1
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Cantwell H, Nguyen H, Kettenbach A, Heald R. Spindle morphology changes between meiosis and mitosis driven by CK2 regulation of the Ran pathway. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.25.605073. [PMID: 39211121 PMCID: PMC11361180 DOI: 10.1101/2024.07.25.605073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
The transition from meiotic divisions in the oocyte to embryonic mitoses is a critical step in animal development. Despite negligible changes to cell size and shape, following fertilization the small, barrel-shaped meiotic spindle is replaced by a large zygotic spindle that nucleates abundant astral microtubules at spindle poles. To probe underlying mechanisms, we applied a drug screening approach using Ciona eggs and found that inhibition of Casein Kinase 2 (CK2) caused a shift from meiotic to mitotic-like spindle morphology with nucleation of robust astral microtubules, an effect reproduced in cytoplasmic extracts prepared from Xenopus eggs. In both species, CK2 activity decreased at fertilization. Phosphoproteomic differences between Xenopus meiotic and mitotic extracts that also accompanied CK2 inhibition pointed to RanGTP-regulated factors as potential targets. Interfering with RanGTP-driven microtubule formation suppressed astral microtubule growth caused by CK2 inhibition. These data support a model in which CK2 activity attenuation at fertilization leads to activation of RanGTP-regulated microtubule effectors that induce mitotic spindle morphology.
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2
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Loss of RanGAP1 drives chromosome instability and rapid tumorigenesis of osteosarcoma. Dev Cell 2023; 58:192-210.e11. [PMID: 36696903 DOI: 10.1016/j.devcel.2022.12.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 09/27/2022] [Accepted: 12/29/2022] [Indexed: 01/26/2023]
Abstract
Chromothripsis is a catastrophic event of chromosomal instability that involves intensive fragmentation and rearrangements within localized chromosomal regions. However, its cause remains unclear. Here, we show that reduction and inactivation of Ran GTPase-activating protein 1 (RanGAP1) commonly occur in human osteosarcoma, which is associated with a high rate of chromothripsis. In rapidly expanding mouse osteoprogenitors, RanGAP1 deficiency causes chromothripsis in chr1q, instant inactivation of Rb1 and degradation of p53, consequent failure in DNA damage repair, and ultrafast osteosarcoma tumorigenesis. During mitosis, RanGAP1 anchors to the kinetochore, where it recruits PP1-γ to counteract the activity of the spindle-assembly checkpoint (SAC) and prevents TOP2A degradation, thus safeguarding chromatid decatenation. Loss of RanGAP1 causes SAC hyperactivation and chromatid decatenation failure. These findings demonstrate that RanGAP1 maintains mitotic chromosome integrity and that RanGAP1 loss drives tumorigenesis through its direct effects on SAC and decatenation and secondary effects on DNA damage surveillance.
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3
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Audia S, Brescia C, Dattilo V, D’Antona L, Calvano P, Iuliano R, Trapasso F, Perrotti N, Amato R. RANBP1 (RAN Binding Protein 1): The Missing Genetic Piece in Cancer Pathophysiology and Other Complex Diseases. Cancers (Basel) 2023; 15:cancers15020486. [PMID: 36672435 PMCID: PMC9857238 DOI: 10.3390/cancers15020486] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 12/29/2022] [Accepted: 01/11/2023] [Indexed: 01/15/2023] Open
Abstract
RANBP1 encoded by RANBP1 or HTF9A (Hpall Tiny Fragments Locus 9A), plays regulatory functions of the RAN-network, belonging to the RAS superfamily of small GTPases. Through this function, RANBP1 regulates the RANGAP1 activity and, thus, the fluctuations between GTP-RAN and GDP-RAN. In the light of this, RANBP1 take actions in maintaining the nucleus-cytoplasmic gradient, thus making nuclear import-export functional. RANBP1 has been implicated in the inter-nuclear transport of proteins, nucleic acids and microRNAs, fully contributing to cellular epigenomic signature. Recently, a RANBP1 diriment role in spindle checkpoint formation and nucleation has emerged, thus constituting an essential element in the control of mitotic stability. Over time, RANBP1 has been demonstrated to be variously involved in human cancers both for the role in controlling nuclear transport and RAN activity and for its ability to determine the efficiency of the mitotic process. RANBP1 also appears to be implicated in chemo-hormone and radio-resistance. A key role of this small-GTPases related protein has also been demonstrated in alterations of axonal flow and neuronal plasticity, as well as in viral and bacterial metabolism and in embryological maturation. In conclusion, RANBP1 appears not only to be an interesting factor in several pathological conditions but also a putative target of clinical interest.
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Affiliation(s)
- Salvatore Audia
- Dipartimento di Scienze della Salute, Campus Salvatore Venuta, Università degli Studi “Magna Graecia” di Catanzaro, Viale Europa, 88100 Catanzaro, Italy
| | - Carolina Brescia
- Dipartimento di Scienze della Salute, Campus Salvatore Venuta, Università degli Studi “Magna Graecia” di Catanzaro, Viale Europa, 88100 Catanzaro, Italy
| | - Vincenzo Dattilo
- Dipartimento di Medicina Sperimentale e Clinica, Campus Salvatore Venuta, Università degli Studi “Magna Graecia” di Catanzaro, Viale Europa, 88100 Catanzaro, Italy
| | - Lucia D’Antona
- Dipartimento di Scienze della Salute, Campus Salvatore Venuta, Università degli Studi “Magna Graecia” di Catanzaro, Viale Europa, 88100 Catanzaro, Italy
| | - Pierluigi Calvano
- Dipartimento di Scienze della Salute, Campus Salvatore Venuta, Università degli Studi “Magna Graecia” di Catanzaro, Viale Europa, 88100 Catanzaro, Italy
| | - Rodolfo Iuliano
- Dipartimento di Scienze della Salute, Campus Salvatore Venuta, Università degli Studi “Magna Graecia” di Catanzaro, Viale Europa, 88100 Catanzaro, Italy
| | - Francesco Trapasso
- Dipartimento di Medicina Sperimentale e Clinica, Campus Salvatore Venuta, Università degli Studi “Magna Graecia” di Catanzaro, Viale Europa, 88100 Catanzaro, Italy
| | - Nicola Perrotti
- Dipartimento di Scienze della Salute, Campus Salvatore Venuta, Università degli Studi “Magna Graecia” di Catanzaro, Viale Europa, 88100 Catanzaro, Italy
| | - Rosario Amato
- Dipartimento di Scienze della Salute, Campus Salvatore Venuta, Università degli Studi “Magna Graecia” di Catanzaro, Viale Europa, 88100 Catanzaro, Italy
- Correspondence: ; Tel.: +39-0961-3694084
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He Y, Yang Z, Zhao CS, Xiao Z, Gong Y, Li YY, Chen Y, Du Y, Feng D, Altman A, Li Y. T-cell receptor (TCR) signaling promotes the assembly of RanBP2/RanGAP1-SUMO1/Ubc9 nuclear pore subcomplex via PKC-θ-mediated phosphorylation of RanGAP1. eLife 2021; 10:67123. [PMID: 34110283 PMCID: PMC8225385 DOI: 10.7554/elife.67123] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 06/03/2021] [Indexed: 01/15/2023] Open
Abstract
The nuclear pore complex (NPC) is the sole and selective gateway for nuclear transport, and its dysfunction has been associated with many diseases. The metazoan NPC subcomplex RanBP2, which consists of RanBP2 (Nup358), RanGAP1-SUMO1, and Ubc9, regulates the assembly and function of the NPC. The roles of immune signaling in regulation of NPC remain poorly understood. Here, we show that in human and murine T cells, following T-cell receptor (TCR) stimulation, protein kinase C-θ (PKC-θ) directly phosphorylates RanGAP1 to facilitate RanBP2 subcomplex assembly and nuclear import and, thus, the nuclear translocation of AP-1 transcription factor. Mechanistically, TCR stimulation induces the translocation of activated PKC-θ to the NPC, where it interacts with and phosphorylates RanGAP1 on Ser504 and Ser506. RanGAP1 phosphorylation increases its binding affinity for Ubc9, thereby promoting sumoylation of RanGAP1 and, finally, assembly of the RanBP2 subcomplex. Our findings reveal an unexpected role of PKC-θ as a direct regulator of nuclear import and uncover a phosphorylation-dependent sumoylation of RanGAP1, delineating a novel link between TCR signaling and assembly of the RanBP2 NPC subcomplex.
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Affiliation(s)
- Yujiao He
- MOE Key Laboratory of Gene Function and Regulation, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Zhiguo Yang
- MOE Key Laboratory of Gene Function and Regulation, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Chen-Si Zhao
- MOE Key Laboratory of Gene Function and Regulation, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Zhihui Xiao
- MOE Key Laboratory of Gene Function and Regulation, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Yu Gong
- MOE Key Laboratory of Gene Function and Regulation, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Yun-Yi Li
- MOE Key Laboratory of Gene Function and Regulation, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Yiqi Chen
- MOE Key Laboratory of Gene Function and Regulation, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Yunting Du
- MOE Key Laboratory of Gene Function and Regulation, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Dianying Feng
- MOE Key Laboratory of Gene Function and Regulation, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Amnon Altman
- Center for Cancer Immunotherapy, La Jolla Institute for Immunology, La Jolla, United States
| | - Yingqiu Li
- MOE Key Laboratory of Gene Function and Regulation, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
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5
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An ARF6-Exportin-5 axis delivers pre-miRNA cargo to tumour microvesicles. Nat Cell Biol 2019; 21:856-866. [PMID: 31235936 PMCID: PMC6697424 DOI: 10.1038/s41556-019-0345-y] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 05/16/2019] [Indexed: 02/07/2023]
Abstract
Tumor-derived microvesicles (TMVs) comprise a class of extracellular vesicles released from tumor cells that are now understood to facilitate communication between the tumor and the surrounding microenvironment. Despite their significance, the regulatory mechanisms governing the trafficking of bioactive cargos to TMVs at the cell surface remain poorly defined. Here we describe a molecular pathway for the delivery of microRNA (miRNA) cargo to nascent TMVs involving the dissociation of a pre-miRNA/Exportin-5 complex from Ran-GTP following nuclear export, and its subsequent transfer to a cytoplasmic shuttle comprised of ARF6-GTP and GRP1. As such, ARF6 activation increases pre-miRNA cargo contained within TMVs via a process that requires casein kinase 2-mediated phosphorylation of Ran-GAP1. Further, TMVs were found to contain pre-miRNA processing machinery including Dicer and Argonaute 2, which allow for cell-free pre-miRNA processing within shed vesicles. These findings offer cellular targets to block the loading and processing of pre-miRNAs within TMVs.
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de Gooijer MC, Guillén Navarro M, Bernards R, Wurdinger T, van Tellingen O. An Experimenter's Guide to Glioblastoma Invasion Pathways. Trends Mol Med 2018; 24:763-780. [PMID: 30072121 DOI: 10.1016/j.molmed.2018.07.003] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Revised: 07/03/2018] [Accepted: 07/06/2018] [Indexed: 12/25/2022]
Abstract
Glioblastoma is a highly aggressive brain tumor that is characterized by its unparalleled invasiveness. Invasive glioblastoma cells not only escape surgery and focal therapies but also are more resistant to current radio- and chemo-therapeutic approaches. Thus, any curative therapy for this deadly disease likely should include treatment strategies that interfere with glioblastoma invasiveness. Understanding glioblastoma invasion mechanisms is therefore critical. We discuss the strengths and weaknesses of various glioblastoma invasion models and conclude that robust experimental evidence has been obtained for a pro-invasive role of Ephrin receptors, Rho GTPases, and casein kinase 2 (CK2). Extensive interplay occurs between these proteins, suggesting the existence of a glioblastoma invasion signaling network that comprises several targets for therapy.
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Affiliation(s)
- Mark C de Gooijer
- Division of Pharmacology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands; These authors contributed equally to this work
| | - Miriam Guillén Navarro
- Division of Pharmacology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands; These authors contributed equally to this work
| | - Rene Bernards
- Division of Molecular Carcinogenesis, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
| | - Thomas Wurdinger
- Department of Neurosurgery, VU University Medical Center, Cancer Center Amsterdam, de Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Olaf van Tellingen
- Division of Pharmacology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands.
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7
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Franchin C, Borgo C, Cesaro L, Zaramella S, Vilardell J, Salvi M, Arrigoni G, Pinna LA. Re-evaluation of protein kinase CK2 pleiotropy: new insights provided by a phosphoproteomics analysis of CK2 knockout cells. Cell Mol Life Sci 2018; 75:2011-2026. [PMID: 29119230 PMCID: PMC11105740 DOI: 10.1007/s00018-017-2705-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 09/28/2017] [Accepted: 10/30/2017] [Indexed: 10/18/2022]
Abstract
CK2 denotes a ubiquitous and pleiotropic protein kinase whose holoenzyme is composed of two catalytic (α and/or α') and two regulatory β subunits. The CK2 consensus sequence, S/T-x-x-D/E/pS/pT is present in numerous phosphosites, but it is not clear how many of these are really generated by CK2. To gain information about this issue, advantage has been taken of C2C12 cells entirely deprived of both CK2 catalytic subunits by the CRISPR/Cas9 methodology. A comparative SILAC phosphoproteomics analysis reveals that, although about 30% of the quantified phosphosites do conform to the CK2 consensus, only one-third of these are substantially reduced in the CK2α/α'(-/-) cells, consistent with their generation by CK2. A parallel study with C2C12 cells deprived of the regulatory β subunit discloses a role of this subunit in determining CK2 targeting. We also find that phosphosites notoriously generated by CK2 are not fully abrogated in CK2α/α'(-/-) cells, while some phosphosites unrelated to CK2 are significantly altered. Collectively taken our data allow to conclude that the phosphoproteome generated by CK2 is not as ample and rigidly pre-determined as it was believed before. They also show that the lack of CK2 promotes phosphoproteomics perturbations attributable to kinases other than CK2.
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Affiliation(s)
- Cinzia Franchin
- Department of Biomedical Sciences, University of Padova, Via U. Bassi 58/B, Padua, Italy
- Proteomics Center, University of Padova and Azienda Ospedaliera di Padova, Via G. Orus 2/B, Padua, Italy
| | - Christian Borgo
- Department of Biomedical Sciences, University of Padova, Via U. Bassi 58/B, Padua, Italy
| | - Luca Cesaro
- Proteomics Center, University of Padova and Azienda Ospedaliera di Padova, Via G. Orus 2/B, Padua, Italy
| | - Silvia Zaramella
- Department of Biomedical Sciences, University of Padova, Via U. Bassi 58/B, Padua, Italy
- Proteomics Center, University of Padova and Azienda Ospedaliera di Padova, Via G. Orus 2/B, Padua, Italy
| | - Jordi Vilardell
- Department of Biomedical Sciences, University of Padova, Via U. Bassi 58/B, Padua, Italy
| | - Mauro Salvi
- Department of Biomedical Sciences, University of Padova, Via U. Bassi 58/B, Padua, Italy.
| | - Giorgio Arrigoni
- Department of Biomedical Sciences, University of Padova, Via U. Bassi 58/B, Padua, Italy.
- Proteomics Center, University of Padova and Azienda Ospedaliera di Padova, Via G. Orus 2/B, Padua, Italy.
| | - Lorenzo A Pinna
- Department of Biomedical Sciences, University of Padova, Via U. Bassi 58/B, Padua, Italy.
- CNR Institute of Neurosciences, Via U. Bassi 58/B, Padua, Italy.
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8
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Evaluation of the activity and substrate specificity of the human SENP family of SUMO proteases. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1863:139-47. [PMID: 26522917 DOI: 10.1016/j.bbamcr.2015.10.020] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 10/05/2015] [Accepted: 10/28/2015] [Indexed: 11/24/2022]
Abstract
Protein modification with the small ubiquitin-like modifier (SUMO) is a reversible process regulating many central biological pathways. The reversibility of SUMOylation is ensured by SUMO proteases many of which belong to the sentrin/SUMO-specific protease (SENP) family. In recent years, many advances have been made in allocating SENPs to specific biological pathways. However, due to difficulties in obtaining recombinant full-length active SENPs for thorough enzymatic characterization, our knowledge on these proteases is still limited. In this work, we used in vitro synthesized full-length human SENPs to perform a side-by-side comparison of their activities and substrate specificities. ProSUMO1/2/3, RanGAP1-SUMO1/2/3 and polySUMO2/3 chains were used as substrates in these analyses. We found that SENP1 is by far the most versatile and active SENP whereas SENP3 stands out as the least active of these enzymes. Finally, a comparison between the activities of full-length SENPs and their catalytic domains suggests that in some cases their non-catalytic regions influence their activity.
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Mai HJ, Lindermayr C, von Toerne C, Fink-Straube C, Durner J, Bauer P. Iron and FER-LIKE IRON DEFICIENCY-INDUCED TRANSCRIPTION FACTOR-dependent regulation of proteins and genes in Arabidopsis thaliana
roots. Proteomics 2015; 15:3030-47. [DOI: 10.1002/pmic.201400351] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Revised: 03/10/2015] [Accepted: 04/30/2015] [Indexed: 11/06/2022]
Affiliation(s)
- Hans-Jörg Mai
- Institute of Botany; Heinrich Heine University Düsseldorf; Düsseldorf Germany
| | - Christian Lindermayr
- Helmholtz Zentrum München (GmbH); German Research Center for Environmental Health; Institute of Biochemical Plant Pathology (BIOP); Neuherberg Germany
| | - Christine von Toerne
- Research Unit Protein Science; Helmholtz Zentrum München (GmbH); German Research Center for Environmental Health; Neuherberg Germany
| | | | - Jörg Durner
- Helmholtz Zentrum München (GmbH); German Research Center for Environmental Health; Institute of Biochemical Plant Pathology (BIOP); Neuherberg Germany
| | - Petra Bauer
- Institute of Botany; Heinrich Heine University Düsseldorf; Düsseldorf Germany
- CEPLAS Cluster of Excellence on Plant Sciences; Heinrich Heine Universität Düsseldorf; Düsseldorf Germany
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10
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Khan U, Mehere P, Deivasigamani S, Ratnaparkhi GS. The Hydra small ubiquitin-like modifier. Genesis 2013; 51:619-29. [PMID: 23780789 DOI: 10.1002/dvg.22408] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2012] [Revised: 05/05/2013] [Accepted: 06/06/2013] [Indexed: 12/25/2022]
Abstract
SUMO is a protein posttranslational modifier. SUMO cycle components are believed to be conserved in all eukaryotes. Proteomic analyses have lead to the identification a wealth of SUMO targets that are involved in almost every cellular function in eukaryotes. In this article, we describe the characterization of SUMO Cycle components in Hydra, a Cnidarian with an ability to regenerate body parts. In cells, the translated SUMO polypeptide cannot conjugate to a substrate protein unless the C-terminal tail is cleaved, exposing the di-Glycine motif. This critical task is done by SUMO proteases that in addition to SUMO maturation are also involved in deconjugating SUMO from its substrate. We describe the identification, bioinformatics analysis, cloning, and biochemical characterization of Hydra SUMO cycle components, with a focus on SUMO and SUMO proteases. We demonstrate that the ability of SUMO proteases to process immature SUMO is conserved from Hydra to flies. A transgenic Hydra, expressing a SUMO-GFP fusion protein under a constitutive actin promoter, is generated in an attempt to monitor the SUMO Cycle in vivo as also to purify and identify SUMO targets in Hydra.
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Affiliation(s)
- Umair Khan
- Biology, Indian Institute of Science Education and Research, Pune, India
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11
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Asakawa H, Hiraoka Y, Haraguchi T. Physical breakdown of the nuclear envelope is not necessary for breaking its barrier function. Nucleus 2011; 2:523-6. [PMID: 22064471 PMCID: PMC3324341 DOI: 10.4161/nucl.2.6.16117] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
During mitosis in higher eukaryotic cells, nuclear envelope breakdown (NEBD) occurs and leads to the disassembly of the nuclear membrane and nuclear pore complexes (NPC). This brings about a mixing of nuclear and cytoplasmic macromolecules (open mitosis). On the other hand, in many fungi, mitosis occurs without NEBD (closed mitosis). In a recent study, we reported a novel phenomenon in a closed mitosis organism, Schizosaccharomyces pombe: mixing of nuclear and cytoplasmic proteins occurred in meiosis without breakdown of the nuclear membrane or disassembly of nuclear pore complexes. We designated this event virtual nuclear envelope breakdown (V-NEBD). The key event in V-NEBD is nuclear translocation of Rna1, a RanGAP1 homolog in S. pombe. This leads to collapse of the Ran-GTP gradient across the nuclear envelope (NE) and occurs coincidently with V-NEBD. Thus, the barrier function of the NE can be abated without its physical breakdown through modulation of the Ran-GTP gradient.
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Affiliation(s)
- Haruhiko Asakawa
- Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka, Japan
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12
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Nuclear retention of importin α coordinates cell fate through changes in gene expression. EMBO J 2011; 31:83-94. [PMID: 21964068 DOI: 10.1038/emboj.2011.360] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2010] [Accepted: 09/06/2011] [Indexed: 01/01/2023] Open
Abstract
Various cellular stresses including oxidative stress induce a collapse of the Ran gradient, which causes accumulation of importin α in the nucleus and a subsequent block of nuclear protein import. However, it is unknown whether accumulated importin α performs roles in the nucleus after its migration in response to stress. In this study, we found that nuclear-retained importin α2 binds with DNase I-sensitive nuclear component(s) and exhibits selective upregulation of mRNA encoding Serine/threonine kinase 35 (STK35) by microarray analysis. Chromatin immunoprecipitation and promoter analysis demonstrated that importin α2 can access to the promoter region of STK35 and accelerate its transcription in response to hydrogen peroxide exposure. Furthermore, constitutive overexpression of STK35 proteins enhances caspase-independent cell death under oxidative stress conditions. These results collectively reveal that nuclear-localized importin α2 influences gene expression and contributes directly to cell fate outcomes including non-apoptotic cell death.
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13
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Tsolmon S, Nakazaki E, Han J, Isoda H. Apigetrin induces erythroid differentiation of human leukemia cells K562: Proteomics approach. Mol Nutr Food Res 2011; 55 Suppl 1:S93-S102. [DOI: 10.1002/mnfr.201000650] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Revised: 01/18/2011] [Accepted: 02/21/2011] [Indexed: 01/11/2023]
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14
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Oka M, Asally M, Yasuda Y, Ogawa Y, Tachibana T, Yoneda Y. The mobile FG nucleoporin Nup98 is a cofactor for Crm1-dependent protein export. Mol Biol Cell 2010; 21:1885-96. [PMID: 20375145 PMCID: PMC2877646 DOI: 10.1091/mbc.e09-12-1041] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2009] [Revised: 03/26/2010] [Accepted: 03/29/2010] [Indexed: 12/18/2022] Open
Abstract
Nup98 is a mobile nucleoporin that forms distinct dots in the nucleus, and, although a role for Nup98 in nuclear transport has been suggested, its precise function remains unclear. Here, we show that Nup98 plays an important role in Crm1-mediated nuclear protein export. Nuclear, but not cytoplasmic, dots of EGFP-tagged Nup98 disappeared rapidly after cell treatment with leptomycin B, a specific inhibitor of the nuclear export receptor, Crm1. Mutational analysis demonstrated that Nup98 physically and functionally interacts with Crm1 in a RanGTP-dependent manner through its N-terminal phenylalanine-glycine (FG) repeat region. Moreover, the activity of the Nup98-Crm1 complex was modulated by RanBP3, a known cofactor for Crm1-mediated nuclear export. Finally, cytoplasmic microinjection of anti-Nup98 inhibited the Crm1-dependent nuclear export of proteins, concomitant with the accumulation of anti-Nup98 in the nucleus. These results clearly demonstrate that Nup98 functions as a novel shuttling cofactor for Crm1-mediated nuclear export in conjunction with RanBP3.
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Affiliation(s)
- Masahiro Oka
- *Biomolecular Dynamics Group, Graduate School of Frontier Biosciences
- Department of Biochemistry, Graduate School of Medicine, Osaka University, and
- Japan Science and Technology Corporation (JST), Core Research for Evolution Science and Technology (CREST), Osaka University, Suita, Osaka 565-0871, Japan; and
| | - Munehiro Asally
- *Biomolecular Dynamics Group, Graduate School of Frontier Biosciences
| | - Yoshinari Yasuda
- *Biomolecular Dynamics Group, Graduate School of Frontier Biosciences
| | - Yutaka Ogawa
- *Biomolecular Dynamics Group, Graduate School of Frontier Biosciences
| | - Taro Tachibana
- Department of Bioengineering, Graduate School of Engineering, Osaka City University, Osaka 558-8585, Japan
| | - Yoshihiro Yoneda
- *Biomolecular Dynamics Group, Graduate School of Frontier Biosciences
- Department of Biochemistry, Graduate School of Medicine, Osaka University, and
- Japan Science and Technology Corporation (JST), Core Research for Evolution Science and Technology (CREST), Osaka University, Suita, Osaka 565-0871, Japan; and
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15
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Malik R, Lenobel R, Santamaria A, Ries A, Nigg EA, Körner R. Quantitative analysis of the human spindle phosphoproteome at distinct mitotic stages. J Proteome Res 2010; 8:4553-63. [PMID: 19691289 DOI: 10.1021/pr9003773] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
During mitosis, phosphorylation of spindle associated proteins is a key regulatory mechanism for spindle formation, mitotic progression, and cytokinesis. In the recent past, mass spectrometry has been applied successfully to identify spindle proteomes and phosphoproteomes, but did not address their dynamics. Here, we present a quantitative comparison of spindle phosphoproteomes prepared from different mitotic stages. In total, we report the identification and SILAC based relative quantitation of 1940 unique phosphorylation sites and find that late mitosis (anaphase, telophase) is correlated with a drastic alteration in protein phosphorylation. Further statistical cluster analyses demonstrate a strong dependency of phosphorylation dynamics on kinase consensus patterns, thus, linking subgroups of identified phosphorylation sites to known key mitotic kinases. Surprisingly, we observed that during late mitosis strong dephosphorylation occurred on a significantly larger fraction of phospho-threonine than phospho-serine residues, suggesting a substrate preference of phosphatases for phospho-threonine at this stage. Taken together, our results constitute a large quantitative data resource of phosphorylation abundances at distinct mitotic stages and they provide insight into the systems properties of phosphorylation dynamics during mitosis.
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Affiliation(s)
- Rainer Malik
- Max Planck Institute of Biochemistry, Department of Cell Biology, Am Klopferspitz 18, D-82152 Martinsried, Germany
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Jones AME, MacLean D, Studholme DJ, Serna-Sanz A, Andreasson E, Rathjen JP, Peck SC. Phosphoproteomic analysis of nuclei-enriched fractions from Arabidopsis thaliana. J Proteomics 2009; 72:439-51. [PMID: 19245862 DOI: 10.1016/j.jprot.2009.02.004] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2008] [Revised: 02/08/2009] [Accepted: 02/12/2009] [Indexed: 11/25/2022]
Abstract
Phosphorylation is a ubiquitous regulatory mechanism, that governs the activity, subcellular localisation and molecular interactions of proteins. To identify a broad range of nuclear phosphoproteins from Arabidopsis thaliana, we enriched for nuclei from suspension cell cultures and seedlings before extensive fractionation and identification of phosphopeptides by mass spectrometry. We identified 416 phosphopeptides from 345 proteins with high confidence. Our data show that sub-cellular fractionation is an effective strategy for identifying nuclear phosphoproteins, two thirds of our dataset are known or predicted to be nuclear localised and one half of the nuclear localised proteins have novel phosphorylation sites. We identified novel phosphorylation sites on transcription factors, chromatin remodelling proteins, RNA silencing components and the spliceosome. Intriguingly, we also identified phosphorylation sites on several proteins associated with Golgi vesicle trafficking such as the exocyst complex, and speculate that these may be involved in cell plate formation during cytokinesis.
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Affiliation(s)
- Alexandra M E Jones
- The Sainsbury Laboratory, Norwich Research Park, Colney Lane, Norwich, United Kingdom.
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