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Jing S, Gao J, Tiwari N, Du Y, Zhu L, Gim B, Qian Y, Yue X, Lee I. SUMOylated Golgin45 associates with PML-NB to transcriptionally regulate lipid metabolism genes during heat shock stress. Commun Biol 2024; 7:532. [PMID: 38710927 PMCID: PMC11074300 DOI: 10.1038/s42003-024-06232-3] [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: 09/23/2022] [Accepted: 04/23/2024] [Indexed: 05/08/2024] Open
Abstract
Golgin tethers are known to mediate vesicular transport in the secretory pathway, whereas it is relatively unknown whether they may mediate cellular stress response within the cell. Here, we describe a cellular stress response during heat shock stress via SUMOylation of a Golgin tether, Golgin45. We found that Golgin45 is a SUMOylated Golgin via SUMO1 under steady state condition. Upon heat shock stress, the Golgin enters the nucleus by interacting with Importin-β2 and gets further modified by SUMO3. Importantly, SUMOylated Golgin45 appears to interact with PML and SUMO-deficient Golgin45 mutant functions as a dominant negative for PML-NB formation during heat shock stress, suppressing transcription of lipid metabolism genes. These results indicate that Golgin45 may play a role in heat stress response by transcriptional regulation of lipid metabolism genes in SUMOylation-dependent fashion.
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Affiliation(s)
- Shuaiyang Jing
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Jingkai Gao
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Neeraj Tiwari
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, 06520, USA
| | - Yulei Du
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Lianhui Zhu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Bopil Gim
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, China
| | - Yi Qian
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China.
| | - Xihua Yue
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China.
| | - Intaek Lee
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China.
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2
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Cheng X, Yang W, Lin W, Mei F. Paradoxes of Cellular SUMOylation Regulation: A Role of Biomolecular Condensates? Pharmacol Rev 2023; 75:979-1006. [PMID: 37137717 PMCID: PMC10441629 DOI: 10.1124/pharmrev.122.000784] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 04/20/2023] [Accepted: 04/27/2023] [Indexed: 05/05/2023] Open
Abstract
Protein SUMOylation is a major post-translational modification essential for maintaining cellular homeostasis. SUMOylation has long been associated with stress responses as a diverse array of cellular stress signals are known to trigger rapid alternations in global protein SUMOylation. In addition, while there are large families of ubiquitination enzymes, all small ubiquitin-like modifiers (SUMOs) are conjugated by a set of enzymatic machinery comprising one heterodimeric SUMO-activating enzyme, a single SUMO-conjugating enzyme, and a small number of SUMO protein ligases and SUMO-specific proteases. How a few SUMOylation enzymes specifically modify thousands of functional targets in response to diverse cellular stresses remains an enigma. Here we review recent progress toward understanding the mechanisms of SUMO regulation, particularly the potential roles of liquid-liquid phase separation/biomolecular condensates in regulating cellular SUMOylation during cellular stresses. In addition, we discuss the role of protein SUMOylation in pathogenesis and the development of novel therapeutics targeting SUMOylation. SIGNIFICANCE STATEMENT: Protein SUMOylation is one of the most prevalent post-translational modifications and plays a vital role in maintaining cellular homeostasis in response to stresses. Protein SUMOylation has been implicated in human pathogenesis, such as cancer, cardiovascular diseases, neurodegeneration, and infection. After more than a quarter century of extensive research, intriguing enigmas remain regarding the mechanism of cellular SUMOylation regulation and the therapeutic potential of targeting SUMOylation.
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Affiliation(s)
- Xiaodong Cheng
- Department of Integrative Biology & Pharmacology and Texas Therapeutics Institute, Institute of Molecular Medicine, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, Texas
| | - Wenli Yang
- Department of Integrative Biology & Pharmacology and Texas Therapeutics Institute, Institute of Molecular Medicine, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, Texas
| | - Wei Lin
- Department of Integrative Biology & Pharmacology and Texas Therapeutics Institute, Institute of Molecular Medicine, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, Texas
| | - Fang Mei
- Department of Integrative Biology & Pharmacology and Texas Therapeutics Institute, Institute of Molecular Medicine, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, Texas
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3
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Strong A, Qu H, Cullina S, McManus M, Zackai EH, Glessner J, Kenny EE, Hakonarson H. TOPORS as a novel causal gene for Joubert syndrome. Am J Med Genet A 2023; 191:2156-2163. [PMID: 37227088 PMCID: PMC10449431 DOI: 10.1002/ajmg.a.63303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 04/25/2023] [Accepted: 05/10/2023] [Indexed: 05/26/2023]
Abstract
Joubert syndrome (JBTS) is a Mendelian disorder of the primary cilium defined by the clinical triad of hypotonia, developmental delay, and a distinct cerebellar malformation called the molar tooth sign. JBTS is inherited in an autosomal recessive, autosomal dominant, or X-linked recessive manner. Though over 40 genes have been identified as causal for JBTS, molecular diagnosis is not made in 30%-40% of individuals who meet clinical criteria. TOPORS encodes topoisomerase I-binding arginine/serine-rich protein, and homozygosity for a TOPORS missense variant (c.29C > A; p.(Pro10Gln)) was identified in individuals with the ciliopathy oral-facial-digital syndrome in two families of Dominican descent. Here, we report an additional proband of Dominican ancestry with JBTS found by exome sequencing to be homozygous for the identical p.(Pro10Gln) TOPORS missense variant. Query of the Mount Sinai BioMe biobank, which includes 1880 individuals of Dominican ancestry, supports a high carrier frequency of the TOPORS p.(Pro10Gln) variant in individuals of Dominican descent. Our data nominates TOPORS as a novel causal gene for JBTS and suggests that TOPORS variants should be considered in the differential of ciliopathy-spectrum disease in individuals of Dominican ancestry.
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Affiliation(s)
- Alanna Strong
- The Division of Human Genetics, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania
- The Center for Applied Genomics, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania
- Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Huiqi Qu
- The Center for Applied Genomics, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Sinéad Cullina
- Institute for Genomic Health, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Morgan McManus
- The Division of Human Genetics, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Elaine H. Zackai
- The Division of Human Genetics, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania
- Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Joseph Glessner
- The Center for Applied Genomics, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania
- Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Eimear E. Kenny
- Institute for Genomic Health, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Division of Genomic Medicine, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Hakon Hakonarson
- The Division of Human Genetics, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania
- The Center for Applied Genomics, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania
- Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
- Division of Pulmonary Medicine, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania
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4
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Mandel N, Agarwal N. Role of SUMOylation in Neurodegenerative Diseases. Cells 2022; 11:3395. [PMID: 36359791 PMCID: PMC9654019 DOI: 10.3390/cells11213395] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 10/23/2022] [Accepted: 10/24/2022] [Indexed: 09/26/2023] Open
Abstract
Neurodegenerative diseases (NDDs) are irreversible, progressive diseases with no effective treatment. The hallmark of NDDs is the aggregation of misfolded, modified proteins, which impair neuronal vulnerability and cause brain damage. The loss of synaptic connection and the progressive loss of neurons result in cognitive defects. Several dysregulated proteins and overlapping molecular mechanisms contribute to the pathophysiology of NDDs. Post-translational modifications (PTMs) are essential regulators of protein function, trafficking, and maintaining neuronal hemostasis. The conjugation of a small ubiquitin-like modifier (SUMO) is a reversible, dynamic PTM required for synaptic and cognitive function. The onset and progression of neurodegenerative diseases are associated with aberrant SUMOylation. In this review, we have summarized the role of SUMOylation in regulating critical proteins involved in the onset and progression of several NDDs.
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Affiliation(s)
| | - Nitin Agarwal
- Institute of Pharmacology, Medical Faculty Heidelberg, Heidelberg University, 69120 Heidelberg, Germany
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Hariharasudhan G, Jeong SY, Kim MJ, Jung SM, Seo G, Moon JR, Lee S, Chang IY, Kee Y, You H, Lee JH. OUP accepted manuscript. Nucleic Acids Res 2022; 50:1501-1516. [PMID: 35061896 PMCID: PMC8860612 DOI: 10.1093/nar/gkac009] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 12/23/2021] [Accepted: 01/13/2022] [Indexed: 11/24/2022] Open
Abstract
Homologous recombination (HR) is critical for error-free repair of DNA double-strand breaks. Chromatin loading of RAD51, a key protein that mediates the recombination, is a crucial step in the execution of the HR repair. Here, we present evidence that SUMOylation of RAD51 is crucial for the RAD51 recruitment to chromatin and HR repair. We found that topoisomerase 1-binding arginine/serine-rich protein (TOPORS) induces the SUMOylation of RAD51 at lysine residues 57 and 70 in response to DNA damaging agents. The SUMOylation was facilitated by an ATM-induced phosphorylation of TOPORS at threonine 515 upon DNA damage. Knockdown of TOPORS or expression of SUMOylation-deficient RAD51 mutants caused reduction in supporting normal RAD51 functions during the HR repair, suggesting the physiological importance of the modification. We found that the SUMOylation-deficient RAD51 reduces the association with its crucial binding partner BRCA2, explaining its deficiency in supporting the HR repair. These findings altogether demonstrate a crucial role for TOPORS-mediated RAD51 SUMOylation in promoting HR repair and genomic maintenance.
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Affiliation(s)
- Gurusamy Hariharasudhan
- Laboratory of Genomic Instability and Cancer Therapeutics, Chosun University School of Medicine, 309 Pilmun-daero, Dong-gu, Gwangju 61452, Republic of Korea
- Department of Cellular and Molecular Medicine, Chosun University School of Medicine, 309 Pilmun-daero, Dong-gu, Gwangju 61452, Republic of Korea
| | - Seo-Yeon Jeong
- Laboratory of Genomic Instability and Cancer Therapeutics, Chosun University School of Medicine, 309 Pilmun-daero, Dong-gu, Gwangju 61452, Republic of Korea
- Department of Pharmacology, Chosun University School of Medicine, 309 Pilmun-daero, Dong-gu, Gwangju 61452, Republic of Korea
| | - Min-Ji Kim
- Laboratory of Genomic Instability and Cancer Therapeutics, Chosun University School of Medicine, 309 Pilmun-daero, Dong-gu, Gwangju 61452, Republic of Korea
- Department of Cellular and Molecular Medicine, Chosun University School of Medicine, 309 Pilmun-daero, Dong-gu, Gwangju 61452, Republic of Korea
| | - Sung Mi Jung
- Laboratory of Genomic Instability and Cancer Therapeutics, Chosun University School of Medicine, 309 Pilmun-daero, Dong-gu, Gwangju 61452, Republic of Korea
- Department of Cellular and Molecular Medicine, Chosun University School of Medicine, 309 Pilmun-daero, Dong-gu, Gwangju 61452, Republic of Korea
| | - Gwanwoo Seo
- Laboratory of Genomic Instability and Cancer Therapeutics, Chosun University School of Medicine, 309 Pilmun-daero, Dong-gu, Gwangju 61452, Republic of Korea
- Department of Pharmacology, Chosun University School of Medicine, 309 Pilmun-daero, Dong-gu, Gwangju 61452, Republic of Korea
| | - Ju-Ran Moon
- Laboratory of Genomic Instability and Cancer Therapeutics, Chosun University School of Medicine, 309 Pilmun-daero, Dong-gu, Gwangju 61452, Republic of Korea
- Department of Cellular and Molecular Medicine, Chosun University School of Medicine, 309 Pilmun-daero, Dong-gu, Gwangju 61452, Republic of Korea
| | - Sumi Lee
- Laboratory of Genomic Instability and Cancer Therapeutics, Chosun University School of Medicine, 309 Pilmun-daero, Dong-gu, Gwangju 61452, Republic of Korea
- Department of Cellular and Molecular Medicine, Chosun University School of Medicine, 309 Pilmun-daero, Dong-gu, Gwangju 61452, Republic of Korea
| | - In-Youb Chang
- Department of Anatomy, Chosun University School of Medicine, 309 Pilmun-daero, Dong-gu, Gwangju 61452, Republic of Korea
| | - Younghoon Kee
- Correspondence may also be addressed to Younghoon Kee. Tel: +82 53 785 1610;
| | - Ho Jin You
- Correspondence may also be addressed to Ho Jin You. Tel: +82 62 230 6337;
| | - Jung-Hee Lee
- To whom correspondence should be addressed. Tel: +82 62 230 6399;
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6
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Sun Y, Miller Jenkins LM, Su YP, Nitiss KC, Nitiss JL, Pommier Y. A conserved SUMO pathway repairs topoisomerase DNA-protein cross-links by engaging ubiquitin-mediated proteasomal degradation. SCIENCE ADVANCES 2020; 6:6/46/eaba6290. [PMID: 33188014 PMCID: PMC7673754 DOI: 10.1126/sciadv.aba6290] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 09/24/2020] [Indexed: 05/04/2023]
Abstract
Topoisomerases form transient covalent DNA cleavage complexes to perform their reactions. Topoisomerase I cleavage complexes (TOP1ccs) are trapped by camptothecin and TOP2ccs by etoposide. Proteolysis of the trapped topoisomerase DNA-protein cross-links (TOP-DPCs) is a key step for some pathways to repair these lesions. We describe a pathway that features a prominent role of the small ubiquitin-like modifier (SUMO) modification for both TOP1- and TOP2-DPC repair. Both undergo rapid and sequential SUMO-2/3 and SUMO-1 modifications in human cells. The SUMO ligase PIAS4 is required for these modifications. RNF4, a SUMO-targeted ubiquitin ligase (STUbL), then ubiquitylates the TOP-DPCs for their subsequent degradation by the proteasome. This pathway is conserved in yeast with Siz1 and Slx5-Slx8, the orthologs of human PIAS4 and RNF4.
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Affiliation(s)
- Yilun Sun
- Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, NCI, NIH, Bethesda, MD 20892, USA.
- Department of Biopharmaceutical Sciences, College of Pharmacy, University of Illinois, Rockford, IL 61107, USA
| | - Lisa M Miller Jenkins
- Collaborative Protein Technology Resource, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Yijun P Su
- Advanced Imaging and Microscopy Resource, National Institute of Biomedical Imaging and Bioengineering, NIH, MD 20892, USA
| | - Karin C Nitiss
- Department of Biopharmaceutical Sciences, College of Pharmacy, University of Illinois, Rockford, IL 61107, USA
| | - John L Nitiss
- Department of Biopharmaceutical Sciences, College of Pharmacy, University of Illinois, Rockford, IL 61107, USA.
| | - Yves Pommier
- Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, NCI, NIH, Bethesda, MD 20892, USA.
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7
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Princz A, Tavernarakis N. The role of SUMOylation in ageing and senescent decline. Mech Ageing Dev 2017; 162:85-90. [PMID: 28088449 DOI: 10.1016/j.mad.2017.01.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 01/03/2017] [Accepted: 01/05/2017] [Indexed: 02/07/2023]
Abstract
Posttranslational protein modifications are playing crucial roles in essential cellular mechanisms. SUMOylation is a reversible posttranslational modification of specific target proteins by the attachment of a small ubiquitin-like protein. Although the mechanism of conjugation of SUMO to proteins is analogous to ubiquitination, it requires its own, specific set of enzymes. The consequences of SUMOylation are widely variable, depending on the physiological state of the cell and the attached SUMO isoform. Accumulating recent findings have revealed a prominent role of SUMOylation in molecular pathways that govern senescence and ageing. Here, we review the link between SUMO attachment events and cellular processes that influence senescence and ageing, including promyelocytic leukaemia (PML) nuclear body and telomere function, autophagy, reactive oxygen species (ROS) homeostasis and growth factor signalling.
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Affiliation(s)
- Andrea Princz
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Department of Basic Sciences, Faculty of Medicine, University of Crete, N. Plastira 100, Vassilika Vouton, Heraklion, 71110, Crete, Greece
| | - Nektarios Tavernarakis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Department of Basic Sciences, Faculty of Medicine, University of Crete, N. Plastira 100, Vassilika Vouton, Heraklion, 71110, Crete, Greece.
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8
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TOPORS, a Dual E3 Ubiquitin and Sumo1 Ligase, Interacts with 26 S Protease Regulatory Subunit 4, Encoded by the PSMC1 Gene. PLoS One 2016; 11:e0148678. [PMID: 26872363 PMCID: PMC4752349 DOI: 10.1371/journal.pone.0148678] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2015] [Accepted: 01/20/2016] [Indexed: 11/19/2022] Open
Abstract
The significance of the ubiquitin-proteasome system (UPS) for protein degradation has been highlighted in the context of neurodegenerative diseases, including retinal dystrophies. TOPORS, a dual E3 ubiquitin and SUMO1 ligase, forms a component of the UPS and selected substrates for its enzymatic activities, such as DJ-1/PARK7 and APOBEC2, are important for neuronal as well as retinal homeostasis, respectively. TOPORS is ubiquitously expressed, yet its mutations are only known to result in autosomal dominant retinitis pigmentosa. We performed a yeast two-hybrid (Y2H) screen of a human retinal cDNA library in order to identify interacting protein partners of TOPORS from the retina, and thus begin delineating the putative disease mechanism(s) associated with the retina-specific phenotype resulting from mutations in TOPORS. The screen led to isolation of the 26 S protease regulatory subunit 4 (P26s4/ PSMC1), an ATPase indispensable for correct functioning of UPS-mediated proteostasis. The interaction between endogenous TOPORS and P26s4 proteins was validated by co-immuno-precipitation from mammalian cell extracts and further characterised by immunofluorescent co-localisation studies in cell lines and retinal sections. Findings from hTERT-RPE1 and 661W cells demonstrated that TOPORS and P26s4 co-localise at the centrosome in cultured cells. Immunofluorescent staining of mouse retinae revealed a strong P26s4 reactivity at the interface between retinal pigmented epithelium (RPE) layer and the photoreceptors outer segments (OS). This finding leads us to speculate that P26s4, along with TOPORS, may have a role(s) in RPE phagocytosis, in addition to contributing to the overall photoreceptor and retinal homeostasis via the UPS.
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9
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Sahin U, de Thé H, Lallemand-Breitenbach V. PML nuclear bodies: assembly and oxidative stress-sensitive sumoylation. Nucleus 2015; 5:499-507. [PMID: 25482067 DOI: 10.4161/19491034.2014.970104] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
PML Nuclear Bodies (NBs) have fascinated cell biologists due to their exquisitely dynamic nature and their involvement in human diseases, notably acute promyelocytic leukemia. NBs, as well as their master organizer--the PML protein--exhibit multiple connections with stress responses. Initially viewed as a tumor suppressor, PML recently re-emerged as a multifaceted protein, capable of controlling numerous aspects of cellular homeostasis. NBs recruit many functionally diverse proteins and function as stress-regulated sumoylation factories. SUMO-initiated partner retention can subsequently facilitate a variety of other post-translational modifications, as well as partner degradation. With this newly elucidated central role of stress-enhanced sumoylation, it should now be possible to build a working model for the different NB-regulated cellular activities. Moreover, pharmacological manipulation of NB formation by interferons or oxidants holds the promise of clearing many undesirable proteins for clinical management of malignant, viral or neurodegenerative diseases.
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Affiliation(s)
- Umut Sahin
- a University Paris Diderot; Sorbonne Paris Cité ; Hôpital St. Louis ; Paris , France
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10
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McIntyre JC, Joiner AM, Zhang L, Iñiguez-Lluhí J, Martens JR. SUMOylation regulates ciliary localization of olfactory signaling proteins. J Cell Sci 2015; 128:1934-45. [PMID: 25908845 PMCID: PMC4457158 DOI: 10.1242/jcs.164673] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 03/24/2015] [Indexed: 11/20/2022] Open
Abstract
Cilia are evolutionarily conserved organelles found on many mammalian cell types, including neuronal populations. Although neuronal cilia, including those on olfactory sensory neurons (OSNs), are often delineated by localization of adenylyl cyclase 3 (AC3, also known as ADCY3), the mechanisms responsible for targeting integral membrane proteins are largely unknown. Post-translational modification by small ubiquitin-like modifier (SUMO) proteins plays an important role in protein localization processes such as nuclear-cytosolic transport. Here, we identified through bioinformatic analysis that adenylyl cyclases harbor conserved SUMOylation motifs, and show that AC3 is a substrate for SUMO modification. Functionally, overexpression of the SUMO protease SENP2 prevented ciliary localization of AC3, without affecting ciliation or cilia maintenance. Furthermore, AC3-SUMO mutants did not localize to cilia. To test whether SUMOylation is sufficient for cilia entry, we compared localization of ANO2, which possesses a SUMO motif, and ANO1, which lacks SUMOylation sites and does not localize to cilia. Introduction of SUMOylation sites into ANO1 was not sufficient for ciliary entry. These data suggest that SUMOylation is necessary but not sufficient for ciliary trafficking of select constituents, further establishing the link between ciliary and nuclear import.
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Affiliation(s)
- Jeremy C McIntyre
- Department of Pharmacology and Therapeutics, University of Florida, PO Box 100267, Gainesville, FL 32610, USA
| | - Ariell M Joiner
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Lian Zhang
- Department of Pharmacology and Therapeutics, University of Florida, PO Box 100267, Gainesville, FL 32610, USA
| | - Jorge Iñiguez-Lluhí
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Jeffrey R Martens
- Department of Pharmacology and Therapeutics, University of Florida, PO Box 100267, Gainesville, FL 32610, USA
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11
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Sahin U, Ferhi O, Jeanne M, Benhenda S, Berthier C, Jollivet F, Niwa-Kawakita M, Faklaris O, Setterblad N, de Thé H, Lallemand-Breitenbach V. Oxidative stress-induced assembly of PML nuclear bodies controls sumoylation of partner proteins. ACTA ACUST UNITED AC 2014; 204:931-45. [PMID: 24637324 PMCID: PMC3998805 DOI: 10.1083/jcb.201305148] [Citation(s) in RCA: 155] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
PML multimerization into nuclear bodies following its oxidation promotes sumoylation and sequestration of partner proteins in these structures. The promyelocytic leukemia (PML) protein organizes PML nuclear bodies (NBs), which are stress-responsive domains where many partner proteins accumulate. Here, we clarify the basis for NB formation and identify stress-induced partner sumoylation as the primary NB function. NB nucleation does not rely primarily on intermolecular interactions between the PML SUMO-interacting motif (SIM) and SUMO, but instead results from oxidation-mediated PML multimerization. Oxidized PML spherical meshes recruit UBC9, which enhances PML sumoylation, allow partner recruitment through SIM interactions, and ultimately enhance partner sumoylation. Intermolecular SUMO–SIM interactions then enforce partner sequestration within the NB inner core. Accordingly, oxidative stress enhances NB formation and global sumoylation in vivo. Some NB-associated sumoylated partners also become polyubiquitinated by RNF4, precipitating their proteasomal degradation. As several partners are protein-modifying enzymes, NBs could act as sensors that facilitate and confer oxidative stress sensitivity not only to sumoylation but also to other post-translational modifications, thereby explaining alterations of stress response upon PML or NB loss.
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Affiliation(s)
- Umut Sahin
- Université Paris Diderot, Sorbonne Paris Cité, Hôpital St. Louis 1, 75475 Paris Cedex 10, France
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12
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Evidence Implicating CCNB1IP1, a RING Domain-Containing Protein Required for Meiotic Crossing Over in Mice, as an E3 SUMO Ligase. Genes (Basel) 2014; 1:440-51. [PMID: 21779533 PMCID: PMC3139512 DOI: 10.3390/genes1030440] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
The RING domain-containing protein CCNB1IP1 (Cyclin B1 Interacting Protein 1) is a putative ubiquitin E3 ligase that is essential for chiasmata formation, and hence fertility, in mice. Previous studies in cultured cells indicated that CCNB1IP1 targets Cyclin B for degradation, thus playing a role in cell cycle regulation. Mice homozygous for a mutant allele (mei4) of Ccnb1ip1 display no detectable phenotype other than meiotic failure from an absence of chiasmata. CCNB1IP1 is not conserved in key model organisms such as yeast and Drosophila, and there are no features of the protein that implicate clear mechanisms for a role in recombination. To gain insight into CCNB1IP1’s function in meiotic cells, we raised a specific antibody and determined that the protein appears in pachynema. This indicates that CCNB1IP1 is involved with crossover intermediate maturation, rather than early (leptotene) specification of a subset of SPO11-induced double strand breaks towards the crossover pathway. Additionally, a yeast 2-hybrid (Y2H) screen revealed that CCNB1IP1 interacts with SUMO2 and a set of proteins enriched for consensus sumoylation sites. The Y2H studies, combined with scrutiny of CCNB1IP1 domains, implicate this protein as an E3 ligase of the sumoylation cascade. We hypothesize CCNB1IP1 represents a novel meiosis-specific SUMO E3 ligase critical to resolution of recombination intermediates into mature chiasmata.
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13
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Mascle XH, Lussier-Price M, Cappadocia L, Estephan P, Raiola L, Omichinski JG, Aubry M. Identification of a non-covalent ternary complex formed by PIAS1, SUMO1, and UBC9 proteins involved in transcriptional regulation. J Biol Chem 2013; 288:36312-27. [PMID: 24174529 DOI: 10.1074/jbc.m113.486845] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Post-translational modifications with ubiquitin-like proteins require three sequentially acting enzymes (E1, E2, and E3) that must unambiguously recognize each other in a coordinated fashion to achieve their functions. Although a single E2 (UBC9) and few RING-type E3s (PIAS) operate in the SUMOylation system, the molecular determinants regulating the interactions between UBC9 and the RING-type E3 enzymes are still not well defined. In this study we use biochemical and functional experiments to characterize the interactions between PIAS1 and UBC9. Our results reveal that UBC9 and PIAS1 are engaged both in a canonical E2·E3 interaction as well as assembled into a previously unidentified non-covalent ternary complex with SUMO as evidenced by bioluminescence resonance energy transfer, nuclear magnetic resonance spectroscopy, and isothermal titration calorimetry studies. In this ternary complex, SUMO functions as a bridge by forming non-overlapping interfaces with UBC9 and PIAS1. Moreover, our data suggest that phosphorylation of serine residues adjacent to the PIAS1 SUMO-interacting motif favors formation of the non covalent PIAS1·SUMO·UBC9 ternary complex. Finally, our results also indicate that the non-covalent ternary complex is required for the known transcriptional repression activities mediated by UBC9 and SUMO1. Taken together, the data enhance our knowledge concerning the mode of interaction of enzymes of the SUMOylation machinery as well as their role in transcriptional regulation and establishes a framework for investigations of other ubiquitin-like protein systems.
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Affiliation(s)
- Xavier H Mascle
- From the Département de Biochimie, Université de Montréal, C. P. 6128 Succursale Centre-Ville, Montréal, Quebec H3C 3J7, Canada
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14
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Chen M, Zhang W, Lu X, Hoggatt AM, Gunst SJ, Kassab GS, Tune JD, Herring BP. Regulation of 130-kDa smooth muscle myosin light chain kinase expression by an intronic CArG element. J Biol Chem 2013; 288:34647-57. [PMID: 24151072 DOI: 10.1074/jbc.m113.510362] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The mylk1 gene encodes a 220-kDa nonmuscle myosin light chain kinase (MLCK), a 130-kDa smooth muscle MLCK (smMLCK), as well as the non-catalytic product telokin. Together, these proteins play critical roles in regulating smooth muscle contractility. Changes in their expression are associated with many pathological conditions; thus, it is important to understand the mechanisms regulating expression of mylk1 gene transcripts. Previously, we reported a highly conserved CArG box, which binds serum response factor, in intron 15 of mylk1. Because this CArG element is near the promoter that drives transcription of the 130-kDa smMLCK, we examined its role in regulating expression of this transcript. Results show that deletion of the intronic CArG region from a β-galactosidase reporter gene abolished transgene expression in mice in vivo. Deletion of the CArG region from the endogenous mylk1 gene, specifically in smooth muscle cells, decreased expression of the 130-kDa smMLCK by 40% without affecting expression of the 220-kDa MLCK or telokin. This reduction in 130-kDa smMLCK expression resulted in decreased phosphorylation of myosin light chains, attenuated smooth muscle contractility, and a 24% decrease in small intestine length that was associated with a significant reduction of Ki67-positive smooth muscle cells. Overall, these data show that the CArG element in intron 15 of the mylk1 gene is necessary for maximal expression of the 130-kDa smMLCK and that the 130-kDa smMLCK isoform is specifically required to regulate smooth muscle contractility and small intestine smooth muscle cell proliferation.
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Affiliation(s)
- Meng Chen
- From the Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana 46202
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15
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Oxidized DJ-1 inhibits p53 by sequestering p53 from promoters in a DNA-binding affinity-dependent manner. Mol Cell Biol 2012; 33:340-59. [PMID: 23149933 DOI: 10.1128/mcb.01350-12] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
DJ-1 is an oncogene and the causative gene for familial Parkinson's disease. Although the oxidative status of DJ-1 at cysteine 106 (C106) is thought to affect all of the activities of DJ-1 and excess oxidation leads to the onset of various diseases, the precise molecular mechanisms underlying the effects of oxidation of DJ-1 on protein-protein interactions of DJ-1 remain unclear. In this study, we found that DJ-1 bound to the DNA-binding region of p53 in a manner dependent on the oxidation of C106. Of the p53 target genes, the expression level and promoter activity of the DUSP1 gene, but not those of the p21 gene, were increased in H(2)O(2)-treated DJ-1(-/-) cells and were decreased in wild-type DJ-1- but not C106S DJ-1-transfected H1299 cells through sequestration of p53 from the DUSP1 promoter by DJ-1. DUSP1 downregulated by oxidized DJ-1 activated extracellular signal-regulated kinase (ERK) and decreased apoptosis. The DUSP1 and p21 promoters harbor nonconsensus and consensus p53 recognition sequences, respectively, which have low affinity and high affinity for p53. However, DJ-1 inhibited p21 promoter activity exhibited by p53 mutants harboring low DNA-binding affinity but not by wild-type p53. These results indicate that DJ-1 inhibits the expression of p53 target genes and depend on p53 DNA-binding affinity and oxidation of DJ-1 C106.
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16
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Li Y, Zhang Q, Wei Q, Zhang Y, Ling K, Hu J. SUMOylation of the small GTPase ARL-13 promotes ciliary targeting of sensory receptors. J Cell Biol 2012; 199:589-98. [PMID: 23128241 PMCID: PMC3494855 DOI: 10.1083/jcb.201203150] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Accepted: 10/10/2012] [Indexed: 11/22/2022] Open
Abstract
Primary cilia serve as cellular antenna for various sensory signaling pathways. However, how the sensory receptors are properly targeted to the ciliary surface remains poorly understood. Here, we show that UBC-9, the sole E2 small ubiquitin-like modifier (SUMO)-conjugating enzyme, physically interacts with and SUMOylates the C terminus of small GTPase ARL-13, the worm orthologue of ARL13B that mutated in ciliopathy Joubert syndrome. Mutations that totally abolish the SUMOylation of ARL-13 do not affect its established role in ciliogenesis, but fail to regulate the proper ciliary targeting of various sensory receptors and consequently compromise the corresponding sensory functions. Conversely, constitutively SUMOylated ARL-13 fully rescues all ciliary defects of arl-13-null animals. Furthermore, SUMOylation modification of human ARL13B is required for the ciliary entry of polycystin-2, the protein mutated in autosomal dominant polycystic kidney disease. Our data reveal a novel but conserved role for the SUMOylation modification of ciliary small GTPase ARL13B in specifically regulating the proper ciliary targeting of various sensory receptors.
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Affiliation(s)
- Yujie Li
- Department of Biochemistry and Molecular Biology, Division of Nephrology and Hypertension, and Department of Internal Medicine, Mayo Translational Polycystic Kidney Disease (PKD) Center, Mayo Clinic, Rochester, MN 55905
| | - Qing Zhang
- Department of Biochemistry and Molecular Biology, Division of Nephrology and Hypertension, and Department of Internal Medicine, Mayo Translational Polycystic Kidney Disease (PKD) Center, Mayo Clinic, Rochester, MN 55905
| | - Qing Wei
- Department of Biochemistry and Molecular Biology, Division of Nephrology and Hypertension, and Department of Internal Medicine, Mayo Translational Polycystic Kidney Disease (PKD) Center, Mayo Clinic, Rochester, MN 55905
| | - Yuxia Zhang
- Department of Biochemistry and Molecular Biology, Division of Nephrology and Hypertension, and Department of Internal Medicine, Mayo Translational Polycystic Kidney Disease (PKD) Center, Mayo Clinic, Rochester, MN 55905
| | - Kun Ling
- Department of Biochemistry and Molecular Biology, Division of Nephrology and Hypertension, and Department of Internal Medicine, Mayo Translational Polycystic Kidney Disease (PKD) Center, Mayo Clinic, Rochester, MN 55905
| | - Jinghua Hu
- Department of Biochemistry and Molecular Biology, Division of Nephrology and Hypertension, and Department of Internal Medicine, Mayo Translational Polycystic Kidney Disease (PKD) Center, Mayo Clinic, Rochester, MN 55905
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17
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Braun KR, DeWispelaere AM, Bressler SL, Fukai N, Kenagy RD, Chen L, Clowes AW, Kinsella MG. Inhibition of PDGF-B induction and cell growth by syndecan-1 involves the ubiquitin and SUMO-1 ligase, Topors. PLoS One 2012; 7:e43701. [PMID: 22912899 PMCID: PMC3422340 DOI: 10.1371/journal.pone.0043701] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2012] [Accepted: 07/23/2012] [Indexed: 01/14/2023] Open
Abstract
Syndecans are receptors for soluble ligands, including heparin-binding growth factors, and matrix proteins. However, intracellular targets of syndecan-1 (Sdc-1)-mediated signaling are not fully understood. A yeast two-hybrid protein interaction screening of a mouse embryo library identified the ubiquitin and SUMO-1 E3 ligase, Topors, as a novel ligand of the Sdc-1 cytoplasmic domain (S1CD), a finding confirmed by ligand blotting and co-precipitation with Sdc-1 from cell lysates. Deletion mutagenesis identified an 18-amino acid sequence of Topors required for the interaction with the S1CD. By immunohistochemistry, Topors and Sdc-1 co-localized near the cell periphery in normal murine mammary gland (NMuMG) cells in vitro and in mouse embryonic epithelia in vivo. Finally, siRNA-mediated knockdown of Topors demonstrated that Topors is a growth promoter for murine arterial smooth muscle cells and is required for the inhibitory effect of Sdc-1 on cell growth and platelet-derived growth factor-B induction. These data suggest a novel mechanism for the inhibitory effects of Sdc-1 on cell growth that involves the interaction between the cytoplasmic domain of Sdc-1 and the SUMO-1 E3 ligase, Topors.
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Affiliation(s)
- Kathleen R. Braun
- Benaroya Research Institute at Virginia Mason, Seattle, Washington, United States of America
| | - Allison M. DeWispelaere
- Benaroya Research Institute at Virginia Mason, Seattle, Washington, United States of America
| | - Steven L. Bressler
- Benaroya Research Institute at Virginia Mason, Seattle, Washington, United States of America
| | - Nozomi Fukai
- Department of Surgery, University of Washington, Seattle, Washington, United States of America
| | - Richard D. Kenagy
- Department of Surgery, University of Washington, Seattle, Washington, United States of America
| | - Lihua Chen
- Department of Surgery, University of Washington, Seattle, Washington, United States of America
| | - Alexander W. Clowes
- Department of Surgery, University of Washington, Seattle, Washington, United States of America
| | - Michael G. Kinsella
- Benaroya Research Institute at Virginia Mason, Seattle, Washington, United States of America
- * E-mail:
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18
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Praefcke GJK, Hofmann K, Dohmen RJ. SUMO playing tag with ubiquitin. Trends Biochem Sci 2011; 37:23-31. [PMID: 22018829 DOI: 10.1016/j.tibs.2011.09.002] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Revised: 09/13/2011] [Accepted: 09/15/2011] [Indexed: 10/16/2022]
Abstract
In addition to being structurally related, the protein modifiers ubiquitin and SUMO (small ubiquitin-related modifier), share a multitude of functional interrelations. These include the targeting of the same attachment sites in certain substrates, and SUMO-dependent ubiquitylation in others. Notably, several cellular processes, including the targeting of repair machinery to DNA damage sites, require the sequential sumoylation and ubiquitylation of distinct substrates. Some proteins promote both modifications. By contrast, the activity of some enzymes that control either sumoylation or ubiquitylation is regulated by the respective other modification. In this review, we summarize recent findings regarding intersections between SUMO and ubiquitin that influence genome stability and cell growth and which are relevant in pathogen resistance and cancer treatment.
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Affiliation(s)
- Gerrit J K Praefcke
- Center for Molecular Medicine Cologne, Institute for Genetics, University of Cologne, Cologne Biocenter, Zülpicher Straße 47a, D-50674 Cologne, Germany
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19
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Nuclear structure and chromosome segregation in Drosophila male meiosis depend on the ubiquitin ligase dTopors. Genetics 2011; 189:779-93. [PMID: 21900273 DOI: 10.1534/genetics.111.133819] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In many organisms, homolog pairing and synapsis at meiotic prophase depend on interactions between chromosomes and the nuclear membrane. Male Drosophila lack synapsis, but nonetheless, their chromosomes closely associate with the nuclear periphery at prophase I. To explore the functional significance of this association, we characterize mutations in nuclear blebber (nbl), a gene required for both spermatocyte nuclear shape and meiotic chromosome transmission. We demonstrate that nbl corresponds to dtopors, the Drosophila homolog of the mammalian dual ubiquitin/small ubiquitin-related modifier (SUMO) ligase Topors. We show that mutations in dtopors cause abnormalities in lamin localizations, centriole separation, and prophase I chromatin condensation and also cause anaphase I bridges that likely result from unresolved homolog connections. Bridge formation does not require mod(mdg4) in meiosis, suggesting that bridges do not result from misregulation of the male homolog conjunction complex. At the ultrastructural level, we observe disruption of nuclear shape, an uneven perinuclear space, and excess membranous structures. We show that dTopors localizes to the nuclear lamina at prophase, and also transiently to intranuclear foci. As a role of dtopors at gypsy insulator has been reported, we also asked whether these new alleles affected expression of the gypsy-induced mutation ct(6) and found that it was unaltered in dtopors homozygotes. Our results indicate that dTopors is required for germline nuclear structure and meiotic chromosome segregation, but in contrast, is not necessary for gypsy insulator function. We suggest that dtopors plays a structural role in spermatocyte lamina that is critical for multiple aspects of meiotic chromosome transmission.
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20
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Chakarova CF, Khanna H, Shah AZ, Patil SB, Sedmak T, Murga-Zamalloa CA, Papaioannou MG, Nagel-Wolfrum K, Lopez I, Munro P, Cheetham M, Koenekoop RK, Rios RM, Matter K, Wolfrum U, Swaroop A, Bhattacharya SS. TOPORS, implicated in retinal degeneration, is a cilia-centrosomal protein. Hum Mol Genet 2010; 20:975-87. [PMID: 21159800 DOI: 10.1093/hmg/ddq543] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
We recently reported that mutations in the widely expressed nuclear protein TOPORS (topoisomerase I-binding arginine/serine rich) are associated with autosomal dominant retinal degeneration. However, the precise localization and a functional role of TOPORS in the retina remain unknown. Here, we demonstrate that TOPORS is a novel component of the photoreceptor sensory cilium, which is a modified primary cilium involved with polarized trafficking of proteins. In photoreceptors, TOPORS localizes primarily to the basal bodies of connecting cilium and in the centrosomes of cultured cells. Morpholino-mediated silencing of topors in zebrafish embryos demonstrates in another species a comparable retinal problem as seen in humans, resulting in defective retinal development and failure to form outer segments. These defects can be rescued by mRNA encoding human TOPORS. Taken together, our data suggest that TOPORS may play a key role in regulating primary cilia-dependent photoreceptor development and function. Additionally, it is well known that mutations in other ciliary proteins cause retinal degeneration, which may explain why mutations in TOPORS result in the same phenotype.
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21
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Sonne SB, Perrett RM, Nielsen JE, Baxter MA, Kristensen DM, Leffers H, Hanley NA, Rajpert-De-Meyts E. Analysis of SOX2 expression in developing human testis and germ cell neoplasia. THE INTERNATIONAL JOURNAL OF DEVELOPMENTAL BIOLOGY 2010; 54:755-60. [PMID: 19876845 DOI: 10.1387/ijdb.082668ss] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The transcriptional regulators of pluripotency, POU5F1 (OCT4), NANOG and SOX2, are highly expressed in embryonal carcinoma (EC). In contrast to OCT4 and NANOG, SOX2 has not been demonstrated in the early human germ cell lineage or carcinoma in situ (CIS), the precursor for testicular germ cell tumours (TGCTs). Here, we have analysed SOX2 expression in CIS and overt TGCTs, as well as normal second and third trimester fetal, prepubertal and adult testes by in situ hybridisation and immunohistochemistry using three different antibodies. In contrast to earlier studies, we detected SOX2 mRNA in most CIS cells. We also detected speckled nuclear SOX2 immunoreactivity in CIS cells with one primary antibody, which was not apparent with other primary antibodies. The results demonstrate SOX2 gene expression in CIS for the first time and raise the possibility of post-transcriptional regulation, most likely sumoylation as a mechanism for limiting SOX2 action in these cells.
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Affiliation(s)
- Si B Sonne
- University Department of Growth and Reproduction, Rigshospitalet, Copenhagen, Denmark
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22
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Abstract
The post-translational modification SUMOylation is a major regulator of protein function that plays an important role in a wide range of cellular processes. SUMOylation involves the covalent attachment of a member of the SUMO (small ubiquitin-like modifier) family of proteins to lysine residues in specific target proteins via an enzymatic cascade analogous to, but distinct from, the ubiquitination pathway. There are four SUMO paralogues and an increasing number of proteins are being identified as SUMO substrates. However, in many cases little is known about how SUMOylation of these targets is regulated. Compared with the ubiquitination pathway, relatively few components of the conjugation machinery have been described and the processes that specify individual SUMO paralogue conjugation to defined substrate proteins are an active area of research. In the present review, we briefly describe the SUMOylation pathway and present an overview of the recent findings that are beginning to identify some of the mechanisms that regulate protein SUMOylation.
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Affiliation(s)
- Kevin A. Wilkinson
- Medical Research Council Centre for Synaptic Plasticity, Department of Anatomy, School of Medical Sciences, University of Bristol, University Walk, Bristol BS8 1TD, U.K
| | - Jeremy M. Henley
- Medical Research Council Centre for Synaptic Plasticity, Department of Anatomy, School of Medical Sciences, University of Bristol, University Walk, Bristol BS8 1TD, U.K
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23
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Selmer KK, Grøndahl J, Riise R, Brandal K, Braaten Ø, Bragadottir R, Undlien DE. Autosomal dominant pericentral retinal dystrophy caused by a novel missense mutation in the TOPORS gene. Acta Ophthalmol 2010; 88:323-8. [PMID: 19183411 DOI: 10.1111/j.1755-3768.2008.01465.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
PURPOSE This study aimed to identify the genetic cause of autosomal dominant pericentral retinal dystrophy (adPRD) in a large Norwegian family with 35 affected members. METHODS The family was characterized by clinical ophthalmological examination along with fundus photography, dark adaptometry and electroretinography. We performed a genome-wide linkage analysis followed by sequencing of a candidate gene to identify the mutation causing the disease. RESULTS The ophthalmological examinations revealed an atypical form of retinitis pigmentosa (RP), which we prefer to call adPRD. Compared with classical RP, this phenotype has a favourable prognosis. Linkage analysis showed a linkage peak covering the most recently reported adRP gene TOPORS. This gene was sequenced in 19 family members and a novel missense mutation, c.1205a>c, resulting in an amino acid substitution p.Q402P, was detected in all affected members. The mutation showed complete co-segregation with the disease in this family, with a LOD score of 7.3. It is located in a highly conserved region and alignment with the appropriate DNA sequence from other species shows complete conservation of this amino acid. The mutation was not detected in 207 healthy, unrelated controls of Norwegian origin. CONCLUSIONS We present a novel mutation in the TOPORS gene co-segregating with a distinct phenotype of adPRD in a large Norwegian family.
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Park HJ, Zheng H, Kulkarni D, Kerrigan J, Pungaliya P, Saleem A, Rubin EH. Identification of phosphorylation sites of TOPORS and a role for serine 98 in the regulation of ubiquitin but not SUMO E3 ligase activity. Biochemistry 2009; 47:13887-96. [PMID: 19053840 DOI: 10.1021/bi801904q] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
TOPORS is the first example of a protein that possesses both ubiquitin and SUMO E3 ligase activity. The ubiquitination activity maps to a conserved RING domain in the N-terminal region of the protein, which is not required for sumoylation activity. Similar to other E3 ligases, it is likely that the ubiquitin and sumoylation activities of TOPORS are regulated by post-translational modifications. Therefore, we employed mass spectrometry to identify post-translational modifications of TOPORS. Several putative phosphorylated regions were identified in conserved regions of the protein. We investigated the role of phosphorylation of serine 98, which is adjacent to the RING domain, in both cells and in vitro. Mutation of serine 98 to aspartic acid resulted in an increase in the ubiquitin ligase activity of TOPORS both in cells and in vitro. In addition, this mutation increased the binding of TOPORS to the E2 enzyme UbcH5a both in vitro and in cells. Conversely, a phospho-deficient mutant (S98A) exhibited little change in ubiquitin ligase activity compared to wild-type TOPORS, both in cells and in vitro. Neither of the mutants affected the localization of TOPORS to punctate nuclear regions. In addition, neither mutant affected the SUMO ligase activity of TOPORS in cells or in vitro. Molecular modeling studies support a role for serine 98 in regulating TOPORS-E2 interactions. Our findings indicate that phosphorylation of serine 98 regulates the ubiquitin but not the SUMO ligase activity of TOPORS, consistent with a potential binary switch function for TOPORS in protein ubiquitination versus sumoylation.
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Affiliation(s)
- Hye-Jin Park
- Departments of Pharmacology and Medicine, The Cancer Institute of New Jersey, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, 195 Little Albany Street, New Brunswick, New Jersey 08901, USA
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25
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Chakarova CF, Papaioannou MG, Khanna H, Lopez I, Waseem N, Shah A, Theis T, Friedman J, Maubaret C, Bujakowska K, Veraitch B, Abd El-Aziz MM, Prescott DQ, Parapuram SK, Bickmore WA, Munro PMG, Gal A, Hamel CP, Marigo V, Ponting CP, Wissinger B, Zrenner E, Matter K, Swaroop A, Koenekoop RK, Bhattacharya SS. Mutations in TOPORS cause autosomal dominant retinitis pigmentosa with perivascular retinal pigment epithelium atrophy. Am J Hum Genet 2007; 81:1098-103. [PMID: 17924349 DOI: 10.1086/521953] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2007] [Accepted: 07/17/2007] [Indexed: 11/03/2022] Open
Abstract
We report mutations in the gene for topoisomerase I-binding RS protein (TOPORS) in patients with autosomal dominant retinitis pigmentosa (adRP) linked to chromosome 9p21.1 (locus RP31). A positional-cloning approach, together with the use of bioinformatics, identified TOPORS (comprising three exons and encoding a protein of 1,045 aa) as the gene responsible for adRP. Mutations that include an insertion and a deletion have been identified in two adRP-affected families--one French Canadian and one German family, respectively. Interestingly, a distinct phenotype is noted at the earlier stages of the disease, with an unusual perivascular cuff of retinal pigment epithelium atrophy, which was found surrounding the superior and inferior arcades in the retina. TOPORS is a RING domain-containing E3 ubiquitin ligase and localizes in the nucleus in speckled loci that are associated with promyelocytic leukemia bodies. The ubiquitous nature of TOPORS expression and a lack of mutant protein in patients are highly suggestive of haploinsufficiency, rather than a dominant negative effect, as the molecular mechanism of the disease and make rescue of the clinical phenotype amenable to somatic gene therapy.
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26
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Hammer E, Heilbronn R, Weger S. The E3 ligase Topors induces the accumulation of polysumoylated forms of DNA topoisomerase I in vitro and in vivo. FEBS Lett 2007; 581:5418-24. [PMID: 17976381 DOI: 10.1016/j.febslet.2007.10.040] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2007] [Revised: 10/22/2007] [Accepted: 10/22/2007] [Indexed: 11/30/2022]
Abstract
Human Topors has originally been identified as binding partner of p53 and DNA topoisomerase I (TOP1). It can function as both an ubiquitin and SUMO-1 E3 ligase for p53. Here we demonstrate that Topors enhances the formation of high-molecular weight SUMO-1 conjugates of TOP1 in a reconstituted in vitro system and also in human osteosarcoma cells, similar to treatment with CPT. In contrast to the situation observed with p53, overall sumoylation levels were rather unaffected. Experiments with TOP1 point mutants strongly suggest that the high-molecular weight conjugates represent SUMO-1 chains formed on a limited number of SUMO-1 acceptor sites.
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Affiliation(s)
- Eva Hammer
- Institute of Virology, Charité Campus Benjamin Franklin, Free University of Berlin, Hindenburgdamm 27, 12203 Berlin, Germany
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27
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Abstract
Mutations or deletions of the TRPS1 gene on human chromosome 8q.24.1 cause the tricho-rhino-phalangeal syndromes (TRPS), which are characterized by craniofacial and skeletal malformations. The gene encodes a transcription factor that functions as a repressor for GATA-mediated transcription. The activity of transcription factors is often controlled by posttranslational modifications. We show here that TRPS1 is SUMOylated at multiple sites, both in vivo and in vitro, through interaction with UBC9. Overexpression of wild-type UBC9 enhances TRPS1-mediated transcriptional repression. In contrast, a SUMOylation-deficient UBC9 mutant, which nevertheless still binds TRPS1, has no effect. Of the five potential TRPS1 SUMO-target sites, which were predicted based on a minimal SUMOylation consensus sequence (MCS), two are located within the C-terminal repression domain (RD) at lysine residues 1192 (termed S4) and 1201 (S5). S5 was identified as the major acceptor site within this region, and a point mutation of S5 strongly decreases TRPS1-RD-mediated transcriptional repression. Additional mutation of S4 results in abrogation of SUMOylation at the TRPS1-RD and almost complete loss of the repressive properties of TRPS1. These results identify SUMOylation at the TRPS1-RD as a major mechanism that regulates the function of TRPS1.
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Affiliation(s)
- Frank J Kaiser
- Institut für Humangenetik, Universitätsklinikum Essen, D-45122 Essen, Germany.
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28
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Weger S, Hammer E, Götz A, Heilbronn R. Identification of a cytoplasmic interaction partner of the large regulatory proteins Rep78/Rep68 of adeno-associated virus type 2 (AAV-2). Virology 2007; 362:192-206. [PMID: 17239418 DOI: 10.1016/j.virol.2006.12.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2006] [Revised: 11/29/2006] [Accepted: 12/06/2006] [Indexed: 11/28/2022]
Abstract
Through yeast two-hybrid analysis and coimmunoprecipitation studies, we have identified a novel cellular AAV-2 Rep78/Rep68 interaction partner located predominantly in the cytoplasm. In public databases, it has been assigned as KCTD5, because of a region of high similarity to the cytoplasmic tetramerization domain of voltage-gated potassium channels. Whereas Rep/KCTD5 interaction relied on the region surrounding the Rep nuclear localization signal, nuclear accumulation of Rep was not required. Wildtype Rep78/Rep68 proteins induced the translocation of large portions of KCTD5 into the nucleus pointing to functional interactions both in the cytoplasm and the nucleus. In line with an anticipated functional interference in the cytoplasm, KCTD5 overexpression completely abrogated Rep68-mediated posttranscriptional activation of a HIV-LTR driven luciferase reporter gene. Our study expands the panel of already identified nuclear Rep interaction partners to a cytoplasmic protein, which raises the awareness that important steps in the AAV life cycle may be regulated in this compartment.
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Affiliation(s)
- Stefan Weger
- Institut für Virologie, Charité Campus Benjamin Franklin, Freie Universität Berlin, Hindenburgdamm 27, 12203 Berlin, Germany.
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29
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Lin DY, Huang YS, Jeng JC, Kuo HY, Chang CC, Chao TT, Ho CC, Chen YC, Lin TP, Fang HI, Hung CC, Suen CS, Hwang MJ, Chang KS, Maul GG, Shih HM. Role of SUMO-interacting motif in Daxx SUMO modification, subnuclear localization, and repression of sumoylated transcription factors. Mol Cell 2006; 24:341-54. [PMID: 17081986 DOI: 10.1016/j.molcel.2006.10.019] [Citation(s) in RCA: 329] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2006] [Revised: 08/23/2006] [Accepted: 10/16/2006] [Indexed: 12/15/2022]
Abstract
Small ubiquitin-like modifier (SUMO) modification has emerged as an important posttranslational control of protein functions. Daxx, a transcriptional corepressor, was reported to repress the transcriptional potential of several transcription factors and target to PML oncogenic domains (PODs) via SUMO-dependent interactions. The mechanism by which Daxx binds to sumoylated factors mediating transcriptional and subnuclear compartmental regulation remains unclear. Here, we define a SUMO-interacting motif (SIM) within Daxx and show it to be crucial for targeting Daxx to PODs and for transrepression of several sumoylated transcription factors, including glucocorticoid receptor (GR). In addition, the capability of Daxx SIM to bind SUMO also controls Daxx sumoylation. We further demonstrate that arsenic trioxide-induced sumoylation of PML correlates with a change of endogenous Daxx partitioning from GR-regulated gene promoter to PODs and a relief of Daxx repression on GR target gene expression. Our results provide mechanistic insights into Daxx in SUMO-dependent transcriptional control and subnuclear compartmentalization.
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Affiliation(s)
- Ding-Yen Lin
- Institute of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan, Republic of China
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30
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Capelson M, Corces VG. SUMO conjugation attenuates the activity of the gypsy chromatin insulator. EMBO J 2006; 25:1906-14. [PMID: 16628226 PMCID: PMC1456934 DOI: 10.1038/sj.emboj.7601068] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2005] [Accepted: 03/08/2006] [Indexed: 02/08/2023] Open
Abstract
Chromatin insulators have been implicated in the establishment of independent gene expression domains and in the nuclear organization of chromatin. Post-translational modification of proteins by Small Ubiquitin-like Modifier (SUMO) has been reported to regulate their activity and subnuclear localization. We present evidence suggesting that two protein components of the gypsy chromatin insulator of Dorsophila melanogaster, Mod(mdg4)2.2 and CP190, are sumoylated, and that SUMO is associated with a subset of genomic insulator sites. Disruption of the SUMO conjugation pathway improves the enhancer-blocking function of a partially active insulator, indicating that SUMO modification acts to regulate negatively the activity of the gypsy insulator. Sumoylation does not affect the ability of CP190 and Mod(mdg4)2.2 to bind chromatin, but instead appears to regulate the nuclear organization of gypsy insulator complexes. The results suggest that long-range interactions of insulator proteins are inhibited by sumoylation and that the establishment of chromatin domains can be regulated by SUMO conjugation.
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Affiliation(s)
- Maya Capelson
- Department of Biology, Johns Hopkins University, Baltimore, MD, USA
| | - Victor G Corces
- Department of Biology, Johns Hopkins University, Baltimore, MD, USA
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31
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Hecker CM, Rabiller M, Haglund K, Bayer P, Dikic I. Specification of SUMO1- and SUMO2-interacting motifs. J Biol Chem 2006; 281:16117-27. [PMID: 16524884 DOI: 10.1074/jbc.m512757200] [Citation(s) in RCA: 402] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
SUMO proteins are ubiquitin-related modifiers implicated in the regulation of gene transcription, cell cycle, DNA repair, and protein localization. The molecular mechanisms by which the sumoylation of target proteins regulates diverse cellular functions remain poorly understood. Here we report isolation and characterization of SUMO1- and SUMO2-binding motifs. Using yeast two-hybrid system, bioinformatics, and NMR spectroscopy we define a common SUMO-interacting motif (SIM) and map its binding surfaces on SUMO1 and SUMO2. This motif forms a beta-strand that could bind in parallel or antiparallel orientation to the beta2-strand of SUMO due to the environment of the hydrophobic core. A negative charge imposed by a stretch of neighboring acidic amino acids and/or phosphorylated serine residues determines its specificity in binding to distinct SUMO paralogues and can modulate the spatial orientation of SUMO-SIM interactions.
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Affiliation(s)
- Christina-Maria Hecker
- Institute for Biochemistry II, Goethe University Medical School, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany
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32
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Weger S, Hammer E, Heilbronn R. Topors acts as a SUMO-1 E3 ligase for p53 in vitro and in vivo. FEBS Lett 2005; 579:5007-12. [PMID: 16122737 DOI: 10.1016/j.febslet.2005.07.088] [Citation(s) in RCA: 122] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2005] [Revised: 07/13/2005] [Accepted: 07/18/2005] [Indexed: 12/22/2022]
Abstract
Human Topors, which was originally identified as cellular binding partner of DNA topoisomerase I and of p53, has recently been shown to function as an ubiquitin E3 ligase for p53 in a manner dependent on its N'-terminally located RING finger. Here, we demonstrate that Topors also enhances the conjugation of the small ubiquitin-like modifier 1 (SUMO-1) to p53 in vivo and in a reconstituted in vitro system. The Topors SUMO-1 E3 ligase activity does not depend upon its RING finger motif. In HeLa cells, Topors induced p53 sumoylation was accompanied by an increase in endogenous p53 protein levels. Furthermore, Topors enhances the sumoylation of a variety of other, yet unidentified, cellular proteins.
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Affiliation(s)
- Stefan Weger
- Institute of Infectious Diseases, Department of Virology, Charité Campus Benjamin Franklin, Free University of Berlin, Hindenburgdamm 27, 12203 Berlin, Germany.
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33
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Long J, Zuo D, Park M. Pc2-mediated Sumoylation of Smad-interacting Protein 1 Attenuates Transcriptional Repression of E-cadherin. J Biol Chem 2005; 280:35477-89. [PMID: 16061479 DOI: 10.1074/jbc.m504477200] [Citation(s) in RCA: 119] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Epithelial-mesenchymal transition (EMT) is important in embryonic development and tumorigenesis. Smad-interacting protein 1 (SIP1) can induce EMT by repressing the transcription of E-cadherin through recruitment of the corepressor C-terminal-binding protein (CtBP). How the activity of SIP1 is regulated still remains unclear. Here we show in vivo and in vitro that SIP1 is covalently modified by sumoylation at two conserved sites, Lys391 and Lys866. The polycomb protein Pc2, but not the PIAS (protein inhibitor of activated STAT) family proteins, acts as a Small ubiquitin-like modifier E3 ligase for SIP1. Sumoylation of SIP1 does not affect its subcellular localization, but regulates its transcriptional activity. Compared with the wild-type, a SIP1 sumoylation null mutant shows more potent repression on E-cadherin transcription but similar repression on two transforming growth factor-beta-responsive reporter genes and comparable activation on vitamin D3 receptor transcription. Coexpression of SIP1 with Pc2 can partially relieve E-cadherin repression by SIP1. We further show that SIP1 sumoylation disrupts the recruitment of CtBP. Thus SIP1 sumoylation regulates its transcriptional activity in a promoter context-dependent manner and may represent an important intervention target to modulate EMT in tumorigenesis.
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MESH Headings
- Amino Acid Motifs
- Amino Acid Sequence
- Animals
- Binding Sites
- COS Cells
- Cadherins/metabolism
- Cell Line
- Cell Nucleus/metabolism
- Chlorocebus aethiops
- DNA, Complementary/metabolism
- Dogs
- Genes, Reporter
- Glutathione Transferase/metabolism
- Homeodomain Proteins/metabolism
- Humans
- Immunoprecipitation
- Ligands
- Ligases
- Luciferases/metabolism
- Lysine/chemistry
- Microscopy, Confocal
- Microscopy, Fluorescence
- Mink
- Models, Biological
- Molecular Sequence Data
- Mutation
- Polycomb-Group Proteins
- Promoter Regions, Genetic
- Protein Binding
- Protein Structure, Tertiary
- Receptors, Calcitriol/metabolism
- Repressor Proteins/metabolism
- Repressor Proteins/physiology
- Sequence Homology, Amino Acid
- Transcription, Genetic
- Transcriptional Activation
- Transfection
- Ubiquitin-Protein Ligases
- Zinc Finger E-box Binding Homeobox 2
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Affiliation(s)
- Jianyin Long
- Molecular Oncology Group, McGill University, Montréal, Québec H3A 1A1, Canada
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34
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Lin L, Ozaki T, Takada Y, Kageyama H, Nakamura Y, Hata A, Zhang JH, Simonds WF, Nakagawara A, Koseki H. topors, a p53 and topoisomerase I-binding RING finger protein, is a coactivator of p53 in growth suppression induced by DNA damage. Oncogene 2005; 24:3385-96. [PMID: 15735665 DOI: 10.1038/sj.onc.1208554] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The RING family zinc-finger protein topors (topoisomerase I-binding protein) binds not only topoisomerase I, but also p53 and the AAV-2 Rep78/68 proteins. topors maps to human chromosome 9p21, which contains candidate tumor suppressor genes implicated in small cell lung cancers. In this study, we isolated the murine counterpart of topors and investigated its impact on p53 function. The deduced amino-acid sequence of mouse topors exhibits extensive similarity to human topors. Overexpressed myc-tagged topors associates with and stabilizes p53, and enhances the p53-dependent transcriptional activities of p21(Waf1), MDM2 and Bax promoters and elevates endogenous p21(Waf1) mRNA levels. Overexpression of topors consequently results in the suppression of cell growth by cell cycle arrest and/or by the induction of apoptosis. Taken together, these studies identify topors as a positive regulator of p53. The expression of topors is induced by exposure to the genotoxic reagents cisplatin and camptothecin, a DNA topoisomerase I inhibitor. We therefore postulate that topors mediates p53-dependent cellular responses induced by DNA damage, suggesting its physiological role as a tumor suppressor.
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Affiliation(s)
- Ling Lin
- Department of Molecular Embryology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan
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35
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Abstract
SUMO (small ubiquitin-related modifier) family proteins are not only structurally but also mechanistically related to ubiquitin in that they are posttranslationally attached to other proteins. As ubiquitin, SUMO is covalently linked to its substrates via amide (isopeptide) bonds formed between its C-terminal glycine residue and the epsilon-amino group of internal lysine residues. The enzymes involved in the reversible conjugation of SUMO are similar to those mediating the ubiquitin conjugation. Since its discovery in 1996, SUMO has received a high degree of attention because of its intriguing and essential functions, and because its substrates include a variety of biomedically important proteins such as tumor suppressor p53, c-jun, PML and huntingtin. SUMO modification appears to play important roles in diverse processes such as chromosome segregation and cell division, DNA replication and repair, nuclear protein import, protein targeting to and formation of certain subnuclear structures, and the regulation of a variety of processes including the inflammatory response in mammals and the regulation of flowering time in plants.
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Affiliation(s)
- R Jürgen Dohmen
- Institute for Genetics, University of Cologne, Zülpicher Str. 47, D-50674 Cologne, Germany.
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36
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Weger S, Hammer E, Heilbronn R. SUMO-1 modification regulates the protein stability of the large regulatory protein Rep78 of adeno associated virus type 2 (AAV-2). Virology 2004; 330:284-94. [PMID: 15527853 DOI: 10.1016/j.virol.2004.09.028] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2004] [Revised: 09/09/2004] [Accepted: 09/21/2004] [Indexed: 12/20/2022]
Abstract
The large Rep proteins Rep78 and Rep68 of the helper-dependent adeno associated virus type 2 (AAV-2) are essential for both site-specific integration of AAV DNA in the absence of helpervirus and productive AAV replication in the presence of helpervirus. We have identified UBC9, the E2 conjugating enzyme for the small ubiquitin-related polypeptide SUMO-1, as binding partner of the large Rep proteins in yeast two-hybrid analysis and in GST pulldown assays. Modification of the large Rep proteins with SUMO-1 could be demonstrated in immunoblot analysis and in immunoprecipitations, with the lysine residue at amino acid position 84 serving as the major attachment site. The largely sumolation-deficient Rep78 lysine to arginine point mutant showed a strongly reduced half-life as compared to the wild-type protein. This finding implicates a role for sumolation in the regulation of Rep78 protein stability that is assumed to be critical for the establishment and maintenance of AAV latency.
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Affiliation(s)
- Stefan Weger
- Institut für Infektionsmedizin, Abteilung Virologie, Charité Campus Benjamin Franklin, Freie Universität Berlin, 12203 Berlin, Germany.
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37
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Hilgarth RS, Murphy LA, Skaggs HS, Wilkerson DC, Xing H, Sarge KD. Regulation and Function of SUMO Modification. J Biol Chem 2004; 279:53899-902. [PMID: 15448161 DOI: 10.1074/jbc.r400021200] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Affiliation(s)
- Roland S Hilgarth
- Department of Molecular and Cellular Biochemistry and Graduate Center for Toxicology, University of Kentucky, Lexington, Kentucky 40536, USA
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38
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Saleem A, Dutta J, Malegaonkar D, Rasheed F, Rasheed Z, Rajendra R, Marshall H, Luo M, Li H, Rubin EH. The topoisomerase I- and p53-binding protein topors is differentially expressed in normal and malignant human tissues and may function as a tumor suppressor. Oncogene 2004; 23:5293-300. [PMID: 15107820 DOI: 10.1038/sj.onc.1207700] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Topors was identified recently as a human protein that binds to topoisomerase I and p53. Topors contains a highly conserved RING domain and localizes in promyelocytic leukemia nuclear bodies. Relatively little is known regarding topors expression patterns or function. We now demonstrate that topors mRNA and protein are widely expressed in normal human tissues. By contrast, topors mRNA and protein levels are decreased or undetectable in colon adenocarcinomas relative to normal colon tissue, and expression of the topors protein is not detectable in several colon cancer cell lines. The human TOPORS gene is located on chromosome 9p21, with loss of heterozygosity in this region frequently observed in several different malignancies. While we were unable to detect loss of heterozygosity of the TOPORS gene in 16 sporadic colon cancer cases, increased methylation of a CpG island in the TOPORS promoter was evident in colon adenocarcinoma specimens relative to matched normal tissues. Additional studies indicate that forced expression of topors inhibits cellular proliferation and is associated with an accumulation of cells in the G(0)/G(1) phase of the cell cycle. This effect is independent of the topors RING domain and maps to a C-terminal region of the protein. These results suggest that topors functions as a negative regulator of cell growth, and possibly as a tumor suppressor.
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Affiliation(s)
- Ahamed Saleem
- Department of Pharmacology, The Cancer Institute of New Jersey, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, New Brunswick, NJ, USA
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39
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Rajendra R, Malegaonkar D, Pungaliya P, Marshall H, Rasheed Z, Brownell J, Liu LF, Lutzker S, Saleem A, Rubin EH. Topors functions as an E3 ubiquitin ligase with specific E2 enzymes and ubiquitinates p53. J Biol Chem 2004; 279:36440-4. [PMID: 15247280 DOI: 10.1074/jbc.c400300200] [Citation(s) in RCA: 148] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The human topoisomerase I- and p53-binding protein topors contains a highly conserved, N-terminal C3HC4-type RING domain that is homologous to the RING domains of known E3 ubiquitin ligases. We demonstrate that topors functions in vitro as a RING-dependent E3 ubiquitin ligase with the E2 enzymes UbcH5a, UbcH5c, and UbcH6 but not with UbcH7, CDC34, or UbcH2b. Additional studies indicate that a conserved tryptophan within the topors RING domain is required for ubiquitination activity. Furthermore, both in vitro and cellular studies implicate p53 as a ubiquitination substrate for topors. Similar to MDM2, overexpression of topors results in a proteasome-dependent decrease in p53 protein expression in a human osteosarcoma cell line. These results are similar to the recent finding that a Drosophila topors orthologue ubiquitinates the Hairy transcriptional repressor and suggest that topors functions as a ubiquitin ligase for multiple transcription factors.
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Affiliation(s)
- Rajeev Rajendra
- Department of Pharmacology, The Cancer Institute of New Jersey, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, New Brunswick, NJ 08901, USA
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