1
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Finci LI, Chakrabarti M, Gulten G, Finney J, Grose C, Fox T, Yang R, Nissley DV, McCormick F, Esposito D, Balius TE, Simanshu DK. Structural dynamics of RAF1-HSP90-CDC37 and HSP90 complexes reveal asymmetric client interactions and key structural elements. Commun Biol 2024; 7:260. [PMID: 38431713 PMCID: PMC10908828 DOI: 10.1038/s42003-024-05959-3] [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: 09/22/2023] [Accepted: 02/22/2024] [Indexed: 03/05/2024] Open
Abstract
RAF kinases are integral to the RAS-MAPK signaling pathway, and proper RAF1 folding relies on its interaction with the chaperone HSP90 and the cochaperone CDC37. Understanding the intricate molecular interactions governing RAF1 folding is crucial for comprehending this process. Here, we present a cryo-EM structure of the closed-state RAF1-HSP90-CDC37 complex, where the C-lobe of the RAF1 kinase domain binds to one side of the HSP90 dimer, and an unfolded N-lobe segment of the RAF1 kinase domain threads through the center of the HSP90 dimer. CDC37 binds to the kinase C-lobe, mimicking the N-lobe with its HxNI motif. We also describe structures of HSP90 dimers without RAF1 and CDC37, displaying only N-terminal and middle domains, which we term the semi-open state. Employing 1 μs atomistic simulations, energetic decomposition, and comparative structural analysis, we elucidate the dynamics and interactions within these complexes. Our quantitative analysis reveals that CDC37 bridges the HSP90-RAF1 interaction, RAF1 binds HSP90 asymmetrically, and that HSP90 structural elements engage RAF1's unfolded region. Additionally, N- and C-terminal interactions stabilize HSP90 dimers, and molecular interactions in HSP90 dimers rearrange between the closed and semi-open states. Our findings provide valuable insight into the contributions of HSP90 and CDC37 in mediating client folding.
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Affiliation(s)
- Lorenzo I Finci
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Mayukh Chakrabarti
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Gulcin Gulten
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Joseph Finney
- National Cryo-EM Facility, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Carissa Grose
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Tara Fox
- National Cryo-EM Facility, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Renbin Yang
- Center for Molecular Microscopy, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Dwight V Nissley
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Frank McCormick
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
- Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA, USA
| | - Dominic Esposito
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Trent E Balius
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Dhirendra K Simanshu
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA.
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2
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Somu P, Mohanty S, Basavegowda N, Yadav AK, Paul S, Baek KH. The Interplay between Heat Shock Proteins and Cancer Pathogenesis: A Novel Strategy for Cancer Therapeutics. Cancers (Basel) 2024; 16:638. [PMID: 38339390 PMCID: PMC10854888 DOI: 10.3390/cancers16030638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 01/29/2024] [Accepted: 01/30/2024] [Indexed: 02/12/2024] Open
Abstract
Heat shock proteins (HSPs) are developmentally conserved families of protein found in both prokaryotic and eukaryotic organisms. HSPs are engaged in a diverse range of physiological processes, including molecular chaperone activity to assist the initial protein folding or promote the unfolding and refolding of misfolded intermediates to acquire the normal or native conformation and its translocation and prevent protein aggregation as well as in immunity, apoptosis, and autophagy. These molecular chaperonins are classified into various families according to their molecular size or weight, encompassing small HSPs (e.g., HSP10 and HSP27), HSP40, HSP60, HSP70, HSP90, and the category of large HSPs that include HSP100 and ClpB proteins. The overexpression of HSPs is induced to counteract cell stress at elevated levels in a variety of solid tumors, including anticancer chemotherapy, and is closely related to a worse prognosis and therapeutic resistance to cancer cells. HSPs are also involved in anti-apoptotic properties and are associated with processes of cancer progression and development, such as metastasis, invasion, and cell proliferation. This review outlines the previously mentioned HSPs and their significant involvement in diverse mechanisms of tumor advancement and metastasis, as well as their contribution to identifying potential targets for therapeutic interventions.
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Affiliation(s)
- Prathap Somu
- Department of Biotechnology and Chemical Engineering, School of Civil & Chemical Engineering, Manipal University Jaipur, Dehmi Kalan, Jaipur 303007, India;
| | - Sonali Mohanty
- Department of Biotechnology and Medical Engineering, National Institute of Technology, Rourkela 769008, India;
| | - Nagaraj Basavegowda
- Department of Biotechnology, Yeungnam University, Gyeongsan 38451, Republic of Korea;
| | - Akhilesh Kumar Yadav
- Department of Environmental Engineering and Management, Chaoyang University of Technology, Taichung 413310, Taiwan;
- Department of Bioengineering, Saveetha School of Engineering, Saveetha Institute of Medical and Technical Sciences, Chennai 602105, India
| | - Subhankar Paul
- Department of Biotechnology and Medical Engineering, National Institute of Technology, Rourkela 769008, India;
| | - Kwang-Hyun Baek
- Department of Biotechnology, Yeungnam University, Gyeongsan 38451, Republic of Korea;
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3
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Amatya E, Blagg BSJ. Recent advances toward the development of Hsp90 C-terminal inhibitors. Bioorg Med Chem Lett 2023; 80:129111. [PMID: 36549397 PMCID: PMC9869726 DOI: 10.1016/j.bmcl.2022.129111] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 12/09/2022] [Accepted: 12/15/2022] [Indexed: 12/23/2022]
Abstract
Heat shock protein 90 (Hsp90) is a dynamic protein which serves to ensure proper folding of nascent client proteins, regulate transcriptional responses to environmental stress and guide misfolded and damaged proteins to destruction via ubiquitin proteasome pathway. Recent advances in the field of Hsp90 have been made through development of isoform selective inhibitors, Hsp90 C-terminal inhibitors and disruption of protein-protein interactions. These approaches have led to alleviation of adverse off-target effects caused by pan-inhibition of Hsp90 using N-terminal inhibitors. In this review, we provide an overview of relevant advances on targeting the Hsp90 C-terminal Domain (CTD) and the development of Hsp90 C-terminal inhibitors (CTIs) since 2015.
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Affiliation(s)
- Eva Amatya
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Brian S J Blagg
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA; Warren Family Research Center for Drug Discovery and Development, University of Notre Dame, Notre Dame, IN 46556, USA.
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4
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García-Alonso S, Mesa P, Ovejero LDLP, Aizpurua G, Lechuga CG, Zarzuela E, Santiveri CM, Sanclemente M, Muñoz J, Musteanu M, Campos-Olivas R, Martínez-Torrecuadrada J, Barbacid M, Montoya G. Structure of the RAF1-HSP90-CDC37 complex reveals the basis of RAF1 regulation. Mol Cell 2022; 82:3438-3452.e8. [PMID: 36055235 DOI: 10.1016/j.molcel.2022.08.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 06/21/2022] [Accepted: 08/08/2022] [Indexed: 10/14/2022]
Abstract
RAF kinases are RAS-activated enzymes that initiate signaling through the MAPK cascade to control cellular proliferation, differentiation, and survival. Here, we describe the structure of the full-length RAF1 protein in complex with HSP90 and CDC37 obtained by cryoelectron microscopy. The reconstruction reveals a RAF1 kinase with an unfolded N-lobe separated from its C-lobe. The hydrophobic core of the N-lobe is trapped in the HSP90 dimer, while CDC37 wraps around the chaperone and interacts with the N- and C-lobes of the kinase. The structure indicates how CDC37 can discriminate between the different members of the RAF family. Our structural analysis also reveals that the folded RAF1 assembles with 14-3-3 dimers, suggesting that after folding RAF1 follows a similar activation as B-RAF. Finally, disruption of the interaction between CDC37 and the DFG segment of RAF1 unveils potential vulnerabilities in attempting the pharmacological degradation of RAF1 for therapeutic purposes.
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Affiliation(s)
- Sara García-Alonso
- Experimental Oncology Group, Molecular Oncology Programme, Centro Nacional de Investigaciones Oncológicas (CNIO), Madrid 28029, Spain; Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Pablo Mesa
- Structural Molecular Biology Group, Novo Nordisk Foundation Centre for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark
| | - Laura de la Puente Ovejero
- Experimental Oncology Group, Molecular Oncology Programme, Centro Nacional de Investigaciones Oncológicas (CNIO), Madrid 28029, Spain
| | - Gonzalo Aizpurua
- Experimental Oncology Group, Molecular Oncology Programme, Centro Nacional de Investigaciones Oncológicas (CNIO), Madrid 28029, Spain
| | - Carmen G Lechuga
- Experimental Oncology Group, Molecular Oncology Programme, Centro Nacional de Investigaciones Oncológicas (CNIO), Madrid 28029, Spain
| | - Eduardo Zarzuela
- Proteomics Unit, Biotechnology Programme, Centro Nacional de Investigaciones Oncológicas (CNIO), Madrid 28029, Spain
| | - Clara M Santiveri
- Spectroscopy and NMR Unit, Structural Biology Programme, Centro Nacional de Investigaciones Oncológicas (CNIO), Madrid 28029, Spain
| | - Manuel Sanclemente
- Experimental Oncology Group, Molecular Oncology Programme, Centro Nacional de Investigaciones Oncológicas (CNIO), Madrid 28029, Spain
| | - Javier Muñoz
- Proteomics Unit, Biotechnology Programme, Centro Nacional de Investigaciones Oncológicas (CNIO), Madrid 28029, Spain
| | - Mónica Musteanu
- Department Section of Biochemistry and Molecular Biology, Complutense University of Madrid, Madrid 28040, Spain
| | - Ramón Campos-Olivas
- Spectroscopy and NMR Unit, Structural Biology Programme, Centro Nacional de Investigaciones Oncológicas (CNIO), Madrid 28029, Spain
| | - Jorge Martínez-Torrecuadrada
- Crystallography and Protein Engineering Unit, Structural Biology Programme, Centro Nacional de Investigaciones Oncológicas (CNIO), Madrid 28029, Spain
| | - Mariano Barbacid
- Experimental Oncology Group, Molecular Oncology Programme, Centro Nacional de Investigaciones Oncológicas (CNIO), Madrid 28029, Spain; Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), Instituto de Salud Carlos III, 28029 Madrid, Spain.
| | - Guillermo Montoya
- Structural Molecular Biology Group, Novo Nordisk Foundation Centre for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark.
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5
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Keramisanou D, Vasantha Kumar M, Boose N, Abzalimov RR, Gelis I. Assembly mechanism of early Hsp90-Cdc37-kinase complexes. SCIENCE ADVANCES 2022; 8:eabm9294. [PMID: 35294247 PMCID: PMC8926337 DOI: 10.1126/sciadv.abm9294] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 01/25/2022] [Indexed: 05/27/2023]
Abstract
Molecular chaperones have an essential role for the maintenance of a balanced protein homeostasis. Here, we investigate how protein kinases are recruited and loaded to the Hsp90-Cdc37 complex, the first step during Hsp90-mediated chaperoning that leads to enhanced client kinase stability and activation. We show that conformational dynamics of all partners is a critical feature of the underlying loading mechanism. The kinome co-chaperone Cdc37 exists primarily in a dynamic extended conformation but samples a low-populated, well-defined compact structure. Exchange between these two states is maintained in an assembled Hsp90-Cdc37 complex and is necessary for substrate loading. Breathing motions at the N-lobe of a free kinase domain partially expose the kinase segment trapped in the Hsp90 dimer downstream in the cycle. Thus, client dynamics poise for chaperone dependence. Hsp90 is not directly involved during loading, and Cdc37 is assigned the task of sensing clients by stabilizing the preexisting partially unfolded client state.
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Affiliation(s)
| | | | - Nicole Boose
- Department of Chemistry, University of South Florida, Tampa, FL 33620, USA
| | - Rinat R. Abzalimov
- Structural Biology Initiative, CUNY Advanced Science Research Center, New York, NY 10031, USA
| | - Ioannis Gelis
- Department of Chemistry, University of South Florida, Tampa, FL 33620, USA
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6
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Dai J, Chen A, Zhu M, Qi X, Tang W, Liu M, Li D, Gu Q, Li J. Penicisulfuranol A, a novel C-terminal inhibitor disrupting molecular chaperone function of Hsp90 independent of ATP binding domain. Biochem Pharmacol 2019; 163:404-415. [PMID: 30857829 DOI: 10.1016/j.bcp.2019.03.012] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2018] [Accepted: 03/07/2019] [Indexed: 12/30/2022]
Abstract
The goal of this study is to explore the mechanism of a heat shock protein 90 (Hsp90) C-terminal inhibitor, Penicisulfuranol A (PEN-A), for cancer therapy. PEN-A was produced by a mangrove endophytic fungus Penicillium janthinellum and had a new structure with a rare 3H-spiro [benzofuran-2, 2'-piperazine] ring system. PEN-A caused depletion of multiple Hsp90 client proteins without induction of heat shock protein 70 (Hsp70). Subsequently, it induced apoptosis and inhibited xerograph tumor growth of HCT116 cells in vitro and in vivo. Mechanism studies showed that PEN-A was bound to C-terminus of Hsp90 at the binding site different from ATP binding domain. Therefore, it inhibited dimerization of Hsp90 C-terminus, depolymerization of ADH protein by C-terminus of Hsp90, and interaction of co-chaperones with Hsp90. These inhibitory effects of PEN-A were similar to those of novobiocin, an inhibitor binding to interaction site for ATP of C-terminus of Hsp90. Furthermore, our study revealed that disulfide bond was essential moiety for inhibition activity of PEN-A on Hsp90. This suggested that PEN-A may be bound to cysteine residues near amino acid region which was responsible for dimerization of Hsp90. All results indicate that PEN-A is a novel C-terminal inhibitor of Hsp90 and worthy for further study in the future not only for drug development but also for unraveling the bioactivities of Hsp90.
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Affiliation(s)
- Jiajia Dai
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, PR China
| | - Ao Chen
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, PR China
| | - Meilin Zhu
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, PR China
| | - Xin Qi
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, PR China
| | - Wei Tang
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, PR China
| | - Ming Liu
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, PR China; Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, PR China
| | - Dehai Li
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, PR China; Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, PR China
| | - Qianqun Gu
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, PR China
| | - Jing Li
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, PR China; Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, PR China; Open Studio for Druggability Research of Marine Natural Products, Pilot National Laboratory for Marine Science and Technology (Qingdao), 1 Wenhai Road, Aoshanwei, Jimo, Qingdao 266237, PR China.
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7
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Synoradzki K, Miszta P, Kazlauskas E, Mickevičiūtė A, Michailovienė V, Matulis D, Filipek S, Bieganowski P. Interaction of the middle domains stabilizes Hsp90α dimer in a closed conformation with high affinity for p23. Biol Chem 2018; 399:337-345. [PMID: 29337688 DOI: 10.1515/hsz-2017-0172] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 12/14/2017] [Indexed: 01/10/2023]
Abstract
The human genome encodes two highly similar cytosolic Hsp90 proteins called isoforms Hsp90α and Hsp90β. Of the 300 client proteins for Hsp90 identified so far only a handful interact specifically with one Hsp90 isoform. Here we report for the first time that Hsp90 cochaperone p23 binds preferentially to Hsp90α and that this interaction is mediated by the middle domain of Hsp90α. Based on the homology modeling, we infer that the middle domains in the Hsp90α dimer bind stronger with each other than in the Hsp90β dimer. Therefore, compared to Hsp90β, Hsp90α may adopt closed conformation more easily. Hsp90 interacts with p23 in the closed conformation. Hsp90α binds human recombinant p23 about three times stronger than Hsp90β but with significantly smaller exothermic enthalpy as determined by isothermal titration calorimetry of direct binding between the purified proteins. As p23 binds to Hsp90 in a closed conformation, stabilization of the Hsp90α dimer in the closed conformation by its middle domains explains preference of p23 to this Hsp90 isoform.
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Affiliation(s)
- Kamil Synoradzki
- Department of Experimental Pharmacology, Mossakowski Medical Research Centre, Polish Academy of Sciences, 5 Pawinskiego St., 02-106 Warsaw, Poland
| | - Przemyslaw Miszta
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, 1 Pasteura St., 02-093 Warsaw, Poland
| | - Egidijus Kazlauskas
- Department of Biothermodynamics and Drug Design, Institute of Biotechnology, Vilnius University, Saulėtekio Al. 7, 10257 Vilnius, Lithuania
| | - Aurelija Mickevičiūtė
- Department of Biothermodynamics and Drug Design, Institute of Biotechnology, Vilnius University, Saulėtekio Al. 7, 10257 Vilnius, Lithuania
| | - Vilma Michailovienė
- Department of Biothermodynamics and Drug Design, Institute of Biotechnology, Vilnius University, Saulėtekio Al. 7, 10257 Vilnius, Lithuania
| | - Daumantas Matulis
- Department of Biothermodynamics and Drug Design, Institute of Biotechnology, Vilnius University, Saulėtekio Al. 7, 10257 Vilnius, Lithuania
| | - Slawomir Filipek
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, 1 Pasteura St., 02-093 Warsaw, Poland
| | - Pawel Bieganowski
- Department of Experimental Pharmacology, Mossakowski Medical Research Centre, Polish Academy of Sciences, 5 Pawinskiego St., 02-106 Warsaw, Poland
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8
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Kijima T, Prince TL, Tigue ML, Yim KH, Schwartz H, Beebe K, Lee S, Budzynski MA, Williams H, Trepel JB, Sistonen L, Calderwood S, Neckers L. HSP90 inhibitors disrupt a transient HSP90-HSF1 interaction and identify a noncanonical model of HSP90-mediated HSF1 regulation. Sci Rep 2018; 8:6976. [PMID: 29725069 PMCID: PMC5934406 DOI: 10.1038/s41598-018-25404-w] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 04/16/2018] [Indexed: 12/20/2022] Open
Abstract
Heat shock factor 1 (HSF1) initiates a broad transcriptional response to proteotoxic stress while also mediating a cancer-specific transcriptional program. HSF1 is thought to be regulated by molecular chaperones, including Heat Shock Protein 90 (HSP90). HSP90 is proposed to sequester HSF1 in unstressed cells, but visualization of this interaction in vivo requires protein crosslinking. In this report, we show that HSP90 binding to HSF1 depends on HSP90 conformation and is only readily visualized for the ATP-dependent, N-domain dimerized chaperone, a conformation only rarely sampled by mammalian HSP90. We have used this mutationally fixed conformation to map HSP90 binding sites on HSF1. Further, we show that ATP-competitive, N-domain targeted HSP90 inhibitors disrupt this interaction, resulting in the increased duration of HSF1 occupancy of the hsp70 promoter and significant prolongation of both the constitutive and heat-induced HSF1 transcriptional activity. While our data do not support a role for HSP90 in sequestering HSF1 monomers to suppress HSF1 transcriptional activity, our findings do identify a noncanonical role for HSP90 in providing dynamic modulation of HSF1 activity by participating in removal of HSF1 trimers from heat shock elements in DNA, thus terminating the heat shock response.
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Affiliation(s)
- Toshiki Kijima
- Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, 20892, United States
| | - Thomas L Prince
- Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, 20892, United States. .,Urology Department, Geisinger Clinic, WCR 221, Danville, PA, 17821, United States.
| | - Megan L Tigue
- Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, 20892, United States
| | - Kendrick H Yim
- Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, 20892, United States
| | - Harvey Schwartz
- Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, 20892, United States
| | - Kristin Beebe
- Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, 20892, United States
| | - Sunmin Lee
- Developmental Therapeutics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, 20892, United States
| | - Marek A Budzynski
- Faculty of Science and Engineering, Cell Biology, Åbo Akademi University, BioCity, Tykistökatu 6, Turku, FIN-20520, Finland
| | - Heinric Williams
- Urology Department, Geisinger Clinic, WCR 221, Danville, PA, 17821, United States
| | - Jane B Trepel
- Developmental Therapeutics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, 20892, United States
| | - Lea Sistonen
- Faculty of Science and Engineering, Cell Biology, Åbo Akademi University, BioCity, Tykistökatu 6, Turku, FIN-20520, Finland
| | - Stuart Calderwood
- Radiation Oncology, Harvard Medical School, Beth Israel Deaconess Medical Center, 330 Brookline Ave., Boston, MA, 02215, United States
| | - Len Neckers
- Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, 20892, United States.
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9
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Verba KA, Wang RYR, Arakawa A, Liu Y, Shirouzu M, Yokoyama S, Agard DA. Atomic structure of Hsp90-Cdc37-Cdk4 reveals that Hsp90 traps and stabilizes an unfolded kinase. Science 2016; 352:1542-7. [PMID: 27339980 DOI: 10.1126/science.aaf5023] [Citation(s) in RCA: 286] [Impact Index Per Article: 35.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 05/13/2016] [Indexed: 12/20/2022]
Abstract
The Hsp90 molecular chaperone and its Cdc37 cochaperone help stabilize and activate more than half of the human kinome. However, both the mechanism by which these chaperones assist their "client" kinases and the reason why some kinases are addicted to Hsp90 while closely related family members are independent are unknown. Our structural understanding of these interactions is lacking, as no full-length structures of human Hsp90, Cdc37, or either of these proteins with a kinase have been elucidated. Here we report a 3.9 angstrom cryo-electron microscopy structure of the Hsp90-Cdc37-Cdk4 kinase complex. Surprisingly, the two lobes of Cdk4 are completely separated with the β4-β5 sheet unfolded. Cdc37 mimics part of the kinase N lobe, stabilizing an open kinase conformation by wedging itself between the two lobes. Finally, Hsp90 clamps around the unfolded kinase β5 strand and interacts with exposed N- and C-lobe interfaces, protecting the kinase in a trapped unfolded state. On the basis of this structure and an extensive amount of previously collected data, we propose unifying conceptual and mechanistic models of chaperone-kinase interactions.
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Affiliation(s)
- Kliment A Verba
- Howard Hughes Medical Institute (HHMI) and the Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA 94158, USA
| | - Ray Yu-Ruei Wang
- Howard Hughes Medical Institute (HHMI) and the Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA 94158, USA
| | - Akihiko Arakawa
- RIKEN Systems and Structural Biology Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Yanxin Liu
- Howard Hughes Medical Institute (HHMI) and the Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA 94158, USA
| | - Mikako Shirouzu
- RIKEN Systems and Structural Biology Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Shigeyuki Yokoyama
- RIKEN Systems and Structural Biology Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
| | - David A Agard
- Howard Hughes Medical Institute (HHMI) and the Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA 94158, USA.
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10
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Yuzefovych Y, Blasczyk R, Huyton T. Oncogenic acidic nuclear phosphoproteins ANP32C/D are novel clients of heat shock protein 90. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:2338-48. [DOI: 10.1016/j.bbamcr.2015.06.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Revised: 06/17/2015] [Accepted: 06/19/2015] [Indexed: 11/27/2022]
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11
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Alternative approaches to Hsp90 modulation for the treatment of cancer. Future Med Chem 2015; 6:1587-605. [PMID: 25367392 DOI: 10.4155/fmc.14.89] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Hsp90 is responsible for the conformational maturation of newly synthesized polypeptides (client proteins) and the re-maturation of denatured proteins via the Hsp90 chaperone cycle. Inhibition of the Hsp90 N-terminus has emerged as a clinically relevant strategy for anticancer chemotherapeutics due to the involvement of clients in a variety of oncogenic pathways. Several immunophilins, co-chaperones and partner proteins are also necessary for Hsp90 chaperoning activity. Alternative strategies to inhibit Hsp90 function include disruption of the C-terminal dimerization domain and the Hsp90 heteroprotein complex. C-terminal inhibitors and Hsp90 co-chaperone disruptors prevent cancer cell proliferation similar to N-terminal inhibitors and destabilize client proteins without induction of heat shock proteins. Herein, current Hsp90 inhibitors, the chaperone cycle, and regulation of this cycle will be discussed.
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12
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Structural characterization of the substrate transfer mechanism in Hsp70/Hsp90 folding machinery mediated by Hop. Nat Commun 2014; 5:5484. [PMID: 25407331 DOI: 10.1038/ncomms6484] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Accepted: 10/06/2014] [Indexed: 01/11/2023] Open
Abstract
In eukarya, chaperones Hsp70 and Hsp90 act coordinately in the folding and maturation of a range of key proteins with the help of several co-chaperones, especially Hop. Although biochemical data define the Hop-mediated Hsp70-Hsp90 substrate transfer mechanism, the intrinsic flexibility of these proteins and the dynamic nature of their complexes have limited the structural studies of this mechanism. Here we generate several complexes in the Hsp70/Hsp90 folding pathway (Hsp90:Hop, Hsp90:Hop:Hsp70 and Hsp90:Hop:Hsp70 with a fragment of the client protein glucocorticoid receptor (GR-LBD)), and determine their 3D structure using electron microscopy techniques. Our results show that one Hop molecule binds to one side of the Hsp90 dimer in both extended and compact conformations, through Hop domain rearrangement that take place when Hsp70 or Hsp70:GR-LBD bind to Hsp90:Hop. The compact conformation of the Hsp90:Hop:Hsp70:GR-LBD complex shows that GR-LBD binds to the side of the Hsp90 dimer opposite the Hop attachment site.
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13
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Shim JS, Rao R, Beebe K, Neckers L, Han I, Nahta R, Liu JO. Selective inhibition of HER2-positive breast cancer cells by the HIV protease inhibitor nelfinavir. J Natl Cancer Inst 2012; 104:1576-90. [PMID: 23042933 DOI: 10.1093/jnci/djs396] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Human epidermal growth factor receptor 2 (HER2)-positive breast cancer is highly aggressive and has higher risk of recurrence than HER2-negative cancer. With few treatment options available, new drug targets specific for HER2-positive breast cancer are needed. METHODS We conducted a pharmacological profiling of seven genotypically distinct breast cancer cell lines using a subset of inhibitors of breast cancer cells from a screen of the Johns Hopkins Drug Library. To identify molecular targets of nelfinavir, identified in the screen as a selective inhibitor of HER2-positive cells, we conducted a genome-wide screen of a haploinsufficiency yeast mutant collection. We evaluated antitumor activity of nelfinavir with xenografts in athymic nude mouse models (n = 4-6 per group) of human breast cancer and repeated mixed-effects regression analysis. All statistical tests were two-sided. RESULTS Pharmacological profiling showed that nelfinavir, an anti-HIV drug, selectively inhibited the growth of HER2-positive breast cancer cells in vitro. A genome-wide screening of haploinsufficiency yeast mutants revealed that nelfinavir inhibited heat shock protein 90 (HSP90) function. Further characterization using proteolytic footprinting experiments indicated that nelfinavir inhibited HSP90 in breast cancer cells through a novel mechanism. In vivo, nelfinavir selectively inhibited the growth of HER2-positive breast cancer cells (tumor volume index of HCC1954 cells on day 29, vehicle vs nelfinavir, mean = 14.42 vs 5.16, difference = 9.25, 95% confidence interval [CI] = 5.93 to 12.56, P < .001; tumor volume index of BT474 cells on day 26, vehicle vs nelfinavir, mean = 2.21 vs 0.90, difference = 1.31, 95% CI = 0.83 to 1.78, P < .001). Moreover, nelfinavir inhibited the growth of trastuzumab- and/or lapatinib-resistant, HER2-positive breast cancer cells in vitro at clinically achievable concentrations. CONCLUSION Nelfinavir was found to be a new class of HSP90 inhibitor and can be brought to HER2-breast cancer treatment trials with the same dosage regimen as that used among HIV patients.
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Affiliation(s)
- Joong Sup Shim
- Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
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14
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Characterization of the interaction of Aha1 with components of the Hsp90 chaperone machine and client proteins. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1823:1092-101. [DOI: 10.1016/j.bbamcr.2012.03.014] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Revised: 03/19/2012] [Accepted: 03/26/2012] [Indexed: 01/30/2023]
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15
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Matts RL, Dixit A, Peterson LB, Sun L, Voruganti S, Kalyanaraman P, Hartson SD, Verkhivker GM, Blagg BSJ. Elucidation of the Hsp90 C-terminal inhibitor binding site. ACS Chem Biol 2011; 6:800-7. [PMID: 21548602 DOI: 10.1021/cb200052x] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The Hsp90 chaperone machine is required for the folding, activation, and/or stabilization of more than 50 proteins directly related to malignant progression. Hsp90 contains small molecule binding sites at both its N- and C-terminal domains; however, limited structural and biochemical data regarding the C-terminal binding site is available. In this report, the small molecule binding site in the Hsp90 C-terminal domain was revealed by protease fingerprinting and photoaffinity labeling utilizing LC-MS/MS. The identified site was characterized by generation of a homology model for hHsp90α using the SAXS open structure of HtpG and docking the bioactive conformation of NB into the generated model. The resulting model for the bioactive conformation of NB bound to Hsp90α is presented herein.
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Affiliation(s)
- Robert L. Matts
- Department of Biochemistry and Molecular Biology, NRC 246, Oklahoma State University, Stillwater, Oklahoma 74078, United States
| | - Anshuman Dixit
- The Center for Bioinformatics, The University of Kansas, 2030 Becker Drive, Lawrence, Kansas 66045, United States
| | - Laura B. Peterson
- Department of Medicinal Chemistry, The University of Kansas, 1251 Wescoe Hall Drive, 4070 Malott, Lawrence, Kansas 66045-7582, United States
| | - Liang Sun
- Department of Biochemistry and Molecular Biology, NRC 246, Oklahoma State University, Stillwater, Oklahoma 74078, United States
| | - Sudhakar Voruganti
- Department of Biochemistry and Molecular Biology, NRC 246, Oklahoma State University, Stillwater, Oklahoma 74078, United States
| | - Palgunan Kalyanaraman
- Department of Biochemistry and Molecular Biology, NRC 246, Oklahoma State University, Stillwater, Oklahoma 74078, United States
| | - Steve D. Hartson
- Department of Biochemistry and Molecular Biology, NRC 246, Oklahoma State University, Stillwater, Oklahoma 74078, United States
| | - Gennady M. Verkhivker
- Department of Pharmacology, University of California, San Diego, 9500 Gilman Dr., La Jolla, California 92093-0636, United States
| | - Brian S. J. Blagg
- Department of Medicinal Chemistry, The University of Kansas, 1251 Wescoe Hall Drive, 4070 Malott, Lawrence, Kansas 66045-7582, United States
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16
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Kemen E, Gardiner A, Schultz-Larsen T, Kemen AC, Balmuth AL, Robert-Seilaniantz A, Bailey K, Holub E, Studholme DJ, MacLean D, Jones JDG. Gene gain and loss during evolution of obligate parasitism in the white rust pathogen of Arabidopsis thaliana. PLoS Biol 2011; 9:e1001094. [PMID: 21750662 PMCID: PMC3130010 DOI: 10.1371/journal.pbio.1001094] [Citation(s) in RCA: 213] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2010] [Accepted: 05/10/2011] [Indexed: 01/21/2023] Open
Abstract
Biotrophic eukaryotic plant pathogens require a living host for their growth and form an intimate haustorial interface with parasitized cells. Evolution to biotrophy occurred independently in fungal rusts and powdery mildews, and in oomycete white rusts and downy mildews. Biotroph evolution and molecular mechanisms of biotrophy are poorly understood. It has been proposed, but not shown, that obligate biotrophy results from (i) reduced selection for maintenance of biosynthetic pathways and (ii) gain of mechanisms to evade host recognition or suppress host defence. Here we use Illumina sequencing to define the genome, transcriptome, and gene models for the obligate biotroph oomycete and Arabidopsis parasite, Albugo laibachii. A. laibachii is a member of the Chromalveolata, which incorporates Heterokonts (containing the oomycetes), Apicomplexa (which includes human parasites like Plasmodium falciparum and Toxoplasma gondii), and four other taxa. From comparisons with other oomycete plant pathogens and other chromalveolates, we reveal independent loss of molybdenum-cofactor-requiring enzymes in downy mildews, white rusts, and the malaria parasite P. falciparum. Biotrophy also requires “effectors” to suppress host defence; we reveal RXLR and Crinkler effectors shared with other oomycetes, and also discover and verify a novel class of effectors, the “CHXCs”, by showing effector delivery and effector functionality. Our findings suggest that evolution to progressively more intimate association between host and parasite results in reduced selection for retention of certain biosynthetic pathways, and particularly reduced selection for retention of molybdopterin-requiring biosynthetic pathways. These mechanisms are not only relevant to plant pathogenic oomycetes but also to human pathogens within the Chromalveolata. Plant pathogens that cannot grow except on their hosts are called obligate biotrophs. How such biotrophy evolves is poorly understood. In this study, we sequenced the genome of the obligate biotroph white rust pathogen (Albugo laibachii, Oomycota) of Arabidopsis. From comparisons with other oomycete plant pathogens, diatoms, and the human pathogen Plasmodium falciparum, we reveal a loss of important metabolic enzymes. We also reveal the appearance of defence-suppressing “effectors”, some carrying motifs known from other oomycete effectors, and discover and experimentally verify a novel class of effectors that share a CHXC motif within 50 amino acids of the signal peptide cleavage site. Obligate biotrophy involves an intimate association within host cells at the haustorial interface (where the parasite penetrates the host cell's cell wall), where nutrients are acquired from the host and effectors are delivered to the host. We found that A. laibachii, like Hyaloperonospora arabidopsidis and Plasmodium falciparum, lacks molybdopterin-requiring biosynthetic pathways, suggesting relaxed selection for retention of, or even selection against, this pathway. We propose that when defence suppression becomes sufficiently effective, hosts become such a reliable source of nutrients that a free-living phase can be lost. These mechanisms leading to obligate biotrophy and host specificity are relevant not only to plant pathogenic oomycetes but also to human pathogens.
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Affiliation(s)
- Eric Kemen
- The Sainsbury Laboratory, Norwich Research Park, Norwich, United Kingdom
| | - Anastasia Gardiner
- The Sainsbury Laboratory, Norwich Research Park, Norwich, United Kingdom
| | | | - Ariane C. Kemen
- The Sainsbury Laboratory, Norwich Research Park, Norwich, United Kingdom
| | - Alexi L. Balmuth
- The Sainsbury Laboratory, Norwich Research Park, Norwich, United Kingdom
- The GenePool, The University of Edinburgh, Edinburgh, United Kingdom
| | | | - Kate Bailey
- The Sainsbury Laboratory, Norwich Research Park, Norwich, United Kingdom
| | - Eric Holub
- School of Life Sciences, University of Warwick, Wellesbourne Campus, United Kingdom
| | | | - Dan MacLean
- The Sainsbury Laboratory, Norwich Research Park, Norwich, United Kingdom
| | - Jonathan D. G. Jones
- The Sainsbury Laboratory, Norwich Research Park, Norwich, United Kingdom
- * E-mail:
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17
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Davenport J, Manjarrez JR, Peterson L, Krumm B, Blagg BSJ, Matts RL. Gambogic acid, a natural product inhibitor of Hsp90. JOURNAL OF NATURAL PRODUCTS 2011; 74:1085-92. [PMID: 21486005 PMCID: PMC3103600 DOI: 10.1021/np200029q] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
A high-throughput screening of natural product libraries identified (-)-gambogic acid (1), a component of the exudate of Garcinia harburyi, as a potential Hsp90 inhibitor, in addition to the known Hsp90 inhibitor celastrol (2). Subsequent testing established that 1 inhibited cell proliferation, brought about the degradation of Hsp90 client proteins in cultured cells, and induced the expression of Hsp70 and Hsp90, which are hallmarks of Hsp90 inhibition. Gambogic acid also disrupted the interaction of Hsp90, Hsp70, and Cdc37 with the heme-regulated eIF2α kinase (HRI, an Hsp90-dependent client) and blocked the maturation of HRI in vitro. Surface plasmon resonance spectroscopy indicated that 1 bound to the N-terminal domain of Hsp90 with a low micromolar Kd, in a manner that was not competitive with the Hsp90 inhibitor geldanamycin (3). Molecular docking experiments supported the posit that 1 binds Hsp90 at a site distinct from Hsp90s ATP binding pocket. The data obtained have firmly established 1 as a novel Hsp90 inhibitor and have provided evidence of a new site that can be targeted for the development of improved Hsp90 inhibitors.
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Affiliation(s)
- Jason Davenport
- Department of Biochemistry and Molecular Biology, 246 Noble Research Center, Oklahoma State University, Stillwater, Oklahoma 74078
| | - Jacob R. Manjarrez
- Department of Biochemistry and Molecular Biology, 246 Noble Research Center, Oklahoma State University, Stillwater, Oklahoma 74078
| | - Laura Peterson
- Department of Medicinal Chemistry, 1251 Wescoe Hall Drive, Malott 4070, The University of Kansas, Lawrence, Kansas 66045
| | - Brian Krumm
- Department of Biochemistry and Molecular Biology, 246 Noble Research Center, Oklahoma State University, Stillwater, Oklahoma 74078
| | - Brian S. J. Blagg
- Department of Medicinal Chemistry, 1251 Wescoe Hall Drive, Malott 4070, The University of Kansas, Lawrence, Kansas 66045
| | - Robert L. Matts
- Department of Biochemistry and Molecular Biology, 246 Noble Research Center, Oklahoma State University, Stillwater, Oklahoma 74078
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18
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Antiproliferative and proapoptotic activity of GUT-70 mediated through potent inhibition of Hsp90 in mantle cell lymphoma. Br J Cancer 2010; 104:91-100. [PMID: 21139584 PMCID: PMC3039813 DOI: 10.1038/sj.bjc.6606007] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Background: Mantle cell lymphoma (MCL) is an aggressive B-cell lymphoma with poor prognosis, requiring novel anticancer strategies. Methods: Mantle cell lymphoma cell lines with known p53 status were treated with GUT-70, a tricyclic coumarin derived from Calophyllum brasiliense, and the biological and biochemical consequences of GUT-70 were studied. Results: GUT-70 markedly reduced cell proliferation/viability through G1 cell cycle arrest and increased apoptosis, with greater sensitivity in mutant (mt)-p53-expressing MCL cells than in wild-type (wt)-p53-bearing cells. Mechanistically, GUT-70 showed binding affinity to heat-shock protein 90 (Hsp90) and ubiquitin-dependent proteasomal degradation of Hsp90 client proteins, including cyclin D1, Raf-1, Akt, and mt-p53. Depletion of constitutively overexpressed cyclin D1 by GUT-70 was accompanied by p27 accumulation and decreased Rb phosphorylation. GUT-70 induced mitochondrial apoptosis with Noxa upregulation and Mcl-1 downregulation in mt-p53 cells, but Mcl-1 accumulation in wt-p53 cells. Noxa and Mcl-1 were coimmunoprecipitated, and activated BAK. Treatment with a combination of GUT-70 and bortezomib or doxorubicin had synergistic antiproliferative effects in MCL cells that were independent of p53 status. Conclusion: GUT-70 has pronounced antiproliferative effects in MCL with mt-p53, a known negative prognostic factor for MCL, through Hsp90 inhibition. These findings suggest that GUT-70 has potential utility for the treatment of MCL.
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19
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A systematic protocol for the characterization of Hsp90 modulators. Bioorg Med Chem 2010; 19:684-92. [PMID: 21129982 DOI: 10.1016/j.bmc.2010.10.029] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2010] [Revised: 10/06/2010] [Accepted: 10/12/2010] [Indexed: 12/17/2022]
Abstract
Several Hsp90 modulators have been identified including the N-terminal ligand geldanamycin (GDA), the C-terminal ligand novobiocin (NB), and the co-chaperone disruptor celastrol. Other Hsp90 modulators elicit a mechanism of action that remains unknown. For example, the natural product gedunin and the synthetic anti-spermatogenic agent H2-gamendazole, recently identified Hsp90 modulators, manifest biological activity through undefined mechanisms. Herein, we report a series of biochemical techniques used to classify such modulators into identifiable categories. Such studies provided evidence that gedunin and H2-gamendazole both modulate Hsp90 via a mechanism similar to celastrol, and unlike NB or GDA.
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20
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Davies AE, Kaplan KB. Hsp90-Sgt1 and Skp1 target human Mis12 complexes to ensure efficient formation of kinetochore-microtubule binding sites. ACTA ACUST UNITED AC 2010; 189:261-74. [PMID: 20404110 PMCID: PMC2856898 DOI: 10.1083/jcb.200910036] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The Hsp90–Sgt1 chaperone and the ubiquitin ligase subunit Skp1 regulate the assembly and turnover of the kinetochore complex Mis12. The formation of functional kinetochores requires the accurate assembly of a large number of protein complexes. The Hsp90–Sgt1 chaperone complex is important for this process; however, its targets are not conserved and its exact contribution to kinetochore assembly is unclear. Here, we show that human Hsp90–Sgt1 interacts with the Mis12 complex, a so-called keystone complex required to assemble a large fraction of the kinetochore. Inhibition of Hsp90 or Sgt1 destabilizes the Mis12 complex and delays proper chromosome alignment due to inefficient formation of microtubule-binding sites. Interestingly, coinhibition of Sgt1 and the SCF subunit, Skp1, increases Mis12 complexes at kinetochores and restores timely chromosome alignment but forms less-robust microtubule-binding sites. We propose that a balance of Mis12 complex assembly and turnover is required for the efficient and accurate assembly of kinetochore–microtubule binding sites. These findings support a novel role for Hsp90–Sgt1 chaperones in ensuring the fidelity of multiprotein complex assembly.
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Affiliation(s)
- Alexander E Davies
- The Section of Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616, USA
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21
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Conde R, Belak ZR, Nair M, O'Carroll RF, Ovsenek N. Modulation of Hsf1 activity by novobiocin and geldanamycin. Biochem Cell Biol 2010; 87:845-51. [PMID: 19935870 DOI: 10.1139/o09-049] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Since Hsp90 is a known modulator of HSF1 activity, we examined the effects of two pharmacological inhibitors of Hsp90, novobiocin and geldanamycin, on HSF1 DNA-binding activity in the Xenopus oocyte model system. Novobiocin exhibits antiproliferative activity in culture cells and interacts with a C-terminal ATP-binding pocket on Hsp90, inhibiting Hsp90 autophosphorylation. Treatment of oocytes with novobiocin followed by heat shock results in a dose-dependent decrease in HSF1 DNA-binding and transcriptional activity. Immunoprecipitation experiments demonstrate novobiocin does not alter HSF1 activity through dissociation of Hsp90 from either monomeric or trimerized HSF1, suggesting that the effect of novobiocin on HSF1 is mediated through alterations in Hsp90 autophosphorylation. Geldanamycin binds the N-terminal ATPase site of Hsp90 and inhibits chaperone activity. Geldanamycin treatment of oocytes resulted in a dose-dependent increase in stability of active HSF1 trimers during submaximal heat shock and a delay in disassembly of trimers during recovery. The results suggest that Hsp90 chaperone activity is required for disassembly of HSF1 trimers. The data obtained with novobiocin suggests the C-terminal ATP-binding activity of Hsp90 is required for the initial steps of HSF1 trimerization, whereas the effects of geldanamycin suggest N-terminal ATPase and chaperone activities are required for disassembly of activated trimers. These data provide important insight into the molecular mechanisms by which pharmacological inhibitors of Hsp90 affect the heat shock response.
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Affiliation(s)
- Renaud Conde
- Department of Anatomy and Cell Biology, College of Medicine, 107 Wiggins Rd., University of Saskatchewan, Saskatoon, SK, S7N 5E5, Canada
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22
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Brandt GEL, Blagg BSJ. Alternate strategies of Hsp90 modulation for the treatment of cancer and other diseases. Curr Top Med Chem 2010; 9:1447-61. [PMID: 19860731 DOI: 10.2174/156802609789895683] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2009] [Accepted: 09/07/2009] [Indexed: 12/13/2022]
Abstract
The 90 kDa heat shock protein (Hsp90) has become a validated target for the development of anti-cancer agents. Several Hsp90 inhibitors are currently under clinical trial investigation for the treatment of cancer. All of these agents inhibit Hsp90's protein folding activity by binding to the N-terminal ATP binding site of the Hsp90 molecular chaperone. Administration of these investigational drugs elicits induction of the heat shock response, or the overexpression of several Hsps, which exhibit antiapoptotic and pro-survival effects that may complicate the application of these inhibitors. To circumvent this issue, alternate mechanisms for Hsp90 inhibition that do not elicit the heat shock response have been identified and pursued. After providing background on the structure, function, and mechanism of the Hsp90 protein folding machinery, this review describes several mechanisms of Hsp90 modulation via small molecules that do not induce the heat shock response.
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Affiliation(s)
- Gary E L Brandt
- Department of Medicinal Chemistry, The University of Kansas, Lawrence, Kansas, 66045-7582, USA
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23
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Echeverria PC, Picard D. Molecular chaperones, essential partners of steroid hormone receptors for activity and mobility. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2009; 1803:641-9. [PMID: 20006655 DOI: 10.1016/j.bbamcr.2009.11.012] [Citation(s) in RCA: 155] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2009] [Revised: 11/18/2009] [Accepted: 11/30/2009] [Indexed: 10/20/2022]
Abstract
Steroid hormone receptors (SHRs) are notorious intracellular travellers, transiting among different cellular compartments as they mature, are subjected to regulation and exert their biological functions. Understanding the processes governing the intracellular traffic of SHRs is important, since their unbalanced or erroneous localization could lead to the development of diseases. In this review, we not only explore the functions of the heat-shock protein 90 (Hsp90) molecular chaperone machine for the intracellular transport of SHRs, but also for the regulation of their nuclear mobility, for their recycling and for the regulation of their transcriptional output.
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Affiliation(s)
- Pablo C Echeverria
- Département de Biologie Cellulaire, Université de Genève, 1211 Genève 4, Switzerland
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24
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Shelton SN, Shawgo ME, Matthews SB, Lu Y, Donnelly AC, Szabla K, Tanol M, Vielhauer GA, Rajewski RA, Matts RL, Blagg BSJ, Robertson JD. KU135, a novel novobiocin-derived C-terminal inhibitor of the 90-kDa heat shock protein, exerts potent antiproliferative effects in human leukemic cells. Mol Pharmacol 2009; 76:1314-22. [PMID: 19741006 DOI: 10.1124/mol.109.058545] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The 90-kDa heat shock protein (Hsp90) assists in the proper folding of numerous mutated or overexpressed signal transduction proteins that are involved in cancer. Consequently, there is considerable interest in developing chemotherapeutic drugs that specifically disrupt the function of Hsp90. Here, we investigated the extent to which a novel novobiocin-derived C-terminal Hsp90 inhibitor, designated KU135, induced antiproliferative effects in Jurkat T-lymphocytes. The results indicated that KU135 bound directly to Hsp90, caused the degradation of known Hsp90 client proteins, and induced more potent antiproliferative effects than the established N-terminal Hsp90 inhibitor 17-allylamino-demethoxygeldanamycin (17-AAG). Closer examination of the cellular response to KU135 and 17-AAG revealed that only 17-AAG induced a strong up-regulation of Hsp70 and Hsp90. In addition, KU135 caused wild-type cells to undergo G(2)/M arrest, whereas cells treated with 17-AAG accumulated in G(1). Furthermore, KU135 but not 17-AAG was found to be a potent inducer of mitochondria-mediated apoptosis as evidenced, in part, by the fact that cell death was inhibited to a similar extent by Bcl-2/Bcl-x(L) overexpression or the depletion of apoptotic protease-activating factor-1 (Apaf-1). Together, these data suggest that KU135 inhibits cell proliferation by regulating signaling pathways that are mechanistically different from those targeted by 17-AAG and as such represents a novel opportunity for Hsp90 inhibition.
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Affiliation(s)
- Shary N Shelton
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS, USA
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25
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Millson SH, Nuttall JM, Mollapour M, Piper PW. The Hsp90/Cdc37p chaperone system is a determinant of molybdate resistance in Saccharomyces cerevisiae. Yeast 2009; 26:339-47. [PMID: 19399909 DOI: 10.1002/yea.1670] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Saccharomyces cerevisiae lacks enzymes that contain the molybdopterin co-factor and therefore any requirement for molybdenum as a trace mineral supplement. Instead, high molybdate levels are inhibitory to its growth. Low cellular levels of heat shock protein 90 (Hsp90), an essential chaperone, were found to enhance this sensitivity to molybdate. Certain Hsp90 point mutations and co-chaperone protein defects that partially compromise the function of the Hsp90/Cdc37p chaperone system also rendered S. cerevisiae hypersensitive to high molybdate levels. Sensitivity was especially apparent with mutations close to the Hsp90 nucleotide binding site, with the loss of the non-essential co-chaperone Sti1p (the equivalent of mammalian Hop), and with the abolition of residue Ser14 phosphorylation on the essential co-chaperone Cdc37p. While it remains to be proved that these effects reflect direct inhibition of the Hsp90 of the cell by the MoO(4) (2+) oxyanion in vivo; this possibility is suggested by molybdate sensitivity arising with a mutation in the Hsp90 nucleotide binding site that does not generate stress sensitivity or an impaired stress response. Molybdate sensitivity may therefore be a useful phenotype to score when studying mutations in this chaperone system.
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Affiliation(s)
- Stefan H Millson
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK
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26
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Lu Y, Ansar S, Michaelis ML, Blagg BSJ. Neuroprotective activity and evaluation of Hsp90 inhibitors in an immortalized neuronal cell line. Bioorg Med Chem 2009; 17:1709-15. [PMID: 19138859 PMCID: PMC2729088 DOI: 10.1016/j.bmc.2008.12.047] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2008] [Revised: 12/17/2008] [Accepted: 12/19/2008] [Indexed: 01/31/2023]
Abstract
Alzheimer's disease (AD) neuropathology is characterized by loss of synapses and neurons, neuritic plaques consisting of beta-amyloid (Abeta) peptides, and neurofibrillary tangles consisting of intracellular aggregates of hyperphosphorylated tau protein in susceptible brain regions. Abeta oligomers trigger a cascade of pathogenic events including tau hyperphosphorylation and aggregation, inflammatory reactions, and excitotoxicity that contribute to the progression of AD. The molecular chaperone Hsp90 facilitates the folding of newly synthesized and denatured proteins and is believed to play a role in neurodegenerative disorders in which the defining pathology results in misfolded proteins and the accumulation of protein aggregates. Some agents that inhibit Hsp90 protect neurons against Abeta toxicity and tau aggregation, and assays for rapidly screening potential Hsp90 inhibitors are of interest. We used the release of the soluble cytosolic enzyme lactate dehydrogenase (LDH) as an indicator of the loss of cell membrane integrity and cytotoxicity resulting from exposure to Abeta peptides to evaluate the neuroprotective properties of novel novobiocin analogues and established Hsp90 inhibitors. Compounds were assessed for potency in protecting proliferating and differentiated SH-SY5Y neuronal cells against Abeta-induced cell death; the potential toxicity of each agent alone was also determined. The data indicated that several of the compounds decreased Abeta toxicity even at low nanomolar concentrations and, unexpectedly, were more potent in protecting the undifferentiated cells against Abeta. The novobiocin analogues alone were not toxic even up to 10 microM concentrations whereas GDA and the parent compound, novobiocin, were toxic at 1 and 10 microM, respectively. The results suggest that novobiocin analogues may provide novel leads for the development of neuroprotective drugs.
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Affiliation(s)
- Yuanming Lu
- The Department of Medicinal Chemistry, The University of Kansas, 1251 Wescoe Hall Drive, Malott 4070, Lawrence, KS 66045-7563 USA
| | - Sabah Ansar
- Department of Pharmacology and Toxicology, The University of Kansas, 1251 Wescoe Hall Drive, Lawrence, KS 66045 USA
| | - Mary L. Michaelis
- Department of Pharmacology and Toxicology, The University of Kansas, 1251 Wescoe Hall Drive, Lawrence, KS 66045 USA
| | - Brian S. J. Blagg
- The Department of Medicinal Chemistry, The University of Kansas, 1251 Wescoe Hall Drive, Malott 4070, Lawrence, KS 66045-7563 USA
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Yin Z, Henry EC, Gasiewicz TA. (-)-Epigallocatechin-3-gallate is a novel Hsp90 inhibitor. Biochemistry 2009; 48:336-45. [PMID: 19113837 DOI: 10.1021/bi801637q] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
(-)-Epigallocatechin-3-gallate (EGCG), a major component of green tea, protects against certain types of cancers, although the mechanism has not yet been determined. It was previously demonstrated that EGCG blocks aryl hydrocarbon receptor (AhR)-mediated transcription induced by the potent carcinogen 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Unlike other AhR antagonists that directly bind to the AhR, EGCG inhibits AhR-mediated transcription by binding to hsp90. We hypothesize that EGCG exerts anti-AhR and anticancer effects by acting as an hsp90 inhibitor. Using proteolytic footprinting, immunoprecipitation, and an ATP-agarose pull-down assay, EGCG was found to directly modulate the conformation of hsp90 and bind at or near to a C-terminal ATP binding site. Hsp90 chaperone function, as assessed by its ability to mediate refolding of denatured luciferase, was inhibited by EGCG treatment. Hsp90 dimerization, which occurs at the C-terminal end, was also inhibited by EGCG treatment. Coimmunoprecipitation studies showed that EGCG stabilizes an AhR complex that includes hsp90 and XAP2 (hepatitis B virus X-associated protein 2), and decreases the association of aryl hydrocarbon nuclear translocator (Arnt) with ligand-activated AhR. Thus, EGCG, through its ability to bind to hsp90, blocks AhR response element (AhRE) recognition. These studies indicate a novel mechanism whereby EGCG inhibits ligand-induced AhRE binding and AhR-mediated transcriptional activity. In EGCG-treated human ovarian carcinoma SKOV3 cells, decreased levels of several cancer-related hsp90 client proteins, such as ErbB2, Raf-1 and phospho-AKT, were observed. EGCG also modified the association of hsp90 with several cochaperones. Overall, these data indicate that EGCG is a novel hsp90 inhibitor. Further studies are needed to determine if this has a role in the antitumor actions of EGCG.
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Affiliation(s)
- Zhengyu Yin
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, New York 14642, USA
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28
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Donnelly A, Blagg BSJ. Novobiocin and additional inhibitors of the Hsp90 C-terminal nucleotide-binding pocket. Curr Med Chem 2008; 15:2702-17. [PMID: 18991631 PMCID: PMC2729083 DOI: 10.2174/092986708786242895] [Citation(s) in RCA: 235] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The 90 kDa heat shock proteins (Hsp90), which are integrally involved in cell signaling, proliferation, and survival, are ubiquitously expressed in cells. Many proteins in tumor cells are dependent upon the Hsp90 protein folding machinery for their stability, refolding, and maturation. Inhibition of Hsp90 uniquely targets client proteins associated with all six hallmarks of cancer. Thus, Hsp90 has emerged as a promising target for the treatment of cancer. Hsp90 exists as a homodimer, which contains three domains. The N-terminal domain contains an ATP-binding site that binds the natural products geldanamycin and radicicol. The middle domain is highly charged and has high affinity for co-chaperones and client proteins. Initial studies by Csermely and co-workers suggested a second ATP-binding site in the C-terminus of Hsp90. This C-terminal nucleotide binding pocket has been shown to not only bind ATP, but cisplatin, novobiocin, epilgallocatechin-3-gallate (EGCG) and taxol. The coumarin antibiotics novobiocin, clorobiocin, and coumermycin A1 were isolated from several streptomyces strains and exhibit potent activity against Gram-positive bacteria. These compounds bind type II topoisomerases, including DNA gyrase, and inhibit the enzyme-catalyzed hydrolysis of ATP. As a result, novobiocin analogues have garnered the attention of numerous researchers as an attractive agent for the treatment of bacterial infection. Novobiocin was reported to bind weakly to the newly discovered Hsp90 C-terminal ATP binding site ( approximately 700 M in SkBr3 cells) and induce degradation of Hsp90 client proteins. Structural modification of this compound has led to an increase of 1000-fold in activity in anti-proliferative assays. Recent studies of structure-activity relationship (SAR) by Renoir and co-workers highlighted the crucial role of the C-4 and/or C-7 positions of the coumarin and removal of the noviose moiety, which appeared to be essential for degradation of Hsp90 client proteins. Unlike the N-terminal ATP binding site, there is no reported co-crystal structure of Hsp90 C-terminus bound to any inhibitor. The Hsp90 C-terminal domain, however, is known to contain a conserved pentapeptide sequence (MEEVD) which is recognized by co-chaperones. Cisplatin is a platinum-containing chemotherapeutic used to treat various types of cancers, including testicular, ovarian, bladder, and small cell lung cancer. Most notably, cisplatin coordinates to DNA bases, resulting in cross-linked DNA, which prohibits rapidly dividing cells from duplicating DNA for mitosis. Itoh and co-workers reported that cisplatin decreases the chaperone activity of Hsp90. This group applied bovine brain cytosol to a cisplatin affinity column, eluted with cisplatin and detected Hsp90 in the eluent. Subsequent experiments indicated that cisplatin exhibits high affinity for Hsp90. Moreover Csermely and co-workers determined that the cisplatin binding site is located proximal to the C-terminal ATP binding site. EGCG is one of the active ingredients found in green tea. EGCG is known to inhibit the activity of many Hsp90-dependent client proteins, including telomerase, several kinases, and the aryl hydrocarbon receptor (AhR). Recently Gasiewicz and co-workers reported that EGCG manifests its antagonistic activity against AhR through binding Hsp90. Similar to novobiocin, EGCG was shown to bind the C-terminus of Hsp90. Unlike previously identified N-terminal Hsp90 inhibitors, EGCG does not appear to prevent Hsp90 from forming multiprotein complexes. Studies are currently underway to determine whether EGCG competes with novobiocin or cisplatin binding. Taxol, a well-known drug for the treatment of cancer, is responsible for the stabilization of microtubules and the inhibition of mitosis. Previous studies have shown that taxol induces the activation of kinases and transcription factors, and mimics the effect of bacterial lipopolysaccharide (LPS), an attribute unrelated to its tubulin-binding properties. Rosen and co-workers prepared a biotinylated taxol derivative and performed affinity chromatography experiments with lysates from both mouse brain and macrophage cell lines. These studies led to identification of two chaperones, Hsp70 and Hsp90, by mass spectrometry. In contrast to typical Hsp90-binding drugs, taxol exhibits a stimulatory response. Recently it was reported that the geldanamycin derivative 17-AAG behaves synergistically with taxol-induced apoptosis. This review describes the different C-terminal inhibitors of Hsp90, with specific emphasis on structure-activity relationship studies of novobiocin and their effects on anti-proliferative activity.
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Affiliation(s)
- Alison Donnelly
- Department of Medicinal Chemistry, 1251 Wescoe Hall Drive, Malott 4070, The University of Kansas, Lawrence, Kansas 66045-7563, USA
| | - Brian S. J. Blagg
- Department of Medicinal Chemistry, 1251 Wescoe Hall Drive, Malott 4070, The University of Kansas, Lawrence, Kansas 66045-7563, USA
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29
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Hadden MK, Galam L, Gestwicki JE, Matts RL, Blagg BSJ. Derrubone, an inhibitor of the Hsp90 protein folding machinery. JOURNAL OF NATURAL PRODUCTS 2007; 70:2014-2018. [PMID: 18020309 DOI: 10.1021/np070190s] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
High-throughput screening of a library of diverse molecules has identified derrubone ( 1), an isoflavone natural product from Derris robusta, as a potent Hsp90 inhibitor. Subsequent testing in several cellular-based assays established 1 as a low micromolar inhibitor in vitro. In addition, derrubone induced the degradation of numerous Hsp90 client proteins, a hallmark effect resulting from Hsp90 inhibition. The identification of 1 as an Hsp90 inhibitor provides a new natural product scaffold upon which the development of novel Hsp90 inhibitors can be pursued.
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Affiliation(s)
- M Kyle Hadden
- Department of Medicinal Chemistry, Malott 4070, The University of Kansas, Lawrence, KS 66045-7563, USA
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30
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Hardcastle A, Tomlin P, Norris C, Richards J, Cordwell M, Boxall K, Rowlands M, Jones K, Collins I, McDonald E, Workman P, Aherne W. A duplexed phenotypic screen for the simultaneous detection of inhibitors of the molecular chaperone heat shock protein 90 and modulators of cellular acetylation. Mol Cancer Ther 2007; 6:1112-22. [PMID: 17363504 DOI: 10.1158/1535-7163.mct-06-0496] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Histone deacetylases (HDACs), histone acetyltransferases (HATs), and the molecular chaperone heat shock protein 90 (HSP90) are attractive anticancer drug targets. High-throughput screening plays a pivotal role in modern molecular mechanism-based drug discovery. Cell-based screens are particularly useful in that they identify compounds that are permeable and active against the selected target or pathway in a cellular context. We have previously developed time-resolved fluorescence cell immunosorbent assays (TRF-Cellisas) for compound screening and pharmacodynamic studies. These assays use a primary antibody to the single protein of interest and a matched secondary immunoglobulin labeled with an europium chelate (Eu). The availability of species-specific secondary antibodies labeled with different lanthanide chelates provides the potential for multiplexing this type of assay. The approach has been applied to the development of a 384-well duplexed cell-based screen to simultaneously detect compounds that induce the co-chaperone HSP70 as a molecular marker of potential inhibitors of HSP90 together with those that modulate cellular acetylation (i.e., potential inhibitors of histone deacetylase or histone acetyltransferase activity). The duplexed assay proved reliable in high-throughput format and approximately 64,000 compounds were screened. Following evaluation in secondary assays, 3 of 13 hits from the HSP70 arm were confirmed. Two of these directly inhibited the intrinsic ATPase activity of HSP90 whereas the third seems to have a different mechanism of action. In the acetylation arm, two compounds increased cellular acetylation, one of which inhibited histone deacetylase activity. A third compound decreased cellular histone acetylation, potentially through a novel mechanism of action.
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Affiliation(s)
- Anthea Hardcastle
- Cancer Research UK Centre for Cancer Therapeutics, The Institute of Cancer Research, Haddow Laboratories, 15 Cotswold Road, Sutton, Surrey SM2 5NG, United Kingdom
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31
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Te J, Jia L, Rogers J, Miller A, Hartson SD. Novel subunits of the mammalian Hsp90 signal transduction chaperone. J Proteome Res 2007; 6:1963-73. [PMID: 17348703 DOI: 10.1021/pr060595i] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
As one of the major cellular chaperones, Hsp90 plays diverse roles in supporting and regulating wild-type and oncogenic signal transduction proteins. Hsp90 function itself is regulated by its various nonsubstrate subunits. To define Hsp90's predominant in vivo functions and the mechanisms for regulating this function, the human Hsp90 interactome was characterized using gel-based proteomics techniques. Results show that Hsp90's most prominent association is its previously described interaction with Hsp70, a primary chaperone capable of recognizing and binding hydrophobic peptide segments. Additionally, novel human proteins discovered in this study reveal that several newly described Hsp90 associations in yeast are conserved in the human cytoplasm. Additionally, other new Hsp90 subunits imply that a great deal of Hsp90 function may be directed to the assembly, regulation, or exploitation of the tubulin-based cytoskeleton network, particularly the mitotic spindle.
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Affiliation(s)
- Jeannie Te
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, Oklahoma 74078-3035, USA
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32
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Galam L, Hadden MK, Ma Z, Ye Q, Yun BG, Blagg BSJ, Matts RL. High-throughput assay for the identification of Hsp90 inhibitors based on Hsp90-dependent refolding of firefly luciferase. Bioorg Med Chem 2007; 15:1939-46. [PMID: 17223347 PMCID: PMC1906718 DOI: 10.1016/j.bmc.2007.01.004] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2006] [Revised: 12/20/2006] [Accepted: 01/01/2007] [Indexed: 10/23/2022]
Abstract
Previously, we have demonstrated that the renaturation of heat denatured firefly luciferase is dependent upon the activity of Hsp90 in rabbit reticulocyte lysate. Here, we demonstrate that this assay may identify inhibitors that obstruct the chaperone activity of Hsp90 either by direct binding to its N-terminal or C-terminal nucleotide binding sites or by interference with the ability of the chaperone to switch conformations. The assay was adapted and optimized for high-throughput screening. Greater than 20,000 compounds were screened to demonstrate the feasibility of using this assay on a large scale. The assay was reproducible (av Z-factor=0.62) and identified 120 compounds that inhibited luciferase renaturation by greater than 70% at a concentration of 12.5 microg/mL. IC50 values for twenty compounds with varying structures were determined for inhibition of luciferase refolding and in cell-based assays for Hsp90 inhibition. Several compounds had IC50 values <10 microM and represent a number of new lead structures with the potential for further development and optimization as potent Hsp90 inhibitors.
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Affiliation(s)
- Lakshmi Galam
- Department of Biochemistry and Molecular Biology, NRC 246, Oklahoma State University, Stillwater, Oklahoma, U.S.A. 74078
| | - M. Kyle Hadden
- Department of Medicinal Chemistry, 1251 Wescoe Hall Drive, Malott 4070, The University of Kansas, Lawrence, Kansas, U.S.A. 66045-7563
| | - Zeqiang Ma
- High-Throughput Screening Laboratory, The University of Kansas, 1501 Wakarusa Drive, Lawrence, Kansas, U.S.A. 66047
| | - Qi–Zhuang Ye
- High-Throughput Screening Laboratory, The University of Kansas, 1501 Wakarusa Drive, Lawrence, Kansas, U.S.A. 66047
| | - Bo-Geon Yun
- Department of Biochemistry and Molecular Biology, NRC 246, Oklahoma State University, Stillwater, Oklahoma, U.S.A. 74078
| | - Brian S. J. Blagg
- Department of Medicinal Chemistry, 1251 Wescoe Hall Drive, Malott 4070, The University of Kansas, Lawrence, Kansas, U.S.A. 66045-7563
| | - Robert L. Matts
- Department of Biochemistry and Molecular Biology, NRC 246, Oklahoma State University, Stillwater, Oklahoma, U.S.A. 74078
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33
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Scroggins BT, Robzyk K, Wang D, Marcu MG, Tsutsumi S, Beebe K, Cotter RJ, Felts S, Toft D, Karnitz L, Rosen N, Neckers L. An acetylation site in the middle domain of Hsp90 regulates chaperone function. Mol Cell 2007; 25:151-9. [PMID: 17218278 PMCID: PMC1839984 DOI: 10.1016/j.molcel.2006.12.008] [Citation(s) in RCA: 327] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2006] [Revised: 11/01/2006] [Accepted: 12/12/2006] [Indexed: 12/21/2022]
Abstract
Heat-shock protein 90 (Hsp90) chaperones a key subset of signaling proteins and is necessary for malignant transformation. Hsp90 is subject to an array of posttranslational modifications that affect its function, including acetylation. Histone deacetylase (HDAC) inhibitors and knockdown of HDAC6 induce Hsp90 acetylation and inhibit its activity. However, direct determination of the functional consequences of Hsp90 acetylation has awaited mapping of specific sites. We now demonstrate that Hsp90 K294 is acetylated. Mutational analysis of K294 shows that its acetylation status is a strong determinant of client protein and cochaperone binding. In yeast, Hsp90 mutants that cannot be acetylated at K294 have reduced viability and chaperone function compared to WT or to mutants that mimic constitutive acetylation. These data suggest that acetylation/deacetylation of K294 plays an important role in regulating the Hsp90 chaperone cycle.
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Affiliation(s)
- Bradley T Scroggins
- Urologic Oncology Branch, National Cancer Institute, Bethesda, MD 20892, USA
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34
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Blagg BSJ, Kerr TD. Hsp90 inhibitors: small molecules that transform the Hsp90 protein folding machinery into a catalyst for protein degradation. Med Res Rev 2006; 26:310-38. [PMID: 16385472 DOI: 10.1002/med.20052] [Citation(s) in RCA: 142] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The 90 kDa heat shock proteins (Hsp90) are responsible for the conformational maturation of nascent polypeptides and the renaturation of denatured proteins. In transformed cells, numerous mutated and overexpressed proteins rely on the Hsp90 protein folding machinery for tumor progression. The Hsp90-mediated protein folding process is dependent upon ATP, and when inhibitors of ATP are present, the Hsp90 machinery is unable to fold client proteins into their biologically active form, which results in the degradation of protein substrates via the ubiquitin-proteasome pathway. Consequently, Hsp90 has evolved into a promising anti-cancer target because multiple oncogenic proteins can be simultaneously degraded as a consequence of Hsp90 inhibition. This review serves to explain the Hsp90 protein folding process, the impact of Hsp90 inhibition, the identification of natural product inhibitors, and the development of rationally designed inhibitors of the Hsp90 protein folding machinery.
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Affiliation(s)
- Brian S J Blagg
- The Department of Medicinal Chemistry, The University of Kansas, Lawrence, 66045, USA.
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35
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Stricker SA, Smythe TL. Differing mechanisms of cAMP- versus seawater-induced oocyte maturation in marine nemertean worms II. The roles of tyrosine kinases and phosphatases. Mol Reprod Dev 2006; 73:1564-77. [PMID: 16902949 DOI: 10.1002/mrd.20596] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Instead of blocking oocyte maturation as it does in most animals, cAMP causes oocytes of marine nemertean worms to initiate maturation (=germinal vesicle breakdown, "GVBD"). To characterize cAMP-induced GVBD in nemerteans, inhibitors of tyrosine kinase signaling were tested on Cerebratulus sp. oocytes that had been incubated in cAMP-elevating drugs versus seawater (SW) alone. Such tests yielded similar results for Src-like tyrosine kinase blockers, as the inhibitors prevented mitogen-activated protein kinase (MAPK) activation without stopping either GVBD or maturation-promoting factor (MPF) activation in both SW and cAMP-elevating treatments. Alternatively, genistein, a general tyrosine kinase antagonist, and piceatannol, an inhibitor of the tyrosine kinase Syk, reduced GVBD and MAPK/MPF activities in SW-, but not cAMP-induced maturation. Similarly, inhibitors of the human epidermal growth factor receptor-2 (HER-2) tyrosine kinase prevented GVBD and MAPK/MPF activations in oocytes treated with SW, but not with cAMP-elevating drugs. Antagonists of either protein tyrosine phosphatases (PTPs) or the dual-specificity phosphatase Cdc25 also reduced GVBD and MAPK/MPF activities in SW-treated oocytes without generally affecting cAMP-induced maturation. Collectively, these data suggest cAMP triggers GVBD via pathways that do not require MAPK activation or several components of tyrosine kinase signaling. In addition, such differences in tyrosine kinase cascades, coupled with the dissimilar patterns of Ser/Thr kinase signaling described in the accompanying study, indicate that nemertean oocytes are capable of utilizing multiple mechanisms to activate MPF during GVBD.
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Affiliation(s)
- Stephen A Stricker
- Department of Biology, University of New Mexcio, Albuquerque, 87131, USA.
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36
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Prince T, Shao J, Matts RL, Hartson SD. Evidence for chaperone heterocomplexes containing both Hsp90 and VCP. Biochem Biophys Res Commun 2005; 331:1331-7. [PMID: 15883021 DOI: 10.1016/j.bbrc.2005.04.047] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2005] [Indexed: 12/27/2022]
Abstract
With assistance from co-chaperone partner proteins, Hsp90 plays an essential positive role in supporting the structure and function of numerous client proteins in vivo. Hsp90's co-chaperone partnerships are believed to regulate and/or target its function. Here we describe associations between Hsp90 chaperone machinery and another chaperone, the 97-kDa valosin-containing protein VCP. Coimmunoadsorption assays indicate that VCP occurs in one or more native heterocomplexes containing Hsp90 and the Hsp90 partner proteins Cdc37, FKBP52, and p23. Functional characterizations indicate that VCP is not an Hsp90 substrate, but rather demonstrate the biochemical hallmarks of an Hsp90 co-chaperone. Potential roles for a collaboration between for Hsp90 and VCP are discussed.
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Affiliation(s)
- Thomas Prince
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078-3035, USA
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37
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Prince T, Matts RL. Definition of Protein Kinase Sequence Motifs That Trigger High Affinity Binding of Hsp90 and Cdc37. J Biol Chem 2004; 279:39975-81. [PMID: 15258137 DOI: 10.1074/jbc.m406882200] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Hsp90 cooperates with its co-chaperone Cdc37 to provide obligatory support to numerous protein kinases involved in the regulation of cellular signal transduction pathways. In this report, the crystal structure of the Src family tyrosine kinase Lck was used to guide the creation of kinase constructs to determine features recognized by Hsp90 and its "kinase-specific" co-chaperone Cdc37. Two parameters were assayed: the ability and extent to which the constructs bound to Hsp90 and Cdc37, and the ability of the constructs to trigger salt-resistant high affinity complexes with Hsp90 and Cdc37 independent of the presence of molybdate. Although Hsp90 interacted with both the N-terminal and C-terminal lobes (NL and CL, respectively) of the catalytic domains of the kinases, the lobes themselves were not sufficient to trigger the high affinity binding of Hsp90. Only constructs containing a complete N- or C-terminal lobe and part of the adjacent lobe bound to Hsp90 and Cdc37 in salt-stable complexes independent of molybdate. The two minimum constructs that bound Hsp90 and Cdc37 contained the alpha-C-helix and the beta4- and beta5-strands of the NL through to end of the CL and the NL through to the alpha-E-helix and the amino acids that cap the helix. Cdc37 interacted with only the NL and minimally required the alpha-C-helix and beta4- and beta5-strands of this lobe of Lck. The results indicate that the high affinity binding activity of Hsp90 is triggered through its interaction with adjacent subdomain structures of kinase catalytic domains. Furthermore, the alpha-C-helix and part of its adjoining loop connection to the beta4-strand appear to be the primary determinants recognized by Cdc37.
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Affiliation(s)
- Thomas Prince
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, Oklahoma 74078-3035, USA
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38
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Harris SF, Shiau AK, Agard DA. The crystal structure of the carboxy-terminal dimerization domain of htpG, the Escherichia coli Hsp90, reveals a potential substrate binding site. Structure 2004; 12:1087-97. [PMID: 15274928 DOI: 10.1016/j.str.2004.03.020] [Citation(s) in RCA: 142] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2004] [Revised: 03/17/2004] [Accepted: 03/21/2004] [Indexed: 11/27/2022]
Abstract
Hsp90 is a ubiquitous, well-conserved molecular chaperone involved in the folding and stabilization of diverse proteins. Beyond its capacity for general protein folding, Hsp90 influences a wide array of cellular signaling pathways that underlie key biological and disease processes. It has been proposed that Hsp90 functions as a molecular clamp, dimerizing through its carboxy-terminal domain and utilizing ATP binding and hydrolysis to drive large conformational changes including transient dimerization of the amino-terminal and middle domains. We have determined the 2.6 A X-ray crystal structure of the carboxy-terminal domain of htpG, the Escherichia coli Hsp90. This structure reveals a novel fold and that dimerization is dependent upon the formation of a four-helix bundle. Remarkably, proximal to the helical dimerization motif, each monomer projects a short helix into solvent. The location, flexibility, and amphipathic character of this helix suggests that it may play a role in substrate binding and hence chaperone activity.
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Affiliation(s)
- Seth F Harris
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94143, USA
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39
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Botos J, Xian W, Smith DF, Smith CL. Progesterone receptor deficient in chromatin binding has an altered cellular state. J Biol Chem 2004; 279:15231-9. [PMID: 14744870 DOI: 10.1074/jbc.m309718200] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Our previous work has shown that the progesterone receptor (PR) can exist in two distinct functional states in mammary adenocarcinoma cells. The differences in function included the ability to activate a promoter in organized chromatin, sensitivity to ligand, and ligand-independent activation. To determine whether these functional differences were because of altered cellular processing, we carried out biochemical analyses of the functionally distinct PRs. Although the majority of PR is localized to the nucleus, biochemical partitioning resulted in a loosely bound (cytosolic) fraction, and a tightly bound (nuclear) fraction. In the absence of progestins, the functionally distinct PRs differed significantly in partitioning between the two fractions. To characterize these fractions further, we analyzed interactions of unliganded PR with chaperones by coimmunoprecipitation. We determined that PR in the cytosolic fraction associated with hsp90 and p23. In contrast, PR in the nuclear fraction consisted of complexes containing hsp90, p23, and FKBP51 as well as PR that was dimerized and highly phosphorylated. Hormone treatment significantly reduced the formation of all PR-chaperone complexes. The hsp90 inhibitor, geldanamycin, similarly blocked transcriptional activity of both functionally distinct receptors. However, the two forms of the PR differed in their ability to associate with the mouse mammary tumor virus promoter in organized chromatin. These findings provide new information about the composition and distribution of mature progesterone receptor complexes in mammary adenocarcinoma cells, and suggest that differences in receptor subcellular distribution have a significant impact on their function. These findings also reveal that transiently expressed steroid receptors may not always be processed like their endogenous counterparts.
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MESH Headings
- Animals
- Benzoquinones
- Blotting, Western
- Cell Line, Tumor
- Cell Nucleus/metabolism
- Chromatin/chemistry
- Chromatin/metabolism
- Cytosol/metabolism
- DNA/chemistry
- DNA/metabolism
- Dimerization
- Dose-Response Relationship, Drug
- Enzyme Inhibitors/pharmacology
- Fluorescent Antibody Technique, Indirect
- Genes, Viral
- HSP90 Heat-Shock Proteins/metabolism
- Hormones/metabolism
- In Situ Hybridization, Fluorescence
- Intramolecular Oxidoreductases
- Lactams, Macrocyclic
- Ligands
- Luciferases/metabolism
- Mammary Tumor Virus, Mouse/genetics
- Mice
- Microscopy, Fluorescence
- Models, Biological
- Molecular Chaperones/metabolism
- Phosphoproteins/metabolism
- Phosphorylation
- Precipitin Tests
- Promoter Regions, Genetic
- Prostaglandin-E Synthases
- Protein Binding
- Protein Conformation
- Quinones/pharmacology
- Receptors, Progesterone/chemistry
- Receptors, Progesterone/metabolism
- Tacrolimus Binding Proteins/chemistry
- Tacrolimus Binding Proteins/metabolism
- Transcription, Genetic
- Transfection
- beta-Galactosidase/metabolism
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Affiliation(s)
- Jeannine Botos
- Laboratory of Receptor Biology and Gene Expression, NCI, National Institutes of Health, Bethesda, Maryland 20892-5055, USA.
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40
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Shao J, Prince T, Hartson SD, Matts RL. Phosphorylation of serine 13 is required for the proper function of the Hsp90 co-chaperone, Cdc37. J Biol Chem 2003; 278:38117-20. [PMID: 12930845 DOI: 10.1074/jbc.c300330200] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Hsp90 co-chaperone Cdc37 provides an essential function for the biogenesis and support of numerous protein kinases. In this report, we demonstrate that mammalian Cdc37 is phosphorylated on Ser13 in situ in rabbit reticulocyte lysate and in cultured K562 cells and that casein kinase II is capable of quantitatively phosphorylating recombinant Cdc37 at this site. Mutation of Ser13 to either Ala or Glu compromises the recruitment of Cdc37 to Hsp90-kinase complexes but has only modest effects on its basal (client-free) binding to Hsp90. Furthermore, Cdc37 containing the complementing Ser to Glu mutation showed altered interactions with Hsp90-kinase complexes consistent with compromised Cdc37 modulation of the Hsp90 ATP-driven reaction cycle. Thus, the data indicate that phosphorylation of Cdc37 on Ser13 is critical for its ability to coordinate Hsp90 nucleotide-mediated conformational switching and kinase binding.
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Affiliation(s)
- Jieya Shao
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, Oklahoma 74078-3035, USA
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Hargreaves R, David CL, Whitesell L, Skibo EB. Design of quinolinedione-based geldanamycin analogues. Bioorg Med Chem Lett 2003; 13:3075-8. [PMID: 12941337 DOI: 10.1016/s0960-894x(03)00650-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Quinoline-5,8-dione-based compounds were designed from the structure of the geldanamycin-bound Hsp-90 active site. The active site model predicted that aromatic substituents should be present at the 2-position, to take advantage of a hydrophobic pocket, and amino substituents should be present at the 6- or 7-position. COMPARE analysis revealed that the LC(50) profile of 2-phenyl-6-(2-chloroethylamino)quinoline-5,8-dione has the highest geldanamycin-like activity (0.74 correlation coefficient).
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Affiliation(s)
- Robert Hargreaves
- Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287-1604, USA
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42
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Pratt WB, Toft DO. Regulation of signaling protein function and trafficking by the hsp90/hsp70-based chaperone machinery. Exp Biol Med (Maywood) 2003; 228:111-33. [PMID: 12563018 DOI: 10.1177/153537020322800201] [Citation(s) in RCA: 1060] [Impact Index Per Article: 50.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Nearly 100 proteins are known to be regulated by hsp90. Most of these substrates or "client proteins" are involved in signal transduction, and they are brought into complex with hsp90 by a multiprotein hsp90/hsp70-based chaperone machinery. In addition to binding substrate proteins at the chaperone site(s), hsp90 binds cofactors at other sites that are part of the heterocomplex assembly machinery as well as immunophilins that connect assembled substrate*hsp90 complexes to protein-trafficking systems. In the 5 years since we last reviewed this subject, much has been learned about hsp90 structure, nucleotide-binding, and cochaperone interactions; the most important concept is that ATP hydrolysis by an intrinsic ATPase activity results in a conformational change in hsp90 that is required to induce conformational change in a substrate protein. The conformational change induced in steroid receptors is an opening of the steroid-binding cleft so that it can be accessed by steroid. We have now developed a minimal system of five purified proteins-hsp90, hsp70, Hop, hsp40, and p23- that assembles stable receptor*hsp90 heterocomplexes. An hsp90*Hop*hsp70*hsp40 complex opens the cleft in an ATP-dependent process to produce a receptor*hsp90 heterocomplex with hsp90 in its ATP-bound conformation, and p23 then interacts with the hsp90 to stabilize the complex. Stepwise assembly experiments have shown that hsp70 and hsp40 first interact with the receptor in an ATP-dependent reaction to produce a receptor*hsp70*hsp40 complex that is "primed" to be activated to the steroid-binding state in a second ATP-dependent step with hsp90, Hop, and p23. Successful use of the five-protein system with other substrates indicates that it can assemble signal protein*hsp90 heterocomplexes whether the substrate is a receptor, a protein kinase, or a transcription factor. This purified system should facilitate understanding of how eukaryotic hsp70 and hsp90 work together as essential components of a process that alters the conformations of substrate proteins to states that respond in signal transduction.
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Affiliation(s)
- William B Pratt
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, Michigan 48109-0632, USA
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Yamada SI, Ono T, Mizuno A, Nemoto TK. A hydrophobic segment within the C-terminal domain is essential for both client-binding and dimer formation of the HSP90-family molecular chaperone. EUROPEAN JOURNAL OF BIOCHEMISTRY 2003; 270:146-54. [PMID: 12492485 DOI: 10.1046/j.1432-1033.2003.03375.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The alpha isoform of human 90-kDa heat shock protein (HSP90alpha) is composed of three domains: the N-terminal (residues 1-400); middle (residues 401-615) and C-terminal (residues 621-732). The middle domain is simultaneously associated with the N- and C-terminal domains, and the interaction with the latter mediates the dimeric configuration of HSP90. Besides one in the N-terminal domain, an additional client-binding site exists in the C-terminal domain of HSP90. The aim of the present study is to elucidate the regions within the C-terminal domain responsible for the bindings to the middle domain and to a client protein, and to define the relationship between the two functions. A bacterial two-hybrid system revealed that residues 650-697 of HSP90alpha were essential for the binding to the middle domain. An almost identical region (residues 657-720) was required for the suppression of heat-induced aggregation of citrate synthase, a model client protein. Replacement of either Leu665-Leu666 or Leu671-Leu672 to Ser-Ser within the hydrophobic segment (residues 662-678) of the C-terminal domain caused the loss of bindings to both the middle domain and the client protein. The interaction between the middle and C-terminal domains was also found in human 94-kDa glucose-regulated protein. Moreover, Escherichia coli HtpG, a bacterial HSP90 homologue, formed heterodimeric complexes with HSP90alpha and the 94-kDa glucose-regulated protein through their middle-C-terminal domains. Taken together, it is concluded that the identical region including the hydrophobic segment of the C-terminal domain is essential for both the client binding and dimer formation of the HSP90-family molecular chaperone and that the dimeric configuration appears to be similar in the HSP90-family proteins.
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Affiliation(s)
- Shin-ichi Yamada
- Division of Oral and Maxillofacial Surgery and Division of Oral Molecular Biology, Department of Developmental and Reconstructive Medicine, Course of Medical and Dental Sciences, Nagasaki University Graduate School of Biomedical Sciences, Japan
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44
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Abstract
The chaperoning activity of the heat shock protein hsp90 is directed, in part, by the binding and hydrolysis of ATP and also by association with co-chaperone proteins. One co-chaperone, p23, binds to hsp90 only when hsp90 is in a conformation induced by the binding of ATP. Once formed, the p23-hsp90 complex is very stable upon the removal of ATP and dissipates at 30 degrees with a half-life of about 45 min. This was shown to be due to the high stability of the ATP-induced state of hsp90, not to the rate of p23 dissociation. Further stabilization of this ATP-induced state is achieved by including molybdate or by use of the ATP analogue ATPgammaS. This conformational state of hsp90 is correlated with the tight binding of ADP resulting from hydrolysis of bound ATP. Both p23 and molybdate enhance and stabilize the nucleotide-bound state of hsp90, and this state is maximized by the presence of both agents. These results can be explained in a model where the binding of ATP induces a conformational transition in hsp90 that traps the nucleotide and is committed to ATP hydrolysis. p23 specifically recognizes this state and may also facilitate subsequent steps in the chaperoning cycle.
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Affiliation(s)
- William P Sullivan
- Department of Biochemistry and Molecular Biology, Mayo Graduate School, Mayo Clinic, Rochester, Minnesota 55905, USA
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Söti C, Rácz A, Csermely P. A Nucleotide-dependent molecular switch controls ATP binding at the C-terminal domain of Hsp90. N-terminal nucleotide binding unmasks a C-terminal binding pocket. J Biol Chem 2002; 277:7066-75. [PMID: 11751878 DOI: 10.1074/jbc.m105568200] [Citation(s) in RCA: 170] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In vivo function of the molecular chaperone Hsp90 is ATP-dependent and requires the full-length protein. Our earlier studies predicted a second C-terminal ATP-binding site in Hsp90. By applying direct biochemical approaches, we mapped two ATP-binding sites and unveiled the C-terminal ATP-binding site as the first example of a cryptic chaperone nucleotide-binding site, which is opened by occupancy of the N-terminal site. We identified an N-terminal gamma-phosphate-binding motif in the middle domain of Hsp90 similar to other GHKL family members. This motif is adjacent to the phosphate-binding region of the C-terminal ATP-binding site. Whereas novobiocin disrupts both C- and N-terminal nucleotide binding, we found a selective C-terminal nucleotide competitor, cisplatin, that strengthens the Hsp90-Hsp70 complex leaving the Hsp90-p23 complex intact. Cisplatin may provide a pharmacological tool to dissect C- and N-terminal nucleotide binding of Hsp90. A model is proposed on the interactions of the two nucleotide-binding domains and the charged region of Hsp90.
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Affiliation(s)
- Csaba Söti
- Department of Medical Chemistry, Semmelweis University, P. O. Box 260, Budapest H-1444, Hungary
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Rosenhagen MC, Young JC, Wochnik GM, Herr AS, Schmidt U, Hartl FU, Holsboer F, Rein T. Synergistic inhibition of the glucocorticoid receptor by radicicol and benzoquinone ansamycins. Biol Chem 2001; 382:499-504. [PMID: 11347901 DOI: 10.1515/bc.2001.063] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Radicicol (RAD) and the benzoquinone ansamycin geldanamycin (GA) are potential anticancer drugs known to inhibit heat shock protein 90 (hsp90) and, therefore, the activation of proteins dependent on its function such as proto-oncogenic kinases and nuclear receptors. Using the glucocorticoid receptor (GR) as a model system we analysed the effects of RAD and various benzoquinone ansamycins. All compounds efficiently abolished GR-dependent transactivation. Surprisingly, whenever one of the ansamycins was applied in combination with RAD, synergistic inhibition of GR-dependent transcription and of hormone binding of GR was observed. In contrast, combination of two ansamycins showed no synergy. These findings suggest synergism within the hsp90 dimer and may open new ways to explore hsp90 as therapeutic target.
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Bouhouche-Chatelier L, Chadli A, Catelli MG. The N-terminal adenosine triphosphate binding domain of Hsp90 is necessary and sufficient for interaction with estrogen receptor. Cell Stress Chaperones 2001; 6:297-305. [PMID: 11795466 PMCID: PMC434412 DOI: 10.1379/1466-1268(2001)006<0297:tntatb>2.0.co;2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
To understand how the molecular chaperone Hsp90 participates in conformational maturation of the estrogen receptor (ER), we analyzed the interaction of immobilized purified avian Hsp90 with mammalian cytosolic ER. Hsp90 was either immunoadsorbed to BF4 antibody-Sepharose or GST-Hsp90 fusion protein (GST.90) was adsorbed to glutathione-Sepharose. GST.90 was able to retain specifically ER, similarly to immunoadsorbed Hsp90. When cells were treated with estradiol and the hormone treatment was maintained during cell homogenization, binding, and washing steps, GST.90 still interacted efficiently with ER, suggesting that ER may form complexes with Hsp90 even after its activation by hormone and salt extraction from nuclei. The GST.90-ER interaction was consistently reduced in the presence of increasing concentrations of potassium chloride or when cytosolic ER-Hsp90 complexes were previously stabilized by molybdate, indicating that GST.90-ER complexes behave like cytosolic Hsp90-ER complexes. A purified thioredoxin-ER fusion protein was also able to form complexes with GST.90, suggesting that the presence of other chaperones is not required. ER was retained only by GST.90 deletion mutants bearing an intact Hsp90 N-terminal region (1-224), the interaction being more efficient when the charged region A was present in the mutant (1-334). The N-terminal fragment 1-334, devoid of the dimeric GST moiety, was also able to interact with ER, pointing to the monomeric N-terminal adenosine triphosphate binding region of Hsp90 (1-224) as the region necessary and sufficient for interaction. These results contribute to understand the Hsp90-dependent process responsible for conformational competence of ER.
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Affiliation(s)
- L Bouhouche-Chatelier
- Institut Cochin de Génétique Moléculaire, Centre National de la Recherche Scientifique-Unité Propre de Recherche, Department of Endocrinology, Paris, France
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Haverinen M, Passinen S, Syvälä H, Pasanen S, Manninen T, Tuohimaa P, Ylikomi T. Heat shock protein 90 and the nuclear transport of progesterone receptor. Cell Stress Chaperones 2001; 6:256-62. [PMID: 11599567 PMCID: PMC434407 DOI: 10.1379/1466-1268(2001)006<0256:hspatn>2.0.co;2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Steroid receptors exist as large oligomeric complexes in hypotonic cell extracts. In the present work, we studied the nuclear transport of the 2 major components of the oligomeric complex, the receptor itself and the heat shock protein 90 (Hsp90), by using different in vitro transport systems: digitonin permeabilized cells and purified nuclei. We demonstrate that the stabilized oligomeric complex of progesterone receptor (PR) cannot be transported into the nucleus and that unliganded PR salt dissociated from Hsp90 is transported into the nucleus. When nonstabilized PR oligomer was introduced into the nuclear transport system, the complex dissociated and the PR but not the Hsp90 was transported into the nucleus. If PR exists as an oligomeric form after synthesis, as suggested by the experiments with reticulocyte lysate, the present results suggest that the complex is short-lived and is dissociated before or during nuclear transport. Thus, the role of Hsp90 in PR action is likely to reside in the Hsp90-assisted chaperoning process of PR preceding nuclear transport of the receptor.
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Affiliation(s)
- M Haverinen
- Department of Cell Biology, Graduate School of Biosciences, University of Tampere, Finland
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Shao J, Grammatikakis N, Scroggins BT, Uma S, Huang W, Chen JJ, Hartson SD, Matts RL. Hsp90 regulates p50(cdc37) function during the biogenesis of the activeconformation of the heme-regulated eIF2 alpha kinase. J Biol Chem 2001; 276:206-14. [PMID: 11036079 DOI: 10.1074/jbc.m007583200] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Recent studies indicate that p50(cdc37) facilitates Hsp90-mediated biogenesis of certain protein kinases. In this report, we examined whether p50(cdc37) is required for the biogenesis of the heme-regulated eIF2 alpha kinase (HRI) in reticulocyte lysate. p50(cdc37) interacted with nascent HRI co-translationally and this interaction persisted during the maturation and activation of HRI. p50(cdc37) stimulated HRI's activation in response to heme deficiency, but did not activate HRI per se. p50(cdc37) function was specific to immature and inactive forms of the kinase. Analysis of mutant Cdc37 gene products indicated that the N-terminal portion of p50(cdc37) interacted with immature HRI, but not with Hsp90, while the C-terminal portion of p50(cdc37) interacted with Hsp90. The Hsp90-specific inhibitor geldanamycin disrupted the ability of both Hsp90 and p50(cdc37) to bind HRI and promote its activation, but did not disrupt the native association of p50(cdc37) with Hsp90. A C-terminal truncated mutant of p50(cdc37) inhibited HRI's activation, prevented the interaction of Hsp90 with HRI, and bound to HRI irrespective of geldanamycin treatment. Additionally, native complexes of HRI with p50(cdc37) were detected in cultured K562 erythroleukemia cells. These results suggest that p50(cdc37) provides an activity essential to HRI biogenesis via a process regulated by nucleotide-mediated conformational switching of its partner Hsp90.
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Affiliation(s)
- J Shao
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, Oklahoma 74078, USA
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Nardai G, Sass B, Eber J, Orosz G, Csermely P. Reactive cysteines of the 90-kDa heat shock protein, Hsp90. Arch Biochem Biophys 2000; 384:59-67. [PMID: 11147836 DOI: 10.1006/abbi.2000.2075] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The 90-kDa heat shock protein (Hsp90) is the most abundant molecular chaperone of the eukaryotic cytoplasm. Its cysteine groups participate in the interactions of Hsp90 with the heme-regulated eIF-2alpha kinase and molybdate, a stabilizer of Hsp90-protein complexes. In our present studies we investigated the reactivity of the sulfhydryl groups of Hsp90. Our data indicate that Hsp90 as well as two Hsp90 peptides containing Cys-521 and Cys-589/590 are able to reduce cytochrome c. The effect of Hsp90 can be blocked by sulfhydryl reagents including arsenite and cadmium, which indicates the involvement of the vicinal cysteines Cys589/590 in the reduction of cytochrome c. Hsp90 neither reduces the disulfide bonds of insulin nor possesses a NADPH:quinone oxidoreductase activity. Oxidizing conditions impair the chaperone activity of Hsp90 toward citrate synthase. The high and specific reactivity of Hsp90 cysteine groups toward cytochrome c may indicate a role of this chaperone in modulation of the redox status of the cytosol in resting and apoptotic cells.
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Affiliation(s)
- G Nardai
- Department of Medical Chemistry, Semmelweis University, Budapest, Hungary
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