1
|
Burov A, Grigorieva E, Lebedev T, Vedernikova V, Popenko V, Astakhova T, Leonova O, Spirin P, Prassolov V, Karpov V, Morozov A. Multikinase inhibitors modulate non-constitutive proteasome expression in colorectal cancer cells. Front Mol Biosci 2024; 11:1351641. [PMID: 38774235 PMCID: PMC11106389 DOI: 10.3389/fmolb.2024.1351641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Accepted: 01/31/2024] [Indexed: 05/24/2024] Open
Abstract
Introduction: Proteasomes are multi-subunit protein complexes responsible for protein degradation in cells. Immunoproteasomes and intermediate proteasomes (together non-constitutive proteasomes) are specific forms of proteasomes frequently associated with immune response, antigen presentation, inflammation and stress. Expression of non-constitutive proteasome subunits has a prognostic value in several types of cancer. Thus, factors that modulate non-constitutive proteasome expression in tumors are of particular interest. Multikinase inhibitors (MKIs) demonstrate promising results in treatment of cancer. At the same time, their immunomodulatory properties and effects on non-constitutive proteasome expression in colorectal cancer cells are poorly investigated. Methods: Proteasome subunit expression in colorectal cancer was evaluated by bioinformatic analysis of available datasets. Two colorectal cancer cell lines, expressing fluorescent non-constitutive proteasomes were treated with multikinase inhibitors: regorafenib and sorafenib. The proteasome subunit expression was assessed by real-time PCR, Western blotting and flow cytometry. The proteasome activity was studied using proteasome activity-based probe and fluorescent substrates. Intracellular proteasome localization was revealed by confocal microscopy. Reactive oxygen species levels following treatment were determined in cells. Combined effect of proteasome inhibition and treatment with MKIs on viability of cells was estimated. Results: Expression of non-constitutive proteasomes is increased in BRAF-mutant colorectal tumors. Regorafenib and sorafenib stimulated the activity and synthesis of non-constitutive proteasomes in examined cell lines. MKIs induced oxidative stress and redistribution of proteasomes within cells. Sorafenib stimulated formation of cytoplasmic aggregates, containing proteolyticaly active non-constitutive proteasomes, while regorafenib had no such effect. MKIs caused no synergistic action when were combined with the proteasome inhibitor. Discussion: Obtained results indicate that MKIs might affect the crosstalk between cancer cells and immune cells via modulation of intracellular proteasome pool. Observed phenomenon should be considered when MKI-based therapy is applied.
Collapse
Affiliation(s)
- Alexander Burov
- Laboratory of Regulation of Intracellular Proteolysis, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Ekaterina Grigorieva
- Laboratory of Regulation of Intracellular Proteolysis, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
- Moscow Institute of Physics and Technology, National Research University, Dolgoprudny, Russia
| | - Timofey Lebedev
- Department of Cancer Cell Biology, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Valeria Vedernikova
- Moscow Institute of Physics and Technology, National Research University, Dolgoprudny, Russia
- Department of Cancer Cell Biology, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Vladimir Popenko
- Department of Cancer Cell Biology, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Tatiana Astakhova
- Laboratory of Biochemistry of Ontogenesis Processes, Koltzov Institute of Developmental Biology, Russian Academy of Sciences, Moscow, Russia
| | - Olga Leonova
- Department of Cancer Cell Biology, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Pavel Spirin
- Department of Cancer Cell Biology, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Vladimir Prassolov
- Department of Cancer Cell Biology, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Vadim Karpov
- Laboratory of Regulation of Intracellular Proteolysis, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Alexey Morozov
- Laboratory of Regulation of Intracellular Proteolysis, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| |
Collapse
|
2
|
van Oostrum M, Blok TM, Giandomenico SL, Tom Dieck S, Tushev G, Fürst N, Langer JD, Schuman EM. The proteomic landscape of synaptic diversity across brain regions and cell types. Cell 2023; 186:5411-5427.e23. [PMID: 37918396 PMCID: PMC10686415 DOI: 10.1016/j.cell.2023.09.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 08/18/2023] [Accepted: 09/28/2023] [Indexed: 11/04/2023]
Abstract
Neurons build synaptic contacts using different protein combinations that define the specificity, function, and plasticity potential of synapses; however, the diversity of synaptic proteomes remains largely unexplored. We prepared synaptosomes from 7 different transgenic mouse lines with fluorescently labeled presynaptic terminals. Combining microdissection of 5 different brain regions with fluorescent-activated synaptosome sorting (FASS), we isolated and analyzed the proteomes of 18 different synapse types. We discovered ∼1,800 unique synapse-type-enriched proteins and allocated thousands of proteins to different types of synapses (https://syndive.org/). We identify shared synaptic protein modules and highlight the proteomic hotspots for synapse specialization. We reveal unique and common features of the striatal dopaminergic proteome and discover the proteome signatures that relate to the functional properties of different interneuron classes. This study provides a molecular systems-biology analysis of synapses and a framework to integrate proteomic information for synapse subtypes of interest with cellular or circuit-level experiments.
Collapse
Affiliation(s)
- Marc van Oostrum
- Max Planck Institute for Brain Research, Frankfurt am Main, Germany
| | - Thomas M Blok
- Max Planck Institute for Brain Research, Frankfurt am Main, Germany
| | | | | | - Georgi Tushev
- Max Planck Institute for Brain Research, Frankfurt am Main, Germany
| | - Nicole Fürst
- Max Planck Institute for Brain Research, Frankfurt am Main, Germany
| | - Julian D Langer
- Max Planck Institute for Brain Research, Frankfurt am Main, Germany; Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Erin M Schuman
- Max Planck Institute for Brain Research, Frankfurt am Main, Germany.
| |
Collapse
|
3
|
Zakluta AS, Shilova VY, Zatsepina OG. The Effect of the Knockout of Major Transsulfuration Genes on the Pattern of Protein Synthesis in D. melanogaster. Mol Biol 2023. [DOI: 10.1134/s0026893323010144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
|
4
|
The ATP/Mg2+ Balance Affects the Degradation of Short Fluorogenic Substrates by the 20S Proteasome. Methods Protoc 2022; 5:mps5010015. [PMID: 35200531 PMCID: PMC8875927 DOI: 10.3390/mps5010015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 01/27/2022] [Accepted: 02/02/2022] [Indexed: 11/21/2022] Open
Abstract
Proteasomes hydrolyze most cellular proteins. The standard reaction to determine proteasome activity in cellular lysate or elsewhere contains AMC-conjugated peptide substrate, ATP, Mg2+, and DTT. ATP and Mg2+ are included to maintain 26S proteasome functionality. However, most cellular proteasomes are 20S proteasomes, and the effects of ATP on the turnover of fluorogenic substrates by 20S complexes are largely unknown. Here, we evaluated the effect of ATP alone or in combination with Mg2+ on the degradation of AMC-conjugated fluorogenic substrates by purified 20S proteasomes. Degradation of substrates used to determine chymotrypsin-, caspase- and trypsin-like proteasome activities was gradually decreased with the rise of ATP concentration from 0.25 to 10 mM. These effects were not associated with the blockage of the proteasome catalytic subunit active sites or unspecific alterations of AMC fluorescence by the ATP. However, ATP-induced peptide degradation slowdown was rescued by the addition of Mg2+. Moreover, the substrate degradation efficacy was proportional to the Mg2+/ATP ratio, being equal to control values when equimolar concentrations of the molecules were used. The obtained results indicate that when proteasome activity is assessed, the reciprocal effects of ATP and Mg2+ on the hydrolysis of AMC-conjugated fluorogenic substrates by the 20S proteasomes should be considered.
Collapse
|
5
|
A Cell-Based Platform for the Investigation of Immunoproteasome Subunit β5i Expression and Biology of β5i-Containing Proteasomes. Cells 2021; 10:cells10113049. [PMID: 34831272 PMCID: PMC8616536 DOI: 10.3390/cells10113049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Revised: 10/24/2021] [Accepted: 11/02/2021] [Indexed: 11/17/2022] Open
Abstract
The degradation of most intracellular proteins is a dynamic and tightly regulated process performed by proteasomes. To date, different forms of proteasomes have been identified. Currently the role of non-constitutive proteasomes (immunoproteasomes (iPs) and intermediate proteasomes (intPs)) has attracted special attention. Here, using a CRISPR-Cas9 nickase technology, four cell lines: histiocytic lymphoma, colorectal adenocarcinoma, cervix adenocarcinoma, and hepatocarcinoma were modified to express proteasomes with mCherry-tagged β5i subunit, which is a catalytic subunit of iPs and intPs. Importantly, the expression of the chimeric gene in modified cells is under the control of endogenous regulatory mechanisms and is increased following IFN-γ and/or TNF-α stimulation. Fluorescent proteasomes retain catalytic activity and are distributed within the nucleus and cytoplasm. RNAseq reveals marginal differences in gene expression profiles between the modified and wild-type cell lines. Predominant metabolic pathways and patterns of expressed receptors were identified for each cell line. Using established cell lines, we demonstrated that anti-cancer drugs Ruxolitinib, Vincristine and Gefitinib stimulated the expression of β5i-containing proteasomes, which might affect disease prognosis. Taken together, obtained cell lines can be used as a platform for real-time studies of immunoproteasome gene expression, localization of iPs and intPs, interaction of non-constitutive proteasomes with other proteins, proteasome trafficking and many other aspects of proteasome biology in living cells. Moreover, the established platform might be especially useful for fast and large-scale experiments intended to evaluate the effects of different conditions including treatment with various drugs and compounds on the proteasome pool.
Collapse
|
6
|
Liu EA, Mori E, Hamasaki F, Lieberman AP. TDP-43 proteinopathy occurs independently of autophagic substrate accumulation and underlies nuclear defects in Niemann-Pick C disease. Neuropathol Appl Neurobiol 2021; 47:1019-1032. [PMID: 34048071 DOI: 10.1111/nan.12738] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 04/21/2021] [Accepted: 05/23/2021] [Indexed: 12/12/2022]
Abstract
AIMS Neuronal cytoplasmic inclusions of TAR-DNA binding protein of 43 kDa (TDP-43) are a pathological hallmark of diverse neurodegenerative disorders, yet the processes that mediate their formation and their functional significance remain incompletely understood. Both dysfunction in autophagy and neuroinflammation have been linked to TDP-43 mislocalisation. Here, we investigate TDP-43 proteinopathy in Niemann-Pick type C disease (NPC), an autosomal recessive lysosomal storage disease (LSD) distinguished by the accumulation of unesterified cholesterol within late endosomes and lysosomes. NPC is characterised by neurodegeneration, neuroinflammation and multifocal disruption of the autophagy pathway. METHODS We utilised immunohistochemistry, confocal microscopy, electron microscopy and biochemical and gene expression studies to characterise TDP-43 pathology and autophagic substrate accumulation in Npc1-deficient mice. RESULTS In the NPC brain, cytoplasmic TDP-43 mislocalisation was independent of autophagic substrate accumulation. These pathologies occurred in distinct neuronal subtypes, as brainstem cholinergic neurons were more susceptible to TDP-43 mislocalisation, whereas glutamatergic neurons exhibited hallmarks of autophagic dysfunction. Furthermore, TDP-43 mislocalisation did not co-localise with markers of stress granules or progress to ubiquitinated aggregates over months in vivo, indicating a stable, early stage in the aggregation process. Neither microgliosis nor neuroinflammation were sufficient to drive TDP-43 proteinopathy in the NPC brain. Notably, cytoplasmic TDP-43 co-localised with the nuclear import factor importin α, and TDP-43 mislocalised neurons demonstrated nuclear membrane abnormalities and disruption of nucleocytoplasmic transport. CONCLUSION Our findings highlight the relationship between LSDs and TDP-43 proteinopathy, define its functional importance in NPC by triggering nuclear dysfunction, and expand the spectrum of TDP-43 pathology in the diseased brain.
Collapse
Affiliation(s)
- Elaine A Liu
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA.,Cellular and Molecular Biology Graduate Program, University of Michigan Medical School, Ann Arbor, MI, USA.,Medical Scientist Training Program, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Erika Mori
- Yamaguchi University School of Medicine, Ube, Japan
| | | | - Andrew P Lieberman
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA
| |
Collapse
|
7
|
Immunoproteasome Activity and Content Determine Hematopoietic Cell Sensitivity to ONX-0914 and to the Infection of Cells with Lentiviruses. Cells 2021; 10:cells10051185. [PMID: 34066177 PMCID: PMC8150886 DOI: 10.3390/cells10051185] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 05/03/2021] [Accepted: 05/07/2021] [Indexed: 01/08/2023] Open
Abstract
Proteasomes are intracellular structures responsible for protein degradation. The 20S proteasome is a core catalytic element of the proteasome assembly. Variations of catalytic subunits generate different forms of 20S proteasomes including immunoproteasomes (iPs), which are present mostly in the immune cells. Certain cells of the immune system are primary targets of retroviruses. It has been shown that several viral proteins directly affect proteasome functionality, while inhibition of proteasome activity with broad specificity proteasome inhibitors stimulates viral transduction. Here we specifically addressed the role of the immunoproteasomes during early stages of viral transduction and investigated the effects of specific immunoproteasome inhibition and activation prior to infection using a panel of cell lines. Inhibition of iPs in hematopoietic cells with immunoproteasome-specific inhibitor ONX-0914 resulted in increased infection by VSV-G pseudotyped lentiviruses. Moreover, a tendency for increased infection of cloned cells with endogenously decreased proteasome activity was revealed. Conversely, activation of iPs by IFN-γ markedly reduced the viral infectivity, which was rescued upon simultaneous immunoproteasome inhibition. Our results indicate that immunoproteasome activity might be determinative for the cellular antiretroviral resistance at least for the cells with high iP content. Finally, therapeutic application of immunoproteasome inhibitors might promote retroviral infection of cells in vivo.
Collapse
|
8
|
Du SH, Xiang YJ, Liu L, Nie M, Hou Y, Wang L, Li BB, Xu M, Teng QL, Peng J, Hou M, Shi Y. Co-Inhibition of the Immunoproteasome Subunits LMP2 and LMP7 Ameliorates Immune Thrombocytopenia. Front Immunol 2021; 11:603278. [PMID: 33552061 PMCID: PMC7855704 DOI: 10.3389/fimmu.2020.603278] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Accepted: 12/07/2020] [Indexed: 12/26/2022] Open
Abstract
The immunoproteasome, a special isoform of the 20S proteasome, is expressed when the cells receive an inflammatory signal. Immunoproteasome inhibition proved efficacy in the treatment of autoimmune diseases. However, the role of the immunoproteasome in the pathogenesis of immune thrombocytopenia (ITP) remains unknown. We found that the expression of the immunoproteasome catalytic subunit, large multifunctional protease 2 (LMP2), was significantly upregulated in peripheral blood mononuclear cells of active ITP patients compared to those of healthy controls. No significant differences in LMP7 expression were observed between patients and controls. ML604440, an specific LMP2 inhibitor, had no significant impact on the platelet count of ITP mice, while ONX-0914 (an inhibitor of both LMP2 and LMP7) increased the number of platelets. In vitro assays revealed that ONX-0914 decreased the expression of FcγRI in ITP mice and decreased that of FcγRIII in ITP patients, inhibited the activation of CD4+ T cells, and affected the differentiation of Th1 cells in patients with ITP. These results suggest that the inhibition of immunoproteasome is a potential therapeutic approach for ITP patients.
Collapse
Affiliation(s)
- Sheng-hong Du
- Department of Hematology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
- Department of Hematology, Taian Central Hospital, Taian, China
| | - Yu-jiao Xiang
- Department of Hematology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Lu Liu
- Department of Hematology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Mu Nie
- Department of Hematology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
- Division of Immunology and Allergy, Department of Medicine Solna, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - Yu Hou
- Department of Hematology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Ling Wang
- Department of Hematology, Taian Central Hospital, Taian, China
| | - Ban-ban Li
- Department of Hematology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
- Department of Hematology, Taian Central Hospital, Taian, China
| | - Miao Xu
- Department of Hematology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Qing-liang Teng
- Department of Hematology, Taian Central Hospital, Taian, China
| | - Jun Peng
- Department of Hematology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
- Shandong Provincial Key Laboratory of Immunohematology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Ming Hou
- Department of Hematology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
- Shandong Provincial Key Laboratory of Immunohematology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
- Shandong Provincial Clinical Research Center in Hematological Diseases, Jinan, China
- Leading Research Group of Scientific Innovation, Department of Science and Technology of Shandong Province, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Yan Shi
- Department of Hematology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| |
Collapse
|
9
|
Borsari C, Trader DJ, Tait A, Costi MP. Designing Chimeric Molecules for Drug Discovery by Leveraging Chemical Biology. J Med Chem 2020; 63:1908-1928. [PMID: 32023055 PMCID: PMC7997565 DOI: 10.1021/acs.jmedchem.9b01456] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
After the first seed concept introduced in the 18th century, different disciplines have attributed different names to dual-functional molecules depending on their application, including bioconjugates, bifunctional compounds, multitargeting molecules, chimeras, hybrids, engineered compounds. However, these engineered constructs share a general structure: a first component that targets a specific cell and a second component that exerts the pharmacological activity. A stable or cleavable linker connects the two modules of a chimera. Herein, we discuss the recent advances in the rapidly expanding field of chimeric molecules leveraging chemical biology concepts. This Perspective is focused on bifunctional compounds in which one component is a lead compound or a drug. In detail, we discuss chemical features of chimeric molecules and their use for targeted delivery and for target engagement studies.
Collapse
Affiliation(s)
- Chiara Borsari
- Department of Biomedicine, University of Basel, Mattenstrasse 28, 4058 Basel, Switzerland
| | - Darci J Trader
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, 610 Purdue Mall, West Lafayette, Indiana 47907, United States
| | - Annalisa Tait
- Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 103, 41125 Modena, Italy
| | - Maria P Costi
- Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 103, 41125 Modena, Italy
| |
Collapse
|
10
|
van der Kant R, Langness VF, Herrera CM, Williams DA, Fong LK, Leestemaker Y, Steenvoorden E, Rynearson KD, Brouwers JF, Helms JB, Ovaa H, Giera M, Wagner SL, Bang AG, Goldstein LSB. Cholesterol Metabolism Is a Druggable Axis that Independently Regulates Tau and Amyloid-β in iPSC-Derived Alzheimer's Disease Neurons. Cell Stem Cell 2019; 24:363-375.e9. [PMID: 30686764 PMCID: PMC6414424 DOI: 10.1016/j.stem.2018.12.013] [Citation(s) in RCA: 186] [Impact Index Per Article: 37.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 09/26/2018] [Accepted: 12/17/2018] [Indexed: 02/07/2023]
Abstract
Genetic, epidemiologic, and biochemical evidence suggests that predisposition to Alzheimer's disease (AD) may arise from altered cholesterol metabolism, although the molecular pathways that may link cholesterol to AD phenotypes are only partially understood. Here, we perform a phenotypic screen for pTau accumulation in AD-patient iPSC-derived neurons and identify cholesteryl esters (CE), the storage product of excess cholesterol, as upstream regulators of Tau early during AD development. Using isogenic induced pluripotent stem cell (iPSC) lines carrying mutations in the cholesterol-binding domain of APP or APP null alleles, we found that while CE also regulate Aβ secretion, the effects of CE on Tau and Aβ are mediated by independent pathways. Efficacy and toxicity screening in iPSC-derived astrocytes and neurons showed that allosteric activation of CYP46A1 lowers CE specifically in neurons and is well tolerated by astrocytes. These data reveal that CE independently regulate Tau and Aβ and identify a druggable CYP46A1-CE-Tau axis in AD.
Collapse
Affiliation(s)
- Rik van der Kant
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam de Boelelaan 1087, 1081 HV Amsterdam, the Netherlands
| | - Vanessa F Langness
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Cheryl M Herrera
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Daniel A Williams
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Lauren K Fong
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Yves Leestemaker
- Oncode Institute and Department of Cell and Chemical Biology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, the Netherlands
| | - Evelyne Steenvoorden
- Center for Proteomics and Metabolomics, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, the Netherlands
| | - Kevin D Rynearson
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Jos F Brouwers
- Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine, Utrecht University Yalelaan 2, 3584 CM Utrecht, the Netherlands
| | - J Bernd Helms
- Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine, Utrecht University Yalelaan 2, 3584 CM Utrecht, the Netherlands
| | - Huib Ovaa
- Oncode Institute and Department of Cell and Chemical Biology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, the Netherlands
| | - Martin Giera
- Center for Proteomics and Metabolomics, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, the Netherlands
| | - Steven L Wagner
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA; Research Biologist, VA San Diego Healthcare System, La Jolla, CA 92161, USA
| | - Anne G Bang
- Conrad Prebys Center for Chemical Genomics, Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Lawrence S B Goldstein
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA.
| |
Collapse
|
11
|
Nath SR, Yu Z, Gipson TA, Marsh GB, Yoshidome E, Robins DM, Todi SV, Housman DE, Lieberman AP. Androgen receptor polyglutamine expansion drives age-dependent quality control defects and muscle dysfunction. J Clin Invest 2018; 128:3630-3641. [PMID: 29809168 DOI: 10.1172/jci99042] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 05/24/2018] [Indexed: 12/28/2022] Open
Abstract
Skeletal muscle has emerged as a critical, disease-relevant target tissue in spinal and bulbar muscular atrophy, a degenerative disorder of the neuromuscular system caused by a CAG/polyglutamine (polyQ) expansion in the androgen receptor (AR) gene. Here, we used RNA-sequencing (RNA-Seq) to identify pathways that are disrupted in diseased muscle using AR113Q knockin mice. This analysis unexpectedly identified substantially diminished expression of numerous ubiquitin/proteasome pathway genes in AR113Q muscle, encoding approximately 30% of proteasome subunits and 20% of E2 ubiquitin conjugases. These changes were age, hormone, and glutamine length dependent and arose due to a toxic gain of function conferred by the mutation. Moreover, altered gene expression was associated with decreased levels of the proteasome transcription factor NRF1 and its activator DDI2 and resulted in diminished proteasome activity. Ubiquitinated ADRM1 was detected in AR113Q muscle, indicating the occurrence of stalled proteasomes in mutant mice. Finally, diminished expression of Drosophila orthologues of NRF1 or ADRM1 promoted the accumulation of polyQ AR protein and increased toxicity. Collectively, these data indicate that AR113Q muscle develops progressive proteasome dysfunction that leads to the impairment of quality control and the accumulation of polyQ AR protein, key features that contribute to the age-dependent onset and progression of this disorder.
Collapse
Affiliation(s)
- Samir R Nath
- Department of Pathology.,Medical Scientist Training Program, and.,Cellular and Molecular Biology Graduate Program, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | | | - Theresa A Gipson
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Gregory B Marsh
- Department of Pharmacology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | | | - Diane M Robins
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Sokol V Todi
- Department of Pharmacology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - David E Housman
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | | |
Collapse
|
12
|
Calcitonin Gene-Related Peptide Induces HIV-1 Proteasomal Degradation in Mucosal Langerhans Cells. J Virol 2017; 91:JVI.01205-17. [PMID: 28904199 DOI: 10.1128/jvi.01205-17] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 09/07/2017] [Indexed: 11/20/2022] Open
Abstract
The neuroimmune dialogue between peripheral neurons and Langerhans cells (LCs) within mucosal epithelia protects against incoming pathogens. LCs rapidly internalize human immunodeficiency virus type 1 (HIV-1) upon its sexual transmission and then trans-infect CD4+ T cells. We recently found that the neuropeptide calcitonin gene-related peptide (CGRP), secreted mucosally from peripheral neurons, inhibits LC-mediated HIV-1 trans-infection. In this study, we investigated the mechanism of CGRP-induced inhibition, focusing on HIV-1 degradation in LCs and its interplay with trans-infection. We first show that HIV-1 degradation occurs in endolysosomes in untreated LCs, and functionally blocking such degradation with lysosomotropic agents results in increased trans-infection. We demonstrate that CGRP acts via its cognate receptor and at a viral postentry step to induce faster HIV-1 degradation, but without affecting the kinetics of endolysosomal degradation. We reveal that unexpectedly, CGRP shifts HIV-1 degradation from endolysosomes toward the proteasome, providing the first evidence for functional HIV-1 proteasomal degradation in LCs. Such efficient proteasomal degradation significantly inhibits the first phase of trans-infection, and proteasomal, but not endolysosomal, inhibitors abrogate CGRP-induced inhibition. Together, our results establish that CGRP controls the HIV-1 degradation mode in LCs. The presence of endogenous CGRP within innervated mucosal tissues, especially during the sexual response, to which CGRP contributes, suggests that HIV-1 proteasomal degradation predominates in vivo Hence, proteasomal, rather than endolysosomal, HIV-1 degradation in LCs should be enhanced clinically to effectively restrict HIV-1 trans-infection.IMPORTANCE During sexual transmission, HIV-1 is internalized and degraded in LCs, the resident antigen-presenting cells in mucosal epithelia. Yet during trans-infection, infectious virions escaping degradation are transferred to CD4+ T cells, the principal HIV-1 targets. We previously found that the neuroimmune dialogue between LCs and peripheral neurons, innervating mucosal epithelia, significantly inhibits trans-infection via the action of the secreted neuropeptide CGRP on LCs. In this study, we investigated whether CGRP-induced inhibition of trans-infection is linked to CGRP-controlled HIV-1 degradation in LCs. We show that in untreated LCs, HIV-1 is functionally degraded in endolysosomes. In sharp contrast, we reveal that in CGRP-treated LCs, HIV-1 is diverted toward and degraded via another cytosolic protein degradative pathway, namely, the proteasome. These results establish that CGRP regulates HIV-1 degradation in LCs. As CGRP contributes to the sexual response and present within mucosal epithelia, HIV-1 proteasomal degradation in LCs might predominate in vivo and should be enhanced clinically.
Collapse
|
13
|
Leestemaker Y, de Jong A, Witting KF, Penning R, Schuurman K, Rodenko B, Zaal EA, van de Kooij B, Laufer S, Heck AJR, Borst J, Scheper W, Berkers CR, Ovaa H. Proteasome Activation by Small Molecules. Cell Chem Biol 2017; 24:725-736.e7. [PMID: 28552582 DOI: 10.1016/j.chembiol.2017.05.010] [Citation(s) in RCA: 101] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Revised: 03/31/2017] [Accepted: 05/03/2017] [Indexed: 12/12/2022]
Abstract
Drugs that increase 26S proteasome activity have potential therapeutic applications in the treatment of neurodegenerative diseases. A chemical genetics screen of over 2,750 compounds using a proteasome activity probe as a readout in a high-throughput live-cell fluorescence-activated cell sorting-based assay revealed more than ten compounds that increase proteasome activity, with the p38 MAPK inhibitor PD169316 being one of the most potent ones. Genetic and chemical inhibition of either p38 MAPK, its upstream regulators, ASK1 and MKK6, and downstream target, MK2, enhance proteasome activity. Chemical activation of the 26S proteasome increases PROTAC-mediated and ubiquitin-dependent protein degradation and decreases the levels of both overexpressed and endogenous α-synuclein, without affecting the overall protein turnover. In addition, survival of cells overexpressing toxic α-synuclein assemblies is increased in the presence of p38 MAPK inhibitors. These findings highlight the potential of activation of 26S proteasome activity and that this can be achieved through multiple mechanisms by distinct molecules.
Collapse
Affiliation(s)
- Yves Leestemaker
- Division of Cell Biology II, The Netherlands Cancer Institute, 1066 CX Amsterdam, the Netherlands; Department of Chemical Immunology, Leiden University Medical Center, 2300 RC Leiden, the Netherlands
| | - Annemieke de Jong
- Division of Cell Biology II, The Netherlands Cancer Institute, 1066 CX Amsterdam, the Netherlands
| | - Katharina F Witting
- Division of Cell Biology II, The Netherlands Cancer Institute, 1066 CX Amsterdam, the Netherlands; Department of Chemical Immunology, Leiden University Medical Center, 2300 RC Leiden, the Netherlands
| | - Renske Penning
- Biomolecular Mass Spectrometry and Proteomics, Utrecht University, 3584 CH Utrecht, the Netherlands
| | - Karianne Schuurman
- Division of Cell Biology II, The Netherlands Cancer Institute, 1066 CX Amsterdam, the Netherlands
| | - Boris Rodenko
- Division of Cell Biology II, The Netherlands Cancer Institute, 1066 CX Amsterdam, the Netherlands
| | - Esther A Zaal
- Biomolecular Mass Spectrometry and Proteomics, Utrecht University, 3584 CH Utrecht, the Netherlands
| | - Bert van de Kooij
- Division of Immunology, The Netherlands Cancer Institute, 2300 RC Amsterdam, the Netherlands
| | - Stefan Laufer
- Institute of Pharmacy, University of Tübingen, 72076 Tübingen, Germany
| | - Albert J R Heck
- Biomolecular Mass Spectrometry and Proteomics, Utrecht University, 3584 CH Utrecht, the Netherlands
| | - Jannie Borst
- Division of Immunology, The Netherlands Cancer Institute, 2300 RC Amsterdam, the Netherlands
| | - Wiep Scheper
- Department of Clinical Genetics and Alzheimer Center, VU University Medical Center, 1081 HV Amsterdam, the Netherlands; Department of Functional Genome Analysis, VU University, 1081 HV Amsterdam, the Netherlands
| | - Celia R Berkers
- Biomolecular Mass Spectrometry and Proteomics, Utrecht University, 3584 CH Utrecht, the Netherlands.
| | - Huib Ovaa
- Division of Cell Biology II, The Netherlands Cancer Institute, 1066 CX Amsterdam, the Netherlands; Department of Chemical Immunology, Leiden University Medical Center, 2300 RC Leiden, the Netherlands.
| |
Collapse
|
14
|
Berkers CR, de Jong A, Schuurman KG, Linnemann C, Geenevasen JAJ, Schumacher TNM, Rodenko B, Ovaa H. Peptide Splicing in the Proteasome Creates a Novel Type of Antigen with an Isopeptide Linkage. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2015; 195:4075-84. [PMID: 26401000 PMCID: PMC4642838 DOI: 10.4049/jimmunol.1402454] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Accepted: 06/23/2015] [Indexed: 11/19/2022]
Abstract
The proteasome is able to create spliced Ags, in which two distant parts of a protein are excised and ligated together to form a novel peptide, for presentation by MHC class I molecules. These noncontiguous epitopes are generated via a transpeptidation reaction catalyzed by the proteasomal active sites. Transpeptidation reactions in the proteasome follow explicit rules and occur particularly efficiently when the C-terminal ligation partner contains a lysine or arginine residue at the site of ligation. Lysine contains two amino groups that theoretically may both participate in ligation reactions, implying that potentially not only peptide but also isopeptide linkages could be formed. Using nuclear magnetic resonance spectroscopy, we demonstrate in the present study that the proteasome can use the ε-amino group of an N-terminal lysine residue in transpeptidation reactions to create a novel type of posttranslationally modified epitopes. We show that the overall efficiency of ε ligation is only 10-fold lower as compared with α ligation, suggesting that the proteasome can produce sufficient isopeptide Ag to evoke a T cell response. Additionally, we show that isopeptides are more stable toward further proteasomal processing than are normal peptides, and we demonstrate that isopeptides can bind to HLA-A2.1 and HLA-A3 with high affinity. These properties likely increase the fraction of ε-ligated peptides presented on the cell surface for CD8(+) T cell surveillance. Finally, we show that isopeptide Ags are immunogenic in vivo. We postulate that ε ligation is a genuine posttranslational modification, suggesting that the proteasome can create a novel type of Ag that is likely to play a role in immunity.
Collapse
Affiliation(s)
- Celia R Berkers
- Division of Cell Biology, Netherlands Cancer Institute, 1066 CX Amsterdam, the Netherlands
| | - Annemieke de Jong
- Division of Cell Biology, Netherlands Cancer Institute, 1066 CX Amsterdam, the Netherlands
| | - Karianne G Schuurman
- Division of Cell Biology, Netherlands Cancer Institute, 1066 CX Amsterdam, the Netherlands
| | - Carsten Linnemann
- Division of Immunology, Netherlands Cancer Institute, 1066 CX Amsterdam, the Netherlands; and
| | - Jan A J Geenevasen
- Van 't Hoff Institute for Molecular Sciences, University of Amsterdam, 1098 XH Amsterdam, the Netherlands
| | - Ton N M Schumacher
- Division of Immunology, Netherlands Cancer Institute, 1066 CX Amsterdam, the Netherlands; and
| | - Boris Rodenko
- Division of Cell Biology, Netherlands Cancer Institute, 1066 CX Amsterdam, the Netherlands;
| | - Huib Ovaa
- Division of Cell Biology, Netherlands Cancer Institute, 1066 CX Amsterdam, the Netherlands;
| |
Collapse
|
15
|
Navarro-Yepes J, Anandhan A, Bradley E, Bohovych I, Yarabe B, de Jong A, Ovaa H, Zhou Y, Khalimonchuk O, Quintanilla-Vega B, Franco R. Inhibition of Protein Ubiquitination by Paraquat and 1-Methyl-4-Phenylpyridinium Impairs Ubiquitin-Dependent Protein Degradation Pathways. Mol Neurobiol 2015; 53:5229-51. [PMID: 26409479 DOI: 10.1007/s12035-015-9414-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2015] [Accepted: 09/01/2015] [Indexed: 12/21/2022]
Abstract
Intracytoplasmic inclusions of protein aggregates in dopaminergic cells (Lewy bodies) are the pathological hallmark of Parkinson's disease (PD). Ubiquitin (Ub), alpha (α)-synuclein, p62/sequestosome 1, and oxidized proteins are the major components of Lewy bodies. However, the mechanisms involved in the impairment of misfolded/oxidized protein degradation pathways in PD are still unclear. PD is linked to mitochondrial dysfunction and environmental pesticide exposure. In this work, we evaluated the effects of the pesticide paraquat (PQ) and the mitochondrial toxin 1-methyl-4-phenylpyridinium (MPP(+)) on Ub-dependent protein degradation pathways. No increase in the accumulation of Ub-bound proteins or aggregates was observed in dopaminergic cells (SK-N-SH) treated with PQ or MPP(+), or in mice chronically exposed to PQ. PQ decreased Ub protein content, but not its mRNA transcription. Protein synthesis inhibition with cycloheximide depleted Ub levels and potentiated PQ-induced cell death. The inhibition of proteasomal activity by PQ was found to be a late event in cell death progression and had neither effect on the toxicity of either MPP(+) or PQ, nor on the accumulation of oxidized sulfenylated, sulfonylated (DJ-1/PARK7 and peroxiredoxins), and carbonylated proteins induced by PQ. PQ- and MPP(+)-induced Ub protein depletion prompted the dimerization/inactivation of the Ub-binding protein p62 that regulates the clearance of ubiquitinated proteins by autophagy. We confirmed that PQ and MPP(+) impaired autophagy flux and that the blockage of autophagy by the overexpression of a dominant-negative form of the autophagy protein 5 (dnAtg5) stimulated their toxicity, but there was no additional effect upon inhibition of the proteasome. PQ induced an increase in the accumulation of α-synuclein in dopaminergic cells and membrane-associated foci in yeast cells. Our results demonstrate that the inhibition of protein ubiquitination by PQ and MPP(+) is involved in the dysfunction of Ub-dependent protein degradation pathways.
Collapse
Affiliation(s)
- Juliana Navarro-Yepes
- Redox Biology Center, University of Nebraska-Lincoln, Lincoln, NE, USA.,School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, 114 VBS 0905, Lincoln, NE, 68583, USA.,Department of Toxicology, CINVESTAV-IPN, IPN No. 2508, Colonia Zacatenco, Mexico City, D.F., 07360, Mexico
| | - Annadurai Anandhan
- Redox Biology Center, University of Nebraska-Lincoln, Lincoln, NE, USA.,School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, 114 VBS 0905, Lincoln, NE, 68583, USA
| | - Erin Bradley
- Redox Biology Center, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Iryna Bohovych
- Redox Biology Center, University of Nebraska-Lincoln, Lincoln, NE, USA.,Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Bo Yarabe
- Redox Biology Center, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Annemieke de Jong
- Division of Cell Biology II, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Huib Ovaa
- Division of Cell Biology II, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - You Zhou
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Oleh Khalimonchuk
- Redox Biology Center, University of Nebraska-Lincoln, Lincoln, NE, USA.,Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Betzabet Quintanilla-Vega
- Department of Toxicology, CINVESTAV-IPN, IPN No. 2508, Colonia Zacatenco, Mexico City, D.F., 07360, Mexico.
| | - Rodrigo Franco
- Redox Biology Center, University of Nebraska-Lincoln, Lincoln, NE, USA. .,School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, 114 VBS 0905, Lincoln, NE, 68583, USA.
| |
Collapse
|
16
|
Berkers CR, de Jong A, Schuurman KG, Linnemann C, Meiring HD, Janssen L, Neefjes JJ, Schumacher TNM, Rodenko B, Ovaa H. Definition of Proteasomal Peptide Splicing Rules for High-Efficiency Spliced Peptide Presentation by MHC Class I Molecules. THE JOURNAL OF IMMUNOLOGY 2015; 195:4085-95. [PMID: 26401003 DOI: 10.4049/jimmunol.1402455] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Accepted: 08/24/2015] [Indexed: 11/19/2022]
Abstract
Peptide splicing, in which two distant parts of a protein are excised and then ligated to form a novel peptide, can generate unique MHC class I-restricted responses. Because these peptides are not genetically encoded and the rules behind proteasomal splicing are unknown, it is difficult to predict these spliced Ags. In the current study, small libraries of short peptides were used to identify amino acid sequences that affect the efficiency of this transpeptidation process. We observed that splicing does not occur at random, neither in terms of the amino acid sequences nor through random splicing of peptides from different sources. In contrast, splicing followed distinct rules that we deduced and validated both in vitro and in cells. Peptide ligation was quantified using a model peptide and demonstrated to occur with up to 30% ligation efficiency in vitro, provided that optimal structural requirements for ligation were met by both ligating partners. In addition, many splicing products could be formed from a single protein. Our splicing rules will facilitate prediction and detection of new spliced Ags to expand the peptidome presented by MHC class I Ags.
Collapse
Affiliation(s)
- Celia R Berkers
- Division of Cell Biology, Netherlands Cancer Institute, 1066 CX Amsterdam, the Netherlands
| | - Annemieke de Jong
- Division of Cell Biology, Netherlands Cancer Institute, 1066 CX Amsterdam, the Netherlands
| | - Karianne G Schuurman
- Division of Cell Biology, Netherlands Cancer Institute, 1066 CX Amsterdam, the Netherlands
| | - Carsten Linnemann
- Division of Immunology, Netherlands Cancer Institute, 1066 CX Amsterdam, the Netherlands; and
| | - Hugo D Meiring
- Institute for Translational Vaccinology, 3721 MA Bilthoven, the Netherlands
| | - Lennert Janssen
- Division of Cell Biology, Netherlands Cancer Institute, 1066 CX Amsterdam, the Netherlands
| | - Jacques J Neefjes
- Division of Cell Biology, Netherlands Cancer Institute, 1066 CX Amsterdam, the Netherlands
| | - Ton N M Schumacher
- Division of Immunology, Netherlands Cancer Institute, 1066 CX Amsterdam, the Netherlands; and
| | - Boris Rodenko
- Division of Cell Biology, Netherlands Cancer Institute, 1066 CX Amsterdam, the Netherlands
| | - Huib Ovaa
- Division of Cell Biology, Netherlands Cancer Institute, 1066 CX Amsterdam, the Netherlands;
| |
Collapse
|
17
|
Deschênes-Simard X, Lessard F, Gaumont-Leclerc MF, Bardeesy N, Ferbeyre G. Cellular senescence and protein degradation: breaking down cancer. Cell Cycle 2014; 13:1840-58. [PMID: 24866342 DOI: 10.4161/cc.29335] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Autophagy and the ubiquitin-proteasome pathway (UPP) are the major protein degradation systems in eukaryotic cells. Whereas the former mediate a bulk nonspecific degradation, the UPP allows a rapid degradation of specific proteins. Both systems have been shown to play a role in tumorigenesis, and the interest in developing therapeutic agents inhibiting protein degradation is steadily growing. However, emerging data point to a critical role for autophagy in cellular senescence, an established tumor suppressor mechanism. Recently, a selective protein degradation process mediated by the UPP was also shown to contribute to the senescence phenotype. This process is tightly regulated by E3 ubiquitin ligases, deubiquitinases, and several post-translational modifications of target proteins. Illustrating the complexity of UPP, more than 600 human genes have been shown to encode E3 ubiquitin ligases, a number which exceeds that of the protein kinases. Nevertheless, our knowledge of proteasome-dependent protein degradation as a regulated process in cellular contexts such as cancer and senescence remains very limited. Here we discuss the implications of protein degradation in senescence and attempt to relate this function to the protein degradation pattern observed in cancer cells.
Collapse
Affiliation(s)
- Xavier Deschênes-Simard
- Department of Biochemistry and Molecular Medicine; Université de Montréal; Montréal, Québec, Canada
| | - Frédéric Lessard
- Department of Biochemistry and Molecular Medicine; Université de Montréal; Montréal, Québec, Canada
| | | | - Nabeel Bardeesy
- Massachusetts General Hospital Cancer Center; Harvard Medical School; Boston, MA USA
| | - Gerardo Ferbeyre
- Department of Biochemistry and Molecular Medicine; Université de Montréal; Montréal, Québec, Canada
| |
Collapse
|
18
|
Abstract
Over the years, the proteasome has been extensively investigated due to its crucial roles in many important signaling pathways and its implications in diseases. Two proteasome inhibitors--bortezomib and carfilzomib--have received FDA approval for the treatment of multiple myeloma, thereby validating the proteasome as a chemotherapeutic target. As a result, further research efforts have been focused on dissecting the complex biology of the proteasome to gain the insight required for developing next-generation proteasome inhibitors. It is clear that chemical probes have made significant contributions to these efforts, mostly by functioning as inhibitors that selectively block the catalytic activity of proteasomes. Analogues of these inhibitors are now providing additional tools for visualization of catalytically active proteasome subunits, several of which allow real-time monitoring of proteasome activity in living cells as well as in in vivo settings. These imaging probes will provide powerful tools for assessing the efficacy of proteasome inhibitors in clinical settings. In this review, we will focus on the recent efforts towards developing imaging probes of proteasomes, including the latest developments in immunoproteasome-selective imaging probes.
Collapse
|