphia, Pennsylvania, USA
| | - Albert Young
- Department of Biology, Temple University, Philadelphia, Pennsylvania, USA
| | - Weidong Yang
- Department of Biology, Temple University, Philadelphia, Pennsylvania, USA
| |
Collapse
|
5
|
LaJoie D, Turkmen AM, Mackay DR, Jensen CC, Aksenova V, Niwa M, Dasso M, Ullman KS. A role for Nup153 in nuclear assembly reveals differential requirements for targeting of nuclear envelope constituents. Mol Biol Cell 2022; 33:ar117. [PMID: 36044344 PMCID: PMC9634965 DOI: 10.1091/mbc.e22-05-0189] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Assembly of the nucleus following mitosis requires rapid and coordinate recruitment of diverse constituents to the inner nuclear membrane. We have identified an unexpected role for the nucleoporin Nup153 in promoting the continued addition of a subset of nuclear envelope (NE) proteins during initial expansion of nascent nuclei. Specifically, disrupting the function of Nup153 interferes with ongoing addition of B-type lamins, lamin B receptor, and SUN1 early in telophase, after the NE has initially enclosed chromatin. In contrast, effects on lamin A and SUN2 were minimal, pointing to differential requirements for the ongoing targeting of NE proteins. Further, distinct mistargeting phenotypes arose among the proteins that require Nup153 for NE targeting. Thus, disrupting the function of Nup153 in nuclear formation reveals several previously undescribed features important for establishing nuclear architecture: 1) a role for a nuclear basket constituent in ongoing recruitment of nuclear envelope components, 2) two functionally separable phases of NE formation in mammalian cells, and 3) distinct requirements of individual NE residents for continued targeting during the expansion phase of NE reformation.
Collapse
Affiliation(s)
- Dollie LaJoie
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112
| | - Ayse M. Turkmen
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112
| | - Douglas R. Mackay
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112
| | - Christopher C. Jensen
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112
| | - Vasilisa Aksenova
- Division of Molecular and Cellular Biology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892
| | - Maho Niwa
- Division of Biological Sciences, Section of Molecular Biology, University of California, San Diego, La Jolla, CA 92093
| | - Mary Dasso
- Division of Molecular and Cellular Biology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892
| | - Katharine S. Ullman
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112,*Address correspondence to: Katharine S. Ullman (
.edu)
| |
Collapse
|
6
|
Tingey M, Yang W. Unraveling docking and initiation of mRNA export through the nuclear pore complex. Bioessays 2022; 44:e2200027. [PMID: 35754154 PMCID: PMC9308666 DOI: 10.1002/bies.202200027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 05/18/2022] [Accepted: 06/03/2022] [Indexed: 11/07/2022]
Abstract
The nuclear export of mRNA through the nuclear pore complex (NPC) is a process required for the healthy functioning of human cells, making it a critical area of research. However, the geometries of mRNA and the NPC are well below the diffraction limit of light microscopy, thereby presenting significant challenges in evaluating the discrete interactions and dynamics involved in mRNA nuclear export through the native NPC. Recent advances in biotechnology and single-molecule super-resolution light microscopy have enabled researchers to gain granular insight into the specific contributions made by discrete nucleoporins in the nuclear basket of the NPC to the export of mRNA. Specifically, by expanding upon the docking step facilitated by the protein TPR in the nuclear basket as well as identifying NUP153 as being the primary nuclear basket protein initiating export through the central channel of the NPC.
Collapse
Affiliation(s)
- Mark Tingey
- Department of Biology, Temple University, Philadelphia, Pennsylvania, USA
| | - Weidong Yang
- Department of Biology, Temple University, Philadelphia, Pennsylvania, USA
| |
Collapse
|
7
|
Yoo TY, Mitchison TJ. O-GlcNAc modification of nuclear pore complexes accelerates bidirectional transport. J Cell Biol 2021; 220:212033. [PMID: 33909044 PMCID: PMC8091080 DOI: 10.1083/jcb.202010141] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Revised: 02/28/2021] [Accepted: 03/17/2021] [Indexed: 01/09/2023] Open
Abstract
Macromolecular transport across the nuclear envelope depends on facilitated diffusion through nuclear pore complexes (NPCs). The interior of NPCs contains a permeability barrier made of phenylalanine-glycine (FG) repeat domains that selectively facilitates the permeation of cargoes bound to nuclear transport receptors (NTRs). FG-repeat domains in NPCs are a major site of O-linked N-acetylglucosamine (O-GlcNAc) modification, but the functional role of this modification in nucleocytoplasmic transport is unclear. We developed high-throughput assays based on optogenetic probes to quantify the kinetics of nuclear import and export in living human cells. We found that increasing O-GlcNAc modification of the NPC accelerated NTR-facilitated transport of proteins in both directions, and decreasing modification slowed transport. Superresolution imaging revealed strong enrichment of O-GlcNAc at the FG-repeat barrier. O-GlcNAc modification also accelerated passive permeation of a small, inert protein through NPCs. We conclude that O-GlcNAc modification accelerates nucleocytoplasmic transport by enhancing the nonspecific permeability of the FG-repeat barrier, perhaps by steric inhibition of interactions between FG repeats.
Collapse
Affiliation(s)
- Tae Yeon Yoo
- Department of Systems Biology, Blavatnik Institute, Harvard Medical School, Boston, MA
| | - Timothy J Mitchison
- Department of Systems Biology, Blavatnik Institute, Harvard Medical School, Boston, MA
| |
Collapse
|
8
|
Liu Y, Trnka MJ, Guan S, Kwon D, Kim DH, Chen JJ, Greer PA, Burlingame AL, Correia MA. A Novel Mechanism for NF-κB-activation via IκB-aggregation: Implications for Hepatic Mallory-Denk-Body Induced Inflammation. Mol Cell Proteomics 2020; 19:1968-1986. [PMID: 32912968 PMCID: PMC7710137 DOI: 10.1074/mcp.ra120.002316] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Indexed: 11/06/2022] Open
Abstract
Mallory-Denk-bodies (MDBs) are hepatic protein aggregates associated with inflammation both clinically and in MDB-inducing models. Similar protein aggregation in neurodegenerative diseases also triggers inflammation and NF-κB activation. However, the precise mechanism that links protein aggregation to NF-κB-activation and inflammatory response remains unclear. Herein we find that treating primary hepatocytes with MDB-inducing agents (N-methylprotoporphyrin (NMPP), protoporphyrin IX (PPIX), or Zinc-protoporphyrin IX (ZnPP)) elicited an IκBα-loss with consequent NF-κB activation. Four known mechanisms of IκBα-loss i.e. the canonical ubiquitin-dependent proteasomal degradation (UPD), autophagic-lysosomal degradation, calpain degradation and translational inhibition, were all probed and excluded. Immunofluorescence analyses of ZnPP-treated cells coupled with 8 M urea/CHAPS-extraction revealed that this IκBα-loss was due to its sequestration along with IκBβ into insoluble aggregates, thereby releasing NF-κB. Through affinity pulldown, proximity biotinylation by antibody recognition, and other proteomic analyses, we verified that NF-κB subunit p65, which stably interacts with IκBα under normal conditions, no longer binds to it upon ZnPP-treatment. Additionally, we identified 10 proteins that interact with IκBα under baseline conditions, aggregate upon ZnPP-treatment, and maintain the interaction with IκBα after ZnPP-treatment, either by cosequestering into insoluble aggregates or through a different mechanism. Of these 10 proteins, the nucleoporins Nup153 and Nup358/RanBP2 were identified through RNA-interference, as mediators of IκBα-nuclear import. The concurrent aggregation of IκBα, NUP153, and RanBP2 upon ZnPP-treatment, synergistically precluded the nuclear entry of IκBα and its consequent binding and termination of NF-κB activation. This novel mechanism may account for the protein aggregate-induced inflammation observed in liver diseases, thus identifying novel targets for therapeutic intervention. Because of inherent commonalities this MDB cell model is a bona fide protoporphyric model, making these findings equally relevant to the liver inflammation associated with clinical protoporphyria.
Collapse
Affiliation(s)
- Yi Liu
- Departments of Cellular & Molecular Pharmacology, University of California San Francisco, San Francisco, California, USA
| | - Michael J Trnka
- Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California, USA
| | - Shenheng Guan
- Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California, USA
| | - Doyoung Kwon
- Departments of Cellular & Molecular Pharmacology, University of California San Francisco, San Francisco, California, USA
| | - Do-Hyung Kim
- Departments of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, USA
| | - J-J Chen
- Institute for Medical Engineering and Science, MIT, Cambridge, Massachusetts, USA
| | - Peter A Greer
- Department of Pathology and Molecular Medicine, Queen's University, Kingston, Ontario, Canada
| | - A L Burlingame
- Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California, USA
| | - Maria Almira Correia
- Departments of Cellular & Molecular Pharmacology, University of California San Francisco, San Francisco, California, USA; Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California, USA; Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, California, USA; The Liver Center, University of California San Francisco, San Francisco, California, USA.
| |
Collapse
|
9
|
Mossaid I, Chatel G, Martinelli V, Vaz M, Fahrenkrog B. Mitotic checkpoint protein Mad1 is required for early Nup153 recruitment to chromatin and nuclear envelope integrity. J Cell Sci 2020; 133:jcs249243. [PMID: 33023979 DOI: 10.1242/jcs.249243] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 09/24/2020] [Indexed: 11/20/2022] Open
Abstract
Nucleoporin Nup153 is a multifunctional protein and a known binding partner of mitotic checkpoint protein Mad1 (also known as MAD1L1). The functional relevance of their interaction has remained elusive. Here, we have further dissected the interface and functional interplay of Nup153 and Mad1. Using in situ proximity ligation assays, we found that the presence of a nuclear envelope (NE) is a prerequisite for the Nup153-Mad1 association. Time-lapse microscopy revealed that depletion of Mad1 delayed recruitment of Nup153 to anaphase chromatin, which was often accompanied by a prolongation of anaphase. Furthermore, as seen by electron microscopic and three-dimensional structured illumination investigations, Nup153 and Mad1 depletion led to alterations in NE architecture, characterised by a change of membrane curvature at nuclear pore complexes (NPCs) and an expansion of the spacing between inner and outer nuclear membranes. Nup153 depletion, but not Mad1 depletion, caused defects in interphase NPC assembly, with partial displacement of cytoplasmic nucleoporins and a reduction in NPC density. Taken together, our results suggest that Nup153 has separable roles in NE and NPC formation: in post-mitotic NE re-formation in concert with Mad1 and in interphase NPC assembly, independent of Mad1.
Collapse
Affiliation(s)
- Ikram Mossaid
- Institute of Molecular Biology and Medicine, Laboratory Biologie du Noyau, Université Libre de Bruxelles, 6041 Charleroi, Belgium
| | - Guillaume Chatel
- Institute of Molecular Biology and Medicine, Laboratory Biologie du Noyau, Université Libre de Bruxelles, 6041 Charleroi, Belgium
| | - Valérie Martinelli
- Institute of Molecular Biology and Medicine, Laboratory Biologie du Noyau, Université Libre de Bruxelles, 6041 Charleroi, Belgium
| | - Marcela Vaz
- Institute of Molecular Biology and Medicine, Laboratory Biologie du Noyau, Université Libre de Bruxelles, 6041 Charleroi, Belgium
| | - Birthe Fahrenkrog
- Institute of Molecular Biology and Medicine, Laboratory Biologie du Noyau, Université Libre de Bruxelles, 6041 Charleroi, Belgium
| |
Collapse
|
10
|
Cytoplasmic Parvovirus Capsids Recruit Importin Beta for Nuclear Delivery. J Virol 2020; 94:JVI.01532-19. [PMID: 31748386 DOI: 10.1128/jvi.01532-19] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 11/16/2019] [Indexed: 02/06/2023] Open
Abstract
Parvoviruses are an important platform for gene and cancer therapy. Their cell entry and the following steps, including nuclear import, are inefficient, limiting their use in therapeutic applications. Two models exist on parvoviral nuclear entry: the classical import of the viral capsid using nuclear transport receptors of the importin (karyopherin) family or the direct attachment of the capsid to the nuclear pore complex leading to the local disintegration of the nuclear envelope. Here, by laser scanning confocal microscopy and in situ proximity ligation analyses combined with coimmunoprecipitation, we show that infection requires importin β-mediated access to the nuclear pore complex and nucleoporin 153-mediated interactions on the nuclear side. The importin β-capsid interaction continued within the nucleoplasm, which suggests a mixed model of nuclear entry in which the classical nuclear import across the nuclear pore complex is accompanied by transient ruptures of the nuclear envelope, also allowing the passive entry of importin β-capsid complexes into the nucleus.IMPORTANCE Parvoviruses are small DNA viruses that deliver their DNA into the postmitotic nuclei, which is an important step for parvoviral gene and cancer therapies. Limitations in virus-receptor interactions or endocytic entry do not fully explain the low transduction/infection efficiency, indicating a bottleneck after virus entry into the cytoplasm. We thus investigated the transfer of parvovirus capsids from the cytoplasm to the nucleus, showing that the nuclear import of the parvovirus capsid follows a unique strategy, which differs from classical nuclear import and those of other viruses.
Collapse
|
11
|
Shukla E, Chauhan R. Host-HIV-1 Interactome: A Quest for Novel Therapeutic Intervention. Cells 2019; 8:cells8101155. [PMID: 31569640 PMCID: PMC6830350 DOI: 10.3390/cells8101155] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 09/09/2019] [Accepted: 09/09/2019] [Indexed: 12/15/2022] Open
Abstract
The complex nature and structure of the human immunodeficiency virus has rendered the cure for HIV infections elusive. The advances in antiretroviral treatment regimes and the development of highly advanced anti-retroviral therapy, which primarily targets the HIV enzymes, have dramatically changed the face of the HIV epidemic worldwide. Despite this remarkable progress, patients treated with these drugs often witness inadequate efficacy, compound toxicity and non-HIV complications. Considering the limited inventory of druggable HIV proteins and their susceptibility to develop drug resistance, recent attempts are focussed on targeting HIV-host interactomes that are essential for viral reproduction. Noticeably, unlike other viruses, HIV subverts the host nuclear pore complex to enter into and exit through the nucleus. Emerging evidence suggests a crucial role of interactions between HIV-1 proteins and host nucleoporins that underlie the import of the pre-integration complex into the nucleus and export of viral RNAs into the cytoplasm during viral replication. Nevertheless, the interaction of HIV-1 with nucleoporins has been poorly described and the role of nucleoporins during nucleocytoplasmic transport of HIV-1 still remains unclear. In this review, we highlight the advances and challenges in developing a more effective antiviral arsenal by exploring critical host-HIV interactions with a special focus on nuclear pore complex (NPC) and nucleoporins.
Collapse
Affiliation(s)
- Ekta Shukla
- National Center for Cell Science, S.P Pune University, Pune-411007, Maharashtra, India.
| | - Radha Chauhan
- National Center for Cell Science, S.P Pune University, Pune-411007, Maharashtra, India.
| |
Collapse
|
12
|
Donnaloja F, Jacchetti E, Soncini M, Raimondi MT. Mechanosensing at the Nuclear Envelope by Nuclear Pore Complex Stretch Activation and Its Effect in Physiology and Pathology. Front Physiol 2019; 10:896. [PMID: 31354529 PMCID: PMC6640030 DOI: 10.3389/fphys.2019.00896] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 06/27/2019] [Indexed: 02/03/2023] Open
Abstract
Cell fate is correlated to mechanotransduction, in which forces transmitted by the cytoskeleton filaments alter the nuclear shape, affecting transcription factor import/export, cells transcription activity and chromatin distribution. There is in fact evidence that stem cells cultured in 3D environments mimicking the native niche are able to maintain their stemness or modulate their cellular function. However, the molecular and biophysical mechanisms underlying cellular mechanosensing are still largely unclear. The propagation of mechanical stimuli via a direct pathway from cell membrane integrins to SUN proteins residing in the nuclear envelop has been demonstrated, but we suggest that the cells’ fate is mainly affected by the force distribution at the nuclear envelope level, where the SUN protein transmits the stimuli via its mechanical connection to several cell structures such as chromatin, lamina and the nuclear pore complex (NPC). In this review, we analyze the NPC structure and organization, which have not as yet been fully investigated, and its plausible involvement in cell fate. NPC is a multiprotein complex that spans the nuclear envelope, and is involved in several key cellular processes such as bidirectional nucleocytoplasmic exchange, cell cycle regulation, kinetochore organization, and regulation of gene expression. As several connections between the NPC and the nuclear envelope, chromatin and other transmembrane proteins have been identified, it is reasonable to suppose that nuclear deformations can alter the NPC structure. We provide evidence that the transmission of mechanical forces may significantly affects the basket conformation via the Nup153-SUN1 connection, both altering the passage of molecules through it and influencing the state of chromatin packing. Finally, we review the known correlations between a pathological NPC structure and diseases such as cancer, autoimmune disease, aging and laminopathies.
Collapse
Affiliation(s)
- F Donnaloja
- Department of Chemistry, Materials and Chemical Engineering "Giulio Natta," Politecnico di Milano, Milan, Italy
| | - E Jacchetti
- Department of Chemistry, Materials and Chemical Engineering "Giulio Natta," Politecnico di Milano, Milan, Italy
| | - M Soncini
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy
| | - M T Raimondi
- Department of Chemistry, Materials and Chemical Engineering "Giulio Natta," Politecnico di Milano, Milan, Italy
| |
Collapse
|
13
|
Wu Y, Fang G, Wang X, Wang H, Chen W, Li L, Ye T, Gong L, Ke C, Cai Y. NUP153 overexpression suppresses the proliferation of colorectal cancer by negatively regulating Wnt/β-catenin signaling pathway and predicts good prognosis. Cancer Biomark 2019; 24:61-70. [PMID: 30347601 DOI: 10.3233/cbm-181703] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Nucleoporin NUP153 (NUP153) is well known to be involved in the regulating of nuclear transport. Although NUP153 is associated with several cancers, its role in colorectal cancer (CRC) and the underlying mechanism are still unknown. OBJECTIVE The aim of this study was to access the effect of NUP153 on the prognosis of patients with CRC, and cancer cell proliferation. METHODS The expression levels of NUP153 in CRC tissues and matched normal colon tissues were examined by real-time quantitative PCR and immunohistochemistry. Then the association between NUP153 levels with clinical variables as well as survival time was investigated. Moreover, overexpression of NUP153 in HCT116 cells was established to study its influence on cell proliferation in vitro, and a xenograft model was performed to explore this effect in vivo. RESULTS We found that NUP153 was highly expressed in adjacent normal tissues than in cancer tissues, and elevated NUP153 expression was negatively associated with pathological grade (P= 0.015), T stage (P= 0.048) and distant metastasis (P= 0.006). Kaplan-Meier analysis revealed that patients with higher NUP153 expression had a longer overall survival (OS) (P= 0.01) and recurrence free disease (RFS) (P= 0.001). Logistic regression analysis further identified NUP153 as an independent prognostic safe factor for OS and recurrence. Moreover, NUP153 overexpression suppressed CRC cells proliferation and inhibited tumor growth in a xenograft model. Its mechanistic investigations showed that NUP153 overexpression inhibited β-catenin transcriptional activity and down-regulated the mRNA expression levels of Wnt downstream proteins-Axin2, cyclinD1, c-myc and lef-1. CONCLUSIONS NUP153 might be a promising prognostic factor, a potential tumor suppressor and therapeutic target in human CRC through an interaction with the Wnt/β-catenin signaling pathway.
Collapse
Affiliation(s)
- Yibin Wu
- Department of General Surgery, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai 200240, China
| | - Guojiu Fang
- Department of General Surgery, Fengxian District Central Hospital of Shanghai, Shanghai 201499, China
| | - Xin Wang
- Department of General Surgery, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai 200240, China
| | - Huipeng Wang
- Department of General Surgery, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai 200240, China
| | - Wenjie Chen
- Department of General Surgery, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai 200240, China
| | - Liang Li
- Department of General Surgery, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai 200240, China
| | - Tao Ye
- Department of General Surgery, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai 200240, China
| | - Lifeng Gong
- Department of General Surgery, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai 200240, China
| | - Chongwei Ke
- Department of General Surgery, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai 200240, China
| | - Yuankun Cai
- Department of General Surgery, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai 200240, China
| |
Collapse
|
14
|
Zhai W, Wu F, Zhang Y, Fu Y, Liu Z. The Immune Escape Mechanisms of Mycobacterium Tuberculosis. Int J Mol Sci 2019; 20:ijms20020340. [PMID: 30650615 PMCID: PMC6359177 DOI: 10.3390/ijms20020340] [Citation(s) in RCA: 184] [Impact Index Per Article: 36.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 01/09/2019] [Accepted: 01/09/2019] [Indexed: 01/15/2023] Open
Abstract
Epidemiological data from the Center of Disease Control (CDC) and the World Health Organization (WHO) statistics in 2017 show that 10.0 million people around the world became sick with tuberculosis. Mycobacterium tuberculosis (MTB) is an intracellular parasite that mainly attacks macrophages and inhibits their apoptosis. It can become a long-term infection in humans, causing a series of pathological changes and clinical manifestations. In this review, we summarize innate immunity including the inhibition of antioxidants, the maturation and acidification of phagolysosomes and especially the apoptosis and autophagy of macrophages. Besides, we also elaborate on the adaptive immune response and the formation of granulomas. A thorough understanding of these escape mechanisms is of major importance for the prevention, diagnosis and treatment of tuberculosis.
Collapse
Affiliation(s)
- Weijie Zhai
- School of Clinical Medicine, Weifang Medical University, Weifang 261053, China.
| | - Fengjuan Wu
- School of Clinical Medicine, Weifang Medical University, Weifang 261053, China.
| | - Yiyuan Zhang
- School of Clinical Medicine, Weifang Medical University, Weifang 261053, China.
| | - Yurong Fu
- Department of Medical Microbiology, Weifang Medical University, Weifang 261053, China.
| | - Zhijun Liu
- Department of Medical Microbiology, Weifang Medical University, Weifang 261053, China.
| |
Collapse
|
15
|
Platani M, Samejima I, Samejima K, Kanemaki MT, Earnshaw WC. Seh1 targets GATOR2 and Nup153 to mitotic chromosomes. J Cell Sci 2018; 131:jcs.213140. [PMID: 29618633 PMCID: PMC5992584 DOI: 10.1242/jcs.213140] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 03/23/2018] [Indexed: 12/27/2022] Open
Abstract
In metazoa, the Nup107 complex (also known as the nucleoporin Y-complex) plays a major role in formation of the nuclear pore complex in interphase and is localised to kinetochores in mitosis. The Nup107 complex shares a single highly conserved subunit, Seh1 (also known as SEH1L in mammals) with the GATOR2 complex, an essential activator of mTORC1 kinase. mTORC1/GATOR2 has a central role in the coordination of cell growth and proliferation. Here, we use chemical genetics and quantitative chromosome proteomics to study the role of the Seh1 protein in mitosis. Surprisingly, Seh1 is not required for the association of the Nup107 complex with mitotic chromosomes, but it is essential for the association of both the GATOR2 complex and nucleoporin Nup153 with mitotic chromosomes. Our analysis also reveals a role for Seh1 at human centromeres, where it is required for efficient localisation of the chromosomal passenger complex (CPC). Furthermore, this analysis detects a functional interaction between the Nup107 complex and the small kinetochore protein SKAP (also known as KNSTRN). Highlighted Article: The nucleoporin Seh1 is essential for the association of both the GATOR2 complex and the nucleoporin Nup153, but not the Nup107 complex, with mitotic chromosomes.
Collapse
Affiliation(s)
- Melpomeni Platani
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Itaru Samejima
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Kumiko Samejima
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Masato T Kanemaki
- Division of Molecular Cell Engineering, National Institute of Genetics, ROIS, and Department of Genetics, SOKENDAI, Yata 1111, Mishima, Shizuoka 411-8540, Japan
| | - William C Earnshaw
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh EH9 3BF, UK
| |
Collapse
|
16
|
A Cas9 Ribonucleoprotein Platform for Functional Genetic Studies of HIV-Host Interactions in Primary Human T Cells. Cell Rep 2017; 17:1438-1452. [PMID: 27783955 DOI: 10.1016/j.celrep.2016.09.080] [Citation(s) in RCA: 134] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 07/28/2016] [Accepted: 09/22/2016] [Indexed: 12/26/2022] Open
Abstract
New genetic tools are needed to understand the functional interactions between HIV and human host factors in primary cells. We recently developed a method to edit the genome of primary CD4+ T cells by electroporation of CRISPR/Cas9 ribonucleoproteins (RNPs). Here, we adapted this methodology to a high-throughput platform for the efficient, arrayed editing of candidate host factors. CXCR4 or CCR5 knockout cells generated with this method are resistant to HIV infection in a tropism-dependent manner, whereas knockout of LEDGF or TNPO3 results in a tropism-independent reduction in infection. CRISPR/Cas9 RNPs can furthermore edit multiple genes simultaneously, enabling studies of interactions among multiple host and viral factors. Finally, in an arrayed screen of 45 genes associated with HIV integrase, we identified several candidate dependency/restriction factors, demonstrating the power of this approach as a discovery platform. This technology should accelerate target validation for pharmaceutical and cell-based therapies to cure HIV infection.
Collapse
|
17
|
The functional versatility of the nuclear pore complex proteins. Semin Cell Dev Biol 2017; 68:2-9. [DOI: 10.1016/j.semcdb.2017.05.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 05/11/2017] [Indexed: 12/28/2022]
|
18
|
Meyer C, Burmeister T, Gröger D, Tsaur G, Fechina L, Renneville A, Sutton R, Venn NC, Emerenciano M, Pombo-de-Oliveira MS, Barbieri Blunck C, Almeida Lopes B, Zuna J, Trka J, Ballerini P, Lapillonne H, De Braekeleer M, Cazzaniga G, Corral Abascal L, van der Velden VHJ, Delabesse E, Park TS, Oh SH, Silva MLM, Lund-Aho T, Juvonen V, Moore AS, Heidenreich O, Vormoor J, Zerkalenkova E, Olshanskaya Y, Bueno C, Menendez P, Teigler-Schlegel A, Zur Stadt U, Lentes J, Göhring G, Kustanovich A, Aleinikova O, Schäfer BW, Kubetzko S, Madsen HO, Gruhn B, Duarte X, Gameiro P, Lippert E, Bidet A, Cayuela JM, Clappier E, Alonso CN, Zwaan CM, van den Heuvel-Eibrink MM, Izraeli S, Trakhtenbrot L, Archer P, Hancock J, Möricke A, Alten J, Schrappe M, Stanulla M, Strehl S, Attarbaschi A, Dworzak M, Haas OA, Panzer-Grümayer R, Sedék L, Szczepański T, Caye A, Suarez L, Cavé H, Marschalek R. The MLL recombinome of acute leukemias in 2017. Leukemia 2017; 32:273-284. [PMID: 28701730 PMCID: PMC5808070 DOI: 10.1038/leu.2017.213] [Citation(s) in RCA: 470] [Impact Index Per Article: 67.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 04/25/2017] [Accepted: 06/21/2017] [Indexed: 12/16/2022]
Abstract
Chromosomal rearrangements of the human MLL/KMT2A gene are associated with infant, pediatric, adult and therapy-induced acute leukemias. Here we present the data obtained from 2345 acute leukemia patients. Genomic breakpoints within the MLL gene and the involved translocation partner genes (TPGs) were determined and 11 novel TPGs were identified. Thus, a total of 135 different MLL rearrangements have been identified so far, of which 94 TPGs are now characterized at the molecular level. In all, 35 out of these 94 TPGs occur recurrently, but only 9 specific gene fusions account for more than 90% of all illegitimate recombinations of the MLL gene. We observed an age-dependent breakpoint shift with breakpoints localizing within MLL intron 11 associated with acute lymphoblastic leukemia and younger patients, while breakpoints in MLL intron 9 predominate in AML or older patients. The molecular characterization of MLL breakpoints suggests different etiologies in the different age groups and allows the correlation of functional domains of the MLL gene with clinical outcome. This study provides a comprehensive analysis of the MLL recombinome in acute leukemia and demonstrates that the establishment of patient-specific chromosomal fusion sites allows the design of specific PCR primers for minimal residual disease analyses for all patients.
Collapse
Affiliation(s)
- C Meyer
- Institute of Pharmaceutical Biology/Diagnostic Center of Acute Leukemia (DCAL), Goethe-University, Frankfurt/Main, Germany
| | - T Burmeister
- Charité-Department of Hematology, Oncology and Tumorimmunology, Berlin, Germany
| | - D Gröger
- Charité-Department of Hematology, Oncology and Tumorimmunology, Berlin, Germany
| | - G Tsaur
- Regional Children Hospital 1, Research Institute of Medical Cell Technologies, Pediatric Oncology and Hematology Center, Ural Federal University, Ekaterinburg, Russia
| | - L Fechina
- Regional Children Hospital 1, Research Institute of Medical Cell Technologies, Pediatric Oncology and Hematology Center, Ural Federal University, Ekaterinburg, Russia
| | - A Renneville
- Laboratory of Hematology, Biology and Pathology Center, CHRU of Lille; INSERM, UMR-S 1172, Cancer Research Institute of Lille, Lille, France
| | - R Sutton
- Children's Cancer Institute Australia, Uinversity of NSW Sydney, Sydney, New South Wales, Australia
| | - N C Venn
- Children's Cancer Institute Australia, Uinversity of NSW Sydney, Sydney, New South Wales, Australia
| | - M Emerenciano
- Pediatric Hematology-Oncology Program-Research Center, Instituto Nacional de Cancer Rio de Janeiro, Rio de Janeiro, Brazil
| | - M S Pombo-de-Oliveira
- Pediatric Hematology-Oncology Program-Research Center, Instituto Nacional de Cancer Rio de Janeiro, Rio de Janeiro, Brazil
| | - C Barbieri Blunck
- Pediatric Hematology-Oncology Program-Research Center, Instituto Nacional de Cancer Rio de Janeiro, Rio de Janeiro, Brazil
| | - B Almeida Lopes
- Pediatric Hematology-Oncology Program-Research Center, Instituto Nacional de Cancer Rio de Janeiro, Rio de Janeiro, Brazil
| | - J Zuna
- CLIP, Department of Paediatric Haematology/Oncology, Charles University Prague, 2nd Faculty of Medicine, Prague, Czech Republic
| | - J Trka
- CLIP, Department of Paediatric Haematology/Oncology, Charles University Prague, 2nd Faculty of Medicine, Prague, Czech Republic
| | - P Ballerini
- Biological Hematology, AP-HP A. Trousseau, Pierre et Marie Curie University, Paris, France
| | - H Lapillonne
- Biological Hematology, AP-HP A. Trousseau, Pierre et Marie Curie University, Paris, France
| | - M De Braekeleer
- Université de Bretagne Occidentale, Faculté de Médecine et des Sciences de la Santé, Laboratoire d'Histologie, Embryologie et Cytogénétique & INSERM-U1078, Brest, France
| | - G Cazzaniga
- Centro Ricerca Tettamanti, Clinica Pediatrica Univ. Milano Bicocca, Monza, Italy
| | - L Corral Abascal
- Centro Ricerca Tettamanti, Clinica Pediatrica Univ. Milano Bicocca, Monza, Italy
| | | | - E Delabesse
- CHU Purpan, Laboratoire d'Hématologie, Toulouse, France
| | - T S Park
- Department of Laboratory Medicine, School of Medicine, Kyung Hee University, Seoul, Korea
| | - S H Oh
- Department of Laboratory Medicine, Inje University College of Medicine, Busan, Korea
| | - M L M Silva
- Cytogenetics Department, Bone Marrow Transplantation Unit, National Cancer Institute (INCA), Rio de Janeiro, Brazil
| | - T Lund-Aho
- Laboratory of Clinical Genetics, Fimlab Laboratories, Tampere, Finland
| | - V Juvonen
- Department of Clinical Chemistry and TYKSLAB, University of Turku and Turku University Central Hospital, Turku, Finland
| | - A S Moore
- The University of Queensland Diamantina Institute, The University of Queensland, Brisbane, Queensland, Australia
| | - O Heidenreich
- Northern Institute for Cancer Research, Newcastle University, Newcastle upon Tyne, UK
| | - J Vormoor
- The Great North Children's Hospital, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - E Zerkalenkova
- Dmitry Rogachev National Scientific and Practical Center of Pediatric Hematology, Oncology and Immunology, Moscow
| | - Y Olshanskaya
- Dmitry Rogachev National Scientific and Practical Center of Pediatric Hematology, Oncology and Immunology, Moscow
| | - C Bueno
- Josep Carreras Leukemia Research Institute, Department of Biomedicine, School of Medicine, University of Barcelona, Barcelona, Spain.,CIBER de Cancer (CIBERONC), ISCIII, Madrid, Spain.,Institucio Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
| | - P Menendez
- Josep Carreras Leukemia Research Institute, Department of Biomedicine, School of Medicine, University of Barcelona, Barcelona, Spain.,CIBER de Cancer (CIBERONC), ISCIII, Madrid, Spain.,Institucio Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
| | - A Teigler-Schlegel
- Department of Experimental Pathology and Cytology, Institute of Pathology, Giessen, Germany
| | - U Zur Stadt
- Center for Diagnostic, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - J Lentes
- Department of Human Genetics, Hannover Medical School, Hanover, Germany
| | - G Göhring
- Department of Human Genetics, Hannover Medical School, Hanover, Germany
| | - A Kustanovich
- Belarusian Research Center for Pediatric Oncology, Hematology and Immunology, Minsk, Republic of Belarus
| | - O Aleinikova
- Belarusian Research Center for Pediatric Oncology, Hematology and Immunology, Minsk, Republic of Belarus
| | - B W Schäfer
- Department of Oncology, University Children's Hospital Zurich, Zurich, Switzerland
| | - S Kubetzko
- Department of Oncology, University Children's Hospital Zurich, Zurich, Switzerland
| | - H O Madsen
- Department of Clinical Immunology, University Hospital Rigshospitalet, Copenhagen, Denmark
| | - B Gruhn
- Department of Pediatrics, Jena University Hospital, Jena, Germany
| | - X Duarte
- Department of Pediatrics, Portuguese Institute of Oncology of Lisbon, Lisbon, Portugal
| | - P Gameiro
- Hemato-Oncology Laboratory, UIPM, Portuguese Institute of Oncology of Lisbon, Lisbon, Portugal
| | - E Lippert
- Hématologie Biologique, CHU de Brest and INSERM U1078, Université de Bretagne Occidentale, Brest, France
| | - A Bidet
- Hématologie Biologique, CHU de Brest and INSERM U1078, Université de Bretagne Occidentale, Brest, France
| | - J M Cayuela
- Laboratoire d'hématologie, AP-HP Saint-Louis, Paris Diderot University, Paris, France
| | - E Clappier
- Laboratoire d'hématologie, AP-HP Saint-Louis, Paris Diderot University, Paris, France
| | - C N Alonso
- Hospital Nacional de Pediatría Prof Dr J. P. Garrahan, Servcio de Hemato-Oncología, Buenos Aires, Argentina
| | - C M Zwaan
- Department of Pediatric Oncology/Hematology, Erasmus MC, Sophia Children's Hospital, Rotterdam, The Netherlands
| | - M M van den Heuvel-Eibrink
- Department of Pediatric Oncology/Hematology, Erasmus MC, Sophia Children's Hospital, Rotterdam, The Netherlands
| | - S Izraeli
- The Chaim Sheba Medical Center, Department of Pediatric Hemato-Oncology and the Cancer Research Center, Tel Aviv, Israel.,Sackler Medical School Tel Aviv University, Tel Aviv, Israel
| | - L Trakhtenbrot
- The Chaim Sheba Medical Center, Department of Pediatric Hemato-Oncology and the Cancer Research Center, Tel Aviv, Israel.,Sackler Medical School Tel Aviv University, Tel Aviv, Israel
| | - P Archer
- Bristol Genetics Laboratory, Pathology Sciences, Southmead Hospital, North Bristol NHS Trust, Bristol, UK
| | - J Hancock
- Bristol Genetics Laboratory, Pathology Sciences, Southmead Hospital, North Bristol NHS Trust, Bristol, UK
| | - A Möricke
- Department of Pediatrics, University Medical Centre Schleswig-Holstein, Kiel, Germany
| | - J Alten
- Department of Pediatrics, University Medical Centre Schleswig-Holstein, Kiel, Germany
| | - M Schrappe
- Department of Pediatrics, University Medical Centre Schleswig-Holstein, Kiel, Germany
| | - M Stanulla
- Department of Pediatrics, MHH, Hanover, Germany
| | - S Strehl
- Children's Cancer Research Institute and St Anna Children's Hospital, Department of Pediatrics, Medical University of Vienna, Vienna, Austria
| | - A Attarbaschi
- Children's Cancer Research Institute and St Anna Children's Hospital, Department of Pediatrics, Medical University of Vienna, Vienna, Austria
| | - M Dworzak
- Children's Cancer Research Institute and St Anna Children's Hospital, Department of Pediatrics, Medical University of Vienna, Vienna, Austria
| | - O A Haas
- Children's Cancer Research Institute and St Anna Children's Hospital, Department of Pediatrics, Medical University of Vienna, Vienna, Austria
| | - R Panzer-Grümayer
- Children's Cancer Research Institute and St Anna Children's Hospital, Department of Pediatrics, Medical University of Vienna, Vienna, Austria
| | - L Sedék
- Department of Microbiology and Immunology, Medical University of Silesia, Zabrze, Poland
| | - T Szczepański
- Department of Pediatric Hematology and Oncology, Medical University of Silesia, Zabrze, Poland
| | - A Caye
- Department of Genetics, AP-HP Robert Debré, Paris Diderot University, Paris, France
| | - L Suarez
- Department of Genetics, AP-HP Robert Debré, Paris Diderot University, Paris, France
| | - H Cavé
- Department of Genetics, AP-HP Robert Debré, Paris Diderot University, Paris, France
| | - R Marschalek
- Institute of Pharmaceutical Biology/Diagnostic Center of Acute Leukemia (DCAL), Goethe-University, Frankfurt/Main, Germany
| |
Collapse
|
19
|
Pérez-Garrastachu M, Arluzea J, Andrade R, Díez-Torre A, Urtizberea M, Silió M, Aréchaga J. Nucleoporins redistribute inside the nucleus after cell cycle arrest induced by histone deacetylases inhibition. Nucleus 2017; 8:515-533. [PMID: 28696859 DOI: 10.1080/19491034.2017.1320001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Nucleoporins are the main components of the nuclear-pore complex (NPC) and were initially considered as mere structural elements embedded in the nuclear envelope, being responsible for nucleocytoplasmic transport. Nevertheless, several recent scientific reports have revealed that some nucleoporins participate in nuclear processes such as transcription, replication, DNA repair and chromosome segregation. Thus, the interaction of NPCs with chromatin could modulate the distribution of chromosome territories relying on the epigenetic state of DNA. In particular, the nuclear basket proteins Tpr and Nup153, and the FG-nucleoporin Nup98 seem to play key roles in all these novel functions. In this work, histone deacetylase inhibitors (HDACi) were used to induce a hyperacetylated state of chromatin and the behavior of the mentioned nucleoporins was studied. Our results show that, after HDACi treatment, Tpr, Nup153 and Nup98 are translocated from the nuclear pore toward the interior of the cell nucleus, accumulating as intranuclear nucleoporin clusters. These transitory structures are highly dynamic, and are mainly present in the population of cells arrested at the G0/G1 phase of the cell cycle. Our results indicate that the redistribution of these nucleoporins from the nuclear envelope to the nuclear interior may be implicated in the early events of cell cycle initialization, particularly during the G1 phase transition.
Collapse
Affiliation(s)
- Miguel Pérez-Garrastachu
- a Laboratory of Stem Cells, Development & Cancer, Department of Cell Biology and Histology, Faculty of Medicine and Nursing , University of the Basque Country (UPV/EHU) , Leioa , Biscay , Spain
| | - Jon Arluzea
- a Laboratory of Stem Cells, Development & Cancer, Department of Cell Biology and Histology, Faculty of Medicine and Nursing , University of the Basque Country (UPV/EHU) , Leioa , Biscay , Spain.,b High Resolution and Analytical Biomedical Microscopy Core Facility, SGIKer , University of the Basque Country (UPV/EHU) , Leioa , Biscay , Spain
| | - Ricardo Andrade
- b High Resolution and Analytical Biomedical Microscopy Core Facility, SGIKer , University of the Basque Country (UPV/EHU) , Leioa , Biscay , Spain
| | - Alejandro Díez-Torre
- b High Resolution and Analytical Biomedical Microscopy Core Facility, SGIKer , University of the Basque Country (UPV/EHU) , Leioa , Biscay , Spain
| | - Marta Urtizberea
- a Laboratory of Stem Cells, Development & Cancer, Department of Cell Biology and Histology, Faculty of Medicine and Nursing , University of the Basque Country (UPV/EHU) , Leioa , Biscay , Spain
| | - Margarita Silió
- a Laboratory of Stem Cells, Development & Cancer, Department of Cell Biology and Histology, Faculty of Medicine and Nursing , University of the Basque Country (UPV/EHU) , Leioa , Biscay , Spain
| | - Juan Aréchaga
- a Laboratory of Stem Cells, Development & Cancer, Department of Cell Biology and Histology, Faculty of Medicine and Nursing , University of the Basque Country (UPV/EHU) , Leioa , Biscay , Spain.,b High Resolution and Analytical Biomedical Microscopy Core Facility, SGIKer , University of the Basque Country (UPV/EHU) , Leioa , Biscay , Spain
| |
Collapse
|
20
|
Duheron V, Nilles N, Pecenko S, Martinelli V, Fahrenkrog B. Localisation of Nup153 and SENP1 to nuclear pore complexes is required for 53BP1-mediated DNA double-strand break repair. J Cell Sci 2017; 130:2306-2316. [PMID: 28576968 DOI: 10.1242/jcs.198390] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 05/28/2017] [Indexed: 12/28/2022] Open
Abstract
The nuclear basket of nuclear pore complexes (NPCs) is composed of three nucleoporins: Nup153, Nup50 and Tpr. Nup153 has a role in DNA double-strand break (DSB) repair by promoting nuclear import of 53BP1 (also known as TP53BP1), a mediator of the DNA damage response. Here, we provide evidence that loss of Nup153 compromises 53BP1 sumoylation, a prerequisite for efficient accumulation of 53BP1 at DSBs. Depletion of Nup153 resulted in reduced SUMO1 modification of 53BP1 and the displacement of the SUMO protease SENP1 from NPCs. Artificial tethering of SENP1 to NPCs restored non-homologous end joining (NHEJ) in the absence of Nup153 and re-established 53BP1 sumoylation. Furthermore, Nup50 and Tpr, the two other nuclear basket nucleoporins, also contribute to proper DSB repair, in a manner distinct from Nup153. Similar to the role of Nup153, Tpr is implicated in NHEJ and homologous recombination (HR), whereas loss of Nup50 only affects NHEJ. Despite the requirement of all three nucleoporins for accurate NHEJ, only Nup153 is needed for proper nuclear import of 53BP1 and SENP1-dependent sumoylation of 53BP1. Our data support the role of Nup153 as an important regulator of 53BP1 activity and efficient NHEJ.
Collapse
Affiliation(s)
- Vincent Duheron
- Laboratory Biology of the Nucleus, Institute for Molecular Biology and Medicine, Université Libre de Bruxelles, Charleroi 6041, Belgium
| | - Nadine Nilles
- Laboratory Biology of the Nucleus, Institute for Molecular Biology and Medicine, Université Libre de Bruxelles, Charleroi 6041, Belgium
| | - Sylvia Pecenko
- Laboratory Biology of the Nucleus, Institute for Molecular Biology and Medicine, Université Libre de Bruxelles, Charleroi 6041, Belgium
| | - Valérie Martinelli
- Laboratory Biology of the Nucleus, Institute for Molecular Biology and Medicine, Université Libre de Bruxelles, Charleroi 6041, Belgium
| | - Birthe Fahrenkrog
- Laboratory Biology of the Nucleus, Institute for Molecular Biology and Medicine, Université Libre de Bruxelles, Charleroi 6041, Belgium
| |
Collapse
|
21
|
Tuand K, Stijnen P, Volders K, Declercq J, Nuytens K, Meulemans S, Creemers J. Nuclear Localization of the Autism Candidate Gene Neurobeachin and Functional Interaction with the NOTCH1 Intracellular Domain Indicate a Role in Regulating Transcription. PLoS One 2016; 11:e0151954. [PMID: 26999814 PMCID: PMC4801420 DOI: 10.1371/journal.pone.0151954] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Accepted: 03/07/2016] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Neurobeachin (NBEA) is an autism spectrum disorders (ASD) candidate gene. NBEA deficiency affects regulated secretion, receptor trafficking, synaptic architecture and protein kinase A (PKA)-mediated phosphorylation. NBEA is a large multidomain scaffolding protein. From N- to C-terminus, NBEA has a concanavalin A-like lectin domain flanked by armadillo repeats (ACA), an A-kinase anchoring protein domain that can bind to PKA, a domain of unknown function (DUF1088) and a BEACH domain, preceded by a pleckstrin homology-like domain and followed by WD40 repeats (PBW). Although most of these domains mediate protein-protein interactions, no interaction screen has yet been performed. METHODS Yeast two-hybrid screens with the ACA and PBW domain modules of NBEA gave a list of interaction partners, which were analyzed for Gene Ontology (GO) enrichment. Neuro-2a cells were used for confocal microscopy and nuclear extraction analysis. NOTCH-mediated transcription was studied with luciferase reporter assays and qRT-PCR, combined with NBEA knockdown or overexpression. RESULTS Both domain modules showed a GO enrichment for the nucleus. PBW almost exclusively interacted with transcription regulators, while ACA interacted with a number of PKA substrates. NBEA was partially localized in the nucleus of Neuro-2a cells, albeit much less than in the cytoplasm. A nuclear localization signal was found in the DUF1088 domain, which was shown to contribute to the nuclear localization of an EGFP-DPBW fusion protein. Yeast two-hybrid identified the Notch1 intracellular domain as a physical interactor of the PBW domain and a role for NBEA as a negative regulator in Notch-mediated transcription was demonstrated. CONCLUSION Defining novel interaction partners of conserved NBEA domain modules identified a role for NBEA as transcriptional regulator in the nucleus. The physical interaction of NBEA with NOTCH1 is most relevant for ASD pathogenesis because NOTCH signaling is essential for neural development.
Collapse
Affiliation(s)
- Krizia Tuand
- Department of Human Genetics, KU Leuven, Leuven, Belgium
- Leuven Autism Research consortium (LAuRes), KU Leuven, Leuven, Belgium
| | - Pieter Stijnen
- Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Karolien Volders
- Department of Human Genetics, KU Leuven, Leuven, Belgium
- Leuven Autism Research consortium (LAuRes), KU Leuven, Leuven, Belgium
| | | | - Kim Nuytens
- Department of Human Genetics, KU Leuven, Leuven, Belgium
- Leuven Autism Research consortium (LAuRes), KU Leuven, Leuven, Belgium
| | | | - John Creemers
- Department of Human Genetics, KU Leuven, Leuven, Belgium
- * E-mail:
| |
Collapse
|
22
|
Popken J, Schmid VJ, Strauss A, Guengoer T, Wolf E, Zakhartchenko V. Stage-dependent remodeling of the nuclear envelope and lamina during rabbit early embryonic development. J Reprod Dev 2015; 62:127-35. [PMID: 26640117 PMCID: PMC4848569 DOI: 10.1262/jrd.2015-100] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Utilizing 3D structured illumination microscopy, we investigated the quality and quantity of nuclear
invaginations and the distribution of nuclear pores during rabbit early embryonic development and identified
the exact time point of nucleoporin 153 (NUP153) association with chromatin during mitosis. Contrary to bovine
early embryonic nuclei, featuring almost exclusively nuclear invaginations containing a small volume of
cytoplasm, nuclei in rabbit early embryonic stages show additionally numerous invaginations containing a large
volume of cytoplasm. Small-volume invaginations frequently emanated from large-volume nuclear invaginations
but not vice versa, indicating a different underlying mechanism. Large- and small-volume
nuclear envelope invaginations required the presence of chromatin, as they were restricted to
chromatin-positive areas. The chromatin-free contact areas between nucleolar precursor bodies (NPBs) and
large-volume invaginations were free of nuclear pores. Small-volume invaginations were not in contact with
NPBs. The number of invaginations and isolated intranuclear vesicles per nucleus peaked at the 4-cell stage.
At this stage, the nuclear surface showed highly concentrated clusters of nuclear pores surrounded by areas
free of nuclear pores. Isolated intranuclear lamina vesicles were usually NUP153 negative. Cytoplasmic,
randomly distributed NUP153-positive clusters were highly abundant at the zygote stage and decreased in number
until they were almost absent at the 8-cell stage and later. These large NUP153 clusters may represent a
maternally provided NUP153 deposit, but they were not visible as clusters during mitosis. Major genome
activation at the 8- to 16-cell stage may mark the switch from a necessity for a deposit to on-demand
production. NUP153 association with chromatin is initiated during metaphase before the initiation of the
regeneration of the lamina. To our knowledge, the present study demonstrates for the first time major
remodeling of the nuclear envelope and its underlying lamina during rabbit preimplantation development.
Collapse
Affiliation(s)
- Jens Popken
- Division of Anthropology and Human Genetics, Biocenter, LMU Munich, D-82152 Planegg-Martinsried, Germany
| | | | | | | | | | | |
Collapse
|
23
|
Schwartz M, Travesa A, Martell SW, Forbes DJ. Analysis of the initiation of nuclear pore assembly by ectopically targeting nucleoporins to chromatin. Nucleus 2015; 6:40-54. [PMID: 25602437 PMCID: PMC4615246 DOI: 10.1080/19491034.2015.1004260] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
Nuclear pore complexes (NPCs) form the gateway to the nucleus, mediating virtually all nucleocytoplasmic trafficking. Assembly of a nuclear pore complex requires the organization of many soluble sub-complexes into a final massive structure embedded in the nuclear envelope. By use of a LacI/LacO reporter system, we were able to assess nucleoporin (Nup) interactions, show that they occur with a high level of specificity, and identify nucleoporins sufficient for initiation of the complex process of NPC assembly in vivo. Eleven nucleoporins from different sub-complexes were fused to LacI-CFP and transfected separately into a human cell line containing a stably integrated LacO DNA array. The LacI-Nup fusion proteins, which bound to the array, were examined for their ability to recruit endogenous nucleoporins to the intranuclear LacO site. Many could recruit nucleoporins of the same sub-complex and a number could also recruit other sub-complexes. Strikingly, Nup133 and Nup107 of the Nup107/160 subcomplex and Nup153 and Nup50 of the nuclear pore basket recruited a near full complement of nucleoporins to the LacO array. Furthermore, Nup133 and Nup153 efficiently targeted the LacO array to the nuclear periphery. Our data support a hierarchical, seeded assembly pathway and identify Nup133 and Nup153 as effective “seeds” for NPC assembly. In addition, we show that this system can be applied to functional studies of individual nucleoporin domains as well as to specific nucleoporin disease mutations. We find that the R391H cardiac arrhythmia/sudden death mutation of Nup155 prevents both its subcomplex assembly and nuclear rim targeting of the LacO array.
Collapse
Affiliation(s)
- Michal Schwartz
- a Section of Cell and Developmental Biology; Division of Biological Sciences 0347; University of California-San Diego ; La Jolla , CA USA
| | | | | | | |
Collapse
|
24
|
Bin Hamid F, Kim J, Shin CG. Cellular and viral determinants of retroviral nuclear entry. Can J Microbiol 2015; 62:1-15. [PMID: 26553381 DOI: 10.1139/cjm-2015-0350] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Retroviruses must integrate their cDNA into the host genome to generate proviruses. Viral DNA-protein complexes interact with cellular proteins and produce pre-integration complexes, which carry the viral genome and cross the nuclear pore channel to enter the nucleus and integrate viral DNA into host chromosomal DNA. If the reverse transcripts fail to integrate, linear or circular DNA species such as 1- and 2-long terminal repeats are generated. Such complexes encounter numerous cellular proteins in the cytoplasm, which restrict viral infection and protect the nucleus. To overcome host cell defenses, the pathogens have evolved several evasion strategies. Viral proteins often contain nuclear localization signals, allowing entry into the nucleus. Among more than 1000 proteins identified as required for HIV infection by RNA interference screening, karyopherins, cleavage and polyadenylation specific factor 6, and nucleoporins have been predominantly studied. This review discusses current opinions about the synergistic relationship between the viral and cellular factors involved in nuclear import, with focus on the unveiled mysteries of the host-pathogen interaction, and highlights novel approaches to pinpoint therapeutic targets.
Collapse
Affiliation(s)
- Faysal Bin Hamid
- Department of Systems Biotechnology, Chung-Ang University, Ansung 456-756, Republic of Korea.,Department of Systems Biotechnology, Chung-Ang University, Ansung 456-756, Republic of Korea
| | - Jinsun Kim
- Department of Systems Biotechnology, Chung-Ang University, Ansung 456-756, Republic of Korea.,Department of Systems Biotechnology, Chung-Ang University, Ansung 456-756, Republic of Korea
| | - Cha-Gyun Shin
- Department of Systems Biotechnology, Chung-Ang University, Ansung 456-756, Republic of Korea.,Department of Systems Biotechnology, Chung-Ang University, Ansung 456-756, Republic of Korea
| |
Collapse
|
25
|
Dickmanns A, Kehlenbach RH, Fahrenkrog B. Nuclear Pore Complexes and Nucleocytoplasmic Transport: From Structure to Function to Disease. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2015; 320:171-233. [PMID: 26614874 DOI: 10.1016/bs.ircmb.2015.07.010] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Nucleocytoplasmic transport is an essential cellular activity and occurs via nuclear pore complexes (NPCs) that reside in the double membrane of the nuclear envelope. Significant progress has been made during the past few years in unravelling the ultrastructural organization of NPCs and their constituents, the nucleoporins, by cryo-electron tomography and X-ray crystallography. Mass spectrometry and genomic approaches have provided deeper insight into the specific regulation and fine tuning of individual nuclear transport pathways. Recent research has also focused on the roles nucleoporins play in health and disease, some of which go beyond nucleocytoplasmic transport. Here we review emerging results aimed at understanding NPC architecture and nucleocytoplasmic transport at the atomic level, elucidating the specific function individual nucleoporins play in nuclear trafficking, and finally lighting up the contribution of nucleoporins and nuclear transport receptors in human diseases, such as cancer and certain genetic disorders.
Collapse
Affiliation(s)
- Achim Dickmanns
- Abteilung für Molekulare Strukturbiologie, Institut für Mikrobiologie und Genetik, Göttinger Zentrum für Molekulare Biowissenschaften, Georg-August-Universität Göttingen, Göttingen, Germany
| | - Ralph H Kehlenbach
- Department of Molecular Biology, Faculty of Medicine, Georg-August-University of Göttingen, Göttingen, Germany
| | - Birthe Fahrenkrog
- Institute of Molecular Biology and Medicine, Université Libre de Bruxelles, Charleroi, Belgium
| |
Collapse
|
26
|
Nup153 Recruits the Nup107-160 Complex to the Inner Nuclear Membrane for Interphasic Nuclear Pore Complex Assembly. Dev Cell 2015; 33:717-28. [DOI: 10.1016/j.devcel.2015.04.027] [Citation(s) in RCA: 106] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Revised: 02/27/2015] [Accepted: 04/28/2015] [Indexed: 11/20/2022]
|
27
|
Popken J, Graf A, Krebs S, Blum H, Schmid VJ, Strauss A, Guengoer T, Zakhartchenko V, Wolf E, Cremer T. Remodeling of the Nuclear Envelope and Lamina during Bovine Preimplantation Development and Its Functional Implications. PLoS One 2015; 10:e0124619. [PMID: 25932910 PMCID: PMC4416817 DOI: 10.1371/journal.pone.0124619] [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: 08/12/2014] [Accepted: 03/17/2015] [Indexed: 11/19/2022] Open
Abstract
The present study demonstrates a major remodeling of the nuclear envelope and its underlying lamina during bovine preimplantation development. Up to the onset of major embryonic genome activation (MGA) at the 8-cell stage nuclei showed a non-uniform distribution of nuclear pore complexes (NPCs). NPCs were exclusively present at sites where DNA contacted the nuclear lamina. Extended regions of the lamina, which were not contacted by DNA, lacked NPCs. In post-MGA nuclei the whole lamina was contacted rather uniformly by DNA. Accordingly, NPCs became uniformly distributed throughout the entire nuclear envelope. These findings shed new light on the conditions which control the integration of NPCs into the nuclear envelope. The switch from maternal to embryonic production of mRNAs was accompanied by multiple invaginations covered with NPCs, which may serve the increased demands of mRNA export and protein import. Other invaginations, as well as interior nuclear segments and vesicles without contact to the nuclear envelope, were exclusively positive for lamin B. Since the abundance of these invaginations and vesicles increased in concert with a massive nuclear volume reduction, we suggest that they reflect a mechanism for fitting the nuclear envelope and its lamina to a shrinking nuclear size during bovine preimplantation development. In addition, a deposit of extranuclear clusters of NUP153 (a marker for NPCs) without associated lamin B was frequently observed from the zygote stage up to MGA. Corresponding RNA-Seq data revealed deposits of spliced, maternally provided NUP153 mRNA and little unspliced, newly synthesized RNA prior to MGA, which increased strongly at the initiation of embryonic expression of NUP153 at MGA.
Collapse
Affiliation(s)
- Jens Popken
- Division of Anthropology and Human Genetics, Biocenter, LMU Munich, Planegg-Martinsried, Germany
- Chair for Molecular Animal Breeding and Biotechnology, Gene Center, LMU Munich, Munich, Germany
- * E-mail: (JP); (EW); (TC)
| | - Alexander Graf
- Laboratory for Functional Genome Analysis (LAFUGA), Gene Center, LMU Munich, Munich, Germany
| | - Stefan Krebs
- Laboratory for Functional Genome Analysis (LAFUGA), Gene Center, LMU Munich, Munich, Germany
| | - Helmut Blum
- Laboratory for Functional Genome Analysis (LAFUGA), Gene Center, LMU Munich, Munich, Germany
| | | | - Axel Strauss
- Division of Genetics, Biocenter, LMU Munich, Planegg-Martinsried, Germany
| | - Tuna Guengoer
- Chair for Molecular Animal Breeding and Biotechnology, Gene Center, LMU Munich, Munich, Germany
| | - Valeri Zakhartchenko
- Chair for Molecular Animal Breeding and Biotechnology, Gene Center, LMU Munich, Munich, Germany
| | - Eckhard Wolf
- Chair for Molecular Animal Breeding and Biotechnology, Gene Center, LMU Munich, Munich, Germany
- Laboratory for Functional Genome Analysis (LAFUGA), Gene Center, LMU Munich, Munich, Germany
- * E-mail: (JP); (EW); (TC)
| | - Thomas Cremer
- Division of Anthropology and Human Genetics, Biocenter, LMU Munich, Planegg-Martinsried, Germany
- * E-mail: (JP); (EW); (TC)
| |
Collapse
|
28
|
Influenza virus-induced caspase-dependent enlargement of nuclear pores promotes nuclear export of viral ribonucleoprotein complexes. J Virol 2015; 89:6009-21. [PMID: 25810542 DOI: 10.1128/jvi.03531-14] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 03/17/2015] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Influenza A viruses (IAV) replicate their segmented RNA genome in the nucleus of infected cells and utilize caspase-dependent nucleocytoplasmic export mechanisms to transport newly formed ribonucleoprotein complexes (RNPs) to the site of infectious virion release at the plasma membrane. In this study, we obtained evidence that apoptotic caspase activation in IAV-infected cells is associated with the degradation of the nucleoporin Nup153, an integral subunit of the nuclear pore complex. Transmission electron microscopy studies revealed a distinct enlargement of nuclear pores in IAV-infected cells. Transient expression and subcellular accumulation studies of multimeric marker proteins in virus-infected cells provided additional evidence for increased nuclear pore diameters facilitating the translocation of large protein complexes across the nuclear membrane. Furthermore, caspase 3/7 inhibition data obtained in this study suggest that active, Crm1-dependent IAV RNP export mechanisms are increasingly complemented by passive, caspase-induced export mechanisms at later stages of infection. IMPORTANCE In contrast to the process seen with most other RNA viruses, influenza virus genome replication occurs in the nucleus (rather than the cytoplasm) of infected cells. Therefore, completion of the viral replication cycle critically depends on intracellular transport mechanisms that ensure the translocation of viral ribonucleoprotein (RNP) complexes across the nuclear membrane. Here, we demonstrate that virus-induced cellular caspase activities cause a widening of nuclear pores, thereby facilitating nucleocytoplasmic translocation processes and, possibly, promoting nuclear export of newly synthesized RNPs. These passive transport mechanisms are suggested to complement Crm1-dependent RNP export mechanisms known to occur at early stages of the replication cycle and may contribute to highly efficient production of infectious virus progeny at late stages of the viral replication cycle. The report provides an intriguing example of how influenza virus exploits cellular structures and regulatory pathways, including intracellular transport mechanisms, to complete its replication cycle and maximize the production of infectious virus progeny.
Collapse
|
29
|
Lowe AR, Tang JH, Yassif J, Graf M, Huang WYC, Groves JT, Weis K, Liphardt JT. Importin-β modulates the permeability of the nuclear pore complex in a Ran-dependent manner. eLife 2015; 4. [PMID: 25748139 PMCID: PMC4375889 DOI: 10.7554/elife.04052] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Accepted: 02/27/2015] [Indexed: 11/13/2022] Open
Abstract
Soluble karyopherins of the importin-β (impβ) family use RanGTP to transport cargos directionally through the nuclear pore complex (NPC). Whether impβ or RanGTP regulate the permeability of the NPC itself has been unknown. In this study, we identify a stable pool of impβ at the NPC. A subpopulation of this pool is rapidly turned-over by RanGTP, likely at Nup153. Impβ, but not transportin-1 (TRN1), alters the pore's permeability in a Ran-dependent manner, suggesting that impβ is a functional component of the NPC. Upon reduction of Nup153 levels, inert cargos more readily equilibrate across the NPC yet active transport is impaired. When purified impβ or TRN1 are mixed with Nup153 in vitro, higher-order, multivalent complexes form. RanGTP dissolves the impβ•Nup153 complexes but not those of TRN1•Nup153. We propose that impβ and Nup153 interact at the NPC's nuclear face to form a Ran-regulated mesh that modulates NPC permeability. DOI:http://dx.doi.org/10.7554/eLife.04052.001 In our cells, genetic material is contained within the nucleus, which is separated from the rest of the cell by a double-layered membrane called the nuclear envelope. Within this membrane there are pores that allow proteins and other molecules to enter and exit the nucleus. Small molecules can pass through these pores unaided, which is known as ‘passive’ transport. However, larger cargos need help from transport receptor proteins in a process called ‘active’ transport. Large cargos bind to transport receptors, such as importin-β, in the cytoplasm and are then guided through the pore. Once the cargo and importin-β are inside the nucleus, a protein called RanGTP binds to importin-β to release the cargo. It is thought that importin-β and RanGTP are only important for the active transport of cargo. Here, Lowe et al. studied how importin-β interacts with the pore. The experiments show that in the absence of RanGTP, importin-β accumulates inside the pore and binds to a protein called Nup153, which is part of the complex of proteins that makes up the pore. However, when RanGTP is present, some of the importin-β is displaced from Nup153 and leaves the pore, which makes it easier for cargo to pass through. Further experiments show that when Nup153 and importin-β are mixed, they associate into a gel-like material that can be ‘melted’ by RanGTP. Lowe et al. propose a model for how RanGTP may control the flow of cargo through the nuclear pore by affecting the binding of importin-β to Nup153. Lowe et al.'s findings suggest that passive and active transport of cargo across the nuclear pore are fundamentally connected and suggest that RanGTP provides the cell with an additional layer of control over nucleocytoplasmic transport. DOI:http://dx.doi.org/10.7554/eLife.04052.002
Collapse
Affiliation(s)
- Alan R Lowe
- Institute for Structural and Molecular Biology, University College London and Birkbeck College, London, United Kingdom
| | - Jeffrey H Tang
- Department of Physics, University of California, Berkeley, Berkeley, United States
| | - Jaime Yassif
- Department of Physics, University of California, Berkeley, Berkeley, United States
| | - Michael Graf
- Section of Life Sciences and Technologies, École polytechnique fédérale de Lausanne, Lausanne, Switzerland
| | - William Y C Huang
- Department of Chemistry, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, United States
| | - Jay T Groves
- QB3, University of California, Berkeley, Berkeley, United States
| | - Karsten Weis
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Jan T Liphardt
- Department of Physics, University of California, Berkeley, Berkeley, United States
| |
Collapse
|
30
|
Chromatin organization at the nuclear pore favours HIV replication. Nat Commun 2015; 6:6483. [PMID: 25744187 PMCID: PMC4366494 DOI: 10.1038/ncomms7483] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Accepted: 02/02/2015] [Indexed: 11/08/2022] Open
Abstract
The molecular mechanisms that allow HIV to integrate into particular sites of the host genome are poorly understood. Here we tested if the nuclear pore complex (NPC) facilitates the targeting of HIV integration by acting on chromatin topology. We show that the integrity of the nuclear side of the NPC, which is mainly composed of Tpr, is not required for HIV nuclear import, but that Nup153 is essential. Depletion of Tpr markedly reduces HIV infectivity, but not the level of integration. HIV integration sites in Tpr-depleted cells are less associated with marks of active genes, consistent with the state of chromatin proximal to the NPC, as analysed by super-resolution microscopy. LEDGF/p75, which promotes viral integration into active genes, stabilizes Tpr at the nuclear periphery and vice versa. Our data support a model in which HIV nuclear import and integration are concerted steps, and where Tpr maintains a chromatin environment favourable for HIV replication.
Collapse
|
31
|
Milles S, Lemke EA. Mapping Multivalency and Differential Affinities within Large Intrinsically Disordered Protein Complexes with Segmental Motion Analysis. Angew Chem Int Ed Engl 2014; 53:7364-7. [DOI: 10.1002/anie.201403694] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Indexed: 11/10/2022]
Affiliation(s)
- Sigrid Milles
- Structural and Computational Biology Unit, EMBL, Meyerhofstrasse 1, 69117 Heidelberg (Germany)
| | - Edward A. Lemke
- Structural and Computational Biology Unit, EMBL, Meyerhofstrasse 1, 69117 Heidelberg (Germany)
| |
Collapse
|
32
|
Milles S, Lemke EA. Detektion von Mehrbindigkeit und differenziellen Affinitäten in großen, intrinsisch ungeordneten Proteinen mithilfe von Segmentbewegungsanalyse. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201403694] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Sigrid Milles
- Structural and Computational Biology Unit, EMBL, Meyerhofstraße 1, 69117 Heidelberg (Deutschland)
| | - Edward A. Lemke
- Structural and Computational Biology Unit, EMBL, Meyerhofstraße 1, 69117 Heidelberg (Deutschland)
| |
Collapse
|
33
|
Differential functions of calpain 1 during epithelial cell death and adipocyte differentiation in mammary gland involution. Biochem J 2014; 459:355-68. [PMID: 24467364 DOI: 10.1042/bj20130847] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Calpains become activated in the mammary gland early during weaning, cleaving several proteins located mainly in the cell membrane, but also in other organelles such as lysosomes, mitochondria and nuclei. By immunofluorescence and Western blot analysis, we have demonstrated the nuclear translocation of calpain-1 and calpain-2, together with the cleavage of several cytoplasmic nucleoporins in epithelial cells of the lobulo-alveolar compartment. In vivo and in vitro calpain inhibition prevented this nucleoporin degradation. In addition, calpain-1 was also present in the nucleus of non-epithelial mammary tissue cells, concomitant with adipocyte re-differentiation. Calpain-1 was internalized within nuclei and found to be present in the nuclear chromatin-enriched fraction, associated with histone H3. Furthermore, we have demonstrated, both in vivo and in vitro, the cleavage of the N-terminal residue of histone H3 by calpain-1. Calpain-1 co-localized with both H3K4me3 (histone H3 trimethylated at Lys4) and H3K27me3 (histone H3 trimethylated at Lys27) at the nuclear periphery, a bivalent epigenetic signal essential for cell differentiation. Using ChIP assays we could confirm the presence of calpain-1 in the promoters of key genes expressed in adipose tissue, such as Cebpa (CCAAT/enhancer-binding protein α) and Lep (leptin). The results of the present study highlight a dual role for calpain-1 in the weaned gland after the pregnancy/lactation cycle, controlling programmed cell death and participating in the epigenetic programme during adipocyte differentiation.
Collapse
|
34
|
|
35
|
Onder Z, Moroianu J. Nuclear import of cutaneous beta genus HPV8 E7 oncoprotein is mediated by hydrophobic interactions between its zinc-binding domain and FG nucleoporins. Virology 2013; 449:150-62. [PMID: 24418548 DOI: 10.1016/j.virol.2013.11.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 10/08/2013] [Accepted: 11/11/2013] [Indexed: 10/25/2022]
Abstract
We have previously discovered and characterized the nuclear import pathways for the E7 oncoproteins of mucosal alpha genus HPVs, type 16 and 11. Here we investigated the nuclear import of cutaneous beta genus HPV8 E7 protein using confocal microscopy after transfections of HeLa cells with EGFP-8E7 and mutant plasmids and nuclear import assays in digitonin-permeabilized HeLa cells. We determined that HPV8 E7 contains a nuclear localization signal (NLS) within its zinc-binding domain that mediates its nuclear import. Furthermore, we discovered that a mostly hydrophobic patch 65LRLFV69 within the zinc-binding domain is essential for the nuclear import and localization of HPV8 E7 via hydrophobic interactions with the FG nucleoporins Nup62 and Nup153. Substitution of the hydrophobic residues within the 65LRLFV69 patch to alanines, and not R66A mutation, disrupt the interactions between the 8E7 zinc-binding domain and Nup62 and Nup153 and consequently inhibit nuclear import of HPV8 E7.
Collapse
Affiliation(s)
- Zeynep Onder
- Biology Department, Boston College, Chestnut Hill, MA 02467, USA
| | - Junona Moroianu
- Biology Department, Boston College, Chestnut Hill, MA 02467, USA.
| |
Collapse
|
36
|
New insights in the role of nucleoporins: a bridge leading to concerted steps from HIV-1 nuclear entry until integration. Virus Res 2013; 178:187-96. [PMID: 24051001 DOI: 10.1016/j.virusres.2013.09.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Revised: 09/01/2013] [Accepted: 09/02/2013] [Indexed: 11/22/2022]
Abstract
Human Immunodeficiency virus type 1 (HIV-1), as well as many other viruses that depend on nuclear entry for replication, has developed an evolutionary strategy to dock and translocate through the nuclear pore complex (NPC). In particular, the nuclear pore is not a static window but it is a dynamic structure involved in many vital cellular functions, as nuclear import/export, gene regulation, chromatin organization and genome stability. This review aims to shed light on viral mechanisms developed by HIV-1 to usurp cellular machinery to favor viral gene expression and their replication. In particular, it will be reviewed both what is known and what is speculated about the link between HIV translocation through the nuclear pore and the proviral integration in the host chromatin.
Collapse
|
37
|
Hahm JB, Privalsky ML. Research resource: identification of novel coregulators specific for thyroid hormone receptor-β2. Mol Endocrinol 2013; 27:840-59. [PMID: 23558175 DOI: 10.1210/me.2012-1117] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Thyroid hormone receptors (TRs) are expressed as a series of interrelated isoforms that perform distinct biological roles. The TRβ2 isoform is found predominantly in the hypothalamus, pituitary, retina, and cochlea and displays unique transcriptional properties relative to the other TR isoforms. To more fully understand the isoform-specific biological and molecular properties of TRβ2, we have identified a series of previously unrecognized proteins that selectively interact with TRβ2 compared with the more widely expressed TRβ1. Several of these proteins preferentially enhance the transcriptional activity of TRβ2 when coexpressed in cells and are likely to represent novel, isoform-specific coactivators. Additional proteins were also identified in our screen that bind equally to TRβ1 and TRβ2 and may function as isoform-independent auxiliary proteins for these and/or other nuclear receptors. We propose that a combination of isoform-specific recruitment and tissue-specific expression of these newly identified coregulator candidates serves to customize TR function for different biological purposes in different cell types.
Collapse
Affiliation(s)
- Johnnie B Hahm
- Department of Microbiology, University of California at Davis, Davis, CA 95616, USA
| | | |
Collapse
|
38
|
Imberg-Kazdan K, Ha S, Greenfield A, Poultney CS, Bonneau R, Logan SK, Garabedian MJ. A genome-wide RNA interference screen identifies new regulators of androgen receptor function in prostate cancer cells. Genome Res 2013; 23:581-91. [PMID: 23403032 PMCID: PMC3613576 DOI: 10.1101/gr.144774.112] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Accepted: 01/31/2013] [Indexed: 01/22/2023]
Abstract
The androgen receptor (AR) is a mediator of both androgen-dependent and castration-resistant prostate cancers. Identification of cellular factors affecting AR transcriptional activity could in principle yield new targets that reduce AR activity and combat prostate cancer, yet a comprehensive analysis of the genes required for AR-dependent transcriptional activity has not been determined. Using an unbiased genetic approach that takes advantage of the evolutionary conservation of AR signaling, we have conducted a genome-wide RNAi screen in Drosophila cells for genes required for AR transcriptional activity and applied the results to human prostate cancer cells. We identified 45 AR-regulators, which include known pathway components and genes with functions not previously linked to AR regulation, such as HIPK2 (a protein kinase) and MED19 (a subunit of the Mediator complex). Depletion of HIPK2 and MED19 in human prostate cancer cells decreased AR target gene expression and, importantly, reduced the proliferation of androgen-dependent and castration-resistant prostate cancer cells. We also systematically analyzed additional Mediator subunits and uncovered a small subset of Mediator subunits that interpret AR signaling and affect AR-dependent transcription and prostate cancer cell proliferation. Importantly, targeting of HIPK2 by an FDA-approved kinase inhibitor phenocopied the effect of depletion by RNAi and reduced the growth of AR-positive, but not AR-negative, treatment-resistant prostate cancer cells. Thus, our screen has yielded new AR regulators including drugable targets that reduce the proliferation of castration-resistant prostate cancer cells.
Collapse
Affiliation(s)
- Keren Imberg-Kazdan
- Department of Biochemistry and Department of Molecular Pharmacology, New York University School of Medicine, New York, New York 10016, USA
| | - Susan Ha
- Department of Biochemistry and Department of Molecular Pharmacology, New York University School of Medicine, New York, New York 10016, USA
- Department of Urology, New York University School of Medicine, New York, New York 10016, USA
| | - Alex Greenfield
- Center for Genomics and Systems Biology, New York University, New York, New York 10003, USA
| | | | - Richard Bonneau
- Center for Genomics and Systems Biology, New York University, New York, New York 10003, USA
| | - Susan K. Logan
- Department of Biochemistry and Department of Molecular Pharmacology, New York University School of Medicine, New York, New York 10016, USA
- Department of Urology, New York University School of Medicine, New York, New York 10016, USA
- NYU Cancer Institute, New York University School of Medicine, New York, New York 10016, USA
| | - Michael J. Garabedian
- Department of Urology, New York University School of Medicine, New York, New York 10016, USA
- Center for Genomics and Systems Biology, New York University, New York, New York 10003, USA
- NYU Cancer Institute, New York University School of Medicine, New York, New York 10016, USA
- Department of Microbiology, New York University School of Medicine, New York, New York 10016, USA
| |
Collapse
|
39
|
Nup153 and Nup98 bind the HIV-1 core and contribute to the early steps of HIV-1 replication. Virology 2013; 440:8-18. [PMID: 23523133 DOI: 10.1016/j.virol.2013.02.008] [Citation(s) in RCA: 115] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Revised: 01/31/2013] [Accepted: 02/02/2013] [Indexed: 12/13/2022]
Abstract
The early steps of HIV-1 replication involve the entry of HIV-1 into the nucleus, which is characterized by viral interactions with nuclear pore components. HIV-1 developed an evolutionary strategy to usurp the nuclear pore machinery and chromatin in order to integrate and efficiently express viral genes. In the current work, we studied the role of nucleoporins 153 and 98 (Nup153 and Nup98) in infection of human Jurkat lymphocytes by HIV-1. We showed that Nup153-depleted cells exhibited a defect in nuclear import, while depletion of Nup 98 caused a slight defect in HIV integration. To explore the biochemical viral determinants for the requirement of Nup153 and Nup98 during HIV-1 infection, we tested the ability of these nucleoporins to interact with HIV-1 cores. Our findings showed that both nucleoporins bind HIV-1 cores suggesting that this interaction is important for HIV-1 nuclear import and/or integration. Distribution analysis of integration sites in Nup153-depleted cells revealed a reduced tendency of HIV-1 to integrate in intragenic sites, which in part could account for the large infectivity defect observed in Nup153-depleted cells. Our work strongly supports a role for Nup153 in HIV-1 nuclear import and integration.
Collapse
|
40
|
Makise M, Mackay DR, Elgort S, Shankaran SS, Adam SA, Ullman KS. The Nup153-Nup50 protein interface and its role in nuclear import. J Biol Chem 2012; 287:38515-22. [PMID: 23007389 DOI: 10.1074/jbc.m112.378893] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Interactions between Nup50 and soluble transport factors underlie the efficiency of certain nucleocytoplasmic transport pathways. The platform on which these interactions take place is important to building a complete understanding of nucleocytoplasmic trafficking. Nup153 is the nucleoporin that provides this scaffold for Nup50. Here, we have delineated requirements for the interaction between Nup153 and Nup50, revealing a dual interface. An interaction between Nup50 and a region in the unique N-terminal region of Nup153 is critical for the nuclear pore localization of Nup50. A second site of interaction is at the distal tail of Nup153 and is dependent on importin α. Both of these interactions involve the N-terminal domain of Nup50. The configuration of the Nup153-Nup50 partnership suggests that the Nup153 scaffold provides not just a means of pore targeting for Nup50 but also serves to provide a local environment that facilitates bringing Nup50 and importin α together, as well as other soluble factors involved in transport. Consistent with this, disruption of the Nup153-Nup50 interface decreases efficiency of nuclear import.
Collapse
Affiliation(s)
- Masaki Makise
- Department of Oncological Sciences, University of Utah, Salt Lake City, Utah 84112, USA
| | | | | | | | | | | |
Collapse
|
41
|
Iliuk A, Liu XS, Xue L, Liu X, Tao WA. Chemical visualization of phosphoproteomes on membrane. Mol Cell Proteomics 2012; 11:629-39. [PMID: 22593177 PMCID: PMC3434771 DOI: 10.1074/mcp.o112.018010] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2012] [Revised: 05/10/2012] [Indexed: 11/06/2022] Open
Abstract
With new discoveries of important roles of phosphorylation on a daily basis, phospho-specific antibodies, as the primary tool for on-membrane detection of phosphoproteins, face enormous challenges. To address an urgent need for convenient and reliable analysis of phosphorylation events, we report a novel strategy for sensitive phosphorylation analysis in the Western blotting format. The chemical reagent, which we termed pIMAGO, is based on a multifunctionalized soluble nanopolymer and is capable of selectively binding to phosphorylated residues independent of amino acid microenvironment, thus offering great promise as a universal tool in biological analyses where the site of phosphorylation is not known or its specific antibody is not available. The specificity and sensitivity of the approach was first examined using a mixture of standard proteins. The method was then applied to monitor phosphorylation changes in in vitro kinase and phosphatase assays. Finally, to demonstrate the unique ability of pIMAGO to measure endogenous phosphorylation, we used it to visualize and determine the differences in phosphorylated proteins that interact with wild-type and kinase dead mutant of Polo-like kinase 1 during mitosis, the results of which were further confirmed by a quantitative phosphoproteomics experiment.
Collapse
Affiliation(s)
- Anton Iliuk
- From the Department of Biochemistry and Purdue Center for Cancer Research, Purdue University, West Lafayette, Indiana 47907
| | - X. Shawn Liu
- From the Department of Biochemistry and Purdue Center for Cancer Research, Purdue University, West Lafayette, Indiana 47907
| | - Liang Xue
- From the Department of Biochemistry and Purdue Center for Cancer Research, Purdue University, West Lafayette, Indiana 47907
| | - Xiaoqi Liu
- From the Department of Biochemistry and Purdue Center for Cancer Research, Purdue University, West Lafayette, Indiana 47907
| | - W. Andy Tao
- From the Department of Biochemistry and Purdue Center for Cancer Research, Purdue University, West Lafayette, Indiana 47907
| |
Collapse
|
42
|
Woodward CL, Chow SA. The nuclear pore complex: a new dynamic in HIV-1 replication. Nucleus 2012; 1:18-22. [PMID: 21327100 DOI: 10.4161/nucl.1.1.10571] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2009] [Revised: 11/07/2009] [Accepted: 11/10/2009] [Indexed: 01/08/2023] Open
Abstract
The ability to traverse an intact nuclear envelope and productively infect non-dividing cells is a salient feature of human immunodeficiency virus type 1 (HIV-1) and other lentiviruses, but the viral factors and mechanism of nuclear entry have not been defined. We have recently reported a functional role for the nucleoporin NUP153 in the nuclear import of the HIV-1 preintegration complex (PIC). Our findings suggest that HIV-1 sub-viral particles gain access to the nucleus by interacting directly with the nuclear pore complex (NPC) via the binding of PIC-associated integrase (IN) to the C-terminal domain of NUP153. This article discusses how NPC conformation and constitution might influence nuclear import of the PIC, and the subsequent integration of the viral cDNA into actively transcribed genes.
Collapse
Affiliation(s)
- Cora L Woodward
- Department of Molecular and Medical Pharmacology, and UCLA AIDS Institute, UCLA School of Medicine, Los Angeles, CA, USA
| | | |
Collapse
|
43
|
Lussi YC, Shumaker DK, Shimi T, Fahrenkrog B. The nucleoporin Nup153 affects spindle checkpoint activity due to an association with Mad1. Nucleus 2012; 1:71-84. [PMID: 21327106 DOI: 10.4161/nucl.1.1.10244] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2009] [Revised: 09/29/2009] [Accepted: 10/07/2009] [Indexed: 01/10/2023] Open
Abstract
The nucleoporin Nup153 is known to play pivotal roles in nuclear import and export in interphase cells and as the cell transitions into mitosis, Nup153 is involved in nuclear envelope breakdown. In this study, we demonstrate that the interaction of Nup153 with the spindle assembly checkpoint protein Mad1 is important in the regulation of the spindle checkpoint. Overexpression of human Nup153 in HeLa cells leads to the appearance of multinucleated cells and induces the formation of multipolar spindles. Importantly, it causes inactivation of the spindle checkpoint due to hypophosphorylation of Mad1. Depletion of Nup153 using RNA interference results in the decline of Mad1 at nuclear pores during interphase and more significantly causes a delayed dissociation of Mad1 from kinetochores in metaphase and an increase in the number of unresolved midbodies. In the absence of Nup153 the spindle checkpoint remains active. In vitro studies indicate direct binding of Mad1 to the N-terminal domain of Nup153. Importantly, Nup153 binding to Mad1 affects Mad1's phosphorylation status, but not its ability to interact with Mad2. Our data suggest that Nup153 levels regulate the localization of Mad1 during the metaphase/anaphase transition thereby affecting its phoshorylation status and in turn spindle checkpoint activity and mitotic exit.
Collapse
Affiliation(s)
- Yvonne C Lussi
- M.E. Müller Institute for Structural Biology, Biozentrum, University of Basel, Basel, Switzerland
| | | | | | | |
Collapse
|
44
|
Capturing directed molecular motion in the nuclear pore complex of live cells. Proc Natl Acad Sci U S A 2012; 109:9863-8. [PMID: 22665783 DOI: 10.1073/pnas.1200486109] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Nuclear pore complexes (NPCs) are gateways for nucleocytoplasmic exchange. Intrinsically disordered nucleoporins (Nups) form a selective filter inside the NPC, taking a central role in the vital nucleocytoplasmic transport mechanism. How such intricate meshwork relates to function and gives rise to a transport mechanism is still unclear. Here we set out to tackle this issue in intact cells by an established combination of fluorescence correlation spectroscopy and real-time tracking of the center of mass of single NPCs. We find the dynamics of nucleoporin Nup153 to be regulated so as to produce rapid, discrete exchange between two separate positions within the NPC. A similar behavior is also observed for both karyopherinβ1 transport-receptor and cargoes destined to nuclear import. Thus, we argue that directed Nup-mediated molecular motion may represent an intrinsic feature of the overall selective gating through intact NPCs.
Collapse
|
45
|
Chatel G, Fahrenkrog B. Dynamics and diverse functions of nuclear pore complex proteins. Nucleus 2012; 3:162-71. [PMID: 22555605 DOI: 10.4161/nucl.19674] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Nuclear pore complexes (NPCs) are best known for their central role in controlling the molecular trafficking between the cytoplasm and the nucleus. NPCs are assembled from about 30 different proteins and a growing body of evidence suggests that these nucleoporins are not only acting in the context of NPCs, but also in the nucleoplasm and cytoplasm. In this context it is well accepted that a set of nucleoporins are important regulators of a variety of mitotic processes, including kinetochore assembly, spindle checkpoint control and cytokinesis, whereas others associate with chromatin and administer gene expression. However, the functional importance of nucleoporins go far beyond these roles and this review will provide an overview of the latest insights into the versatility of metazoan nucleoporins with an emphasis on their roles in cell migration, cellular signaling and tissue-specific activities.
Collapse
Affiliation(s)
- Guillaume Chatel
- Institute of Molecular Biology and Medicine, Université Libre de Bruxelles, Charleroi, Belgium
| | | |
Collapse
|
46
|
Lui C, Mills K, Brocardo MG, Sharma M, Henderson BR. APC as a mobile scaffold: regulation and function at the nucleus, centrosomes, and mitochondria. IUBMB Life 2011; 64:209-14. [PMID: 22162224 DOI: 10.1002/iub.599] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Accepted: 11/02/2011] [Indexed: 12/13/2022]
Abstract
Genetic mutations of adenomatous polyposis coli (APC) predispose to high risk of human colon cancer. APC is a large tumor suppressor protein and truncating mutations disrupt its normal roles in regulating cell migration, DNA replication/repair, mitosis, apoptosis, and turnover of oncogenic β-catenin. APC is targeted to multiple subcellular sites, and here we discuss recent evidence implicating novel protein interactions and functions of APC in the nucleus and at centrosomes and mitochondria. The ability of APC to shuttle between these and other cell locations is hypothesized to be integral to its cellular function.
Collapse
Affiliation(s)
- Christina Lui
- Westmead Institute for Cancer Research, University of Sydney, Westmead Millennium Institute at Westmead Hospital, New South Wales, Australia
| | | | | | | | | |
Collapse
|
47
|
Monette A, Panté N, Mouland AJ. Examining the requirements for nucleoporins by HIV-1. Future Microbiol 2011; 6:1247-50. [DOI: 10.2217/fmb.11.111] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Evaluation of: Matreyek KA, Engelman A. The requirement for nucleoporin Nup153 during human immunodeficiency virus type 1 infection is determined by the viral capsid. J. Virol. 85(15), 7818–7827 (2011). A hallmark of HIV type 1 and other lentiviruses is their ability to infect and replicate in nondividing cells by commandeering host nuclear transport factors. During the early stages of infection, this is expected to permit the safe passage of viral preintegration complexes (PICs) through nuclear pores. Numerous nuclear transport factors have been identified as essential for HIV-1 infection by genome-wide small interfering RNA screens, and many of these are currently under investigation. Here, using knockdown studies, Matreyek and Engelman further characterize the importance of transportin-3 and nuclear pore complex component nucleoporin 153 for the early stages of HIV-1 infection and show that these two proteins operate synergistically. Also, as was previously observed for transportin-3, they show that the requirement of nucleoporin 153 for PIC nuclear entry is determined by the HIV-1 Capsid protein. The refinement of the list of key nuclear pore complex and transport proteins required for PIC entry, along with a better understanding of the specific mechanisms employed, will undoubtedly lead to the development of future antiretroviral therapies that will have the potential to block HIV-1 viral DNA integration.
Collapse
Affiliation(s)
- Anne Monette
- HIV-1 RNA Trafficking Laboratory, Lady Davis Institute for Medical Research, Sir Mortimer B. Davis Jewish General Hospital, Montréal, Québec, H3T 1E2, Canada
- Department of Medicine, Division of Experimental Medicine, McGill University, Montréal, Québec, H3A 1A3, Canada
| | - Nelly Panté
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, V6T 1Z4, Canada
| | - Andrew J Mouland
- Department of Microbiology & Immunology, McGill University, Montréal, Québec, H3A 2B4, Canada
| |
Collapse
|
48
|
Simon DN, Wilson KL. The nucleoskeleton as a genome-associated dynamic 'network of networks'. Nat Rev Mol Cell Biol 2011; 12:695-708. [PMID: 21971041 DOI: 10.1038/nrm3207] [Citation(s) in RCA: 222] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
In the cytosol, actin polymers, intermediate filaments and microtubules can anchor to cell surface adhesions and interlink to form intricate networks. This cytoskeleton is anchored to the nucleus through LINC (links the nucleoskeleton and cytoskeleton) complexes that span the nuclear envelope and in turn anchor to networks of filaments in the nucleus. The metazoan nucleoskeleton includes nuclear pore-linked filaments, A-type and B-type lamin intermediate filaments, nuclear mitotic apparatus (NuMA) networks, spectrins, titin, 'unconventional' polymers of actin and at least ten different myosin and kinesin motors. These elements constitute a poorly understood 'network of networks' that dynamically reorganizes during mitosis and is responsible for genome organization and integrity.
Collapse
Affiliation(s)
- Dan N Simon
- Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
| | | |
Collapse
|
49
|
Ando Y, Tomaru Y, Morinaga A, Burroughs AM, Kawaji H, Kubosaki A, Kimura R, Tagata M, Ino Y, Hirano H, Chiba J, Suzuki H, Carninci P, Hayashizaki Y. Nuclear pore complex protein mediated nuclear localization of dicer protein in human cells. PLoS One 2011; 6:e23385. [PMID: 21858095 PMCID: PMC3156128 DOI: 10.1371/journal.pone.0023385] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Accepted: 07/15/2011] [Indexed: 12/22/2022] Open
Abstract
Human DICER1 protein cleaves double-stranded RNA into small sizes, a crucial step in production of single-stranded RNAs which are mediating factors of cytoplasmic RNA interference. Here, we clearly demonstrate that human DICER1 protein localizes not only to the cytoplasm but also to the nucleoplasm. We also find that human DICER1 protein associates with the NUP153 protein, one component of the nuclear pore complex. This association is detected predominantly in the cytoplasm but is also clearly distinguishable at the nuclear periphery. Additional characterization of the NUP153-DICER1 association suggests NUP153 plays a crucial role in the nuclear localization of the DICER1 protein.
Collapse
Affiliation(s)
| | | | | | | | - Hideya Kawaji
- RIKEN Omics Science Center, Yokohama, Kanagawa, Japan
| | | | - Ryuichiro Kimura
- Department of Biological Science and Technology, Tokyo University of Science, Noda, Chiba, Japan
| | - Maiko Tagata
- Department of Biological Science and Technology, Tokyo University of Science, Noda, Chiba, Japan
| | - Yoko Ino
- Supramolecular Biology, International Graduate School of Arts and Sciences, Yokohama City University, Yokohama, Kanagawa, Japan
| | - Hisashi Hirano
- Supramolecular Biology, International Graduate School of Arts and Sciences, Yokohama City University, Yokohama, Kanagawa, Japan
| | - Joe Chiba
- Department of Biological Science and Technology, Tokyo University of Science, Noda, Chiba, Japan
| | | | | | | |
Collapse
|
50
|
The requirement for nucleoporin NUP153 during human immunodeficiency virus type 1 infection is determined by the viral capsid. J Virol 2011; 85:7818-27. [PMID: 21593146 DOI: 10.1128/jvi.00325-11] [Citation(s) in RCA: 167] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Lentiviruses likely infect nondividing cells by commandeering host nuclear transport factors to facilitate the passage of their preintegration complexes (PICs) through nuclear pore complexes (NPCs) within nuclear envelopes. Genome-wide small interfering RNA screens previously identified karyopherin β transportin-3 (TNPO3) and NPC component nucleoporin 153 (NUP153) as being important for infection by human immunodeficiency virus type 1 (HIV-1). The knockdown of either protein significantly inhibited HIV-1 infectivity, while infection by the gammaretrovirus Moloney murine leukemia virus (MLV) was unaffected. Here, we establish that primate lentiviruses are particularly sensitive to NUP153 knockdown and investigate HIV-1-encoded elements that contribute to this dependency. Mutants lacking functional Vpr or the central DNA flap remained sensitive to NUP153 depletion, while MLV/HIV-1 chimera viruses carrying MLV matrix, capsid, or integrase became less sensitive when the latter two elements were substituted. Two capsid missense mutant viruses, N74D and P90A, were largely insensitive to NUP153 depletion, as was wild-type HIV-1 when cyclophilin A was depleted simultaneously or when infection was conducted in the presence of cyclosporine A. The codepletion of NUP153 and TNPO3 yielded synergistic effects that outweighed those calculated based on individual knockdowns, indicating potential interdependent roles for these factors during HIV-1 infection. Quantitative PCR revealed normal levels of late reverse transcripts, a moderate reduction of 2-long terminal repeat (2-LTR) circles, and a relatively large reduction in integrated proviruses upon NUP153 knockdown. These results suggest that capsid, likely by the qualities of its uncoating, determines whether HIV-1 requires cellular NUP153 for PIC nuclear import.
Collapse
|