51
|
Rahimi H, Ahmadzadeh A, Yousef-amoli S, Kokabee L, Shokrgozar MA, Mahdian R, Karimipoor M. The expression pattern of APC2 and APC7 in various cancer cell lines and AML patients. Adv Med Sci 2015; 60:259-63. [PMID: 26046517 DOI: 10.1016/j.advms.2015.04.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 03/11/2015] [Accepted: 04/30/2015] [Indexed: 01/29/2023]
Abstract
PURPOSE Anaphase promoting complex (APC/C) is an E3 ligase enzyme, which ubiquinates various proteins involved in the cell cycle. This protein complex may have a pivotal role in the cell cycle control affecting pathological conditions such as cancer. APC7 and APC2 subunits of the APC/C complex are involved in the substrate recognition and the catalytic reaction, respectively. MATERIALS AND METHODS In this study, quantitative Real-time PCR was used to analyse APC2 and APC7 expression in different cancer cell lines as well as AML patient's blood cells. RESULTS The results showed that APC2 and APC7 subunits were both over expressed in cancer cell lines (p=0.008). The mean expression ratio of APC2 and APC7 in different cancer cells were 2.60±0.22 and 4.83±0.11, respectively. An increase in expression of APC2 and APC7 was seen among 12 out of 14 AML patients (85%). There was a significant positive correlation between APC2 upregulation and the detection of splenomegaly in the patients (r=0.808, p=0.001). CONCLUSION This was the first study suggesting that APC/C upregulation may contribute to the pathogenesis of cancer and can be used as a molecular biomarker to predict the progression and the prognosis of AML.
Collapse
Affiliation(s)
- Hamzeh Rahimi
- Molecular Medicine Department, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | - Ahmad Ahmadzadeh
- Thalassemia and Hemoglobinopathy Research Center, Shafa Hospital, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Shamseddin Yousef-amoli
- Molecular Medicine Department, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | - Leila Kokabee
- Molecular Medicine Department, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | | | - Reza Mahdian
- Molecular Medicine Department, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran.
| | - Mortaza Karimipoor
- Molecular Medicine Department, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran.
| |
Collapse
|
52
|
Targeting Cullin-RING E3 ubiquitin ligases for drug discovery: structure, assembly and small-molecule modulation. Biochem J 2015; 467:365-86. [PMID: 25886174 PMCID: PMC4403949 DOI: 10.1042/bj20141450] [Citation(s) in RCA: 160] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
In the last decade, the ubiquitin–proteasome system has emerged as a valid target for the development of novel therapeutics. E3 ubiquitin ligases are particularly attractive targets because they confer substrate specificity on the ubiquitin system. CRLs [Cullin–RING (really interesting new gene) E3 ubiquitin ligases] draw particular attention, being the largest family of E3s. The CRLs assemble into functional multisubunit complexes using a repertoire of substrate receptors, adaptors, Cullin scaffolds and RING-box proteins. Drug discovery targeting CRLs is growing in importance due to mounting evidence pointing to significant roles of these enzymes in diverse biological processes and human diseases, including cancer, where CRLs and their substrates often function as tumour suppressors or oncogenes. In the present review, we provide an account of the assembly and structure of CRL complexes, and outline the current state of the field in terms of available knowledge of small-molecule inhibitors and modulators of CRL activity. A comprehensive overview of the reported crystal structures of CRL subunits, components and full-size complexes, alone or with bound small molecules and substrate peptides, is included. This information is providing increasing opportunities to aid the rational structure-based design of chemical probes and potential small-molecule therapeutics targeting CRLs.
Collapse
|
53
|
Chen M, Hu C, Zhang R, Jiang F, Wang J, Peng D, Tang S, Sun X, Yan J, Wang S, Wang T, Bao Y, Jia W. A variant of PSMD6 is associated with the therapeutic efficacy of oral antidiabetic drugs in Chinese type 2 diabetes patients. Sci Rep 2015; 5:10701. [PMID: 26024304 PMCID: PMC4448652 DOI: 10.1038/srep10701] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 04/27/2015] [Indexed: 12/31/2022] Open
Abstract
The PSMD6 variant rs831571 has been identified as a susceptibility locus for type 2 diabetes mellitus (T2DM). This study aimed to investigate the association of this variant with therapeutic effects of oral antidiabetic drugs in Chinese T2DM patients. 209 newly diagnosed T2DM patients were randomly assigned to treatment with repaglinide or rosiglitazone for 48 weeks, and the therapeutic effects were compared. In the rosiglitazone cohort, rs831571 showed significant associations with fasting plasma glucose (FPG), 2-h glucose and decrement of glycated haemoglobin (HbA1c) levels after 24 weeks of treatment (P = 0.0368, 0.0468 and 0.0247, respectively). The C allele was significantly associated with a better attainment of FPG at 24 and 32 weeks (P = 0.0172 and 0.0257, respectively). Survival analyses showed CC homozygotes were more likely to attain a standard FPG level (P = 0.0654). In the repaglinide cohort, rs831571 was significantly associated with decreased HbA1c levels after 24 weeks of treatment, the homeostatic model assessment of insulin resistance and fasting insulin level after 48 weeks of treatment with repaglinide (P = 0.0096, 0235 and 0.0212, respectively). In conclusion, we observed that the PSMD6 variant rs831571 might be associated with the therapeutic effects of rosiglitazone and repaglinide in Chinese T2DM patients. However, these findings need to be confirmed in the future.
Collapse
Affiliation(s)
- Miao Chen
- Shanghai Diabetes Institute, Department of Endocrinology and Metabolism, Shanghai Clinical Center for Diabetes, Shanghai Key Clinical Center for Metabolic Disease, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai, China
| | - Cheng Hu
- 1] Shanghai Diabetes Institute, Department of Endocrinology and Metabolism, Shanghai Clinical Center for Diabetes, Shanghai Key Clinical Center for Metabolic Disease, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai, China [2] Shanghai Jiao Tong University Affiliated Sixth People's Hospital South Campus, Shanghai, China
| | - Rong Zhang
- Shanghai Diabetes Institute, Department of Endocrinology and Metabolism, Shanghai Clinical Center for Diabetes, Shanghai Key Clinical Center for Metabolic Disease, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai, China
| | - Feng Jiang
- Shanghai Diabetes Institute, Department of Endocrinology and Metabolism, Shanghai Clinical Center for Diabetes, Shanghai Key Clinical Center for Metabolic Disease, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai, China
| | - Jie Wang
- Shanghai Diabetes Institute, Department of Endocrinology and Metabolism, Shanghai Clinical Center for Diabetes, Shanghai Key Clinical Center for Metabolic Disease, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai, China
| | - Danfeng Peng
- Shanghai Diabetes Institute, Department of Endocrinology and Metabolism, Shanghai Clinical Center for Diabetes, Shanghai Key Clinical Center for Metabolic Disease, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai, China
| | - Shanshan Tang
- Shanghai Diabetes Institute, Department of Endocrinology and Metabolism, Shanghai Clinical Center for Diabetes, Shanghai Key Clinical Center for Metabolic Disease, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai, China
| | - Xue Sun
- Shanghai Diabetes Institute, Department of Endocrinology and Metabolism, Shanghai Clinical Center for Diabetes, Shanghai Key Clinical Center for Metabolic Disease, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai, China
| | - Jing Yan
- Shanghai Diabetes Institute, Department of Endocrinology and Metabolism, Shanghai Clinical Center for Diabetes, Shanghai Key Clinical Center for Metabolic Disease, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai, China
| | - Shiyun Wang
- Shanghai Diabetes Institute, Department of Endocrinology and Metabolism, Shanghai Clinical Center for Diabetes, Shanghai Key Clinical Center for Metabolic Disease, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai, China
| | - Tao Wang
- Shanghai Diabetes Institute, Department of Endocrinology and Metabolism, Shanghai Clinical Center for Diabetes, Shanghai Key Clinical Center for Metabolic Disease, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai, China
| | - Yuqian Bao
- Shanghai Diabetes Institute, Department of Endocrinology and Metabolism, Shanghai Clinical Center for Diabetes, Shanghai Key Clinical Center for Metabolic Disease, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai, China
| | - Weiping Jia
- Shanghai Diabetes Institute, Department of Endocrinology and Metabolism, Shanghai Clinical Center for Diabetes, Shanghai Key Clinical Center for Metabolic Disease, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai, China
| |
Collapse
|
54
|
First EA. A continuous spectrophotometric assay for monitoring adenosine 5'-monophosphate production. Anal Biochem 2015; 483:34-9. [PMID: 25957126 DOI: 10.1016/j.ab.2015.04.032] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Revised: 04/24/2015] [Accepted: 04/27/2015] [Indexed: 11/18/2022]
Abstract
A number of biologically important enzymes release adenosine 5'-monophosphate (AMP) as a product, including aminoacyl-tRNA synthetases, cyclic AMP (cAMP) phosphodiesterases, ubiquitin and ubiquitin-like ligases, DNA ligases, coenzyme A (CoA) ligases, polyA deadenylases, and ribonucleases. In contrast to the abundance of assays available for monitoring the conversion of adenosine 5'-triphosphate (ATP) to ADP, there are relatively few assays for monitoring the conversion of ATP (or cAMP) to AMP. In this article, we describe a homogeneous assay that continuously monitors the production of AMP. Specifically, we have coupled the conversion of AMP to inosine 5'-monophosphate (IMP) (by AMP deaminase) to the oxidation of IMP (by IMP dehydrogenase). This results in the reduction of oxidized nicotine adenine dinucleotide (NAD(+)) to reduced nicotine adenine dinucleotide (NADH), allowing AMP formation to be monitored by the change in the absorbance at 340 nm. Changes in AMP concentrations of 5 μM or more can be reliably detected. The ease of use and relatively low expense make the AMP assay suitable for both high-throughput screening and kinetic analyses.
Collapse
Affiliation(s)
- Eric A First
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center in Shreveport, Shreveport, LA 71130, USA.
| |
Collapse
|
55
|
McIntyre J, Woodgate R. Regulation of translesion DNA synthesis: Posttranslational modification of lysine residues in key proteins. DNA Repair (Amst) 2015; 29:166-79. [PMID: 25743599 PMCID: PMC4426011 DOI: 10.1016/j.dnarep.2015.02.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Revised: 02/09/2015] [Accepted: 02/10/2015] [Indexed: 01/30/2023]
Abstract
Posttranslational modification of proteins often controls various aspects of their cellular function. Indeed, over the past decade or so, it has been discovered that posttranslational modification of lysine residues plays a major role in regulating translesion DNA synthesis (TLS) and perhaps the most appreciated lysine modification is that of ubiquitination. Much of the recent interest in ubiquitination stems from the fact that proliferating cell nuclear antigen (PCNA) was previously shown to be specifically ubiquitinated at K164 and that such ubiquitination plays a key role in regulating TLS. In addition, TLS polymerases themselves are now known to be ubiquitinated. In the case of human polymerase η, ubiquitination at four lysine residues in its C-terminus appears to regulate its ability to interact with PCNA and modulate TLS. Within the past few years, advances in global proteomic research have revealed that many proteins involved in TLS are, in fact, subject to a previously underappreciated number of lysine modifications. In this review, we will summarize the known lysine modifications of several key proteins involved in TLS; PCNA and Y-family polymerases η, ι, κ and Rev1 and we will discuss the potential regulatory effects of such modification in controlling TLS in vivo.
Collapse
Affiliation(s)
- Justyna McIntyre
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, ul. Pawinskiego 5a, 02-106 Warsaw, Poland.
| | - Roger Woodgate
- Laboratory of Genomic Integrity, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-3371, USA
| |
Collapse
|
56
|
Obrist F, Manic G, Kroemer G, Vitale I, Galluzzi L. Trial Watch: Proteasomal inhibitors for anticancer therapy. Mol Cell Oncol 2015; 2:e974463. [PMID: 27308423 PMCID: PMC4904962 DOI: 10.4161/23723556.2014.974463] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2014] [Revised: 09/15/2014] [Accepted: 09/17/2014] [Indexed: 01/12/2023]
Abstract
The so-called "ubiquitin-proteasome system" (UPS) is a multicomponent molecular apparatus that catalyzes the covalent attachment of several copies of the small protein ubiquitin to other proteins that are generally (but not always) destined to proteasomal degradation. This enzymatic cascade is crucial for the maintenance of intracellular protein homeostasis (both in physiological conditions and in the course of adaptive stress responses), and regulates a wide array of signaling pathways. In line with this notion, defects in the UPS have been associated with aging as well as with several pathological conditions including cardiac, neurodegenerative, and neoplastic disorders. As transformed cells often experience a constant state of stress (as a result of the hyperactivation of oncogenic signaling pathways and/or adverse microenvironmental conditions), their survival and proliferation are highly dependent on the integrity of the UPS. This rationale has driven an intense wave of preclinical and clinical investigation culminating in 2003 with the approval of the proteasomal inhibitor bortezomib by the US Food and Drug Administration for use in multiple myeloma patients. Another proteasomal inhibitor, carfilzomib, is now licensed by international regulatory agencies for use in multiple myeloma patients, and the approved indications for bortezomib have been extended to mantle cell lymphoma. This said, the clinical activity of bortezomib and carfilzomib is often limited by off-target effects, innate/acquired resistance, and the absence of validated predictive biomarkers. Moreover, the antineoplastic activity of proteasome inhibitors against solid tumors is poor. In this Trial Watch we discuss the contribution of the UPS to oncogenesis and tumor progression and summarize the design and/or results of recent clinical studies evaluating the therapeutic profile of proteasome inhibitors in cancer patients.
Collapse
Affiliation(s)
- Florine Obrist
- Université Paris-Sud/Paris XI; Le Kremlin-Bicêtre, France
- INSERM, U1138; Paris, France
- Equipe 11 labelisée par la Ligue Nationale contre le Cancer, Center de Recherche des Cordeliers; Paris, France
- Gustave Roussy Cancer Campus; Villejuif, France
| | | | - Guido Kroemer
- INSERM, U1138; Paris, France
- Equipe 11 labelisée par la Ligue Nationale contre le Cancer, Center de Recherche des Cordeliers; Paris, France
- Université Paris Descartes/Paris V; Sorbonne Paris Cité; Paris, France
- Pôle de Biologie, Hôpital Européen Georges Pompidou; Paris, France
- Metabolomics and Cell Biology Platforms; Gustave Roussy Cancer Campus; Villejuif, France
| | - Ilio Vitale
- Regina Elena National Cancer Institute; Rome, Italy
- Department of Biology, University of Rome “Tor Vergata”
| | - Lorenzo Galluzzi
- INSERM, U1138; Paris, France
- Equipe 11 labelisée par la Ligue Nationale contre le Cancer, Center de Recherche des Cordeliers; Paris, France
- Gustave Roussy Cancer Campus; Villejuif, France
- Université Paris Descartes/Paris V; Sorbonne Paris Cité; Paris, France
| |
Collapse
|
57
|
Ubiquitination of Dopamine Receptor Studied by Sequential Double Immunoprecipitation. NEUROMETHODS 2015. [DOI: 10.1007/978-1-4939-2196-6_8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
58
|
Bulatov E, Martin EM, Chatterjee S, Knebel A, Shimamura S, Konijnenberg A, Johnson C, Zinn N, Grandi P, Sobott F, Ciulli A. Biophysical studies on interactions and assembly of full-size E3 ubiquitin ligase: suppressor of cytokine signaling 2 (SOCS2)-elongin BC-cullin 5-ring box protein 2 (RBX2). J Biol Chem 2014; 290:4178-91. [PMID: 25505247 PMCID: PMC4326827 DOI: 10.1074/jbc.m114.616664] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The multisubunit cullin RING E3 ubiquitin ligases (CRLs) target post-translationally modified substrates for ubiquitination and proteasomal degradation. The suppressors of cytokine signaling (SOCS) proteins play important roles in inflammatory processes, diabetes, and cancer and therefore represent attractive targets for therapeutic intervention. The SOCS proteins, among their other functions, serve as substrate receptors of CRL5 complexes. A member of the CRL family, SOCS2-EloBC-Cul5-Rbx2 (CRL5(SOCS2)), binds phosphorylated growth hormone receptor as its main substrate. Here, we demonstrate that the components of CRL5(SOCS2) can be specifically pulled from K562 human cell lysates using beads decorated with phosphorylated growth hormone receptor peptides. Subsequently, SOCS2-EloBC and full-length Cul5-Rbx2, recombinantly expressed in Escherichia coli and in Sf21 insect cells, respectively, were used to reconstitute neddylated and unneddylated CRL5(SOCS2) complexes in vitro. Finally, diverse biophysical methods were employed to study the assembly and interactions within the complexes. Unlike other E3 ligases, CRL5(SOCS2) was found to exist in a monomeric state as confirmed by size exclusion chromatography with inline multiangle static light scattering and native MS. Affinities of the protein-protein interactions within the multisubunit complex were measured by isothermal titration calorimetry. A structural model for full-size neddylated and unneddylated CRL5(SOCS2) complexes is supported by traveling wave ion mobility mass spectrometry data.
Collapse
Affiliation(s)
- Emil Bulatov
- From the Division of Biological Chemistry and Drug Discovery, College of Life Sciences, and the Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom
| | - Esther M Martin
- the Department of Chemistry, University of Antwerp, 2020 Antwerp, Belgium, and
| | - Sneha Chatterjee
- the Department of Chemistry, University of Antwerp, 2020 Antwerp, Belgium, and
| | - Axel Knebel
- the Medical Research Council Phosphorylation and Ubiquitylation Unit, College of Life Sciences, Sir James Black Center, University of Dundee, Dundee DD1 5EH, Scotland, United Kingdom
| | | | - Albert Konijnenberg
- the Department of Chemistry, University of Antwerp, 2020 Antwerp, Belgium, and
| | - Clare Johnson
- the Medical Research Council Phosphorylation and Ubiquitylation Unit, College of Life Sciences, Sir James Black Center, University of Dundee, Dundee DD1 5EH, Scotland, United Kingdom
| | - Nico Zinn
- Cellzome GmbH, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Paola Grandi
- Cellzome GmbH, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Frank Sobott
- the Department of Chemistry, University of Antwerp, 2020 Antwerp, Belgium, and
| | - Alessio Ciulli
- From the Division of Biological Chemistry and Drug Discovery, College of Life Sciences, and the Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom,
| |
Collapse
|
59
|
Investigation of genetic variants in ubiquitin enzyme genes involved in the modulation of neurodevelopmental processes: a role in schizophrenia susceptibility? Genet Res (Camb) 2014; 96:e15. [PMID: 25578144 DOI: 10.1017/s0016672314000184] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Despite extensive research during the last few decades, the etiology of schizophrenia remains unclear. Evidence of both genetic and environmental influences in the developmental profile of schizophrenia has grown, and due to the complexity of this disorder, a polygenic aspect has been associated with this neuropsychiatric pathology. Unfortunately, no diagnostic strategies based on biological measurement or genetic testing is currently available for schizophrenia. Gene-expression profiling and recent protein studies have shown a decrease in the expression of ubiquitin pathway proteins in the prefrontal cortex of schizophrenia patients. We have examined single nucleotide polymorphisms (or SNPs) within three genes from the ubiquitin protein system: the ubiquitin conjugating enzyme E2D1 (UBE2D1) gene, the E3 SUMO-protein ligase protein inhibitor of activated STAT 2 (PIAS2) gene, and the E3 ubiquitin ligase F-box and leucine-rich repeat protein 21 (FBXL21) gene, in a Caucasian case-control population for schizophrenia. After Bonferroni correction for multiple testing was applied, no significant associations were reported for any of the tested SNPs. Additional genetic analyses will be necessary to fully explore the role of these three genes in schizophrenia. Regarding the rising interest in ubiquitin-related proteins as a therapeutic target in other pathologies such as cancer, further research into the role of ubiquitin pathways in schizophrenia seems topical and timely.
Collapse
|
60
|
Mlynarczuk-Bialy I, Doeppner TR, Golab J, Nowis D, Wilczynski GM, Parobczak K, Wigand ME, Hajdamowicz M, Biały LP, Aniolek O, Henklein P, Bähr M, Schmidt B, Kuckelkorn U, Kloetzel PM. Biodistribution and Efficacy Studies of the Proteasome Inhibitor BSc2118 in a Mouse Melanoma Model. Transl Oncol 2014; 7:570-9. [PMID: 25389452 PMCID: PMC4225687 DOI: 10.1016/j.tranon.2014.07.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Revised: 07/13/2014] [Accepted: 07/18/2014] [Indexed: 01/04/2023] Open
Abstract
Inhibition of the proteasome offers many therapeutic possibilities in inflammation as well as in neoplastic diseases. However, clinical use of proteasome inhibitors is limited by the development of resistance or severe side effects. In our study we characterized the anti-tumor properties of the novel proteasome inhibitor BSc2118. The sensitivity of tumor lines to BSc2118 was analyzed in comparison to bortezomib using crystal violet staining in order to assess cell viability. The In Vivo distribution of BSc2118 in mouse tissues was tracked by a fluorescent-modified form of BSc2118 (BSc2118-FL) and visualized by confocal microscopy. Inhibition of the 20S proteasome was monitored both in cultured cell lines and in mice, respectively. Finally, safety and efficacy of BSc2118 was evaluated in a mouse melanoma model. BSc2118 inhibits proliferation of different tumor cell lines with a similar potency as compared with bortezomib. Systemic administration of BSc2118 in mice is well tolerated, even when given in a dose of 60 mg/kg body weight. After systemic injection of BSc2118 or bortezomib similar proteasome inhibition patterns are observed within the murine organs. Detection of BSc2118-FL revealed correlation of distribution pattern of BSc2118 with inhibition of proteasomal activity in cells or mouse tissues. Finally, administration of BSc2118 in a mouse melanoma model shows significant local anti-tumor effects. Concluding, BSc2118 represents a novel low-toxic agent that might be alternatively used for known proteasome inhibitors in anti-cancer treatment.
Collapse
Affiliation(s)
| | | | - Jakub Golab
- Department of Immunology, Warsaw Medical University, Warsaw, Poland
| | - Dominika Nowis
- Department of Immunology, Warsaw Medical University, Warsaw, Poland
| | | | - Kamil Parobczak
- Nencki Institute of Experimental Biology, Polish Academy of Science, Warsaw, Poland
| | - Moritz E Wigand
- Institute of Biochemistry, Charité - Universitätsmedizin, Berlin, Germany
| | | | - Lukasz P Biały
- Department of Histology and Embryology, Warsaw Medical University, Warsaw, Poland
| | - Olga Aniolek
- Warsaw University of Life Sciences Faculty of Veterinary Medicine Department of Large Animal Diseases with the Clinic Division of Large Animal Internal Diseases, Warsaw, Poland
| | - Petra Henklein
- Institute of Biochemistry, Charité - Universitätsmedizin, Berlin, Germany
| | - Mathias Bähr
- Department of Neurology, University of Goettingen, Goettingen, Germany
| | - Boris Schmidt
- Clemens Schapf Institute for Organic Chemistry and Biochemistry, TU Darmstadt, Darmstadt, Germany
| | - Ulrike Kuckelkorn
- Institute of Biochemistry, Charité - Universitätsmedizin, Berlin, Germany
| | - Peter-M Kloetzel
- Institute of Biochemistry, Charité - Universitätsmedizin, Berlin, Germany
| |
Collapse
|
61
|
Structure of the human Cereblon–DDB1–lenalidomide complex reveals basis for responsiveness to thalidomide analogs. Nat Struct Mol Biol 2014; 21:803-9. [DOI: 10.1038/nsmb.2874] [Citation(s) in RCA: 301] [Impact Index Per Article: 30.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 07/16/2014] [Indexed: 12/17/2022]
|
62
|
Charbonneau ME, Gonzalez-Hernandez MJ, Showalter HD, Donato NJ, Wobus CE, O’Riordan MXD. Small molecule deubiquitinase inhibitors promote macrophage anti-infective capacity. PLoS One 2014; 9:e104096. [PMID: 25093325 PMCID: PMC4122495 DOI: 10.1371/journal.pone.0104096] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 07/07/2014] [Indexed: 12/18/2022] Open
Abstract
The global spread of anti-microbial resistance requires urgent attention, and diverse alternative strategies have been suggested to address this public health concern. Host-directed immunomodulatory therapies represent one approach that could reduce selection for resistant bacterial strains. Recently, the small molecule deubiquitinase inhibitor WP1130 was reported as a potential anti-infective drug against important human food-borne pathogens, notably Listeria monocytogenes and noroviruses. Utilization of WP1130 itself is limited due to poor solubility, but given the potential of this new compound, we initiated an iterative rational design approach to synthesize new derivatives with increased solubility that retained anti-infective activity. Here, we test a small library of novel synthetic molecules based on the structure of the parent compound, WP1130, for anti-infective activity in vitro. Our studies identify a promising candidate, compound 9, which reduced intracellular growth of L. monocytogenes at concentrations that caused minimal cellular toxicity. Compound 9 itself had no bactericidal activity and only modestly slowed Listeria growth rate in liquid broth culture, suggesting that this drug acts as an anti-infective compound by modulating host-cell function. Moreover, this new compound also showed anti-infective activity against murine norovirus (MNV-1) and human norovirus, using the Norwalk virus replicon system. This small molecule inhibitor may provide a chemical platform for further development of therapeutic deubiquitinase inhibitors with broad-spectrum anti-infective activity.
Collapse
Affiliation(s)
- Marie-Eve Charbonneau
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Marta J. Gonzalez-Hernandez
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Hollis D. Showalter
- Vahlteich Medicinal Chemistry Core, Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Nicholas J. Donato
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Christiane E. Wobus
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Mary X. D. O’Riordan
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan, United States of America
- * E-mail:
| |
Collapse
|
63
|
Uversky VN, Davé V, Iakoucheva LM, Malaney P, Metallo SJ, Pathak RR, Joerger AC. Pathological unfoldomics of uncontrolled chaos: intrinsically disordered proteins and human diseases. Chem Rev 2014; 114:6844-79. [PMID: 24830552 PMCID: PMC4100540 DOI: 10.1021/cr400713r] [Citation(s) in RCA: 192] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Vladimir N. Uversky
- Department of Molecular Medicine and USF Health Byrd Alzheimer’s Research Institute University of South Florida, Tampa, Florida 33612, United States
- Institute for Biological Instrumentation, Russian Academy of Sciences, 142290 Pushchino, Moscow Region, Russia
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah 22254, Saudi Arabia
| | - Vrushank Davé
- Department of Pathology and Cell Biology , Morsani College of Medicine, University of South Florida, Tampa, Florida 33612, United States
- Department of Molecular Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida 33612, United States
| | - Lilia M. Iakoucheva
- Department of Psychiatry, University of California San Diego, La Jolla, California 92093, United States
| | - Prerna Malaney
- Department of Pathology and Cell Biology , Morsani College of Medicine, University of South Florida, Tampa, Florida 33612, United States
| | - Steven J. Metallo
- Department of Chemistry, Georgetown University, Washington, District of Columbia 20057, United States
| | - Ravi Ramesh Pathak
- Department of Pathology and Cell Biology , Morsani College of Medicine, University of South Florida, Tampa, Florida 33612, United States
| | - Andreas C. Joerger
- Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| |
Collapse
|
64
|
Narváez-Pita X, Ortega-Zuniga C, Acevedo-Morantes CY, Pastrana B, Olivero-Verbel J, Maldonado-Rojas W, Ramírez-Vick JE, Meléndez E. Water soluble molybdenocene complexes: Synthesis, cytotoxic activity and binding studies to ubiquitin by fluorescence spectroscopy, circular dichroism and molecular modeling. J Inorg Biochem 2014; 132:77-91. [DOI: 10.1016/j.jinorgbio.2013.10.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Revised: 10/17/2013] [Accepted: 10/19/2013] [Indexed: 11/24/2022]
|
65
|
Yu L, Yang L, An W, Su X. Anticancer Bioactive Peptide-3 Inhibits Human Gastric Cancer Growth by Suppressing Gastric Cancer Stem Cells. J Cell Biochem 2014; 115:697-711. [DOI: 10.1002/jcb.24711] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Accepted: 11/05/2013] [Indexed: 11/07/2022]
Affiliation(s)
- Lan Yu
- Department of Cell Biology; Capital Medical University; No. 10 You An Men Wai Street Fengtai District Beijing 100069 China
| | - Ling Yang
- Clinical Medical Research Center of the Affiliated Hospital; Inner Mongolia Medical University; No. 1 Tongdao North Street Huimin District Hohhot 010050 China
| | - Wei An
- Department of Cell Biology; Capital Medical University; No. 10 You An Men Wai Street Fengtai District Beijing 100069 China
| | - Xiulan Su
- Department of Cell Biology; Capital Medical University; No. 10 You An Men Wai Street Fengtai District Beijing 100069 China
- Clinical Medical Research Center of the Affiliated Hospital; Inner Mongolia Medical University; No. 1 Tongdao North Street Huimin District Hohhot 010050 China
| |
Collapse
|
66
|
The ubiquitin/proteasome pathway in neoplasia. Mol Oncol 2013. [DOI: 10.1017/cbo9781139046947.041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
|
67
|
Zhang W, Sidhu SS. Development of inhibitors in the ubiquitination cascade. FEBS Lett 2013; 588:356-67. [PMID: 24239534 PMCID: PMC7094371 DOI: 10.1016/j.febslet.2013.11.003] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 11/04/2013] [Accepted: 11/04/2013] [Indexed: 12/16/2022]
Abstract
The ubiquitin proteasome system (UPS) is essential in regulating myriad aspects of protein functions. It is therefore a fundamentally important regulatory mechanism that impacts most if not all aspects of cellular processes. Indeed, malfunction of UPS components is implicated in human diseases such as neurodegenerative and immunological disorders and many cancers. The success of proteasome inhibitors in cancer therapy suggests that modulating enzymes in the ubiquitination cascade would be clinically important for therapeutic benefits. In this review, we summarize advances in developing inhibitors of a variety of UPS components. In particular, we highlight recent work done on the protein engineering of ubiquitin as modulators of the UPS, a novel approach that may shed light on innovative drug discovery in the future.
Collapse
Affiliation(s)
- Wei Zhang
- Donnelly Centre for Cellular and Biomolecular Research, Banting and Best Department of Medical Research, University of Toronto, 160 College Street, Toronto, Ontario M5S3E1, Canada; Department of Molecular Genetics, University of Toronto, 160 College Street, Toronto, Ontario M5S3E1, Canada
| | - Sachdev S Sidhu
- Donnelly Centre for Cellular and Biomolecular Research, Banting and Best Department of Medical Research, University of Toronto, 160 College Street, Toronto, Ontario M5S3E1, Canada; Department of Molecular Genetics, University of Toronto, 160 College Street, Toronto, Ontario M5S3E1, Canada.
| |
Collapse
|
68
|
Park JE, Ao L, Miller Z, Kim K, Wu Y, Jang ER, Lee EY, Kim KB, Lee W. PSMB9 codon 60 polymorphisms have no impact on the activity of the immunoproteasome catalytic subunit B1i expressed in multiple types of solid cancer. PLoS One 2013; 8:e73732. [PMID: 24040045 PMCID: PMC3767749 DOI: 10.1371/journal.pone.0073732] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Accepted: 07/20/2013] [Indexed: 11/18/2022] Open
Abstract
The proteasome is a key regulator of cellular protein homeostasis and is a clinically validated anticancer target. The immunoproteasome, a subtype of proteasome expressed mainly in hematopoietic cells, was initially recognized for its role in antigen presentation during the immune response. Recently, the immunoproteasome has been implicated in several disease conditions including cancer and autoimmune disorders, but many of the factors contributing to these pathological processes remain unknown. In particular, the codon 60 polymorphism of the PSMB9 gene encoding the β1i immunoproteasome catalytic subunit has been investigated in the context of a variety of diseases. Despite this, previous studies have so far reported inconsistent findings regarding the impact of this polymorphism on proteasome activity. Thus, we set out to investigate the impact of the PSMB9 codon 60 polymorphism on the expression and activity of the β1i immunoproteasome subunit in a panel of human cancer cell lines. The β1i-selective fluorogenic substrate Acetyl-Pro-Ala-Leu-7-amino-4-methylcoumarin was used to specifically measure β1i catalytic activity. Our results indicate that the codon 60 Arg/His polymorphism does not significantly alter the expression and activity of β1i among the cell lines tested. Additionally, we also examined the expression of β1i in clinical samples from colon and pancreatic cancer patients. Our immunohistochemical analyses showed that ∼70% of clinical colon cancer samples and ∼53% of pancreatic cancer samples have detectable β1i expression. Taken together, our results indicate that the β1i subunit of the immunoproteasome is frequently expressed in colon and pancreatic cancers but that the codon 60 genetic variants of β1i display similar catalytic activities and are unlikely to contribute to the significant inter-cell-line and inter-individual variabilities in the immunoproteasome activity.
Collapse
Affiliation(s)
- Ji Eun Park
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, Kentucky, United States of America
| | - Lin Ao
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, Kentucky, United States of America
| | - Zachary Miller
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, Kentucky, United States of America
| | - Kyungbo Kim
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, Kentucky, United States of America
| | - Ying Wu
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, Kentucky, United States of America
| | - Eun Ryoung Jang
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, Kentucky, United States of America
| | - Eun Young Lee
- Department of Pathology and Laboratory Medicine, College of Medicine, University of Kentucky, Lexington, Kentucky, United States of America
| | - Kyung Bo Kim
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, Kentucky, United States of America
| | - Wooin Lee
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, Kentucky, United States of America
- * E-mail:
| |
Collapse
|
69
|
Dou H, Buetow L, Sibbet GJ, Cameron K, Huang DT. Essentiality of a non-RING element in priming donor ubiquitin for catalysis by a monomeric E3. Nat Struct Mol Biol 2013; 20:982-986. [PMID: 23851457 PMCID: PMC4471106 DOI: 10.1038/nsmb.2621] [Citation(s) in RCA: 100] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Accepted: 05/21/2013] [Indexed: 12/20/2022]
Abstract
RING E3 ligases catalyze the transfer of ubiquitin (Ub) from E2 ubiquitin-conjugating enzyme thioesterified with Ub (E2~Ub) to substrate. For RING E3 dimers, the RING domain of one subunit and tail of the second cooperate to prime Ub, but how this is accomplished by monomeric RING E3s in the absence of a tail-like component is currently unknown. Here, we present a crystal structure of a monomeric RING E3, Tyr363-phosphorylated human CBL-B, bound to a stabilized Ub-linked E2, revealing a similar mechanism in activating E2~Ub. Both pTyr363 and the pTyr363-induced element interact directly with Ub's Ile36 surface, improving the catalytic efficiency of Ub transfer by ~200-fold. Hence, interactions outside the canonical RING domain are crucial for optimizing Ub transfer in both monomeric and dimeric RING E3s. We propose that an additional non-RING Ub-priming element may be a common RING E3 feature.
Collapse
Affiliation(s)
- Hao Dou
- The Beatson Institute for Cancer Research, Glasgow, United Kingdom
| | - Lori Buetow
- The Beatson Institute for Cancer Research, Glasgow, United Kingdom
| | - Gary J Sibbet
- The Beatson Institute for Cancer Research, Glasgow, United Kingdom
| | - Kenneth Cameron
- The Beatson Institute for Cancer Research, Glasgow, United Kingdom
| | - Danny T Huang
- The Beatson Institute for Cancer Research, Glasgow, United Kingdom
| |
Collapse
|
70
|
Li Y, Maciejewski MW, Martin J, Jin K, Zhang Y, Maupin-Furlow JA, Hao B. Crystal structure of the ubiquitin-like small archaeal modifier protein 2 from Haloferax volcanii. Protein Sci 2013; 22:1206-17. [PMID: 23821306 DOI: 10.1002/pro.2305] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 06/24/2013] [Accepted: 06/25/2013] [Indexed: 11/10/2022]
Abstract
The discovery of ubiquitin-like small archaeal modifier protein 2 (SAMP2) that forms covalent polymeric chains in Haloferax volcanii has generated tremendous interest in the function and regulation of this protein. At present, it remains unclear whether the Hfx. volcanii modifier protein SAMP1 has such polyubiquitinating-like activity. Although SAMP1 and SAMP2 use the same conjugation machinery to modify their target proteins, each can impart distinct functional consequences. To better understand the mechanism of SAMP2 conjugation, we have sought to characterize the biophysical and structural properties of the protein from Hfx. volcanii. SAMP2 is only partially structured under mesohalic solution conditions and adopts a well-folded compact conformation in the presence of 2.5M of NaCl. Its 2.3-Å-resolution crystal structure reveals a characteristic α/β central core domain and a unique β-hinge motif. This motif anchors an unusual C-terminal extension comprising the diglycine tail as well as two lysine residues that can potentially serve to interlink SAMP2 moieties. Mutational alternation of the structural malleability of this β-hinge motif essentially abolishes the conjugation activity of SAMP2 in vivo. In addition, NMR structural studies of the putative ubiquitin-like protein HVO_2177 from Hfx. volcanii show that like SAMP1, HVO_2177 forms a classic β-grasp fold in a salt-independent manner. These results provide insights into the structure-function relationship of sampylating proteins of fundamental importance in post-translational protein modification and environmental cues in Archaea.
Collapse
Affiliation(s)
- Yunfeng Li
- Department of Molecular, Microbial, and Structural Biology, University of Connecticut Health Center, Farmington, Connecticut, 06030
| | | | | | | | | | | | | |
Collapse
|
71
|
Mitra S, Traughber CA, Brannon MK, Gomez S, Capelluto DGS. Ubiquitin interacts with the Tollip C2 and CUE domains and inhibits binding of Tollip to phosphoinositides. J Biol Chem 2013; 288:25780-25791. [PMID: 23880770 DOI: 10.1074/jbc.m113.484170] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A large number of cellular signaling processes are directed through internalization, via endocytosis, of polyubiquitinated cargo proteins. Tollip is an adaptor protein that facilitates endosomal cargo sorting for lysosomal degradation. Tollip preferentially binds phosphatidylinositol 3-phosphate (PtdIns(3)P) via its C2 domain, an association that may be required for endosomal membrane targeting. Here, we show that Tollip binds ubiquitin through its C2 and CUE domains and that its association with the C2 domain inhibits PtdIns(3)P binding. NMR analysis demonstrates that the C2 and CUE domains bind to overlapping sites on ubiquitin, suggesting that two ubiquitin molecules associate with Tollip simultaneously. Hydrodynamic studies reveal that ubiquitin forms heterodimers with the CUE domain, indicating that the association disrupts the dimeric state of the CUE domain. We propose that, in the absence of polyubiquitinated cargo, the dual binding of ubiquitin partitions Tollip into membrane-bound and membrane-free states, a function that contributes to the engagement of Tollip in both membrane trafficking and cytosolic pathways.
Collapse
Affiliation(s)
- Sharmistha Mitra
- From the Department of Biological Sciences, Protein Signaling Domains Laboratory, Virginia Tech, Blacksburg, Virginia 24061
| | - C Alicia Traughber
- From the Department of Biological Sciences, Protein Signaling Domains Laboratory, Virginia Tech, Blacksburg, Virginia 24061
| | - Mary K Brannon
- From the Department of Biological Sciences, Protein Signaling Domains Laboratory, Virginia Tech, Blacksburg, Virginia 24061
| | - Stephanie Gomez
- From the Department of Biological Sciences, Protein Signaling Domains Laboratory, Virginia Tech, Blacksburg, Virginia 24061
| | - Daniel G S Capelluto
- From the Department of Biological Sciences, Protein Signaling Domains Laboratory, Virginia Tech, Blacksburg, Virginia 24061.
| |
Collapse
|
72
|
Verma S, Singh A, Mishra A. Molecular dynamics investigation on the poor sensitivity of A171T mutant NEDD8-activating enzyme (NAE) for MLN4924. J Biomol Struct Dyn 2013; 32:1064-73. [PMID: 23782099 DOI: 10.1080/07391102.2013.804436] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
MLN4924 is an adenosine sulfamate analog that generates the inhibitory NEDD8-MLN4924 covalent complex. A single nucleotide transition that changes alanine 171 to threonine (A171T) of the NAE subunit UBA3 reduces the enzyme's sensitivity for MLN4924. Our molecular dynamics simulation study revealed that A171T transition brought remarkable conformational changes in enzyme structure (open ATP binding pocket), which reduced the interaction between MLN4924 and ATP binding pocket while wild form completely covered the MLN4924. A total difference of -49.75 kJ/mol was noticed in interaction energy (electrostatic and van der Waals) during simulation between mutant and wild form with MLN4924. Superimposition of final 20 ns mutant structure with reference structure showed significant change in native binding position as compared to wild form. Results were found in coherence with the recently reported in vitro studies which states that A171T transition leads to change in ATP binding pocket structure.
Collapse
Affiliation(s)
- Sharad Verma
- a School of Biochemical Engineering, Indian Institute of Technology, Banaras Hindu University , Varanasi 221005 , India
| | | | | |
Collapse
|
73
|
Lee CS, Ho DV, Chan JY. Nuclear factor-erythroid 2-related factor 1 regulates expression of proteasome genes in hepatocytes and protects against endoplasmic reticulum stress and steatosis in mice. FEBS J 2013; 280:3609-20. [PMID: 23702335 DOI: 10.1111/febs.12350] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Revised: 05/14/2013] [Accepted: 05/20/2013] [Indexed: 12/22/2022]
Abstract
The ubiquitin-proteasome system is important in maintaining protein homeostasis. NFE2-related factor 1 (Nrf1), a transcription factor in the cap 'n' collar basic-leucine zipper family, regulates expression of cytoprotective genes. It was previously shown that liver-specific knockout of Nrf1 (Nrf1LKO) leads to hepatic cell death, steatohepatitis and cancer. However, the mechanisms underlying these pathologies are not clear. Here, we report that Nrf1 is critical for proteasome gene expression in the liver. Liver-specific knockout of Nrf1 results in impaired basal and induced expression of proteasome genes, and diminished proteasome activity in hepatocytes. In addition, our findings demonstrated that endoplasmic reticulum stress signaling pathway was also activated in Nrf1LKO livers. Inhibition of proteasome activity leads to endoplasmic reticulum stress in Nrf1-deficient hepatocytes, prompting the development of steatosis in the liver. Our results indicate that Nrf1 plays an integral role in the maintenance of proteasome function in hepatocytes and in the prevention of liver steatosis development. Moreover, these results highlight an association between proteasome dysfunction, endoplasmic reticulum stress and steatosis.
Collapse
Affiliation(s)
- Candy S Lee
- Department of Laboratory Medicine and Pathology, University of California Irvine, Irvine, CA 92697, USA
| | | | | |
Collapse
|
74
|
Abstract
The ubiquitin-proteasome system (UPS) and associated signaling pathways are regarded today as an exciting area of development for novel therapeutics. However, two decades ago, following the discovery and elucidation of ubiquitin and the 26S proteasome as key mediators of protein turnover, the concept of inhibiting the UPS was not even considered a feasible therapeutic approach due to the assumption that inhibition of this pathway would have widespread deleterious effects. Subsequent clinical developments with the first-in-class proteasome inhibitor bortezomib have radically overturned that view, with the proteasome now recognized as a validated target and proteasome inhibition demonstrated to be a highly successful treatment for a number of hematologic malignancies. Here we provide a historic perspective on the emergence of proteasome inhibition, sharing some of the lessons learned along the way. We describe the development of bortezomib and the elucidation of the effects of its novel mechanism of action, and place the cutting-edge work described elsewhere in this issue in the context of these historic developments.
Collapse
Affiliation(s)
- Dixie-Lee Esseltine
- Oncology Clinical Research, Millennium Pharmaceuticals, Inc, Cambridge, MA 02139, USA.
| | | |
Collapse
|
75
|
Broad-spectrum antimalarial activity of peptido sulfonyl fluorides, a new class of proteasome inhibitors. Antimicrob Agents Chemother 2013; 57:3576-84. [PMID: 23689711 DOI: 10.1128/aac.00742-12] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Despite declining numbers of cases and deaths, malaria remains a major public health problem in many parts of the world. Today, case management relies heavily on a single class of antimalarial compounds: artemisinins. Hence, development of resistance against artemisinins may destroy current malaria control strategies. Beyond malaria control are elimination and eradication programs that will require drugs with good activity against acute infection but also with preventive and transmission-blocking properties. Consequently, new antimalarials are needed not only to ensure malaria control but also for elimination and eradication efforts. In this study, we introduce peptido sulfonyl fluorides (PSF) as a new class of compounds with antiplasmodial activity. We show that PSF target the plasmodial proteasome and act on all asexual stages of the intraerythrocytic cycle and on gametocytes. PSF showed activities at concentrations as low as 20 nM against multidrug-resistant and chloroquine-sensitive Plasmodium falciparum laboratory strains and clinical isolates from Gabon. Structural requirements for activity were identified, and cytotoxicity in human HeLa or HEK 293 cells was low. The lead PSF PW28 suppressed growth of Plasmodium berghei in vivo but showed signs of toxicity in mice. Considering their modular structure and broad spectrum of activity against different stages of the plasmodial life cycle, proteasome inhibitors based on PSF have a great potential for further development as preclinical candidate compounds with improved species-specific activity and less toxicity.
Collapse
|
76
|
Kwon DY, Dimitriadi M, Terzic B, Cable C, Hart AC, Chitnis A, Fischbeck KH, Burnett BG. The E3 ubiquitin ligase mind bomb 1 ubiquitinates and promotes the degradation of survival of motor neuron protein. Mol Biol Cell 2013; 24:1863-71. [PMID: 23615451 PMCID: PMC3681692 DOI: 10.1091/mbc.e13-01-0042] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Spinal muscular atrophy is caused by deficiency of the survival motor neuron (SMN) protein. We show that the E3 ubiquitin ligase, mind bomb 1 (Mib1), ubiquitinates and targets SMN for degradation. Reducing Mib1 increases SMN levels, and decreasing the Caenorhabditis elegans orthologue of Mib1 mitigates a neuromuscular defect characteristic of SMN deficiency. Spinal muscular atrophy is an inherited motor neuron disease that results from a deficiency of the survival of motor neuron (SMN) protein. SMN is ubiquitinated and degraded through the ubiquitin proteasome system (UPS). We have previously shown that proteasome inhibition increases SMN protein levels, improves motor function, and reduces spinal cord, muscle, and neuromuscular junction pathology of spinal muscular atrophy (SMA) mice. Specific targets in the UPS may be more efficacious and less toxic. In this study, we show that the E3 ubiquitin ligase, mind bomb 1 (Mib1), interacts with and ubiquitinates SMN and facilitates its degradation. Knocking down Mib1 levels increases SMN protein levels in cultured cells. Also, knocking down the Mib1 orthologue improves neuromuscular function in Caenorhabditis elegans deficient in SMN. These findings demonstrate that Mib1 ubiquitinates and catalyzes the degradation of SMN, and thus represents a novel therapeutic target for SMA.
Collapse
Affiliation(s)
- Deborah Y Kwon
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | | | | | | | | | | | | | | |
Collapse
|
77
|
Bugliani M, Liechti R, Cheon H, Suleiman M, Marselli L, Kirkpatrick C, Filipponi F, Boggi U, Xenarios I, Syed F, Ladriere L, Wollheim C, Lee MS, Marchetti P. Microarray analysis of isolated human islet transcriptome in type 2 diabetes and the role of the ubiquitin-proteasome system in pancreatic beta cell dysfunction. Mol Cell Endocrinol 2013; 367:1-10. [PMID: 23246353 DOI: 10.1016/j.mce.2012.12.001] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2011] [Revised: 12/04/2012] [Accepted: 12/04/2012] [Indexed: 12/14/2022]
Abstract
To shed light on islet cell molecular phenotype in human type 2 diabetes (T2D), we studied the transcriptome of non-diabetic (ND) and T2D islets to then focus on the ubiquitin-proteasome system (UPS), the major protein degradation pathway. We assessed gene expression, amount of ubiquitinated proteins, proteasome activity, and the effects of proteasome inhibition and prolonged exposure to palmitate. Microarray analysis identified more than one thousand genes differently expressed in T2D islets, involved in many structures and functions, with consistent alterations of the UPS. Quantitative RT-PCR demonstrated downregulation of selected UPS genes in T2D islets and beta cell fractions, with greater ubiquitin accumulation and reduced proteasome activity. Chemically induced reduction of proteasome activity was associated with lower glucose-stimulated insulin secretion, which was partly reproduced by palmitate exposure. These results show the presence of many changes in islet transcriptome in T2D islets and underline the importance of the association between UPS alterations and beta cell dysfunction in human T2D.
Collapse
Affiliation(s)
- Marco Bugliani
- Department of Clinical and Experimental Medicine, Islet Cell Laboratory, University of Pisa, Pisa 56124, Italy
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
78
|
Ubiquitin-independent proteasomal degradation of tumor suppressors by human cytomegalovirus pp71 requires the 19S regulatory particle. J Virol 2013; 87:4665-71. [PMID: 23408605 DOI: 10.1128/jvi.03301-12] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Proteasomes generally degrade substrates tagged with polyubiquitin chains. In rare cases, however, proteasomes can degrade proteins without prior ubiquitination. For example, the human cytomegalovirus (HCMV) pp71 protein induces the proteasome-dependent, ubiquitin-independent degradation of the retinoblastoma (Rb) and Daxx proteins. These transcriptional corepressors and tumor suppressors inhibit the expression of cellular or viral genes that are required for efficient viral replication. Proteasomes are composed of a 20S catalytic core with or without one or two activator complexes, of which there are four different types. Here, we show that only one of these activators, the 19S regulatory particle that normally participates in ubiquitin-dependent protein degradation, is required for pp71-mediated degradation of Rb and Daxx. We report the unique use of a well-established route of substrate delivery to the proteasome by a viral protein to promote infection.
Collapse
|
79
|
Hutchins AP, Liu S, Diez D, Miranda-Saavedra D. The repertoires of ubiquitinating and deubiquitinating enzymes in eukaryotic genomes. Mol Biol Evol 2013; 30:1172-87. [PMID: 23393154 PMCID: PMC3670738 DOI: 10.1093/molbev/mst022] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Reversible protein ubiquitination regulates virtually all known cellular activities. Here, we present a quantitatively evaluated and broadly applicable method to predict eukaryotic ubiquitinating enzymes (UBE) and deubiquitinating enzymes (DUB) and its application to 50 distinct genomes belonging to four of the five major phylogenetic supergroups of eukaryotes: unikonts (including metazoans, fungi, choanozoa, and amoebozoa), excavates, chromalveolates, and plants. Our method relies on a collection of profile hidden Markov models, and we demonstrate its superior performance (coverage and classification accuracy >99%) by identifying approximately 25% and approximately 35% additional UBE and DUB genes in yeast and human, which had not been reported before. In yeast, we predict 85 UBE and 24 DUB genes, for 814 UBE and 107 DUB genes in the human genome. Most UBE and DUB families are present in all eukaryotic lineages, with plants and animals harboring massively enlarged repertoires of ubiquitin ligases. Unicellular organisms, on the other hand, typically harbor less than 300 UBEs and less than 40 DUBs per genome. Ninety-one UBE/DUB genes are orthologous across all four eukaryotic supergroups, and these likely represent a primordial core of enzymes of the ubiquitination system probably dating back to the first eukaryotes approximately 2 billion years ago. Our genome-wide predictions are available through the Database of Ubiquitinating and Deubiquitinating Enzymes (www.DUDE-db.org), where users can also perform advanced sequence and phylogenetic analyses and submit their own predictions.
Collapse
Affiliation(s)
- Andrew Paul Hutchins
- Bioinformatics and Genomics Laboratory, World Premier International Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | | | | | | |
Collapse
|
80
|
Doeppner TR, Mlynarczuk-Bialy I, Kuckelkorn U, Kaltwasser B, Herz J, Hasan MR, Hermann DM, Bähr M. The novel proteasome inhibitor BSc2118 protects against cerebral ischaemia through HIF1A accumulation and enhanced angioneurogenesis. ACTA ACUST UNITED AC 2013; 135:3282-97. [PMID: 23169919 DOI: 10.1093/brain/aws269] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Only a minority of stroke patients receive thrombolytic therapy. Therefore, new therapeutic strategies focusing on neuroprotection are under review, among which, inhibition of the proteasome is attractive, as it affects multiple cellular pathways. As proteasome inhibitors like bortezomib have severe side effects, we applied the novel proteasome inhibitor BSc2118, which is putatively better tolerated, and analysed its therapeutic potential in a mouse model of cerebral ischaemia. Stroke was induced in male C57BL/6 mice using the intraluminal middle cerebral artery occlusion model. BSc2118 was intrastriatally injected 12 h post-stroke in mice that had received normal saline or recombinant tissue-plasminogen activator injections during early reperfusion. Brain injury, behavioural tests, western blotting, MMP9 zymography and analysis of angioneurogenesis were performed for up to 3 months post-stroke. Single injections of BSc2118 induced long-term neuroprotection, reduced functional impairment, stabilized blood-brain barrier through decreased MMP9 activity and enhanced angioneurogenesis when given no later than 12 h post-stroke. On the contrary, recombinant tissue-plasminogen activator enhanced brain injury, which was reversed by BSc2118. Protein expression of the transcription factor HIF1A was significantly increased in saline-treated and recombinant tissue-plasminogen activator-treated mice after BSc2118 application. In contrast, knock-down of HIF1A using small interfering RNA constructs or application of the HIF1A inhibitor YC1 (now known as RNA-binding motif, single-stranded-interacting protein 1 (RBMS1)) reversed BSc2118-induced neuroprotection. Noteworthy, loss of neuroprotection after combined treatment with BSc2118 and YC1 in recombinant tissue-plasminogen activator-treated animals was in the same order as in saline-treated mice, i.e. reduction of recombinant tissue-plasminogen activator toxicity through BSc2118 did not solely depend on HIF1A. Thus, the proteasome inhibitor BSc2118 is a promising new candidate for stroke therapy, which may in addition alleviate recombinant tissue-plasminogen activator-induced brain toxicity.
Collapse
Affiliation(s)
- Thorsten R Doeppner
- Department of Neurology, University of Duisburg-Essen Medical School, Essen, Germany.
| | | | | | | | | | | | | | | |
Collapse
|
81
|
Abstract
Thioredoxin-interacting protein (Txnip) is a metabolic regulator, which modulates insulin sensitivity and likely plays a role in type 2 diabetes. We studied the regulation of Txnip in 3T3-L1 adipocytes. Cells were incubated under different conditions and Txnip was measured by immunoblotting. We confirmed that high glucose markedly increases Txnip expression by promoting transcription. Insulin decreases Txnip protein levels. Rapamycin under most conditions decreased Txnip, suggesting that mTOR complex-1 is involved. The acute effects of insulin are mainly posttranscriptional; insulin (100 nM) accelerates Txnip degradation more than tenfold. This effect is cell type specific. It works in adipocytes, preadipocytes and in L6 myotubes but not in HepG2 or in HEK 293 cells or in a pancreatic β-cell line. The ubiquitin/proteasome pathway is involved. Degradation of Txnip occurred within 15 min in the presence of 3 nM insulin and overnight with 0.6 nM insulin. Proteasomal Txnip degradation is not mediated by a cysteine protease or an anti-calpain enzyme. Okadaic acid (OKA), an inhibitor of phosphoprotein phosphatases (pp), markedly reduced Txnip protein and stimulated its further decrease by insulin. The latter occurred after incubation with 1 or 1000 nM OKA, suggesting that insulin enhances the phosphorylation of a pp2A substrate. Incubation with 0.1 μM Wortmannin, a PI3 kinase inhibitor, increased Txnip protein twofold and significantly inhibited its insulin-induced decrease. Thus, while OKA mimics the effect of insulin, Wortmannin opposes it. In summary, insulin stimulates Txnip degradation by a PI3 kinase-dependent mechanism, which activates the ubiquitin/proteasome pathway and likely serves to mitigate insulin resistance.
Collapse
Affiliation(s)
- Katherine A Robinson
- Division of Endocrinology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina, USA
| | | | | |
Collapse
|
82
|
Moffat JM, Mintern JD, Villadangos JA. Control of MHC II antigen presentation by ubiquitination. Curr Opin Immunol 2013. [DOI: 10.1016/j.coi.2012.10.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
|
83
|
Gong Y, Wang D, Dar JA, Singh P, Graham L, Liu W, Ai J, Xin Z, Guo Y, Wang Z. Nuclear export signal of androgen receptor (NESAR) regulation of androgen receptor level in human prostate cell lines via ubiquitination and proteasome-dependent degradation. Endocrinology 2012; 153:5716-25. [PMID: 23041672 PMCID: PMC3512072 DOI: 10.1210/en.2012-1841] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Androgen receptor (AR) plays a key role in prostate development and carcinogenesis. Increased expression and/or stability of AR is associated with sensitization of prostate cancer cells to low levels of androgens, leading to castration resistance. Hence, understanding the mechanisms regulating AR protein stability is clinically relevant and may lead to new approaches to prevent and/or treat prostate cancer. Using fluorescence microscopy, Western blot, and pulse chase assay, we showed that nuclear export signal (NES)(AR), a nuclear export signal in the ligand binding domain (LBD) of AR, can significantly enhance the degradation of fusion protein constructs in PC3 prostate cancer cells. The half-life of GFP-NES(AR) was less than 3 h, which was 10 times shorter than that of green fluorescent protein (GFP) control. Further analysis showed that NES(AR) can signal for polyubiquitination and that degradation of NES(AR)-containing fusion proteins can be blocked by proteasome inhibitor MG132. Ubiquitination of GFP-AR or GFP-LBD was suppressed in the presence of dihydrotestosterone, which is known to suppress NES(AR) while inducing nuclear localization signal 2 in AR or LBD, suggesting that the export activity of NES(AR) is required for NES(AR)-mediated polyubiquitination. Treatment with MG132 also induced aggresome formation of NES(AR)-containing fusion proteins in perinuclear regions of the transfected PC3 cells, indicating a role for NES(AR) in inducing unfolded protein responses. The above observations suggest that NES(AR) plays a key role in AR ubiquitination and proteasome-dependent degradation in prostate cancer cells.
Collapse
Affiliation(s)
- Yanqing Gong
- Department of Urology, Peking University First Hospital and Institute of Urology, Peking University, No. 8, Xishiku Street, Xicheng District, Beijing 100034, China.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
84
|
Papaleo E, Casiraghi N, Arrigoni A, Vanoni M, Coccetti P, De Gioia L. Loop 7 of E2 enzymes: an ancestral conserved functional motif involved in the E2-mediated steps of the ubiquitination cascade. PLoS One 2012; 7:e40786. [PMID: 22815819 PMCID: PMC3399832 DOI: 10.1371/journal.pone.0040786] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Accepted: 06/12/2012] [Indexed: 12/31/2022] Open
Abstract
The ubiquitin (Ub) system controls almost every aspect of eukaryotic cell biology. Protein ubiquitination depends on the sequential action of three classes of enzymes (E1, E2 and E3). E2 Ub-conjugating enzymes have a central role in the ubiquitination pathway, interacting with both E1 and E3, and influencing the ultimate fate of the substrates. Several E2s are characterized by an extended acidic insertion in loop 7 (L7), which if mutated is known to impair the proper E2-related functions. In the present contribution, we show that acidic loop is a conserved ancestral motif in E2s, relying on the presence of alternate hydrophobic and acidic residues. Moreover, the dynamic properties of a subset of family 3 E2s, as well as their binary and ternary complexes with Ub and the cognate E3, have been investigated. Here we provide a model of L7 role in the different steps of the ubiquitination cascade of family 3 E2s. The L7 hydrophobic residues turned out to be the main determinant for the stabilization of the E2 inactive conformations by a tight network of interactions in the catalytic cleft. Moreover, phosphorylation is known from previous studies to promote E2 competent conformations for Ub charging, inducing electrostatic repulsion and acting on the L7 acidic residues. Here we show that these active conformations are stabilized by a network of hydrophobic interactions between L7 and L4, the latter being a conserved interface for E3-recruitment in several E2s. In the successive steps, L7 conserved acidic residues also provide an interaction interface for both Ub and the Rbx1 RING subdomain of the cognate E3. Our data therefore suggest a crucial role for L7 of family 3 E2s in all the E2-mediated steps of the ubiquitination cascade. Its different functions are exploited thank to its conserved hydrophobic and acidic residues in a finely orchestrate mechanism.
Collapse
Affiliation(s)
- Elena Papaleo
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy.
| | | | | | | | | | | |
Collapse
|
85
|
Nawrocki ST, Griffin P, Kelly KR, Carew JS. MLN4924: a novel first-in-class inhibitor of NEDD8-activating enzyme for cancer therapy. Expert Opin Investig Drugs 2012; 21:1563-73. [PMID: 22799561 DOI: 10.1517/13543784.2012.707192] [Citation(s) in RCA: 128] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
INTRODUCTION The small ubiquitin-like molecule NEDD8 has been identified as an essential regulator of the activity of the cullin-RING E3 ubiquitin ligases (CRLs), which control the turnover of multiple proteins with fundamental roles in cancer biology. The aberrant function of the NEDD8 cascade within the context of malignancy makes it an attractive target for the development of novel anticancer agents. MLN4924 is a first-in-class inhibitor of the proximal regulator of the NEDD8 system (NEDD8-activating enzyme, NAE) that has entered Phase-I trials for cancer therapy and has established that significant therapeutic benefit can be achieved by antagonizing NEDD8-mediated protein degradation. AREAS COVERED This review provides a detailed overview of the NEDD8 system and discusses the mechanisms of action of MLN4924, a novel small molecule NAE inhibitor. Key findings from preclinical investigations of MLN4924 in a broad range of cancer models and preliminary findings from ongoing Phase-I clinical trials with MLN4924 are also discussed. EXPERT OPINION Targeting protein NEDDylation represents an exciting new anticancer strategy with demonstrable therapeutic benefit. Ongoing and future studies focused on dissecting the functional status/regulation of the NEDD8 system in individual tumor types will facilitate the design of novel approaches that yield optimal therapeutic benefit.
Collapse
Affiliation(s)
- Steffan T Nawrocki
- The University of Texas Health Science Center at San Antonio, Cancer Therapy and Research Center, MC8232, 7979 Wurzbach Rd, San Antonio, TX 78229, USA
| | | | | | | |
Collapse
|
86
|
Ao L, Wu Y, Kim D, Jang ER, Kim K, Lee DM, Kim KB, Lee W. Development of peptide-based reversing agents for p-glycoprotein-mediated resistance to carfilzomib. Mol Pharm 2012; 9:2197-205. [PMID: 22734651 DOI: 10.1021/mp300044b] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Carfilzomib is a novel class of peptidyl epoxyketone proteasome inhibitor and has demonstrated promising activity in multiple clinical trials to treat patients with multiple myeloma and other types of cancers. Here, we investigated molecular mechanisms underlying acquired resistance to carfilzomib and a potential strategy to restore cellular sensitivity to carfilzomib. H23 and DLD-1 cells (human lung and colon adenocarcinoma cell lines) with acquired resistance to carfilzomib displayed marked cross-resistance to YU-101, a closely related proteasome inhibitor, and paclitaxel, a known substrate of Pgp. However, carfilzomib-resistant cells remained sensitive to bortezomib, a clinically used dipeptide with boronic acid pharmacophore. In accordance with these observations, carfilzomib-resistant H23 and DLD-1 cells showed marked upregulation of P-glycoprotein (Pgp) as compared to their parental controls, and coincubation with verapamil, a Pgp inhibitor, led to an almost complete restoration of cellular sensitivity to carfilzomib. These results indicate that Pgp upregulation plays a major role in the development of carfilzomib resistance in these cell lines. In developing a potential strategy to overcome carfilzomib resistance, we as a proof of concept prepared a small library of peptide analogues derived from the peptide backbone of carfilzomib and screened these molecules for their activity to restore carfilzomib sensitivity when cotreated with carfilzomib. We found that compounds as small as dipeptides are sufficient in restoring carfilzomib sensitivity. Taken together, we found that Pgp upregulation plays a major role in the development of resistance to carfilzomib in lung and colon adenocarcinoma cell lines and that small peptide analogues lacking the pharmacophore can be used as agents to reverse acquired carfilzomib resistance. Our findings may provide important information in developing a potential strategy to overcome drug resistance.
Collapse
Affiliation(s)
- Lin Ao
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky , Lexington, Kentucky 40536, United States
| | | | | | | | | | | | | | | |
Collapse
|
87
|
Antiviral activity of a small molecule deubiquitinase inhibitor occurs via induction of the unfolded protein response. PLoS Pathog 2012; 8:e1002783. [PMID: 22792064 PMCID: PMC3390402 DOI: 10.1371/journal.ppat.1002783] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Accepted: 05/16/2012] [Indexed: 12/11/2022] Open
Abstract
Ubiquitin (Ub) is a vital regulatory component in various cellular processes, including cellular responses to viral infection. As obligate intracellular pathogens, viruses have the capacity to manipulate the ubiquitin (Ub) cycle to their advantage by encoding Ub-modifying proteins including deubiquitinases (DUBs). However, how cellular DUBs modulate specific viral infections, such as norovirus, is poorly understood. To examine the role of DUBs during norovirus infection, we used WP1130, a small molecule inhibitor of a subset of cellular DUBs. Replication of murine norovirus in murine macrophages and the human norovirus Norwalk virus in a replicon system were significantly inhibited by WP1130. Chemical proteomics identified the cellular DUB USP14 as a target of WP1130 in murine macrophages, and pharmacologic inhibition or siRNA-mediated knockdown of USP14 inhibited murine norovirus infection. USP14 is a proteasome-associated DUB that also binds to inositol-requiring enzyme 1 (IRE1), a critical mediator of the unfolded protein response (UPR). WP1130 treatment of murine macrophages did not alter proteasome activity but activated the X-box binding protein-1 (XBP-1) through an IRE1-dependent mechanism. In addition, WP1130 treatment or induction of the UPR also reduced infection of other RNA viruses including encephalomyocarditis virus, Sindbis virus, and La Crosse virus but not vesicular stomatitis virus. Pharmacologic inhibition of the IRE1 endonuclease activity partially rescued the antiviral effect of WP1130. Taken together, our studies support a model whereby induction of the UPR through cellular DUB inhibition blocks specific viral infections, and suggest that cellular DUBs and the UPR represent novel targets for future development of broad spectrum antiviral therapies. Deubiquitinases (DUBs) are enzymes, which are implicated in many cellular processes but their functions during virus infection are not well understood. We used WP1130, a small molecule inhibitor of a subset of DUBs, as a probe to unravel the functions of DUBs during norovirus infections. We identified USP14 as a cellular DUB target of WP1130 that is required for optimal norovirus infection. Furthermore, we demonstrated that chemical induction of the unfolded protein response can significantly inhibit viral progeny production of several RNA viruses, including noroviruses. These results suggest that chemical inhibition of cellular DUBs and/or modulation of the unfolded protein response could represent novel targets for therapy against a variety of viral pathogens.
Collapse
|
88
|
Deng S, Jing B, Xing T, Hou L, Yang Z. Overexpression of annexin A2 is associated with abnormal ubiquitination in breast cancer. GENOMICS PROTEOMICS & BIOINFORMATICS 2012; 10:153-7. [PMID: 22917188 PMCID: PMC5054490 DOI: 10.1016/j.gpb.2011.12.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Revised: 12/30/2011] [Accepted: 12/31/2011] [Indexed: 11/22/2022]
Abstract
Abnormal expression of annexin A2 contributes to metastasis and infiltration of cancer cells. To elucidate the cause of abnormal expression of annexin A2, Western blotting, immunoproteomics and immunohistochemical staining were performed to analyze differentially ubiquitinated proteins between fresh breast cancer tissue and its adjacent normal breast tissue from five female volunteers. We detected an ubiquitinated protein that was up-regulated in the cancer tissue, which was further identified as annexin A2 by mass spectrometry. These results suggest that abnormal ubiquitination and/or degradation of annexin A2 may lead to presence of annexin A2 at high level, which may further promote metastasis and infiltration of the breast cancer cells.
Collapse
Affiliation(s)
- Shishan Deng
- Department of Anatomy, North Sichuan Medical College, Nanchong 637007, China.
| | | | | | | | | |
Collapse
|
89
|
Jang ER, Lee NR, Han S, Wu Y, Sharma LK, Carmony KC, Marks J, Lee DM, Ban JO, Wehenkel M, Hong JT, Kim KB, Lee W. Revisiting the role of the immunoproteasome in the activation of the canonical NF-κB pathway. MOLECULAR BIOSYSTEMS 2012; 8:2295-302. [PMID: 22722901 DOI: 10.1039/c2mb25125f] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The discovery of NF-κB signaling pathways has greatly enhanced our understanding of inflammatory and immune responses. In the canonical NF-κB pathway, the proteasomal degradation of IκBα, an inhibitory protein of NF-κB, is widely accepted to be a key regulatory step. However, contradictory findings have been reported as to whether the immunoproteasome plays an obligatory role in the degradation of IκBα and activation of the canonical NF-κB pathway. Such results were obtained mainly using traditional gene deletion strategies. Here, we have revisited the involvement of the immunoproteasome in the canonical NF-κB pathway using small molecule inhibitors of the immunoproteasome, namely UK-101 and LKS01 targeting β1i and β5i, respectively. H23 and Panc-1 cancer cells were pretreated with UK-101, LKS01 or epoxomicin (a prototypic inhibitor targeting both the constitutive proteasome and immunoproteasome). We then examined whether these pretreatments lead to any defect in activating the canonical NF-κB pathway following TNFα exposure by monitoring the phosphorylation and degradation of IκBα, nuclear translocation of NF-κB proteins and DNA binding and transcriptional activity of NF-κB. Our results consistently indicated that there is no defect in activating the canonical NF-κB pathway following selective inhibition of the immunoproteasome catalytic subunits β1i, β5i or both using UK-101 and LKS01, in contrast to epoxomicin. In summary, our current results using chemical genetic approaches strongly support that the catalytic activity of the immunoproteasome subunits β1i and β5i is not required for canonical NF-κB activation in lung and pancreatic adenocarcinoma cell line models.
Collapse
Affiliation(s)
- Eun Ryoung Jang
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone, Lexington, Kentucky 40536-0596, USA
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
90
|
Arrigoni A, Grillo B, Vitriolo A, De Gioia L, Papaleo E. C-terminal acidic domain of ubiquitin-conjugating enzymes: A multi-functional conserved intrinsically disordered domain in family 3 of E2 enzymes. J Struct Biol 2012; 178:245-59. [DOI: 10.1016/j.jsb.2012.04.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2011] [Revised: 04/01/2012] [Accepted: 04/03/2012] [Indexed: 11/30/2022]
|
91
|
Xu L, Qu Z. Roles of protein ubiquitination and degradation kinetics in biological oscillations. PLoS One 2012; 7:e34616. [PMID: 22506034 PMCID: PMC3323547 DOI: 10.1371/journal.pone.0034616] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Accepted: 03/02/2012] [Indexed: 12/31/2022] Open
Abstract
Protein ubiquitination and degradation play important roles in many biological functions and are associated with many human diseases. It is well known that for biochemical oscillations to occur, proper degradation rates of the participating proteins are needed. In most mathematical models of biochemical reactions, linear degradation kinetics has been used. However, the degradation kinetics in real systems may be nonlinear, and how nonlinear degradation kinetics affects biological oscillations are not well understood. In this study, we first develop a biochemical reaction model of protein ubiquitination and degradation and calculate the degradation rate against the concentration of the free substrate. We show that the protein degradation kinetics mainly follows the Michaelis-Menten formulation with a time delay caused by ubiquitination and deubiquitination. We then study analytically how the Michaelis-Menten degradation kinetics affects the instabilities that lead to oscillations using three generic oscillation models: 1) a positive feedback mediated oscillator; 2) a positive-plus-negative feedback mediated oscillator; and 3) a negative feedback mediated oscillator. In all three cases, nonlinear degradation kinetics promotes oscillations, especially for the negative feedback mediated oscillator, resulting in much larger oscillation amplitudes and slower frequencies than those observed with linear kinetics. However, the time delay due to protein ubiquitination and deubiquitination generally suppresses oscillations, reducing the amplitude and increasing the frequency of the oscillations. These theoretical analyses provide mechanistic insights into the effects of specific proteins in the ubiquitination-proteasome system on biological oscillations.
Collapse
Affiliation(s)
- Lida Xu
- Department of Medicine (Cardiology), David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
- Department of Systems Science, Beijing Normal University, Beijing, People's Republic of China
| | - Zhilin Qu
- Department of Medicine (Cardiology), David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| |
Collapse
|
92
|
Woodsmith J, Jenn RC, Sanderson CM. Systematic analysis of dimeric E3-RING interactions reveals increased combinatorial complexity in human ubiquitination networks. Mol Cell Proteomics 2012; 11:M111.016162. [PMID: 22493164 PMCID: PMC3394952 DOI: 10.1074/mcp.m111.016162] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Ubiquitination controls the stability or function of many human proteins, thereby regulating a wide range of physiological processes. In most cases the combinatorial pattern of protein interactions that facilitate substrate recognition or modification remain unclear. Moreover, the efficiency of ubiquitination reactions can be altered by the formation of homo- and heterotypic E3-RING complexes. To establish the prevalence and nature of binary E3-RING/E3-RING interactions systematic yeast two-hybrid screens were performed to test 7269 potential interactions between 124 human E3-RING proteins. These studies identified 228 dimeric interactions between 100 E3-RINGs, of which 205 were novel. Complementary co-immunoprecipitation studies were performed to test predicted network interactions, showing a high correlation (64%) with primary yeast two-hybrid data. This data was integrated with known E3-RING interactions, tissue expression profiles and proteomic ubiquitination datasets to facilitate identification of subnetworks in which E3-RING dimerization events have the potential to alter network structure. These results reveal a widespread yet selective pattern of E3-RING dimerization events, which have the potential to confer further combinatorial complexity within human ubiquitination cascades.
Collapse
Affiliation(s)
- Jonathan Woodsmith
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, L69 3BX, UK
| | | | | |
Collapse
|
93
|
Toth JI, Yang L, Dahl R, Petroski MD. A gatekeeper residue for NEDD8-activating enzyme inhibition by MLN4924. Cell Rep 2012; 1:309-16. [PMID: 22832224 DOI: 10.1016/j.celrep.2012.02.006] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2011] [Revised: 02/04/2012] [Accepted: 02/15/2012] [Indexed: 10/28/2022] Open
Abstract
Inhibition of NEDD8-activating enzyme (NAE) has emerged as a highly promising approach to treat cancer through the adenosine sulfamate analog MLN4924. Here, we show that selective pressure results in HCT116 colorectal carcinoma cells with decreased MLN4924 sensitivity and identify a single-nucleotide transition that changes alanine 171 to threonine (A171T) of the NAE subunit UBA3. This reduces the enzyme's affinity for MLN4924 and ATP while increasing NEDD8 activation at physiological ATP concentrations. Expression of UBA3 A171T is sufficient to decrease MLN4924 sensitivity of naive HCT116 cells, indicating that it is a dominant suppressor of MLN4924-mediated cell death. Our data suggest that the on-target potency of MLN4924 selects for a point mutation in NAE that overcomes the molecule's inhibitory effects, allowing cancer cell survival.
Collapse
Affiliation(s)
- Julia I Toth
- Signal Transduction Program, Sanford-Burnham Medical Research Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | | | | | | |
Collapse
|
94
|
Abstract
A strict physiological balance between endogenous proangiogenic and antiangiogenic factors controls endothelial cell functions, such that endothelial cell growth is normally restrained. However, in pathologic angiogenesis, a shift occurs in the balance of regulators, favoring endothelial growth. Much of the control of angiogenic events is instigated through hypoxia-induced VEGF expression. The ubiquitin-proteasome system (UPS) plays a central role in fine-tuning the functions of core proangiogenic proteins, including VEGF, VEGFR-2, angiogenic signaling proteins (e.g., the PLCγ1 and PI3 kinase/AKT pathways), and other non-VEGF angiogenic pathways. The emerging mechanisms by which ubiquitin modification of angiogenic proteins control angiogenesis involve both proteolytic and nonproteolytic functions. Here, I review recent advances that link the UPS to regulation of angiogenesis and highlight the potential therapeutic value of the UPS in angiogenesis-associated diseases.
Collapse
Affiliation(s)
- Nader Rahimi
- Department of Pathology, Boston University Medical Campus, 670 Albany St., Room 510, Boston, MA 02118, USA.
| |
Collapse
|
95
|
Targeting the ubiquitin–proteasome pathway with inorganic compounds to fight cancer: a challenge for the future. Future Med Chem 2012; 4:525-43. [DOI: 10.4155/fmc.11.187] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Proteasomes are large multicatalytic complexes endowed with proteinase activity, located both in the cytosol and in the nucleus of eukaryotic cells. The ubiquitin–proteasome system is responsible for selective degradation of most intracellular proteins and therefore plays an essential regulatory role in many critical cellular processes. The proteasomal activity can also contribute to the pathological states of many diseases, including inflammation, neurodegeneration and cancer, through a disregulation in the level of regulatory proteins. These diseases may be targeted by modulating components of the ubiquitin–proteasome pathway, using small molecules as inhibitors. Bortezomib (Velcade®), used for the treatment of relapsed multiple myeloma, is the first and, up to now, the only proteasome inhibitor approved by the US FDA. Nowadays, the discovery that some metal-based complexes exert their antiproliferative action by affecting proteasomal activities provides the possibility of developing new opportunities in cancer therapy.
Collapse
|
96
|
Moran-Crusio K, Reavie LB, Aifantis I. Regulation of hematopoietic stem cell fate by the ubiquitin proteasome system. Trends Immunol 2012; 33:357-63. [PMID: 22349458 DOI: 10.1016/j.it.2012.01.009] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2011] [Revised: 11/30/2011] [Accepted: 01/12/2012] [Indexed: 01/10/2023]
Abstract
Hematopoietic stem cells (HSCs) residing in the bone marrow generate mature blood cells throughout the life of the organism. This is accomplished by careful regulation of HSC activity to balance quiescence, self-renewal and differentiation. Studies of the molecular mechanisms governing HSC maintenance have mostly focused on the role of signaling and transcriptional processes. However, it has recently been demonstrated that protein regulation via the ubiquitin proteasome system (UPS) is crucial for normal HSC function; the loss of which can lead to transformation and leukemogenesis. The effective use of a general and reversible inhibitor of the UPS, bortezomib, in treating mantle cell lymphoma and multiple myeloma has demonstrated that targeting the UPS has therapeutic potential. Thus, understanding the emerging field of how the UPS regulates HSC activity may lead to novel targets for therapy of leukemia.
Collapse
Affiliation(s)
- Kelly Moran-Crusio
- Department of Pathology and NYU Cancer Institute, NYU School of Medicine, New York, NY 10016, USA
| | | | | |
Collapse
|
97
|
Carmony KC, Lee DM, Wu Y, Lee NR, Wehenkel M, Lee J, Lei B, Zhan CG, Kim KB. A bright approach to the immunoproteasome: development of LMP2/β1i-specific imaging probes. Bioorg Med Chem 2012; 20:607-13. [PMID: 21741845 PMCID: PMC3193892 DOI: 10.1016/j.bmc.2011.06.039] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Revised: 05/31/2011] [Accepted: 06/14/2011] [Indexed: 01/01/2023]
Abstract
While the constitutive, 26S proteasome plays an important role in regulating many important cellular processes, a variant form known as the immunoproteasome is thought to primarily function in adaptive immune responses. However, recent studies indicate an association of immunoproteasomes with many physiological disorders such as cancer, neurodegenerative, and inflammatory diseases. Despite this, the detailed functions of the immunoproteasome remain poorly understood. Immunoproteasome-specific probes are essential to gain insight into immunoproteasome function. Here, we describe for the first time the development of cell-permeable activity-based fluorescent probes, UK101-Fluor and UK101-B660, which selectively target the catalytically active LMP2/β1i subunit of the immunoproteasome. These probes facilitate rapid detection of the cellular localization of catalytically active immunoproteasomes in living cells, providing a valuable tool to analyze immunoproteasome functions. Additionally, as LMP2/β1i may serve as a potential tumor biomarker, an LMP2/β1i-targeting fluorescent imaging probe may be applicable to a rapid readout assay to determine tumor LMP2/β1i levels.
Collapse
Affiliation(s)
- Kimberly Cornish Carmony
- Department of Pharmaceutical Science, College of Pharmacy, University of Kentucky, Lexington, KY 40536, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
98
|
Hänzelmann P, Schäfer A, Völler D, Schindelin H. Structural insights into functional modes of proteins involved in ubiquitin family pathways. Methods Mol Biol 2012; 832:547-76. [PMID: 22350912 DOI: 10.1007/978-1-61779-474-2_39] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The conjugation of ubiquitin and related modifiers to selected proteins represents a general mechanism to alter the function of these protein targets, thereby increasing the complexity of the cellular proteome. Ubiquitylation is catalyzed by a hierarchical enzyme cascade consisting of ubiquitin activating, ubiquitin conjugating, and ubiquitin ligating enzymes, and their combined action results in a diverse topology of ubiquitin-linkages on the modified proteins. Counteracting this machinery are various deubiquitylating enzymes while ubiquitin recognition in all its facets is accomplished by numerous ubiquitin-binding elements. In the following chapter, we attempt to provide an overview on enzymes involved in ubiquitylation as well as the removal of ubiquitin and proteins involved in the recognition and binding of ubiquitin from a structural biologist's perspective.
Collapse
Affiliation(s)
- Petra Hänzelmann
- Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
| | | | | | | |
Collapse
|
99
|
Ponts N, Saraf A, Chung DWD, Harris A, Prudhomme J, Washburn MP, Florens L, Le Roch KG. Unraveling the ubiquitome of the human malaria parasite. J Biol Chem 2011; 286:40320-30. [PMID: 21930698 PMCID: PMC3220526 DOI: 10.1074/jbc.m111.238790] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2011] [Revised: 09/13/2011] [Indexed: 11/06/2022] Open
Abstract
Malaria is one of the deadliest infectious diseases worldwide. The most severe form is caused by the eukaryotic protozoan parasite Plasmodium falciparum. Recent studies have highlighted the importance of post-translational regulations for the parasite's progression throughout its life cycle, protein ubiquitylation being certainly one of the most abundant. The specificity of its components and the wide range of biological processes in which it is involved make the ubiquitylation pathway a promising source of suitable targets for anti-malarial drug development. Here, we combined immunofluorescent microscopy, biochemical assays, in silico prediction, and mass spectrometry analysis using the multidimensional protein identification technology, or MudPIT, to describe the P. falciparum ubiquitome. We found that ubiquitin conjugates are detected at every morphological stage of the parasite erythrocytic cycle. Furthermore, we detected that more than half of the parasite's proteome represents possible targets for ubiquitylation, especially proteins found to be present at the most replicative stage of the asexual cycle, the trophozoite stage. A large proportion of ubiquitin conjugates were also detected at the schizont stage, consistent with a cell activity slowdown to prepare for merozoite differentiation and invasion. Finally, for the first time in the human malaria parasite, our results strongly indicate the presence of heterologous mixed conjugations, SUMO/UB. This discovery suggests that sumoylated proteins may be regulated by ubiquitylation in P. falciparum. Altogether, our results present the first stepping stone toward a better understanding of ubiquitylation and its role(s) in the biology of the human malaria parasite.
Collapse
Affiliation(s)
- Nadia Ponts
- From the Department of Cell Biology and Neuroscience, University of California, Riverside, California 92521 and
| | - Anita Saraf
- the Stowers Institute for Medical Research, Kansas City, Missouri 64110
| | - Duk-Won D. Chung
- From the Department of Cell Biology and Neuroscience, University of California, Riverside, California 92521 and
| | - Alona Harris
- From the Department of Cell Biology and Neuroscience, University of California, Riverside, California 92521 and
| | - Jacques Prudhomme
- From the Department of Cell Biology and Neuroscience, University of California, Riverside, California 92521 and
| | | | - Laurence Florens
- the Stowers Institute for Medical Research, Kansas City, Missouri 64110
| | - Karine G. Le Roch
- From the Department of Cell Biology and Neuroscience, University of California, Riverside, California 92521 and
| |
Collapse
|
100
|
Soucy TA, Dick LR, Smith PG, Milhollen MA, Brownell JE. The NEDD8 Conjugation Pathway and Its Relevance in Cancer Biology and Therapy. Genes Cancer 2011; 1:708-16. [PMID: 21779466 DOI: 10.1177/1947601910382898] [Citation(s) in RCA: 171] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Cancer cells depend on signals that promote cell cycle progression and prevent programmed cell death that would otherwise result from cumulative, aberrant stress. These activities require the temporally controlled destruction of specific intracellular proteins by the ubiquitin-proteasome system (UPS). To a large extent, the control points in this process include a family of E3 ubiquitin ligases called cullin-RING ligases (CRLs). The ligase activity of these multicomponent complexes requires modification of the cullin protein situated at their core with a ubiquitin-like protein called NEDD8. Neddylation results in conformational rearrangements within the CRL, which are necessary for ubiquitin transfer to a substrate. The NEDD8 pathway thus has a critical role in mediating the ubiquitination of numerous CRL substrate proteins involved in cell cycle progression and survival including the DNA replication licensing factor Cdt-1, the NF-κB transcription factor inhibitor pIκBα, and the cell cycle regulators cyclin E and p27. The initial step required for attachment of NEDD8 to a cullin is catalyzed by the E1, NEDD8-activating enzyme (NAE). The first-in-class inhibitor of NAE, MLN4924, has been shown to block the activity of NAE and prevent the subsequent neddylation of cullins. Preclinical studies have demonstrated antitumor activity in various solid tumors and hematological malignancies, and preliminary clinical data have shown the anticipated pharmacodynamic effects in humans. Here, we review the NEDD8 pathway, its importance in cancer, and the therapeutic potential of NAE inhibition.
Collapse
|