1
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Cóppola-Segovia V, Reggiori F. Molecular Insights into Aggrephagy: Their Cellular Functions in the Context of Neurodegenerative Diseases. J Mol Biol 2024; 436:168493. [PMID: 38360089 DOI: 10.1016/j.jmb.2024.168493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 02/06/2024] [Accepted: 02/09/2024] [Indexed: 02/17/2024]
Abstract
Protein homeostasis or proteostasis is an equilibrium of biosynthetic production, folding and transport of proteins, and their timely and efficient degradation. Proteostasis is guaranteed by a network of protein quality control systems aimed at maintaining the proteome function and avoiding accumulation of potentially cytotoxic proteins. Terminal unfolded and dysfunctional proteins can be directly turned over by the ubiquitin-proteasome system (UPS) or first amassed into aggregates prior to degradation. Aggregates can also be disposed into lysosomes by a selective type of autophagy known as aggrephagy, which relies on a set of so-called selective autophagy receptors (SARs) and adaptor proteins. Failure in eliminating aggregates, also due to defects in aggrephagy, can have devastating effects as underscored by several neurodegenerative diseases or proteinopathies, which are characterized by the accumulation of aggregates mostly formed by a specific disease-associated, aggregate-prone protein depending on the clinical pathology. Despite its medical relevance, however, the process of aggrephagy is far from being understood. Here we review the findings that have helped in assigning a possible function to specific SARs and adaptor proteins in aggrephagy in the context of proteinopathies, and also highlight the interplay between aggrephagy and the pathogenesis of proteinopathies.
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Affiliation(s)
| | - Fulvio Reggiori
- Department of Biomedicine, Aarhus University, Ole Worms Allé 4, 8000 Aarhus C, Denmark; Aarhus Institute of Advanced Studies (AIAS), Aarhus University, Høegh-Guldbergs Gade 6B, 8000 Aarhus C, Denmark.
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2
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Strohm L, Hu Z, Suk Y, Rühmkorf A, Sternburg E, Gattringer V, Riemenschneider H, Berutti R, Graf E, Weishaupt JH, Brill MS, Harbauer AB, Dormann D, Dengjel J, Edbauer D, Behrends C. Multi-omics profiling identifies a deregulated FUS-MAP1B axis in ALS/FTD-associated UBQLN2 mutants. Life Sci Alliance 2022; 5:5/11/e202101327. [PMID: 35777956 PMCID: PMC9258132 DOI: 10.26508/lsa.202101327] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 06/10/2022] [Accepted: 06/14/2022] [Indexed: 11/24/2022] Open
Abstract
Analysis of ALS patient-derived and engineered cells revealed that mutant UBQLN2 increases mRNA and protein of MAP1B which is mediated by dephosphorylation of FUS within its RNA-binding domain. Ubiquilin-2 (UBQLN2) is a ubiquitin-binding protein that shuttles ubiquitinated proteins to proteasomal and autophagic degradation. UBQLN2 mutations are genetically linked to the neurodegenerative disorders amyotrophic lateral sclerosis and frontotemporal dementia (ALS/FTD). However, it remains elusive how UBQLN2 mutations cause ALS/FTD. Here, we systematically examined proteomic and transcriptomic changes in patient-derived lymphoblasts and CRISPR/Cas9–engineered HeLa cells carrying ALS/FTD UBQLN2 mutations. This analysis revealed a strong up-regulation of the microtubule-associated protein 1B (MAP1B) which was also observed in UBQLN2 knockout cells and primary rodent neurons depleted of UBQLN2, suggesting that a UBQLN2 loss-of-function mechanism is responsible for the elevated MAP1B levels. Consistent with MAP1B’s role in microtubule binding, we detected an increase in total and acetylated tubulin. Furthermore, we uncovered that UBQLN2 mutations result in decreased phosphorylation of MAP1B and of the ALS/FTD–linked fused in sarcoma (FUS) protein at S439 which is critical for regulating FUS-RNA binding and MAP1B protein abundance. Together, our findings point to a deregulated UBQLN2-FUS-MAP1B axis that may link protein homeostasis, RNA metabolism, and cytoskeleton dynamics, three molecular pathomechanisms of ALS/FTD.
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Affiliation(s)
- Laura Strohm
- Munich Cluster for Systems Neurology, Medical Faculty, Ludwig-Maximilians-University München, Munich, Germany
| | - Zehan Hu
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Yongwon Suk
- Institute for Molecular Physiology, Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Alina Rühmkorf
- Max Planck Institute of Neurobiology, Martinsried, Germany
| | - Erin Sternburg
- Institute for Molecular Physiology, Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Vanessa Gattringer
- Munich Cluster for Systems Neurology, Medical Faculty, Ludwig-Maximilians-University München, Munich, Germany
| | - Henrick Riemenschneider
- Munich Cluster for Systems Neurology, Medical Faculty, Ludwig-Maximilians-University München, Munich, Germany.,German Center for Neurodegenerative Diseases Munich, Munich, Germany
| | - Riccardo Berutti
- Institute of Human Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Elisabeth Graf
- Institut für Humangenetik, Klinikum Rechts der Isar der Technischen Universität München, Munich, Germany
| | - Jochen H Weishaupt
- Division of Neurodegenerative Disorders, Department of Neurology, Medical Faculty Mannheim, Mannheim Center for Translational Neurosciences, Heidelberg University, Mannheim, Germany
| | | | - Angelika B Harbauer
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany.,Max Planck Institute of Neurobiology, Martinsried, Germany.,Munich Cluster for Systems Neurology, Munich, Germany
| | - Dorothee Dormann
- Institute for Molecular Physiology, Johannes Gutenberg-University Mainz, Mainz, Germany.,Institute of Molecule Biology, Mainz, Germany
| | - Jörn Dengjel
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Dieter Edbauer
- Munich Cluster for Systems Neurology, Medical Faculty, Ludwig-Maximilians-University München, Munich, Germany.,German Center for Neurodegenerative Diseases Munich, Munich, Germany
| | - Christian Behrends
- Munich Cluster for Systems Neurology, Medical Faculty, Ludwig-Maximilians-University München, Munich, Germany
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3
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Dreier JE, Prestel A, Martins JM, Brøndum SS, Nielsen O, Garbers AE, Suga H, Boomsma W, Rogers JM, Hartmann-Petersen R, Kragelund BB. A context-dependent and disordered ubiquitin-binding motif. Cell Mol Life Sci 2022; 79:484. [PMID: 35974206 PMCID: PMC9381478 DOI: 10.1007/s00018-022-04486-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 07/06/2022] [Accepted: 07/14/2022] [Indexed: 02/07/2023]
Abstract
Ubiquitin is a small, globular protein that is conjugated to other proteins as a posttranslational event. A palette of small, folded domains recognizes and binds ubiquitin to translate and effectuate this posttranslational signal. Recent computational studies have suggested that protein regions can recognize ubiquitin via a process of folding upon binding. Using peptide binding arrays, bioinformatics, and NMR spectroscopy, we have uncovered a disordered ubiquitin-binding motif that likely remains disordered when bound and thus expands the palette of ubiquitin-binding proteins. We term this motif Disordered Ubiquitin-Binding Motif (DisUBM) and find it to be present in many proteins with known or predicted functions in degradation and transcription. We decompose the determinants of the motif showing it to rely on features of aromatic and negatively charged residues, and less so on distinct sequence positions in line with its disordered nature. We show that the affinity of the motif is low and moldable by the surrounding disordered chain, allowing for an enhanced interaction surface with ubiquitin, whereby the affinity increases ~ tenfold. Further affinity optimization using peptide arrays pushed the affinity into the low micromolar range, but compromised context dependence. Finally, we find that DisUBMs can emerge from unbiased screening of randomized peptide libraries, featuring in de novo cyclic peptides selected to bind ubiquitin chains. We suggest that naturally occurring DisUBMs can recognize ubiquitin as a posttranslational signal to act as affinity enhancers in IDPs that bind to folded and ubiquitylated binding partners.
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Affiliation(s)
- Jesper E Dreier
- Structural Biology and NMR Laboratory, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark.,REPIN, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark
| | - Andreas Prestel
- Structural Biology and NMR Laboratory, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark
| | - João M Martins
- Department of Computer Science, University of Copenhagen, Universitetsparken 1, 2100, Copenhagen Ø, Denmark
| | - Sebastian S Brøndum
- Structural Biology and NMR Laboratory, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark
| | - Olaf Nielsen
- Functional Genomics, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark
| | - Anna E Garbers
- Structural Biology and NMR Laboratory, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark.,REPIN, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark
| | - Hiroaki Suga
- Department of Chemistry, Graduate School of Science, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Wouter Boomsma
- Department of Computer Science, University of Copenhagen, Universitetsparken 1, 2100, Copenhagen Ø, Denmark
| | - Joseph M Rogers
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 160, 2100, Copenhagen Ø, Denmark
| | - Rasmus Hartmann-Petersen
- REPIN, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark. .,The Linderstrøm Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark.
| | - Birthe B Kragelund
- Structural Biology and NMR Laboratory, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark. .,REPIN, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark. .,The Linderstrøm Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark.
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4
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Becht DC, Leavens MJ, Zeng B, Rothfuss MT, Briknarová K, Bowler BE. Residual Structure in the Denatured State of the Fast-Folding UBA(1) Domain from the Human DNA Excision Repair Protein HHR23A. Biochemistry 2022; 61:767-784. [PMID: 35430812 PMCID: PMC9150713 DOI: 10.1021/acs.biochem.2c00011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The structure of the first ubiquitin-associated domain from HHR23A, UBA(1), was determined by X-ray crystallography at a 1.60 Å resolution, and its stability, folding kinetics, and residual structure under denaturing conditions have been investigated. The concentration dependence of thermal denaturation and size-exclusion chromatography indicate that UBA(1) is monomeric. Guanidine hydrochloride (GdnHCl) denaturation experiments reveal that the unfolding free energy, ΔGu°'(H2O), of UBA(1) is 2.4 kcal mol-1. Stopped-flow folding kinetics indicates sub-millisecond folding with only proline isomerization phases detectable at 25 °C. The full folding kinetics are observable at 4 °C, yielding a folding rate constant, kf, in the absence of a denaturant of 13,000 s-1 and a Tanford β-value of 0.80, consistent with a compact transition state. Evaluation of the secondary structure via circular dichroism shows that the residual helical structure in the denatured state is replaced by polyproline II structure as the GdnHCl concentration increases. Analysis of NMR secondary chemical shifts for backbone 15NH, 13CO, and 13Cα atoms between 4 and 7 M GdnHCl shows three islands of residual helical secondary structure that align in sequence with the three native-state helices. Extrapolation of the NMR data to 0 M GdnHCl demonstrates that helical structure would populate to 17-33% in the denatured state under folding conditions. Comparison with NMR data for a peptide corresponding to helix 1 indicates that this helix is stabilized by transient tertiary interactions in the denatured state of UBA(1). The high helical content in the denatured state, which is enhanced by transient tertiary interactions, suggests a diffusion-collision folding mechanism.
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Affiliation(s)
- Dustin C. Becht
- Department of Chemistry & Biochemistry, University of Montana, Missoula, Montana 59812, United States
- Center for Biomolecular Structure & Dynamics, University of Montana, Missoula, Montana 59812, United States
| | - Moses J. Leavens
- Department of Chemistry & Biochemistry, University of Montana, Missoula, Montana 59812, United States
- Center for Biomolecular Structure & Dynamics, University of Montana, Missoula, Montana 59812, United States
| | - Baisen Zeng
- Department of Chemistry & Biochemistry, University of Montana, Missoula, Montana 59812, United States
- Center for Biomolecular Structure & Dynamics, University of Montana, Missoula, Montana 59812, United States
| | - Michael T. Rothfuss
- Department of Chemistry & Biochemistry, University of Montana, Missoula, Montana 59812, United States
- Center for Biomolecular Structure & Dynamics, University of Montana, Missoula, Montana 59812, United States
| | - Klára Briknarová
- Department of Chemistry & Biochemistry, University of Montana, Missoula, Montana 59812, United States
- Center for Biomolecular Structure & Dynamics, University of Montana, Missoula, Montana 59812, United States
| | - Bruce E. Bowler
- Department of Chemistry & Biochemistry, University of Montana, Missoula, Montana 59812, United States
- Center for Biomolecular Structure & Dynamics, University of Montana, Missoula, Montana 59812, United States
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5
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Ding Y, Wang J, Lu J. miR-337-5p promotes the development of cardiac hypertrophy by targeting Ubiquilin-1 (UBQLN1). Bioengineered 2021; 12:6771-6781. [PMID: 34515612 PMCID: PMC8806775 DOI: 10.1080/21655979.2021.1964892] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Cardiac hypertrophy is an adaptive response of the myocardium to the pressure overload of the heart. MicroRNAs (miRNAs/miRs) are shown to be directly involved in the development of cardiac hypertrophy. However, the function of miR-337-5p and its potential contribution to the serine/threonine-protein kinase, a mammalian target of rapamycin (mTOR) signaling in cardiac hypertrophy remains unknown. In the present study, miR-337-5p expression was examined in cardiomyocytes treated with angiotensin II (Ang II). An adenovirus vector system was employed to knockdown miR-337-5p expression to investigate its functions in cardiac hypertrophy. The results revealed a significant increase in the expression of miR-337-5p in cardiomyocytes treated with Ang II as compared with controls. In addition, downregulation of miR-337-5p expression inhibited cardiac hypertrophy both in vitro and in vivo. Dual-luciferase reporter assays demonstrated Ubiquilin-1 (UBQLN1) as the direct target of miR-337-5p, and revealed its function in the modulation of mTOR signaling. Rescue experiments indicated that UBQLN1 overexpression reversed the effects of miR-337-5p, and further verified this interaction. In summary, the results of the present study show that miR-337-5p silencing attenuates cardiac hypertrophy by targeting UBQLN1. Therefore, miR-337-5p plays a critical role in cardiac hypertrophy and may serve as a new therapeutic target.
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Affiliation(s)
- Ying Ding
- Electrocardiographic Function Department, Xiangyang Central Hospital, Affiliated Hospital Of Hubei University Of Arts And Science, Xiangyang, Hubei, China
| | - Jingyu Wang
- Electrocardiographic Function Department, Xiangyang Central Hospital, Affiliated Hospital Of Hubei University Of Arts And Science, Xiangyang, Hubei, China
| | - Jun Lu
- Electrocardiographic Function Department, Xiangyang Central Hospital, Affiliated Hospital Of Hubei University Of Arts And Science, Xiangyang, Hubei, China
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6
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Kinetic Constraints in the Specific Interaction between Phosphorylated Ubiquitin and Proteasomal Shuttle Factors. Biomolecules 2021; 11:biom11071008. [PMID: 34356632 PMCID: PMC8301994 DOI: 10.3390/biom11071008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 07/05/2021] [Accepted: 07/07/2021] [Indexed: 11/17/2022] Open
Abstract
Ubiquitin (Ub) specifically interacts with the Ub-associating domain (UBA) in a proteasomal shuttle factor, while the latter is involved in either proteasomal targeting or self-assembly coacervation. PINK1 phosphorylates Ub at S65 and makes Ub alternate between C-terminally relaxed (pUbRL) and retracted conformations (pUbRT). Using NMR spectroscopy, we show that pUbRL but not pUbRT preferentially interacts with the UBA from two proteasomal shuttle factors Ubqln2 and Rad23A. Yet discriminatorily, Ubqln2-UBA binds to pUb more tightly than Rad23A does and selectively enriches pUbRL upon complex formation. Further, we determine the solution structure of the complex between Ubqln2-UBA and pUbRL and uncover the thermodynamic basis for the stronger interaction. NMR kinetics analysis at different timescales further suggests an indued-fit binding mechanism for pUb-UBA interaction. Notably, at a relatively low saturation level, the dissociation rate of the UBA-pUbRL complex is comparable with the exchange rate between pUbRL and pUbRT. Thus, a kinetic constraint would dictate the interaction between Ub and UBA, thus fine-tuning the functional state of the proteasomal shuttle factors.
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7
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Cook BW, Lacoursiere RE, Shaw GS. Recruitment of Ubiquitin within an E2 Chain Elongation Complex. Biophys J 2020; 118:1679-1689. [PMID: 32101714 DOI: 10.1016/j.bpj.2020.02.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 02/06/2020] [Accepted: 02/11/2020] [Indexed: 12/26/2022] Open
Abstract
The ubiquitin (Ub) proteolysis pathway uses an E1, E2, and E3 enzyme cascade to label substrate proteins with ubiquitin and target them for degradation. The mechanisms of ubiquitin chain formation remain unclear and include a sequential addition model, in which polyubiquitin chains are built unit by unit on the substrate, or a preassembly model, in which polyubiquitin chains are preformed on the E2 or E3 enzyme and then transferred in one step to the substrate. The E2 conjugating enzyme UBE2K has a 150-residue catalytic core domain and a C-terminal ubiquitin-associated (UBA) domain. Polyubiquitin chains anchored to the catalytic cysteine and free in solution are formed by UBE2K supporting a preassembly model. To study how UBE2K might assemble polyubiquitin chains, we synthesized UBE2K-Ub and UBE2K-Ub2 covalent complexes and analyzed E2 interactions with the covalently attached Ub and Ub2 moieties using NMR spectroscopy. The UBE2K-Ub complex exists in multiple conformations, including the catalytically competent closed state independent of the UBA domain. In contrast, the UBE2K-Ub2 complex takes on a more extended conformation directed by interactions between the classic I44 hydrophobic face of the distal Ub and the conserved MGF hydrophobic patch of the UBA domain. Our results indicate there are distinct differences between the UBE2K-Ub and UBE2K-Ub2 complexes and show how the UBA domain can alter the position of a polyubiquitin chain attached to the UBE2K active site. These observations provide structural insights into the unique Ub chain-building capacity for UBE2K.
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Affiliation(s)
- Benjamin W Cook
- Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada
| | - Rachel E Lacoursiere
- Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada
| | - Gary S Shaw
- Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada.
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8
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Boughton AJ, Krueger S, Fushman D. Branching via K11 and K48 Bestows Ubiquitin Chains with a Unique Interdomain Interface and Enhanced Affinity for Proteasomal Subunit Rpn1. Structure 2020; 28:29-43.e6. [PMID: 31677892 PMCID: PMC6996796 DOI: 10.1016/j.str.2019.10.008] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 09/17/2019] [Accepted: 10/10/2019] [Indexed: 01/04/2023]
Abstract
Post-translational substrate modification with ubiquitin is essential for eukaryotic cellular signaling. Polymeric ubiquitin chains are assembled with specific architectures, which convey distinct signaling outcomes depending on the linkages involved. Recently, branched K11/K48-linked polyubiquitins were shown to enhance proteasomal degradation during mitosis. To better understand the underlying structural mechanisms, we determined the crystal and NMR structures of branched K11/K48-linked tri-ubiquitin and discovered a previously unobserved interdomain interface between the distal ubiquitins. Small-angle neutron scattering and site-directed mutagenesis corroborated the presence of this interface, which we hypothesized to be influential in the physiological role of branched K11/K48-linked chains. Yet, experiments probing polyubiquitin interactions-deubiquitination assays, binding to proteasomal shuttle hHR23A-showed negligible differences between branched K11/K48-linked tri-ubiquitin and related di-ubiquitins. However, significantly stronger binding affinity for branched K11/K48-linked tri-ubiquitin was observed with proteasomal subunit Rpn1, thereby suggesting a functional impact of this interdomain interface and pinpointing the mechanistic site of enhanced degradation.
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Affiliation(s)
- Andrew J Boughton
- Department of Chemistry and Biochemistry, Center for Biomolecular Structure and Organization, University of Maryland, College Park, MD 20742, USA
| | - Susan Krueger
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - David Fushman
- Department of Chemistry and Biochemistry, Center for Biomolecular Structure and Organization, University of Maryland, College Park, MD 20742, USA.
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9
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Non-Proteasomal UbL-UbA Family of Proteins in Neurodegeneration. Int J Mol Sci 2019; 20:ijms20081893. [PMID: 30999567 PMCID: PMC6514573 DOI: 10.3390/ijms20081893] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 04/09/2019] [Accepted: 04/15/2019] [Indexed: 12/11/2022] Open
Abstract
Ubiquitin-like/ubiquitin-associated proteins (UbL-UbA) are a well-studied family of non-proteasomal ubiquitin receptors that are evolutionarily conserved across species. Members of this non-homogenous family facilitate and support proteasomal activity by promoting different effects on proteostasis but exhibit diverse extra-proteasomal activities. Dysfunctional UbL-UbA proteins render cells, particularly neurons, more susceptible to stressors or aging and may cause earlier neurodegeneration. In this review, we summarized the properties and functions of UbL-UbA family members identified to date, with an emphasis on new findings obtained using Drosophila models showing a direct or indirect role in some neurodegenerative diseases.
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10
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Braxton CN, Quartner E, Pawloski W, Fushman D, Cropp TA. Ubiquitin Chains Bearing Genetically Encoded Photo-Cross-Linkers Enable Efficient Covalent Capture of (Poly)ubiquitin-Binding Domains. Biochemistry 2019; 58:883-886. [PMID: 30668904 DOI: 10.1021/acs.biochem.8b01089] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Ubiquitin-mediated signaling pathways regulate essentially every aspect of cell biology in eukaryotes. Ubiquitin receptors typically contain ubiquitin-binding domains (UBDs) that have the ability to recognize monomeric ubiquitin (Ub) and polymeric Ub (polyUb) chains. However, how signaling specificity is achieved remains poorly understood, and many of the UBDs that selectively recognize polyUb chains of particular linkages still need to be identified and characterized. Here we report the incorporation of a genetically encoded photo-cross-linker, p-benzoyl-l-phenylalanine (Bpa), into recombinant Ub and enzymatically synthesized polyUb chains. This allows photo-cross-linking (covalent bond formation) of monoUb and K48- and K63-linked diUb chains to UBDs. This approach provides a framework for understanding Ub cellular signaling through the capture and identification of (poly)Ub-binding proteins.
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Affiliation(s)
- Courtney N Braxton
- Department of Chemistry , Virginia Commonwealth University , 1001 West Main Street , P.O. Box 842006, Richmond , Virginia 23284-2006 , United States
| | - Evan Quartner
- Department of Chemistry and Biochemistry, Center for Biomolecular Structure and Organization , University of Maryland , College Park , Maryland 20742-3360 , United States
| | - Westley Pawloski
- Department of Chemistry and Biochemistry, Center for Biomolecular Structure and Organization , University of Maryland , College Park , Maryland 20742-3360 , United States
| | - David Fushman
- Department of Chemistry and Biochemistry, Center for Biomolecular Structure and Organization , University of Maryland , College Park , Maryland 20742-3360 , United States
| | - T Ashton Cropp
- Department of Chemistry , Virginia Commonwealth University , 1001 West Main Street , P.O. Box 842006, Richmond , Virginia 23284-2006 , United States
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11
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The Roles of Ubiquitin-Binding Protein Shuttles in the Degradative Fate of Ubiquitinated Proteins in the Ubiquitin-Proteasome System and Autophagy. Cells 2019; 8:cells8010040. [PMID: 30634694 PMCID: PMC6357184 DOI: 10.3390/cells8010040] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 12/24/2018] [Accepted: 01/03/2019] [Indexed: 12/15/2022] Open
Abstract
The ubiquitin-proteasome system (UPS) and autophagy are the two major intracellular protein quality control (PQC) pathways that are responsible for cellular proteostasis (homeostasis of the proteome) by ensuring the timely degradation of misfolded, damaged, and unwanted proteins. Ubiquitination serves as the degradation signal in both these systems, but substrates are precisely targeted to one or the other pathway. Determining how and when cells target specific proteins to these two alternative PQC pathways and control the crosstalk between them are topics of considerable interest. The ubiquitin (Ub) recognition code based on the type of Ub-linked chains on substrate proteins was believed to play a pivotal role in this process, but an increasing body of evidence indicates that the PQC pathway choice is also made based on other criteria. These include the oligomeric state of the Ub-binding protein shuttles, their conformation, protein modifications, and the presence of motifs that interact with ATG8/LC3/GABARAP (autophagy-related protein 8/microtubule-associated protein 1A/1B-light chain 3/GABA type A receptor-associated protein) protein family members. In this review, we summarize the current knowledge regarding the Ub recognition code that is bound by Ub-binding proteasomal and autophagic receptors. We also discuss how cells can modify substrate fate by modulating the structure, conformation, and physical properties of these receptors to affect their shuttling between both degradation pathways.
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12
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Terse VL, Gosavi S. The Sensitivity of Computational Protein Folding to Contact Map Perturbations: The Case of Ubiquitin Folding and Function. J Phys Chem B 2018; 122:11497-11507. [PMID: 30234303 DOI: 10.1021/acs.jpcb.8b07409] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Ubiquitin is a small model protein, commonly used in protein folding experiments and simulations. We simulated ubiquitin using a well-tested structure-based model coarse-grained to a Cα level (Cα-SBM) and found that the simulated folding route did not agree with the experimentally observed one. Simulating the Cα-SBM with a cutoff contact map, instead of a screened contact map, switched the folding route with the new route matching the experimental route. Thus, the simulated folding of ubiquitin is sensitive to contact map definition. The screened contact map, which is used in folding simulations because it captures protein folding cooperativity, removes contacts in which the atoms in contact are occluded by a third atom and is less sensitive to the value of the cutoff distance in well-packed regions of the protein. In sparsely packed regions, the larger cutoff distance creates bridging contacts between atoms which are separated by voids. Such contacts do not seem to affect the folding of most proteins, including those of the ubiquitin fold. However, the surface of ubiquitin has several protruding functional side chains which naturally create bridging contacts. Together, our results show that subtle structural features of a protein that may not be apparent by mere observation can be identified by comparing folding simulations of SBMs in which these features are differently encoded. When such structural features are preserved for functional reasons, differences in computational folding can be leveraged to identify functional features. Notably, such features are accessible to a gradation of SBMs even in commonly studied proteins such as ubiquitin.
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Affiliation(s)
- Vishram L Terse
- Simons Centre for the Study of Living Machines , National Centre for Biological Sciences , Tata Institute of Fundamental Research, Bangalore 560065 , India
| | - Shachi Gosavi
- Simons Centre for the Study of Living Machines , National Centre for Biological Sciences , Tata Institute of Fundamental Research, Bangalore 560065 , India
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13
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Structural insights into pro-aggregation effects of C. elegans CRAM-1 and its human ortholog SERF2. Sci Rep 2018; 8:14891. [PMID: 30291272 PMCID: PMC6173753 DOI: 10.1038/s41598-018-33143-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 09/19/2018] [Indexed: 12/20/2022] Open
Abstract
Toxic protein aggregates are key features of progressive neurodegenerative diseases. In addition to “seed” proteins diagnostic for each neuropathy (e.g., Aβ1–42 and tau in Alzheimer’s disease), aggregates contain numerous other proteins, many of which are common to aggregates from diverse diseases. We reported that CRAM-1, discovered in insoluble aggregates of C. elegans expressing Q40::YFP, blocks proteasomal degradation of ubiquitinated proteins and thus promotes aggregation. We now show that CRAM-1 contains three α-helical segments forming a UBA-like domain, structurally similar to those of mammalian adaptor proteins (e.g. RAD23, SQSTM1/p62) that shuttle ubiquitinated cargos to proteasomes or autophagosomes for degradation. Molecular modeling indicates that CRAM-1, through this UBA-like domain, can form tight complexes with mono- and di-ubiquitin and may thus prevent tagged proteins from interacting with adaptor/shuttle proteins required for degradation. A human ortholog of CRAM-1, SERF2 (also largely disordered), promotes aggregation in SH-SY5Y-APPSw human neuroblastoma cells, since SERF2 knockdown protects these cells from amyloid formation. Atomistic molecular-dynamic simulations predict spontaneous unfolding of SERF2, and computational large-scale protein-protein interactions predict its stable binding to ubiquitins. SERF2 is also predicted to bind to most proteins screened at random, although with lower average stability than to ubiquitins, suggesting roles in aggregation initiation and/or progression.
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14
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Kurlawala Z, Shah PP, Shah C, Beverly LJ. The STI and UBA Domains of UBQLN1 Are Critical Determinants of Substrate Interaction and Proteostasis. J Cell Biochem 2017; 118:2261-2270. [PMID: 28075048 DOI: 10.1002/jcb.25880] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 01/10/2017] [Indexed: 01/24/2023]
Abstract
There are five Ubiquilin proteins (UBQLN1-4, UBQLN-L), which are evolutionarily conserved and structurally similar. UBQLN proteins have three functional domains: N-terminal ubiquitin-like domain (UBL), C-terminal ubiquitin-associated domain (UBA), and STI chaperone-like regions in the middle. Alterations in UBQLN1 gene have been detected in a variety of disorders ranging from Alzheimer's disease to cancer. UBQLN1 has been largely studied in neurodegenerative disorders in the context of protein quality control. Several studies have hypothesized that the UBA domain of UBQLN1 binds to poly-ubiquitin chains of substrate and shuttles it to the proteasome via its UBL domain for degradation. UBQLN1 either facilitates degradation (Ataxin3, EPS15) or stabilizes (PSEN1/2, BCLb) substrates it binds to. The signal that determines this fate is unknown and there is conflicting data to support the existing working model of UBQLN1. Using BCLb as a model substrate, we characterized UBQLN1-substrate interaction. We identified the first two STI domains of UBQLN1 as critical for binding to BCLb. Interaction of UBQLN1 with BCLb is independent of ubiquitination of BCLb, but interaction with ubiquitin via UBA domain is required for stabilization of BCLb. Similarly, we showed that UBQLN1 interacts with IGF1R and ESYT2 through the STI domains and stabilizes these proteins through its UBA domain. Interactions that are not dependent on STI domains, for example, UBL mediated interaction with PSMD4 and BAG6, do not appear to be stabilized by UBQLN1. We conclude that fate of substrates that UBQLN1 associates with, is interaction domain specific. J. Cell. Biochem. 118: 2261-2270, 2017. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Zimple Kurlawala
- James Graham Brown Cancer Center, University of Louisville, Louisville, Kentucky.,Department of Pharmacology and Toxicology, School of Medicine, University of Louisville, Louisville, Kentucky
| | - Parag P Shah
- James Graham Brown Cancer Center, University of Louisville, Louisville, Kentucky
| | - Charmi Shah
- James Graham Brown Cancer Center, University of Louisville, Louisville, Kentucky
| | - Levi J Beverly
- James Graham Brown Cancer Center, University of Louisville, Louisville, Kentucky.,Department of Pharmacology and Toxicology, School of Medicine, University of Louisville, Louisville, Kentucky.,Division of Hematology and Oncology, School of Medicine, University of Louisville, Louisville, Kentucky
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15
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Jiang WX, Gu XH, Dong X, Tang C. Lanthanoid tagging via an unnatural amino acid for protein structure characterization. JOURNAL OF BIOMOLECULAR NMR 2017; 67:273-282. [PMID: 28365903 DOI: 10.1007/s10858-017-0106-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Accepted: 03/28/2017] [Indexed: 06/07/2023]
Abstract
Lanthanoid pseudo-contact shift (PCS) provides long-range structural information between a paramagnetic tag and protein nuclei. However, for proteins with native cysteines, site-specific attachment may only utilize functional groups orthogonal to sulfhydryl chemistry. Here we report two lanthanoid probes, DTTA-C3-yne and DTTA-C4-yne, which can be conjugated to an unnatural amino acid pAzF in the target protein via azide-alkyne cycloaddition. Demonstrated with ubiquitin and cysteine-containing enzyme EIIB, we show that large PCSs of distinct profiles can be generated for each tag/lanthanoid combination. The DTTA-based lanthanoid tags are associated with large magnetic susceptibility tensors owing to the rigidity of the tags. In particular, introduction of the DTTA-C3 tag affords intermolecular PCSs and enables structural characterization of a transient protein complex between ubiquitin and a UBA domain. Together, we have expanded the repertoire of paramagnetic tags and the applicability of paramagnetic NMR.
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Affiliation(s)
- Wen-Xue Jiang
- CAS Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic Molecular Physics, National Center for Magnetic Resonance at Wuhan, Collaborative Innovation Center of Chemistry for Life Sciences, Wuhan Institute of Physics and Mathematics of the Chinese Academy of Sciences, Wuhan, 430071, Hubei, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xin-Hua Gu
- CAS Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic Molecular Physics, National Center for Magnetic Resonance at Wuhan, Collaborative Innovation Center of Chemistry for Life Sciences, Wuhan Institute of Physics and Mathematics of the Chinese Academy of Sciences, Wuhan, 430071, Hubei, China
| | - Xu Dong
- CAS Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic Molecular Physics, National Center for Magnetic Resonance at Wuhan, Collaborative Innovation Center of Chemistry for Life Sciences, Wuhan Institute of Physics and Mathematics of the Chinese Academy of Sciences, Wuhan, 430071, Hubei, China.
| | - Chun Tang
- CAS Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic Molecular Physics, National Center for Magnetic Resonance at Wuhan, Collaborative Innovation Center of Chemistry for Life Sciences, Wuhan Institute of Physics and Mathematics of the Chinese Academy of Sciences, Wuhan, 430071, Hubei, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
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16
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Munari F, Bortot A, Zanzoni S, D'Onofrio M, Fushman D, Assfalg M. Identification of primary and secondary UBA footprints on the surface of ubiquitin in cell-mimicking crowded solution. FEBS Lett 2017; 591:979-990. [PMID: 28267209 DOI: 10.1002/1873-3468.12615] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2016] [Revised: 02/24/2017] [Accepted: 02/24/2017] [Indexed: 01/09/2023]
Abstract
Despite significant advancements in our understanding of ubiquitin-mediated signaling, the influence of the intracellular environment on the formation of transient ubiquitin-partner complexes remains poorly explored. In our work, we introduce macromolecular crowding as a first level of complexity toward the imitation of a cellular environment in the study of such interactions. Using NMR spectroscopy, we find that the stereospecific complex of ubiquitin and the ubiquitin-associated domain (UBA) is minimally perturbed by the crowding agent Ficoll. However, in addition to the primary canonical recognition patch on ubiquitin, secondary patches are identified, indicating that in cell-mimicking crowded solution, UBA contacts ubiquitin at multiple sites.
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Affiliation(s)
| | - Andrea Bortot
- Department of Biotechnology, University of Verona, Italy
| | - Serena Zanzoni
- Department of Biotechnology, University of Verona, Italy
| | | | - David Fushman
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD, USA
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17
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Chojnacki M, Mansour W, Hameed DS, Singh RK, El Oualid F, Rosenzweig R, Nakasone MA, Yu Z, Glaser F, Kay LE, Fushman D, Ovaa H, Glickman MH. Polyubiquitin-Photoactivatable Crosslinking Reagents for Mapping Ubiquitin Interactome Identify Rpn1 as a Proteasome Ubiquitin-Associating Subunit. Cell Chem Biol 2017; 24:443-457.e6. [PMID: 28330605 DOI: 10.1016/j.chembiol.2017.02.013] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Revised: 12/29/2016] [Accepted: 02/23/2017] [Indexed: 01/05/2023]
Abstract
Ubiquitin (Ub) signaling is a diverse group of processes controlled by covalent attachment of small protein Ub and polyUb chains to a range of cellular protein targets. The best documented Ub signaling pathway is the one that delivers polyUb proteins to the 26S proteasome for degradation. However, studies of molecular interactions involved in this process have been hampered by the transient and hydrophobic nature of these interactions and the lack of tools to study them. Here, we develop Ub-phototrap (UbPT), a synthetic Ub variant containing a photoactivatable crosslinking side chain. Enzymatic polymerization into chains of defined lengths and linkage types provided a set of reagents that led to identification of Rpn1 as a third proteasome ubiquitin-associating subunit that coordinates docking of substrate shuttles, unloading of substrates, and anchoring of polyUb conjugates. Our work demonstrates the value of UbPT, and we expect that its future uses will help define and investigate the ubiquitin interactome.
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Affiliation(s)
- Michal Chojnacki
- Department of Biology, Technion-Israel Institute of Technology, 32000 Haifa, Israel; Department of Medical Biochemistry, Medical University of Łódź, Łódź, Poland
| | - Wissam Mansour
- Department of Biology, Technion-Israel Institute of Technology, 32000 Haifa, Israel
| | - Dharjath S Hameed
- Division of Cell Biology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, the Netherlands; Department of Chemical Immunology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, the Netherlands
| | - Rajesh K Singh
- Department of Chemistry and Biochemistry, Center for Biomolecular Structure and Organization, University of Maryland, College Park, MD 20742, USA
| | - Farid El Oualid
- Division of Cell Biology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, the Netherlands
| | - Rina Rosenzweig
- Departments of Molecular Genetics, Biochemistry and Chemistry, The University of Toronto, Toronto, ON M5S 1A8, Canada; Department of Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Mark A Nakasone
- Department of Biology, Technion-Israel Institute of Technology, 32000 Haifa, Israel
| | - Zanlin Yu
- Department of Biology, Technion-Israel Institute of Technology, 32000 Haifa, Israel
| | - Fabian Glaser
- The Technion Bioinformatics Knowledge Unit (BKU) of the Lorry Lokey Interdisciplinary Center for Life Sciences and Engineering, Technion-Israel Institute of Technology, 32000 Haifa, Israel
| | - Lewis E Kay
- Departments of Molecular Genetics, Biochemistry and Chemistry, The University of Toronto, Toronto, ON M5S 1A8, Canada
| | - David Fushman
- Department of Chemistry and Biochemistry, Center for Biomolecular Structure and Organization, University of Maryland, College Park, MD 20742, USA.
| | - Huib Ovaa
- Division of Cell Biology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, the Netherlands; Department of Chemical Immunology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, the Netherlands.
| | - Michael H Glickman
- Department of Biology, Technion-Israel Institute of Technology, 32000 Haifa, Israel.
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18
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Castañeda CA, Dixon EK, Walker O, Chaturvedi A, Nakasone MA, Curtis JE, Reed MR, Krueger S, Cropp TA, Fushman D. Linkage via K27 Bestows Ubiquitin Chains with Unique Properties among Polyubiquitins. Structure 2016; 24:423-36. [PMID: 26876099 DOI: 10.1016/j.str.2016.01.007] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 12/18/2015] [Accepted: 01/05/2016] [Indexed: 12/20/2022]
Abstract
Polyubiquitination, a critical protein post-translational modification, signals for a diverse set of cellular events via the different isopeptide linkages formed between the C terminus of one ubiquitin (Ub) and the ɛ-amine of K6, K11, K27, K29, K33, K48, or K63 of a second Ub. We assembled di-ubiquitins (Ub2) comprising every lysine linkage and examined them biochemically and structurally. Of these, K27-Ub2 is unique as it is not cleaved by most deubiquitinases. As this remains the only structurally uncharacterized lysine linkage, we comprehensively examined the structures and dynamics of K27-Ub2 using nuclear magnetic resonance, small-angle neutron scattering, and in silico ensemble modeling. Our structural data provide insights into the functional properties of K27-Ub2, in particular that K27-Ub2 may be specifically recognized by K48-selective receptor UBA2 domain from proteasomal shuttle protein hHR23a. Binding studies and mutagenesis confirmed this prediction, further highlighting structural/recognition versatility of polyubiquitins and the potential power of determining function from elucidation of conformational ensembles.
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Affiliation(s)
- Carlos A Castañeda
- Department of Chemistry and Biochemistry, Center for Biomolecular Structure and Organization, University of Maryland, College Park, MD 20742, USA; Departments of Biology & Chemistry, Syracuse University, Syracuse, NY 13244, USA.
| | - Emma K Dixon
- Department of Chemistry and Biochemistry, Center for Biomolecular Structure and Organization, University of Maryland, College Park, MD 20742, USA
| | - Olivier Walker
- Institut des Sciences Analytiques, UMR5280-Université de Lyon, 69100 Villeurbanne, France
| | - Apurva Chaturvedi
- Department of Chemistry and Biochemistry, Center for Biomolecular Structure and Organization, University of Maryland, College Park, MD 20742, USA
| | - Mark A Nakasone
- Department of Chemistry and Biochemistry, Center for Biomolecular Structure and Organization, University of Maryland, College Park, MD 20742, USA
| | - Joseph E Curtis
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899-8562, USA
| | - Megan R Reed
- Department of Chemistry, Virginia Commonwealth University, Richmond, VA 23284, USA
| | - Susan Krueger
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899-8562, USA
| | - T Ashton Cropp
- Department of Chemistry, Virginia Commonwealth University, Richmond, VA 23284, USA
| | - David Fushman
- Department of Chemistry and Biochemistry, Center for Biomolecular Structure and Organization, University of Maryland, College Park, MD 20742, USA.
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19
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Transient Interactions of a Cytosolic Protein with Macromolecular and Vesicular Cosolutes: Unspecific and Specific Effects. Chembiochem 2015; 16:2633-45. [DOI: 10.1002/cbic.201500451] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Indexed: 01/04/2023]
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20
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Jiao R, Postnikoff S, Harkness TA, Arnason TG. The SNF1 Kinase Ubiquitin-associated Domain Restrains Its Activation, Activity, and the Yeast Life Span. J Biol Chem 2015; 290:15393-15404. [PMID: 25869125 DOI: 10.1074/jbc.m115.647032] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Indexed: 02/04/2023] Open
Abstract
The enzyme family of heterotrimeric AMP-dependent protein kinases is activated upon low energy states, conferring a switch toward energy-conserving metabolic pathways through immediate kinase actions on enzyme targets and delayed alterations in gene expression through its nuclear relocalization. This family is evolutionarily conserved, including the presence of a ubiquitin-associated (UBA) motif in most catalytic subunits. The potential for the UBA domain to promote protein associations or direct subcellular location, as seen in other UBA-containing proteins, led us to query whether the UBA domain within the yeast AMP-dependent protein kinase ortholog, SNF1 kinase, was important in these aspects of its regulation. Here, we demonstrate that conserved UBA motif mutations significantly alter SNF1 kinase activation and biological activity, including enhanced allosteric subunit associations and increased oxidative stress resistance and life span. Significantly, the enhanced UBA-dependent longevity and oxidative stress response are at least partially dependent on the Fkh1 and Fkh2 stress response transcription factors, which in turn are shown to influence Snf1 gene expression.
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Affiliation(s)
- Rubin Jiao
- Departments of Anatomy and Cell Biology and University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada
| | - Spike Postnikoff
- Departments of Anatomy and Cell Biology and University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada
| | - Troy A Harkness
- Departments of Anatomy and Cell Biology and University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada
| | - Terra G Arnason
- Departments of Anatomy and Cell Biology and University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada; Medicine, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada.
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21
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Castañeda CA, Kashyap TR, Nakasone MA, Krueger S, Fushman D. Unique structural, dynamical, and functional properties of k11-linked polyubiquitin chains. Structure 2014; 21:1168-81. [PMID: 23823328 DOI: 10.1016/j.str.2013.04.029] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2012] [Revised: 04/05/2013] [Accepted: 04/26/2013] [Indexed: 11/24/2022]
Abstract
K11-linked polyubiquitin chains play important signaling and regulatory roles in both degradative and nonproteolytic pathways in eukaryotes. To understand the structural basis of how these chains are recognized and distinguished from other polyubiquitins, we determined solution structures of K11-linked diubiquitin (K11-Ub2) in the absence and presence of salt. These structures reveal that K11-Ub2 adopts conformations distinct from those of K48-linked or K63-linked chains. Importantly, our solution NMR and SANS data are inconsistent with published crystal structures of K11-Ub2. We found that increasing salt concentration compacts K11-Ub2 and strengthens interactions between the two Ub units. Binding studies indicate that K11-Ub2 interacts with ubiquitin-receptor proteins from both proteasomal and nonproteasomal pathways but with intermediate affinity and different binding modes than either K48-linked or K63-linked diubiquitin. Our data support the hypothesis that polyubiquitin chains of different linkages possess unique conformational and dynamical properties, allowing them to be recognized differently by downstream receptor proteins.
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Affiliation(s)
- Carlos A Castañeda
- Department of Chemistry and Biochemistry, Center for Biomolecular Structure and Organization, University of Maryland, College Park, MD 20742, USA
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22
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Cho YS, Yoo J, Park S, Cho HS. The structures of the kinase domain and UBA domain of MPK38 suggest the activation mechanism for kinase activity. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2014; 70:514-21. [PMID: 24531485 PMCID: PMC3940201 DOI: 10.1107/s1399004713027806] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Accepted: 10/10/2013] [Indexed: 12/20/2022]
Abstract
Murine protein serine/threonine kinase 38 (MPK38) is the murine orthologue of human maternal embryonic leucine-zipper kinase (MELK), which belongs to the SNF1/AMPK family. MELK is considered to be a promising drug target for anticancer therapy because overexpression and hyperactivation of MELK is correlated with several human cancers. Activation of MPK38 requires the extended sequence (ExS) containing the ubiquitin-associated (UBA) linker and UBA domain and phosphorylation of the activation loop. However, the activation mechanism of MPK38 is unknown. This paper reports the crystal structure of MPK38 (T167E), which mimics a phosphorylated state of the activation loop, in complex with AMP-PNP. In the MPK38 structure, the UBA linker forces an inward movement of the αC helix. Phosphorylation of the activation loop then induces movement of the activation loop towards the C-lobe and results in interlobar cleft closure. These processes generate a fully active state of MPK38. This structure suggests that MPK38 has a similar molecular mechanism regulating activation as in other kinases of the SNF1/AMPK family.
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Affiliation(s)
- Yong-Soon Cho
- Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Republic of Korea
| | - Jiho Yoo
- Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Republic of Korea
| | - Soomin Park
- Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Republic of Korea
| | - Hyun-Soo Cho
- Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Republic of Korea
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23
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Jung J, Byeon IJL, DeLucia M, Koharudin LMI, Ahn J, Gronenborn AM. Binding of HIV-1 Vpr protein to the human homolog of the yeast DNA repair protein RAD23 (hHR23A) requires its xeroderma pigmentosum complementation group C binding (XPCB) domain as well as the ubiquitin-associated 2 (UBA2) domain. J Biol Chem 2013; 289:2577-88. [PMID: 24318982 DOI: 10.1074/jbc.m113.534453] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The human homolog of the yeast DNA repair protein RAD23, hHR23A, has been found previously to interact with the human immunodeficiency virus, type 1 accessory protein Vpr. hHR23A is a modular protein containing an N-terminal ubiquitin-like (UBL) domain and two ubiquitin-associated domains (UBA1 and UBA2) separated by a xeroderma pigmentosum complementation group C binding (XPCB) domain. All domains are connected by flexible linkers. hHR23A binds ubiquitinated proteins and acts as a shuttling factor to the proteasome. Here, we show that hHR23A utilizes both the UBA2 and XPCB domains to form a stable complex with Vpr, linking Vpr directly to cellular DNA repair pathways and their probable exploitation by the virus. Detailed structural mapping of the Vpr contacts on hHR23A, by NMR, revealed substantial contact surfaces on the UBA2 and XPCB domains. In addition, Vpr binding disrupts an intramolecular UBL-UBA2 interaction. We also show that Lys-48-linked di-ubiquitin, when binding to UBA1, does not release the bound Vpr from the hHR23A-Vpr complex. Instead, a ternary hHR23A·Vpr·di-Ub(K48) complex is formed, indicating that Vpr does not necessarily abolish hHR23A-mediated shuttling to the proteasome.
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Affiliation(s)
- Jinwon Jung
- From the Department of Structural Biology and Pittsburgh Center for HIV-Host Protein Interactions, University of Pittsburgh, School of Medicine, Pittsburgh, Pennsylvania 15261
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24
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Rea SL, Walsh JP, Layfield R, Ratajczak T, Xu J. New insights into the role of sequestosome 1/p62 mutant proteins in the pathogenesis of Paget's disease of bone. Endocr Rev 2013; 34:501-24. [PMID: 23612225 DOI: 10.1210/er.2012-1034] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Paget's disease of bone (PDB) is characterized by focal areas of aberrant and excessive bone turnover, specifically increased bone resorption and disorganized bone formation. Germline mutations in the sequestosome 1/p62 (SQSTM1/p62) gene are common in PDB patients, with most mutations affecting the ubiquitin-associated domain of the protein. In vitro, osteoclast precursor cells expressing PDB-mutant SQSTM1/p62 protein are associated with increases in nuclear factor κB activation, osteoclast differentiation, and bone resorption. Although the precise mechanisms by which SQSTM1/p62 mutations contribute to disease pathogenesis and progression are not well defined, it is apparent that as well as affecting nuclear factor κB signaling, SQSTM1/p62 is a master regulator of ubiquitinated protein turnover via autophagy and the ubiquitin-proteasome system. Additional roles for SQSTM1/p62 in the oxidative stress-induced Keap1/Nrf2 pathway and in caspase-mediated apoptosis that were recently reported are potentially relevant to the pathogenesis of PDB. Thus, SQSTM1/p62 may serve as a molecular link or switch between autophagy, apoptosis, and cell survival signaling. The purpose of this review is to outline recent advances in understanding of the multiple pathophysiological roles of SQSTM1/p62 protein, with particular emphasis on their relationship to PDB, including challenges associated with translating SQSTM1/p62 research into clinical diagnosis and treatment.
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Affiliation(s)
- Sarah L Rea
- Department of Endocrinology and Diabetes, Level 1, C Block, Sir Charles Gairdner Hospital, Hospital Avenue, Nedlands, Western Australia 6009, Australia.
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25
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Arena G, Bellia F, Frasca G, Grasso G, Lanza V, Rizzarelli E, Tabbì G, Zito V, Milardi D. Inorganic Stressors of Ubiquitin. Inorg Chem 2013; 52:9567-73. [DOI: 10.1021/ic401276x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Giuseppe Arena
- Dipartimento di Scienze Chimiche, Università degli Studi di Catania, Viale Andrea
Doria 6, 95125 Catania, Italy
| | - Francesco Bellia
- Istituto di Biostrutture e Bioimmagini
UOS—CT, Consiglio Nazionale delle Ricerche, Viale Andrea Doria 6, 95125 Catania, Italy
| | - Giuseppina Frasca
- Istituto di Biostrutture e Bioimmagini
UOS—CT, Consiglio Nazionale delle Ricerche, Viale Andrea Doria 6, 95125 Catania, Italy
| | - Giulia Grasso
- Istituto di Biostrutture e Bioimmagini
UOS—CT, Consiglio Nazionale delle Ricerche, Viale Andrea Doria 6, 95125 Catania, Italy
| | - Valeria Lanza
- Istituto di Biostrutture e Bioimmagini
UOS—CT, Consiglio Nazionale delle Ricerche, Viale Andrea Doria 6, 95125 Catania, Italy
| | - Enrico Rizzarelli
- Dipartimento di Scienze Chimiche, Università degli Studi di Catania, Viale Andrea
Doria 6, 95125 Catania, Italy
- Istituto di Biostrutture e Bioimmagini
UOS—CT, Consiglio Nazionale delle Ricerche, Viale Andrea Doria 6, 95125 Catania, Italy
| | - Giovanni Tabbì
- Istituto di Biostrutture e Bioimmagini
UOS—CT, Consiglio Nazionale delle Ricerche, Viale Andrea Doria 6, 95125 Catania, Italy
| | - Valeria Zito
- Istituto di Biostrutture e Bioimmagini
UOS—CT, Consiglio Nazionale delle Ricerche, Viale Andrea Doria 6, 95125 Catania, Italy
| | - Danilo Milardi
- Istituto di Biostrutture e Bioimmagini
UOS—CT, Consiglio Nazionale delle Ricerche, Viale Andrea Doria 6, 95125 Catania, Italy
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Lloyd SJA, Raychaudhuri S, Espenshade PJ. Subunit architecture of the Golgi Dsc E3 ligase required for sterol regulatory element-binding protein (SREBP) cleavage in fission yeast. J Biol Chem 2013; 288:21043-21054. [PMID: 23760507 DOI: 10.1074/jbc.m113.468215] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The membrane-bound sterol regulatory element-binding protein (SREBP) transcription factors regulate lipogenesis in mammalian cells and are activated through sequential cleavage by the Golgi-localized Site-1 and Site-2 proteases. The mechanism of fission yeast SREBP cleavage is less well defined and, in contrast, requires the Golgi-localized Dsc E3 ligase complex. The Dsc E3 ligase consists of five integral membrane subunits, Dsc1 through Dsc5, and resembles membrane E3 ligases that function in endoplasmic reticulum-associated degradation. Using immunoprecipitation assays and blue native electrophoresis, we determined the subunit architecture for the complex of Dsc1 through Dsc5, showing that the Dsc proteins form subcomplexes and display defined connectivity. Dsc2 is a rhomboid pseudoprotease family member homologous to mammalian UBAC2 and a central component of the Dsc E3 ligase. We identified conservation in the architecture of the Dsc E3 ligase and the multisubunit E3 ligase gp78 in mammals. Specifically, Dsc1-Dsc2-Dsc5 forms a complex resembling gp78-UBAC2-UBXD8. Further characterization of Dsc2 revealed that its C-terminal UBA domain can bind to ubiquitin chains but that the Dsc2 UBA domain is not essential for yeast SREBP cleavage. Based on the ability of rhomboid superfamily members to bind transmembrane proteins, we speculate that Dsc2 functions in SREBP recognition and binding. Homologs of Dsc1 through Dsc4 are required for SREBP cleavage and virulence in the human opportunistic pathogen Aspergillus fumigatus. Thus, these studies advance our organizational understanding of multisubunit E3 ligases involved in endoplasmic reticulum-associated degradation and fungal pathogenesis.
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Affiliation(s)
- S Julie-Ann Lloyd
- From the Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Sumana Raychaudhuri
- From the Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Peter J Espenshade
- From the Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205.
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27
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Singh RK, Zerath S, Kleifeld O, Scheffner M, Glickman MH, Fushman D. Recognition and cleavage of related to ubiquitin 1 (Rub1) and Rub1-ubiquitin chains by components of the ubiquitin-proteasome system. Mol Cell Proteomics 2012; 11:1595-611. [PMID: 23105008 DOI: 10.1074/mcp.m112.022467] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Of all ubiquitin-like proteins, Rub1 (Nedd8 in mammals) is the closest kin of ubiquitin. We show via NMR that structurally, Rub1 and ubiquitin are fundamentally similar as well. Despite these profound similarities, the prevalence of Rub1/Nedd8 and of ubiquitin as modifiers of the proteome is starkly different, and their attachments to specific substrates perform different functions. Recently, some proteins, including p53, p73, EGFR, caspase-7, and Parkin, have been shown to be modified by both Rub1/Nedd8 and ubiquitin within cells. To understand whether and how it might be possible to distinguish among the same target protein modified by Rub1 or ubiquitin or both, we examined whether ubiquitin receptors can differentiate between Rub1 and ubiquitin. Surprisingly, Rub1 interacts with proteasome ubiquitin-shuttle proteins comparably to ubiquitin but binds more weakly to a proteasomal ubiquitin receptor Rpn10. We identified Rub1-ubiquitin heteromers in yeast and Nedd8-Ub heteromers in human cells. We validate that in human cells and in vitro, human Rub1 (Nedd8) forms chains with ubiquitin where it acts as a chain terminator. Interestingly, enzymatically assembled K48-linked Rub1-ubiquitin heterodimers are recognized by various proteasomal ubiquitin shuttles and receptors comparably to K48-linked ubiquitin homodimers. Furthermore, these heterologous chains are cleaved by COP9 signalosome or 26S proteasome. A derubylation function of the proteasome expands the repertoire of its enzymatic activities. In contrast, Rub1 conjugates may be somewhat resilient to the actions of other canonical deubiquitinating enzymes. Taken together, these findings suggest that once Rub1/Nedd8 is channeled into ubiquitin pathways, it is recognized essentially like ubiquitin.
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Affiliation(s)
- Rajesh K Singh
- Department of Chemistry and Biochemistry, Center for Biomolecular Structure and Organization, University of Maryland, College Park, MD 20742, USA
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28
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Lai MY, Zhang D, Laronde-Leblanc N, Fushman D. Structural and biochemical studies of the open state of Lys48-linked diubiquitin. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1823:2046-56. [PMID: 22542781 DOI: 10.1016/j.bbamcr.2012.04.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Revised: 04/10/2012] [Accepted: 04/11/2012] [Indexed: 01/05/2023]
Abstract
Ubiquitin (Ub) is a small protein highly conserved among eukaryotes and involved in practically all aspects of eukaryotic cell biology. Polymeric chains assembled from covalently-linked Ub monomers function as molecular signals in the regulation of a host of cellular processes. Our previous studies have shown that the predominant state of Lys48-linked di- and tetra-Ub chains at near-physiological conditions is a closed conformation, in which the Ub-Ub interface is formed by the hydrophobic surface residues of the adjacent Ub units. Because these very residues are involved in (poly)Ub interactions with the majority of Ub-binding proteins, their sequestration at the Ub-Ub interface renders the closed conformation of polyUb binding incompetent. Thus the existence of open conformation(s) and the interdomain motions opening and closing the Ub-Ub interface is critical for the recognition of Lys48-linked polyUb by its receptors. Knowledge of the conformational properties of a polyUb signal is essential for our understanding of its specific recognition by various Ub-receptors. Despite their functional importance, open states of Lys48-linked chains are poorly characterized. Here we report a crystal structure of the open state of Lys48-linked di-Ub. Moreover, using NMR, we examined interactions of the open state of this chain (at pH4.5) with a Lys48-linkage-selective receptor, the UBA2 domain of a shuttle protein hHR23a. Our results show that di-Ub binds UBA2 in the same mode and with comparable affinity as the closed state. Our data suggest a mechanism for polyUb signal recognition, whereby Ub-binding proteins select specific conformations out of the available ensemble of polyUb chain conformations. This article is part of a Special Issue entitled: Ubiquitin Drug Discovery and Diagnostics.
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Affiliation(s)
- Ming-Yih Lai
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA
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29
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Zhang YH, Zhou CJ, Zhou ZR, Song AX, Hu HY. Domain analysis reveals that a deubiquitinating enzyme USP13 performs non-activating catalysis for Lys63-linked polyubiquitin. PLoS One 2011; 6:e29362. [PMID: 22216260 PMCID: PMC3247260 DOI: 10.1371/journal.pone.0029362] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2011] [Accepted: 11/27/2011] [Indexed: 11/18/2022] Open
Abstract
Deubiquitination is a reverse process of cellular ubiquitination important for many biological events. Ubiquitin (Ub)-specific protease 13 (USP13) is an ortholog of USP5 implicated in catalyzing hydrolysis of various Ub chains, but its enzymatic properties and catalytic regulation remain to be explored. Here we report studies of the roles of the Ub-binding domains of USP13 in regulatory catalysis by biochemical and NMR structural approaches. Our data demonstrate that USP13, distinct from USP5, exhibits a weak deubiquitinating activity preferring to Lys63-linked polyubiquitin (K63-polyUb) in a non-activation manner. The zinc finger (ZnF) domain of USP13 shares a similar fold with that of USP5, but it cannot bind with Ub, so that USP13 has lost its ability to be activated by free Ub. Substitution of the ZnF domain with that of USP5 confers USP13 the property of catalytic activation. The tandem Ub-associated (UBA) domains of USP13 can bind with different types of diUb but preferentially with K63-linked, providing a possible explanation for the weak activity preferring to K63-polyUb. USP13 can also regulate the protein level of CD3δ in cells, probably depending on its weak deubiquitinating activity and the Ub-binding properties of the UBA domains. Thus, the non-activating catalysis of USP13 for K63-polyUb chains implies that it may function differently from USP5 in cellular deubiquitination processes.
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Affiliation(s)
- Yu-Hang Zhang
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Chen-Jie Zhou
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Zi-Ren Zhou
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Ai-Xin Song
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Hong-Yu Hu
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
- * E-mail:
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30
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Tse MK, Hui SK, Yang Y, Yin ST, Hu HY, Zou B, Wong BCY, Sze KH. Structural analysis of the UBA domain of X-linked inhibitor of apoptosis protein reveals different surfaces for ubiquitin-binding and self-association. PLoS One 2011; 6:e28511. [PMID: 22194841 PMCID: PMC3240630 DOI: 10.1371/journal.pone.0028511] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2011] [Accepted: 11/09/2011] [Indexed: 12/18/2022] Open
Abstract
Background Inhibitor of apoptosis proteins (IAPs) belong to a pivotal antiapoptotic protein family that plays a crucial role in tumorigenesis, cancer progression, chemoresistance and poor patient-survival. X-linked inhibitor of apoptosis protein (XIAP) is a prominent member of IAPs attracting intense research because it has been demonstrated to be a physiological inhibitor of caspases and apoptosis. Recently, an evolutionarily conserved ubiquitin-associated (UBA) domain was identified in XIAP and a number of RING domain-bearing IAPs. This has placed the IAPs in the group of ubiquitin binding proteins. Here, we explore the three-dimensional structure of the XIAP UBA domain (XIAP-UBA) and how it interacts with mono-ubiquitin and diubiquitin conjugates. Principal Findings The solution structure of the XIAP-UBA domain was determined by NMR spectroscopy. XIAP-UBA adopts a typical UBA domain fold of three tightly packed α-helices but with an additional N-terminal 310 helix. The XIAP-UBA binds mono-ubiquitin as well as Lys48-linked and linear-linked diubiquitins at low-micromolar affinities. NMR analysis of the XIAP-UBA–ubiquitin interaction reveals that it involves the classical hydrophobic patches surrounding Ile44 of ubiquitin and the conserved MGF/LV motif surfaces on XIAP-UBA. Furthermore, dimerization of XIAP-UBA was observed. Mapping of the self-association surface of XIAP-UBA reveals that the dimerization interface is formed by residues in the N-terminal 310 helix, helix α1 and helix α2, separate from the ubiquitin-binding surface. Conclusion Our results provide the first structural information of XIAP-UBA and map its interaction with mono-ubiquitin, Lys48-linked and linear-linked diubiquitins. The notion that XIAP-UBA uses different surfaces for ubiquitin-binding and self-association provides a plausible model to explain the reported selectivity of XIAP in binding polyubiquitin chains with different linkages.
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Affiliation(s)
- Man Kit Tse
- Department of Microbiology and State Key Laboratory for Emerging Infectious Diseases, The University of Hong Kong, Hong Kong SAR, People's Republic of China
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31
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Castañeda CA, Spasser L, Bavikar SN, Brik A, Fushman D. Segmental Isotopic Labeling of Ubiquitin Chains To Unravel Monomer-Specific Molecular Behavior. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201104649] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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32
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Castañeda CA, Spasser L, Bavikar SN, Brik A, Fushman D. Segmental isotopic labeling of ubiquitin chains to unravel monomer-specific molecular behavior. Angew Chem Int Ed Engl 2011; 50:11210-4. [PMID: 21957015 DOI: 10.1002/anie.201104649] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Revised: 08/15/2011] [Indexed: 12/14/2022]
Affiliation(s)
- Carlos A Castañeda
- Department of Chemistry and Biochemistry, Center for Biomolecular Structure and Organization, University of Maryland, College Park, MD 20742, USA
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33
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Wilson RC, Edmondson SP, Flatt JW, Helms K, Twigg PD. The E2-25K ubiquitin-associated (UBA) domain aids in polyubiquitin chain synthesis and linkage specificity. Biochem Biophys Res Commun 2011; 405:662-6. [PMID: 21281599 DOI: 10.1016/j.bbrc.2011.01.089] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Accepted: 01/25/2011] [Indexed: 11/18/2022]
Abstract
E2-25K is an ubiquitin-conjugating enzyme with the ability to synthesize Lys48-linked polyubiquitin chains. E2-25K and its homologs represent the only known E2 enzymes which contain a C-terminal ubiquitin-associated (UBA) domain as well as the conserved catalytic ubiquitin-conjugating (UBC) domain. As an additional non-covalent binding surface for ubiquitin, the UBA domain must provide some functional specialization. We mapped the protein-protein interface involved in the E2-25K UBA/ubiquitin complex by solution nuclear magnetic resonance (NMR) spectroscopy and subsequently modeled the structure of the complex. Domain-domain interactions between the E2-25K catalytic UBC domain and the UBA domain do not induce significant structural changes in the UBA domain or alter the affinity of the UBA domain for ubiquitin. We determined that one of the roles of the C-terminal UBA domain, in the context of E2-25K, is to increase processivity in Lys48-linked polyubiquitin chain synthesis, possibly through increased binding to the ubiquitinated substrate. Additionally, we see evidence that the UBA domain directs specificity in polyubiquitin chain linkage.
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Affiliation(s)
- Randall C Wilson
- Laboratory for Structural Biology, University of Alabama in Huntsville, Huntsville, AL 35899, USA
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34
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Song AX, Zhou CJ, Peng Y, Gao XC, Zhou ZR, Fu QS, Hong J, Lin DH, Hu HY. Structural transformation of the tandem ubiquitin-interacting motifs in ataxin-3 and their cooperative interactions with ubiquitin chains. PLoS One 2010; 5:e13202. [PMID: 20949063 PMCID: PMC2951365 DOI: 10.1371/journal.pone.0013202] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2010] [Accepted: 09/03/2010] [Indexed: 11/18/2022] Open
Abstract
The ubiquitin-interacting motif (UIM) is a short peptide with dual function of binding ubiquitin (Ub) and promoting ubiquitination. We elucidated the structures and dynamics of the tandem UIMs of ataxin-3 (AT3-UIM12) both in free and Ub-bound forms. The solution structure of free AT3-UIM12 consists of two α-helices and a flexible linker, whereas that of the Ub-bound form is much more compact with hydrophobic contacts between the two helices. NMR dynamics indicates that the flexible linker becomes rigid when AT3-UIM12 binds with Ub. Isothermal titration calorimetry and NMR titration demonstrate that AT3-UIM12 binds diUb with two distinct affinities, and the linker plays a critical role in association of the two helices in diUb binding. These results provide an implication that the tandem UIM12 interacts with Ub or diUb in a cooperative manner through an allosteric effect and dynamics change of the linker region, which might be related to its recognitions with various Ub chains and ubiquitinated substrates.
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Affiliation(s)
- Ai-Xin Song
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Chen-Jie Zhou
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Yu Peng
- Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Xue-Chao Gao
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Zi-Ren Zhou
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Qing-Shan Fu
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Jing Hong
- Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Dong-Hai Lin
- Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
- * E-mail: (H-YH); (D-HL)
| | - Hong-Yu Hu
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
- * E-mail: (H-YH); (D-HL)
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35
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Gautheron J, Courtois G. "Without Ub I am nothing": NEMO as a multifunctional player in ubiquitin-mediated control of NF-kappaB activation. Cell Mol Life Sci 2010; 67:3101-13. [PMID: 20502939 PMCID: PMC11115954 DOI: 10.1007/s00018-010-0404-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2010] [Revised: 05/06/2010] [Accepted: 05/07/2010] [Indexed: 11/26/2022]
Abstract
Ubiquitination has emerged over the years as the most sophisticated way to modify proteins to affect their fate and function. In particular, it has been reported to be instrumental in regulating several steps of the NF-kappaB signalling pathway which controls inflammation, immunity, adhesion and cell survival. Integrating ubiquitination into NF-kappaB activation requires the regulatory subunit of IKK, NEMO, which not only displays affinity for polyubiquitin chains, but is also posttranslationally modified by a complex set of reactions involving ubiquitin. Here, we examine how studies of the NEMO/ubiquitin relationship have provided novel insights into the IKK activation process and have uncovered molecular mechanisms that should represent in the future attractive targets for specifically modulating NF-kappaB function.
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Affiliation(s)
- Jérémie Gautheron
- INSERM U781, Tour Lavoisier, Hôpital Necker-Enfants Malades and Université Paris-Descartes, 149, rue de Sèvres, 75015 Paris, France
| | - Gilles Courtois
- INSERM U781, Tour Lavoisier, Hôpital Necker-Enfants Malades and Université Paris-Descartes, 149, rue de Sèvres, 75015 Paris, France
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36
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Song AX, Zhou CJ, Guan X, Sze KH, Hu HY. Solution structure of the N-terminal domain of DC-UbP/UBTD2 and its interaction with ubiquitin. Protein Sci 2010; 19:1104-9. [PMID: 20440844 DOI: 10.1002/pro.386] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
DC-UbP/UBTD2 is a ubiquitin (Ub) domain-containing protein first identified from dendritic cells, and is implicated in ubiquitination pathway. The solution structure and backbone dynamics of the C-terminal Ub-like (UbL) domain were elucidated in our previous work. To further understand the biological function of DC-UbP, we then solved the solution structure of the N-terminal domain of DC-UbP (DC-UbP_N) and studied its Ub binding properties by NMR techniques. The results show that DC-UbP_N holds a novel structural fold and acts as a Ub-binding domain (UBD) but with low affinity. This implies that the DC-UbP protein, composing of a combination of both UbL and UBD domains, might play an important role in regulating protein ubiquitination and delivery of ubiquitinated substrates in eukaryotic cells.
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Affiliation(s)
- Ai-Xin Song
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
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37
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Wooten MW, Hu X, Babu JR, Seibenhener ML, Geetha T, Paine MG, Wooten MC. Signaling, polyubiquitination, trafficking, and inclusions: sequestosome 1/p62's role in neurodegenerative disease. J Biomed Biotechnol 2010; 2006:62079. [PMID: 17047309 PMCID: PMC1559922 DOI: 10.1155/jbb/2006/62079] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Aggregated misfolded proteins are hallmarks of most neurodegenerative diseases. In a chronic disease state, including pathologic
situations of oxidative stress, these proteins are sequestered into inclusions. Accumulation of aggregated proteins can be
prevented by chaperones, or by targeting their degradation to the UPS. If the accumulation of these proteins exceeds their
degradation, they may impair the function of the proteasome. Alternatively, the function of the proteasome may be preserved
by directing aggregated proteins to the autophagy-lysosome pathway for degradation. Sequestosome 1/p62 has recently been
shown to interact with polyubiquitinated proteins through its UBA domain and may direct proteins to either the UPS or autophagosome.
P62 is present in neuronal inclusions of individuals with Alzheimer's disease and other neurodegenerative diseases.
Herein, we review p62's role in signaling, aggregation, and inclusion formation, and specifically as a possible contributor
to Alzheimer's disease. The use of p62 as a potential target for the development of therapeutics and as a disease biomarker is also discussed.
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Affiliation(s)
- Marie W. Wooten
- Program in Cell & Molecular Biosciences, Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA
| | - Xiao Hu
- Program in Cell & Molecular Biosciences, Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA
| | - J. Ramesh Babu
- Program in Cell & Molecular Biosciences, Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA
| | - M. Lamar Seibenhener
- Program in Cell & Molecular Biosciences, Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA
- *M. Lamar Seibenhener:
| | - Thangiah Geetha
- Program in Cell & Molecular Biosciences, Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA
| | - Michael G. Paine
- Program in Cell & Molecular Biosciences, Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA
| | - Michael C. Wooten
- Program in Cell & Molecular Biosciences, Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA
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38
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Song J, Park JK, Lee JJ, Choi YS, Ryu KS, Kim JH, Kim E, Lee KJ, Jeon YH, Kim EE. Structure and interaction of ubiquitin-associated domain of human Fas-associated factor 1. Protein Sci 2010; 18:2265-76. [PMID: 19722279 DOI: 10.1002/pro.237] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Fas-associated factor (FAF)-1 is a multidomain protein that was first identified as a member of the Fas death-inducing signaling complex, but later found to be involved in various biological processes. Although the exact mechanisms are not clear, FAF1 seems to play an important role in cancer, asbestos-induced mesotheliomas, and Parkinson's disease. It interacts with polyubiquitinated proteins, Hsp70, and p97/VCP (valosin-containing protein), in addition to the proteins of the Fas-signaling pathway. We have determined the crystal structure of the ubiquitin-associated domain of human FAF1 (hFAF1-UBA) and examined its interaction with ubiquitin and ubiquitin-like proteins using nuclear magnetic resonance. hFAF1-UBA revealed a canonical three-helical bundle that selectively binds to mono- and di-ubiquitin (Lys48-linked), but not to SUMO-1 (small ubiquitin-related modifier 1) or NEDD8 (neural precursor cell expressed, developmentally down-regulated 8). The interaction between hFAF1-UBA and di-ubiquitin involves hydrophobic interaction accompanied by a transition in the di-ubiquitin conformation. These results provide structural insight into the mechanism of polyubiquitin recognition by hFAF1-UBA.
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Affiliation(s)
- Jinsue Song
- Magnetic Resonance Team, Korea Basic Science Institute, 804-1 Yangchung-Ri, Ochang, Chungbuk, Korea
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39
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Zhang D, Chen T, Ziv I, Rosenzweig R, Matiuhin Y, Bronner V, Glickman MH, Fushman D. Together, Rpn10 and Dsk2 can serve as a polyubiquitin chain-length sensor. Mol Cell 2010; 36:1018-33. [PMID: 20064467 DOI: 10.1016/j.molcel.2009.11.012] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2009] [Revised: 08/24/2009] [Accepted: 10/21/2009] [Indexed: 11/17/2022]
Abstract
As a signal for substrate targeting, polyubiquitin meets various layers of receptors upstream to the 26S proteasome. We obtained structural information on two receptors, Rpn10 and Dsk2, alone and in complex with (poly)ubiquitin or with each other. A hierarchy of affinities emerges with Dsk2 binding monoubiquitin tighter than Rpn10 does, whereas Rpn10 prefers the ubiquitin-like domain of Dsk2 to monoubiquitin, with increasing affinities for longer polyubiquitin chains. We demonstrated the formation of ternary complexes of both receptors simultaneously with (poly)ubiquitin and found that, depending on the ubiquitin chain length, the orientation of the resulting complex is entirely different, providing for alternate signals. Dynamic rearrangement provides a chain-length sensor, possibly explaining how accessibility of Dsk2 to the proteasome is limited unless it carries a properly tagged cargo. We propose a mechanism for a malleable ubiquitin signal that depends both on chain length and combination of receptors to produce tetraubiquitin as an efficient signal threshold.
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Affiliation(s)
- Daoning Zhang
- Department of Chemistry and Biochemistry, Center for Biomolecular Structure and Organization, University of Maryland, College Park, 20910, USA
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40
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Ubiquitin-like and ubiquitin-associated domain proteins: significance in proteasomal degradation. Cell Mol Life Sci 2009; 66:2819-33. [PMID: 19468686 DOI: 10.1007/s00018-009-0048-9] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2009] [Revised: 04/14/2009] [Accepted: 04/29/2009] [Indexed: 10/20/2022]
Abstract
The ubiquitin-proteasome pathway of protein degradation is one of the major mechanisms that are involved in the maintenance of the proper levels of cellular proteins. The regulation of proteasomal degradation thus ensures proper cell functions. The family of proteins containing ubiquitin-like (UbL) and ubiquitin-associated (UBA) domains has been implicated in proteasomal degradation. UbL-UBA domain containing proteins associate with substrates destined for degradation as well as with subunits of the proteasome, thus regulating the proper turnover of proteins.
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41
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Dantuma NP, Heinen C, Hoogstraten D. The ubiquitin receptor Rad23: at the crossroads of nucleotide excision repair and proteasomal degradation. DNA Repair (Amst) 2009; 8:449-60. [PMID: 19223247 DOI: 10.1016/j.dnarep.2009.01.005] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A protein that exemplifies the intimate link between the ubiquitin/proteasome system (UPS) and DNA repair is the yeast nucleotide excision repair (NER) protein Rad23 and its human orthologs hHR23A and hHR23B. Rad23, which was originally identified as an important factor involved in the recognition of DNA lesions, also plays a central role in targeting ubiquitylated proteins for proteasomal degradation, an activity that it shares with other ubiquitin receptors like Dsk2 and Ddi1. Although the finding that Rad23 serves as a ubiquitin receptor explains to a large extent its importance in proteasomal degradation, the precise mode of action of Rad23 in NER and the possible link with the UPS is less clear. In this review, we discuss our present knowledge on the functions of Rad23 in protein degradation and DNA repair and speculate on the importance of the dual roles of Rad23 for the cell's ability to cope with stress conditions.
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Affiliation(s)
- Nico P Dantuma
- Department of Cell and Molecular Biology, The Medical Nobel Institute, Karolinska Institutet, Von Eulers väg 3, S-17177 Stockholm, Sweden.
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Matta-Camacho E, Kozlov G, Trempe JF, Gehring K. Atypical Binding of the Swa2p UBA Domain to Ubiquitin. J Mol Biol 2009; 386:569-77. [DOI: 10.1016/j.jmb.2008.09.086] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2008] [Revised: 09/30/2008] [Accepted: 09/30/2008] [Indexed: 10/21/2022]
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Hong YH, Ahn HC, Lim J, Kim HM, Ji HY, Lee S, Kim JH, Park EY, Song HK, Lee BJ. Identification of a novel ubiquitin binding site of STAM1 VHS domain by NMR spectroscopy. FEBS Lett 2008; 583:287-92. [PMID: 19111546 DOI: 10.1016/j.febslet.2008.12.034] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2008] [Revised: 12/12/2008] [Accepted: 12/12/2008] [Indexed: 11/27/2022]
Abstract
Interaction between the signal-transducing adapter molecule 1 (STAM1) Vps27/Hrs/Stam (VHS) domain and ubiquitin was investigated by nuclear magnetic resonance (NMR) spectroscopy. NMR evidence showed that the structure of STAM1 VHS domain resembles that of other VHS domains, especially the homologous domain of STAM2. We found that the VHS domain binds to ubiquitin via its hydrophobic patch consisting of N-terminus of helix 2 and C-terminus of helix 4 in which Trp26 on helix 2 plays a pivotal role in the binding. The binding between VHS and ubiquitin seems to be very similar to that between ubiquitin associated domain (UBA) and ubiquitin, however, the direction of alpha-helices involved in the ubiquitin binding is opposite. Here, we propose a novel ubiquitin binding site and the manner of ubiquitin recognition of the STAM1 VHS domain.
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Affiliation(s)
- Yoon-Hun Hong
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, San 56-1, Shillim-dong, Kwanak-gu, Seoul 151-742, Republic of Korea
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Ribosome association and stability of the nascent polypeptide-associated complex is dependent upon its own ubiquitination. Genetics 2008; 181:447-60. [PMID: 19087962 DOI: 10.1534/genetics.108.095422] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In this work we addressed the role of ubiquitination in the function of the nascent polypeptide-associated complex (NAC), named EGD in the yeast Saccharomyces cerevisiae. To this end, we first identified the lysines residues required for ubiquitination of EGD/NAC. While simultaneous mutation of many lysines in the alpha-subunit of NAC (Egd2p) was required to abolish its ubiquitination, for the beta-subunit of NAC (Egd1p), mutation of K29 and K30 was sufficient. We determined that the ubiquitination of the two EGD subunits was coordinated, occurring during growth first on Egd1p and then on Egd2p. Egd2p was ubiquitinated earlier during growth if Egd1p could not be ubiquitinated. The use of mutants revealed the importance of EGD ubiqutination for its ribosome association and stability. Finally, our study demonstrated an interaction of EGD/NAC with the proteasome and revealed the importance of the Not4p E3 ligase, responsible for EGD/NAC ubiquitination, in this association.
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Kang J, Kang S, Kwon HN, He W, Park S. Distinct interactions between ubiquitin and the SH3 domains involved in immune signaling. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2008; 1784:1335-41. [DOI: 10.1016/j.bbapap.2008.04.031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2008] [Revised: 04/07/2008] [Accepted: 04/26/2008] [Indexed: 11/16/2022]
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Abstract
Ubiquitin is a highly conserved 76-amino acid polypeptide that is found throughout the eukaryotic kingdom. The covalent conjugation of ubiquitin (often in the form of a polymer) to substrates governs a variety of biological processes ranging from proteolysis to DNA damage tolerance. The functional flexibility of this post-translational modification has its roots in the existence of a large number of ubiquitinating enzymes that catalyze the formation of distinct ubiquitin polymers, which in turn encode different signals. This review summarizes recent advances in the field with an emphasis on the non-canonical functions of polyubiquitination. We also discuss the potential mechanism of chain linkage specification as well as how structural disparity in ubiquitin polymers may be distinguished by ubiquitin receptors to translate the versatile ubiquitin signals into various cellular functions.
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Affiliation(s)
- W. Li
- Building 5, Room 433, Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 5 center drive, Bethesda, MD 20892 USA
| | - Y. Ye
- Building 5, Room 433, Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 5 center drive, Bethesda, MD 20892 USA
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Reyes-Turcu FE, Shanks JR, Komander D, Wilkinson KD. Recognition of polyubiquitin isoforms by the multiple ubiquitin binding modules of isopeptidase T. J Biol Chem 2008; 283:19581-92. [PMID: 18482987 DOI: 10.1074/jbc.m800947200] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The conjugation of polyubiquitin to target proteins acts as a signal that regulates target stability, localization, and function. Several ubiquitin binding domains have been described, and while much is known about ubiquitin binding to the isolated domains, little is known with regard to how the domains interact with polyubiquitin in the context of full-length proteins. Isopeptidase T (IsoT/USP5) is a deubiquitinating enzyme that is largely responsible for the disassembly of unanchored polyubiquitin in the cell. IsoT has four ubiquitin binding domains: a zinc finger domain (ZnF UBP), which binds the proximal ubiquitin, a UBP domain that forms the active site, and two ubiquitin-associated (UBA) domains whose roles are unknown. Here, we show that the UBA domains are involved in binding two different polyubiquitin isoforms, linear and K48-linked. Using isothermal titration calorimetry, we show that IsoT has at least four ubiquitin binding sites for both polyubiquitin isoforms. The thermodynamics of the interactions reveal that the binding is enthalpy-driven. Mutation of the UBA domains suggests that UBA1 and UBA2 domains of IsoT interact with the third and fourth ubiquitins in both polyubiquitin isoforms, respectively. These data suggest that recognition of the polyubiquitin isoforms by IsoT involves considerable conformational mobility in the polyubiquitin ligand, in the enzyme, or in both.
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Affiliation(s)
- Francisca E Reyes-Turcu
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia 30322, USA
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Evans CL, Long JE, Gallagher TRA, Hirst JD, Searle MS. Conformation and dynamics of the three-helix bundle UBA domain of p62 from experiment and simulation. Proteins 2008; 71:227-40. [PMID: 17932931 DOI: 10.1002/prot.21692] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The ubiquitin associated domain of p62 is a small three-helix bundle of approximately 50 residues that mediates the recognition of polyubiquitin chains and ubiquitylated substrates. The solution structure of a 52 residue construct containing this domain has been characterized using heteronuclear nuclear magnetic resonance (NMR) methods. The resulting ensemble of NMR-derived structures was used in molecular dynamics (MD) simulations to investigate the equilibrium conformation and dynamics of this domain. NOE and (15)N relaxation data have been used to validate the structural ensemble produced by the MD simulations and show a good correlation for residues in regions of secondary structure. A similar approach was taken using an ensemble of structures from the MD simulations to calculate electronic circular dichroism (CD) and IR spectra from first principles with an encouraging correlation with the experimental CD and IR data.
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Affiliation(s)
- Clare-Louise Evans
- School of Chemistry, University Park, University of Nottingham, Nottingham NG7 2RD, United Kingdom
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Tong Y, Hota PK, Hamaneh MB, Buck M. Insights into oncogenic mutations of plexin-B1 based on the solution structure of the Rho GTPase binding domain. Structure 2008; 16:246-58. [PMID: 18275816 PMCID: PMC2358926 DOI: 10.1016/j.str.2007.12.012] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2007] [Revised: 11/19/2007] [Accepted: 12/06/2007] [Indexed: 10/22/2022]
Abstract
The plexin family of transmembrane receptors are important for axon guidance, angiogenesis, but also in cancer. Recently, plexin-B1 somatic missense mutations were found in both primary tumors and metastases of breast and prostate cancers, with several mutations mapping to the Rho GTPase binding domain (RBD) in the cytoplasmic region of the receptor. Here we present the NMR solution structure of this domain, confirming that the protein has both a ubiquitin-like fold and surface features. Oncogenic mutations T1795A and T1802A are located in a loop region, perturb the average structure locally, and have no effect on Rho GTPase binding affinity. Mutations L1815F and L1815P are located at the Rho GTPase binding site and are associated with a complete loss of binding for Rac1 and Rnd1. Both are found to disturb the conformation of the beta3-beta4 sheet and the orientation of surrounding side chains. Our study suggests that the oncogenic behavior of the mutants can be rationalized with reference to the structure of the RBD of plexin-B1.
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Affiliation(s)
- Yufeng Tong
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, 10900 Euclid Avenue, Cleveland, Ohio 44106, USA
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Goh AM, Walters KJ, Elsasser S, Verma R, Deshaies RJ, Finley D, Howley PM. Components of the ubiquitin-proteasome pathway compete for surfaces on Rad23 family proteins. BMC BIOCHEMISTRY 2008; 9:4. [PMID: 18234089 PMCID: PMC2267792 DOI: 10.1186/1471-2091-9-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2007] [Accepted: 01/30/2008] [Indexed: 12/03/2022]
Abstract
Background The delivery of ubiquitinated proteins to the proteasome for degradation is a key step in the regulation of the ubiquitin-proteasome pathway, yet the mechanisms underlying this step are not understood in detail. The Rad23 family of proteins is known to bind ubiquitinated proteins through its two ubiquitin-associated (UBA) domains, and may participate in the delivery of ubiquitinated proteins to the proteasome through docking via the Rad23 ubiquitin-like (UBL) domain. Results In this study, we investigate how the interaction between the UBL and UBA domains may modulate ubiquitin recognition and the delivery of ubiquitinated proteins to the proteasome by autoinhibition. We have explored a competitive binding model using specific mutations in the UBL domain. Disrupting the intramolecular UBL-UBA domain interactions in HHR23A indeed potentiates ubiquitin-binding. Additionally, the analogous surface on the Rad23 UBL domain overlaps with that required for interaction with both proteasomes and the ubiquitin ligase Ufd2. We have found that mutation of residues on this surface affects the ability of Rad23 to deliver ubiquitinated proteins to the proteasome. Conclusion We conclude that the competition of ubiquitin-proteasome pathway components for surfaces on Rad23 is important for the role of the Rad23 family proteins in proteasomal targeting.
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Affiliation(s)
- Amanda M Goh
- Department of Pathology, Harvard Medical School, Boston, Massachusetts, USA.
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