1
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A Role for the Proteasome Alpha2 Subunit N-Tail in Substrate Processing. Biomolecules 2023; 13:biom13030480. [PMID: 36979414 PMCID: PMC10046698 DOI: 10.3390/biom13030480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 02/23/2023] [Accepted: 03/01/2023] [Indexed: 03/08/2023] Open
Abstract
The proteolytic active sites of the 26S proteasome are sequestered within the catalytic chamber of its 20S core particle (CP). Access to this chamber is through a narrow channel defined by the seven outer α subunits. In the resting state, the N-termini of neighboring α subunits form a gate blocking access to the channel. The attachment of the activators or regulatory particles rearranges the blocking α subunit N-termini facilitating the entry of substrates. By truncating or mutating each of the participating α N-termini, we report that whereas only a few N-termini are important for maintaining the closed gate, all seven N-termini participate in the open gate. Specifically, the open state is stabilized by a hydrogen bond between an invariant tyrosine (Y) in each subunit with a conserved aspartate (D) in its counterclockwise neighbor. The lone exception is the α1–α2 pair leaving a gap in the ring circumference. The third residue (X) of this YD(X) motif aligns with the open channel. Phenylalanine at this position in the α2 subunit comes in direct contact with the translocating substrate. Consequently, deletion of the α2 N-terminal tail attenuates proteolysis despite the appearance of an open gate state. In summary, the interlacing N-terminal YD(X) motifs regulate both the gating and translocation of the substrate.
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2
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Zeng G, Yu Q, Zhuang R, Zhu H, Shao J, Xi J, Zhang J. Recent Advances and Future Perspectives of Noncompetitive Proteasome Inhibitors. Bioorg Chem 2023; 135:106507. [PMID: 37030106 DOI: 10.1016/j.bioorg.2023.106507] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Revised: 03/17/2023] [Accepted: 03/28/2023] [Indexed: 04/03/2023]
Abstract
The proteasome regulates intracellular processes, maintains biological homeostasis, and has shown great significance in the study of various diseases, such as neurodegenerative diseases, immune-related diseases, and cancer, especially in hematologic malignancies such as multiple myeloma (MM) and mantle cell lymphoma (MCL). All clinically used proteasome inhibitors bind to the active site of the proteasome and thus exhibit a competitive mechanism. The development of resistance and intolerance during treatment drives the search for inhibitors with different mechanisms of action. In this review, we provide an overview of noncompetitive proteasome inhibitors, including their mechanisms of action, function, possible applications, and their advantages and disadvantages compared with competitive inhibitors.
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3
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Staerz SD, Jones CL, Tepe JJ. Design, Synthesis, and Biological Evaluation of Potent 20S Proteasome Activators for the Potential Treatment of α-Synucleinopathies. J Med Chem 2022; 65:6631-6642. [PMID: 35476454 DOI: 10.1021/acs.jmedchem.1c02158] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
While neurodegenerative diseases affect millions of patients worldwide, there are insufficient available therapeutics to halt or slow down the progression of these diseases. A key pathological feature of several neurodegenerative diseases is the oligomerization and aggregation of specific intrinsically disordered proteins (IDPs) creating neuronal deposits, such as Lewy bodies in Parkinson's disease. Clearance of these pathogenic, aggregation-prone IDPs is mediated by the 20S isoform of the human proteasome. Thus, enhancing the 20S proteasome-mediated proteolysis could be a very useful therapeutic pathway to prevent neurotoxicity. Here, we report the successful development of sub-microM 20S proteasome activators based on a phenothiazine scaffold. This class of compounds prevented the accumulation of pathologically relevant IDPs, such as the pathogenic A53T mutated α-synuclein, in vitro and in mammalian cell lines.
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Affiliation(s)
- Sophia D Staerz
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48823, United States
| | - Corey L Jones
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48823, United States
| | - Jetze J Tepe
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48823, United States
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4
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Fiolek TJ, Magyar CL, Wall TJ, Davies SB, Campbell MV, Savich CJ, Tepe JJ, Mosey RA. Dihydroquinazolines enhance 20S proteasome activity and induce degradation of α-synuclein, an intrinsically disordered protein associated with neurodegeneration. Bioorg Med Chem Lett 2021; 36:127821. [PMID: 33513387 DOI: 10.1016/j.bmcl.2021.127821] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 01/05/2021] [Accepted: 01/18/2021] [Indexed: 02/02/2023]
Abstract
Aggregates or oligomeric forms of many intrinsically disordered proteins (IDPs), including α-synuclein, are hallmarks of neurodegenerative diseases, like Parkinson's and Alzheimer's disease, and key contributors to their pathogenesis. Due to their disordered nature and therefore lack of defined drug-binding pockets, IDPs are difficult targets for traditional small molecule drug design and are often referred to as "undruggable". The 20S proteasome is the main protease that targets IDPs for degradation and therefore small molecule 20S proteasome enhancement presents a novel therapeutic strategy by which these undruggable IDPs could be targeted. The concept of 20S activation is still relatively new, with few potent activators having been identified thus far. Herein, we synthesized and evaluated a library of dihydroquinazoline analogues and discovered several promising new 20S proteasome activators. Further testing of top hits revealed that they can enhance 20S mediated degradation of α-synuclein, the IDP associated with Parkinson's disease.
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Affiliation(s)
- Taylor J Fiolek
- Department of Chemistry, Michigan State University, East Lansing, MI 48824, United States
| | - Christina L Magyar
- Department of Chemistry, Lake Superior State University, Sault Sainte Marie, MI 49783, United States
| | - Tyler J Wall
- Department of Chemistry, Lake Superior State University, Sault Sainte Marie, MI 49783, United States
| | - Steven B Davies
- Department of Chemistry, Lake Superior State University, Sault Sainte Marie, MI 49783, United States
| | - Molly V Campbell
- Department of Chemistry, Lake Superior State University, Sault Sainte Marie, MI 49783, United States
| | - Christopher J Savich
- Department of Chemistry, Lake Superior State University, Sault Sainte Marie, MI 49783, United States
| | - Jetze J Tepe
- Department of Chemistry, Michigan State University, East Lansing, MI 48824, United States.
| | - R Adam Mosey
- Department of Chemistry, Lake Superior State University, Sault Sainte Marie, MI 49783, United States.
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5
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Njomen E, Osmulski PA, Jones CL, Gaczynska M, Tepe JJ. Small Molecule Modulation of Proteasome Assembly. Biochemistry 2018; 57:4214-4224. [PMID: 29897236 DOI: 10.1021/acs.biochem.8b00579] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The 20S proteasome is the main protease that directly targets intrinsically disordered proteins (IDPs) for proteolytic degradation. Mutations, oxidative stress, or aging can induce the buildup of IDPs resulting in incorrect signaling or aggregation, associated with the pathogenesis of many cancers and neurodegenerative diseases. Drugs that facilitate 20S-mediated proteolysis therefore have many potential therapeutic applications. We report herein the modulation of proteasome assembly by the small molecule TCH-165, resulting in an increase in 20S levels. The increase in the level of free 20S corresponds to enhanced proteolysis of IDPs, including α-synuclein, tau, ornithine decarboxylase, and c-Fos, but not structured proteins. Clearance of ubiquitinated protein was largely maintained by single capped proteasome complexes (19S-20S), but accumulation occurs when all 19S capped proteasome complexes are depleted. This study illustrates the first example of a small molecule capable of targeting disordered proteins for degradation by regulating the dynamic equilibrium between different proteasome complexes.
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Affiliation(s)
- Evert Njomen
- Department of Chemistry , Michigan State University , East Lansing , Michigan 48824 , United States
| | - Pawel A Osmulski
- Institute of Biotechnology , University of Texas Health Science Center at San Antonio , 15355 Lambda Drive , San Antonio , Texas 78245 , United States
| | - Corey L Jones
- Department of Chemistry , Michigan State University , East Lansing , Michigan 48824 , United States
| | - Maria Gaczynska
- Institute of Biotechnology , University of Texas Health Science Center at San Antonio , 15355 Lambda Drive , San Antonio , Texas 78245 , United States
| | - Jetze J Tepe
- Department of Chemistry , Michigan State University , East Lansing , Michigan 48824 , United States
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6
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Jones CL, Njomen E, Sjögren B, Dexheimer TS, Tepe JJ. Small Molecule Enhancement of 20S Proteasome Activity Targets Intrinsically Disordered Proteins. ACS Chem Biol 2017; 12:2240-2247. [PMID: 28719185 DOI: 10.1021/acschembio.7b00489] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The 20S proteasome is the main protease for the degradation of oxidatively damaged and intrinsically disordered proteins. When accumulation of disordered or oxidatively damaged proteins exceeds proper clearance in neurons, imbalanced pathway signaling or aggregation occurs, which have been implicated in the pathogenesis of several neurological disorders. Screening of the NIH Clinical Collection and Prestwick libraries identified the neuroleptic agent chlorpromazine as a lead agent capable of enhancing 20S proteasome activity. Chemical manipulation of chlorpromazine abrogated its D2R receptor binding affinity while retaining its ability to enhance 20S mediated proteolysis at low micromolar concentrations. The resulting small molecule enhancers of 20S proteasome activity induced the degradation of intrinsically disordered proteins, α-synuclein, and tau but not structured proteins. These small molecule 20S agonists can serve as leads to explore the therapeutic potential of 20S activation or as new tools to provide insight into the yet unclear mechanics of 20S-gate regulation.
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Affiliation(s)
- Corey L. Jones
- Department
of Chemistry and ‡Department of Pharmacology and Toxicology, Michigan State University, East
Lansing, Michigan 48824, United States
| | - Evert Njomen
- Department
of Chemistry and ‡Department of Pharmacology and Toxicology, Michigan State University, East
Lansing, Michigan 48824, United States
| | - Benita Sjögren
- Department
of Chemistry and ‡Department of Pharmacology and Toxicology, Michigan State University, East
Lansing, Michigan 48824, United States
| | - Thomas S. Dexheimer
- Department
of Chemistry and ‡Department of Pharmacology and Toxicology, Michigan State University, East
Lansing, Michigan 48824, United States
| | - Jetze J. Tepe
- Department
of Chemistry and ‡Department of Pharmacology and Toxicology, Michigan State University, East
Lansing, Michigan 48824, United States
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7
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Santoro AM, Cunsolo A, D'Urso A, Sbardella D, Tundo GR, Ciaccio C, Coletta M, Diana D, Fattorusso R, Persico M, Di Dato A, Fattorusso C, Milardi D, Purrello R. Cationic porphyrins are tunable gatekeepers of the 20S proteasome. Chem Sci 2015; 7:1286-1297. [PMID: 29910886 PMCID: PMC5975898 DOI: 10.1039/c5sc03312h] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 11/06/2015] [Indexed: 12/17/2022] Open
Abstract
Three homologous cationic porphyrins differently affect the 20S proteasome gating mechanism.
The 20S proteasome is a barrel-shaped enzymatic assembly playing a critical role in proteome maintenance. Access of proteasome substrates to the catalytic chamber is finely regulated through gating mechanisms which involve aromatic and negatively charged residues located at the N-terminal tails of α subunits. However, despite the importance of gates in regulating proteasome function, up to now very few molecules have been shown to interfere with the equilibrium by which the catalytic channel exchanges between the open and closed states. In this light, and inspired by previous results evidencing the antiproteasome potential of cationic porphyrins, here we combine experimental (enzyme kinetics, UV stopped flow and NMR) and computational (bioinformatic analysis and docking studies) approaches to inspect proteasome inhibition by meso-tetrakis(4-N-methylpyridyl)-porphyrin (H2T4) and its two ortho- and meta-isomers. We show that in a first, fast binding event H2T4 accommodates in a pocket made of negatively charged and aromatic residues present in α1 (Asp10, Phe9), α3 (Tyr5), α5 (Asp9, Tyr8), α6 (Asp7, Tyr6) and α7 (Asp9, Tyr8) subunits thereby stabilizing the closed conformation. A second, slower binding mode involves interaction with the grooves which separate the α- from the β-rings. Of note, the proteasome inhibition by ortho- and meta-H2T4 decreases significantly if compared to the parent compound, thus underscoring the role played by spatial distribution of the four peripheral positive charges in regulating proteasome–ligand interactions. We think that our results may pave the way to further studies aimed at rationalizing the molecular basis of novel, and more sophisticated, proteasome regulatory mechanisms.
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Affiliation(s)
- Anna M Santoro
- Istituto di Biostrutture e Bioimmagini - CNR UOS di Catania , Via P. Gaifami 18 , 95126 Catania , Italy .
| | - Alessandra Cunsolo
- Dipartimento di Scienze Chimiche , Università di Catania , Viale Andrea Doria 6 , 95125 Catania , Italy .
| | - Alessandro D'Urso
- Dipartimento di Scienze Chimiche , Università di Catania , Viale Andrea Doria 6 , 95125 Catania , Italy .
| | - Diego Sbardella
- Dipartimento di Scienze Cliniche e Medicina Traslazionale , Università di Roma Tor Vergata , Via Montpellier 1 , I-00133 Roma , Italy .
| | - Grazia R Tundo
- Dipartimento di Scienze Cliniche e Medicina Traslazionale , Università di Roma Tor Vergata , Via Montpellier 1 , I-00133 Roma , Italy .
| | - Chiara Ciaccio
- Dipartimento di Scienze Cliniche e Medicina Traslazionale , Università di Roma Tor Vergata , Via Montpellier 1 , I-00133 Roma , Italy .
| | - Massimiliano Coletta
- Dipartimento di Scienze Cliniche e Medicina Traslazionale , Università di Roma Tor Vergata , Via Montpellier 1 , I-00133 Roma , Italy .
| | - Donatella Diana
- Istituto di Biostrutture e Bioimmagini , CNR , Via Mezzocannone 16 , 80134 Napoli , Italy
| | - Roberto Fattorusso
- Dipartimento di Scienze e Tecnologie Ambientali , Biologiche e Farmaceutiche , Seconda Università degli Studi Napoli , Via Vivaldi 43 , 81100 , Caserta , Italy .
| | - Marco Persico
- Dipartimento di Farmacia Università di Napoli "Federico II" , Via D. Montesano , 49 I-80131 Napoli , Italy .
| | - Antonio Di Dato
- Dipartimento di Farmacia Università di Napoli "Federico II" , Via D. Montesano , 49 I-80131 Napoli , Italy .
| | - Caterina Fattorusso
- Dipartimento di Farmacia Università di Napoli "Federico II" , Via D. Montesano , 49 I-80131 Napoli , Italy .
| | - Danilo Milardi
- Istituto di Biostrutture e Bioimmagini - CNR UOS di Catania , Via P. Gaifami 18 , 95126 Catania , Italy .
| | - Roberto Purrello
- Dipartimento di Scienze Chimiche , Università di Catania , Viale Andrea Doria 6 , 95125 Catania , Italy .
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8
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Drews O, Taegtmeyer H. Targeting the ubiquitin-proteasome system in heart disease: the basis for new therapeutic strategies. Antioxid Redox Signal 2014; 21:2322-43. [PMID: 25133688 PMCID: PMC4241867 DOI: 10.1089/ars.2013.5823] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
SIGNIFICANCE Novel therapeutic strategies to treat heart failure are greatly needed. The ubiquitin-proteasome system (UPS) affects the structure and function of cardiac cells through targeted degradation of signaling and structural proteins. This review discusses both beneficial and detrimental consequences of modulating the UPS in the heart. RECENT ADVANCES Proteasome inhibitors were first used to test the role of the UPS in cardiac disease phenotypes, indicating therapeutic potential. In early cardiac remodeling and pathological hypertrophy with increased proteasome activities, proteasome inhibition prevented or restricted disease progression and contractile dysfunction. Conversely, enhancing proteasome activities by genetic manipulation, pharmacological intervention, or ischemic preconditioning also improved the outcome of cardiomyopathies and infarcted hearts with impaired cardiac and UPS function, which is, at least in part, caused by oxidative damage. CRITICAL ISSUES An understanding of the UPS status and the underlying mechanisms for its potential deregulation in cardiac disease is critical for targeted interventions. Several studies indicate that type and stage of cardiac disease influence the dynamics of UPS regulation in a nonlinear and multifactorial manner. Proteasome inhibitors targeting all proteasome complexes are associated with cardiotoxicity in humans. Furthermore, the type and dosage of proteasome inhibitor impact the pathogenesis in nonuniform ways. FUTURE DIRECTIONS Systematic analysis and targeting of individual UPS components with established and innovative tools will unravel and discriminate regulatory mechanisms that contribute to and protect against the progression of cardiac disease. Integrating this knowledge in drug design may reduce adverse effects on the heart as observed in patients treated with proteasome inhibitors against noncardiac diseases, especially cancer.
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Affiliation(s)
- Oliver Drews
- 1 Division of Cardiovascular Physiology, Institute of Physiology and Pathophysiology , Heidelberg University, Heidelberg, Germany
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9
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Azevedo LM, Lansdell TA, Ludwig JR, Mosey RA, Woloch DK, Cogan DP, Patten GP, Kuszpit MR, Fisk JS, Tepe JJ. Inhibition of the human proteasome by imidazoline scaffolds. J Med Chem 2013; 56:5974-8. [PMID: 23789888 DOI: 10.1021/jm400235r] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The proteasome has emerged as the primary target for the treatment of multiple myeloma. Unfortunately, nearly all patients develop resistance to competitive-type proteasome inhibitors such as bortezomib. Herein, we describe the optimization of noncompetitive proteasome inhibitors to yield derivatives that exhibit nanomolar potency (compound 49, IC50 130 nM) toward proteasome inhibition and overcome bortezomib resistance. These studies illustrate the feasibility of the development of noncompetitive proteasome inhibitors as additives and/or alternatives to competitive proteasome inhibitors.
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Affiliation(s)
- Lauren M Azevedo
- Department of Chemistry, Michigan State University , East Lansing, Michigan 48824, United States
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10
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Lansdell TA, Hurchla MA, Xiang J, Hovde S, Weilbaecher KN, Henry RW, Tepe JJ. Noncompetitive modulation of the proteasome by imidazoline scaffolds overcomes bortezomib resistance and delays MM tumor growth in vivo. ACS Chem Biol 2013. [PMID: 23198928 DOI: 10.1021/cb300568r] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Multiple myeloma (MM) is a malignant disorder of differentiated B-cells for which standard care involves the inhibition of the proteasome. All clinically used proteasome inhibitors, including the chemotherapeutic drug bortezomib, target the catalytic active sites of the proteasome and inhibit protein proteolysis by competing with substrate binding. However, nearly all (~97%) patients become intolerant or resistant to treatments within a few years, after which the average survival time is less than 1 year. We describe herein the inhibition of the human proteasome via a noncompetitive mechanism by the imidazoline scaffold, TCH-13. Consistent with a mechanism distinct from that of competitive inhibitors, TCH-013 acts additively with and overcomes resistance to bortezomib. Importantly, TCH-013 induces apoptosis in a panel of myeloma and leukemia cell lines, but in contrast, normal lymphocytes, primary bone marrow stromal cells (hBMSC), and macrophages are resistant to its cytotoxic effects. TCH-013 was equally effective in blocking MM cell growth in co-cultures of MM cells with hBMSC isolated from CD138 negative bone marrow (BM) samples of MM patients. The cellular activity translated well in vivo where TCH-013 delayed tumor growth in an MM xenograft model to a similar extent as bortezomib.
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Affiliation(s)
| | - Michelle A. Hurchla
- Department of Medicine, Division
of Oncology, Washington University School of Medicine, St. Louis, Missouri, United States
| | - Jingyu Xiang
- Department of Medicine, Division
of Oncology, Washington University School of Medicine, St. Louis, Missouri, United States
| | | | - Katherine N. Weilbaecher
- Department of Medicine, Division
of Oncology, Washington University School of Medicine, St. Louis, Missouri, United States
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11
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Rodriguez KA, Edrey YH, Osmulski P, Gaczynska M, Buffenstein R. Altered composition of liver proteasome assemblies contributes to enhanced proteasome activity in the exceptionally long-lived naked mole-rat. PLoS One 2012; 7:e35890. [PMID: 22567116 PMCID: PMC3342291 DOI: 10.1371/journal.pone.0035890] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Accepted: 03/27/2012] [Indexed: 02/07/2023] Open
Abstract
The longest-lived rodent, the naked mole-rat (Bathyergidae; Heterocephalus glaber), maintains robust health for at least 75% of its 32 year lifespan, suggesting that the decline in genomic integrity or protein homeostasis routinely observed during aging, is either attenuated or delayed in this extraordinarily long-lived species. The ubiquitin proteasome system (UPS) plays an integral role in protein homeostasis by degrading oxidatively-damaged and misfolded proteins. In this study, we examined proteasome activity in naked mole-rats and mice in whole liver lysates as well as three subcellular fractions to probe the mechanisms behind the apparently enhanced effectiveness of UPS. We found that when compared with mouse samples, naked mole-rats had significantly higher chymotrypsin-like (ChT-L) activity and a two-fold increase in trypsin-like (T-L) in both whole lysates as well as cytosolic fractions. Native gel electrophoresis of the whole tissue lysates showed that the 20S proteasome was more active in the longer-lived species and that 26S proteasome was both more active and more populous. Western blot analyses revealed that both 19S subunits and immunoproteasome catalytic subunits are present in greater amounts in the naked mole-rat suggesting that the observed higher specific activity may be due to the greater proportion of immunoproteasomes in livers of healthy young adults. It thus appears that proteasomes in this species are primed for the efficient removal of stress-damaged proteins. Further characterization of the naked mole-rat proteasome and its regulation could lead to important insights on how the cells in these animals handle increased stress and protein damage to maintain a longer health in their tissues and ultimately a longer life.
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Affiliation(s)
- Karl A. Rodriguez
- Sam and Ann Barshop Institute for Aging and Longevity Studies, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
- Department of Physiology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Yael H. Edrey
- Sam and Ann Barshop Institute for Aging and Longevity Studies, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
- Department of Physiology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Pawel Osmulski
- Sam and Ann Barshop Institute for Aging and Longevity Studies, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
- Department of Molecular Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Maria Gaczynska
- Sam and Ann Barshop Institute for Aging and Longevity Studies, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
- Department of Molecular Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Rochelle Buffenstein
- Sam and Ann Barshop Institute for Aging and Longevity Studies, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
- Department of Physiology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
- Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
- * E-mail:
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12
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Needham PG, Mikoluk K, Dhakarwal P, Khadem S, Snyder AC, Subramanya AR, Brodsky JL. The thiazide-sensitive NaCl cotransporter is targeted for chaperone-dependent endoplasmic reticulum-associated degradation. J Biol Chem 2011; 286:43611-43621. [PMID: 22027832 DOI: 10.1074/jbc.m111.288928] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The thiazide-sensitive NaCl cotransporter (NCC, SLC12A3) mediates salt reabsorption in the distal nephron of the kidney and is the target of thiazide diuretics, which are commonly prescribed to treat hypertension. Mutations in NCC also give rise to Gitelman syndrome, a hereditary salt-wasting disorder thought in most cases to arise from impaired NCC biogenesis through enhanced endoplasmic reticulum-associated degradation (ERAD). Because the machinery that mediates NCC quality control is completely undefined, we employed yeast as a model heterologous expression system to identify factors involved in NCC degradation. We confirmed that NCC was a bona fide ERAD substrate in yeast, as the majority of NCC polypeptide was integrated into ER membranes, and its turnover rate was sensitive to proteasome inhibition. NCC degradation was primarily dependent on the ER membrane-associated E3 ubiquitin ligase Hrd1. Whereas several ER luminal chaperones were dispensable for NCC ERAD, NCC ubiquitination and degradation required the activity of Ssa1, a cytoplasmic Hsp70 chaperone. Compatible findings were observed when NCC was expressed in mammalian kidney cells, as the cotransporter was polyubiquitinated and degraded by the proteasome, and mammalian cytoplasmic Hsp70 (Hsp72) coexpression stimulated the degradation of newly synthesized NCC. Hsp70 also preferentially associated with the ER-localized NCC glycosylated species, indicating that cytoplasmic Hsp70 plays a critical role in selecting immature forms of NCC for ERAD. Together, these results provide the first survey of components involved in the ERAD of a mammalian SLC12 cation chloride cotransporter and provide a framework for future studies on NCC ER quality control.
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Affiliation(s)
- Patrick G Needham
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15261
| | - Kasia Mikoluk
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15261
| | - Pradeep Dhakarwal
- Department of Medicine, Renal-Electrolyte Division, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261
| | - Shaheen Khadem
- Department of Medicine, Renal-Electrolyte Division, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261; Veterans Affairs Pittsburgh Healthcare System, Pittsburgh, Pennsylvania 15261
| | - Avin C Snyder
- Department of Medicine, Renal-Electrolyte Division, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261
| | - Arohan R Subramanya
- Department of Medicine, Renal-Electrolyte Division, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261; Veterans Affairs Pittsburgh Healthcare System, Pittsburgh, Pennsylvania 15261.
| | - Jeffrey L Brodsky
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15261
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13
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Dang Z, Lin A, Ho P, Soroka D, Lee KH, Huang L, Chen CH. Synthesis and proteasome inhibition of lithocholic acid derivatives. Bioorg Med Chem Lett 2011; 21:1926-8. [PMID: 21388808 DOI: 10.1016/j.bmcl.2011.02.041] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2011] [Revised: 02/08/2011] [Accepted: 02/14/2011] [Indexed: 01/02/2023]
Abstract
A new class of proteasome inhibitors was synthesized using lithocholic acid as a scaffold. Modification at the C-3 position of lithocholic acid with a series of acid acyl groups yielded compounds with a range of potency on proteasome inhibition. Among them, the phenylene diacetic acid hemiester derivative (13) displayed the most potent proteasome inhibition with IC(50) = 1.9 μM. Enzyme kinetic analysis indicates that these lithocholic acid derivatives are noncompetitive inhibitors of the proteasome.
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Affiliation(s)
- Zhao Dang
- Department of Surgery, Duke University Medical Center, Durham, NC 27710, USA
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14
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Liggett A, Crawford L, Walker B, Morris T, Irvine A. Methods for measuring proteasome activity: Current limitations and future developments. Leuk Res 2010; 34:1403-9. [DOI: 10.1016/j.leukres.2010.07.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2010] [Revised: 06/10/2010] [Accepted: 07/03/2010] [Indexed: 10/19/2022]
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Kocabıyık S, Özdemir İ, Zwickl P, Özdoğan S. Molecular cloning and co-expression of Thermoplasma volcanium proteasome subunit genes. Protein Expr Purif 2010; 73:223-30. [DOI: 10.1016/j.pep.2010.05.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Revised: 05/05/2010] [Accepted: 05/05/2010] [Indexed: 10/19/2022]
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Rodriguez K, Gaczynska M, Osmulski PA. Molecular mechanisms of proteasome plasticity in aging. Mech Ageing Dev 2010; 131:144-55. [PMID: 20080121 PMCID: PMC2849732 DOI: 10.1016/j.mad.2010.01.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2009] [Revised: 12/24/2009] [Accepted: 01/09/2010] [Indexed: 11/15/2022]
Abstract
The ubiquitin-proteasome pathway plays a crucial role in regulation of intracellular protein turnover. Proteasome, the central protease of the pathway, encompasses multi-subunit assemblies sharing a common catalytic core supplemented by regulatory modules and localizing to different subcellular compartments. To better comprehend age-related functions of the proteasome we surveyed content, composition and catalytic properties of the enzyme in cytosolic, microsomal and nuclear fractions obtained from mouse livers subjected to organismal aging. We found that during aging subunit composition and subcellular distribution of proteasomes changed without substantial alterations in the total level of core complexes. We observed that the general decline in proteasomes functions was limited to nuclear and cytosolic compartments. Surprisingly, the observed changes in activity and specificity were linked to the amount of the activator module and distinct composition of the catalytic subunits. In contrast, activity, specificity and composition of the microsomal-associated proteasomes remained mostly unaffected by aging; however their relative contribution to the total activity was substantially elevated. Unexpectedly, the nuclear proteasomes were affected most profoundly by aging possibly triggering significant changes in cellular signaling and transcription. Collectively, the data indicate an age-related refocusing of proteasome from the compartment-specific functions towards general protein maintenance.
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Affiliation(s)
- Karl Rodriguez
- Department of Molecular Medicine, Institute of Biotechnology, University of Texas Health Science Center, San Antonio, 15355 Lambda Drive, San Antonio, TX 78245
| | - Maria Gaczynska
- Department of Molecular Medicine, Institute of Biotechnology, University of Texas Health Science Center, San Antonio, 15355 Lambda Drive, San Antonio, TX 78245
| | - Pawel A. Osmulski
- Department of Molecular Medicine, Institute of Biotechnology, University of Texas Health Science Center, San Antonio, 15355 Lambda Drive, San Antonio, TX 78245
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Young GW, Wang Y, Ping P. Understanding proteasome assembly and regulation: importance to cardiovascular medicine. Trends Cardiovasc Med 2008; 18:93-8. [PMID: 18436147 DOI: 10.1016/j.tcm.2008.01.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2007] [Revised: 01/18/2008] [Accepted: 01/24/2008] [Indexed: 01/30/2023]
Abstract
The cardiac proteasome is increasingly recognized as a complex, heterogeneous, and dynamic organelle contributing to the modulation of cardiac function in health and diseases. The emerging picture of the proteasome system reveals a highly regulated and organized molecular machine integrated into multiple biologic processes of the cell. Full appreciation of its cardiovascular relevance requires an understanding of its proteolytic function as well as its underlying regulatory mechanisms, of which assembly, stoichiometry, posttranslational modification, and the role of the associating partners are increasingly poignant.
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Affiliation(s)
- Glen W Young
- Department of Physiology, Medicine/Division of Cardiology, David Geffen School of Medicine at UCLA, University of California-Los Angeles, CA 90095, USA
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Silva GM, Netto LES, Discola KF, Piassa-Filho GM, Pimenta DC, Bárcena JA, Demasi M. Role of glutaredoxin 2 and cytosolic thioredoxins in cysteinyl-based redox modification of the 20S proteasome. FEBS J 2008; 275:2942-55. [PMID: 18435761 DOI: 10.1111/j.1742-4658.2008.06441.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The yeast 20S proteasome is subject to sulfhydryl redox alterations, such as the oxidation of cysteine residues (Cys-SH) into cysteine sulfenic acid (Cys-SOH), followed by S-glutathionylation (Cys-S-SG). Proteasome S-glutathionylation promotes partial loss of chymotrypsin-like activity and post-acidic cleavage without alteration of the trypsin-like proteasomal activity. Here we show that the 20S proteasome purified from stationary-phase cells was natively S-glutathionylated. Moreover, recombinant glutaredoxin 2 removes glutathione from natively or in vitro S-glutathionylated 20S proteasome, allowing the recovery of chymotrypsin-like activity and post-acidic cleavage. Glutaredoxin 2 deglutathionylase activity was dependent on its entry into the core particle, as demonstrated by stimulating S-glutathionylated proteasome opening. Under these conditions, deglutathionylation of the 20S proteasome and glutaredoxin 2 degradation were increased when compared to non-stimulated samples. Glutaredoxin 2 fragmentation by the 20S proteasome was evaluated by SDS-PAGE and mass spectrometry, and S-glutathionylation was evaluated by either western blot analyses with anti-glutathione IgG or by spectrophotometry with the thiol reactant 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole. It was also observed in vivo that glutaredoxin 2 was ubiquitinated in cellular extracts of yeast cells grown in glucose-containing medium. Other cytoplasmic oxido-reductases, namely thioredoxins 1 and 2, were also active in 20S proteasome deglutathionylation by a similar mechanism. These results indicate for the first time that 20S proteasome cysteinyl redox modification is a regulated mechanism coupled to enzymatic deglutathionylase activity.
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Affiliation(s)
- Gustavo M Silva
- Instituto Butantan, Laboratório de Bioquímica e Biofísica, São Paulo, Brazil, and Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, Brazil
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Abstract
The proteasome should be an ideal molecule for studies on large enzymatic complexes, given its multisubunit and modular structure, compartmentalized design, numerous activities, and its own means of regulation. Considering the recent increased interest in the ubiquitin-proteasome pathway, it is surprising that biophysical approaches to study this enzymatic assembly are applied with limited frequency. Methods including atomic force microscopy, fluorescence spectroscopy, surface plasmon resonance, and high-pressure procedures all have gained popularity in characterization of the proteasome. These methods provide significant and often unexpected insight regarding the structure and function of the enzyme. This chapter describes the use of atomic force microscopy for dynamic structural studies of the proteasome.
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Affiliation(s)
- Pawel A Osmulski
- Department of Molecular Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX 78245-3207, USA
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