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Gui W, Kodadek T. Facile Synthesis of Homodimeric Protein Ligands. Chembiochem 2023; 24:e202300392. [PMID: 37449865 PMCID: PMC10615197 DOI: 10.1002/cbic.202300392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 07/11/2023] [Accepted: 07/12/2023] [Indexed: 07/18/2023]
Abstract
Many proteins exist as oligomers (homodimers, homotrimers, etc.). A proven strategy for the development of high affinity ligands for such targets is to link together two modest affinity ligands that allows the formation of a 2 : 2 (or higher-order) protein-ligand complex. We report here the discovery of a convenient, "click-like" reaction for the homodimerization of protein ligands that is efficient, operationally simple to carry out, and tolerant of many functional groups. This chemistry reduces the synthetic burden inherent in the creation of homodimeric ligands since only a single precursor is required. The utility of this strategy is demonstrated by the synthesis of homodimeric inhibitors, including PROTACs.
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Affiliation(s)
- Weijun Gui
- Department of Chemistry, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, 120 Scripps Way, Jupiter, FL 33458, USA
| | - Thomas Kodadek
- Department of Chemistry, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, 120 Scripps Way, Jupiter, FL 33458, USA
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Gui W, Kodadek T. Applications and Limitations of Oxime-Linked "Split PROTACs". Chembiochem 2022; 23:e202200275. [PMID: 35802347 PMCID: PMC9594079 DOI: 10.1002/cbic.202200275] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 07/07/2022] [Indexed: 11/10/2022]
Abstract
Proteolysis targeting chimeras are of keen interest as probe molecules and drug leads. Their activity is highly sensitive to the length and nature of the linker connecting the E3 Ubiquitin Ligase (E3 Ubl) and target protein (TP) ligands, which therefore requires tedious optimization. The creation of "split PROTACs" from E3 Ubl and TP ligands modified with residues suitable for them to couple when simply mixed together would allow various combinations to be assessed in a combinatorial fashion, thus greatly easing the workload relative to a one-by-one synthesis of many different PROTACs (proteolysis targeting chimeras). We explore oxime chemistry here for this purpose. We show that PROTAC assembly occurs efficiently when the components are mixed at a high concentration, then added to cells. However, in situ coupling of the TP and E3 Ubl ligands is inefficient when these units are added to cells at lower concentrations.
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Affiliation(s)
- Weijun Gui
- Department of Chemistry, UF Scripps Biomedical Research, 120 Scripps Way, Jupiter, FL 33458, USA
| | - Thomas Kodadek
- Department of Chemistry, UF Scripps Biomedical Research, 120 Scripps Way, Jupiter, FL 33458, USA
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Mathó C, Fernández MC, Bonanata J, Liu XD, Martin A, Vieites A, Sansó G, Barontini M, Jonasch E, Coitiño EL, Pennisi PA. VHL-P138R and VHL-L163R Novel Variants: Mechanisms of VHL Pathogenicity Involving HIF-Dependent and HIF-Independent Actions. Front Endocrinol (Lausanne) 2022; 13:854365. [PMID: 35388293 PMCID: PMC8978939 DOI: 10.3389/fendo.2022.854365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 02/15/2022] [Indexed: 11/21/2022] Open
Abstract
The von Hippel-Lindau (VHL) disease is an autosomal dominant cancer syndrome caused by mutations in the VHL tumor suppressor gene. VHL protein (pVHL) forms a complex (VBC) with Elongins B-C, Cullin2, and Rbx1. Although other functions have been discovered, the most described function of pVHL is to recognize and target hypoxia-inducible factor (HIF) for degradation. This work comprises the functional characterization of two novel variants of the VHL gene (P138R and L163R) that have been described in our center in patients with VHL disease by in vitro, in vivo, and in silico approaches. In vitro, we found that these variants have a significantly shorter half-life compared to wild-type VHL but still form a functional VBC complex. Altered fibronectin deposition was evidenced for both variants using immunofluorescence. In vivo studies revealed that both variants failed to suppress tumor growth. By means of molecular dynamics simulations, we inspected in silico the nature of the changes introduced by each variant in the VBC complex. We have demonstrated the pathogenicity of P138R and L163R novel variants, involving HIF-dependent and HIF-independent mechanisms. These results provide the basis for future studies regarding the impact of structural alterations on posttranslational modifications that drive pVHL's fate and functions.
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Affiliation(s)
- Cecilia Mathó
- Centro de Investigaciones Endocrinológicas Dr. César Bergadá (CEDIE), Consejo Nacional de Investigaciones Científicas y Técnicas- Fundación de Endocrinología Infantil (CONICET-FEI) División de Endocrinología, Hospital de Niños Dr. Ricardo Gutiérrez, Buenos Aires, Argentina
| | - María Celia Fernández
- Centro de Investigaciones Endocrinológicas Dr. César Bergadá (CEDIE), Consejo Nacional de Investigaciones Científicas y Técnicas- Fundación de Endocrinología Infantil (CONICET-FEI) División de Endocrinología, Hospital de Niños Dr. Ricardo Gutiérrez, Buenos Aires, Argentina
| | - Jenner Bonanata
- Laboratorio de Química Teórica y Computacional (LQTC), Instituto de Química Biológica, Facultad de Ciencias and Centro de Investigaciones Biomédicas (CEINBIO), Universidad de la República, Montevideo, Uruguay
| | - Xian-De Liu
- University of Texas MD Anderson Cancer Center, Houston, TX, United States
| | - Ayelen Martin
- Centro de Investigaciones Endocrinológicas Dr. César Bergadá (CEDIE), Consejo Nacional de Investigaciones Científicas y Técnicas- Fundación de Endocrinología Infantil (CONICET-FEI) División de Endocrinología, Hospital de Niños Dr. Ricardo Gutiérrez, Buenos Aires, Argentina
| | - Ana Vieites
- Centro de Investigaciones Endocrinológicas Dr. César Bergadá (CEDIE), Consejo Nacional de Investigaciones Científicas y Técnicas- Fundación de Endocrinología Infantil (CONICET-FEI) División de Endocrinología, Hospital de Niños Dr. Ricardo Gutiérrez, Buenos Aires, Argentina
| | - Gabriela Sansó
- Centro de Investigaciones Endocrinológicas Dr. César Bergadá (CEDIE), Consejo Nacional de Investigaciones Científicas y Técnicas- Fundación de Endocrinología Infantil (CONICET-FEI) División de Endocrinología, Hospital de Niños Dr. Ricardo Gutiérrez, Buenos Aires, Argentina
| | - Marta Barontini
- Centro de Investigaciones Endocrinológicas Dr. César Bergadá (CEDIE), Consejo Nacional de Investigaciones Científicas y Técnicas- Fundación de Endocrinología Infantil (CONICET-FEI) División de Endocrinología, Hospital de Niños Dr. Ricardo Gutiérrez, Buenos Aires, Argentina
| | - Eric Jonasch
- University of Texas MD Anderson Cancer Center, Houston, TX, United States
| | - E. Laura Coitiño
- Laboratorio de Química Teórica y Computacional (LQTC), Instituto de Química Biológica, Facultad de Ciencias and Centro de Investigaciones Biomédicas (CEINBIO), Universidad de la República, Montevideo, Uruguay
| | - Patricia Alejandra Pennisi
- Centro de Investigaciones Endocrinológicas Dr. César Bergadá (CEDIE), Consejo Nacional de Investigaciones Científicas y Técnicas- Fundación de Endocrinología Infantil (CONICET-FEI) División de Endocrinología, Hospital de Niños Dr. Ricardo Gutiérrez, Buenos Aires, Argentina
- *Correspondence: Patricia Alejandra Pennisi,
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Buart S, Terry S, Diop MK, Dessen P, Couvé S, Abdou A, Adam J, Thiery J, Savagner P, Chouaib S. The Most Common VHL Point Mutation R167Q in Hereditary VHL Disease Interferes with Cell Plasticity Regulation. Cancers (Basel) 2021; 13:3897. [PMID: 34359798 PMCID: PMC8345752 DOI: 10.3390/cancers13153897] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 07/26/2021] [Accepted: 07/28/2021] [Indexed: 01/16/2023] Open
Abstract
Von Hippel-Lindau disease (VHL) is a rare hereditary syndrome due to mutations of the VHL tumor suppressor gene. Patients harboring the R167Q mutation of the VHL gene have a high risk of developing ccRCCs. We asked whether the R167Q mutation with critical aspects of pseudo-hypoxia interferes with tumor plasticity. For this purpose, we used wild-type VHL (WT-VHL) and VHL-R167Q reconstituted cells. We showed that WT-VHL and VHL-R167Q expression had a similar effect on cell morphology and colony formation. However, cells transfected with VHL-R167Q display an intermediate, HIF2-dependent, epithelial-mesenchymal phenotype. Using RNA sequencing, we showed that this mutation upregulates the expression of genes involved in the hypoxia pathway, indicating that such mutation is conferring an enhanced pseudo-hypoxic state. Importantly, this hypoxic state correlates with the induction of genes belonging to epithelial-mesenchymal transition (EMT) and stemness pathways, as revealed by GSEA TCGA analysis. Moreover, among these deregulated genes, we identified nine genes specifically associated with a poor patient survival in the TCGA KIRC dataset. Together, these observations support the hypothesis that a discrete VHL point mutation interferes with tumor plasticity and may impact cell behavior by exacerbating phenotypic switching. A better understanding of the role of this mutation might guide the search for more effective treatments to combat ccRCCs.
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Affiliation(s)
- Stéphanie Buart
- INSERM UMR 1186, Integrative Tumor Immunology and Immunotherapy, Gustave Roussy, Faculty of Medicine, University Paris-Saclay, 94805 Villejuif, France; (S.B.); (S.T.); (A.A.); (J.A.); (J.T.); (P.S.)
| | - Stéphane Terry
- INSERM UMR 1186, Integrative Tumor Immunology and Immunotherapy, Gustave Roussy, Faculty of Medicine, University Paris-Saclay, 94805 Villejuif, France; (S.B.); (S.T.); (A.A.); (J.A.); (J.T.); (P.S.)
| | - M’boyba Khadija Diop
- Bioinformatics Core Facility, University of Paris-Saclay, 94805 Villejuif, France; (M.K.D.); (P.D.)
| | - Philippe Dessen
- Bioinformatics Core Facility, University of Paris-Saclay, 94805 Villejuif, France; (M.K.D.); (P.D.)
| | - Sophie Couvé
- EPHE, PSL Université, 75006 Paris, France;
- CNRS UMR 9019, Gustave Roussy, University Paris-Saclay, 94805 Villejuif, France
| | - Abdérémane Abdou
- INSERM UMR 1186, Integrative Tumor Immunology and Immunotherapy, Gustave Roussy, Faculty of Medicine, University Paris-Saclay, 94805 Villejuif, France; (S.B.); (S.T.); (A.A.); (J.A.); (J.T.); (P.S.)
| | - Julien Adam
- INSERM UMR 1186, Integrative Tumor Immunology and Immunotherapy, Gustave Roussy, Faculty of Medicine, University Paris-Saclay, 94805 Villejuif, France; (S.B.); (S.T.); (A.A.); (J.A.); (J.T.); (P.S.)
- Biology and Pathology Department, University Paris-Saclay, 94805 Villejuif, France
| | - Jérôme Thiery
- INSERM UMR 1186, Integrative Tumor Immunology and Immunotherapy, Gustave Roussy, Faculty of Medicine, University Paris-Saclay, 94805 Villejuif, France; (S.B.); (S.T.); (A.A.); (J.A.); (J.T.); (P.S.)
| | - Pierre Savagner
- INSERM UMR 1186, Integrative Tumor Immunology and Immunotherapy, Gustave Roussy, Faculty of Medicine, University Paris-Saclay, 94805 Villejuif, France; (S.B.); (S.T.); (A.A.); (J.A.); (J.T.); (P.S.)
| | - Salem Chouaib
- INSERM UMR 1186, Integrative Tumor Immunology and Immunotherapy, Gustave Roussy, Faculty of Medicine, University Paris-Saclay, 94805 Villejuif, France; (S.B.); (S.T.); (A.A.); (J.A.); (J.T.); (P.S.)
- Thumbay Research Institute for Precision Medicine, Gulf Medical University, Ajman 4184, United Arab Emirates
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Sweeney AT, Srivoleti P, Blake MA. Management of the patient with incidental bilateral adrenal nodules. JOURNAL OF CLINICAL AND TRANSLATIONAL ENDOCRINOLOGY CASE REPORTS 2021. [DOI: 10.1016/j.jecr.2021.100082] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
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Bao M, Li P, Li Q, Chen H, Zhong Y, Li S, Jin L, Wang W, Chen Z, Zhong J, Geng B, Fan Y, Yang X, Cai J. Genetic screening for monogenic hypertension in hypertensive individuals in a clinical setting. J Med Genet 2020; 57:571-580. [PMID: 32561571 PMCID: PMC7418625 DOI: 10.1136/jmedgenet-2019-106145] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 10/15/2019] [Accepted: 10/18/2019] [Indexed: 01/22/2023]
Abstract
BACKGROUND Monogenic hypertension describe a series of hypertensive syndromes that are inherited by Mendelian laws. Sometimes genetic testing is required to provide evidence for their diagnoses, precise classification and targeted treatment. This study is the first to investigate the clinical utility of a causative gene screening and the combined yield of gene product expression analyses in cases with suspected monogenic hypertension. METHODS We performed a large-scale multi-centre clinical genetic research of 1179 expertly selected hypertensive individuals from the Chinese Han population. Targeted sequencing were performed to evaluate 37 causative genes of potential cases of monogenic hypertension. Pathogenic and likely pathogenic variants were classified using the American College of Medical Genetics guidelines. Additionally, 49 variants of unknown significance (VUS) that had relatively high pathogenicity were selected and analysed using immunoblot protein expression assays. RESULTS 21 pathogenic or likely pathogenic variants were identified in 33 of 1179 cases (2.80%). Gene product expression analyses showed 27 VUSs harboured by 49 individuals (4.16%) could lead to abnormally expressed protein levels. Consequently, combining genetic screening with gene product expression analyses increased the diagnostic yield from 2.80% to 6.79%. The main aetiologies established were primary aldosteronism (PA; 27, 2.29%) and pheochromocytoma and paraganglioma (PPGL; 10, 0.85%). CONCLUSION Molecular diagnoses obtained using causative gene screening combined with gene product expression analyses initially achieved a modest diagnostic yield. Our data highlight the predominant roles of PA and PPGL. Furthermore, we provide evidence indicating the enhanced diagnostic ability of combined genetic and functional evaluation.
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Affiliation(s)
- Minghui Bao
- Department of Cardiology, Peking University First Hospital, Peking University, Beijing, China
| | - Ping Li
- Department of Cardiovascular Medicine, Nanchang University Second Affiliated Hospital, Nanchang, China
| | - Qifu Li
- Department of Endocrinology, Chongqing Medical University First Affiliated Hospital, Chongqing, China
| | - Hui Chen
- Department of Internal Medicine, Shengli Clinical Medical College of Fujian Medical University, Fuzhou, China
| | - Ying Zhong
- Novogene Science and Technology Co., Ltd, Beijing, China
| | - Shuangyue Li
- Hypertension Center of Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Ling Jin
- Hypertension Center of Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Wenjie Wang
- Hypertension Center of Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Zhenzhen Chen
- Hypertension Center of Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Jiuchang Zhong
- Heart Center and Beijing Key Laboratory of Hypertension, Beijing Chaoyang Hospital Affiliated to Capital Medical University, Beijing, China
| | - Bin Geng
- Hypertension Center of Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yuxin Fan
- The John Welsh Cardiovascular Diagnostic Laboratory, Baylor College of Medicine, Houston, Texas, USA
| | - Xinchun Yang
- Heart Center and Beijing Key Laboratory of Hypertension, Beijing Chaoyang Hospital Affiliated to Capital Medical University, Beijing, China
| | - Jun Cai
- Hypertension Center of Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
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Arginine refolds, stabilizes, and restores function of mutant pVHL proteins in animal model of the VHL cancer syndrome. Oncogene 2018; 38:1038-1049. [PMID: 30194449 DOI: 10.1038/s41388-018-0491-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 05/09/2018] [Accepted: 08/15/2018] [Indexed: 01/01/2023]
Abstract
The von Hippel-Lindau (VHL) syndrome is a rare inherited cancer, caused by mutations in the VHL gene, many of which render the VHL protein (pVHL) unstable. pVHL is a tumor-suppressor protein implicated in a variety of cellular processes, most notably in response to changes in oxygen availability, due to its role as part of an E3-ligase complex which targets the hypoxia-inducible factor (HIF) for degradation. Previously we reported, using in silico and in vitro analyses, that common oncogenic VHL mutations render pVHL less stable than the wild-type protein, distort its core domain and as a result reduce the ability of the protein to bind its target HIF-1α. Among various chemical chaperones tested, arginine was the most effective in refolding mutant of pVHL. Here we examined the consequences of administering L- or D-arginine to a Drosophila VHL model and to human renal carcinoma cells, both expressing misfolded versions of human pVHL. Arginine treatment increased pVHL solubility in both models and increased the half-life of the mutant pVHL proteins in the cell culture. In both models, L- as well as D-arginine enhanced the ability of wild-type pVHL and certain misfolded mutant versions of pVHL to bind ODD, the HIF-derived target peptide, reflecting restoration of pVHL function. Moreover, continuous feeding of Drosophila expressing misfolded versions of pVHL either L- or D-arginine rich diet rescued their lethal phenotype. Collectively, these in vivo results suggest that arginine supplementation should be examined as a potential novel treatment for VHL cancer syndrome.
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Maniaci C, Hughes SJ, Testa A, Chen W, Lamont DJ, Rocha S, Alessi DR, Romeo R, Ciulli A. Homo-PROTACs: bivalent small-molecule dimerizers of the VHL E3 ubiquitin ligase to induce self-degradation. Nat Commun 2017; 8:830. [PMID: 29018234 PMCID: PMC5635026 DOI: 10.1038/s41467-017-00954-1] [Citation(s) in RCA: 168] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Accepted: 08/01/2017] [Indexed: 01/09/2023] Open
Abstract
E3 ubiquitin ligases are key enzymes within the ubiquitin proteasome system which catalyze the ubiquitination of proteins, targeting them for proteasomal degradation. E3 ligases are gaining importance as targets to small molecules, both for direct inhibition and to be hijacked to induce the degradation of non-native neo-substrates using bivalent compounds known as PROTACs (for ‘proteolysis-targeting chimeras’). We describe Homo-PROTACs as an approach to dimerize an E3 ligase to trigger its suicide-type chemical knockdown inside cells. We provide proof-of-concept of Homo-PROTACs using diverse molecules composed of two instances of a ligand for the von Hippel-Lindau (VHL) E3 ligase. The most active compound, CM11, dimerizes VHL with high avidity in vitro and induces potent, rapid and proteasome-dependent self-degradation of VHL in different cell lines, in a highly isoform-selective fashion and without triggering a hypoxic response. This approach offers a novel chemical probe for selective VHL knockdown, and demonstrates the potential for a new modality of chemical intervention on E3 ligases. Targeting the ubiquitin proteasome system to modulate protein homeostasis using small molecules has promising therapeutic potential. Here the authors describe Homo-PROTACS: small molecules that can induce the homo-dimerization of E3 ubiquitin ligases and cause their proteasome-dependent degradation.
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Affiliation(s)
- Chiara Maniaci
- Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, James Black Centre, Dow Street, Dundee, Scotland, DD1 5EH, UK.,Medical Research Council Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, James Black Centre, Dow Street, Dundee, Scotland, DD1 5EH, UK
| | - Scott J Hughes
- Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, James Black Centre, Dow Street, Dundee, Scotland, DD1 5EH, UK
| | - Andrea Testa
- Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, James Black Centre, Dow Street, Dundee, Scotland, DD1 5EH, UK
| | - Wenzhang Chen
- Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, James Black Centre, Dow Street, Dundee, Scotland, DD1 5EH, UK
| | - Douglas J Lamont
- Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, James Black Centre, Dow Street, Dundee, Scotland, DD1 5EH, UK
| | - Sonia Rocha
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, James Black Centre, Dow Street, Dundee, DD1 5EH, Scotland, UK
| | - Dario R Alessi
- Medical Research Council Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, James Black Centre, Dow Street, Dundee, Scotland, DD1 5EH, UK
| | - Roberto Romeo
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina, Polo Universitario Viale SS. Annunziata SNC, Messina, 98168, Italy
| | - Alessio Ciulli
- Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, James Black Centre, Dow Street, Dundee, Scotland, DD1 5EH, UK.
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Shmueli MD, Hizkiahou N, Peled S, Gazit E, Segal D. Total proteome turbidity assay for tracking global protein aggregation in the natural cellular environment. J Biol Methods 2017; 4:e69. [PMID: 31453227 PMCID: PMC6706124 DOI: 10.14440/jbm.2017.148] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Revised: 02/07/2017] [Accepted: 02/08/2017] [Indexed: 01/10/2023] Open
Abstract
Proteome homeostasis is crucial for optimal cellular function and survival in the face of various stressful impacts. This entails preservation of a balance between protein synthesis, folding, degradation, and trafficking collectively termed proteostasis. A hallmark of proteostasis failure, which underlies various diseases, is enhanced misfolding and aggregation of proteins. Here we adapted the measurement of protein turbidity, which is commonly used to evaluate aggregation of single purified proteins, for monitoring propensity for aggregation of the entire soluble cellular proteome incubated in vitro for several hours. We show that over-expression of an aggregation-prone protein or applying endoplasmic-reticulum (ER) stress to either cells in culture or to the intact organism, Drosophila, enhances the rise in turbidity of the global soluble proteome compared to untreated cells. Additionally, given that Alzheimer's disease (AD) is known to involve ER stress and aggregation of proteins, we demonstrate that the soluble fraction of brain extracts from AD patients displays markedly higher rise of global proteome turbidity than in healthy counterparts. This assay could be valuable for various biological, medical and biotechnological applications.
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Affiliation(s)
- Merav D Shmueli
- Department of Molecular Microbiology and Biotechnology and the Interdisciplinary Sagol School of Neurosciences, George S. Wise Faculty of Life Sciences, Aviv University, Aviv 69978, Israel
| | - Noa Hizkiahou
- Department of Molecular Microbiology and Biotechnology and the Interdisciplinary Sagol School of Neurosciences, George S. Wise Faculty of Life Sciences, Aviv University, Aviv 69978, Israel
| | - Sivan Peled
- Department of Molecular Microbiology and Biotechnology and the Interdisciplinary Sagol School of Neurosciences, George S. Wise Faculty of Life Sciences, Aviv University, Aviv 69978, Israel
| | - Ehud Gazit
- Department of Molecular Microbiology and Biotechnology and the Interdisciplinary Sagol School of Neurosciences, George S. Wise Faculty of Life Sciences, Aviv University, Aviv 69978, Israel
| | - Daniel Segal
- Department of Molecular Microbiology and Biotechnology and the Interdisciplinary Sagol School of Neurosciences, George S. Wise Faculty of Life Sciences, Aviv University, Aviv 69978, Israel
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Molecular Characterization of a Novel Germline VHL Mutation by Extensive In Silico Analysis in an Indian Family with Von Hippel-Lindau Disease. GENETICS RESEARCH INTERNATIONAL 2016; 2016:9872594. [PMID: 27069690 PMCID: PMC4812357 DOI: 10.1155/2016/9872594] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2015] [Accepted: 02/17/2016] [Indexed: 11/17/2022]
Abstract
Von Hippel-Lindau [VHL] disease, an autosomal dominant hereditary cancer syndrome, is well known for its complex genotype-phenotype correlations. We looked for germline mutations in the VHL gene in an affected multiplex family with Type 1 VHL disease. Real-Time quantitative PCR for deletions and Sanger sequencing of coding regions along with flanking intronic regions were performed in two affected individuals and one related individual. Direct sequencing identified a novel heterozygous single nucleotide base substitution in both the affected members tested, segregating with VHL phenotype in this family. This variant in exon 3, c.473T>A, results in substitution of leucine, a highly conserved acid, to glutamine at position 158 [p.L158Q] and has not been reported thus far as a variant associated with disease causation. Further, this variant was not observed in 50 age and ethnicity matched healthy individuals. Extensive in silico prediction analysis along with molecular dynamics simulation revealed significant deleterious nature of the substitution L158Q on pVHL. The results of this study when collated support the view that the missense variation p.L158Q in the Elongin C binding domain of pVHL may be disease causing.
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Differential effects of HIF-α isoforms on apoptosis in renal carcinoma cell lines. Cancer Cell Int 2015; 15:23. [PMID: 25729330 PMCID: PMC4342814 DOI: 10.1186/s12935-015-0175-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 02/10/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Germline mutations in the von Hippel-Lindau (VHL) tumor suppressor gene predispose individuals to clear cell renal carcinomas, hemangioblastomas, and pheochromocytomas. The VHL gene product forms an ubiquitin E3 ligase complex, with regulation of hypoxia-inducible factor alpha (HIF-α) as its best known function. Lack of VHL expression has been shown previously to sensitize renal cells to apoptosis caused by certain cellular stresses. In this report, the role of HIF-α in apoptosis was investigated using two parent VHL-null renal carcinoma cell lines. METHODS 786-O and RCC10 renal carcinoma cell lines with manipulated levels of VHL, HIF-1α, or HIF-2α were subjected to cellular stresses and analyzed by western blotting for the abundance of apoptotic markers. RESULTS Cell lines expressing mutant VHL proteins that were unable to regulate HIF-α had increased levels of apoptosis when irradiated with ultraviolet (UV) light. The influences of the two major isoforms of HIF-α, HIF-1α and HIF-2α, on apoptosis, were compared by creating cell lines in which levels of each isoform were modulated via short hairpin RNA interference. In UV-irradiated cells, HIF-2α expression was determined to promote apoptosis, whereas HIF-1α was anti-apoptotic. In cells deprived of either glucose or serum, HIF-1α expression was generally anti-apoptotic, while HIF-2α expression was observed to either promote apoptosis or have less of an influence on apoptosis, depending on the cell line used. CONCLUSIONS HIF-1α and HIF-2α exerted distinct effects in each of the conditions tested, with expression of HIF-1α largely blocking apoptosis and HIF-2α generally promoting apoptosis. These results reinforce that HIF-1α and HIF-2α have distinct biological roles and that their relative expression levels may influence some therapeutic interventions that are dependent on apoptosis.
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Doonachar A, Schoenfeld AR. Expression of PKC iota affects neuronal differentiation of PC12 cells at least partly independent of kinase function. ACTA ACUST UNITED AC 2014; 3:1-13. [PMID: 24910851 DOI: 10.4236/cellbio.2014.31001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Atypical PKC (aPKC) plays a role in establishing cell polarity and has been indicated in neuronal differentiation and polarization, including neurite formation in rat pheochromocytoma PC12 cells, albeit by unclear mechanisms. Here, the role of the aPKC isoform, PKC iota (PKCι), in the early neuronal differentiation of PC12 cells was investigated. NGF-treated PC12 cells with stably expressed exogenous wild-type PKCι showed decreased expression of a neuroendocrine marker, increased expression of a neuronal marker, and increased neurite formation. Stable expression of a kinase- inactive PKCι, but not constitutively active PKCι lacking a regulatory domain, had similar although less potent effects. Pharmacological inhibition of endogenous aPKC kinase activity in parental PC12 cells did not inhibit neurite formation, suggesting that some of the observed effects of PKCι expression on neuronal differentiation are kinase- independent. Interestingly, exogenous expression of wild-type and kinase-inactive PKCι had little effect on overall PKCι activity, but caused a decrease in PKC zeta (PKCζ) kinase activity, suggesting an interplay between the two isoforms that may underlie the observed results. Overall, these findings suggest that in PC12 and perhaps other neuroendocrine precursor cells, PKCι influences an early differentiation decision between the neuroendocrine (chromaffin) and sympathetic neuron cell lineages, potentially by affecting PKCζ function.
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Affiliation(s)
- Alana Doonachar
- Department of Biology, Adelphi University, Garden City, NY, USA
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Ding Z, German P, Bai S, Reddy AS, Liu XD, Sun M, Zhou L, Chen X, Zhao X, Wu C, Zhang S, Mills GB, Jonasch E. Genetic and pharmacological strategies to refunctionalize the von Hippel Lindau R167Q mutant protein. Cancer Res 2014; 74:3127-36. [PMID: 24755468 DOI: 10.1158/0008-5472.can-13-3213] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Aberrant von Hippel Lindau (VHL) protein function is the underlying driver of VHL-related diseases, including both sporadic and inherited clear cell renal cell carcinoma (ccRCC). About one third of VHL mutations are missense point mutations, with R167Q being the most common VHL point mutation in hereditary VHL disease. Although it has been studied extensively, the ability of VHL-R167Q to downregulate hypoxia-inducible factor 2α (HIF2α) is still controversial. In addition, the manner in which the mutation contributes to tumorigenesis is not fully understood. No therapeutic approach is available to target VHL-R167Q and similar missense point mutations. We analyzed VHL-R167Q proteostasis and function at normoxia, at hypoxia with different oxygen pressure, and in a xenograft mouse model. We showed that the protein levels of VHL-R167Q dictate its ability to downregulate HIF2α and suppress tumor growth. Strikingly, the proteasome inhibitors bortezomib and carfilzomib, which are currently in clinical use, stabilize VHL-R167Q and increase its ability to downregulate HIF2α. VHL-R167Q binds elongin C and elongin B with considerably less avidity than wild-type VHL does but retains residual capacity to generate a VHL-elongin C-elongin B complex, downregulate HIF2α, and suppress tumorigenesis, which could be rescued by increase of VHL-R167Q levels. Finally, we used in silico approaches and identified other missense VHL mutants in addition to VHL-R167Q that might be rescued by similar strategies. Thus, our studies revealed detailed information describing how VHL-R167Q contributes to tumorigenesis and identified a potential targeted therapy for ccRCC and other VHL-related disease in patients carrying VHL-R167Q or similar missense mutations.
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Affiliation(s)
- Zhiyong Ding
- Authors' Affiliations: Departments of Systems Biology, Genitourinary Medical Oncology, and Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, Texas; and Department of Neurosciences, School of Medicine, University of California at San Diego, La Jolla, California
| | - Peter German
- Authors' Affiliations: Departments of Systems Biology, Genitourinary Medical Oncology, and Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, Texas; and Department of Neurosciences, School of Medicine, University of California at San Diego, La Jolla, California
| | - Shanshan Bai
- Authors' Affiliations: Departments of Systems Biology, Genitourinary Medical Oncology, and Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, Texas; and Department of Neurosciences, School of Medicine, University of California at San Diego, La Jolla, California
| | - A Srinivas Reddy
- Authors' Affiliations: Departments of Systems Biology, Genitourinary Medical Oncology, and Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, Texas; and Department of Neurosciences, School of Medicine, University of California at San Diego, La Jolla, California
| | - Xian-De Liu
- Authors' Affiliations: Departments of Systems Biology, Genitourinary Medical Oncology, and Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, Texas; and Department of Neurosciences, School of Medicine, University of California at San Diego, La Jolla, California
| | - Mianen Sun
- Authors' Affiliations: Departments of Systems Biology, Genitourinary Medical Oncology, and Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, Texas; and Department of Neurosciences, School of Medicine, University of California at San Diego, La Jolla, California
| | - Lijun Zhou
- Authors' Affiliations: Departments of Systems Biology, Genitourinary Medical Oncology, and Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, Texas; and Department of Neurosciences, School of Medicine, University of California at San Diego, La Jolla, California
| | - Xiaohua Chen
- Authors' Affiliations: Departments of Systems Biology, Genitourinary Medical Oncology, and Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, Texas; and Department of Neurosciences, School of Medicine, University of California at San Diego, La Jolla, California
| | - Xiaobei Zhao
- Authors' Affiliations: Departments of Systems Biology, Genitourinary Medical Oncology, and Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, Texas; and Department of Neurosciences, School of Medicine, University of California at San Diego, La Jolla, California
| | - Chengbiao Wu
- Authors' Affiliations: Departments of Systems Biology, Genitourinary Medical Oncology, and Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, Texas; and Department of Neurosciences, School of Medicine, University of California at San Diego, La Jolla, California
| | - Shuxing Zhang
- Authors' Affiliations: Departments of Systems Biology, Genitourinary Medical Oncology, and Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, Texas; and Department of Neurosciences, School of Medicine, University of California at San Diego, La Jolla, California
| | - Gordon B Mills
- Authors' Affiliations: Departments of Systems Biology, Genitourinary Medical Oncology, and Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, Texas; and Department of Neurosciences, School of Medicine, University of California at San Diego, La Jolla, California
| | - Eric Jonasch
- Authors' Affiliations: Departments of Systems Biology, Genitourinary Medical Oncology, and Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, Texas; and Department of Neurosciences, School of Medicine, University of California at San Diego, La Jolla, California
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Cingoz S, van der Luijt RB, Kurt E, Apaydin M, Akkol I, Ozgen MH. A novel missense mutation (N78D) in a family with von Hippel-Lindau disease with central nervous system haemangioblastomas, pancreatic and renal cysts. Fam Cancer 2013; 12:111-7. [PMID: 23224817 DOI: 10.1007/s10689-012-9586-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
von Hippel-Lindau (VHL) disease is a hereditary tumor syndrome caused by mutations in the VHL tumor suppressor gene. In a family with VHL, we identified a novel missense mutation (N78D), which affects a fully conserved residue in the VHL protein. Interestingly, several other missense mutations reported at same codon in the VHL protein that might be associated with a low risk of renal cell carcinoma (RCC) but not pheochromocytoma appear to be associated with a VHL type 1 phenotype. At the moment, RCC is present in none of the affected mutation carriers in the family described here. In contrast to other missense changes at codon 78, the change in our VHL family is predicted to have a mild effect on VHL function, which apparently is insufficient to cause predisposition to RCC. Our findings suggest that the risk of RCC in VHL is attributable to the severity of the amino acid substitution at this particular codon in the VHL protein.
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Affiliation(s)
- S Cingoz
- Department of Medical Biology and Genetic, School of Medicine, Dokuz Eylül University, Izmir, Turkey
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Mikhailenko DS, Grigor’eva MV, Rusakov IG, Kurynin RV, Popov AM, Peters MV, Matveev VB, Yakovleva ES, Nosov DA, Lyubchenko LN, Tulyandin SA, Strel’nikov VV, Zaletaev DV. Localization of point mutations in the coding part of the VHL gene in clear cell renal cancer. Mol Biol 2012. [DOI: 10.1134/s0026893311060070] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Chiatar SS, Eze OP, Schoenfeld AR. Expression of VHL Causes Three-Dimensional Morphological Changes in Renal Cells Indicative of Proximal Tubule Differentiation. ACTA ACUST UNITED AC 2012; 2. [PMID: 24308012 DOI: 10.4172/2168-9296.1000118] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Mutations in the von Hippel-Lindau (VHL) tumor suppressor gene are responsible for the VHL hereditary cancer syndrome, and are associated with the majority of clear cell renal cell carcinomas. In this study, scanning electron microscopy of VHL-negative renal carcinoma cells was utilized to examine the effects of VHL re-expression on the morphology of these cells. Significant differences were observed between the morphology of VHL-negative control cells and those with reintroduced VHL, with VHL expression mediating an apical surface that mounded upward, as opposed to the flat surfaces seen with VHL-negative cells. In long term cultures, rounded VHL-expressing cells grew in clusters on top the monolayer, and microvilli were observed on the apical face of these cells, in a manner suggestive of proximal tubule differentiation. In contrast, VHL-negative cells remained flat and did not develop microvilli in long-term cultures. Since VHL is a key member of an ubiquitin E3 ligase complex whose best known target is hypoxia-inducible factor alpha (HIF-α), we looked at the effects of HIF-α expression on cell morphology. Knockdown of HIF-2α in cells that only express this isoform had no effect on the morphology of the cells. These results indicate that VHL expression directs three dimensional morphological changes in renal cells indicative of differentiation, and while dysregulation of HIF-α may be necessary for tumorigenesis following VHL loss, it is not the major determinant of these VHL-mediated morphological changes.
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Rechsteiner MP, von Teichman A, Nowicka A, Sulser T, Schraml P, Moch H. VHL gene mutations and their effects on hypoxia inducible factor HIFα: identification of potential driver and passenger mutations. Cancer Res 2011; 71:5500-11. [PMID: 21715564 DOI: 10.1158/0008-5472.can-11-0757] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Mutations of the von Hippel-Lindau (VHL) gene are frequent in clear cell renal cell carcinomas (ccRCC). Nonsense and frameshift mutations abrogate the function of the VHL protein (pVHL), whereas missense mutations can have different effects. To identify those missense mutations with functional consequences, we sequenced VHL in 256 sporadic ccRCC and identified 187 different VHL mutations of which 65 were missense mutations. Location and destabilizing effects of VHL missense mutations were determined in silico. The majority of the thermodynamically destabilizing missense mutations were located in exon 1 in the core of pVHL, whereas protein surface mutations in exon 3 affected the interaction domains of elongin B and C. Their impact on pVHL's functionality was further investigated in vitro by stably reintroducing VHL missense mutations into a VHL null cell line and by monitoring the green fluorescent protein (GFP) signals after the transfection of a hypoxia inducible factor (HIF)α-GFP expression vector. pVHL's functionality ranged from no effect to complete HIF stabilization. Interestingly, Asn78Ser, Asp121Tyr, and Val130Phe selectively influenced HIF1α and HIF2α degradation. In summary, we obtained three different groups of missense mutations: one with severe destabilization of pVHL; a second without destabilizing effects on pVHL but relevance for the interaction with HIFα, elongin B, and elongin C; and a third with pVHL functions comparable with wild type. We therefore conclude that the specific impact of missense mutations may help to distinguish between driver and passenger mutations and may explain responses of ccRCC patients to HIF-targeted therapies.
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Drosophila von Hippel-Lindau tumor suppressor gene function in epithelial tubule morphogenesis. Mol Cell Biol 2010; 30:3779-94. [PMID: 20516215 DOI: 10.1128/mcb.01578-09] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Mutations in the human von Hippel-Lindau (VHL) gene are the cause of VHL disease that displays multiple benign and malignant tumors. The VHL gene has been shown to regulate angiogenic potential and glycolic metabolism via its E3 ubiquitin ligase function against the alpha subunit of hypoxia-inducible factor (HIF-alpha). However, many HIF-independent functions of VHL have been identified. Recent evidence also indicates that the canonical function cannot fully explain the VHL mutant cell phenotypes, although it is still unclear how many of these noncanonical functions relate to the pathophysiological processes because of a lack of tractable genetic systems. Here, we report the first genomic mutant phenotype of Drosophila melanogaster VHL (dVHL) in the epithelial tubule network, the trachea, and show that dVHL regulates branch migration and lumen formation via its endocytic function. The endocytic function regulates the surface level of the chemotactic signaling receptor Breathless and promotes clearing of the lumen matrix during maturation of the tracheal tubes. Importantly, the regulatory function in tubular morphogenesis is conserved in the mammalian system, as conditional knockout of Vhl in mouse kidney also resulted in similar cell motility and lumen phenotypes.
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