1
|
Britt HM, Cragnolini T, Thalassinos K. Integration of Mass Spectrometry Data for Structural Biology. Chem Rev 2021; 122:7952-7986. [PMID: 34506113 DOI: 10.1021/acs.chemrev.1c00356] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Mass spectrometry (MS) is increasingly being used to probe the structure and dynamics of proteins and the complexes they form with other macromolecules. There are now several specialized MS methods, each with unique sample preparation, data acquisition, and data processing protocols. Collectively, these methods are referred to as structural MS and include cross-linking, hydrogen-deuterium exchange, hydroxyl radical footprinting, native, ion mobility, and top-down MS. Each of these provides a unique type of structural information, ranging from composition and stoichiometry through to residue level proximity and solvent accessibility. Structural MS has proved particularly beneficial in studying protein classes for which analysis by classic structural biology techniques proves challenging such as glycosylated or intrinsically disordered proteins. To capture the structural details for a particular system, especially larger multiprotein complexes, more than one structural MS method with other structural and biophysical techniques is often required. Key to integrating these diverse data are computational strategies and software solutions to facilitate this process. We provide a background to the structural MS methods and briefly summarize other structural methods and how these are combined with MS. We then describe current state of the art approaches for the integration of structural MS data for structural biology. We quantify how often these methods are used together and provide examples where such combinations have been fruitful. To illustrate the power of integrative approaches, we discuss progress in solving the structures of the proteasome and the nuclear pore complex. We also discuss how information from structural MS, particularly pertaining to protein dynamics, is not currently utilized in integrative workflows and how such information can provide a more accurate picture of the systems studied. We conclude by discussing new developments in the MS and computational fields that will further enable in-cell structural studies.
Collapse
Affiliation(s)
- Hannah M Britt
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London WC1E 6BT, United Kingdom
| | - Tristan Cragnolini
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London WC1E 6BT, United Kingdom.,Institute of Structural and Molecular Biology, Birkbeck College, University of London, London WC1E 7HX, United Kingdom
| | - Konstantinos Thalassinos
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London WC1E 6BT, United Kingdom.,Institute of Structural and Molecular Biology, Birkbeck College, University of London, London WC1E 7HX, United Kingdom
| |
Collapse
|
2
|
Singh A, Phogat J, Yadav A, Dabur R. The dependency of autophagy and ubiquitin proteasome system during skeletal muscle atrophy. Biophys Rev 2021; 13:203-219. [PMID: 33927785 PMCID: PMC8046863 DOI: 10.1007/s12551-021-00789-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 02/24/2021] [Indexed: 12/14/2022] Open
Abstract
Among the four proteolytic systems in the cell, autophagy and the ubiquitin-proteasome system (UPS) are the main proteolytic events that allow for the removal of cell debris and proteins to maintain cellular homeostasis. Previous studies have revealed that these systems perform their functions independently of each other. However, recent studies indicate the existence of regulatory interactions between these proteolytic systems via ubiquitinated tags and a reciprocal regulation mechanism with several crosstalk points. UPS plays an important role in the elimination of short-lived/soluble misfolded proteins, whereas autophagy eliminates defective organelles and persistent insoluble protein aggregates. Both of these systems seem to act independently; however, disruption of one pathway affects the activity of the other pathway and contributes to different pathological conditions. This review summarizes the recent findings on direct and indirect dependencies of autophagy and UPS and their execution at the molecular level along with the important drug targets in skeletal muscle atrophy.
Collapse
Affiliation(s)
- Ajay Singh
- Clinical Biochemistry Laboratory, Department of Biochemistry, Maharshi Dayanand University, Rohtak, Haryana 124001 India
| | - Jatin Phogat
- Clinical Biochemistry Laboratory, Department of Biochemistry, Maharshi Dayanand University, Rohtak, Haryana 124001 India
| | - Aarti Yadav
- Clinical Biochemistry Laboratory, Department of Biochemistry, Maharshi Dayanand University, Rohtak, Haryana 124001 India
| | - Rajesh Dabur
- Clinical Biochemistry Laboratory, Department of Biochemistry, Maharshi Dayanand University, Rohtak, Haryana 124001 India
| |
Collapse
|
3
|
Mendes ML, Dittmar G. Analysis of the Dynamic Proteasome Structure by Cross-Linking Mass Spectrometry. Biomolecules 2021; 11:biom11040505. [PMID: 33801594 PMCID: PMC8067131 DOI: 10.3390/biom11040505] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 03/19/2021] [Accepted: 03/23/2021] [Indexed: 12/12/2022] Open
Abstract
The 26S proteasome is a macromolecular complex that degrades proteins maintaining cell homeostasis; thus, determining its structure is a priority to understand its function. Although the 20S proteasome's structure has been known for some years, the highly dynamic nature of the 19S regulatory particle has presented a challenge to structural biologists. Advances in cryo-electron microscopy (cryo-EM) made it possible to determine the structure of the 19S regulatory particle and showed at least seven different conformational states of the proteasome. However, there are still many questions to be answered. Cross-linking mass spectrometry (CLMS) is now routinely used in integrative structural biology studies, and it promises to take integrative structural biology to the next level, answering some of these questions.
Collapse
|
4
|
Abstract
The 26S proteasome is the most complex ATP-dependent protease machinery, of ~2.5 MDa mass, ubiquitously found in all eukaryotes. It selectively degrades ubiquitin-conjugated proteins and plays fundamentally indispensable roles in regulating almost all major aspects of cellular activities. To serve as the sole terminal "processor" for myriad ubiquitylation pathways, the proteasome evolved exceptional adaptability in dynamically organizing a large network of proteins, including ubiquitin receptors, shuttle factors, deubiquitinases, AAA-ATPase unfoldases, and ubiquitin ligases, to enable substrate selectivity and processing efficiency and to achieve regulation precision of a vast diversity of substrates. The inner working of the 26S proteasome is among the most sophisticated, enigmatic mechanisms of enzyme machinery in eukaryotic cells. Recent breakthroughs in three-dimensional atomic-level visualization of the 26S proteasome dynamics during polyubiquitylated substrate degradation elucidated an extensively detailed picture of its functional mechanisms, owing to progressive methodological advances associated with cryogenic electron microscopy (cryo-EM). Multiple sites of ubiquitin binding in the proteasome revealed a canonical mode of ubiquitin-dependent substrate engagement. The proteasome conformation in the act of substrate deubiquitylation provided insights into how the deubiquitylating activity of RPN11 is enhanced in the holoenzyme and is coupled to substrate translocation. Intriguingly, three principal modes of coordinated ATP hydrolysis in the heterohexameric AAA-ATPase motor were discovered to regulate intermediate functional steps of the proteasome, including ubiquitin-substrate engagement, deubiquitylation, initiation of substrate translocation and processive substrate degradation. The atomic dissection of the innermost working of the 26S proteasome opens up a new era in our understanding of the ubiquitin-proteasome system and has far-reaching implications in health and disease.
Collapse
Affiliation(s)
- Youdong Mao
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, 02215, Massachusetts, USA. .,School of Physics, Center for Quantitative Biology, Peking University, Beijing, 100871, China.
| |
Collapse
|
5
|
Molecular and cellular dynamics of the 26S proteasome. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2020; 1869:140583. [PMID: 33321258 DOI: 10.1016/j.bbapap.2020.140583] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 12/07/2020] [Accepted: 12/09/2020] [Indexed: 01/16/2023]
Abstract
In eukaryotic cells, the ubiquitin-proteasome system serves to remove proteins that are either dysfunctional or no longer needed. The 26S proteasome is a 2.5 MDa multisubunit complex comprising the 20S core particle, where degradation is executed, and one or two regulatory particles which prepare substrates for degradation. Whereas the 20S core particles of several species had been studied extensively by X-ray crystallography, the 26S holocomplex structure had remained elusive for a long time. Recent advances in single-particle cryo-electron microscopy have changed the situation and provided atomic resolution models of this intriguing molecular machine and its dynamics. Besides, cryo-electron tomography enables structural studies in situ, providing molecular resolution images of macromolecules inside pristinely preserved cellular environments. This has greatly contributed to our understanding of proteasome dynamics in the context of cells.
Collapse
|
6
|
Morozov AV, Karpov VL. Proteasomes and Several Aspects of Their Heterogeneity Relevant to Cancer. Front Oncol 2019; 9:761. [PMID: 31456945 PMCID: PMC6700291 DOI: 10.3389/fonc.2019.00761] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 07/29/2019] [Indexed: 01/19/2023] Open
Abstract
The life of every organism is dependent on the fine-tuned mechanisms of protein synthesis and breakdown. The degradation of most intracellular proteins is performed by the ubiquitin proteasome system (UPS). Proteasomes are central elements of the UPS and represent large multisubunit protein complexes directly responsible for the protein degradation. Accumulating data indicate that there is an intriguing diversity of cellular proteasomes. Different proteasome forms, containing different subunits and attached regulators have been described. In addition, proteasomes specific for a particular tissue were identified. Cancer cells are highly dependent on the proper functioning of the UPS in general, and proteasomes in particular. At the same time, the information regarding the role of different proteasome forms in cancer is limited. This review describes the functional and structural heterogeneity of proteasomes, their association with cancer as well as several established and novel proteasome-directed therapeutic strategies.
Collapse
Affiliation(s)
- Alexey V Morozov
- Laboratory of Regulation of Intracellular Proteolysis, W.A. Engelhardt Institute of Molecular Biology RAS, Moscow, Russia
| | - Vadim L Karpov
- Laboratory of Regulation of Intracellular Proteolysis, W.A. Engelhardt Institute of Molecular Biology RAS, Moscow, Russia
| |
Collapse
|
7
|
Gonos ES, Kapetanou M, Sereikaite J, Bartosz G, Naparło K, Grzesik M, Sadowska-Bartosz I. Origin and pathophysiology of protein carbonylation, nitration and chlorination in age-related brain diseases and aging. Aging (Albany NY) 2019; 10:868-901. [PMID: 29779015 PMCID: PMC5990388 DOI: 10.18632/aging.101450] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 05/08/2018] [Indexed: 12/11/2022]
Abstract
Non-enzymatic protein modifications occur inevitably in all living systems. Products of such modifications accumulate during aging of cells and organisms and may contribute to their age-related functional deterioration. This review presents the formation of irreversible protein modifications such as carbonylation, nitration and chlorination, modifications by 4-hydroxynonenal, removal of modified proteins and accumulation of these protein modifications during aging of humans and model organisms, and their enhanced accumulation in age-related brain diseases.
Collapse
Affiliation(s)
- Efstathios S Gonos
- National Hellenic Research Foundation, Institute of Biology, Medicinal Chemistry and Biotechnology, Athens 11635, Greece
| | - Marianna Kapetanou
- National Hellenic Research Foundation, Institute of Biology, Medicinal Chemistry and Biotechnology, Athens 11635, Greece.,Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Athens, Athens 15701, Greece
| | - Jolanta Sereikaite
- Department of Chemistry and Bioengineering, Faculty of Fundamental Sciences, Vilnius Gediminas Technical University, Vilnius 2040, Lithuania
| | - Grzegorz Bartosz
- Department of Molecular Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz 90-236, Poland
| | - Katarzyna Naparło
- Department of Analytical Biochemistry, Faculty of Biology and Agriculture, University of Rzeszow, Rzeszow 35-601, Poland
| | - Michalina Grzesik
- Department of Analytical Biochemistry, Faculty of Biology and Agriculture, University of Rzeszow, Rzeszow 35-601, Poland
| | - Izabela Sadowska-Bartosz
- Department of Analytical Biochemistry, Faculty of Biology and Agriculture, University of Rzeszow, Rzeszow 35-601, Poland
| |
Collapse
|
8
|
Chaves CF, Mazzotti DR, Cendoroglo MS, Ramos LR, Tufik S, Silva VCD, D'Almeida V. Genes related to maintenance of autophagy and successful aging. ARQUIVOS DE NEURO-PSIQUIATRIA 2019; 76:831-839. [PMID: 30698207 DOI: 10.1590/0004-282x20180142] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 09/25/2018] [Indexed: 01/11/2023]
Abstract
Considering aging as a phenomenon in which there is a decline in essential processes for cell survival, we investigated the autophagic and proteasome pathways in three different groups: young, older and oldest old male adults. The expression profile of autophagic pathway-related genes was carried out in peripheral blood, and the proteasome quantification was performed in plasma. No significant changes were found in plasma proteasome concentrations or in correlations between proteasome concentrations and ages. However, some autophagy- and/or apoptosis-related genes were differentially expressed. In addition, the network and enrichment analysis showed an interaction between four of the five differentially expressed genes and an association of these genes with the transcriptional process. Considering that the oldest old individuals maintained both the expression of genes linked to the autophagic machinery, and the proteasome levels, when compared with the older group, we concluded that these factors could be considered crucial for successful aging.
Collapse
Affiliation(s)
| | - Diego Robles Mazzotti
- Universidade Federal de São Paulo, Departamento de Psicobiologia, São Paulo SP, Brasil
| | | | - Luiz Roberto Ramos
- Universidade Federal de São Paulo, Departamento de Medicina Preventiva, São Paulo SP, Brasil
| | - Sergio Tufik
- Universidade Federal de São Paulo, Departamento de Psicobiologia, São Paulo SP, Brasil
| | | | - Vânia D'Almeida
- Universidade Federal de São Paulo, Departamento de Psicobiologia, São Paulo SP, Brasil
| |
Collapse
|
9
|
Kravchuk OI, Lyupina YV, Erokhov PA, Finoshin AD, Adameyko KI, Mishyna MY, Moiseenko AV, Sokolova OS, Orlova OV, Beljelarskaya SN, Serebryakova MV, Indeykina MI, Bugrova AE, Kononikhin AS, Mikhailov VS. Characterization of the 20S proteasome of the lepidopteran, Spodoptera frugiperda. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2019; 1867:840-853. [PMID: 31228587 DOI: 10.1016/j.bbapap.2019.06.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 06/05/2019] [Accepted: 06/17/2019] [Indexed: 02/08/2023]
Abstract
Multiple complexes of 20S proteasomes with accessory factors play an essential role in proteolysis in eukaryotic cells. In this report, several forms of 20S proteasomes from extracts of Spodoptera frugiperda (Sf9) cells were separated using electrophoresis in a native polyacrylamide gel and examined for proteolytic activity in the gel and by Western blotting. Distinct proteasome bands isolated from the gel were subjected to liquid chromatography-tandem mass spectrometry and identified as free core particles (CP) and complexes of CP with one or two dimers of assembly chaperones PAC1-PAC2 and activators PA28γ or PA200. In contrast to the activators PA28γ and PA200 that regulate the access of protein substrates to the internal proteolytic chamber of CP in an ATP-independent manner, the 19S regulatory particle (RP) in 26S proteasomes performs stepwise substrate unfolding and opens the chamber gate in an ATP-dependent manner. Electron microscopic analysis suggested that spontaneous dissociation of RP in isolated 26S proteasomes leaves CPs with different gate sizes related presumably to different stages in the gate opening. The primary structure of 20S proteasome subunits in Sf9 cells was determined by a search of databases and by sequencing. The protein sequences were confirmed by mass spectrometry and verified by 2D gel electrophoresis. The relative rates of sequence divergence in the evolution of 20S proteasome subunits, the assembly chaperones and activators were determined by using bioinformatics. The data confirmed the conservation of regular CP subunits and PA28γ, a more accelerated evolution of PAC2 and PA200, and especially high divergence rates of PAC1.
Collapse
Affiliation(s)
- Oksana I Kravchuk
- N.K. Koltzov Institute of Developmental Biology, Russian Academy of Sciences, 26 Vavilova str., Moscow 119334, Russia
| | - Yulia V Lyupina
- N.K. Koltzov Institute of Developmental Biology, Russian Academy of Sciences, 26 Vavilova str., Moscow 119334, Russia
| | - Pavel A Erokhov
- N.K. Koltzov Institute of Developmental Biology, Russian Academy of Sciences, 26 Vavilova str., Moscow 119334, Russia
| | - Alexander D Finoshin
- N.K. Koltzov Institute of Developmental Biology, Russian Academy of Sciences, 26 Vavilova str., Moscow 119334, Russia
| | - Kim I Adameyko
- N.K. Koltzov Institute of Developmental Biology, Russian Academy of Sciences, 26 Vavilova str., Moscow 119334, Russia
| | - Maryia Yu Mishyna
- M.V. Lomonosov Moscow State University, Faculty of Biology, 1-12 Leninskie Gory, Moscow 119991, Russia
| | - Andrey V Moiseenko
- M.V. Lomonosov Moscow State University, Faculty of Biology, 1-12 Leninskie Gory, Moscow 119991, Russia
| | - Olga S Sokolova
- M.V. Lomonosov Moscow State University, Faculty of Biology, 1-12 Leninskie Gory, Moscow 119991, Russia
| | - Olga V Orlova
- V.A. Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 32 Vavilova str., Moscow 119334, Russia
| | - Svetlana N Beljelarskaya
- V.A. Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 32 Vavilova str., Moscow 119334, Russia
| | - Marina V Serebryakova
- A.N. Belozersky Institute of Physico-Chemical Biology MSU, 1c40 Leniniskie Gory, Moscow 119234, Russia
| | - Maria I Indeykina
- N.M. Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, 4 Kosygina str., Moscow 119334, Russia
| | - Anna E Bugrova
- N.M. Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, 4 Kosygina str., Moscow 119334, Russia
| | - Alexey S Kononikhin
- N.M. Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, 4 Kosygina str., Moscow 119334, Russia; Skolkovo Institute of Science and Technology, 3 Ulitsa Nobelya, Moscow region, Skolkovo 121205, Russia
| | - Victor S Mikhailov
- N.K. Koltzov Institute of Developmental Biology, Russian Academy of Sciences, 26 Vavilova str., Moscow 119334, Russia.
| |
Collapse
|
10
|
Marshall RS, Vierstra RD. Dynamic Regulation of the 26S Proteasome: From Synthesis to Degradation. Front Mol Biosci 2019; 6:40. [PMID: 31231659 PMCID: PMC6568242 DOI: 10.3389/fmolb.2019.00040] [Citation(s) in RCA: 138] [Impact Index Per Article: 27.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 05/09/2019] [Indexed: 01/12/2023] Open
Abstract
All eukaryotes rely on selective proteolysis to control the abundance of key regulatory proteins and maintain a healthy and properly functioning proteome. Most of this turnover is catalyzed by the 26S proteasome, an intricate, multi-subunit proteolytic machine. Proteasomes recognize and degrade proteins first marked with one or more chains of poly-ubiquitin, the addition of which is actuated by hundreds of ligases that individually identify appropriate substrates for ubiquitylation. Subsequent proteasomal digestion is essential and influences a myriad of cellular processes in species as diverse as plants, fungi and humans. Importantly, dysfunction of 26S proteasomes is associated with numerous human pathologies and profoundly impacts crop performance, thus making an understanding of proteasome dynamics critically relevant to almost all facets of human health and nutrition. Given this widespread significance, it is not surprising that sophisticated mechanisms have evolved to tightly regulate 26S proteasome assembly, abundance and activity in response to demand, organismal development and stress. These include controls on transcription and chaperone-mediated assembly, influences on proteasome localization and activity by an assortment of binding proteins and post-translational modifications, and ultimately the removal of excess or damaged particles via autophagy. Intriguingly, the autophagic clearance of damaged 26S proteasomes first involves their modification with ubiquitin, thus connecting ubiquitylation and autophagy as key regulatory events in proteasome quality control. This turnover is also influenced by two distinct biomolecular condensates that coalesce in the cytoplasm, one attracting damaged proteasomes for autophagy, and the other reversibly storing proteasomes during carbon starvation to protect them from autophagic clearance. In this review, we describe the current state of knowledge regarding the dynamic regulation of 26S proteasomes at all stages of their life cycle, illustrating how protein degradation through this proteolytic machine is tightly controlled to ensure optimal growth, development and longevity.
Collapse
Affiliation(s)
- Richard S Marshall
- Department of Biology, Washington University in St. Louis, St. Louis, MO, United States
| | - Richard D Vierstra
- Department of Biology, Washington University in St. Louis, St. Louis, MO, United States
| |
Collapse
|
11
|
Cryo-EM structures of the archaeal PAN-proteasome reveal an around-the-ring ATPase cycle. Proc Natl Acad Sci U S A 2018; 116:534-539. [PMID: 30559193 PMCID: PMC6329974 DOI: 10.1073/pnas.1817752116] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Proteasomes are ATP-dependent proteases that occur in all three domains of life, and are the principal molecular machines for the regulated degradation of intracellular proteins. The eukaryotic 26S proteasome has been extensively characterized. However, its evolutionary precursor, the archaeal proteasome–ATPase complex, remains poorly understood. The inherent instability of these primordial protein complexes has so far hindered attempts for detailed structure determination. Using cryo-EM single-particle analysis, we were able to determine the structure of an archaeal PAN-proteasome, which is a complex of the proteolytic core and the ATPase PAN (proteasome-activating nucleotidase). The structures reported here not only provide insights into the functional cycle of PAN-proteasomes, they reveal a fundamental mechanism of ATPase operation. Proteasomes occur in all three domains of life, and are the principal molecular machines for the regulated degradation of intracellular proteins. They play key roles in the maintenance of protein homeostasis, and control vital cellular processes. While the eukaryotic 26S proteasome is extensively characterized, its putative evolutionary precursor, the archaeal proteasome, remains poorly understood. The primordial archaeal proteasome consists of a 20S proteolytic core particle (CP), and an AAA-ATPase module. This minimal complex degrades protein unassisted by non-ATPase subunits that are present in a 26S proteasome regulatory particle (RP). Using cryo-EM single-particle analysis, we determined structures of the archaeal CP in complex with the AAA-ATPase PAN (proteasome-activating nucleotidase). Five conformational states were identified, elucidating the functional cycle of PAN, and its interaction with the CP. Coexisting nucleotide states, and correlated intersubunit signaling features, coordinate rotation of the PAN-ATPase staircase, and allosterically regulate N-domain motions and CP gate opening. These findings reveal the structural basis for a sequential around-the-ring ATPase cycle, which is likely conserved in AAA-ATPases.
Collapse
|
12
|
Cotranslocational processing of the protein substrate calmodulin by an AAA+ unfoldase occurs via unfolding and refolding intermediates. Proc Natl Acad Sci U S A 2018; 115:E4786-E4795. [PMID: 29735657 DOI: 10.1073/pnas.1721811115] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Protein remodeling by AAA+ enzymes is central for maintaining proteostasis in a living cell. However, a detailed structural description of how this is accomplished at the level of the substrate molecules that are acted upon is lacking. Here, we combine chemical cross-linking and methyl transverse relaxation-optimized NMR spectroscopy to study, at atomic resolution, the stepwise unfolding and subsequent refolding of the two-domain substrate calmodulin by the VAT AAA+ unfoldase from Thermoplasma acidophilum By engineering intermolecular disulphide bridges between the substrate and VAT we trap the substrate at different stages of translocation, allowing structural studies throughout the translocation process. Our results show that VAT initiates substrate translocation by pulling on intrinsically unstructured N or C termini of substrate molecules without showing specificity for a particular amino acid sequence. Although the B1 domain of protein G is shown to unfold cooperatively, translocation of calmodulin leads to the formation of intermediates, and these differ on an individual domain level in a manner that depends on whether pulling is from the N or C terminus. The approach presented generates an atomic resolution picture of substrate unfolding and subsequent refolding by unfoldases that can be quite different from results obtained via in vitro denaturation experiments.
Collapse
|
13
|
Milder degenerative effects of Carfilzomib vs. Bortezomib in the Drosophila model: a link to clinical adverse events. Sci Rep 2017; 7:17802. [PMID: 29259189 PMCID: PMC5736585 DOI: 10.1038/s41598-017-17596-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 11/27/2017] [Indexed: 12/15/2022] Open
Abstract
Proteasome inhibitors, e.g. Bortezomib (BTZ) and Carfilzomib (CFZ), have demonstrated clinical efficacy against haematological cancers. Interestingly, several adverse effects are less common, compared to BTZ, in patients treated with CFZ. As the molecular details of these observations remain not well understood we assayed the pathophysiological effects of CFZ vs. BTZ in the Drosophila experimental model. Mass Spectrometry analyses showed that neither CFZ nor BTZ are hydrolysed in flies’ tissues, while at doses inducing similar inhibition of the rate limiting for protein breakdown chymotrypsin-like (CT-L) proteasomal activity, CFZ treatment resulted in less intense increase of oxidative stress or activation of antioxidant and proteostatic modules. Also, despite comparable cardiotoxicity likely due to disrupted mitochondrial function, CFZ did not affect developmental processes, showed minimal neuromuscular defects and reduced to a lesser extent flies’ healthspan. Studies in flies, human cancer cell lines and blood cells isolated from Multiple Myeloma patients treated with CFZ or BTZ revealed, that the increased BTZ toxicity likely relates to partial co-inhibition of the caspase-like (C-L) proteasomal activity Supportively, co-treating flies with CFZ and a C-L selective proteasome inhibitor exacerbated CFZ-mediated toxicity. Our findings provide a reasonable explanation for the differential adverse effects of CFZ and BTZ in the clinic.
Collapse
|
14
|
Ishii K, Zhou M, Uchiyama S. Native mass spectrometry for understanding dynamic protein complex. Biochim Biophys Acta Gen Subj 2017; 1862:275-286. [PMID: 28965879 DOI: 10.1016/j.bbagen.2017.09.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 09/17/2017] [Accepted: 09/19/2017] [Indexed: 12/13/2022]
Abstract
Biomolecules have evolved to perform specific and sophisticated activities in a highly coordinated manner organizing into multi-component complexes consisting of proteins, nucleic acids, cofactors or ligands. Understanding such complexes represents a task in earnest for modern bioscience. Traditional structural techniques when extrapolating to macromolecules of ever increasing sizes are confronted with limitations posed by the difficulty in enrichment, solubility, stability as well as lack of homogeneity of these complexes. Alternative approaches are therefore prompted to bridge the gap, one of which is native mass spectrometry. Here we demonstrate the strength of native mass spectrometry, used alone or in combination with other biophysical methods such as analytical ultracentrifugation, small-angle neutron scattering, and small-angle X-ray scattering etc., in addressing dynamic aspects of protein complexes including structural reorganization, subunit exchange, as well as the assembly/disassembly processes in solution that are dictated by transient non-covalent interactions. We review recent studies from our laboratories and others applying native mass spectrometry to both soluble and membrane-embedded assemblies. This article is part of a Special Issue entitled "Biophysical Exploration of Dynamical Ordering of Biomolecular Systems" edited by Dr. Koichi Kato.
Collapse
Affiliation(s)
- Kentaro Ishii
- Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan
| | - Min Zhou
- Institute of Bio-analytical Chemistry, School of Chemical Engineering, Nanjing University of Science and Technology, No. 200 Xiaolingwei Street, Nanjing 210094, China.
| | - Susumu Uchiyama
- Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan; Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
| |
Collapse
|
15
|
Wagner J, Schaffer M, Fernández-Busnadiego R. Cryo-electron tomography-the cell biology that came in from the cold. FEBS Lett 2017; 591:2520-2533. [PMID: 28726246 DOI: 10.1002/1873-3468.12757] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 06/26/2017] [Accepted: 07/14/2017] [Indexed: 12/27/2022]
Abstract
Cryo-electron tomography (cryo-ET) provides high-resolution 3D views into cells pristinely preserved by vitrification. Recent technical advances such as direct electron detectors, the Volta phase plate and cryo-focused ion beam milling have dramatically pushed image quality and expanded the range of cryo-ET applications. Cryo-ET not only allows mapping the positions and interactions of macromolecules within their intact cellular context, but can also reveal their in situ structure at increasing resolution. Here, we review how recent work using cutting-edge cryo-ET technologies is starting to provide fresh views into different aspects of cellular biology at an unprecedented level of detail. We anticipate that these developments will soon make cryo-ET a fundamental technique in cell biology.
Collapse
|
16
|
Natisvili T, Yandim C, Silva R, Emanuelli G, Krueger F, Nageshwaran S, Festenstein R. Transcriptional Activation of Pericentromeric Satellite Repeats and Disruption of Centromeric Clustering upon Proteasome Inhibition. PLoS One 2016; 11:e0165873. [PMID: 27806100 PMCID: PMC5091837 DOI: 10.1371/journal.pone.0165873] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 10/19/2016] [Indexed: 12/27/2022] Open
Abstract
Heterochromatinisation of pericentromeres, which in mice consist of arrays of major satellite repeats, are important for centromere formation and maintenance of genome stability. The dysregulation of this process has been linked to genomic stress and various cancers. Here we show in mice that the proteasome binds to major satellite repeats and proteasome inhibition by MG132 results in their transcriptional de-repression; this de-repression is independent of cell-cycle perturbation. The transcriptional activation of major satellite repeats upon proteasome inhibition is accompanied by delocalisation of heterochromatin protein 1 alpha (HP1α) from chromocentres, without detectable change in the levels of histone H3K9me3, H3K4me3, H3K36me3 and H3 acetylation on the major satellite repeats. Moreover, inhibition of the proteasome was found to increase the number of chromocentres per cell, reflecting destabilisation of the chromocentre structures. Our findings suggest that the proteasome plays a role in maintaining heterochromatin integrity of pericentromeres.
Collapse
Affiliation(s)
- Theona Natisvili
- Gene Control Mechanisms and Disease Group, Department of Medicine, Division of Brain Sciences and MRC Clinical Sciences Centre, Imperial College London, Hammersmith Hospital, London, United Kingdom
| | - Cihangir Yandim
- Gene Control Mechanisms and Disease Group, Department of Medicine, Division of Brain Sciences and MRC Clinical Sciences Centre, Imperial College London, Hammersmith Hospital, London, United Kingdom
| | - Raquel Silva
- Gene Control Mechanisms and Disease Group, Department of Medicine, Division of Brain Sciences and MRC Clinical Sciences Centre, Imperial College London, Hammersmith Hospital, London, United Kingdom
| | - Giulia Emanuelli
- Gene Control Mechanisms and Disease Group, Department of Medicine, Division of Brain Sciences and MRC Clinical Sciences Centre, Imperial College London, Hammersmith Hospital, London, United Kingdom
| | - Felix Krueger
- Bioinformatics Group, Babraham Institute, Cambridge, United Kingdom
| | - Sathiji Nageshwaran
- Gene Control Mechanisms and Disease Group, Department of Medicine, Division of Brain Sciences and MRC Clinical Sciences Centre, Imperial College London, Hammersmith Hospital, London, United Kingdom
| | - Richard Festenstein
- Gene Control Mechanisms and Disease Group, Department of Medicine, Division of Brain Sciences and MRC Clinical Sciences Centre, Imperial College London, Hammersmith Hospital, London, United Kingdom
- * E-mail:
| |
Collapse
|
17
|
Bonomi M, Camilloni C, Vendruscolo M. Metadynamic metainference: Enhanced sampling of the metainference ensemble using metadynamics. Sci Rep 2016; 6:31232. [PMID: 27561930 PMCID: PMC4999896 DOI: 10.1038/srep31232] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 07/11/2016] [Indexed: 01/23/2023] Open
Abstract
Accurate and precise structural ensembles of proteins and macromolecular complexes can be obtained with metainference, a recently proposed Bayesian inference method that integrates experimental information with prior knowledge and deals with all sources of errors in the data as well as with sample heterogeneity. The study of complex macromolecular systems, however, requires an extensive conformational sampling, which represents a separate challenge. To address such challenge and to exhaustively and efficiently generate structural ensembles we combine metainference with metadynamics and illustrate its application to the calculation of the free energy landscape of the alanine dipeptide.
Collapse
Affiliation(s)
- Massimiliano Bonomi
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | - Carlo Camilloni
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
- Department of Chemistry and Institute for Advanced Study, Technische Universität München, Lichtenbergstrasse 4, D-85747 Garching, Germany
| | - Michele Vendruscolo
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| |
Collapse
|
18
|
Wehmer M, Sakata E. Recent advances in the structural biology of the 26S proteasome. Int J Biochem Cell Biol 2016; 79:437-442. [PMID: 27498189 DOI: 10.1016/j.biocel.2016.08.008] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 08/02/2016] [Accepted: 08/03/2016] [Indexed: 11/29/2022]
Abstract
There is growing appreciation for the fundamental role of structural dynamics in the function of macromolecules. In particular, the 26S proteasome, responsible for selective protein degradation in an ATP dependent manner, exhibits dynamic conformational changes that enable substrate processing. Recent cryo-electron microscopy (cryo-EM) work has revealed the conformational dynamics of the 26S proteasome and established the function of the different conformational states. Technological advances such as direct electron detectors and image processing algorithms allowed resolving the structure of the proteasome at atomic resolution. Here we will review those studies and discuss their contribution to our understanding of proteasome function.
Collapse
Affiliation(s)
- Marc Wehmer
- Department of Molecular Structural Biology, Max Planck institute of Biochemistry, 82152, Martinsried, Germany
| | - Eri Sakata
- Department of Molecular Structural Biology, Max Planck institute of Biochemistry, 82152, Martinsried, Germany.
| |
Collapse
|
19
|
Guharoy M, Bhowmick P, Sallam M, Tompa P. Tripartite degrons confer diversity and specificity on regulated protein degradation in the ubiquitin-proteasome system. Nat Commun 2016; 7:10239. [PMID: 26732515 PMCID: PMC4729826 DOI: 10.1038/ncomms10239] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Accepted: 11/17/2015] [Indexed: 12/26/2022] Open
Abstract
Specific signals (degrons) regulate protein turnover mediated by the ubiquitin-proteasome system. Here we systematically analyse known degrons and propose a tripartite model comprising the following: (1) a primary degron (peptide motif) that specifies substrate recognition by cognate E3 ubiquitin ligases, (2) secondary site(s) comprising a single or multiple neighbouring ubiquitinated lysine(s) and (3) a structurally disordered segment that initiates substrate unfolding at the 26S proteasome. Primary degron sequences are conserved among orthologues and occur in structurally disordered regions that undergo E3-induced folding-on-binding. Posttranslational modifications can switch primary degrons into E3-binding-competent states, thereby integrating degradation with signalling pathways. Degradation-linked lysines tend to be located within disordered segments that also initiate substrate degradation by effective proteasomal engagement. Many characterized mutations and alternative isoforms with abrogated degron components are implicated in disease. These effects result from increased protein stability and interactome rewiring. The distributed nature of degrons ensures regulation, specificity and combinatorial control of degradation.
Collapse
Affiliation(s)
- Mainak Guharoy
- VIB Structural Biology Research Center (SBRC), Vrije Universiteit Brussel (VUB), Building E, Pleinlaan 2, 1050 Brussels, Belgium
| | - Pallab Bhowmick
- VIB Structural Biology Research Center (SBRC), Vrije Universiteit Brussel (VUB), Building E, Pleinlaan 2, 1050 Brussels, Belgium
| | - Mohamed Sallam
- VIB Structural Biology Research Center (SBRC), Vrije Universiteit Brussel (VUB), Building E, Pleinlaan 2, 1050 Brussels, Belgium
| | - Peter Tompa
- VIB Structural Biology Research Center (SBRC), Vrije Universiteit Brussel (VUB), Building E, Pleinlaan 2, 1050 Brussels, Belgium
- Institute of Enzymology, Research Center for Natural Sciences, Hungarian Academy of Sciences, 1117 Budapest, Hungary
| |
Collapse
|
20
|
Papaevgeniou N, Chondrogianni N. UPS Activation in the Battle Against Aging and Aggregation-Related Diseases: An Extended Review. Methods Mol Biol 2016; 1449:1-70. [PMID: 27613027 DOI: 10.1007/978-1-4939-3756-1_1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Aging is a biological process accompanied by gradual increase of damage in all cellular macromolecules, i.e., nucleic acids, lipids, and proteins. When the proteostasis network (chaperones and proteolytic systems) cannot reverse the damage load due to its excess as compared to cellular repair/regeneration capacity, failure of homeostasis is established. This failure is a major hallmark of aging and/or aggregation-related diseases. Dysfunction of the major cellular proteolytic machineries, namely the proteasome and the lysosome, has been reported during the progression of aging and aggregation-prone diseases. Therefore, activation of these pathways is considered as a possible preventive or therapeutic approach against the progression of these processes. This chapter focuses on UPS activation studies in cellular and organismal models and the effects of such activation on aging, longevity and disease prevention or reversal.
Collapse
Affiliation(s)
- Nikoletta Papaevgeniou
- Institute of Biology, Medicinal Chemistry and Biotechnology, National Hellenic Research Foundation, 48 Vassileos Constantinou Ave., Athens, 11635, Greece
| | - Niki Chondrogianni
- Institute of Biology, Medicinal Chemistry and Biotechnology, National Hellenic Research Foundation, 48 Vassileos Constantinou Ave., Athens, 11635, Greece.
| |
Collapse
|
21
|
Protonotarios ED, Baum B, Johnston A, Hunter GL, Griffin LD. An absolute interval scale of order for point patterns. J R Soc Interface 2015; 11:rsif.2014.0342. [PMID: 25079866 DOI: 10.1098/rsif.2014.0342] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Human observers readily make judgements about the degree of order in planar arrangements of points (point patterns). Here, based on pairwise ranking of 20 point patterns by degree of order, we have been able to show that judgements of order are highly consistent across individuals and the dimension of order has an interval scale structure spanning roughly 10 just-notable-differences (jnd) between disorder and order. We describe a geometric algorithm that estimates order to an accuracy of half a jnd by quantifying the variability of the size and shape of spaces between points. The algorithm is 70% more accurate than the best available measures. By anchoring the output of the algorithm so that Poisson point processes score on average 0, perfect lattices score 10 and unit steps correspond closely to jnds, we construct an absolute interval scale of order. We demonstrate its utility in biology by using this scale to quantify order during the development of the pattern of bristles on the dorsal thorax of the fruit fly.
Collapse
Affiliation(s)
- Emmanouil D Protonotarios
- CoMPLEX, University College London, London, UK Department of Computer Science, University College London, London, UK
| | - Buzz Baum
- Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Alan Johnston
- CoMPLEX, University College London, London, UK Experimental Psychology, Psychology and Language Sciences, University College London, London, UK
| | - Ginger L Hunter
- Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Lewis D Griffin
- CoMPLEX, University College London, London, UK Department of Computer Science, University College London, London, UK
| |
Collapse
|
22
|
Proteasome Activation is Mediated via a Functional Switch of the Rpt6 C-terminal Tail Following Chaperone-dependent Assembly. Sci Rep 2015; 5:14909. [PMID: 26449534 PMCID: PMC4598862 DOI: 10.1038/srep14909] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 09/11/2015] [Indexed: 11/18/2022] Open
Abstract
In the proteasome, the proteolytic 20S core particle (CP) associates with the 19S regulatory particle (RP) to degrade polyubiquitinated proteins. Six ATPases (Rpt1-Rpt6) of the RP form a hexameric Rpt ring and interact with the heptameric α ring (α1–α7) of the CP via the Rpt C-terminal tails individually binding to the α subunits. Importantly, the Rpt6 tail has been suggested to be crucial for RP assembly. Here, we show that the interaction of the CP and Rpt6 tail promotes a CP-Rpt3 tail interaction, and that they jointly mediate proteasome activation via opening the CP gate for substrate entry. The Rpt6 tail forms a novel relationship with the Nas6 chaperone, which binds to Rpt3 and regulates the CP-Rpt3 tail interaction, critically influencing cell growth and turnover of polyubiquitinated proteins. CP-Rpt6 tail binding promotes the release of Nas6 from the proteasome. Based on disulfide crosslinking that detects cognate α3-Rpt6 tail and α2-Rpt3 tail interactions in the proteasome, decreased α3-Rpt6 tail interaction facilitates robust α2-Rpt3 tail interaction that is also strongly ATP-dependent. Together, our data support the reported role of Rpt6 during proteasome assembly, and suggest that its function switches from anchoring for RP assembly into promoting Rpt3-dependent activation of the mature proteasome.
Collapse
|
23
|
Rpn10 monoubiquitination orchestrates the association of the ubiquilin-type DSK2 receptor with the proteasome. Biochem J 2015; 472:353-65. [PMID: 26450923 DOI: 10.1042/bj20150609] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 10/07/2015] [Indexed: 11/17/2022]
Abstract
Despite the progress made in understanding the roles of proteasome polyubiquitin receptors, such as the subunits Rpn10 (regulatory particle non-ATPase 10) and Rpn13, and the transient interactors Rad23 (radiation sensitivity abnormal 23) and Dsk2 (dual-specificity protein kinase 2), the mechanisms involved in their regulation are virtually unknown. Rpn10, which is found in the cell in proteasome-bound and -unbound pools, interacts with Dsk2, and this interaction has been proposed to regulate the amount of Dsk2 that gains access to the proteasome. Rpn10 monoubiquitination has emerged as a conserved mechanism with a strong effect on Rpn10 function. In the present study, we show that functional yeast proteasomes have the capacity to associate and dissociate with Rpn10 and that Rpn10 monoubiquitination decreases the Rpn10-proteasome and Rpn10-Dsk2 associations. Remarkably, this process facilitates the formation of Dsk2-proteasomes in vivo. Therefore, Rpn10 monoubiquitination acts as mechanism that serves to switch the proteasome from an 'Rpn10 high/Dsk2 low' state to an 'Rpn10 low/Dsk2 high' state. Interestingly, Rpn10-ubiquitin, with an inactivated ubiquitin-interacting motif (UIM), and Dsk2(I45S), with an inactive ubiquitin-like domain (UBL), show temperature-dependent phenotypes with multiple functional interactions.
Collapse
|
24
|
Chondrogianni N, Voutetakis K, Kapetanou M, Delitsikou V, Papaevgeniou N, Sakellari M, Lefaki M, Filippopoulou K, Gonos ES. Proteasome activation: An innovative promising approach for delaying aging and retarding age-related diseases. Ageing Res Rev 2015; 23:37-55. [PMID: 25540941 DOI: 10.1016/j.arr.2014.12.003] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 12/09/2014] [Accepted: 12/15/2014] [Indexed: 11/16/2022]
Abstract
Aging is a natural process accompanied by a progressive accumulation of damage in all constituent macromolecules (nucleic acids, lipids and proteins). Accumulation of damage in proteins leads to failure of proteostasis (or vice versa) due to increased levels of unfolded, misfolded or aggregated proteins and, in turn, to aging and/or age-related diseases. The major cellular proteolytic machineries, namely the proteasome and the lysosome, have been shown to dysfunction during aging and age-related diseases. Regarding the proteasome, it is well established that it can be activated either through genetic manipulation or through treatment with natural or chemical compounds that eventually result to extension of lifespan or deceleration of the progression of age-related diseases. This review article focuses on proteasome activation studies in several species and cellular models and their effects on aging and longevity. Moreover, it summarizes findings regarding proteasome activation in the major age-related diseases as well as in progeroid syndromes.
Collapse
Affiliation(s)
- Niki Chondrogianni
- National Hellenic Research Foundation, Institute of Biology, Medicinal Chemistry and Biotechnology, 48 Vas. Constantinou Ave., 116 35 Athens, Greece.
| | - Konstantinos Voutetakis
- National Hellenic Research Foundation, Institute of Biology, Medicinal Chemistry and Biotechnology, 48 Vas. Constantinou Ave., 116 35 Athens, Greece
| | - Marianna Kapetanou
- National Hellenic Research Foundation, Institute of Biology, Medicinal Chemistry and Biotechnology, 48 Vas. Constantinou Ave., 116 35 Athens, Greece
| | - Vasiliki Delitsikou
- National Hellenic Research Foundation, Institute of Biology, Medicinal Chemistry and Biotechnology, 48 Vas. Constantinou Ave., 116 35 Athens, Greece
| | - Nikoletta Papaevgeniou
- National Hellenic Research Foundation, Institute of Biology, Medicinal Chemistry and Biotechnology, 48 Vas. Constantinou Ave., 116 35 Athens, Greece
| | - Marianthi Sakellari
- National Hellenic Research Foundation, Institute of Biology, Medicinal Chemistry and Biotechnology, 48 Vas. Constantinou Ave., 116 35 Athens, Greece; Örebro University, Medical School, Örebro, Sweden
| | - Maria Lefaki
- National Hellenic Research Foundation, Institute of Biology, Medicinal Chemistry and Biotechnology, 48 Vas. Constantinou Ave., 116 35 Athens, Greece
| | - Konstantina Filippopoulou
- National Hellenic Research Foundation, Institute of Biology, Medicinal Chemistry and Biotechnology, 48 Vas. Constantinou Ave., 116 35 Athens, Greece
| | - Efstathios S Gonos
- National Hellenic Research Foundation, Institute of Biology, Medicinal Chemistry and Biotechnology, 48 Vas. Constantinou Ave., 116 35 Athens, Greece; Örebro University, Medical School, Örebro, Sweden.
| |
Collapse
|
25
|
Do M, Isaacson SA, McDermott G, Le Gros MA, Larabell CA. Imaging and characterizing cells using tomography. Arch Biochem Biophys 2015; 581:111-21. [PMID: 25602704 PMCID: PMC4506273 DOI: 10.1016/j.abb.2015.01.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2014] [Revised: 12/29/2014] [Accepted: 01/11/2015] [Indexed: 12/11/2022]
Abstract
We can learn much about cell function by imaging and quantifying sub-cellular structures, especially if this is done non-destructively without altering said structures. Soft X-ray tomography (SXT) is a high-resolution imaging technique for visualizing cells and their interior structure in 3D. A tomogram of the cell, reconstructed from a series of 2D projection images, can be easily segmented and analyzed. SXT has a very high specimen throughput compared to other high-resolution structure imaging modalities; for example, tomographic data for reconstructing an entire eukaryotic cell is acquired in a matter of minutes. SXT visualizes cells without the need for chemical fixation, dehydration, or staining of the specimen. As a result, the SXT reconstructions are close representations of cells in their native state. SXT is applicable to most cell types. The deep penetration of soft X-rays allows cells, even mammalian cells, to be imaged without being sectioned. Image contrast in SXT is generated by the differential attenuation soft X-ray illumination as it passes through the specimen. Accordingly, each voxel in the tomographic reconstruction has a measured linear absorption coefficient (LAC) value. LAC values are quantitative and give rise to each sub-cellular component having a characteristic LAC profile, allowing organelles to be identified and segmented from the milieu of other cell contents. In this chapter, we describe the fundamentals of SXT imaging and how this technique can answer real world questions in the study of the nucleus. We also describe the development of correlative methods for the localization of specific molecules in a SXT reconstruction. The combination of fluorescence and SXT data acquired from the same specimen produces composite 3D images, rich with detailed information on the inner workings of cells.
Collapse
Affiliation(s)
- Myan Do
- Department of Anatomy, University of California San Francisco, San Francisco, CA 94143, United States; National Center for X-ray Tomography, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States; Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States
| | - Samuel A Isaacson
- Department of Mathematics and Statistics, Boston University, Boston, MA 02215, United States
| | - Gerry McDermott
- Department of Anatomy, University of California San Francisco, San Francisco, CA 94143, United States; National Center for X-ray Tomography, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States; Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States
| | - Mark A Le Gros
- Department of Anatomy, University of California San Francisco, San Francisco, CA 94143, United States; National Center for X-ray Tomography, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States; Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States
| | - Carolyn A Larabell
- Department of Anatomy, University of California San Francisco, San Francisco, CA 94143, United States; National Center for X-ray Tomography, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States; Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States.
| |
Collapse
|
26
|
Aufderheide A, Unverdorben P, Baumeister W, Förster F. Structural disorder and its role in proteasomal degradation. FEBS Lett 2015; 589:2552-60. [PMID: 26226424 DOI: 10.1016/j.febslet.2015.07.034] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 07/17/2015] [Accepted: 07/17/2015] [Indexed: 10/23/2022]
Abstract
The ubiquitin proteasome system is responsible for the controlled degradation of a vast number of intracellular proteins. It targets misfolded or otherwise aberrant proteins as well as proteins no longer needed at a given point in time. The 26S proteasome is a large macromolecular machine comprising 33 distinct subunits as well as a number of transiently associating cofactors. Being essentially a non-specific protease, specificity is conferred by the ubiquitin system, which selects and marks substrates for degradation. Here, we review our current understanding of the structure and function of the 26S proteasome; in doing so we highlight the role of disordered protein regions. Disordered segments in substrates promote their degradation, whereas low complexity regions prevent their proteolysis. In the 26S proteasome itself a main role of disordered segments seems to be rendering the ubiquitin receptors mobile, possibly supporting recruitment of polyubiquitylated substrates. Thus, these structural features of substrates as well as of the 26S proteasome itself likely play important roles at different stages of the protein degradation process.
Collapse
Affiliation(s)
- Antje Aufderheide
- Max-Planck Institute of Biochemistry, Department of Molecular Structural Biology, Martinsried, Germany
| | - Pia Unverdorben
- Max-Planck Institute of Biochemistry, Department of Molecular Structural Biology, Martinsried, Germany
| | - Wolfgang Baumeister
- Max-Planck Institute of Biochemistry, Department of Molecular Structural Biology, Martinsried, Germany.
| | - Friedrich Förster
- Max-Planck Institute of Biochemistry, Department of Molecular Structural Biology, Martinsried, Germany.
| |
Collapse
|
27
|
Structural characterization of the interaction of Ubp6 with the 26S proteasome. Proc Natl Acad Sci U S A 2015; 112:8626-31. [PMID: 26130806 DOI: 10.1073/pnas.1510449112] [Citation(s) in RCA: 91] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In eukaryotic cells, the 26S proteasome is responsible for the regulated degradation of intracellular proteins. Several cofactors interact transiently with this large macromolecular machine and modulate its function. The deubiquitylating enzyme ubiquitin C-terminal hydrolase 6 [Ubp6; ubiquitin-specific protease (USP) 14 in mammals] is the most abundant proteasome-interacting protein and has multiple roles in regulating proteasome function. Here, we investigate the structural basis of the interaction between Ubp6 and the 26S proteasome in the presence and absence of the inhibitor ubiquitin aldehyde. To this end we have used single-particle electron cryomicroscopy in combination with cross-linking and mass spectrometry. Ubp6 binds to the regulatory particle non-ATPase (Rpn) 1 via its N-terminal ubiquitin-like domain, whereas its catalytic USP domain is positioned variably. Addition of ubiquitin aldehyde stabilizes the binding of the USP domain in a position where it bridges the proteasome subunits Rpn1 and the regulatory particle triple-A ATPase (Rpt) 1. The USP domain binds to Rpt1 in the immediate vicinity of the Ubp6 active site, which may effect its activation. The catalytic triad is positioned in proximity to the mouth of the ATPase module and to the deubiquitylating enzyme Rpn11, strongly implying their functional linkage. On the proteasome side, binding of Ubp6 favors conformational switching of the 26S proteasome into an intermediate-energy conformational state, in particular upon the addition of ubiquitin aldehyde. This modulation of the conformational space of the 26S proteasome by Ubp6 explains the effects of Ubp6 on the kinetics of proteasomal degradation.
Collapse
|
28
|
Kaake RM, Kao A, Yu C, Huang L. Characterizing the dynamics of proteasome complexes by proteomics approaches. Antioxid Redox Signal 2014; 21:2444-56. [PMID: 24423446 PMCID: PMC4241863 DOI: 10.1089/ars.2013.5815] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
SIGNIFICANCE The proteasome is the degradation machine of the ubiquitin-proteasome system, which is critical in controlling many essential biological processes. Aberrant regulation of proteasome-dependent protein degradation can lead to various human diseases, and general proteasome inhibitors have shown efficacy for cancer treatments. Though clinically effective, current proteasome inhibitors have detrimental side effects and, thus, better therapeutic strategies targeting proteasomes are needed. Therefore, a comprehensive characterization of proteasome complexes will provide the molecular details that are essential for developing new and improved drugs. RECENT ADVANCES New mass spectrometry (MS)-based proteomics approaches have been developed to study protein interaction networks and structural topologies of proteasome complexes. The results have helped define the dynamic proteomes of proteasome complexes, thus providing new insights into the mechanisms underlying proteasome function and regulation. CRITICAL ISSUES The proteasome exists as heterogeneous populations in tissues/cells, and its proteome is highly dynamic and complex. In addition, proteasome complexes are regulated by various mechanisms under different physiological conditions. Consequently, complete proteomic profiling of proteasome complexes remains a major challenge for the field. FUTURE DIRECTIONS We expect that proteomic methodologies enabling full characterization of proteasome complexes will continue to evolve. Further advances in MS instrumentation and protein separation techniques will be needed to facilitate the detailed proteomic analysis of low-abundance components and subpopulations of proteasome complexes. The results will help us understand proteasome biology as well as provide new therapeutic targets for disease diagnostics and treatment.
Collapse
Affiliation(s)
- Robyn M Kaake
- Department of Physiology and Biophysics, University of California , Irvine, Irvine, California
| | | | | | | |
Collapse
|
29
|
The amazing ubiquitin-proteasome system: structural components and implication in aging. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2014; 314:171-237. [PMID: 25619718 DOI: 10.1016/bs.ircmb.2014.09.002] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Proteome quality control (PQC) is critical for the maintenance of cellular functionality and it is assured by the curating activity of the proteostasis network (PN). PN is constituted of several complex protein machines that under conditions of proteome instability aim to, firstly identify, and then, either rescue or degrade nonnative polypeptides. Central to the PN functionality is the ubiquitin-proteasome system (UPS) which is composed from the ubiquitin-conjugating enzymes and the proteasome; the latter is a sophisticated multi-subunit molecular machine that functions in a bimodal way as it degrades both short-lived ubiquitinated normal proteins and nonfunctional polypeptides. UPS is also involved in PQC of the nucleus, the endoplasmic reticulum and the mitochondria and it also interacts with the other main cellular degradation axis, namely the autophagy-lysosome system. UPS functionality is optimum in the young organism but it is gradually compromised during aging resulting in increasing proteotoxic stress; these effects correlate not only with aging but also with most age-related diseases. Herein, we present a synopsis of the UPS components and of their functional alterations during cellular senescence or in vivo aging. We propose that mild UPS activation in the young organism will, likely, promote antiaging effects and/or suppress age-related diseases.
Collapse
|
30
|
Screening of cellular proteins that interact with the classical swine fever virus non-structural protein 5A by yeast two-hybrid analysis. J Biosci 2014; 39:63-74. [PMID: 24499791 DOI: 10.1007/s12038-013-9411-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Classical swine fever virus (CSFV), the pathogen of classical swine fever (CSF), causes severe hemorrhagic fever and vascular necrosis in domestic pigs and wild boar. A large number of evidence has proven that non-structural 5A (NS5A) is not only a very important part of viral replication complex, but also can regulate host cell's function; however, the underlying mechanisms remain poorly understood. In the current study, aiming to find more clues in understanding the molecular mechanisms of CSFV NS5A's function, the yeast two-hybrid (Y2H) system was adopted to screen for CSFV NS5A interactive proteins in the cDNA library of the swine umbilical vein endothelial cell (SUVEC). Alignment with the NCBI database revealed 16 interactive proteins: DDX5, PSMC3, NAV1, PHF5A, GNB2L1, CSDE1, HSPA8, BRMS1, PPP2R3C, AIP, TMED10, POLR1C, TMEM70, METAP2, CHORDC1 and COPS6. These proteins are mostly related to gene transcription, protein folding, protein degradation and metabolism. The interactions detected by the Y2H system should be considered as preliminary results. Since identifying novel pathways and host targets, which play essential roles during infection, may provide potential targets for therapeutic development. The finding of proteins obtained from the SUVEC cDNA library that interact with the CSFV NS5A protein provide valuable information for better understanding the interactions between this viral protein and the host target proteins.
Collapse
|
31
|
Fabre B, Lambour T, Bouyssié D, Menneteau T, Monsarrat B, Burlet-Schiltz O, Bousquet-Dubouch MP. Comparison of label-free quantification methods for the determination of protein complexes subunits stoichiometry. EUPA OPEN PROTEOMICS 2014. [DOI: 10.1016/j.euprot.2014.06.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
32
|
Chaperoning proteins for destruction: diverse roles of Hsp70 chaperones and their co-chaperones in targeting misfolded proteins to the proteasome. Biomolecules 2014; 4:704-24. [PMID: 25036888 PMCID: PMC4192669 DOI: 10.3390/biom4030704] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Revised: 05/31/2014] [Accepted: 06/24/2014] [Indexed: 01/04/2023] Open
Abstract
Molecular chaperones were originally discovered as heat shock-induced proteins that facilitate proper folding of proteins with non-native conformations. While the function of chaperones in protein folding has been well documented over the last four decades, more recent studies have shown that chaperones are also necessary for the clearance of terminally misfolded proteins by the Ub-proteasome system. In this capacity, chaperones protect misfolded degradation substrates from spontaneous aggregation, facilitate their recognition by the Ub ligation machinery and finally shuttle the ubiquitylated substrates to the proteasome. The physiological importance of these functions is manifested by inefficient proteasomal degradation and the accumulation of protein aggregates during ageing or in certain neurodegenerative diseases, when chaperone levels decline. In this review, we focus on the diverse roles of stress-induced chaperones in targeting misfolded proteins to the proteasome and the consequences of their compromised activity. We further discuss the implications of these findings to the identification of new therapeutic targets for the treatment of amyloid diseases.
Collapse
|
33
|
Chondrogianni N, Sakellari M, Lefaki M, Papaevgeniou N, Gonos ES. Proteasome activation delays aging in vitro and in vivo. Free Radic Biol Med 2014; 71:303-320. [PMID: 24681338 DOI: 10.1016/j.freeradbiomed.2014.03.031] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Revised: 03/18/2014] [Accepted: 03/18/2014] [Indexed: 02/02/2023]
Abstract
Aging is a natural biological process that is characterized by a progressive accumulation of macromolecular damage. In the proteome, aging is accompanied by decreased protein homeostasis and function of the major cellular proteolytic systems, leading to the accumulation of unfolded, misfolded, or aggregated proteins. In particular, the proteasome is responsible for the removal of normal as well as damaged or misfolded proteins. Extensive work during the past several years has clearly demonstrated that proteasome activation by either genetic means or use of compounds significantly retards aging. Importantly, this represents a common feature across evolution, thereby suggesting proteasome activation to be an evolutionarily conserved mechanism of aging and longevity regulation. This review article reports on the means of function of these proteasome activators and how they regulate aging in various species.
Collapse
Affiliation(s)
- Niki Chondrogianni
- National Hellenic Research Foundation, Institute of Biology, Medicinal Chemistry, and Biotechnology, 116 35 Athens, Greece.
| | - Marianthi Sakellari
- National Hellenic Research Foundation, Institute of Biology, Medicinal Chemistry, and Biotechnology, 116 35 Athens, Greece; Örebro University Medical School, Örebro, Sweden
| | - Maria Lefaki
- National Hellenic Research Foundation, Institute of Biology, Medicinal Chemistry, and Biotechnology, 116 35 Athens, Greece
| | - Nikoletta Papaevgeniou
- National Hellenic Research Foundation, Institute of Biology, Medicinal Chemistry, and Biotechnology, 116 35 Athens, Greece
| | - Efstathios S Gonos
- National Hellenic Research Foundation, Institute of Biology, Medicinal Chemistry, and Biotechnology, 116 35 Athens, Greece; Örebro University Medical School, Örebro, Sweden
| |
Collapse
|
34
|
Fabre B, Lambour T, Garrigues L, Ducoux-Petit M, Amalric F, Monsarrat B, Burlet-Schiltz O, Bousquet-Dubouch MP. Label-Free Quantitative Proteomics Reveals the Dynamics of Proteasome Complexes Composition and Stoichiometry in a Wide Range of Human Cell Lines. J Proteome Res 2014; 13:3027-37. [DOI: 10.1021/pr500193k] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Bertrand Fabre
- CNRS; IPBS (Institut de Pharmacologie et de Biologie Structurale); 205 route de Narbonne, F-31077 Toulouse, France
- Université de Toulouse; UPS; IPBS; F-31077 Toulouse, France
| | - Thomas Lambour
- CNRS; IPBS (Institut de Pharmacologie et de Biologie Structurale); 205 route de Narbonne, F-31077 Toulouse, France
- Université de Toulouse; UPS; IPBS; F-31077 Toulouse, France
| | - Luc Garrigues
- CNRS; IPBS (Institut de Pharmacologie et de Biologie Structurale); 205 route de Narbonne, F-31077 Toulouse, France
- Université de Toulouse; UPS; IPBS; F-31077 Toulouse, France
| | - Manuelle Ducoux-Petit
- CNRS; IPBS (Institut de Pharmacologie et de Biologie Structurale); 205 route de Narbonne, F-31077 Toulouse, France
- Université de Toulouse; UPS; IPBS; F-31077 Toulouse, France
| | - François Amalric
- CNRS; IPBS (Institut de Pharmacologie et de Biologie Structurale); 205 route de Narbonne, F-31077 Toulouse, France
- Université de Toulouse; UPS; IPBS; F-31077 Toulouse, France
| | - Bernard Monsarrat
- CNRS; IPBS (Institut de Pharmacologie et de Biologie Structurale); 205 route de Narbonne, F-31077 Toulouse, France
- Université de Toulouse; UPS; IPBS; F-31077 Toulouse, France
| | - Odile Burlet-Schiltz
- CNRS; IPBS (Institut de Pharmacologie et de Biologie Structurale); 205 route de Narbonne, F-31077 Toulouse, France
- Université de Toulouse; UPS; IPBS; F-31077 Toulouse, France
| | - Marie-Pierre Bousquet-Dubouch
- CNRS; IPBS (Institut de Pharmacologie et de Biologie Structurale); 205 route de Narbonne, F-31077 Toulouse, France
- Université de Toulouse; UPS; IPBS; F-31077 Toulouse, France
| |
Collapse
|
35
|
Deep classification of a large cryo-EM dataset defines the conformational landscape of the 26S proteasome. Proc Natl Acad Sci U S A 2014; 111:5544-9. [PMID: 24706844 DOI: 10.1073/pnas.1403409111] [Citation(s) in RCA: 151] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The 26S proteasome is a 2.5 MDa molecular machine that executes the degradation of substrates of the ubiquitin-proteasome pathway. The molecular architecture of the 26S proteasome was recently established by cryo-EM approaches. For a detailed understanding of the sequence of events from the initial binding of polyubiquitylated substrates to the translocation into the proteolytic core complex, it is necessary to move beyond static structures and characterize the conformational landscape of the 26S proteasome. To this end we have subjected a large cryo-EM dataset acquired in the presence of ATP and ATP-γS to a deep classification procedure, which deconvolutes coexisting conformational states. Highly variable regions, such as the density assigned to the largest subunit, Rpn1, are now well resolved and rendered interpretable. Our analysis reveals the existence of three major conformations: in addition to the previously described ATP-hydrolyzing (ATPh) and ATP-γS conformations, an intermediate state has been found. Its AAA-ATPase module adopts essentially the same topology that is observed in the ATPh conformation, whereas the lid is more similar to the ATP-γS bound state. Based on the conformational ensemble of the 26S proteasome in solution, we propose a mechanistic model for substrate recognition, commitment, deubiquitylation, and translocation into the core particle.
Collapse
|
36
|
The ubiquitin proteasome system in Caenorhabditis elegans and its regulation. Redox Biol 2014; 2:333-47. [PMID: 24563851 PMCID: PMC3926112 DOI: 10.1016/j.redox.2014.01.007] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 01/08/2014] [Accepted: 01/10/2014] [Indexed: 11/20/2022] Open
Abstract
Protein degradation constitutes a major cellular function that is responsible for maintenance of the normal cellular physiology either through the degradation of normal proteins or through the elimination of damaged proteins. The Ubiquitin–Proteasome System (UPS)1 is one of the main proteolytic systems that orchestrate protein degradation. Given that up- and down- regulation of the UPS system has been shown to occur in various normal (such as ageing) and pathological (such as neurodegenerative diseases) processes, the exogenous modulation of the UPS function and activity holds promise of (a) developing new therapeutic interventions against various diseases and (b) establishing strategies to maintain cellular homeostasis. Since the proteasome genes are evolutionarily conserved, their role can be dissected in simple model organisms, such as the nematode, Caenorhabditis elegans. In this review, we survey findings on the redox regulation of the UPS in C. elegans showing that the nematode is an instrumental tool in the identification of major players in the UPS pathway. Moreover, we specifically discuss UPS-related genes that have been modulated in the nematode and in human cells and have resulted in similar effects thus further exhibiting the value of this model in the study of the UPS. UPS is one of the main proteolytic systems that orchestrate protein degradation. Proteasome function can be dissected in Caenorhabditis elegans. Nematodes can be used in the identification of major players in the UPS pathway.
Collapse
|
37
|
Berko D, Herkon O, Braunstein I, Isakov E, David Y, Ziv T, Navon A, Stanhill A. Inherent asymmetry in the 26S proteasome is defined by the ubiquitin receptor RPN13. J Biol Chem 2014; 289:5609-18. [PMID: 24429290 DOI: 10.1074/jbc.m113.509380] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The 26S double-capped proteasome is assembled in a hierarchic event that is orchestrated by dedicated set of chaperons. To date, all stoichiometric subunits are considered to be present in equal ratios, thus providing symmetry to the double-capped complex. Here, we show that although the vast majority (if not all) of the double-capped 26S proteasomes, both 19S complexes, contain the ubiquitin receptor Rpn10/S5a, only one of these 19S particles contains the additional ubiquitin receptor Rpn13, thereby defining asymmetry in the 26S proteasome. These results were validated in yeast and mammals, utilizing biochemical and unbiased AQUA-MS methodologies. Thus, the double-capped 26S proteasomes are asymmetric in their polyubiquitin binding capacity. Our data point to a potential new role for ubiquitin receptors as directionality factors that may participate in the prevention of simultaneous substrates translocation into the 20S from both 19S caps.
Collapse
Affiliation(s)
- Dikla Berko
- From the Department of Biochemistry, The Rappaport Family Institute for Research in the Medical Sciences, Technion-Israel Institute of Technology, Haifa 31096, Israel
| | | | | | | | | | | | | | | |
Collapse
|
38
|
Webb B, Lasker K, Velázquez-Muriel J, Schneidman-Duhovny D, Pellarin R, Bonomi M, Greenberg C, Raveh B, Tjioe E, Russel D, Sali A. Modeling of proteins and their assemblies with the Integrative Modeling Platform. Methods Mol Biol 2014; 1091:277-95. [PMID: 24203340 DOI: 10.1007/978-1-62703-691-7_20] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
To understand the workings of the living cell, we need to characterize protein assemblies that constitute the cell (for example, the ribosome, 26S proteasome, and the nuclear pore complex). A reliable high-resolution structural characterization of these assemblies is frequently beyond the reach of current experimental methods, such as X-ray crystallography, NMR spectroscopy, electron microscopy, footprinting, chemical cross-linking, FRET spectroscopy, small angle X-ray scattering, and proteomics. However, the information garnered from different methods can be combined and used to build models of the assembly structures that are consistent with all of the available datasets, and therefore more accurate, precise, and complete. Here, we describe a protocol for this integration, whereby the information is converted to a set of spatial restraints and a variety of optimization procedures can be used to generate models that satisfy the restraints as well as possible. These generated models can then potentially inform about the precision and accuracy of structure determination, the accuracy of the input datasets, and further data generation. We also demonstrate the Integrative Modeling Platform (IMP) software, which provides the necessary computational framework to implement this protocol, and several applications for specific use cases.
Collapse
Affiliation(s)
- Benjamin Webb
- Department of Bioengineering and Therapeutic Sciences, Department of Pharmaceutical Chemistry, and California Institute for Quanstitative Biosciences (QB3), University of California San Francisco, San Francisco, CA, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Sridhar S, Bhat G, Guruprasad K. Analysis of bortezomib inhibitor docked within the catalytic subunits of the Plasmodium falciparum 20S proteasome. SPRINGERPLUS 2013; 2:566. [PMID: 24255860 PMCID: PMC3825223 DOI: 10.1186/2193-1801-2-566] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Accepted: 10/11/2013] [Indexed: 11/18/2022]
Abstract
The three-dimensional fold of Plasmodium falciparum (Pf) 20S proteasome is similar to yeast Saccharomyces cerevisiae 20S proteasome. The twenty eight subunits complex corresponding to two copies of seven distinct α and seven distinct β subunits shares >35% sequence identity with equivalent subunits of the yeast 20S proteasome. Bortezomib (Velcade®) - a known inhibitor of the three catalytic subunits; β1, β2, β5 of the yeast 20S proteasome can bind in the equivalent subunits of the Pf 20S proteasome and is in agreement with experimental results. The model defines the binding mode of the bortezomib inhibitor within the catalytic subunits of the Pf 20S proteasome and provides the structural basis for the design of Pf 20S proteasome-specific inhibitors. The substitutions associated within the catalytic subunits of Pf 20S proteasome relative to yeast 20S proteasome; Thr21-Ser, Thr22-Ser, Thr31-Ser, Thr35-Asn, Ala49-Ser (in β1 subunit), Ser20-Ala, Gln22-Glu (β2) and Thr21-Ser, Ala22-Met, Gln53-Leu (β5) may influence the relative caspase-like, tryptic-like and chymotryptic-like activities of the Pf 20S proteasome. The plasmodia-specific 'large' insert comprising fifty four amino acid residues (in β1 subunit) of the Pf 20S proteasome is distant from the catalytic sites.
Collapse
Affiliation(s)
- Settu Sridhar
- Bioinformatics, Centre for Cellular and Molecular Biology, Hyderabad, 500 007 India
| | - Gayathri Bhat
- Bioinformatics, Centre for Cellular and Molecular Biology, Hyderabad, 500 007 India
| | - Kunchur Guruprasad
- Bioinformatics, Centre for Cellular and Molecular Biology, Hyderabad, 500 007 India
| |
Collapse
|
40
|
Sparks A, Dayal S, Das J, Robertson P, Menendez S, Saville MK. The degradation of p53 and its major E3 ligase Mdm2 is differentially dependent on the proteasomal ubiquitin receptor S5a. Oncogene 2013; 33:4685-96. [PMID: 24121268 PMCID: PMC4051618 DOI: 10.1038/onc.2013.413] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Revised: 07/10/2013] [Accepted: 08/09/2013] [Indexed: 01/24/2023]
Abstract
p53 and its major E3 ligase Mdm2 are both ubiquitinated and targeted to the proteasome for degradation. Despite the importance of this in regulating the p53 pathway, little is known about the mechanisms of proteasomal recognition of ubiquitinated p53 and Mdm2. In this study, we show that knockdown of the proteasomal ubiquitin receptor S5a/PSMD4/Rpn10 inhibits p53 protein degradation and results in the accumulation of ubiquitinated p53. Overexpression of a dominant-negative deletion of S5a lacking its ubiquitin-interacting motifs (UIM)s, but which can be incorporated into the proteasome, also causes the stabilization of p53. Furthermore, small-interferring RNA (siRNA) rescue experiments confirm that the UIMs of S5a are required for the maintenance of low p53 levels. These observations indicate that S5a participates in the recognition of ubiquitinated p53 by the proteasome. In contrast, targeting S5a has no effect on the rate of degradation of Mdm2, indicating that proteasomal recognition of Mdm2 can be mediated by an S5a-independent pathway. S5a knockdown results in an increase in the transcriptional activity of p53. The selective stabilization of p53 and not Mdm2 provides a mechanism for p53 activation. Depletion of S5a causes a p53-dependent decrease in cell proliferation, demonstrating that p53 can have a dominant role in the response to targeting S5a. This study provides evidence for alternative pathways of proteasomal recognition of p53 and Mdm2. Differences in recognition by the proteasome could provide a means to modulate the relative stability of p53 and Mdm2 in response to cellular signals. In addition, they could be exploited for p53-activating therapies. This work shows that the degradation of proteins by the proteasome can be selectively dependent on S5a in human cells, and that this selectivity can extend to an E3 ubiquitin ligase and its substrate.
Collapse
Affiliation(s)
- A Sparks
- Division of Cancer Research, Medical Research Institute, Jacqui Wood Cancer Centre, Ninewells Hospital and Medical School, University of Dundee, Dundee, UK
| | - S Dayal
- Division of Cancer Research, Medical Research Institute, Jacqui Wood Cancer Centre, Ninewells Hospital and Medical School, University of Dundee, Dundee, UK
| | - J Das
- Division of Cancer Research, Medical Research Institute, Jacqui Wood Cancer Centre, Ninewells Hospital and Medical School, University of Dundee, Dundee, UK
| | - P Robertson
- Division of Molecular Medicine, College of Life Sciences, University of Dundee, Dundee, UK
| | - S Menendez
- MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh, UK
| | - M K Saville
- Division of Cancer Research, Medical Research Institute, Jacqui Wood Cancer Centre, Ninewells Hospital and Medical School, University of Dundee, Dundee, UK
| |
Collapse
|
41
|
Tsakiri EN, Sykiotis GP, Papassideri IS, Terpos E, Dimopoulos MA, Gorgoulis VG, Bohmann D, Trougakos IP. Proteasome dysfunction in Drosophila signals to an Nrf2-dependent regulatory circuit aiming to restore proteostasis and prevent premature aging. Aging Cell 2013; 12:802-13. [PMID: 23738891 DOI: 10.1111/acel.12111] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/22/2013] [Indexed: 11/30/2022] Open
Abstract
The ubiquitin-proteasome system is central to the regulation of cellular proteostasis. Nevertheless, the impact of in vivo proteasome dysfunction on the proteostasis networks and the aging processes remains poorly understood. We found that RNAi-mediated knockdown of 20S proteasome subunits in Drosophila melanogaster resulted in larval lethality. We therefore studied the molecular effects of proteasome dysfunction in adult flies by developing a model of dose-dependent pharmacological proteasome inhibition. Impaired proteasome function promoted several 'old-age' phenotypes and markedly reduced flies' lifespan. In young somatic tissues and in gonads of all ages, loss of proteasome activity induced higher expression levels and assembly rates of proteasome subunits. Proteasome dysfunction was signaled to the proteostasis network by reactive oxygen species that originated from malfunctioning mitochondria and triggered an Nrf2-dependent upregulation of the proteasome subunits. RNAi-mediated Nrf2 knockdown reduced proteasome activities, flies' resistance to stress, as well as longevity. Conversely, inducible activation of Nrf2 in transgenic flies upregulated basal proteasome expression and activity independently of age and conferred resistance to proteotoxic stress. Interestingly, prolonged Nrf2 overexpression reduced longevity, indicating that excessive activation of the proteostasis pathways can be detrimental. Our in vivo studies add new knowledge on the proteotoxic stress-related regulation of the proteostasis networks in higher metazoans. Proteasome dysfunction triggers the activation of an Nrf2-dependent tissue- and age-specific regulatory circuit aiming to adjust the cellular proteasome activity according to temporal and/or spatial proteolytic demands. Prolonged deregulation of this proteostasis circuit accelerates aging.
Collapse
Affiliation(s)
- Eleni N. Tsakiri
- Department of Cell Biology and Biophysics; Faculty of Biology; University of Athens; Panepistimiopolis; Athens 15784; Greece
| | - Gerasimos P. Sykiotis
- Division of Endocrinology; Department of Internal Medicine; University of Patras Medical School; Patras 26500; Greece
| | - Issidora S. Papassideri
- Department of Cell Biology and Biophysics; Faculty of Biology; University of Athens; Panepistimiopolis; Athens 15784; Greece
| | - Evangelos Terpos
- Department of Clinical Therapeutics; School of Medicine; University of Athens; Athens 11528; Greece
| | - Meletios A. Dimopoulos
- Department of Clinical Therapeutics; School of Medicine; University of Athens; Athens 11528; Greece
| | | | - Dirk Bohmann
- Department of Biomedical Genetics; University of Rochester Medical Center; Rochester; NY 14642; USA
| | - Ioannis P. Trougakos
- Department of Cell Biology and Biophysics; Faculty of Biology; University of Athens; Panepistimiopolis; Athens 15784; Greece
| |
Collapse
|
42
|
Falaschetti CA, Paunesku T, Kurepa J, Nanavati D, Chou SS, De M, Song M, Jang JT, Wu A, Dravid VP, Cheon J, Smalle J, Woloschak GE. Negatively charged metal oxide nanoparticles interact with the 20S proteasome and differentially modulate its biologic functional effects. ACS NANO 2013; 7:7759-7772. [PMID: 23930940 PMCID: PMC3946455 DOI: 10.1021/nn402416h] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The multicatalytic ubiquitin-proteasome system (UPS) carries out proteolysis in a highly orchestrated way and regulates a large number of cellular processes. Deregulation of the UPS in many disorders has been documented. In some cases, such as carcinogenesis, elevated proteasome activity has been implicated in disease development, while the etiology of other diseases, such as neurodegeneration, includes decreased UPS activity. Therefore, agents that alter proteasome activity could suppress as well as enhance a multitude of diseases. Metal oxide nanoparticles, often developed as diagnostic tools, have not previously been tested as modulators of proteasome activity. Here, several types of metal oxide nanoparticles were found to adsorb to the proteasome and show variable preferential binding for particular proteasome subunits with several peptide binding "hotspots" possible. These interactions depend on the size, charge, and concentration of the nanoparticles and affect proteasome activity in a time-dependent manner. Should metal oxide nanoparticles increase proteasome activity in cells, as they do in vitro, unintended effects related to changes in proteasome function can be expected.
Collapse
Affiliation(s)
- Christine A. Falaschetti
- Northwestern University, Feinberg School of Medicine, Department of Radiation Oncology, Chicago, IL, United States
| | - Tatjana Paunesku
- Northwestern University, Feinberg School of Medicine, Department of Radiation Oncology, Chicago, IL, United States
| | - Jasmina Kurepa
- University of Kentucky, Department of Plant and Soil Sciences, Lexington, KY, United States
| | - Dhaval Nanavati
- Northwestern University, Chemistry of Life Processes Institute, Proteomics Core, Evanston, IL, United States
| | - Stanley S. Chou
- Northwestern University, Department of Materials Science and Engineering, Evanston, IL, United States
| | - Mrinmoy De
- Northwestern University, Department of Materials Science and Engineering, Evanston, IL, United States
| | - MinHa Song
- Yonsei University, Department of Chemistry, Seoul, South Korea
| | - Jung-tak Jang
- Yonsei University, Department of Chemistry, Seoul, South Korea
| | - Aiguo Wu
- Ningbo Institute of Materials Technology & Engineering, Division of Functional Materials and Nano-Devices, Ningbo, China
| | - Vinayak P. Dravid
- Northwestern University, Department of Materials Science and Engineering, Evanston, IL, United States
| | - Jinwoo Cheon
- Yonsei University, Department of Chemistry, Seoul, South Korea
| | - Jan Smalle
- University of Kentucky, Department of Plant and Soil Sciences, Lexington, KY, United States
| | - Gayle E. Woloschak
- Northwestern University, Feinberg School of Medicine, Department of Radiation Oncology, Chicago, IL, United States
| |
Collapse
|
43
|
Förster F, Unverdorben P, Śledź P, Baumeister W. Unveiling the Long-Held Secrets of the 26S Proteasome. Structure 2013; 21:1551-62. [DOI: 10.1016/j.str.2013.08.010] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Revised: 08/15/2013] [Accepted: 08/16/2013] [Indexed: 01/23/2023]
|
44
|
Conformational switching of the 26S proteasome enables substrate degradation. Nat Struct Mol Biol 2013; 20:781-8. [PMID: 23770819 PMCID: PMC3712289 DOI: 10.1038/nsmb.2616] [Citation(s) in RCA: 199] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Accepted: 05/14/2013] [Indexed: 02/07/2023]
Abstract
The 26S proteasome is the major eukaryotic ATP-dependent protease, responsible for regulating the proteome through degradation of ubiquitin-tagged substrates. Its regulatory particle, containing the heterohexameric AAA+ ATPase motor and the essential deubiquitinase Rpn11, recognizes substrates, removes their ubiquitin chains, and translocates them into the associated peptidase after unfolding, but detailed mechanisms remain unknown. Here we present the first structure of the 26S proteasome from S. cerevisiae during substrate degradation, showing that the regulatory particle switches from a pre-engaged to a translocation-competent conformation. This conformation is characterized by a rearranged ATPase ring with uniform subunit interfaces, a widened central channel coaxially aligned with the peptidase, and a spiral orientation of pore loops that suggests a rapid progression of ATP-hydrolysis events around the ring. Importantly, Rpn11 moves from an occluded position to directly above the central pore, facilitating substrate deubiquitination concomitant with translocation.
Collapse
|
45
|
Tsakiri EN, Sykiotis GP, Papassideri IS, Gorgoulis VG, Bohmann D, Trougakos IP. Differential regulation of proteasome functionality in reproductive vs. somatic tissues of Drosophila during aging or oxidative stress. FASEB J 2013; 27:2407-20. [PMID: 23457214 PMCID: PMC4050428 DOI: 10.1096/fj.12-221408] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Accepted: 02/21/2013] [Indexed: 12/29/2022]
Abstract
Proteasome is central to proteostasis maintenance, as it degrades both normal and damaged proteins. Herein, we undertook a detailed analysis of proteasome regulation in the in vivo setting of Drosophila melanogaster. We report that a major hallmark of somatic tissues of aging flies is the gradual accumulation of ubiquitinated and carbonylated proteins; these effects correlated with a ~50% reduction of proteasome expression and catalytic activities. In contrast, gonads of aging flies were relatively free of proteome oxidative damage and maintained substantial proteasome expression levels and highly active proteasomes. Moreover, gonads of young flies were found to possess more abundant and more active proteasomes than somatic tissues. Exposure of flies to oxidants induced higher proteasome activities specifically in the gonads, which were, independently of age, more resistant than soma to oxidative challenge and, as analyses in reporter transgenic flies showed, retained functional antioxidant responses. Finally, inducible Nrf2 activation in transgenic flies promoted youthful proteasome expression levels in the aged soma, suggesting that age-dependent Nrf2 dysfunction is causative of decreasing somatic proteasome expression during aging. The higher investment in proteostasis maintenance in the gonads plausibly facilitates proteome stability across generations; it also provides evidence in support of the trade-off theories of aging.
Collapse
Affiliation(s)
- Eleni N. Tsakiri
- Department of Cell Biology and Biophysics, Faculty of Biology, University of Athens, Panepistimiopolis, Athens, Greece
| | - Gerasimos P. Sykiotis
- Division of Endocrinology, Department of Internal Medicine, University of Patras Medical School, Patras, Greece
| | - Issidora S. Papassideri
- Department of Cell Biology and Biophysics, Faculty of Biology, University of Athens, Panepistimiopolis, Athens, Greece
| | - Vassilis G. Gorgoulis
- Department of Histology and Embryology, School of Medicine, University of Athens, Athens, Greece; and
| | - Dirk Bohmann
- Department of Biomedical Genetics, University of Rochester Medical Center, Rochester, New York, USA
| | - Ioannis P. Trougakos
- Department of Cell Biology and Biophysics, Faculty of Biology, University of Athens, Panepistimiopolis, Athens, Greece
| |
Collapse
|
46
|
Śledź P, Unverdorben P, Beck F, Pfeifer G, Schweitzer A, Förster F, Baumeister W. Structure of the 26S proteasome with ATP-γS bound provides insights into the mechanism of nucleotide-dependent substrate translocation. Proc Natl Acad Sci U S A 2013; 110:7264-9. [PMID: 23589842 PMCID: PMC3645540 DOI: 10.1073/pnas.1305782110] [Citation(s) in RCA: 128] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The 26S proteasome is a 2.5-MDa, ATP-dependent multisubunit proteolytic complex that processively destroys proteins carrying a degradation signal. The proteasomal ATPase heterohexamer is a key module of the 19S regulatory particle; it unfolds substrates and translocates them into the 20S core particle where degradation takes place. We used cryoelectron microscopy single-particle analysis to obtain insights into the structural changes of 26S proteasome upon the binding and hydrolysis of ATP. The ATPase ring adopts at least two distinct helical staircase conformations dependent on the nucleotide state. The transition from the conformation observed in the presence of ATP to the predominant conformation in the presence of ATP-γS induces a sliding motion of the ATPase ring over the 20S core particle ring leading to an alignment of the translocation channels of the ATPase and the core particle gate, a conformational state likely to facilitate substrate translocation. Two types of intersubunit modules formed by the large ATPase domain of one ATPase subunit and the small ATPase domain of its neighbor exist. They resemble the contacts observed in the crystal structures of ClpX and proteasome-activating nucleotidase, respectively. The ClpX-like contacts are positioned consecutively and give rise to helical shape in the hexamer, whereas the proteasome-activating nucleotidase-like contact is required to close the ring. Conformational switching between these forms allows adopting different helical conformations in different nucleotide states. We postulate that ATP hydrolysis by the regulatory particle ATPase (Rpt) 5 subunit initiates a cascade of conformational changes, leading to pulling of the substrate, which is primarily executed by Rpt1, Rpt2, and Rpt6.
Collapse
Affiliation(s)
- Paweł Śledź
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Pia Unverdorben
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Florian Beck
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Günter Pfeifer
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Andreas Schweitzer
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Friedrich Förster
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Wolfgang Baumeister
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| |
Collapse
|
47
|
Abstract
The eukaryotic ubiquitin-proteasome system is responsible for most aspects of regulatory and quality-control protein degradation in cells. Its substrates, which are usually modified by polymers of ubiquitin, are ultimately degraded by the 26S proteasome. This 2.6-MDa protein complex is separated into a barrel-shaped proteolytic 20S core particle (CP) of 28 subunits capped on one or both ends by a 19S regulatory particle (RP) comprising at least 19 subunits. The RP coordinates substrate recognition, removal of substrate polyubiquitin chains, and substrate unfolding and translocation into the CP for degradation. Although many atomic structures of the CP have been determined, the RP has resisted high-resolution analysis. Recently, however, a combination of cryo-electron microscopy, biochemical analysis, and crystal structure determination of several RP subunits has yielded a near-atomic-resolution view of much of the complex. Major new insights into chaperone-assisted proteasome assembly have also recently emerged. Here we review these novel findings.
Collapse
Affiliation(s)
- Robert J Tomko
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520, USA.
| | | |
Collapse
|
48
|
Preventive and therapeutic effects of MG132 by activating Nrf2-ARE signaling pathway on oxidative stress-induced cardiovascular and renal injury. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2013; 2013:306073. [PMID: 23533688 PMCID: PMC3606804 DOI: 10.1155/2013/306073] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Accepted: 02/14/2013] [Indexed: 12/25/2022]
Abstract
So far, cardiovascular and renal diseases have brought us not only huge economic burden but also serious society problems. Since effective therapeutic strategies are still limited, to find new methods for the prevention or therapy of these diseases is important. Oxidative stress has been found to play a critical role in the initiation and progression of cardiovascular and renal diseases. In addition, activation of nuclear-factor-E2-related-factor-2- (Nrf2-) antioxidant-responsive element (ARE) signaling pathway protects cells and tissues from oxidative damage. As a proteasomal inhibitor, MG132 was reported to activate Nrf2 expression and function, which was accompanied with significant preventive and/or therapeutic effect on cardiovascular and renal diseases under most conditions; therefore, MG132 seems to be a potentially effective drug to be used in the prevention of oxidative damage. In this paper, we will summarize the information available regarding the effect of MG132 on oxidative stress-induced cardiovascular and renal damage, especially through Nrf2-ARE signaling pathway.
Collapse
|
49
|
Tsakiri EN, Sykiotis GP, Papassideri IS, Gorgoulis VG, Bohmann D, Trougakos IP. Differential regulation of proteasome functionality in reproductive vs. somatic tissues of Drosophila during aging or oxidative stress. FASEB J 2013. [PMID: 23457214 DOI: 10.1096/fj.12–221408] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Proteasome is central to proteostasis maintenance, as it degrades both normal and damaged proteins. Herein, we undertook a detailed analysis of proteasome regulation in the in vivo setting of Drosophila melanogaster. We report that a major hallmark of somatic tissues of aging flies is the gradual accumulation of ubiquitinated and carbonylated proteins; these effects correlated with a ~50% reduction of proteasome expression and catalytic activities. In contrast, gonads of aging flies were relatively free of proteome oxidative damage and maintained substantial proteasome expression levels and highly active proteasomes. Moreover, gonads of young flies were found to possess more abundant and more active proteasomes than somatic tissues. Exposure of flies to oxidants induced higher proteasome activities specifically in the gonads, which were, independently of age, more resistant than soma to oxidative challenge and, as analyses in reporter transgenic flies showed, retained functional antioxidant responses. Finally, inducible Nrf2 activation in transgenic flies promoted youthful proteasome expression levels in the aged soma, suggesting that age-dependent Nrf2 dysfunction is causative of decreasing somatic proteasome expression during aging. The higher investment in proteostasis maintenance in the gonads plausibly facilitates proteome stability across generations; it also provides evidence in support of the trade-off theories of aging.
Collapse
Affiliation(s)
- Eleni N Tsakiri
- Department of Cell Biology and Biophysics, Faculty of Biology, University of Athens, Panepistimiopolis, Athens, Greece
| | | | | | | | | | | |
Collapse
|
50
|
Fabre B, Lambour T, Delobel J, Amalric F, Monsarrat B, Burlet-Schiltz O, Bousquet-Dubouch MP. Subcellular distribution and dynamics of active proteasome complexes unraveled by a workflow combining in vivo complex cross-linking and quantitative proteomics. Mol Cell Proteomics 2012; 12:687-99. [PMID: 23242550 DOI: 10.1074/mcp.m112.023317] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Through protein degradation, the proteasome plays fundamental roles in different cell compartments. Although the composition of the 20S catalytic core particle (CP) has been well documented, little is known about the composition and dynamics of the regulatory complexes that play a crucial role in its activity, or about how they associate with the CP in different cell compartments, different cell lines, and in response to external stimuli. Because of difficulties performing acceptable cell fractionation while maintaining complex integrity, it has been challenging to characterize proteasome complexes by proteomic approaches. Here, we report an integrated protocol, combining a cross-linking procedure on intact cells with cell fractionation, proteasome immuno-purification, and robust label-free quantitative proteomic analysis by mass spectrometry to determine the distribution and dynamics of cellular proteasome complexes in leukemic cells. Activity profiles of proteasomes were correlated fully with the composition of protein complexes and stoichiometry. Moreover, our results suggest that, at the subcellular level, proteasome function is regulated by dynamic interactions between the 20S CP and its regulatory proteins-which modulate proteasome activity, stability, localization, or substrate uptake-rather than by profound changes in 20S CP composition. Proteasome plasticity was observed both in the 20S CP and in its network of interactions following IFNγ stimulation. The fractionation protocol also revealed specific proteolytic activities and structural features of low-abundance microsomal proteasomes from U937 and KG1a cells. These could be linked to their important roles in the endoplasmic reticulum associated degradation pathway in leukemic cells.
Collapse
Affiliation(s)
- Bertrand Fabre
- CNRS/Institut de Pharmacologie et de Biologie Structurale, 205 route de Narbonne, Toulouse, France
| | | | | | | | | | | | | |
Collapse
|