1
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Moses D, Guadalupe K, Yu F, Flores E, Perez AR, McAnelly R, Shamoon NM, Kaur G, Cuevas-Zepeda E, Merg AD, Martin EW, Holehouse AS, Sukenik S. Structural biases in disordered proteins are prevalent in the cell. Nat Struct Mol Biol 2024; 31:283-292. [PMID: 38177684 PMCID: PMC10873198 DOI: 10.1038/s41594-023-01148-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 10/04/2023] [Indexed: 01/06/2024]
Abstract
Intrinsically disordered proteins and protein regions (IDPs) are prevalent in all proteomes and are essential to cellular function. Unlike folded proteins, IDPs exist in an ensemble of dissimilar conformations. Despite this structural plasticity, intramolecular interactions create sequence-specific structural biases that determine an IDP ensemble's three-dimensional shape. Such structural biases can be key to IDP function and are often measured in vitro, but whether those biases are preserved inside the cell is unclear. Here we show that structural biases in IDP ensembles found in vitro are recapitulated inside human-derived cells. We further reveal that structural biases can change in a sequence-dependent manner due to changes in the intracellular milieu, subcellular localization, and intramolecular interactions with tethered well-folded domains. We propose that the structural sensitivity of IDP ensembles can be leveraged for biological function, can be the underlying cause of IDP-driven pathology or can be used to design disorder-based biosensors and actuators.
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Affiliation(s)
- David Moses
- Department of Chemistry and Biochemistry, University of California, Merced, Merced, CA, USA
- Center for Cellular and Biomolecular Machines, University of California, Merced, Merced, CA, USA
| | - Karina Guadalupe
- Department of Chemistry and Biochemistry, University of California, Merced, Merced, CA, USA
- Center for Cellular and Biomolecular Machines, University of California, Merced, Merced, CA, USA
| | - Feng Yu
- Center for Cellular and Biomolecular Machines, University of California, Merced, Merced, CA, USA
- Quantitative and Systems Biology Program, University of California, Merced, Merced, CA, USA
| | - Eduardo Flores
- Department of Chemistry and Biochemistry, University of California, Merced, Merced, CA, USA
- Center for Cellular and Biomolecular Machines, University of California, Merced, Merced, CA, USA
| | - Anthony R Perez
- Department of Chemistry and Biochemistry, University of California, Merced, Merced, CA, USA
- Center for Cellular and Biomolecular Machines, University of California, Merced, Merced, CA, USA
| | - Ralph McAnelly
- Department of Chemistry and Biochemistry, University of California, Merced, Merced, CA, USA
| | - Nora M Shamoon
- Center for Cellular and Biomolecular Machines, University of California, Merced, Merced, CA, USA
- California State University, Stanislaus, Turlock, CA, USA
| | - Gagandeep Kaur
- Department of Chemistry and Biochemistry, University of California, Merced, Merced, CA, USA
| | | | - Andrea D Merg
- Department of Chemistry and Biochemistry, University of California, Merced, Merced, CA, USA
- Center for Cellular and Biomolecular Machines, University of California, Merced, Merced, CA, USA
| | - Erik W Martin
- Department of Structural Biology, St Jude Children's Research Hospital, Memphis, TN, USA
- Dewpoint Therapeutics, Boston, MA, USA
| | - Alex S Holehouse
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, USA
- Center for Science and Engineering of Living Systems, Washington University in St. Louis, St. Louis, MO, USA
| | - Shahar Sukenik
- Department of Chemistry and Biochemistry, University of California, Merced, Merced, CA, USA.
- Center for Cellular and Biomolecular Machines, University of California, Merced, Merced, CA, USA.
- Quantitative and Systems Biology Program, University of California, Merced, Merced, CA, USA.
- Health Sciences Research Institute, University of California, Merced, Merced, CA, USA.
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2
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Nagel A, Leonard M, Maurus I, Starke J, Schmitt K, Valerius O, Harting R, Braus GH. The Frq-Frh Complex Light-Dependently Delays Sfl1-Induced Microsclerotia Formation in Verticillium dahliae. J Fungi (Basel) 2023; 9:725. [PMID: 37504714 PMCID: PMC10381341 DOI: 10.3390/jof9070725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 06/19/2023] [Accepted: 06/28/2023] [Indexed: 07/29/2023] Open
Abstract
The vascular plant pathogenic fungus Verticillium dahliae has to adapt to environmental changes outside and inside its host. V. dahliae harbors homologs of Neurospora crassa clock genes. The molecular functions and interactions of Frequency (Frq) and Frq-interacting RNA helicase (Frh) in controlling conidia or microsclerotia development were investigated in V. dahliae JR2. Fungal mutant strains carrying clock gene deletions, an FRH point mutation, or GFP gene fusions were analyzed on transcript, protein, and phenotypic levels as well as in pathogenicity assays on tomato plants. Our results support that the Frq-Frh complex is formed and that it promotes conidiation, but also that it suppresses and therefore delays V. dahliae microsclerotia formation in response to light. We investigated a possible link between the negative element Frq and positive regulator Suppressor of flocculation 1 (Sfl1) in microsclerotia formation to elucidate the regulatory molecular mechanism. Both Frq and Sfl1 are mainly present during the onset of microsclerotia formation with decreasing protein levels during further development. Induction of microsclerotia formation requires Sfl1 and can be delayed at early time points in the light through the Frq-Frh complex. Gaining further molecular knowledge on V. dahliae development will improve control of fungal growth and Verticillium wilt disease.
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Affiliation(s)
- Alexandra Nagel
- Department of Molecular Microbiology and Genetics, Institute of Microbiology and Genetics and Göttingen Center for Molecular Biosciences (GZMB), University of Göttingen, Grisebachstr. 8, D-37077 Göttingen, Germany
| | - Miriam Leonard
- Department of Molecular Microbiology and Genetics, Institute of Microbiology and Genetics and Göttingen Center for Molecular Biosciences (GZMB), University of Göttingen, Grisebachstr. 8, D-37077 Göttingen, Germany
| | - Isabel Maurus
- Department of Molecular Microbiology and Genetics, Institute of Microbiology and Genetics and Göttingen Center for Molecular Biosciences (GZMB), University of Göttingen, Grisebachstr. 8, D-37077 Göttingen, Germany
| | - Jessica Starke
- Department of Molecular Microbiology and Genetics, Institute of Microbiology and Genetics and Göttingen Center for Molecular Biosciences (GZMB), University of Göttingen, Grisebachstr. 8, D-37077 Göttingen, Germany
| | - Kerstin Schmitt
- Department of Molecular Microbiology and Genetics, Institute of Microbiology and Genetics and Göttingen Center for Molecular Biosciences (GZMB), University of Göttingen, Grisebachstr. 8, D-37077 Göttingen, Germany
| | - Oliver Valerius
- Department of Molecular Microbiology and Genetics, Institute of Microbiology and Genetics and Göttingen Center for Molecular Biosciences (GZMB), University of Göttingen, Grisebachstr. 8, D-37077 Göttingen, Germany
| | - Rebekka Harting
- Department of Molecular Microbiology and Genetics, Institute of Microbiology and Genetics and Göttingen Center for Molecular Biosciences (GZMB), University of Göttingen, Grisebachstr. 8, D-37077 Göttingen, Germany
| | - Gerhard H Braus
- Department of Molecular Microbiology and Genetics, Institute of Microbiology and Genetics and Göttingen Center for Molecular Biosciences (GZMB), University of Göttingen, Grisebachstr. 8, D-37077 Göttingen, Germany
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3
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Deshmukh FK, Ben-Nissan G, Olshina MA, Füzesi-Levi MG, Polkinghorn C, Arkind G, Leushkin Y, Fainer I, Fleishman SJ, Tawfik D, Sharon M. Allosteric regulation of the 20S proteasome by the Catalytic Core Regulators (CCRs) family. Nat Commun 2023; 14:3126. [PMID: 37253751 DOI: 10.1038/s41467-023-38404-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 04/26/2023] [Indexed: 06/01/2023] Open
Abstract
Controlled degradation of proteins is necessary for ensuring their abundance and sustaining a healthy and accurately functioning proteome. One of the degradation routes involves the uncapped 20S proteasome, which cleaves proteins with a partially unfolded region, including those that are damaged or contain intrinsically disordered regions. This degradation route is tightly controlled by a recently discovered family of proteins named Catalytic Core Regulators (CCRs). Here, we show that CCRs function through an allosteric mechanism, coupling the physical binding of the PSMB4 β-subunit with attenuation of the complex's three proteolytic activities. In addition, by dissecting the structural properties that are required for CCR-like function, we could recapitulate this activity using a designed protein that is half the size of natural CCRs. These data uncover an allosteric path that does not involve the proteasome's enzymatic subunits but rather propagates through the non-catalytic subunit PSMB4. This way of 20S proteasome-specific attenuation opens avenues for decoupling the 20S and 26S proteasome degradation pathways as well as for developing selective 20S proteasome inhibitors.
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Affiliation(s)
- Fanindra Kumar Deshmukh
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Gili Ben-Nissan
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Maya A Olshina
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Maria G Füzesi-Levi
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Caley Polkinghorn
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Galina Arkind
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Yegor Leushkin
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Irit Fainer
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Sarel J Fleishman
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Dan Tawfik
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Michal Sharon
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, 7610001, Israel.
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4
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Biran A, Myers N, Steinberger S, Adler J, Riutin M, Broennimann K, Reuven N, Shaul Y. The C-Terminus of the PSMA3 Proteasome Subunit Preferentially Traps Intrinsically Disordered Proteins for Degradation. Cells 2022; 11:cells11203231. [PMID: 36291102 PMCID: PMC9600399 DOI: 10.3390/cells11203231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 10/02/2022] [Accepted: 10/10/2022] [Indexed: 12/29/2022] Open
Abstract
The degradation of intrinsically disordered proteins (IDPs) by a non-26S proteasome process does not require proteasomal targeting by polyubiquitin. However, whether and how IDPs are recognized by the non-26S proteasome, including the 20S complex, remains unknown. Analyses of protein interactome datasets revealed that the 20S proteasome subunit, PSMA3, preferentially interacts with many IDPs. In vivo and cell-free experiments revealed that the C-terminus of PSMA3, a 69-amino-acids-long fragment, is an IDP trapper. A recombinant trapper is sufficient to interact with many IDPs, and blocks IDP degradation in vitro by the 20S proteasome, possibly by competing with the native trapper. In addition, over a third of the PSMA3 trapper-binding proteins have previously been identified as 20S proteasome substrates and, based on published datasets, many of the trapper-binding proteins are associated with the intracellular proteasomes. The PSMA3-trapped IDPs that are proteasome substrates have the unique features previously recognized as characteristic 20S proteasome substrates in vitro. We propose a model whereby the PSMA3 C-terminal region traps a subset of IDPs to facilitate their proteasomal degradation.
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5
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Enenkel C, Kang RW, Wilfling F, Ernst OP. Intracellular localization of the proteasome in response to stress conditions. J Biol Chem 2022; 298:102083. [PMID: 35636514 PMCID: PMC9218506 DOI: 10.1016/j.jbc.2022.102083] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 05/13/2022] [Accepted: 05/16/2022] [Indexed: 12/15/2022] Open
Abstract
The ubiquitin–proteasome system fulfills an essential role in regulating protein homeostasis by spatially and temporally controlling proteolysis in an ATP- and ubiquitin-dependent manner. However, the localization of proteasomes is highly variable under diverse cellular conditions. In yeast, newly synthesized proteasomes are primarily localized to the nucleus during cell proliferation. Yeast proteasomes are transported into the nucleus through the nuclear pore either as immature subcomplexes or as mature enzymes via adapter proteins Sts1 and Blm10, while in mammalian cells, postmitotic uptake of proteasomes into the nucleus is mediated by AKIRIN2, an adapter protein essentially required for nuclear protein degradation. Stressful growth conditions and the reversible halt of proliferation, that is quiescence, are associated with a decline in ATP and the reorganization of proteasome localization. Cellular stress leads to proteasome accumulation in membraneless granules either in the nucleus or in the cytoplasm. In quiescence, yeast proteasomes are sequestered in an ubiquitin-dependent manner into motile and reversible proteasome storage granules in the cytoplasm. In cancer cells, upon amino acid deprivation, heat shock, osmotic stress, oxidative stress, or the inhibition of either proteasome activity or nuclear export, reversible proteasome foci containing polyubiquitinated substrates are formed by liquid–liquid phase separation in the nucleus. In this review, we summarize recent literature revealing new links between nuclear transport, ubiquitin signaling, and the intracellular organization of proteasomes during cellular stress conditions.
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Affiliation(s)
- Cordula Enenkel
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada.
| | - Ryu Won Kang
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Florian Wilfling
- Mechanisms of Cellular Quality Control, Max-Planck-Institute of Biophysics, Frankfurt, Germany
| | - Oliver P Ernst
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada; Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
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6
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Guharoy M, Lazar T, Macossay-Castillo M, Tompa P. Degron masking outlines degronons, co-degrading functional modules in the proteome. Commun Biol 2022; 5:445. [PMID: 35545699 PMCID: PMC9095673 DOI: 10.1038/s42003-022-03391-z] [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: 01/19/2021] [Accepted: 04/22/2022] [Indexed: 11/28/2022] Open
Abstract
Effective organization of proteins into functional modules (networks, pathways) requires systems-level coordination between transcription, translation and degradation. Whereas the cooperation between transcription and translation was extensively studied, the cooperative degradation regulation of protein complexes and pathways has not been systematically assessed. Here we comprehensively analyzed degron masking, a major mechanism by which cellular systems coordinate degron recognition and protein degradation. For over 200 substrates with characterized degrons (E3 ligase targeting motifs, ubiquitination sites and disordered proteasomal entry sequences), we demonstrate that degrons extensively overlap with protein-protein interaction sites. Analysis of binding site information and protein abundance comparisons show that regulatory partners effectively outcompete E3 ligases, masking degrons from the ubiquitination machinery. Protein abundance variations between normal and cancer cells highlight the dynamics of degron masking components. Finally, integrative analysis of gene co-expression, half-life correlations and functional relationships between interacting proteins point towards higher-order, co-regulated degradation modules (‘degronons’) in the proteome. Systematic bioinformatics analysis of cooperative degradation of protein complexes indicates that degrons extensively overlap with protein-protein interaction sites, hiding degrons from ubiquitination machinery and suggesting the existence of co-degrading functional modules in the proteome.
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Affiliation(s)
- Mainak Guharoy
- VIB-VUB Center for Structural Biology, Pleinlaan 2, 1050, Brussels, Belgium. .,Structural Biology Brussels, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels, Belgium. .,VIB Bioinformatics Core, Technologiepark-Zwijnaarde 75, 9052, Ghent, Belgium.
| | - Tamas Lazar
- VIB-VUB Center for Structural Biology, Pleinlaan 2, 1050, Brussels, Belgium.,Structural Biology Brussels, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels, Belgium
| | - Mauricio Macossay-Castillo
- VIB-VUB Center for Structural Biology, Pleinlaan 2, 1050, Brussels, Belgium.,Structural Biology Brussels, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels, Belgium
| | - Peter Tompa
- VIB-VUB Center for Structural Biology, Pleinlaan 2, 1050, Brussels, Belgium. .,Structural Biology Brussels, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels, Belgium. .,Institute of Enzymology, Research Centre for Natural Sciences of the Hungarian Academy of Sciences, 1117, Budapest, Hungary.
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7
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Kim SJ, Woo Y, Kim HJ, Goo BS, Nhung TTM, Lee SA, Suh BK, Mun DJ, Kim JH, Park SK. Retinoic acid-induced protein 14 controls dendritic spine dynamics associated with depressive-like behaviors. eLife 2022; 11:77755. [PMID: 35467532 PMCID: PMC9068211 DOI: 10.7554/elife.77755] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 04/24/2022] [Indexed: 11/24/2022] Open
Abstract
Dendritic spines are the central postsynaptic machinery that determines synaptic function. The F-actin within dendritic spines regulates their dynamic formation and elimination. Rai14 is an F-actin-regulating protein with a membrane-shaping function. Here, we identified the roles of Rai14 for the regulation of dendritic spine dynamics associated with stress-induced depressive-like behaviors. Rai14-deficient neurons exhibit reduced dendritic spine density in the Rai14+/- mouse brain, resulting in impaired functional synaptic activity. Rai14 was protected from degradation by complex formation with Tara, and accumulated in the dendritic spine neck, thereby enhancing spine maintenance. Concurrently, Rai14 deficiency in mice altered gene expression profile relevant to depressive conditions and increased depressive-like behaviors. Moreover, Rai14 expression was reduced in the prefrontal cortex of the mouse stress model, which was blocked by antidepressant treatment. Thus, we propose that Rai14-dependent regulation of dendritic spines may underlie the plastic changes of neuronal connections relevant to depressive-like behaviors.
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Affiliation(s)
- Soo Jeong Kim
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Youngsik Woo
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Hyun Jin Kim
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Bon Seong Goo
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Truong Thi My Nhung
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Seol-Ae Lee
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Bo Kyoung Suh
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Dong Jin Mun
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Joung-Hun Kim
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Sang Ki Park
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Republic of Korea
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8
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Bonhoure A, Henry L, Bich C, Blanc L, Bergeret B, Bousquet M, Coux O, Stoebner P, Vidal M. Extracellular
20S
proteasome secreted via microvesicles can degrade poorly folded proteins and inhibit Galectin‐3 agglutination activity. Traffic 2022; 23:287-304. [DOI: 10.1111/tra.12840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 02/22/2022] [Accepted: 02/23/2022] [Indexed: 11/30/2022]
Affiliation(s)
- Anne Bonhoure
- Laboratory of Pathogen Host Interactions Université Montpellier, CNRS Montpellier France
| | - Laurent Henry
- Institut des Biomolécules Max Mousseron Université Montpellier, CNRS Montpellier France
| | - Claudia Bich
- Institut des Biomolécules Max Mousseron Université Montpellier, CNRS Montpellier France
| | - Lionel Blanc
- The Feinstein Institutes for Medical Research Manhasset New York USA
| | - Blanche Bergeret
- Institut des Biomolécules Max Mousseron Université Montpellier, CNRS Montpellier France
| | - Marie‐Pierre Bousquet
- Institut de Pharmacologie et de Biologie Structurale Université Toulouse, CNRS, UPS Toulouse France
| | - Olivier Coux
- Centre de Recherche en Biologie cellulaire de Montpellier Univ. Montpellier, CNRS Montpellier France
| | - Pierre‐Emmanuel Stoebner
- Service de Dermatologie, CHU Nîmes Nîmes France
- Institut de Recherche en Cancérologie de Montpellier (IRCM) Université Montpellier Montpellier France
| | - Michel Vidal
- Laboratory of Pathogen Host Interactions Université Montpellier, CNRS Montpellier France
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9
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Abstract
This mini-review represents a brief, disorder-centric consideration of the interplay between order and disorder in proteins. The goal here is to show that inside the cell, folding, non-folding, and misfolding of proteins are interlinked on multiple levels. This is evidenced by the highly heterogeneous spatio-temporal structural organization of a protein molecule, where one can find differently (dis)ordered components that can undergo local or global order-to-disorder and disorder-to-order transitions needed for functionality. This is further illustrated by the fact that at particular moments of their life, most notably during their synthesis and degradation, all proteins are at least partially disordered. In addition to these intrinsic forms of disorder, proteins are constantly facing extrinsic disorder, which is intrinsic disorder in their functional partners. All this comprises the multileveled protein disorder cycle.
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Affiliation(s)
- Vladimir N Uversky
- Department of Molecular Medicine and Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL 33612 USA
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10
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Frayssinhes JYA, Cerruti F, Laulin J, Cattaneo A, Bachi A, Apcher S, Coux O, Cascio P. PA28γ-20S proteasome is a proteolytic complex committed to degrade unfolded proteins. Cell Mol Life Sci 2021; 79:45. [PMID: 34913092 PMCID: PMC11071804 DOI: 10.1007/s00018-021-04045-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 11/15/2021] [Accepted: 11/17/2021] [Indexed: 02/07/2023]
Abstract
PA28γ is a nuclear activator of the 20S proteasome that, unlike the 19S regulatory particle, stimulates hydrolysis of several substrates in an ATP- and ubiquitin-independent manner and whose exact biological functions and molecular mechanism of action still remain elusive. In an effort to shed light on these important issues, we investigated the stimulatory effect of PA28γ on the hydrolysis of different fluorogenic peptides and folded or denatured full-length proteins by the 20S proteasome. Importantly, PA28γ was found to dramatically enhance breakdown rates by 20S proteasomes of several naturally or artificially unstructured proteins, but not of their native, folded counterparts. Furthermore, these data were corroborated by experiments in cell lines with a nucleus-tagged myelin basic protein. Finally, mass spectrometry analysis of the products generated during proteasomal degradation of two proteins demonstrated that PA28γ does not increase, but rather decreases, the variability of peptides that are potentially suitable for MHC class I antigen presentation. These unexpected findings indicate that global stimulation of the degradation of unfolded proteins may represent a more general feature of PA28γ and suggests that this proteasomal activator might play a broader role in the pathway of protein degradation than previously believed.
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Affiliation(s)
| | - Fulvia Cerruti
- Department of Veterinary Sciences, University of Turin, Largo P. Braccini 2, 10095, Grugliasco, Turin, Italy
| | - Justine Laulin
- Université Paris-Saclay, Institut Gustave Roussy, Inserm, Immunologie Des Tumeurs et Immunothérapie, Villejuif, France
| | | | - Angela Bachi
- The FIRC Institute of Molecular Oncology (IFOM), 20139, Milan, Italy
| | - Sebastien Apcher
- Université Paris-Saclay, Institut Gustave Roussy, Inserm, Immunologie Des Tumeurs et Immunothérapie, Villejuif, France
| | - Olivier Coux
- Centre de Recherche de Biologie Cellulaire de Montpellier (CRBM), CNRS UMR 5237, Université de Montpellier, 1919 Route de Mende, 34293, Montpellier, France
| | - Paolo Cascio
- Department of Veterinary Sciences, University of Turin, Largo P. Braccini 2, 10095, Grugliasco, Turin, Italy.
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11
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George DE, Tepe JJ. Advances in Proteasome Enhancement by Small Molecules. Biomolecules 2021; 11:1789. [PMID: 34944433 PMCID: PMC8699248 DOI: 10.3390/biom11121789] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 11/23/2021] [Accepted: 11/26/2021] [Indexed: 01/11/2023] Open
Abstract
The proteasome system is a large and complex molecular machinery responsible for the degradation of misfolded, damaged, and redundant cellular proteins. When proteasome function is impaired, unwanted proteins accumulate, which can lead to several diseases including age-related and neurodegenerative diseases. Enhancing proteasome-mediated substrate degradation with small molecules may therefore be a valuable strategy for the treatment of various neurodegenerative diseases such as Parkinson's, Alzheimer's, and Huntington's diseases. In this review, we discuss the structure of proteasome and how proteasome's proteolytic activity is associated with aging and various neurodegenerative diseases. We also summarize various classes of compounds that are capable of enhancing, directly or indirectly, proteasome-mediated protein degradation.
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Affiliation(s)
| | - Jetze J. Tepe
- Department of Chemistry and Pharmacology & Toxicology, Michigan State University, East Lansing, MI 48824, USA;
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12
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Cascio P. PA28γ: New Insights on an Ancient Proteasome Activator. Biomolecules 2021; 11:228. [PMID: 33562807 PMCID: PMC7915322 DOI: 10.3390/biom11020228] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2021] [Revised: 02/02/2021] [Accepted: 02/03/2021] [Indexed: 02/06/2023] Open
Abstract
PA28 (also known as 11S, REG or PSME) is a family of proteasome regulators whose members are widely present in many of the eukaryotic supergroups. In jawed vertebrates they are represented by three paralogs, PA28α, PA28β, and PA28γ, which assemble as heptameric hetero (PA28αβ) or homo (PA28γ) rings on one or both extremities of the 20S proteasome cylindrical structure. While they share high sequence and structural similarities, the three isoforms significantly differ in terms of their biochemical and biological properties. In fact, PA28α and PA28β seem to have appeared more recently and to have evolved very rapidly to perform new functions that are specifically aimed at optimizing the process of MHC class I antigen presentation. In line with this, PA28αβ favors release of peptide products by proteasomes and is particularly suited to support adaptive immune responses without, however, affecting hydrolysis rates of protein substrates. On the contrary, PA28γ seems to be a slow-evolving gene that is most similar to the common ancestor of the PA28 activators family, and very likely retains its original functions. Notably, PA28γ has a prevalent nuclear localization and is involved in the regulation of several essential cellular processes including cell growth and proliferation, apoptosis, chromatin structure and organization, and response to DNA damage. In striking contrast with the activity of PA28αβ, most of these diverse biological functions of PA28γ seem to depend on its ability to markedly enhance degradation rates of regulatory protein by 20S proteasome. The present review will focus on the molecular mechanisms and biochemical properties of PA28γ, which are likely to account for its various and complex biological functions and highlight the common features with the PA28αβ paralog.
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Affiliation(s)
- Paolo Cascio
- Department of Veterinary Sciences, University of Turin, Largo P. Braccini 2, 10095 Grugliasco, Italy
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13
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Structural Insights into Substrate Recognition and Processing by the 20S Proteasome. Biomolecules 2021; 11:biom11020148. [PMID: 33498876 PMCID: PMC7910952 DOI: 10.3390/biom11020148] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Revised: 01/18/2021] [Accepted: 01/21/2021] [Indexed: 12/12/2022] Open
Abstract
Four decades of proteasome research have yielded extensive information on ubiquitin-dependent proteolysis. The archetype of proteasomes is a 20S barrel-shaped complex that does not rely on ubiquitin as a degradation signal but can degrade substrates with a considerable unstructured stretch. Since roughly half of all proteasomes in most eukaryotic cells are free 20S complexes, ubiquitin-independent protein degradation may coexist with ubiquitin-dependent degradation by the highly regulated 26S proteasome. This article reviews recent advances in our understanding of the biochemical and structural features that underlie the proteolytic mechanism of 20S proteasomes. The two outer α-rings of 20S proteasomes provide a number of potential docking sites for loosely folded polypeptides. The binding of a substrate can induce asymmetric conformational changes, trigger gate opening, and initiate its own degradation through a protease-driven translocation mechanism. Consequently, the substrate translocates through two additional narrow apertures augmented by the β-catalytic active sites. The overall pulling force through the two annuli results in a protease-like unfolding of the substrate and subsequent proteolysis in the catalytic chamber. Although both proteasomes contain identical β-catalytic active sites, the differential translocation mechanisms yield distinct peptide products. Nonoverlapping substrate repertoires and product outcomes rationalize cohabitation of both proteasome complexes in cells.
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14
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Pelham JF, Dunlap JC, Hurley JM. Intrinsic disorder is an essential characteristic of components in the conserved circadian circuit. Cell Commun Signal 2020; 18:181. [PMID: 33176800 PMCID: PMC7656774 DOI: 10.1186/s12964-020-00658-y] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 09/06/2020] [Indexed: 12/12/2022] Open
Abstract
INTRODUCTION The circadian circuit, a roughly 24 h molecular feedback loop, or clock, is conserved from bacteria to animals and allows for enhanced organismal survival by facilitating the anticipation of the day/night cycle. With circadian regulation reportedly impacting as high as 80% of protein coding genes in higher eukaryotes, the protein-based circadian clock broadly regulates physiology and behavior. Due to the extensive interconnection between the clock and other cellular systems, chronic disruption of these molecular rhythms leads to a decrease in organismal fitness as well as an increase of disease rates in humans. Importantly, recent research has demonstrated that proteins comprising the circadian clock network display a significant amount of intrinsic disorder. MAIN BODY In this work, we focus on the extent of intrinsic disorder in the circadian clock and its potential mechanistic role in circadian timing. We highlight the conservation of disorder by quantifying the extent of computationally-predicted protein disorder in the core clock of the key eukaryotic circadian model organisms Drosophila melanogaster, Neurospora crassa, and Mus musculus. We further examine previously published work, as well as feature novel experimental evidence, demonstrating that the core negative arm circadian period drivers FREQUENCY (Neurospora crassa) and PERIOD-2 (PER2) (Mus musculus), possess biochemical characteristics of intrinsically disordered proteins. Finally, we discuss the potential contributions of the inherent biophysical principals of intrinsically disordered proteins that may explain the vital mechanistic roles they play in the clock to drive their broad evolutionary conservation in circadian timekeeping. CONCLUSION The pervasive conservation of disorder amongst the clock in the crown eukaryotes suggests that disorder is essential for optimal circadian timing from fungi to animals, providing vital homeostatic cellular maintenance and coordinating organismal physiology across phylogenetic kingdoms. Video abstract.
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Affiliation(s)
- Jacqueline F. Pelham
- Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, NY 12180 USA
| | - Jay C. Dunlap
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755 USA
| | - Jennifer M. Hurley
- Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, NY 12180 USA
- Center for Biotechnology and Interdisciplinary Sciences, Rensselaer Polytechnic Institute, Troy, NY 12018 USA
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15
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Hao J, Yang X, Zhang C, Zhang XT, Shi M, Wang SH, Mi L, Zhao YT, Cao H, Wang Y. KLF3 promotes the 8-cell-like transcriptional state in pluripotent stem cells. Cell Prolif 2020; 53:e12914. [PMID: 32990380 PMCID: PMC7653263 DOI: 10.1111/cpr.12914] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 09/05/2020] [Accepted: 09/06/2020] [Indexed: 12/16/2022] Open
Abstract
OBJECTIVES Mouse embryonic stem cell (mESC) culture contains various heterogeneous populations, which serve as excellent models to study gene regulation in early embryo development. The heterogeneity is typically defined by transcriptional activities, for example, the expression of Nanog or Rex1 mRNA. Our objectives were to identify mESC heterogeneity that are caused by mechanisms other than transcriptional control. MATERIALS AND METHODS Klf3 mRNA and protein were analysed by RT-qPCR, Western blotting or immunofluorescence in mESCs, C2C12 cells, early mouse embryos and various mouse tissues. An ESC reporter line expressing KLF3-GFP fusion protein was made to study heterogeneity of KLF3 protein expression in ESCs. GFP-positive mESCs were sorted for further analysis including RT-qPCR and RNA-seq. RESULTS In the majority of mESCs, KLF3 protein is actively degraded due to its proline-rich sequence and highly disordered structure. Interestingly, KLF3 protein is stabilized in a small subset of mESCs. Transcriptome analysis indicates that KLF3-positive mESCs upregulate genes that are initially activated in 8-cell embryos. Consistently, KLF3 protein but not mRNA is dramatically increased in 8-cell embryos. Forced expression of KLF3 protein in mESCs promotes the expression of 8-cell-embryo activated genes. CONCLUSIONS Our study identifies previously unrecognized heterogeneity due to KLF3 protein expression in mESCs.
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Affiliation(s)
- Jing Hao
- Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, Peking University, Beijing, China
| | - Xi Yang
- Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, Peking University, Beijing, China
| | - Chao Zhang
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Xue-Tao Zhang
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Ming Shi
- Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, Peking University, Beijing, China
| | - Shao-Hua Wang
- Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, Peking University, Beijing, China
| | - Li Mi
- Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, Peking University, Beijing, China
| | - Yu-Ting Zhao
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Huiqing Cao
- Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, Peking University, Beijing, China
| | - Yangming Wang
- Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, Peking University, Beijing, China
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16
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Kubatova N, Pyper DJ, Jonker HRA, Saxena K, Remmel L, Richter C, Brantl S, Evguenieva‐Hackenberg E, Hess WR, Klug G, Marchfelder A, Soppa J, Streit W, Mayzel M, Orekhov VY, Fuxreiter M, Schmitz RA, Schwalbe H. Rapid Biophysical Characterization and NMR Spectroscopy Structural Analysis of Small Proteins from Bacteria and Archaea. Chembiochem 2020; 21:1178-1187. [PMID: 31705614 PMCID: PMC7217052 DOI: 10.1002/cbic.201900677] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Indexed: 01/08/2023]
Abstract
Proteins encoded by small open reading frames (sORFs) have a widespread occurrence in diverse microorganisms and can be of high functional importance. However, due to annotation biases and their technically challenging direct detection, these small proteins have been overlooked for a long time and were only recently rediscovered. The currently rapidly growing number of such proteins requires efficient methods to investigate their structure-function relationship. Herein, a method is presented for fast determination of the conformational properties of small proteins. Their small size makes them perfectly amenable for solution-state NMR spectroscopy. NMR spectroscopy can provide detailed information about their conformational states (folded, partially folded, and unstructured). In the context of the priority program on small proteins funded by the German research foundation (SPP2002), 27 small proteins from 9 different bacterial and archaeal organisms have been investigated. It is found that most of these small proteins are unstructured or partially folded. Bioinformatics tools predict that some of these unstructured proteins can potentially fold upon complex formation. A protocol for fast NMR spectroscopy structure elucidation is described for the small proteins that adopt a persistently folded structure by implementation of new NMR technologies, including automated resonance assignment and nonuniform sampling in combination with targeted acquisition.
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Affiliation(s)
- Nina Kubatova
- Institute for Organic Chemistry and Chemical BiologyCenter for Biomolecular Magnetic Resonance (BMRZ)Johann Wolfgang Goethe UniversityMax-von-Laue-Strasse 760438Frankfurt/MainGermany
| | - Dennis J. Pyper
- Institute for Organic Chemistry and Chemical BiologyCenter for Biomolecular Magnetic Resonance (BMRZ)Johann Wolfgang Goethe UniversityMax-von-Laue-Strasse 760438Frankfurt/MainGermany
| | - Hendrik R. A. Jonker
- Institute for Organic Chemistry and Chemical BiologyCenter for Biomolecular Magnetic Resonance (BMRZ)Johann Wolfgang Goethe UniversityMax-von-Laue-Strasse 760438Frankfurt/MainGermany
| | - Krishna Saxena
- Institute for Organic Chemistry and Chemical BiologyCenter for Biomolecular Magnetic Resonance (BMRZ)Johann Wolfgang Goethe UniversityMax-von-Laue-Strasse 760438Frankfurt/MainGermany
| | - Laura Remmel
- Institute for Organic Chemistry and Chemical BiologyCenter for Biomolecular Magnetic Resonance (BMRZ)Johann Wolfgang Goethe UniversityMax-von-Laue-Strasse 760438Frankfurt/MainGermany
| | - Christian Richter
- Institute for Organic Chemistry and Chemical BiologyCenter for Biomolecular Magnetic Resonance (BMRZ)Johann Wolfgang Goethe UniversityMax-von-Laue-Strasse 760438Frankfurt/MainGermany
| | - Sabine Brantl
- AG BakteriengenetikMatthias-Schleiden-InstitutPhilosophenweg 1207743JenaGermany
| | - Elena Evguenieva‐Hackenberg
- Institute for Microbiology and Molecular BiologyJustus Liebig University GiessenHeinrich-Buff-Ring 2635392GiessenGermany
| | - Wolfgang R. Hess
- Faculty of Biology, Genetics and Experimental BioinformaticsAlbert Ludwigs University FreiburgSchänzlestrasse 179104FreiburgGermany
| | - Gabriele Klug
- Institute for Microbiology and Molecular BiologyJustus Liebig University GiessenHeinrich-Buff-Ring 2635392GiessenGermany
| | | | - Jörg Soppa
- Institute for Molecular BiosciencesJohann Wolfgang Goethe UniversityMax-von-Laue-Strasse 960438Frankfurt am MainGermany
| | - Wolfgang Streit
- Department of Microbiology and BiotechnologyUniversity of HamburgOhnhorststrasse 1822609HamburgGermany
| | - Maxim Mayzel
- Swedish NMR CentreUniversity of GothenburgP. O. Box 46540530GothenburgSweden
| | - Vladislav Y. Orekhov
- Swedish NMR CentreUniversity of GothenburgP. O. Box 46540530GothenburgSweden
- Department of Chemistry and Molecular BiologyUniversity of GothenburgKemigården 441296GothenburgSweden
| | - Monika Fuxreiter
- MTA-DE Laboratory of Protein DynamicsDepartment of Biochemistry and Molecular BiologyUniversity of DebrecenNagyerdei krt 984032DebrecenHungary
| | - Ruth A. Schmitz
- Institute for General MicrobiologyChristian Albrechts University KielAm Botanischen Garten 1–924118KielGermany
| | - Harald Schwalbe
- Institute for Organic Chemistry and Chemical BiologyCenter for Biomolecular Magnetic Resonance (BMRZ)Johann Wolfgang Goethe UniversityMax-von-Laue-Strasse 760438Frankfurt/MainGermany
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17
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Njomen E, Tepe JJ. Regulation of Autophagic Flux by the 20S Proteasome. Cell Chem Biol 2019; 26:1283-1294.e5. [PMID: 31327703 PMCID: PMC6754308 DOI: 10.1016/j.chembiol.2019.07.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 04/24/2019] [Accepted: 06/28/2019] [Indexed: 12/13/2022]
Abstract
The proteolytic arm of the protein homeostasis network is maintained by both the ubiquitin-proteasome system (UPS) and autophagy. A well-balanced crosstalk between the two catabolic pathways ensures energy-efficient maintenance of cellular function. Our current understanding of the crosstalk between the UPS and autophagy is centered around substrate ubiquitination. Herein we report an additional method of crosstalk involving ubiquitin-independent 20S proteasome regulation of autophagosome-lysosome fusion. We found that enhancement of 20S proteasome activity increased the degradation of the disordered soluble N-ethylmaleimide-sensitive factor activating protein receptor proteins, synaptosomal-associated protein 29 (SNAP29), and syntaxin 17 (STX17), but not vesicle-associated membrane protein 8. This resulted in a reduction of autophagosome-lysosome fusion, which was ameliorated upon overexpression of both SNAP29 and STX17. In all, we herein present a mechanism of crosstalk between the proteasome and autophagy pathway that is regulated by ubiquitin-independent 20S proteasome-mediated degradation of SNAP29 and STX17.
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Affiliation(s)
- Evert Njomen
- Department of Chemistry and Pharmacology & Toxicology, Michigan State University, East Lansing, MI 48824, USA
| | - Jetze J Tepe
- Department of Chemistry and Pharmacology & Toxicology, Michigan State University, East Lansing, MI 48824, USA.
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18
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Abstract
Proteasomes are multienzyme complexes that maintain protein homeostasis (proteostasis) and important cellular functions through the degradation of misfolded, redundant, and damaged proteins. It is well established that aging is associated with the accumulation of damaged and misfolded proteins. This phenomenon is paralleled by declined proteasome activity. When the accumulation of redundant proteins exceed degradation, undesirable signaling and/or aggregation occurs and are the hallmarks of neurodegenerative diseases and many cancers. Thus, increasing proteasome activity has been recognized as a new approach to delay the onset or ameliorate the symptoms of neurodegenerative and other proteotoxic disorders. Enhancement of proteasome activity has many therapeutic potentials but is still a relatively unexplored field. In this perspective, we review current approaches, genetic manipulation, posttranslational modification, and small molecule proteasome agonists used to increase proteasome activity, challenges facing the field, and applications beyond aging and neurodegenerative diseases.
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Affiliation(s)
- Evert Njomen
- Department of Chemistry, and Pharmacology & Toxicology, Michigan State University, East Lansing, Michigan 48824, United States
| | - Jetze J. Tepe
- Department of Chemistry, and Pharmacology & Toxicology, Michigan State University, East Lansing, Michigan 48824, United States
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19
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Kudriaeva AA, Belogurov AA. Proteasome: a Nanomachinery of Creative Destruction. BIOCHEMISTRY (MOSCOW) 2019; 84:S159-S192. [PMID: 31213201 DOI: 10.1134/s0006297919140104] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
In the middle of the 20th century, it was postulated that degradation of intracellular proteins is a stochastic process. More than fifty years of intense studies have finally proven that protein degradation is a very complex and tightly regulated in time and space process that plays an incredibly important role in the vast majority of metabolic pathways. Degradation of more than a half of intracellular proteins is controlled by a hierarchically aligned and evolutionarily perfect system consisting of many components, the main ones being ubiquitin ligases and proteasomes, together referred to as the ubiquitin-proteasome system (UPS). The UPS includes more than 1000 individual components, and most of them are critical for the cell functioning and survival. In addition to the well-known signaling functions of ubiquitination, such as modification of substrates for proteasomal degradation and DNA repair, polyubiquitin (polyUb) chains are involved in other important cellular processes, e.g., cell cycle regulation, immunity, protein degradation in mitochondria, and even mRNA stability. This incredible variety of ubiquitination functions is related to the ubiquitin ability to form branching chains through the ε-amino group of any of seven lysine residues in its sequence. Deubiquitination is accomplished by proteins of the deubiquitinating enzyme family. The second main component of the UPS is proteasome, a multisubunit proteinase complex that, in addition to the degradation of functionally exhausted and damaged proteins, regulates many important cellular processes through controlled degradation of substrates, for example, transcription factors and cyclins. In addition to the ubiquitin-dependent-mediated degradation, there is also ubiquitin-independent degradation, when the proteolytic signal is either an intrinsic protein sequence or shuttle molecule. Protein hydrolysis is a critically important cellular function; therefore, any abnormalities in this process lead to systemic impairments further transforming into serious diseases, such as diabetes, malignant transformation, and neurodegenerative disorders (multiple sclerosis, Alzheimer's disease, Parkinson's disease, Creutzfeldt-Jakob disease and Huntington's disease). In this review, we discuss the mechanisms that orchestrate all components of the UPS, as well as the plurality of the fine-tuning pathways of proteasomal degradation.
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Affiliation(s)
- A A Kudriaeva
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia.
| | - A A Belogurov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia. .,Lomonosov Moscow State University, Moscow, 119991, Russia
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20
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Wendler P, Enenkel C. Nuclear Transport of Yeast Proteasomes. Front Mol Biosci 2019; 6:34. [PMID: 31157235 PMCID: PMC6532418 DOI: 10.3389/fmolb.2019.00034] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2019] [Accepted: 04/26/2019] [Indexed: 11/13/2022] Open
Abstract
Proteasomes are key proteases in regulating protein homeostasis. Their holo-enzymes are composed of 40 different subunits which are arranged in a proteolytic core (CP) flanked by one to two regulatory particles (RP). Proteasomal proteolysis is essential for the degradation of proteins which control time-sensitive processes like cell cycle progression and stress response. In dividing yeast and human cells, proteasomes are primarily nuclear suggesting that proteasomal proteolysis is mainly required in the nucleus during cell proliferation. In yeast, which have a closed mitosis, proteasomes are imported into the nucleus as immature precursors via the classical import pathway. During quiescence, the reversible absence of proliferation induced by nutrient depletion or growth factor deprivation, proteasomes move from the nucleus into the cytoplasm. In the cytoplasm of quiescent yeast, proteasomes are dissociated into CP and RP and stored in membrane-less cytoplasmic foci, named proteasome storage granules (PSGs). With the resumption of growth, PSGs clear and mature proteasomes are transported into the nucleus by Blm10, a conserved 240 kDa protein and proteasome-intrinsic import receptor. How proteasomes are exported from the nucleus into the cytoplasm is unknown.
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Affiliation(s)
- Petra Wendler
- Institut für Biochemie und Biologie, Universität Potsdam, Potsdam, Germany
| | - Cordula Enenkel
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
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21
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Sharma R, Demény M, Ambrus V, Király SB, Kurtán T, Gatti-Lafranconi P, Fuxreiter M. Specific and Fuzzy Interactions Cooperate in Modulating Protein Half-Life. J Mol Biol 2019; 431:1700-1707. [PMID: 30790629 DOI: 10.1016/j.jmb.2019.02.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 01/24/2019] [Accepted: 02/03/2019] [Indexed: 11/29/2022]
Abstract
Protein degradation is critical for maintaining cellular homeostasis. The 20S proteasome is selective for unfolded, extended polypeptide chains without ubiquitin tags. Sequestration of such segments by protein partners, however, may provide a regulatory mechanism. Here we used the AP-1 complex to study how c-Fos turnover is controlled by interactions with c-Jun. We show that heterodimerization with c-Jun increases c-Fos half-life. Mutations affecting specific contact sites (L165V, L172V) or charge separation (E175D, E189D, K190R) with c-Jun both modulate c-Fos turnover, proportionally to their impact on binding affinity. The fuzzy tail beyond the structured b-HLH/ZIP domain (~165 residues) also contributes to the stabilization of the AP-1 complex, removal of which decreases c-Fos half-life. Thus, protein turnover by 20S proteasome is fine-tuned by both specific and fuzzy interactions, consistently with the previously proposed "nanny" model.
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Affiliation(s)
- Rashmi Sharma
- MTA-DE Laboratory of Protein Dynamics, Department of Biochemistry and Molecular Biology, University of Debrecen, Debrecen, Hungary
| | - Máté Demény
- MTA-DE Laboratory of Protein Dynamics, Department of Biochemistry and Molecular Biology, University of Debrecen, Debrecen, Hungary
| | - Viktor Ambrus
- MTA-DE Laboratory of Protein Dynamics, Department of Biochemistry and Molecular Biology, University of Debrecen, Debrecen, Hungary
| | | | - Tibor Kurtán
- Department of Organic Chemistry, University of Debrecen, Debrecen, Hungary
| | | | - Monika Fuxreiter
- MTA-DE Laboratory of Protein Dynamics, Department of Biochemistry and Molecular Biology, University of Debrecen, Debrecen, Hungary.
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22
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Caputi FF, Rullo L, Stamatakos S, Candeletti S, Romualdi P. Interplay between the Endogenous Opioid System and Proteasome Complex: Beyond Signaling. Int J Mol Sci 2019; 20:ijms20061441. [PMID: 30901925 PMCID: PMC6470665 DOI: 10.3390/ijms20061441] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 03/13/2019] [Accepted: 03/19/2019] [Indexed: 02/07/2023] Open
Abstract
Intracellular signaling mechanisms underlying the opioid system regulation of nociception, neurotransmitters release, stress responses, depression, and the modulation of reward circuitry have been investigated from different points of view. The presence of the ubiquitin proteasome system (UPS) in the synaptic terminations suggest a potential role of ubiquitin-dependent mechanisms in the control of the membrane occupancy by G protein-coupled receptors (GPCRs), including those belonging to the opioid family. In this review, we focused our attention on the role played by the ubiquitination processes and by UPS in the modulation of opioid receptor signaling and in pathological conditions involving the endogenous opioid system. The collective evidence here reported highlights the potential usefulness of proteasome inhibitors in neuropathic pain, addictive behavior, and analgesia since these molecules can reduce pain behavioral signs, heroin self-administration, and the development of morphine analgesic tolerance. Moreover, the complex mechanisms involved in the effects induced by opioid agonists binding to their receptors include the ubiquitination process as a post-translational modification which plays a relevant role in receptor trafficking and degradation. Hence, UPS modulation may offer novel opportunities to control the balance between therapeutic versus adverse effects evoked by opioid receptor activation, thus, representing a promising druggable target.
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Affiliation(s)
- Francesca Felicia Caputi
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum-University of Bologna, Irnerio 48, 40126 Bologna, Italy.
| | - Laura Rullo
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum-University of Bologna, Irnerio 48, 40126 Bologna, Italy.
| | - Serena Stamatakos
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum-University of Bologna, Irnerio 48, 40126 Bologna, Italy.
| | - Sanzio Candeletti
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum-University of Bologna, Irnerio 48, 40126 Bologna, Italy.
| | - Patrizia Romualdi
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum-University of Bologna, Irnerio 48, 40126 Bologna, Italy.
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23
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Martinelli AHS, Lopes FC, John EBO, Carlini CR, Ligabue-Braun R. Modulation of Disordered Proteins with a Focus on Neurodegenerative Diseases and Other Pathologies. Int J Mol Sci 2019; 20:ijms20061322. [PMID: 30875980 PMCID: PMC6471803 DOI: 10.3390/ijms20061322] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 02/03/2019] [Accepted: 02/12/2019] [Indexed: 12/15/2022] Open
Abstract
Intrinsically disordered proteins (IDPs) do not have rigid 3D structures, showing changes in their folding depending on the environment or ligands. Intrinsically disordered proteins are widely spread in eukaryotic genomes, and these proteins participate in many cell regulatory metabolism processes. Some IDPs, when aberrantly folded, can be the cause of some diseases such as Alzheimer′s, Parkinson′s, and prionic, among others. In these diseases, there are modifications in parts of the protein or in its entirety. A common conformational variation of these IDPs is misfolding and aggregation, forming, for instance, neurotoxic amyloid plaques. In this review, we discuss some IDPs that are involved in neurodegenerative diseases (such as beta amyloid, alpha synuclein, tau, and the “IDP-like” PrP), cancer (p53, c-Myc), and diabetes (amylin), focusing on the structural changes of these IDPs that are linked to such pathologies. We also present the IDP modulation mechanisms that can be explored in new strategies for drug design. Lastly, we show some candidate drugs that can be used in the future for the treatment of diseases caused by misfolded IDPs, considering that cancer therapy has more advanced research in comparison to other diseases, while also discussing recent and future developments in this area of research. Therefore, we aim to provide support to the study of IDPs and their modulation mechanisms as promising approaches to combat such severe diseases.
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Affiliation(s)
- Anne H S Martinelli
- Department of Molecular Biology and Biotechnology & Department of Biophysics, Biosciences Institute-IB, (UFRGS), Porto Alegre CEP 91501-970, RS, Brazil.
| | - Fernanda C Lopes
- Center for Biotechnology, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre CEP 91501-970, RS, Brazil.
- Graduate Program in Cell and Molecular Biology, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre CEP 91501-970, RS, Brazil.
| | - Elisa B O John
- Center for Biotechnology, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre CEP 91501-970, RS, Brazil.
- Graduate Program in Cell and Molecular Biology, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre CEP 91501-970, RS, Brazil.
| | - Célia R Carlini
- Graduate Program in Cell and Molecular Biology, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre CEP 91501-970, RS, Brazil.
- Graduate Program in Medicine and Health Sciences, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre CEP 91410-000, RS, Brazil.
- Brain Institute-InsCer, Laboratory of Neurotoxins, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre CEP 90610-000, RS, Brazil.
| | - Rodrigo Ligabue-Braun
- Department of Pharmaceutical Sciences, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Porto Alegre CEP 90050-170, RS, Brazil.
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Tang M, Harrison J, Deaton CA, Johnson GVW. Tau Clearance Mechanisms. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1184:57-68. [PMID: 32096028 DOI: 10.1007/978-981-32-9358-8_5] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Efficient quality control mechanisms are essential for a healthy, functional neuron. Recognition and degradation of misfolded, damaged, or potentially toxic proteins, is a crucial aspect of protein quality control. Tau is a protein that is highly expressed in neurons, and plays an important role in modulating a number of physiological processes. Maintaining appropriate levels of tau is key for neuronal health; hence perturbations in tau clearance mechanisms are likely significant contributors to neurodegenerative diseases such as Alzheimer's disease and frontotemporal lobar degeneration. In this chapter we will first briefly review the two primary degradative mechanisms that mediate tau clearance: the proteasome system and the autophagy-lysosome pathway. This will be followed by a discussion about what is known about the contribution of each of these pathways to tau clearance. We will also present recent findings on tau degradation through the endolysosomal system. Further, how deficits in these degradative systems may contribute to the accumulation of dysfunctional or toxic forms of tau in neurodegenerative conditions is considered.
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Guharoy M, Lazar T, Tompa P. Disordered Substrates of the 20S Proteasome Link Degradation with Phase Separation. Proteomics 2018; 18:e1800276. [PMID: 30070766 DOI: 10.1002/pmic.201800276] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2018] [Revised: 07/22/2018] [Indexed: 12/16/2022]
Abstract
The 20S proteasome is known to degrade intrinsically disordered proteins (IDPs) via an ubiquitin-independent, disorder-driven mechanism. Unless protected within protein complexes or macromolecular assemblies, certain IDPs can undergo degradation mediated directly by the 20S core particle. In this issue of Proteomics, Myers et al. utilize a proteomics approach to identify ∼500 IDP substrates of the 20S proteasome. Bioinformatics analyses of these substrates demonstrate a large fraction of highly disordered RNA-binding proteins, enriched in low-complexity, prion-like domains. A number of these proteins are also known to form phase-separated membraneless organelles in amyotrophic lateral sclerosis (ALS) and other protein neuropathies. The Myers et al. study highlights potentially interesting connections between IDP degradation and the regulatory dynamics of phase-separated intracellular assemblies. Their work should stimulate further research into the mechanistic details of how the 20S proteasome controls cellular abundances of RNA-binding proteins and thereby regulates RNA-related biological functions within both physiological and pathological phase-separated assemblies.
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Affiliation(s)
- Mainak Guharoy
- VIB-VUB Center for Structural Biology, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Tamas Lazar
- VIB-VUB Center for Structural Biology, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Peter Tompa
- VIB-VUB Center for Structural Biology, Vrije Universiteit Brussel (VUB), Brussels, Belgium.,Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
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26
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Myers N, Olender T, Savidor A, Levin Y, Reuven N, Shaul Y. The Disordered Landscape of the 20S Proteasome Substrates Reveals Tight Association with Phase Separated Granules. Proteomics 2018; 18:e1800076. [PMID: 30039638 DOI: 10.1002/pmic.201800076] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 06/28/2018] [Indexed: 12/11/2022]
Abstract
Proteasomal degradation is the main route of regulated proteostasis. The 20S proteasome is the core particle (CP) responsible for the catalytic activity of all proteasome complexes. Structural constraints mean that only unfolded, extended polypeptide chains may enter the catalytic core of the 20S proteasome. It has been previously shown that the 20S CP is active in degradation of certain intrinsically disordered proteins (IDP) lacking structural constrains. Here, a comprehensive analysis of the 20S CP substrates in vitro is conducted. It is revealed that the 20S CP substrates are highly disordered. However, not all the IDPs are 20S CP substrates. The group of the IDPs that are 20S CP substrates, termed 20S-IDPome are characterized by having significantly more protein binding partners, more posttranslational modification sites, and are highly enriched for RNA binding proteins. The vast majority of them are involved in splicing, mRNA processing, and translation. Remarkably, it is found that low complexity proteins with prion-like domain (PrLD), which interact with GR or PR di-peptide repeats, are the most preferential 20S CP substrates. The finding suggests roles of the 20S CP in gene transcription and formation of phase-separated granules.
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Affiliation(s)
- Nadav Myers
- Department of Molecular Genetics, Weizmann Institute of Science Department of Molecular Genetics, 76100, Rehovot, Israel
| | - Tsviya Olender
- Department of Molecular Genetics, Weizmann Institute of Science Department of Molecular Genetics, 76100, Rehovot, Israel
| | - Alon Savidor
- The Nancy and Stephen Grand Israel National Center for Personalized Medicine (G-INCPM), Weizmann Institute of Science, 76100, Rehovot, Israel
| | - Yishai Levin
- The Nancy and Stephen Grand Israel National Center for Personalized Medicine (G-INCPM), Weizmann Institute of Science, 76100, Rehovot, Israel
| | - Nina Reuven
- Department of Molecular Genetics, Weizmann Institute of Science Department of Molecular Genetics, 76100, Rehovot, Israel
| | - Yosef Shaul
- Department of Molecular Genetics, Weizmann Institute of Science Department of Molecular Genetics, 76100, Rehovot, Israel
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27
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Singh PK, Weber A, Häcker G. The established and the predicted roles of dynein light chain in the regulation of mitochondrial apoptosis. Cell Cycle 2018; 17:1037-1047. [PMID: 30019621 DOI: 10.1080/15384101.2018.1464851] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
The mitochondrial pathway of apoptosis is regulated by the interplay between the members of Bcl-2 family. Within this family, BH3-only proteins are the sensors of apoptotic stimuli and can trigger apoptosis either by inhibiting the anti-apoptotic Bcl-2-family proteins or by directly activating the effectors Bax and Bak. An expanding body of research suggests that a number of non-Bcl-2 proteins can also interact with Bcl-2 proteins and contribute to the decision of cell fate. Dynein light chain (LC8, DYNLL or DLC), a hub protein and a dimerizing engine has been proposed to regulate the pro-apoptotic activity of two BH3-only proteins, Bim and Bmf. Our recent work has provided insight into the mechanisms through which DLC1 (DYNLL1) modulates Bim activity. Here we discuss the present day understanding of Bim-DLC interaction and endeavor to evaluate this interaction in the light of information from studies of DLC with other binding partners.
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Affiliation(s)
- Prafull Kumar Singh
- a Institute of Medical Microbiology and Hygiene, Faculty of Medicine , Medical Center-University of Freiburg , Freiburg , Germany
| | - Arnim Weber
- a Institute of Medical Microbiology and Hygiene, Faculty of Medicine , Medical Center-University of Freiburg , Freiburg , Germany
| | - Georg Häcker
- a Institute of Medical Microbiology and Hygiene, Faculty of Medicine , Medical Center-University of Freiburg , Freiburg , Germany.,b BIOSS Centre for Biological Signalling Studies , University of Freiburg , Freiburg , Germany
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28
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Tsvetkov P, Adler J, Myers N, Biran A, Reuven N, Shaul Y. Oncogenic addiction to high 26S proteasome level. Cell Death Dis 2018; 9:773. [PMID: 29991718 PMCID: PMC6039477 DOI: 10.1038/s41419-018-0806-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 05/15/2018] [Accepted: 05/17/2018] [Indexed: 12/15/2022]
Abstract
Proteasomes are large intracellular complexes responsible for the degradation of cellular proteins. The altered protein homeostasis of cancer cells results in increased dependency on proteasome function. The cellular proteasome composition comprises the 20S catalytic complex that is frequently capped with the 19S regulatory particle in forming the 26S proteasome. Proteasome inhibitors target the catalytic barrel (20S) and thus this inhibition does not allow the deconvolution of the distinct roles of 20S versus 26S proteasomes in cancer progression. We examined the degree of dependency of cancer cells specifically to the level of the 26S proteasome complex. Oncogenic transformation of human and mouse immortalized cells with mutant Ras induced a strong posttranscriptional increase of the 26S proteasome subunits, giving rise to high 26S complex levels. Depletion of a single subunit of the 19S RP was sufficient to reduce the 26S proteasome level and lower the cellular 26S/20S ratio. Under this condition the viability of the Ras-transformed MCF10A cells was severely compromised. This observation led us to hypothesize that cancer cell survival is dependent on maximal utilization of its 26S proteasomes. We validated this possibility in a large number of cancer cell lines and found that partial reduction of the 26S proteasome level impairs viability in all cancer cells examined and was not correlated with cell doubling time or reduction efficiency. Interstingly, normal human fibroblasts are refractory to the same type of 26S proteasome reduction. The suppression of 26S proteasomes in cancer cells activated the UPR and caspase-3 and cells stained positive with Annexin V. In addition, suppression of the 26S proteasome resulted in cellular proteasome redistribution, cytoplasm shrinkage, and nuclear deformation, the hallmarks of apoptosis. The observed tumor cell-specific addiction to the 26S proteasome levels sets the stage for future strategies in exploiting this dependency in cancer therapy.
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Affiliation(s)
- Peter Tsvetkov
- Department of Molecular Genetics, Weizmann Institute of Science, 76100, Rehovot, Israel.,Broad Institute of MIT and Harvard, 415 Main St., Cambridge, MA, 02142, USA
| | - Julia Adler
- Department of Molecular Genetics, Weizmann Institute of Science, 76100, Rehovot, Israel
| | - Nadav Myers
- Department of Molecular Genetics, Weizmann Institute of Science, 76100, Rehovot, Israel
| | - Assaf Biran
- Department of Molecular Genetics, Weizmann Institute of Science, 76100, Rehovot, Israel
| | - Nina Reuven
- Department of Molecular Genetics, Weizmann Institute of Science, 76100, Rehovot, Israel
| | - Yosef Shaul
- Department of Molecular Genetics, Weizmann Institute of Science, 76100, Rehovot, Israel.
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29
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Ramachandran KV, Fu JM, Schaffer TB, Na CH, Delannoy M, Margolis SS. Activity-Dependent Degradation of the Nascentome by the Neuronal Membrane Proteasome. Mol Cell 2018; 71:169-177.e6. [PMID: 29979964 PMCID: PMC6070390 DOI: 10.1016/j.molcel.2018.06.013] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 04/12/2018] [Accepted: 06/06/2018] [Indexed: 12/28/2022]
Abstract
Activity-dependent changes in neuronal function require coordinated regulation of the protein synthesis and protein degradation machinery to maintain protein homeostasis, critical for proper neuronal function. However, the biochemical evidence for this balance and coordination is largely lacking. Leveraging our recent discovery of a neuronal-specific 20S membrane proteasome complex (NMP), we began exploring how neuronal activity regulates its function. Here, we found that the NMP degrades exclusively a large fraction of ribosome-associated nascent polypeptides that are being newly synthesized during neuronal stimulation. Using deep-coverage and global mass spectrometry, we identified the nascent protein substrates of the NMP, which included products encoding immediate-early genes, such as c-Fos and Npas4. Intriguingly, we found that turnover of nascent polypeptides and not full-length proteins through the NMP occurred independent of canonical ubiquitylation pathways. We propose that these findings generally define a neuronal activity-induced protein homeostasis program of coordinated protein synthesis and degradation through the NMP.
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Affiliation(s)
- Kapil V Ramachandran
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| | - Jack M Fu
- Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Thomas B Schaffer
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Chan Hyun Na
- Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Michael Delannoy
- The Johns Hopkins University School of Medicine Microscope Facility, Baltimore, MD 21205, USA
| | - Seth S Margolis
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Solomon H. Snyder Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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30
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Abstract
Prion-like proteins overlap with intrinsically disordered and low-complexity sequence families. These proteins are widespread, especially among mRNA-binding proteins. A salient feature of these proteins is the ability to form protein assemblies with distinct biophysical and functional properties. While prion-like proteins are involved in myriad of cellular processes, we propose potential roles for protein assemblies in regulated protein synthesis. Since proteins are the ultimate functional output of gene expression, when, where, and how much of a particular protein is made dictates the functional state of a cell. Recent finding suggests that the prion-like proteins offer unique advantages in translation regulation and also raises questions regarding formation and regulation of protein assemblies.
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Affiliation(s)
- Liying Li
- Stowers Institute for Medical Research, 1000E 50(th) Street, Kansas City, MO 64110, USA; Department of Molecular and Integrative Physiology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, Kansas 66160, USA
| | - J P McGinnis
- Stowers Institute for Medical Research, 1000E 50(th) Street, Kansas City, MO 64110, USA; Department of Molecular and Integrative Physiology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, Kansas 66160, USA
| | - Kausik Si
- Stowers Institute for Medical Research, 1000E 50(th) Street, Kansas City, MO 64110, USA; Department of Molecular and Integrative Physiology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, Kansas 66160, USA.
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31
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Co-translational control of protein complex formation: a fundamental pathway of cellular organization? Biochem Soc Trans 2018; 46:197-206. [PMID: 29432142 DOI: 10.1042/bst20170451] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 12/10/2017] [Accepted: 01/08/2018] [Indexed: 12/16/2022]
Abstract
Analyses of proteomes from a large number of organisms throughout the domains of life highlight the key role played by multiprotein complexes for the implementation of cellular function. While the occurrence of multiprotein assemblies is ubiquitous, the understanding of pathways that dictate the formation of quaternary structure remains enigmatic. Interestingly, there are now well-established examples of protein complexes that are assembled co-translationally in both prokaryotes and eukaryotes, and indications are that the phenomenon is widespread in cells. Here, we review complex assembly with an emphasis on co-translational pathways, which involve interactions of nascent chains with other nascent or mature partner proteins, respectively. In prokaryotes, such interactions are promoted by the polycistronic arrangement of mRNA and the associated co-translation of functionally related cell constituents in order to enhance otherwise diffusion-dependent processes. Beyond merely stochastic events, however, co-translational complex formation may be sensitive to subunit availability and allow for overall regulation of the assembly process. We speculate how co-translational pathways may constitute integral components of quality control systems to ensure the correct and complete formation of hundreds of heterogeneous assemblies in a single cell. Coupling of folding of intrinsically disordered domains with co-translational interaction of binding partners may furthermore enhance the efficiency and fidelity with which correct conformation is attained. Co-translational complex formation may constitute a fundamental pathway of cellular organization, with profound importance for health and disease.
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32
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Functional Analysis of Human Hub Proteins and Their Interactors Involved in the Intrinsic Disorder-Enriched Interactions. Int J Mol Sci 2017; 18:ijms18122761. [PMID: 29257115 PMCID: PMC5751360 DOI: 10.3390/ijms18122761] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 12/13/2017] [Accepted: 12/15/2017] [Indexed: 12/15/2022] Open
Abstract
Some of the intrinsically disordered proteins and protein regions are promiscuous interactors that are involved in one-to-many and many-to-one binding. Several studies have analyzed enrichment of intrinsic disorder among the promiscuous hub proteins. We extended these works by providing a detailed functional characterization of the disorder-enriched hub protein-protein interactions (PPIs), including both hubs and their interactors, and by analyzing their enrichment among disease-associated proteins. We focused on the human interactome, given its high degree of completeness and relevance to the analysis of the disease-linked proteins. We quantified and investigated numerous functional and structural characteristics of the disorder-enriched hub PPIs, including protein binding, structural stability, evolutionary conservation, several categories of functional sites, and presence of over twenty types of posttranslational modifications (PTMs). We showed that the disorder-enriched hub PPIs have a significantly enlarged number of disordered protein binding regions and long intrinsically disordered regions. They also include high numbers of targeting, catalytic, and many types of PTM sites. We empirically demonstrated that these hub PPIs are significantly enriched among 11 out of 18 considered classes of human diseases that are associated with at least 100 human proteins. Finally, we also illustrated how over a dozen specific human hubs utilize intrinsic disorder for their promiscuous PPIs.
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33
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Uversky VN. The roles of intrinsic disorder-based liquid-liquid phase transitions in the "Dr. Jekyll-Mr. Hyde" behavior of proteins involved in amyotrophic lateral sclerosis and frontotemporal lobar degeneration. Autophagy 2017; 13:2115-2162. [PMID: 28980860 DOI: 10.1080/15548627.2017.1384889] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Pathological developments leading to amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD) are associated with misbehavior of several key proteins, such as SOD1 (superoxide dismutase 1), TARDBP/TDP-43, FUS, C9orf72, and dipeptide repeat proteins generated as a result of the translation of the intronic hexanucleotide expansions in the C9orf72 gene, PFN1 (profilin 1), GLE1 (GLE1, RNA export mediator), PURA (purine rich element binding protein A), FLCN (folliculin), RBM45 (RNA binding motif protein 45), SS18L1/CREST, HNRNPA1 (heterogeneous nuclear ribonucleoprotein A1), HNRNPA2B1 (heterogeneous nuclear ribonucleoprotein A2/B1), ATXN2 (ataxin 2), MAPT (microtubule associated protein tau), and TIA1 (TIA1 cytotoxic granule associated RNA binding protein). Although these proteins are structurally and functionally different and have rather different pathological functions, they all possess some levels of intrinsic disorder and are either directly engaged in or are at least related to the physiological liquid-liquid phase transitions (LLPTs) leading to the formation of various proteinaceous membrane-less organelles (PMLOs), both normal and pathological. This review describes the normal and pathological functions of these ALS- and FTLD-related proteins, describes their major structural properties, glances at their intrinsic disorder status, and analyzes the involvement of these proteins in the formation of normal and pathological PMLOs, with the ultimate goal of better understanding the roles of LLPTs and intrinsic disorder in the "Dr. Jekyll-Mr. Hyde" behavior of those proteins.
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Affiliation(s)
- Vladimir N Uversky
- a Department of Molecular Medicine and USF Health Byrd Alzheimer's Research Institute , Morsani College of Medicine , University of South Florida , Tampa , FL , USA.,b Institute for Biological Instrumentation of the Russian Academy of Sciences , Pushchino, Moscow region , Russia
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34
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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: 61] [Impact Index Per Article: 8.7] [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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35
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Uversky VN. Intrinsic Disorder, Protein-Protein Interactions, and Disease. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2017; 110:85-121. [PMID: 29413001 DOI: 10.1016/bs.apcsb.2017.06.005] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
It is recognized now that biologically active proteins without stable tertiary structure (known as intrinsically disordered proteins, IDPs) and hybrid proteins containing ordered domains and intrinsically disordered protein regions (IDPRs) are important players found in any given proteome. These IDPs/IDPRs possess functions that complement functional repertoire of their ordered counterparts, being commonly related to recognition, as well as control and regulation of various signaling pathways. They are interaction masters, being able to utilize a wide spectrum of interaction mechanisms, ranging from induced folding to formation of fuzzy complexes where significant levels of disorder are preserved, to polyvalent stochastic interactions playing crucial roles in the liquid-liquid phase transitions leading to the formation of proteinaceous membrane-less organelles. IDPs/IDPRs are tightly controlled themselves via various means, including alternative splicing, precisely controlled expression and degradation, binding to specific partners, and posttranslational modifications. Distortions in the regulation and control of IDPs/IDPRs, as well as their aberrant interactivity are commonly associated with various human diseases. This review presents some aspects of the intrinsic disorder-based functionality and dysfunctionality, paying special attention to the normal and pathological protein-protein interactions.
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Affiliation(s)
- Vladimir N Uversky
- USF Health Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL, United States; Institute for Biological Instrumentation, Russian Academy of Sciences, Pushchino, Moscow Region, Russia.
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36
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Yedidi RS, Wendler P, Enenkel C. AAA-ATPases in Protein Degradation. Front Mol Biosci 2017; 4:42. [PMID: 28676851 PMCID: PMC5476697 DOI: 10.3389/fmolb.2017.00042] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2017] [Accepted: 06/06/2017] [Indexed: 11/13/2022] Open
Abstract
Proteolytic machineries containing multisubunit protease complexes and AAA-ATPases play a key role in protein quality control and the regulation of protein homeostasis. In these protein degradation machineries, the proteolytically active sites are formed by either threonines or serines which are buried inside interior cavities of cylinder-shaped complexes. In eukaryotic cells, the proteasome is the most prominent protease complex harboring AAA-ATPases. To degrade protein substrates, the gates of the axial entry ports of the protease need to be open. Gate opening is accomplished by AAA-ATPases, which form a hexameric ring flanking the entry ports of the protease. Protein substrates with unstructured domains can loop into the entry ports without the assistance of AAA-ATPases. However, folded proteins require the action of AAA-ATPases to unveil an unstructured terminus or domain. Cycles of ATP binding/hydrolysis fuel the unfolding of protein substrates which are gripped by loops lining up the central pore of the AAA-ATPase ring. The AAA-ATPases pull on the unfolded polypeptide chain for translocation into the proteolytic cavity of the protease. Conformational changes within the AAA-ATPase ring and the adjacent protease chamber create a peristaltic movement for substrate degradation. The review focuses on new technologies toward the understanding of the function and structure of AAA-ATPases to achieve substrate recognition, unfolding and translocation into proteasomes in yeast and mammalian cells and into proteasome-equivalent proteases in bacteria and archaea.
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Affiliation(s)
| | - Petra Wendler
- Department of Biochemistry, Institute of Biochemistry and Biology, University of PotsdamPotsdam, Germany
| | - Cordula Enenkel
- Department of Biochemistry, University of TorontoToronto, ON, Canada
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37
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Hurley JM, Loros JJ, Dunlap JC. Circadian Oscillators: Around the Transcription-Translation Feedback Loop and on to Output. Trends Biochem Sci 2016; 41:834-846. [PMID: 27498225 DOI: 10.1016/j.tibs.2016.07.009] [Citation(s) in RCA: 128] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Revised: 07/10/2016] [Accepted: 07/14/2016] [Indexed: 12/20/2022]
Abstract
From cyanobacteria to mammals, organisms have evolved timing mechanisms to adapt to environmental changes in order to optimize survival and improve fitness. To anticipate these regular daily cycles, many organisms manifest ∼24h cell-autonomous oscillations that are sustained by transcription-translation-based or post-transcriptional negative-feedback loops that control a wide range of biological processes. With an eye to identifying emerging common themes among cyanobacterial, fungal, and animal clocks, some major recent developments in the understanding of the mechanisms that regulate these oscillators and their output are discussed. These include roles for antisense transcription, intrinsically disordered proteins, codon bias in clock genes, and a more focused discussion of post-transcriptional and translational regulation as a part of both the oscillator and output.
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Affiliation(s)
- Jennifer M Hurley
- Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, NY 12180, USA.
| | - Jennifer J Loros
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA
| | - Jay C Dunlap
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA.
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38
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The yeast Hsp70 homolog Ssb: a chaperone for general de novo protein folding and a nanny for specific intrinsically disordered protein domains. Curr Genet 2016; 63:9-13. [PMID: 27230907 PMCID: PMC5274638 DOI: 10.1007/s00294-016-0610-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 05/06/2016] [Accepted: 05/09/2016] [Indexed: 12/17/2022]
Abstract
Activation of the heterotrimeric kinase SNF1 via phosphorylation of a specific residue within the α subunit is essential for the release from glucose repression in the yeast Saccharomyces cerevisiae. When glucose is available, SNF1 is maintained in the dephosphorylated, inactive state by the phosphatase Glc7-Reg1. Recent findings suggest that Bmh and Ssb combine their unique client-binding properties to interact with the regulatory region of the SNF1 α subunit and by that stabilize a conformation of SNF1, which is accessible for Glc7-Reg1-dependent dephosphorylation. Together, the 14-3-3 protein Bmh and the Hsp70 homolog Ssb comprise a novel chaperone module, which is required to maintain proper glucose repression in the yeast S. cerevisiae.
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Caputi FF, Carboni L, Mazza D, Candeletti S, Romualdi P. Cocaine and ethanol target 26S proteasome activity and gene expression in neuroblastoma cells. Drug Alcohol Depend 2016; 161:265-75. [PMID: 26922280 DOI: 10.1016/j.drugalcdep.2016.02.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 01/26/2016] [Accepted: 02/05/2016] [Indexed: 10/22/2022]
Abstract
BACKGROUND Ethanol and cocaine are widely abused drugs triggering long-lasting changes in neuronal circuits and synaptic transmission through the regulation of enzyme activity and gene expression. Compelling evidence indicates that the ubiquitin-proteasome system plays a role in the molecular changes induced by addictive substances, impacting on several mechanisms implicated in abuse. The goal of these studies was to evaluate the effects of cocaine or ethanol on proteasome activity in neuroblastoma cells. Moreover, the gene expression of specific subunits was assessed. METHODS Chymotrypsin-like activity was measured after 2 h, 24 h, and 48 h exposure to 5 μM cocaine or 40 mM ethanol. Proteasome subunit transcripts were evaluated by qPCR at the same time-points. RESULTS Treatments modified proteasome function in opposite directions, since cocaine increased and ethanol reduced chymotrypsin-like activity. Interestingly, we observed gene expression alterations induced by these drugs. In the core particle, the β1 and α5 subunits were mainly up-regulated by cocaine, whereas α6 transcripts were mostly decreased. β2 and β5 did not change. Similarly, ethanol exposure generally increased β1 and α5 mRNAs. Moreover, the β2 subunit was significantly up-regulated by ethanol only. The β5 and α6 subunits were not altered. In the regulatory particle, Rpt3 was increased by cocaine exposure, whereas it was reduced by ethanol. No significant Rpn9 alterations were observed. CONCLUSIONS These findings support the notion that addictive substances regulate proteasome function, contributing to the dysregulations related to drug abuse since the availability of adequate subunit amounts is necessary for proper complex assembly and function.
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Affiliation(s)
- Francesca Felicia Caputi
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum-University of Bologna, Irnerio 48, 40126 Bologna, Italy.
| | - Lucia Carboni
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum-University of Bologna, Irnerio 48, 40126 Bologna, Italy
| | - Daria Mazza
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum-University of Bologna, Irnerio 48, 40126 Bologna, Italy
| | - Sanzio Candeletti
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum-University of Bologna, Irnerio 48, 40126 Bologna, Italy
| | - Patrizia Romualdi
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum-University of Bologna, Irnerio 48, 40126 Bologna, Italy
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40
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Emerging Roles of Disordered Sequences in RNA-Binding Proteins. Trends Biochem Sci 2015; 40:662-672. [DOI: 10.1016/j.tibs.2015.08.012] [Citation(s) in RCA: 161] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Revised: 08/21/2015] [Accepted: 08/31/2015] [Indexed: 12/12/2022]
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Tsvetkov P, Mendillo ML, Zhao J, Carette JE, Merrill PH, Cikes D, Varadarajan M, van Diemen FR, Penninger JM, Goldberg AL, Brummelkamp TR, Santagata S, Lindquist S. Compromising the 19S proteasome complex protects cells from reduced flux through the proteasome. eLife 2015; 4. [PMID: 26327695 PMCID: PMC4551903 DOI: 10.7554/elife.08467] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Accepted: 07/29/2015] [Indexed: 12/11/2022] Open
Abstract
Proteasomes are central regulators of protein homeostasis in eukaryotes. Proteasome function is vulnerable to environmental insults, cellular protein imbalance and targeted pharmaceuticals. Yet, mechanisms that cells deploy to counteract inhibition of this central regulator are little understood. To find such mechanisms, we reduced flux through the proteasome to the point of toxicity with specific inhibitors and performed genome-wide screens for mutations that allowed cells to survive. Counter to expectation, reducing expression of individual subunits of the proteasome's 19S regulatory complex increased survival. Strong 19S reduction was cytotoxic but modest reduction protected cells from inhibitors. Protection was accompanied by an increased ratio of 20S to 26S proteasomes, preservation of protein degradation capacity and reduced proteotoxic stress. While compromise of 19S function can have a fitness cost under basal conditions, it provided a powerful survival advantage when proteasome function was impaired. This means of rebalancing proteostasis is conserved from yeast to humans.
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Affiliation(s)
- Peter Tsvetkov
- Whitehead Institute for Biomedical Research, Cambridge, United States
| | - Marc L Mendillo
- Department of Biology, Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, United States
| | - Jinghui Zhao
- Department of Cell Biology, Harvard Medical School, Boston, United States
| | - Jan E Carette
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, United States
| | - Parker H Merrill
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, United States
| | - Domagoj Cikes
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria
| | | | - Ferdy R van Diemen
- Department of Biochemistry, Netherlands Cancer Institute, Amsterdam, Netherlands
| | - Josef M Penninger
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria
| | - Alfred L Goldberg
- Department of Cell Biology, Harvard Medical School, Boston, United States
| | - Thijn R Brummelkamp
- Department of Biochemistry, Netherlands Cancer Institute, Amsterdam, Netherlands
| | - Sandro Santagata
- Whitehead Institute for Biomedical Research, Cambridge, United States
| | - Susan Lindquist
- Whitehead Institute for Biomedical Research, Cambridge, United States
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42
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Fuzzy complexes: Specific binding without complete folding. FEBS Lett 2015; 589:2533-42. [PMID: 26226339 DOI: 10.1016/j.febslet.2015.07.022] [Citation(s) in RCA: 158] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 07/20/2015] [Accepted: 07/21/2015] [Indexed: 12/17/2022]
Abstract
Specific molecular recognition is assumed to require a well-defined set of contacts and devoid of conformational and interaction ambiguities. Growing experimental evidence demonstrates however, that structural multiplicity or dynamic disorder can be retained in protein complexes, termed as fuzziness. Fuzzy regions establish alternative contacts between specific partners usually via transient interactions. Nature often tailors the dynamic properties of these segments via post-translational modifications or alternative splicing to fine-tune affinity. Most experimentally characterized fuzzy complexes are involved in regulation of gene-expression, signal transduction and cell-cycle regulation. Fuzziness is also characteristic to viral protein complexes, cytoskeleton structure, and surprisingly in a few metabolic enzymes. A plausible role of fuzzy complexes in increasing half-life of intrinsically disordered proteins is also discussed.
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Montenegro-Montero A, Canessa P, Larrondo LF. Around the Fungal Clock. ADVANCES IN GENETICS 2015; 92:107-84. [DOI: 10.1016/bs.adgen.2015.09.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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44
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Gitlin L, Hagai T, LaBarbera A, Solovey M, Andino R. Rapid evolution of virus sequences in intrinsically disordered protein regions. PLoS Pathog 2014; 10:e1004529. [PMID: 25502394 PMCID: PMC4263755 DOI: 10.1371/journal.ppat.1004529] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 10/20/2014] [Indexed: 11/18/2022] Open
Abstract
Nodamura Virus (NoV) is a nodavirus originally isolated from insects that can replicate in a wide variety of hosts, including mammals. Because of their simplicity and ability to replicate in many diverse hosts, NoV, and the Nodaviridae in general, provide a unique window into the evolution of viruses and host-virus interactions. Here we show that the C-terminus of the viral polymerase exhibits extreme structural and evolutionary flexibility. Indeed, fewer than 10 positively charged residues from the 110 amino acid-long C-terminal region of protein A are required to support RNA1 replication. Strikingly, this region can be replaced by completely unrelated protein sequences, yet still produce a functional replicase. Structure predictions, as well as evolutionary and mutational analyses, indicate that the C-terminal region is structurally disordered and evolves faster than the rest of the viral proteome. Thus, the function of an intrinsically unstructured protein region can be independent of most of its primary sequence, conferring both functional robustness and sequence plasticity on the protein. Our results provide an experimental explanation for rapid evolution of unstructured regions, which enables an effective exploration of the sequence space, and likely function space, available to the virus. Proteins often contain regions with defined structures that enable their function. While important for maintaining the overall architecture of the protein, structural conservation adds constraints on the ability of the protein to mutate, and thus evolve. Viruses of eukaryotes, however, often encode for proteins with unstructured regions. As these regions are less constrained, they are more likely to accumulate mutations, which in turn can facilitate the appearance of novel functions during the evolution of the virus. Even though it has been known that such “disordered protein regions” have been particularly malleable in evolution, their functions and their ability to withstand extensive mutations have not been explored in detail. Here, we discovered that a disordered part of the Nodamura Virus polymerase is both required for replication of the viral genome, and extremely variable among different nodaviruses. We examined the tolerance of this protein region to mutations and found an unexpected ability to accommodate very diverse protein sequences. We propose that disordered protein regions can be a reservoir for evolutionary innovation that can play important roles in virus adaptation to new environments.
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Affiliation(s)
- Leonid Gitlin
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, California, United States of America
| | - Tzachi Hagai
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, California, United States of America
| | - Anthony LaBarbera
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, California, United States of America
| | - Mark Solovey
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, California, United States of America
| | - Raul Andino
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, California, United States of America
- * E-mail:
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45
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George-Raizen JB, Shockley KR, Trojanowski NF, Lamb AL, Raizen DM. Dynamically-expressed prion-like proteins form a cuticle in the pharynx of Caenorhabditis elegans. Biol Open 2014; 3:1139-49. [PMID: 25361578 PMCID: PMC4232772 DOI: 10.1242/bio.20147500] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
In molting animals, a cuticular extracellular matrix forms the first barrier to infection and other environmental insults. In the nematode Caenorhabditis elegans there are two types of cuticle: a well-studied collagenous cuticle lines the body, and a poorly-understood chitinous cuticle lines the pharynx. In the posterior end of the pharynx is the grinder, a tooth-like cuticular specialization that crushes food prior to transport to the intestine for digestion. We here show that the grinder increases in size only during the molt. To gain molecular insight into the structure of the grinder and pharyngeal cuticle, we performed a microarray analysis to identify mRNAs increased during the molt. We found strong transcriptional induction during the molt of 12 of 15 previously identified abu genes encoding Prion-like (P) glutamine (Q) and asparagine (N) rich PQN proteins, as well as 15 additional genes encoding closely related PQN proteins. abu/pqn genes, which we name the abu/pqn paralog group (APPG) genes, were expressed in pharyngeal cells and the proteins encoded by two APPG genes we tested localized to the pharyngeal cuticle. Deleting the APPG gene abu-14 caused abnormal pharyngeal cuticular structures and knocking down other APPG genes resulted in abnormal cuticular function. We propose that APPG proteins promote the assembly and function of a unique cuticular structure. The strong developmental regulation of the APPG genes raises the possibility that such genes would be identified in transcriptional profiling experiments in which the animals' developmental stage is not precisely staged.
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Affiliation(s)
- Julia B George-Raizen
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Keith R Shockley
- Biostatistics Branch, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC 27709, USA
| | - Nicholas F Trojanowski
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Annesia L Lamb
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA Present address: Department of Earth and Environmental Sciences, The Graduate Center, The City University of New York, 365 Fifth Avenue, New York, NY 10016, USA
| | - David M Raizen
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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van der Lee R, Lang B, Kruse K, Gsponer J, Sánchez de Groot N, Huynen MA, Matouschek A, Fuxreiter M, Babu MM. Intrinsically disordered segments affect protein half-life in the cell and during evolution. Cell Rep 2014; 8:1832-1844. [PMID: 25220455 PMCID: PMC4358326 DOI: 10.1016/j.celrep.2014.07.055] [Citation(s) in RCA: 167] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Revised: 06/12/2014] [Accepted: 07/29/2014] [Indexed: 01/09/2023] Open
Abstract
Precise control of protein turnover is essential for cellular homeostasis. The ubiquitin-proteasome system is well established as a major regulator of protein degradation, but an understanding of how inherent structural features influence the lifetimes of proteins is lacking. We report that yeast, mouse, and human proteins with terminal or internal intrinsically disordered segments have significantly shorter half-lives than proteins without these features. The lengths of the disordered segments that affect protein half-life are compatible with the structure of the proteasome. Divergence in terminal and internal disordered segments in yeast proteins originating from gene duplication leads to significantly altered half-life. Many paralogs that are affected by such changes participate in signaling, where altered protein half-life will directly impact cellular processes and function. Thus, natural variation in the length and position of disordered segments may affect protein half-life and could serve as an underappreciated source of genetic variation with important phenotypic consequences.
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Affiliation(s)
- Robin van der Lee
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK; Centre for Molecular and Biomolecular Informatics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Centre, 6500 HB Nijmegen, the Netherlands.
| | - Benjamin Lang
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Kai Kruse
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Jörg Gsponer
- Centre for High-Throughput Biology, University of British Columbia, East Mall, Vancouver BC V6T 1Z4, Canada
| | | | - Martijn A Huynen
- Centre for Molecular and Biomolecular Informatics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Centre, 6500 HB Nijmegen, the Netherlands
| | - Andreas Matouschek
- Department of Molecular Biosciences and Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, TX 78712, USA
| | - Monika Fuxreiter
- MTA-DE Momentum Laboratory of Protein Dynamics, Department of Biochemistry and Molecular Biology, University of Debrecen, Debrecen 4032, Hungary
| | - M Madan Babu
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK.
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47
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Ben-Nissan G, Sharon M. Regulating the 20S proteasome ubiquitin-independent degradation pathway. Biomolecules 2014; 4:862-84. [PMID: 25250704 PMCID: PMC4192676 DOI: 10.3390/biom4030862] [Citation(s) in RCA: 242] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2014] [Revised: 08/27/2014] [Accepted: 09/05/2014] [Indexed: 02/07/2023] Open
Abstract
For many years, the ubiquitin-26S proteasome degradation pathway was considered the primary route for proteasomal degradation. However, it is now becoming clear that proteins can also be targeted for degradation by the core 20S proteasome itself. Degradation by the 20S proteasome does not require ubiquitin tagging or the presence of the 19S regulatory particle; rather, it relies on the inherent structural disorder of the protein being degraded. Thus, proteins that contain unstructured regions due to oxidation, mutation, or aging, as well as naturally, intrinsically unfolded proteins, are susceptible to 20S degradation. Unlike the extensive knowledge acquired over the years concerning degradation by the 26S proteasome, relatively little is known about the means by which 20S-mediated proteolysis is controlled. Here, we describe our current understanding of the regulatory mechanisms that coordinate 20S proteasome-mediated degradation, and highlight the gaps in knowledge that remain to be bridged.
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Affiliation(s)
- Gili Ben-Nissan
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot 7610001, Israel.
| | - Michal Sharon
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot 7610001, Israel.
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48
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Glatiramer acetate and nanny proteins restrict access of the multiple sclerosis autoantigen myelin basic protein to the 26S proteasome. BIOMED RESEARCH INTERNATIONAL 2014; 2014:926394. [PMID: 25276831 PMCID: PMC4172982 DOI: 10.1155/2014/926394] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Revised: 08/13/2014] [Accepted: 08/16/2014] [Indexed: 12/23/2022]
Abstract
We recently showed that myelin basic protein (MBP) is hydrolyzed by 26S proteasome without ubiquitination. The previously suggested concept of charge-mediated interaction between MBP and the proteasome led us to attempt to compensate or mimic its positive charge to inhibit proteasomal degradation. We demonstrated that negatively charged actin and calmodulin (CaM), as well as basic histone H1.3, inhibit MBP hydrolysis by competing with the proteasome and MBP, respectively, for binding their counterpart. Interestingly, glatiramer acetate (GA), which is used to treat multiple sclerosis (MS) and is structurally similar to MBP, inhibits intracellular and in vitro proteasome-mediated MBP degradation. Therefore, the data reported in this study may be important for myelin biogenesis in both the normal state and pathophysiological conditions.
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49
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Uversky VN. Wrecked regulation of intrinsically disordered proteins in diseases: pathogenicity of deregulated regulators. Front Mol Biosci 2014; 1:6. [PMID: 25988147 PMCID: PMC4428494 DOI: 10.3389/fmolb.2014.00006] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Accepted: 07/06/2014] [Indexed: 12/14/2022] Open
Abstract
Biologically active proteins without stable tertiary structure are common in all known proteomes. Functions of these intrinsically disordered proteins (IDPs) are typically related to regulation, signaling, and control. Cellular levels of these important regulators are tightly regulated by a variety mechanisms ranging from firmly controlled expression to precisely targeted degradation. Functions of IDPs are controlled by binding to specific partners, alternative splicing, and posttranslational modifications among other means. In the norm, right amounts of precisely activated IDPs have to be present in right time at right places. Wrecked regulation brings havoc to the ordered world of disordered proteins, leading to protein misfolding, misidentification, and missignaling that give rise to numerous human diseases, such as cancer, cardiovascular disease, neurodegenerative diseases, and diabetes. Among factors inducing pathogenic transformations of IDPs are various cellular mechanisms, such as chromosomal translocations, damaged splicing, altered expression, frustrated posttranslational modifications, aberrant proteolytic degradation, and defective trafficking. This review presents some of the aspects of deregulated regulation of IDPs leading to human diseases.
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Affiliation(s)
- Vladimir N Uversky
- Department of Molecular Medicine and USF Health Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida Tampa, FL, USA ; Biology Department, Faculty of Science, King Abdulaziz University Jeddah, Saudi Arabia ; Laboratory of New Methods in Biology, Institute for Biological Instrumentation, Russian Academy of Sciences Moscow, Russia
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50
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Modelling the structure of full-length Epstein–Barr virus nuclear antigen 1. Virus Genes 2014; 49:358-72. [DOI: 10.1007/s11262-014-1101-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Accepted: 06/27/2014] [Indexed: 12/27/2022]
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