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Mashiko S, Shihab RR, See SB, Schahadat LGZ, Aguiar TFM, Roy P, Porcheray F, Zorn E. Broad responses to chemical adducts shape the natural antibody repertoire in early infancy. SCIENCE ADVANCES 2023; 9:eade8872. [PMID: 37172087 PMCID: PMC10181178 DOI: 10.1126/sciadv.ade8872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Natural antibodies are an integral part of innate humoral immunity yet their development and polyreactive nature are still enigmatic. Here, we show that characteristic monoclonal natural antibodies recognize common chemical moieties or adducts, supporting the view that polyreactive antibodies may often correspond to anti-adduct antibodies. We next examined the development of immunoglobulin M (IgM) and IgG to 81 ubiquitous adducts from birth to old age. Newborn IgM only reacted to a limited number of consensus determinants. This highly restricted neonatal repertoire abruptly diversified around 6 months of age through the development of antibodies to environmental antigens and age-driven epigenetic modifications. In contrast, the IgG repertoire was diverse across the entire life span. Our studies reveal an unrecognized component of humoral immunity directed to common adducts. These findings set the ground for further investigations into the role of anti-adduct B cell responses in homeostatic functions and pathological conditions.
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Affiliation(s)
- Shunya Mashiko
- Columbia Center for Translational Immunology, Columbia University Irving Medical Center, New York, NY, USA
| | - Ronzon R Shihab
- Columbia Center for Translational Immunology, Columbia University Irving Medical Center, New York, NY, USA
| | - Sarah B See
- Columbia Center for Translational Immunology, Columbia University Irving Medical Center, New York, NY, USA
| | - Luca G Z Schahadat
- Columbia Center for Translational Immunology, Columbia University Irving Medical Center, New York, NY, USA
| | - Talita F M Aguiar
- Columbia Center for Translational Immunology, Columbia University Irving Medical Center, New York, NY, USA
| | - Poulomi Roy
- Columbia Center for Translational Immunology, Columbia University Irving Medical Center, New York, NY, USA
| | - Fabrice Porcheray
- Transplant Center, Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Emmanuel Zorn
- Columbia Center for Translational Immunology, Columbia University Irving Medical Center, New York, NY, USA
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2
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Zhou W, Xu C, Dong G, Qiao H, Yang J, Liu H, Ding L, Sun K, Zhao W. Development of phenyltriazole thiol-based derivatives as highly potent inhibitors of DCN1-UBC12 interaction. Eur J Med Chem 2021; 217:113326. [PMID: 33756127 DOI: 10.1016/j.ejmech.2021.113326] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 01/25/2021] [Accepted: 02/20/2021] [Indexed: 11/26/2022]
Abstract
Defective in cullin neddylation 1(DCN1) is a co-E3 ligase that is important for cullin neddylation. Dysregulation of DCN1 highly correlates with the development of various cancers. Herein, from the initial high-throughput screening, a novel hit compound 5a containing a phenyltriazole thiol core (IC50 value of 0.95 μM for DCN1-UBC12 interaction) was discovered. Further structure-based optimization leads to the development of SK-464 (IC50 value of 26 nM). We found that SK-464 not only directly bound to DCN1 in vitro, but also engaged cellular DCN1, suppressed the neddylation of cullin3, and hindered the migration and invasion of two DCN1-overexpressed squamous carcinoma cell lines (KYSE70 and H2170). These findings indicate that SK-464 may be a novel lead compound targeting DCN1-UBC12 interaction.
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Affiliation(s)
- Wenjuan Zhou
- State Key Laboratory of Esophageal Cancer Prevention and Treatment, Key Laboratory of Advanced Pharmaceutical Technology, Ministry of Education of China, Co-innovation Center of Henan Province for New Drug R & D and Preclinical Safety, Zhengzhou University School of Pharmaceutical Sciences and Institute of Drug Discovery & Development, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, Henan, 450001, PR China; Department of Pathology, Oslo University Hospital, Faculty of Medicine, University of Oslo, Oslo, 0379, Norway
| | - Chenhao Xu
- State Key Laboratory of Esophageal Cancer Prevention and Treatment, Key Laboratory of Advanced Pharmaceutical Technology, Ministry of Education of China, Co-innovation Center of Henan Province for New Drug R & D and Preclinical Safety, Zhengzhou University School of Pharmaceutical Sciences and Institute of Drug Discovery & Development, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, Henan, 450001, PR China
| | - Guanjun Dong
- State Key Laboratory of Esophageal Cancer Prevention and Treatment, Key Laboratory of Advanced Pharmaceutical Technology, Ministry of Education of China, Co-innovation Center of Henan Province for New Drug R & D and Preclinical Safety, Zhengzhou University School of Pharmaceutical Sciences and Institute of Drug Discovery & Development, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, Henan, 450001, PR China
| | - Hui Qiao
- State Key Laboratory of Esophageal Cancer Prevention and Treatment, Key Laboratory of Advanced Pharmaceutical Technology, Ministry of Education of China, Co-innovation Center of Henan Province for New Drug R & D and Preclinical Safety, Zhengzhou University School of Pharmaceutical Sciences and Institute of Drug Discovery & Development, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, Henan, 450001, PR China
| | - Jing Yang
- State Key Laboratory of Esophageal Cancer Prevention and Treatment, Key Laboratory of Advanced Pharmaceutical Technology, Ministry of Education of China, Co-innovation Center of Henan Province for New Drug R & D and Preclinical Safety, Zhengzhou University School of Pharmaceutical Sciences and Institute of Drug Discovery & Development, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, Henan, 450001, PR China
| | - Hongmin Liu
- State Key Laboratory of Esophageal Cancer Prevention and Treatment, Key Laboratory of Advanced Pharmaceutical Technology, Ministry of Education of China, Co-innovation Center of Henan Province for New Drug R & D and Preclinical Safety, Zhengzhou University School of Pharmaceutical Sciences and Institute of Drug Discovery & Development, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, Henan, 450001, PR China
| | - Lina Ding
- State Key Laboratory of Esophageal Cancer Prevention and Treatment, Key Laboratory of Advanced Pharmaceutical Technology, Ministry of Education of China, Co-innovation Center of Henan Province for New Drug R & D and Preclinical Safety, Zhengzhou University School of Pharmaceutical Sciences and Institute of Drug Discovery & Development, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, Henan, 450001, PR China.
| | - Kai Sun
- State Key Laboratory of Esophageal Cancer Prevention and Treatment, Key Laboratory of Advanced Pharmaceutical Technology, Ministry of Education of China, Co-innovation Center of Henan Province for New Drug R & D and Preclinical Safety, Zhengzhou University School of Pharmaceutical Sciences and Institute of Drug Discovery & Development, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, Henan, 450001, PR China.
| | - Wen Zhao
- State Key Laboratory of Esophageal Cancer Prevention and Treatment, Key Laboratory of Advanced Pharmaceutical Technology, Ministry of Education of China, Co-innovation Center of Henan Province for New Drug R & D and Preclinical Safety, Zhengzhou University School of Pharmaceutical Sciences and Institute of Drug Discovery & Development, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, Henan, 450001, PR China.
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Zhou W, Ma L, Ding L, Guo Q, He Z, Yang J, Qiao H, Li L, Yang J, Yu S, Zhao L, Wang S, Liu HM, Suo Z, Zhao W. Potent 5-Cyano-6-phenyl-pyrimidin-Based Derivatives Targeting DCN1-UBE2M Interaction. J Med Chem 2019; 62:5382-5403. [PMID: 31157974 DOI: 10.1021/acs.jmedchem.9b00003] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Neddylation of the Cullin-RING E3 ligases (CRLs) regulates the homeostasis of approximately 20% of cellular proteins. Defective in cullin neddylation 1 (DCN1), as a co-E3 ligase, interacts with UBE2M to enhance the activation of CRLs, and this interaction is emerging as a therapeutic target for human diseases. Here, we present a series of pyrimidin-based small molecular inhibitors targeting DCN1-UBE2M interaction. After finding a novel inhibitor DC-1 with IC50 = 1.2 μM, we performed a series of chemical optimizations, which finally led to the discovery of a potent thiazole containing 5-cyano-6-phenylpyrimidin-based inhibitor DC-2 (IC50 = 15 nM). Next, using protein and cellular thermal shift assays, coimmunoprecipitation, molecular docking, and site-specific mutation experiments, we further proved that DC-2 specifically inhibited the interaction of UBE2M and DCN1 at molecule and cellular levels, resulting in the decrease of cullin3 neddylation and accumulation of its substrate, NRF2. Our findings indicate that DC-2 may serve as a novel lead compound for specific derivatives targeting DCN1-UBE2M interaction.
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Affiliation(s)
- Wenjuan Zhou
- State Key Laboratory of Esophageal Cancer Prevention and Treatment; Key Laboratory of Advanced Pharmaceutical Technology, Ministry of Education of China; School of Pharmaceutical Sciences , Zhengzhou University , 100 Kexue Avenue , Zhengzhou , Henan 450001 , China.,Department of Pathology , Oslo University Hospital; Faculty of Medicine, University of Oslo , Oslo 0379 , Norway
| | - Liying Ma
- State Key Laboratory of Esophageal Cancer Prevention and Treatment; Key Laboratory of Advanced Pharmaceutical Technology, Ministry of Education of China; School of Pharmaceutical Sciences , Zhengzhou University , 100 Kexue Avenue , Zhengzhou , Henan 450001 , China
| | - Lina Ding
- State Key Laboratory of Esophageal Cancer Prevention and Treatment; Key Laboratory of Advanced Pharmaceutical Technology, Ministry of Education of China; School of Pharmaceutical Sciences , Zhengzhou University , 100 Kexue Avenue , Zhengzhou , Henan 450001 , China
| | - Qian Guo
- State Key Laboratory of Esophageal Cancer Prevention and Treatment; Key Laboratory of Advanced Pharmaceutical Technology, Ministry of Education of China; School of Pharmaceutical Sciences , Zhengzhou University , 100 Kexue Avenue , Zhengzhou , Henan 450001 , China
| | - Zhangxu He
- State Key Laboratory of Esophageal Cancer Prevention and Treatment; Key Laboratory of Advanced Pharmaceutical Technology, Ministry of Education of China; School of Pharmaceutical Sciences , Zhengzhou University , 100 Kexue Avenue , Zhengzhou , Henan 450001 , China
| | - Jing Yang
- State Key Laboratory of Esophageal Cancer Prevention and Treatment; Key Laboratory of Advanced Pharmaceutical Technology, Ministry of Education of China; School of Pharmaceutical Sciences , Zhengzhou University , 100 Kexue Avenue , Zhengzhou , Henan 450001 , China
| | - Hui Qiao
- State Key Laboratory of Esophageal Cancer Prevention and Treatment; Key Laboratory of Advanced Pharmaceutical Technology, Ministry of Education of China; School of Pharmaceutical Sciences , Zhengzhou University , 100 Kexue Avenue , Zhengzhou , Henan 450001 , China
| | - Lingyu Li
- State Key Laboratory of Esophageal Cancer Prevention and Treatment; Key Laboratory of Advanced Pharmaceutical Technology, Ministry of Education of China; School of Pharmaceutical Sciences , Zhengzhou University , 100 Kexue Avenue , Zhengzhou , Henan 450001 , China
| | - Jie Yang
- State Key Laboratory of Esophageal Cancer Prevention and Treatment; Key Laboratory of Advanced Pharmaceutical Technology, Ministry of Education of China; School of Pharmaceutical Sciences , Zhengzhou University , 100 Kexue Avenue , Zhengzhou , Henan 450001 , China
| | - Shimin Yu
- State Key Laboratory of Esophageal Cancer Prevention and Treatment; Key Laboratory of Advanced Pharmaceutical Technology, Ministry of Education of China; School of Pharmaceutical Sciences , Zhengzhou University , 100 Kexue Avenue , Zhengzhou , Henan 450001 , China
| | - Lili Zhao
- State Key Laboratory of Esophageal Cancer Prevention and Treatment; Key Laboratory of Advanced Pharmaceutical Technology, Ministry of Education of China; School of Pharmaceutical Sciences , Zhengzhou University , 100 Kexue Avenue , Zhengzhou , Henan 450001 , China
| | - Shaomeng Wang
- State Key Laboratory of Esophageal Cancer Prevention and Treatment; Key Laboratory of Advanced Pharmaceutical Technology, Ministry of Education of China; School of Pharmaceutical Sciences , Zhengzhou University , 100 Kexue Avenue , Zhengzhou , Henan 450001 , China.,The Rogel Cancer Center and Departments of Internal Medicine, Pharmacology, Medicinal Chemistry and Pathology , University of Michigan Medical School , Ann Arbor , Michigan 48109 , United States
| | - Hong-Min Liu
- State Key Laboratory of Esophageal Cancer Prevention and Treatment; Key Laboratory of Advanced Pharmaceutical Technology, Ministry of Education of China; School of Pharmaceutical Sciences , Zhengzhou University , 100 Kexue Avenue , Zhengzhou , Henan 450001 , China
| | - Zhenhe Suo
- Department of Pathology , Oslo University Hospital; Faculty of Medicine, University of Oslo , Oslo 0379 , Norway
| | - Wen Zhao
- State Key Laboratory of Esophageal Cancer Prevention and Treatment; Key Laboratory of Advanced Pharmaceutical Technology, Ministry of Education of China; School of Pharmaceutical Sciences , Zhengzhou University , 100 Kexue Avenue , Zhengzhou , Henan 450001 , China
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Li Z, Cui Q, Wang X, Li B, Zhao D, Xia Q, Zhao P. Functions and substrates of NEDDylation during cell cycle in the silkworm, Bombyx mori. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2017; 90:101-112. [PMID: 28964913 DOI: 10.1016/j.ibmb.2017.09.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 09/22/2017] [Accepted: 09/26/2017] [Indexed: 06/07/2023]
Abstract
NEDDylation, a post-translational modification mediated by the conjugation of the ubiquitin-like protein Nedd8 to specific substrates, is an essential biological process that regulates cell cycle progression in eukaryotes. Here, we report the conservation of NEDDylation machinery and NEDDylated proteins in the silkworm, Bombyx mori. We have identified all the components necessary for reversible NEDDylation in the silkworm including Nedd8, E1, E2, E3, and deNEDDylation enzymes. By the approach of RNAi-mediated gene silencing, it was shown that knockdown of BmNedd8 and the conjugating enzymes decreased the global level of NEDDylation, while knockdown of deNEDDylation enzymes increased the prevalence of this modification in cultured silkworm cells. Moreover, the lack of the NEDDylation system caused cell cycle arrest at the G2/M phase and resulted in defects in chromosome congression and segregation. Using the wild-type and mutants of BmNedd8, we identified the specific substrates of BmNedd8, which are involved in the regulation for many cellular processes, including ribosome biogenesis, spliceosome structure, spindle formation, metabolism, and RNA biogenesis. This clearly demonstrates that the NEDDylation system is able to control multiple pathways in the silkworm. Altogether, the information on the functions and substrates of the NEDDylation system presented here could provide a basis for future investigations of protein NEDDylation and its regulatory mechanism on cell cycle progression in the silkworm.
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Affiliation(s)
- Zhiqing Li
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China; Chongqing Engineering and Technology Research Center for Novel Silk Materials, Chongqing, China
| | - Qixin Cui
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Xiaoyan Wang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Bingqian Li
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Dongchao Zhao
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Qingyou Xia
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China; Chongqing Engineering and Technology Research Center for Novel Silk Materials, Chongqing, China
| | - Ping Zhao
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China; Chongqing Engineering and Technology Research Center for Novel Silk Materials, Chongqing, China.
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5
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NEDDylation of PB2 Reduces Its Stability and Blocks the Replication of Influenza A Virus. Sci Rep 2017; 7:43691. [PMID: 28252002 PMCID: PMC5333077 DOI: 10.1038/srep43691] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 01/30/2017] [Indexed: 02/07/2023] Open
Abstract
Post-translational modifications of viral proteins play important roles in regulating viral replication. Here we demonstrated that the PB2 of influenza A virus (IAV) can be modified by NEDD8. We revealed that E3 ligase HDM2 can promote PB2 NEDDylation. Overexpression of either NEDD8 or HDM2 can inhibit IAV replication, while knockdown of HDM2 has the opposite effect. Then we identified residue K699 in PB2 as the major NEDDylation site. We found that NEDDylation deficient PB2 mutant (PB2 K699R) has a longer half-life than wild-type PB2, indicating that NEDDylation of PB2 reduces its stability. We generated an IAV mutant in which PB2 was mutated to PB2 K699R (WSN-PB2 K699R) and examined the replication of WSN and WSN-PB2 K699R viruses in both MDCK and A549 cells and found that the replication of WSN-PB2 K699R was more efficient than wild-type WSN. In addition, we observed that overexpression of NEDD8 significantly inhibited the replication of WSN, but not WSN-PB2 K699R. The infection assay in mice showed that WSN-PB2 K699R exhibited enhanced virulence in mice compared to WSN, suggesting that NEDDylation of PB2 reduced IAV replication in vivo. In conclusion, we demonstrated that NEDDylation of PB2 by HDM2 negatively regulates IAV infection.
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Ehrentraut SF, Curtis VF, Wang RX, Saeedi BJ, Ehrentraut H, Onyiah JC, Kelly CJ, Campbell EL, Glover LE, Kominsky DJ, Colgan SP. Perturbation of neddylation-dependent NF-κB responses in the intestinal epithelium drives apoptosis and inhibits resolution of mucosal inflammation. Mol Biol Cell 2016; 27:mbc.E16-05-0273. [PMID: 27682585 PMCID: PMC5170552 DOI: 10.1091/mbc.e16-05-0273] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Revised: 09/19/2016] [Accepted: 09/20/2016] [Indexed: 01/30/2023] Open
Abstract
Recent work has revealed a central role for neddylation (the conjugation of a Nedd8-moiety to Cullin proteins) in the fine tuning of the NF-κB response (via Cullin-1). In the present study, we investigated the contribution of Cullin-1 neddylation and NF-κB signaling to mucosal inflammatory responses in vitro and in vivo. Initial in vitro studies using cultured intestinal epithelial cells revealed that the neddylation inhibitor MLN4924 prominently induces the deneddylation of Cullin-1. Parallel western blot, luciferase reporter and gene target assays identified MLN4924 as a potent inhibitor of intestinal epithelial NF-κB. Subsequent studies revealed that MLN4924 potently induces epithelial apoptosis but only in the presence of additional inflammatory stimuli. In vivo administration of MLN4924 (3 mg/kg/d) in a TNBS-induce colitis model significantly accentuated disease severity. Indeed, MLN4924 resulted in worsened clinical scores and increased mortality early in the inflammatory response. Histologic analysis of the colon revealed that neddylation inhibition results in increased tissue damage and significantly increased mucosal apoptosis as determined by TUNEL and cleaved caspase-3 staining, particularly prominent within the epithelium. Extensions of these studies revealed that ongoing inflammation is associated with significant loss of deneddylase-1 (SENP8) expresssion. These studies reveal that intact Cullin-1 neddylation is central to resolution of acute inflammation.
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Affiliation(s)
- Stefan F Ehrentraut
- Mucosal Inflammation Program, Department of Medicine and Immunology, University of Colorado School of Medicine, Aurora, CO 80045 Department of Anesthesiology, University Hospital Bonn, Germany
| | - Valerie F Curtis
- Mucosal Inflammation Program, Department of Medicine and Immunology, University of Colorado School of Medicine, Aurora, CO 80045
| | - Ruth X Wang
- Mucosal Inflammation Program, Department of Medicine and Immunology, University of Colorado School of Medicine, Aurora, CO 80045
| | - Bejan J Saeedi
- Mucosal Inflammation Program, Department of Medicine and Immunology, University of Colorado School of Medicine, Aurora, CO 80045
| | - Heidi Ehrentraut
- Mucosal Inflammation Program, Department of Medicine and Immunology, University of Colorado School of Medicine, Aurora, CO 80045 Department of Anesthesiology, University Hospital Bonn, Germany
| | - Joseph C Onyiah
- Mucosal Inflammation Program, Department of Medicine and Immunology, University of Colorado School of Medicine, Aurora, CO 80045 Eastern Colorado Veterans Affairs Hospital, Denver, CO
| | - Caleb J Kelly
- Mucosal Inflammation Program, Department of Medicine and Immunology, University of Colorado School of Medicine, Aurora, CO 80045
| | - Eric L Campbell
- Mucosal Inflammation Program, Department of Medicine and Immunology, University of Colorado School of Medicine, Aurora, CO 80045
| | - Louise E Glover
- Mucosal Inflammation Program, Department of Medicine and Immunology, University of Colorado School of Medicine, Aurora, CO 80045
| | - Douglas J Kominsky
- Mucosal Inflammation Program, Department of Medicine and Immunology, University of Colorado School of Medicine, Aurora, CO 80045 Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59717
| | - Sean P Colgan
- Mucosal Inflammation Program, Department of Medicine and Immunology, University of Colorado School of Medicine, Aurora, CO 80045 Eastern Colorado Veterans Affairs Hospital, Denver, CO
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Labusch C, Effendi Y, Fulda M, Scherer GFE. Transcription of TIR1-Controlled Genes Can be Regulated within 10 Min by an Auxin-Induced Process. Can TIR1 be the Receptor? FRONTIERS IN PLANT SCIENCE 2016; 7:995. [PMID: 27462327 PMCID: PMC4939301 DOI: 10.3389/fpls.2016.00995] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 06/22/2016] [Indexed: 05/30/2023]
Abstract
ABP1 and TIR1/AFBs are known as auxin receptors. ABP1 is linked to auxin responses several of which are faster than 10 min. TIR1 regulates auxin-induced transcription of early auxin genes also within minutes. We use transcription of such TIR1-dependent genes as indicator of TIR1 activity to show the rapid regulation of TIR1 by exogenous auxin. To this end, we used quantification of transcription of a set of fifteen early auxin-induced reporter genes at t = 10 and t = 30 min to measure this as a TIR1-dependent auxin response. We conducted this study in 22 mutants of auxin transporters (pin5, abcb1, abcb19, and aux1/lax3), protein kinases and phosphatases (ibr5, npr1, cpk3, CPK3-OX, d6pk1, d6pkl1-1, d6pkl3-2, d6pkl1-1/d6pkl2-2, and d6pkl1-1/d6pkl3-2), of fatty acid metabolism (fad2-1, fad6-1, ssi2, lacs4, lacs9, and lacs4/lacs9) and receptors (tir1, tir1/afb2, and tir1/afb3) and compared them to the wild type. After 10 min auxin application, in 18 out of 22 mutants mis-regulated expression of at least one reporter was found, and in 15 mutants transcription of two-to-three out of five selected auxin reporter genes was mis-regulated. After 30 min of auxin application to mutant plants, mis-regulation of reporter genes ranged from one to 13 out of 15 tested reporter genes. Those genes chosen as mutants were themselves not regulated in their expression by auxin for at least 1 h, excluding an influence of TIR1/AFBs on their transcription. The expression of TIR1/AFB genes was also not modulated by auxin for up to 3 h. Together, this excludes a feedback or feedforward of these mutant genes/proteins on TIR1/AFBs output of transcription in this auxin-induced response. However, an auxin-induced response needed an as yet unknown auxin receptor. We suggest that the auxin receptor necessary for the fast auxin-induced transcription modulation could be, instead, ABP1. The alternative hypothesis would be that auxin-induced expression of a protein, initiated by TIR1/AFBs receptors, could initiate these responses and that this unknown protein regulated TIR1/AFB activities within 10 min.
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Affiliation(s)
- Corinna Labusch
- Abteilung Molekulare Ertragsphysiologie, Institut für Gartenbauliche Produktionssysteme, Leibniz Universität HannoverHannover, Germany
| | - Yunus Effendi
- Abteilung Molekulare Ertragsphysiologie, Institut für Gartenbauliche Produktionssysteme, Leibniz Universität HannoverHannover, Germany
- Department of Biology, University of Al Azhar IndonesiaJakarta, Indonesia
| | - Martin Fulda
- Abteilung Biochemie der Pflanzen, Albrecht-von-Haller-Institut der Pflanzenwissenschaften, Universität GöttingenGöttingen, Germany
| | - Günther F. E. Scherer
- Abteilung Molekulare Ertragsphysiologie, Institut für Gartenbauliche Produktionssysteme, Leibniz Universität HannoverHannover, Germany
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Fu W, Sun J, Huang G, Liu JC, Kaufman A, Ryan RJH, Ramanathan SY, Venkatesh T, Singh B. Squamous Cell Carcinoma-related Oncogene (SCCRO) Family Members Regulate Cell Growth and Proliferation through Their Cooperative and Antagonistic Effects on Cullin Neddylation. J Biol Chem 2016; 291:6200-17. [PMID: 26792857 DOI: 10.1074/jbc.m115.692756] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Indexed: 11/06/2022] Open
Abstract
SCCRO (squamous cell carcinoma-related oncogene; also known as DCUN1D1) is a highly conserved gene that functions as an E3 in neddylation. Although inactivation of SCCRO in yeast results in lethality, SCCRO(-/-) mice are viable. The exclusive presence of highly conserved paralogues in higher organisms led us to assess whether compensation by SCCRO paralogues rescues lethality in SCCRO(-/-) mice. Using murine and Drosophila models, we assessed the in vivo activities of SCCRO and its paralogues in cullin neddylation. We found that SCCRO family members have overlapping and antagonistic activity that regulates neddylation and cell proliferation activities in vivo. In flies, both dSCCRO and dSCCRO3 promote neddylation and cell proliferation, whereas dSCCRO4 negatively regulates these processes. Analysis of somatic clones showed that the effects that these paralogues have on proliferation serve to promote cell competition, leading to apoptosis in clones with a net decrease in neddylation activity. We found that dSCCRO and, to a lesser extent, dSCCRO3 rescue the neddylation and proliferation defects promoted by expression of SCCRO4. dSCCRO and dSCCRO3 functioned cooperatively, with their coexpression resulting in an increase in both the neddylated cullin fraction and proliferation activity. In contrast, human SCCRO and SCCRO4 promote, and human SCCRO3 inhibits, neddylation and proliferation when expressed in flies. Our findings provide the first insights into the mechanisms through which SCCRO family members cooperatively regulate neddylation and cell proliferation.
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Affiliation(s)
- Weimin Fu
- From the Department of Surgery, Laboratory of Epithelial Cancer Biology, Memorial Sloan Kettering Cancer Center, New York, New York 10065 and
| | - Joanne Sun
- From the Department of Surgery, Laboratory of Epithelial Cancer Biology, Memorial Sloan Kettering Cancer Center, New York, New York 10065 and
| | - Guochang Huang
- From the Department of Surgery, Laboratory of Epithelial Cancer Biology, Memorial Sloan Kettering Cancer Center, New York, New York 10065 and
| | - Jeffrey C Liu
- From the Department of Surgery, Laboratory of Epithelial Cancer Biology, Memorial Sloan Kettering Cancer Center, New York, New York 10065 and
| | - Andrew Kaufman
- From the Department of Surgery, Laboratory of Epithelial Cancer Biology, Memorial Sloan Kettering Cancer Center, New York, New York 10065 and
| | - Russell J H Ryan
- From the Department of Surgery, Laboratory of Epithelial Cancer Biology, Memorial Sloan Kettering Cancer Center, New York, New York 10065 and
| | - Suresh Y Ramanathan
- From the Department of Surgery, Laboratory of Epithelial Cancer Biology, Memorial Sloan Kettering Cancer Center, New York, New York 10065 and
| | - Tadmiri Venkatesh
- Department of Biology, The City College of New York, New York, New York 10031
| | - Bhuvanesh Singh
- From the Department of Surgery, Laboratory of Epithelial Cancer Biology, Memorial Sloan Kettering Cancer Center, New York, New York 10065 and
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Abstract
In this review, I summarize some of the recent insight into pharmacological targeting of hypoxia in disease models. Studies from cultured cell systems, animal models, and translation to human patients have revealed that posttranslational modifications of individual proteins within NF-κB and hypoxia-inducible factor pathways serve as ideal targets for analysis in disease models. Studies defining differences and similarities between these responses have taught us a number of important lessons about the complexity of the inflammatory response. A clearer definition of these pathways has provided new insight into disease pathogenesis and, importantly, the potential for new therapeutic targets.
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10
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Wu S, Yu L. Targeting cullin-RING ligases for cancer treatment: rationales, advances and therapeutic implications. Cytotechnology 2015; 68:1-8. [PMID: 25899169 DOI: 10.1007/s10616-015-9870-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Accepted: 03/26/2015] [Indexed: 02/02/2023] Open
Abstract
New therapeutic intervention strategies for the treatment of human malignancies are always desired. Approval of bortezomib as a front-line treatment for multiple myeloma highlighted the significance of ubiquitin-proteasome system (UPS) as a promising therapeutic target. However, due to the broad impact of proteasome inhibition, deleterious side effects have been reported with bortezomib treatment. Cullin RING ligases (CRLs)-mediated ubiquitin conjugation process is responsible for the ubiquitin conjugation of 20 % cellular proteins that are designated for degradation through the UPS, most of them are critical proteins involved in cell cycle progression, signaling transduction and apoptosis. Studies have depicted the upstream NEDDylation pathway that controls the CRL activity by regulating the conjugation of an ubiquitin-like-protein NEDD8 to the cullin protein in the complex. A specific pharmaceutical inhibitor of NEDD8 activating enzyme (NAE; E1) MLN4924 was recently developed and has been promoted to Phase I clinical trials for the treatment of several human malignancies. This article summarizes the most recent understanding about the process of NEDD8 conjugation, its relevance for cancer therapy and molecular mechanisms responsible for the potent anti-tumor activity of MLN4924.
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Affiliation(s)
- Shuju Wu
- School of Life Science and Technology, Harbin Normal University, Harbin, 150025, People's Republic of China.
| | - Lijie Yu
- School of Life Science and Technology, Harbin Normal University, Harbin, 150025, People's Republic of China
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11
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Neutrophils and inflammatory resolution in the mucosa. Semin Immunol 2015; 27:177-83. [PMID: 25818531 DOI: 10.1016/j.smim.2015.03.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 03/10/2015] [Accepted: 03/11/2015] [Indexed: 12/13/2022]
Abstract
Inflammatory diseases in mucosal organs as diverse as the lung, liver and intestine inevitably require the intimate interactions between neutrophils and epithelia. The physiologic consequences of such interactions often determine endpoint organ function, and for this reason, much recent interest has developed in identifying mechanisms and novel targets to promote the resolution of mucosal inflammation. Physiologically-relevant in vitro and in vivo model systems have aided in discovery of novel pathways to define basic inflammatory mechanisms and approaches to defining the concepts of inflammatory resolution. Here, we will review the recent literature regarding the contribution of neutrophils to inflammatory resolution, with an emphasis on the role of the tissue microenvironment, endogenous pathways for promoting resolution and the molecular determinants of neutrophil-epithelial cell interactions during ongoing inflammation. These recent studies highlight the dynamic nature of pro-resolving pathways and lend insight into the complexity of treating mucosal inflammation.
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12
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Hosp J, Ribarits A, Retzer K, Jin Y, Tashpulatov A, Resch T, Friedmann C, Ankele E, Voronin V, Palme K, Heberle-Bors E, Touraev A. A tobacco homolog of DCN1 is involved in pollen development and embryogenesis. PLANT CELL REPORTS 2014; 33:1187-202. [PMID: 24748527 DOI: 10.1007/s00299-014-1609-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Revised: 03/13/2014] [Accepted: 03/22/2014] [Indexed: 05/08/2023]
Abstract
KEY MESSAGE We show that DCN1 binds ubiquitin and RUB/NEDD8, associates with cullin, and is functionally conserved. DCN1 activity is required for pollen development transitions and embryogenesis, and for pollen tube growth. Plant proteomes show remarkable plasticity in reaction to environmental challenges and during developmental transitions. Some of this adaptability comes from ubiquitin-mediated protein degradation regulated by cullin-RING E3 ubiquitin ligases (CRLs). CRLs are activated through modification of the cullin subunit with the ubiquitin-like protein RUB/NEDD8 by an E3 ligase called defective in cullin neddylation 1 (DCN1). Here we show that tobacco DCN1 binds ubiquitin and RUB/NEDD8 and associates with cullin. When knocked down by RNAi, tobacco pollen formation was affected and zygotic embryogenesis was blocked around the globular stage. Additionally, we found that RNAi of DCN1 inhibited the stress-triggered reprogramming of cultured microspores from their intrinsic gametophytic mode of development to an embryogenic state. This stress-induced developmental switch is a known feature in many important crops and leads ultimately to the formation of haploid embryos and plants. Compensating the RNAi effect by re-transformation with a promoter-silencing construct restored pollen development and zygotic embryogenesis, as well as the ability for stress-induced formation of embryogenic microspores. Overexpression of DCN1 accelerated pollen tube growth and increased the potential for microspore reprogramming. These results demonstrate that the biochemical function of DCN1 is conserved in plants and that its activity is involved in transitions during pollen development and embryogenesis, and for pollen tube growth.
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Affiliation(s)
- Julia Hosp
- Max F. Perutz Laboratories, Vienna University, Dr. Bohrgasse 9, 1030, Vienna, Austria
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13
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Mir R, León J. Pathogen and circadian controlled 1 (PCC1) protein is anchored to the plasma membrane and interacts with subunit 5 of COP9 signalosome in Arabidopsis. PLoS One 2014; 9:e87216. [PMID: 24475254 PMCID: PMC3903633 DOI: 10.1371/journal.pone.0087216] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Accepted: 12/25/2013] [Indexed: 12/03/2022] Open
Abstract
The Pathogen and Circadian Controlled 1 (PCC1) gene, previously identified and further characterized as involved in defense to pathogens and stress-induced flowering, codes for an 81-amino acid protein with a cysteine-rich C-terminal domain. This domain is essential for homodimerization and anchoring to the plasma membrane. Transgenic plants with the ß-glucuronidase (GUS) reporter gene under the control of 1.1 kb promoter sequence of PCC1 gene display a dual pattern of expression. At early post-germination, PCC1 is expressed only in the root vasculature and in the stomata guard cells of cotyledons. During the transition from vegetative to reproductive development, PCC1 is strongly expressed in the vascular tissue of petioles and basal part of the leaf, and it further spreads to the whole limb in fully expanded leaves. This developmental pattern of expression together with the late flowering phenotype of long-day grown RNA interference (iPCC1) plants with reduced PCC1 expression pointed to a regulatory role of PCC1 in the photoperiod-dependent flowering pathway. iPCC1 plants are defective in light perception and signaling but are not impaired in the function of the core CO-FT module of the photoperiod-dependent pathway. The regulatory effect exerted by PCC1 on the transition to flowering as well as on other reported phenotypes might be explained by a mechanism involving the interaction with the subunit 5 of the COP9 signalosome (CSN).
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Affiliation(s)
- Ricardo Mir
- Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia, Valencia, Spain
| | - José León
- Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia, Valencia, Spain
- * E-mail:
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14
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Andérica-Romero AC, González-Herrera IG, Santamaría A, Pedraza-Chaverri J. Cullin 3 as a novel target in diverse pathologies. Redox Biol 2013; 1:366-72. [PMID: 24024173 PMCID: PMC3757711 DOI: 10.1016/j.redox.2013.07.003] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Revised: 06/28/2013] [Accepted: 07/09/2013] [Indexed: 12/12/2022] Open
Abstract
Recent evidence suggests that the malfunctioning disposal system of cell protein called ubiquitin–proteasome system (UPS) plays an important role in the development of disorders, including cancer and neurodegenerative diseases. Accumulating evidence suggests that the abnormal regulation of the E3 ubiquitin ligases, essential components of the UPS, contributes to uncontrolled proliferation, genomic instability and cancer, since these ligases and their substrates are involved in the regulation of cell cycle progression, gene transcription, signal transduction, DNA replication and others. Through selective degradation of specific substrates, E3 ligases regulate different biological processes. Cullins are a family of proteins that confer substrate specificity to multimeric complex of E3 ligases acting as scaffold proteins. So far, seven members of the cullin family of proteins have been identified. Interestingly, the data generated by several groups indicate that cullin 3 (Cul3) has begun to emerge as a protein involved in the etiopathology of multiple diseases. In this paper we examine the latest advances in basic research on the biology of Cul3 and how it could help to direct drug discovery efforts on this target. The most important system for protein degradation is the ubiquitin–proteasome system. The specific substrate for ubiquitination is highly specific and this activity can be provided by the E3 ubiquitin ligases. The E3 ubiquitin ligases based on cullins are the type of ubiquitin ligases more studied. The cullin 3 complex has emerged as a target due to its interaction with a wide range of BTB-proteins. Cullin 3 could be a molecule with a high therapeutic potential.
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Affiliation(s)
- Ana Cristina Andérica-Romero
- Facultad de Química, Departamento de Biología, Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria, 04510 México D.F., México
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15
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Ferrández-Ayela A, Alonso-Peral MM, Sánchez-García AB, Micol-Ponce R, Pérez-Pérez JM, Micol JL, Ponce MR. Arabidopsis TRANSCURVATA1 encodes NUP58, a component of the nucleopore central channel. PLoS One 2013; 8:e67661. [PMID: 23840761 PMCID: PMC3695937 DOI: 10.1371/journal.pone.0067661] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Accepted: 05/20/2013] [Indexed: 01/20/2023] Open
Abstract
The selective trafficking of proteins and RNAs through the nuclear envelope regulates nuclear-cytoplasmic segregation of macromolecules and is mediated by nucleopore complexes (NPCs), which consist of about 400 nucleoporins (Nups) of about 30 types. Extensive studies of nucleoporin function in yeast and vertebrates showed that Nups function in nucleocytoplasmic trafficking and other processes. However, limited studies of plant Nups have identified only a few mutations, which cause pleiotropic phenotypes including reduced growth and early flowering. Here, we describe loss-of-function alleles of Arabidopsis TRANSCURVATA1 (TCU1); these mutations cause increased hypocotyl and petiole length, reticulate and asymmetrically epinastic leaf laminae of reduced size, and early flowering. TCU1 is transcribed in all of the organs and tissues examined, and encodes the putative ortholog of yeast and vertebrate Nup58, a nucleoporin of the Nup62 subcomplex. Nup58 forms the central channel of the NPC and acts directly in translocation of proteins through the nuclear envelope in yeast and vertebrates. Yeast two-hybrid (Y2H) assays identified physical interactions between TCU1/NUP58 and 34 proteins, including nucleoporins, SCF (Skp1/Cul1/F-box) ubiquitin ligase complex components and other nucleoplasm proteins. Genetic interactions were also found between TCU1 and genes encoding nucleoporins, soluble nuclear transport receptors and components of the ubiquitin-proteasome and auxin signaling pathways. These genetic and physical interactions indicate that TCU1/NUP58 is a member of the Nup62 subcomplex of the Arabidopsis NPC. Our findings also suggest regulatory roles for TCU1/NUP58 beyond its function in nucleocytoplasmic trafficking, a hypothesis that is supported by the Y2H and genetic interactions that we observed.
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Affiliation(s)
| | | | | | - Rosa Micol-Ponce
- Instituto de Bioingeniería, Universidad Miguel Hernández, Campus de Elche, Elche, Spain
| | | | - José Luis Micol
- Instituto de Bioingeniería, Universidad Miguel Hernández, Campus de Elche, Elche, Spain
| | - María Rosa Ponce
- Instituto de Bioingeniería, Universidad Miguel Hernández, Campus de Elche, Elche, Spain
- * E-mail:
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16
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Colgan SP, Ehrentraut SF, Glover LE, Kominsky DJ, Campbell EL. Contributions of neutrophils to resolution of mucosal inflammation. Immunol Res 2013; 55:75-82. [PMID: 22968707 DOI: 10.1007/s12026-012-8350-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Neutrophil (PMN) recruitment from the blood stream into surrounding tissues involves a regulated series of events central to acute responses in host defense. Accumulation of PMN within mucosal tissues has historically been considered pathognomonic features of both acute and chronic inflammatory conditions. Historically, PMNs have been deemed necessary but detrimental when recruited, given the potential for tissue damage that results from a variety of mechanisms. Recent work, however, has altered our preconceived notions of PMN contributions to inflammatory processes. In particular, significant evidence implicates a central role for the PMN in triggering inflammatory resolution. Such mechanisms involve both metabolic and biochemical crosstalk pathways during the intimate interactions of PMN with other cell types at inflammatory sites. Here, we highlight several recent examples of how PMN coordinate the resolution of ongoing inflammation, with a particular focus on the gastrointestinal mucosa.
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Affiliation(s)
- Sean P Colgan
- Department of Medicine and the Mucosal Inflammation Program, University of Colorado School of Medicine, Aurora, CO 80045, USA.
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17
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Colgan SP, Fennimore B, Ehrentraut SF. Adenosine and gastrointestinal inflammation. J Mol Med (Berl) 2013; 91:157-64. [PMID: 23296303 DOI: 10.1007/s00109-012-0990-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Revised: 12/04/2012] [Accepted: 12/18/2012] [Indexed: 12/23/2022]
Abstract
Nucleosides such as adenosine (Ado) influence nearly every aspect of physiology and pathophysiology. Extracellular nucleotides liberated at local sites of inflammation are metabolized through regulated phosphohydrolysis by a series of ecto-nucleotidases including ectonucleoside triphosphate diphosphohydrolase-1 (CD39) and ecto-5'-nucleotidase (CD73), found on the surface of a variety of cell types. Once generated, Ado is made available to bind and activate one of four G protein-coupled Ado receptors. Recent in vitro and in vivo studies implicate Ado in a broad array of tissue-protective mechanisms that provide new insight into adenosine actions. Studies in cultured cells and murine tissues have indicated that Ado receptors couple to novel posttranslational protein modifications, including Cullin deneddylation, as a new anti-inflammatory mechanism. Studies in Ado receptor-null mice have been revealing and indicate a particularly important role for the Ado A2B receptor in animal models of intestinal inflammation. Here, we review contributions of Ado to cell and tissue stress responses, with a particular emphasis on the gastrointestinal mucosa.
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Affiliation(s)
- Sean P Colgan
- Department of Medicine and Mucosal Inflammation Program, University of Colorado School of Medicine, 12700 East 19th Ave., MS B-146, Aurora, CO 80045, USA.
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18
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Ehrentraut SF, Kominsky DJ, Glover LE, Campbell EL, Kelly CJ, Bowers BE, Bayless AJ, Colgan SP. Central role for endothelial human deneddylase-1/SENP8 in fine-tuning the vascular inflammatory response. THE JOURNAL OF IMMUNOLOGY 2012; 190:392-400. [PMID: 23209320 DOI: 10.4049/jimmunol.1202041] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
A deeper understanding of the mechanisms that control responses to inflammation is critical to the development of effective therapies. We sought to define the most proximal regulators of the Cullin (Cul)-RING ligases, which play a central role in the stabilization of NF-κB and hypoxia-inducible factor (HIF). In these studies, we identify the human deneddylase-1 (SENP8) as a key regulator of Cul neddylation response in vitro and in vivo. Using human microvascular endothelial cells (HMECs), we examined inflammatory responses to LPS or TNF-α by assessing Cul neddylation status, NF-κB and HIF-1α stabilization, and inflammatory cytokine secretion. HMECs with an intact neddylation pathway showed a time-dependent induction of Cul-1 neddylation, nuclear translocation of NF-κB, stabilization of HIF-1α, and increased NF-κB/HIF-α promoter activity in response to LPS. HMECs lacking SENP8 were unable to neddylate Cul-1 and subsequently were unable to activate NF-κB or HIF-1α. Pharmacological targeting of neddylation (MLN4924) significantly abrogated NF-κB responses, induced HIF-1α promoter activity, and reduced secretion of TNF-α-elicited proinflammatory cytokines. MLN4924 stabilized HIF and abrogated proinflammatory responses while maintaining anti-inflammatory IL-10 responses in vivo following LPS administration. These studies identify SENP8 as a proximal regulator of Cul neddylation and provide an important role for SENP8 in fine-tuning the inflammatory response. Moreover, our findings provide feasibility for therapeutic targeting of the Culs during inflammation.
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Affiliation(s)
- Stefan F Ehrentraut
- Mucosal Inflammation Program, Department of Medicine and Immunology, University of Colorado School of Medicine, Aurora, CO 80045, USA
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19
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Ehrentraut SF, Colgan SP. Implications of protein post-translational modifications in IBD. Inflamm Bowel Dis 2012; 18:1378-88. [PMID: 22223542 PMCID: PMC3378042 DOI: 10.1002/ibd.22859] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Accepted: 11/22/2011] [Indexed: 12/19/2022]
Abstract
In recent years our understanding of the pathogenesis of inflammatory bowel disease (IBD) has greatly increased. Hallmarks of IBD include loss of intestinal barrier function, increased cytokine production, and failed resolution of tissue damage. Lasting treatments are still lacking and, therefore, a better understanding of the underlying molecular mechanisms is necessary to design novel therapeutic approaches. Apart from transcriptional and posttranscriptional regulation of relevant genes, mammals have evolved a complex and efficient series of mechanisms to rapidly modify newly made proteins for the purposes of signaling and adaptation. These posttranslational protein modifications include, among others, phosphorylation, hydroxylation, neddylation, and cytokine cleavage by the inflammasome. This review focuses on our current understanding of posttranslational protein modifications with a particular focus on their relevance to IBD pathogenesis.
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Affiliation(s)
- Stefan F Ehrentraut
- Department of Medicine and Mucosal Inflammation Program, University of Colorado School of Medicine, Aurora, Colorado 80045, USA.
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20
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Gastaldello S, Callegari S, Coppotelli G, Hildebrand S, Song M, Masucci MG. Herpes virus deneddylases interrupt the cullin-RING ligase neddylation cycle by inhibiting the binding of CAND1. J Mol Cell Biol 2012; 4:242-51. [DOI: 10.1093/jmcb/mjs012] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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21
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In silico analysis of ubiquitin/ubiquitin-like modifiers and their conjugating enzymes in Entamoeba species. Parasitol Res 2012; 111:37-51. [DOI: 10.1007/s00436-011-2799-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Accepted: 12/19/2011] [Indexed: 10/14/2022]
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22
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Colgan SP, Eltzschig HK. Adenosine and hypoxia-inducible factor signaling in intestinal injury and recovery. Annu Rev Physiol 2011; 74:153-75. [PMID: 21942704 DOI: 10.1146/annurev-physiol-020911-153230] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The gastrointestinal mucosa has proven to be an interesting tissue in which to investigate disease-related metabolism. In this review, we outline some of the evidence that implicates hypoxia-mediated adenosine signaling as an important signature within both healthy and diseased mucosa. Studies derived from cultured cell systems, animal models, and human patients have revealed that hypoxia is a significant component of the inflammatory microenvironment. These studies have revealed a prominent role for hypoxia-induced factor (HIF) and hypoxia signaling at several steps along the adenine nucleotide metabolism and adenosine receptor signaling pathways. Likewise, studies to date in animal models of intestinal inflammation have demonstrated an almost uniformly beneficial influence of HIF stabilization on disease outcomes. Ongoing studies to define potential similarities with and differences between innate and adaptive immune responses will continue to teach us important lessons about the complexity of the gastrointestinal tract. Such information has provided new insights into disease pathogenesis and, importantly, will provide insights into new therapeutic targets.
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Affiliation(s)
- Sean P Colgan
- Departments of Medicine and Anesthesiology and the Mucosal Inflammation Program, University of Colorado School of Medicine, Aurora, Colorado 80045, USA.
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23
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MacManus CF, Campbell EL, Keely S, Burgess A, Kominsky DJ, Colgan SP. Anti-inflammatory actions of adrenomedullin through fine tuning of HIF stabilization. FASEB J 2011; 25:1856-64. [PMID: 21350119 DOI: 10.1096/fj.10-170316] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In intact mucosal tissues, epithelial cells are anatomically positioned in proximity to a number of subepithelial cell types, including endothelia. A number of recent studies have suggested that imbalances between energy supply and demand can result in "inflammatory hypoxia." Given these associations, we hypothesized that endothelial-derived, hypoxia-inducible mediators might influence epithelial function. Guided by cDNA microarray analysis of human microvascular endothelial cells (HMEC-1 line) subjected to hypoxia (pO(2) 20 torr, 8 h), we identified adrenomedullin (ADM) as a prominent hypoxia-inducible factor (HIF) that acts on epithelial cells through cell surface receptors. We assessed the functional ability for exogenous ADM to signal in human intestinal Caco2 cells in vitro by demonstrating a dose-dependent induction of Erk1/2phosphorylation. Further analysis revealed that ADM deneddylates cullin-2 (Cul2), whose action has been demonstrated to control the activity of HIF. Caco2 cells stably expressing a hypoxic response element (HRE)-driven luciferase promoter confirmed that ADM activates the HIF signaling pathway. Extensions of these studies revealed an increase in canonical HIF-1-dependent genes following stimulation with ADM. To define physiological relevance, we investigated the effect of ADM in a DSS model of murine colitis. Administration of ADM resulted in reduced inflammatory indices and less severe histological inflammation compared to vehicle controls. Analysis of tissue and serum cytokines showed a marked and significant inhibition of colitis-associated TNF-α, IL-1β, and KC. Analysis of circulating ADM demonstrated an increase in serum ADM in murine models of colitis. Taken together, these results identify ADM as an endogenously generated vascular mediator that functions as a mucosal protective factor through fine tuning of HIF activity.
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Affiliation(s)
- Christopher F MacManus
- Department of Medicine, University of Colorado Health Sciences Center, Aurora, Colorado, USA
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24
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Huang G, Kaufman AJ, Ramanathan Y, Singh B. SCCRO (DCUN1D1) promotes nuclear translocation and assembly of the neddylation E3 complex. J Biol Chem 2011; 286:10297-304. [PMID: 21247897 DOI: 10.1074/jbc.m110.203729] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
SCCRO/DCUN1D1/DCN1 (squamous cell carcinoma-related oncogene/defective in cullin neddylation 1 domain containing 1/defective in cullin neddylation) serves as an accessory E3 in neddylation by binding to cullin and Ubc12 to allow efficient transfer of Nedd8. In this work we show that SCCRO has broader, pleiotropic effects that are essential for cullin neddylation in vivo. Reduced primary nuclear localization of Cul1 accompanying decreased neddylation and proliferation in SCCRO(-/-) mouse embryonic fibroblasts led us to investigate whether compartmentalization plays a regulatory role. Decreased nuclear localization, neddylation, and defective proliferation in SCCRO(-/-) mouse embryonic fibroblasts were rescued by transgenic expression of SCCRO. Expression of reciprocal SCCRO and Cul1-binding mutants confirmed the requirement for SCCRO in nuclear translocation and neddylation of cullins in vivo. Nuclear translocation of Cul1 by tagging with a nuclear localization sequence allowed neddylation independent of SCCRO, but at a lower level. We found that in the nucleus, SCCRO enhances recruitment of Ubc12 to Cul1 to promote neddylation. These findings suggest that SCCRO has an essential role in neddylation in vivo involving nuclear localization of neddylation components and recruitment and proper positioning of Ubc12.
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Affiliation(s)
- Guochang Huang
- Department of Surgery, Laboratory of Epithelial Cancer Biology, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA
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25
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Wang M, Medeiros BC, Erba HP, DeAngelo DJ, Giles FJ, Swords RT. Targeting protein neddylation: a novel therapeutic strategy for the treatment of cancer. Expert Opin Ther Targets 2011; 15:253-64. [PMID: 21219242 DOI: 10.1517/14728222.2011.550877] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
INTRODUCTION The NEDD8 (neural precursor cell-expressed developmentally downregulated 8) conjugation pathway regulates the post-translational modification of oncogenic proteins. This pathway has important potential for cancer therapeutics. Several proteins vital in cancer biology are regulated by protein neddylation. These observations led to the development of a small molecule inhibitor that disrupts protein neddylation and leads to cancer cell death and important activity in early phase clinical trials. AREAS COVERED This review provides an extensive coverage of cellular protein homeostasis with particular emphasis on the NEDD8 conjugation pathway. Insights into a new investigational drug that specifically disrupts the NEDD8 pathway are discussed. The clinical data for this agent are also updated. EXPERT OPINION Neddylation controls key cellular pathways found to be dysregulated in many cancers. Protein neddylation is a relatively under-explored pathway for pharmacologic inhibition in cancer. Selective disruption of this pathway has demonstrated clinical activity in patients with myeloid neoplasms and is worth exploring further in combination with other anti-leukemia agents.
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Affiliation(s)
- Meng Wang
- Cambridge University, Medicine, Cambridge, UK
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26
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Solution structure and activation mechanism of ubiquitin-like small archaeal modifier proteins. J Mol Biol 2010; 405:1040-55. [PMID: 21112336 DOI: 10.1016/j.jmb.2010.11.040] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2010] [Revised: 11/18/2010] [Accepted: 11/19/2010] [Indexed: 11/23/2022]
Abstract
In archaea, two ubiquitin-like small archaeal modifier protein (SAMPs) were recently shown to be conjugated to proteins in vivo. SAMPs display homology to bacterial MoaD sulfur transfer proteins and eukaryotic ubiquitin-like proteins, and they share with them the conserved C-terminal glycine-glycine motif. Here, we report the solution structure of SAMP1 from Methanosarcina acetivorans and the activation of SAMPs by an archaeal protein with homology to eukaryotic E1 enzymes. Our results show that SAMP1 possesses a β-grasp fold and that its hydrophobic and electrostatic surface features are similar to those of MoaD. M. acetivorans SAMP1 exhibits an extensive flexible surface loop between helix-2 and the third strand of the β-sheet, which contributes to an elongated surface groove that is not observed in bacterial ubiquitin homologues and many other SAMPs. We provide in vitro biochemical evidence that SAMPs are activated in an ATP-dependent manner by an E1-like enzyme that we have termed E1-like SAMP activator (ELSA). We show that activation occurs by formation of a mixed anhydride (adenylate) at the SAMP C-terminus and is detectable by SDS-PAGE and electrospray ionization mass spectrometry.
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27
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Carraway KL. E3 ubiquitin ligases in ErbB receptor quantity control. Semin Cell Dev Biol 2010; 21:936-43. [PMID: 20868762 DOI: 10.1016/j.semcdb.2010.09.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2010] [Accepted: 09/15/2010] [Indexed: 02/08/2023]
Abstract
Signaling through ErbB family growth factor receptor tyrosine kinases is necessary for the development and homeostasis of a wide variety of tissue types. However, the intensity of receptor-mediated cellular signaling must fall within a precise range; insufficient signaling can lead to developmental abnormalities or tissue atrophy, while over-signaling can lead to hyperplastic and ultimately neoplastic events. While a plethora of mechanisms have been described that regulate downstream signaling events, it appears that cells also utilize various mechanisms to regulate their ErbB receptor levels. Such mechanisms are collectively termed "ErbB receptor quantity control." Notably, studies over the past few years have highlighted roles for post-transcriptional processes, particularly protein degradation, in ErbB quantity control. Here the involvement of ErbB-directed E3 ubiquitin ligases is discussed, including Nrdp1-mediated ErbB3 degradation, ErbB4 degradation mediated by Nedd4 family E3 ligases, and CHIP-mediated ErbB2 degradation. The hypothesis is forwarded that protein degradation-based ErbB quantity control mechanisms play central roles in suppressing receptor overexpression in normal cells, and that the loss of such mechanisms could facilitate the onset or progression of ErbB-dependent tumors.
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Survival defects of Cryptococcus neoformans mutants exposed to human cerebrospinal fluid result in attenuated virulence in an experimental model of meningitis. Infect Immun 2010; 78:4213-25. [PMID: 20696827 DOI: 10.1128/iai.00551-10] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cryptococcus neoformans is a fungal pathogen that encounters various microenvironments during growth in the mammalian host, including intracellular vacuoles, blood, and cerebrospinal fluid (CSF). Because the CSF is isolated by the blood-brain barrier, we hypothesize that CSF presents unique stresses that C. neoformans must overcome to establish an infection. We assayed 1,201 mutants for survival defects in growth media, saline, and human CSF. We assessed CSF-specific mutants for (i) mutant survival in both human bronchoalveolar lavage (BAL) fluid and fetal bovine serum (FBS), (ii) survival in macrophages, and (iii) virulence using both Caenorhabditis elegans and rabbit models of cryptococcosis. Thirteen mutants exhibited significant survival defects unique to CSF. The mutations of three of these mutants were recreated in the clinical serotype A strain H99: deletions of the genes for a cation ATPase transporter (ena1Δ), a putative NEDD8 ubiquitin-like protein (rub1Δ), and a phosphatidylinositol 4-kinase (pik1Δ). Mutant survival rates in yeast media, saline, and BAL fluid were similar to those of the wild type; however, survival in FBS was reduced but not to the levels in CSF. These mutant strains also exhibited decreased intracellular survival in macrophages, various degrees of virulence in nematodes, and severe attenuation of survival in a rabbit meningitis model. We analyzed the CSF by mass spectrometry for candidate compounds responsible for the survival defect. Our findings indicate that the genes required for C. neoformans survival in CSF ex vivo are necessary for survival and infection in this unique host environment.
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Application of an integrated physical and functional screening approach to identify inhibitors of the Wnt pathway. Mol Syst Biol 2009; 5:315. [PMID: 19888210 PMCID: PMC2779086 DOI: 10.1038/msb.2009.72] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2009] [Accepted: 09/08/2009] [Indexed: 01/15/2023] Open
Abstract
Large-scale proteomic approaches have been used to study signaling pathways. However, identification of biologically relevant hits from a single screen remains challenging due to limitations inherent in each individual approach. To overcome these limitations, we implemented an integrated, multi-dimensional approach and used it to identify Wnt pathway modulators. The LUMIER protein-protein interaction mapping method was used in conjunction with two functional screens that examined the effect of overexpression and siRNA-mediated gene knockdown on Wnt signaling. Meta-analysis of the three data sets yielded a combined pathway score (CPS) for each tested component, a value reflecting the likelihood that an individual protein is a Wnt pathway regulator. We characterized the role of two proteins with high CPSs, Ube2m and Nkd1. We show that Ube2m interacts with and modulates beta-catenin stability, and that the antagonistic effect of Nkd1 on Wnt signaling requires interaction with Axin, itself a negative pathway regulator. Thus, integrated physical and functional mapping in mammalian cells can identify signaling components with high confidence and provides unanticipated insights into pathway regulators.
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30
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Emerging roles of the ubiquitin proteasome system in nuclear hormone receptor signaling. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2009; 87:117-35. [PMID: 20374703 DOI: 10.1016/s1877-1173(09)87004-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Nuclear receptor (NR)-mediated transcription is intimately tied to the ubiquitin proteasome system (UPS). The UPS targets numerous NR and coregulator proteins, regulating their stability and altering their transcriptional activities through the posttranslational placement of ubiquitin marks on them. Differences in the manner in which ubiquitin is attached to target proteins or itself have distinct regulatory consequences. Protein monoubiquitination, polyubiquitination, the site of ubiquitin attachment to a target protein, and the type of polyubiquitin chain linkage all lead to different biological outcomes and have an important regulatory function in NR-mediated transcription. Consistent with its role in protein degradation, the UPS is able to limit the biological actions of both NRs and coregulators by reducing their protein concentrations in the cell. However, in spite of its destructive capabilities, the UPS can play a positive role in facilitating NR-mediated transcription as well. In addition, ubiquitin-like modifications such as SUMOylation also modify and regulate NRs and coregulators. The UPS forms a key biological system that underlies a sophisticated postranslational regulatory scheme from which complex and dynamic regulation of NR-mediated transcription can occur.
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31
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Abstract
The transcription factor p73, a member of the p53 family, mediates cell-cycle arrest and apoptosis in response to DNA damage-induced cellular stress, acting thus as a proapoptotic gene. Similar to p53, p73 activity is regulated by post-translational modification, including phosphorylation, acetylation and ubiquitylation. In C. elegans, the F-box protein FSN-1 controls germline apoptosis by regulating CEP-1, the single ancestral p53 family member. Here we report that FBXO45, the human ortholog of FSN-1, binds specifically to p73 triggering its proteasome-dependent degradation. Importantly, SCF(FBXO45) ubiquitylates p73 both in vivo and in vitro. Moreover, siRNA-mediated depletion of FBXO45 stabilizes p73 and concomitantly induces cell death in a p53-independent manner. All together, these results show that the orphan F-box protein FBXO45 regulates the stability of p73, highlighting a conserved pathway evolved from nematode to human by which the p53 members are regulated by an SCF-dependent mechanism.
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32
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Johnson JLFA, Lu C, Raharjo E, McNally K, McNally FJ, Mains PE. Levels of the ubiquitin ligase substrate adaptor MEL-26 are inversely correlated with MEI-1/katanin microtubule-severing activity during both meiosis and mitosis. Dev Biol 2009; 330:349-57. [PMID: 19361490 DOI: 10.1016/j.ydbio.2009.04.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2008] [Revised: 03/04/2009] [Accepted: 04/02/2009] [Indexed: 10/20/2022]
Abstract
The MEI-1/MEI-2 microtubule-severing complex, katanin, is required for oocyte meiotic spindle formation and function in C. elegans, but the microtubule-severing activity must be quickly downregulated so that it does not interfere with formation of the first mitotic spindle. Post-meiotic MEI-1 inactivation is accomplished by two parallel protein degradation pathways, one of which requires MEL-26, the substrate-specific adaptor that recruits MEI-1 to a CUL-3 based ubiquitin ligase. Here we address the question of how MEL-26 mediated MEI-1 degradation is triggered only after the completion of MEI-1's meiotic function. We find that MEL-26 is present only at low levels until the completion of meiosis, after which protein levels increase substantially, likely increasing the post-meiotic degradation of MEI-1. During meiosis, MEL-26 levels are kept low by the action of another type of ubiquitin ligase, which contains CUL-2. However, we find that the low levels of meiotic MEL-26 have a subtle function, acting to moderate MEI-1 activity during meiosis. We also show that MEI-1 is the only essential target for MEL-26, and possibly for the E3 ubiquitin ligase CUL-3, but the upstream ubiquitin ligase activating enzyme RFL-1 has additional essential targets.
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Affiliation(s)
- Jacque-Lynne F A Johnson
- Genes and Development Research Group, Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, AB, Canada T2N 4N1
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Nam S, Min K, Hwang H, Lee HO, Lee JH, Yoon J, Lee H, Park S, Lee J. Control of rapsyn stability by the CUL-3-containing E3 ligase complex. J Biol Chem 2009; 284:8195-206. [PMID: 19158078 PMCID: PMC3282941 DOI: 10.1074/jbc.m808230200] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2008] [Revised: 01/13/2009] [Indexed: 11/06/2022] Open
Abstract
Rapsyn is a postsynaptic protein required for clustering of nicotinic acetylcholine receptors (nAChRs) at the neuromuscular junction. Here we report the mechanism for posttranslational control of rapsyn protein stability. We confirmed that C18H9.7-encoded RPY-1 is a rapsyn homolog in Caenorhabditis elegans by showing that human rapsyn rescued rpy-1 mutant phenotypes in nematodes, as determined by levamisole assays and micropost array behavioral assays. We found that RPY-1 was degraded in the absence of functional UNC-29, a non-alpha subunit of the receptor, in an allele-specific manner, but not in the absence of other receptor subunits. The cytoplasmic loop of UNC-29 was found to be critical for RPY-1 stability. Through RNA interference screening, we found that UBC-1, UBC-12, NEDD-8, and RBX-1 were required for degradation of RPY-1. We identified cullin (CUL)-3 as a component of E3 ligase and KEL-8 as the substrate adaptor of RPY-1. Mammalian rapsyn was ubiquitinated by the CUL3/KLHL8-containing E3 ligase in vitro, and the knockdown of KLHL-8, a mammalian KEL-8 homolog, inhibited rapsyn ubiquitination in vivo, implying evolutionary conservation of the rapsyn stability control machinery. kel-8 suppression and rpy-1 overexpression in C. elegans produced a phenotype similar to that of a loss-of-function mutation of rpy-1, suggesting that control of rapsyn abundance is important for proper function of the receptor. Our results suggest a link between the control of rapsyn abundance and congenital myasthenic syndromes.
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Affiliation(s)
- Seunghee Nam
- Research Center for
Cellulomics, Institute of Molecular Biology and Genetics, School of Biological
Sciences, Seoul National University, 151-742 Seoul, Korea, the
Division of Nano Sciences (BK21),
Ewha Womans University, 120-750 Seoul, Korea,
Protein Network Research Center,
Department of Biochemistry, Yonsei University, 134 Shinchon, 120-749 Seoul,
Korea
| | - Kyoengwoo Min
- Research Center for
Cellulomics, Institute of Molecular Biology and Genetics, School of Biological
Sciences, Seoul National University, 151-742 Seoul, Korea, the
Division of Nano Sciences (BK21),
Ewha Womans University, 120-750 Seoul, Korea,
Protein Network Research Center,
Department of Biochemistry, Yonsei University, 134 Shinchon, 120-749 Seoul,
Korea
| | - Hyejin Hwang
- Research Center for
Cellulomics, Institute of Molecular Biology and Genetics, School of Biological
Sciences, Seoul National University, 151-742 Seoul, Korea, the
Division of Nano Sciences (BK21),
Ewha Womans University, 120-750 Seoul, Korea,
Protein Network Research Center,
Department of Biochemistry, Yonsei University, 134 Shinchon, 120-749 Seoul,
Korea
| | - Hae-ock Lee
- Research Center for
Cellulomics, Institute of Molecular Biology and Genetics, School of Biological
Sciences, Seoul National University, 151-742 Seoul, Korea, the
Division of Nano Sciences (BK21),
Ewha Womans University, 120-750 Seoul, Korea,
Protein Network Research Center,
Department of Biochemistry, Yonsei University, 134 Shinchon, 120-749 Seoul,
Korea
| | - Jung Hwa Lee
- Research Center for
Cellulomics, Institute of Molecular Biology and Genetics, School of Biological
Sciences, Seoul National University, 151-742 Seoul, Korea, the
Division of Nano Sciences (BK21),
Ewha Womans University, 120-750 Seoul, Korea,
Protein Network Research Center,
Department of Biochemistry, Yonsei University, 134 Shinchon, 120-749 Seoul,
Korea
| | - Jongbok Yoon
- Research Center for
Cellulomics, Institute of Molecular Biology and Genetics, School of Biological
Sciences, Seoul National University, 151-742 Seoul, Korea, the
Division of Nano Sciences (BK21),
Ewha Womans University, 120-750 Seoul, Korea,
Protein Network Research Center,
Department of Biochemistry, Yonsei University, 134 Shinchon, 120-749 Seoul,
Korea
| | - Hyunsook Lee
- Research Center for
Cellulomics, Institute of Molecular Biology and Genetics, School of Biological
Sciences, Seoul National University, 151-742 Seoul, Korea, the
Division of Nano Sciences (BK21),
Ewha Womans University, 120-750 Seoul, Korea,
Protein Network Research Center,
Department of Biochemistry, Yonsei University, 134 Shinchon, 120-749 Seoul,
Korea
| | - Sungsu Park
- Research Center for
Cellulomics, Institute of Molecular Biology and Genetics, School of Biological
Sciences, Seoul National University, 151-742 Seoul, Korea, the
Division of Nano Sciences (BK21),
Ewha Womans University, 120-750 Seoul, Korea,
Protein Network Research Center,
Department of Biochemistry, Yonsei University, 134 Shinchon, 120-749 Seoul,
Korea
| | - Junho Lee
- Research Center for
Cellulomics, Institute of Molecular Biology and Genetics, School of Biological
Sciences, Seoul National University, 151-742 Seoul, Korea, the
Division of Nano Sciences (BK21),
Ewha Womans University, 120-750 Seoul, Korea,
Protein Network Research Center,
Department of Biochemistry, Yonsei University, 134 Shinchon, 120-749 Seoul,
Korea
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Kumar A, Wu H, Collier-Hyams LS, Kwon YM, Hanson JM, Neish AS. The bacterial fermentation product butyrate influences epithelial signaling via reactive oxygen species-mediated changes in cullin-1 neddylation. THE JOURNAL OF IMMUNOLOGY 2009; 182:538-46. [PMID: 19109186 DOI: 10.4049/jimmunol.182.1.538] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The human enteric flora plays a significant role in intestinal health and disease. Populations of enteric bacteria can inhibit the NF-kappaB pathway by blockade of IkappaB-alpha ubiquitination, a process catalyzed by the E3-SCF(beta-TrCP) ubiquitin ligase. The activity of this ubiquitin ligase is regulated via covalent modification of the Cullin-1 subunit by the ubiquitin-like protein NEDD8. We previously reported that interaction of viable commensal bacteria with mammalian intestinal epithelial cells resulted in a rapid and reversible generation of reactive oxygen species (ROS) that modulated neddylation of Cullin-1 and resulted in suppressive effects on the NF-kappaB pathway. Herein, we demonstrate that butyrate and other short chain fatty acids supplemented to model human intestinal epithelia in vitro and human tissue ex vivo results in loss of neddylated Cul-1 and show that physiological concentrations of butyrate modulate the ubiquitination and degradation of a target of the E3- SCF(beta-TrCP) ubiquitin ligase, the NF-kappaB inhibitor IkappaB-alpha. Mechanistically, we show that physiological concentrations of butyrate induces reactive oxygen species that transiently alters the intracellular redox balance and results in inactivation of the NEDD8-conjugating enzyme Ubc12 in a manner similar to effects mediated by viable bacteria. Because the normal flora produces significant amounts of butyrate and other short chain fatty acids, these data provide a functional link between a natural product of the intestinal normal flora and important epithelial inflammatory and proliferative signaling pathways.
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Affiliation(s)
- Amrita Kumar
- Department of Pathology and Laboratory Medicine, Epithelial Pathobiology Unit, Emory University School of Medicine, Atlanta, GA 30322, USA
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Todi SV, Winborn BJ, Scaglione KM, Blount JR, Travis SM, Paulson HL. Ubiquitination directly enhances activity of the deubiquitinating enzyme ataxin-3. EMBO J 2009; 28:372-82. [PMID: 19153604 DOI: 10.1038/emboj.2008.289] [Citation(s) in RCA: 136] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2008] [Accepted: 12/15/2008] [Indexed: 11/09/2022] Open
Abstract
Deubiquitinating enzymes (DUBs) control the ubiquitination status of proteins in various cellular pathways. Regulation of the activity of DUBs, which is critically important to cellular homoeostasis, can be achieved at the level of gene expression, protein complex formation, or degradation. Here, we report that ubiquitination also directly regulates the activity of a DUB, ataxin-3, a polyglutamine disease protein implicated in protein quality control pathways. Ubiquitination enhances ubiquitin (Ub) chain cleavage by ataxin-3, but does not alter its preference for K63-linked Ub chains. In cells, ubiquitination of endogenous ataxin-3 increases when the proteasome is inhibited, when excess Ub is present, or when the unfolded protein response is induced, suggesting that the cellular functions of ataxin-3 in protein quality control are modulated through ubiquitination. Ataxin-3 is the first reported DUB in which ubiquitination directly regulates catalytic activity. We propose a new function for protein ubiquitination in regulating the activity of certain DUBs and perhaps other enzymes.
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Affiliation(s)
- Sokol V Todi
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA
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36
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Stuttmann J, Lechner E, Guérois R, Parker JE, Nussaume L, Genschik P, Noël LD. COP9 signalosome- and 26S proteasome-dependent regulation of SCFTIR1 accumulation in Arabidopsis. J Biol Chem 2009; 284:7920-30. [PMID: 19147500 DOI: 10.1074/jbc.m809069200] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Ubiquitination and proteasome-mediated degradation of proteins are crucial for eukaryotic physiology and development. The largest class of E3 ubiquitin ligases is made up of the cullin-RING ligases (CRLs), which themselves are positively regulated through conjugation of the ubiquitin-like peptide RUB/NEDD8 to cullins. RUB modification is antagonized by the COP9 signalosome (CSN), an evolutionarily conserved eight-subunit complex that is essential in most eukaryotes and cleaves RUB from cullins. The CSN behaves genetically as an activator of CRLs, although it abolishes CRL activity in vitro. This apparent paradox was recently reconciled in different organisms, as the CSN was shown to prevent autocatalytic degradation of several CRL substrate adaptors. We tested for such a mechanism in the model plant Arabidopsis by measuring the impact of a newly identified viable csn2 mutant on the activity and stability of SCF(TIR1), a receptor to the phytohormone auxin and probably the best characterized plant CRL. Our analysis reveals that not only the F-box protein TIR1 but also relevant cullins are destabilized in csn2 and other Arabidopsis csn mutants. These results provide an explanation for the auxin resistance of csn mutants. We further observed in vivo a post-translational modification of TIR1 dependent on the proteasome inhibitor MG-132 and provide evidence for proteasome-mediated degradation of TIR1, CUL1, and ASK1 (Arabidopsis SKP1 homolog). These results are consistent with CSN-dependent protection of Arabidopsis CRLs from autocatalytic degradation, as observed in other eukaryotes, and provide evidence for antagonist roles of the CSN and 26S proteasome in modulating accumulation of the plant CRL SCF(TIR1).
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Affiliation(s)
- Johannes Stuttmann
- Institut de Biologie Environnementale et Biotechnologie, UMR 6191, CNRS-Commissariat à l'Energie Atomique, UniversitédelaMéditerranée Aix-Marseille II, Centre d'Etudes Nucléaires Cadarache, F-13108 Saint Paul lez Durance Cedex, France
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Hayashi KI, Kamio S, Oono Y, Townsend LB, Nozaki H. Toyocamycin specifically inhibits auxin signaling mediated by SCFTIR1 pathway. PHYTOCHEMISTRY 2009; 70:190-197. [PMID: 19171357 DOI: 10.1016/j.phytochem.2008.12.020] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2008] [Revised: 11/25/2008] [Accepted: 12/16/2008] [Indexed: 05/27/2023]
Abstract
The auxins, plant hormones, play a crucial role in many aspects of plant development by regulating cell division, elongation and differentiation. Toyocamycin, a nucleoside-type antibiotic, was identified as auxin signaling inhibitor in a screen of microbial extracts for inhibition of the auxin-inducible reporter gene assay. Toyocamycin specifically inhibited auxin-responsive gene expression, but did not affect other hormone-inducible gene expression. Toyocamycin also blocked auxin-enhanced degradation of the Aux/IAA repressor modulated by the SCF(TIR1) ubiquitin-proteasome pathway without inhibiting proteolytic activity of proteasome. Furthermore, toyocamycin inhibited auxin-induced lateral root formation and epinastic growth of cotyledon in the Arabidopsis thaliana plant. This evidence suggested that toyocamycin would act on the ubiquitination process regulated by SCF(TIR1) machineries. To address the structural requirements for the specific activity of toyocamycin on auxin signaling, the structure-activity relationships of nine toyocamycin-related compounds, including sangivamycin and tubercidin, were investigated.
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Affiliation(s)
- Ken-ichiro Hayashi
- Department of Biochemistry, Okayama University of Science, 1-1 Ridai-cho, Okayama City 700-0005, Japan.
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Affiliation(s)
| | - Mark Estelle
- Department of Biology, Indiana University, Bloomington, Indiana 47405; ,
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40
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Function and regulation of protein neddylation. 'Protein modifications: beyond the usual suspects' review series. EMBO Rep 2008; 9:969-76. [PMID: 18802447 DOI: 10.1038/embor.2008.183] [Citation(s) in RCA: 272] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2008] [Accepted: 08/25/2008] [Indexed: 12/16/2022] Open
Abstract
Neddylation is the post-translational protein modification that is most closely related to ubiquitination. However, ubiquitination is known to regulate a myriad of processes in eukaryotic cells, whereas only a limited number of neddylation substrates have been described to date. Here, we review the principles of protein neddylation and highlight the mechanisms that ensure the specificity of neddylation over ubiquitination. As numerous neddylation substrates probably remain to be discovered, we propose some criteria that could be used as guidelines for the characterization of neddylated proteins.
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Drew RE, Rodnick KJ, Settles M, Wacyk J, Churchill E, Powell MS, Hardy RW, Murdoch GK, Hill RA, Robison BD. Effect of starvation on transcriptomes of brain and liver in adult female zebrafish (Danio rerio). Physiol Genomics 2008; 35:283-95. [PMID: 18728227 DOI: 10.1152/physiolgenomics.90213.2008] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We used microarray and quantitative real-time PCR (qRT-PCR) analyses in adult female zebrafish (Danio rerio) to identify metabolic pathways regulated by starvation in the liver and brain. The transcriptome of whole zebrafish brain showed little response to 21 days of starvation. Only agouti-related protein 1 (agrp1) significantly responded, with increased expression in brains of starved fish. In contrast, a 21-day period of starvation significantly downregulated 466 and upregulated 108 transcripts in the liver, indicating an overall decrease in metabolic activity, reduced lipid metabolism, protein biosynthesis, proteolysis, and cellular respiration, and increased gluconeogenesis. Starvation also regulated expression of many components of the unfolded protein response, the first such report in a species other than yeast (Saccharomyces cerevisiae) and mice (Mus musculus). The response of the zebrafish hepatic transcriptome to starvation was strikingly similar to that of rainbow trout (Oncorhynchus mykiss) and less similar to mouse, while the response of common carp (Cyprinus carpio) differed considerably from the other three species.
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Affiliation(s)
- Robert E Drew
- Department of Biological Sciences and Initiative for Bioinformatics and Evolutionary Studies, University of Idaho, Moscow
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Molinier J, Lechner E, Dumbliauskas E, Genschik P. Regulation and role of Arabidopsis CUL4-DDB1A-DDB2 in maintaining genome integrity upon UV stress. PLoS Genet 2008; 4:e1000093. [PMID: 18551167 PMCID: PMC2396500 DOI: 10.1371/journal.pgen.1000093] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2008] [Accepted: 05/12/2008] [Indexed: 11/18/2022] Open
Abstract
Plants use the energy in sunlight for photosynthesis, but as a consequence are exposed to the toxic effect of UV radiation especially on DNA. The UV-induced lesions on DNA affect both transcription and replication and can also have mutagenic consequences. Here we investigated the regulation and the function of the recently described CUL4-DDB1-DDB2 E3 ligase in the maintenance of genome integrity upon UV-stress using the model plant Arabidopsis. Physiological, biochemical, and genetic evidences indicate that this protein complex is involved in global genome repair (GGR) of UV-induced DNA lesions. Moreover, we provide evidences for crosstalks between GGR, the plant-specific photo reactivation pathway and the RAD1-RAD10 endonucleases upon UV exposure. Finally, we report that DDB2 degradation upon UV stress depends not only on CUL4, but also on the checkpoint protein kinase Ataxia telangiectasia and Rad3-related (ATR). Interestingly, we found that DDB1A shuttles from the cytoplasm to the nucleus in an ATR-dependent manner, highlighting an upstream level of control and a novel mechanism of regulation of this E3 ligase.
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Affiliation(s)
- Jean Molinier
- Institut de Biologie Moléculaire des Plantes du CNRS (UPR2357), conventionné avec l'Université Louis Pasteur, Strasbourg, France
| | - Esther Lechner
- Institut de Biologie Moléculaire des Plantes du CNRS (UPR2357), conventionné avec l'Université Louis Pasteur, Strasbourg, France
| | - Eva Dumbliauskas
- Institut de Biologie Moléculaire des Plantes du CNRS (UPR2357), conventionné avec l'Université Louis Pasteur, Strasbourg, France
| | - Pascal Genschik
- Institut de Biologie Moléculaire des Plantes du CNRS (UPR2357), conventionné avec l'Université Louis Pasteur, Strasbourg, France
- * E-mail:
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Ren H, Santner A, del Pozo JC, Murray JAH, Estelle M. Degradation of the cyclin-dependent kinase inhibitor KRP1 is regulated by two different ubiquitin E3 ligases. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2008; 53:705-16. [PMID: 18005227 DOI: 10.1111/j.1365-313x.2007.03370.x] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
In animals and fungi, a group of proteins called the cyclin-dependent kinase inhibitors play a key role in cell cycle regulation. However, comparatively little is known about the role of these proteins in plant cell cycle regulation. To gain insight into the mechanisms by which the plant cell cycle is regulated, we studied the cyclin-dependent kinase inhibitor KRP1 in Arabidopsis. KRP1 interacts with the CDKA;1/CYCD2;1 complex in planta and functions in the G1-S transition of the cell cycle. Furthermore, we show that KRP1 is a likely target of the ubiquitin/proteasome pathway. Two different ubiquitin protein ligases, SCF(SKP2) and the RING protein RKP, contribute to its degradation. These results suggest that SCF(SKP2b) and RPK play an important role in the cell cycle through regulating KRP1 protein turnover.
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Affiliation(s)
- Hong Ren
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
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Sumara I, Maerki S, Peter M. E3 ubiquitin ligases and mitosis: embracing the complexity. Trends Cell Biol 2008; 18:84-94. [PMID: 18215523 DOI: 10.1016/j.tcb.2007.12.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2007] [Revised: 12/03/2007] [Accepted: 12/03/2007] [Indexed: 11/17/2022]
Abstract
Faithful division of eukaryotic cells requires temporal and spatial coordination of morphological transitions, which ensures that the newly replicated copies of the genome are equally distributed into the two daughter cells during mitosis. One of the mechanisms ensuring the fidelity of mitotic progression is targeted, ubiquitin-dependent proteolysis of key regulators. E3-ubiquitin ligase complexes are crucial components in this pathway because they specifically select the relevant ubiquitination substrates. Cullin-based E3-ligases, such as Cul3, have recently emerged as crucial regulators of mitosis.
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Affiliation(s)
- Izabela Sumara
- Institute of Biochemistry, HPM G 8, ETH Hönggerberg, Schafmattstrasse 18, 8093 Zurich, Switzerland.
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Lee Y, Lee HS, Lee JS, Kim SK, Kim SH. Hormone- and light-regulated nucleocytoplasmic transport in plants: current status. JOURNAL OF EXPERIMENTAL BOTANY 2008; 59:3229-45. [PMID: 18678754 DOI: 10.1093/jxb/ern200] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The gene regulation mechanisms underlying hormone- and light-induced signal transduction in plants rely not only on post-translational modification and protein degradation, but also on selective inclusion and exclusion of proteins from the nucleus. For example, plant cells treated with light or hormones actively transport many signalling regulatory proteins, transcription factors, and even photoreceptors and hormone receptors into the nucleus, while actively excluding other proteins. The nuclear envelope (NE) is the physical and functional barrier that mediates this selective partitioning, and nuclear transport regulators transduce hormone- or light-initiated signalling pathways across the membrane to mediate nuclear activities. Recent reports revealed that mutating the proteins regulating nuclear transport through the pores, such as nucleoporins, alters the plant's response to a stimulus. In this review, recent works are introduced that have revealed the importance of regulated nucleocytoplasmic partitioning. These important findings deepen our understanding about how co-ordinated plant hormone and light signal transduction pathways facilitate communication between the cytoplasm and the nucleus. The roles of nucleoporin components within the nuclear pore complex (NPC) are also emphasized, as well as nuclear transport cargo, such as Ran/TC4 and its binding proteins (RanBPs), in this process. Recent findings concerning these proteins may provide a possible direction by which to characterize the regulatory potential of hormone- or light-triggered nuclear transport.
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Affiliation(s)
- Yew Lee
- Department of Biological Sciences, Yonsei University, 234 Heungup-Myun, Wonju-Si, 220-710, Korea
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Abstract
The ubiquitin/26S proteasome pathway largely mediates selective proteolysis in the nucleus and cytosol. This pathway catalyzes covalent attachment of ubiquitin (UBQ) to substrate proteins in an E1-E2-E3 cascade. Ubiquitin E3 ligases interact with substrates to catalyze UBQ transfer from E2 to substrate. Within the E3 ligase superfamily, cullin RING ligases (CRLs) are significant in plants because they are linked to hormonal signaling, developmental programs, and environmental responses. Thus, knowledge of CRL regulation is required for a complete understanding of these processes. A major mechanism modulating CRL activity is modification of the cullin subunit by RUB (RELATED TO UBIQUITIN), a ubiquitin-like protein, and demodification by the COP9 signalosome (CSN). CULLIN-ASSOCIATED NEDD8-DISSOCIATED 1 (CAND1) interacts with CRLs, affecting both rubylation and derubylation. Described here are the pathways, regulation, and biological function of rubylation and derubylation, as well as future directions and outstanding questions.
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Affiliation(s)
- Sara K Hotton
- Section of Molecular and Cellular Biology, University of California, Davis, California 95616, USA.
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Ferro A, Carvalho AL, Teixeira-Castro A, Almeida C, Tomé RJ, Cortes L, Rodrigues AJ, Logarinho E, Sequeiros J, Macedo-Ribeiro S, Maciel P. NEDD8: A new ataxin-3 interactor. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2007; 1773:1619-27. [DOI: 10.1016/j.bbamcr.2007.07.012] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2007] [Revised: 07/13/2007] [Accepted: 07/23/2007] [Indexed: 10/22/2022]
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Kumar A, Wu H, Collier-Hyams LS, Hansen JM, Li T, Yamoah K, Pan ZQ, Jones DP, Neish AS. Commensal bacteria modulate cullin-dependent signaling via generation of reactive oxygen species. EMBO J 2007; 26:4457-66. [PMID: 17914462 PMCID: PMC2063476 DOI: 10.1038/sj.emboj.7601867] [Citation(s) in RCA: 221] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2007] [Accepted: 09/05/2007] [Indexed: 12/17/2022] Open
Abstract
The resident prokaryotic microflora of the mammalian intestine influences diverse homeostatic functions of the gut, including regulation of cellular growth and immune responses; however, it is unknown how commensal prokaryotic organisms mechanistically influence eukaryotic signaling networks. We have shown that bacterial coculture with intestinal epithelial cells modulates ubiquitin-mediated degradation of important signaling intermediates, including beta-catenin and the NF-kappaB inhibitor IkappaB-alpha. Ubiquitination of these proteins as well as others is catalyzed by the SCF(betaTrCP) ubiquitin ligase, which itself requires regulated modification of the cullin-1 subunit by the ubiquitin-like protein NEDD8. Here we show that epithelia contacted by enteric commensal bacteria in vitro and in vivo rapidly generate reactive oxygen species (ROS). Bacterially induced ROS causes oxidative inactivation of the catalytic cysteine residue of Ubc12, the NEDD8-conjugating enzyme, resulting in complete but transient loss of cullin-1 neddylation and consequent effects on NF-kappaB and beta-catenin signaling. Our results demonstrate that commensal bacteria directly modulate a critical control point of the ubiquitin-proteasome system, and suggest how enteric commensal bacterial flora influences the regulatory pathways of the mammalian intestinal epithelia.
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Affiliation(s)
- Amrita Kumar
- Epithelial Pathobiology Unit, Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA, USA
| | - Huixia Wu
- Epithelial Pathobiology Unit, Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA, USA
| | - Lauren S Collier-Hyams
- Epithelial Pathobiology Unit, Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA, USA
| | - Jason M Hansen
- Division of Pulmonary, Asthma, Cystic Fibrosis and Sleep, Department of Pediatrics, Emory University, Atlanta, GA, USA
| | - Tengguo Li
- Department of Biology, Emory University, Atlanta, GA, USA
| | - Kosj Yamoah
- Department of Oncological Sciences, Mount Sinai School of Medicine, New York, NY, USA
| | - Zhen-Qiang Pan
- Department of Oncological Sciences, Mount Sinai School of Medicine, New York, NY, USA
| | - Dean P Jones
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, Emory University, Atlanta, GA, USA
| | - Andrew S Neish
- Epithelial Pathobiology Unit, Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA, USA
- Epithelial Pathobiology Unit, Department of Pathology, Emory University School of Medicine, Room 105-F, Whitehead Bldg, 615 Michael Street, Atlanta, GA 30322, USA. Tel.: +1 404 727 8545; Fax: +1 404 727 8538; E-mail:
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Yang Y, Kitagaki J, Dai RM, Tsai YC, Lorick KL, Ludwig RL, Pierre SA, Jensen JP, Davydov IV, Oberoi P, Li CCH, Kenten JH, Beutler JA, Vousden KH, Weissman AM. Inhibitors of Ubiquitin-Activating Enzyme (E1), a New Class of Potential Cancer Therapeutics. Cancer Res 2007; 67:9472-81. [PMID: 17909057 DOI: 10.1158/0008-5472.can-07-0568] [Citation(s) in RCA: 339] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The conjugation of proteins with ubiquitin plays numerous regulatory roles through both proteasomal-dependent and nonproteasomal-dependent functions. Alterations in ubiquitylation are observed in a wide range of pathologic conditions, including numerous malignancies. For this reason, there is great interest in targeting the ubiquitin-proteasome system in cancer. Several classes of proteasome inhibitors, which block degradation of ubiquitylated proteins, are widely used in research, and one, Bortezomib, is now in clinical use. Despite the well-defined and central role of the ubiquitin-activating enzyme (E1), no cell permeable inhibitors of E1 have been identified. Such inhibitors should, in principle, block all functions of ubiquitylation. We now report 4[4-(5-nitro-furan-2-ylmethylene)-3,5-dioxo-pyrazolidin-1-yl]-benzoic acid ethyl ester (PYR-41) as the first such inhibitor. Unexpectedly, in addition to blocking ubiquitylation, PYR-41 increased total sumoylation in cells. The molecular basis for this is unknown; however, increased sumoylation was also observed in cells harboring temperature-sensitive E1. Functionally, PYR-41 attenuates cytokine-mediated nuclear factor-kappaB activation. This correlates with inhibition of nonproteasomal (Lys-63) ubiquitylation of TRAF6, which is essential to IkappaB kinase activation. PYR-41 also prevents the downstream ubiquitylation and proteasomal degradation of IkappaBalpha. Furthermore, PYR-41 inhibits degradation of p53 and activates the transcriptional activity of this tumor suppressor. Consistent with this, it differentially kills transformed p53-expressing cells. Thus, PYR-41 and related pyrazones provide proof of principle for the capacity to differentially kill transformed cells, suggesting the potential for E1 inhibitors as therapeutics in cancer. These inhibitors can also be valuable tools for studying ubiquitylation.
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Affiliation(s)
- Yili Yang
- Laboratory of Protein Dynamics and Signaling, Center for Cancer Research, National Cancer Institute at Frederick, NIH, Frederick, Maryland 21702, USA.
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Yang P, Smalle J, Lee S, Yan N, Emborg TJ, Vierstra RD. Ubiquitin C-terminal hydrolases 1 and 2 affect shoot architecture in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2007; 51:441-57. [PMID: 17559514 DOI: 10.1111/j.1365-313x.2007.03154.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Ubiquitin C-terminal hydrolases (UCHs) are a subset of de-ubiquitinating proteases that release covalently linked ubiquitin (Ub), and as such play essential roles in recycling Ub and reversing the action of Ub conjugation. We show here that two related Arabidopsis UCHs, UCH1, and UCH2, are important for shoot development. The UCH1 and 2 genes are ubiquitously expressed, with the corresponding proteins present in both the cytoplasm and nucleus. Unlike their animal and fungal counterparts, we found no evidence that the Arabidopsis UCH1 and 2 proteins stably associate with the 26S proteasome. Altering the levels of UCH1 and 2 has substantial effects on Arabidopsis shoot development, especially with respect to inflorescence architecture, with over-expression and double mutants enhancing and suppressing the outgrowth of cauline branches, respectively. Neither UCH1-over-expressing nor uch1-1 uch2-1 plants have detectably altered sensitivity to cytokinins or auxins individually, but exhibit an altered sensitivity to the ratio of the two hormones. UCH1-over-expressing plants show dramatically enhanced phenotypes when combined with auxin-insensitive mutants axr1-3 and axr2-1, suggesting that one or more aspects of auxin signaling are affected by this enzyme pair. Previous studies revealed that the ubiquitination and degradation of the AUX/IAA family of repressors is a key step in auxin signaling. Here, we show that turnover of a reporter fused to a representative AUX/IAA protein AXR3 is faster in the uch1-1 uch2-1 double mutant but slower in the UCH1 over-expression backgrounds. Taken together, our results indicate that de-ubiquitination helps to modify plant shoot architecture, possibly via its ability to directly or indirectly protect upstream target proteins involved in auxin/cytokinin signaling from Ub-mediated degradation.
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Affiliation(s)
- Peizhen Yang
- Department of Genetics, University of Wisconsin-Madison, Madison, WI 53706-1574, USA
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