1
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Hicks CW, Rahman S, Gloor SL, Fields JK, Husby NL, Vaidya A, Maier KE, Morgan M, Keogh MC, Wolberger C. Ubiquitinated histone H2B as gatekeeper of the nucleosome acidic patch. Nucleic Acids Res 2024; 52:9978-9995. [PMID: 39149911 PMCID: PMC11381367 DOI: 10.1093/nar/gkae698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 07/15/2024] [Accepted: 08/01/2024] [Indexed: 08/17/2024] Open
Abstract
Monoubiquitination of histones H2B-K120 (H2BK120ub) and H2A-K119 (H2AK119ub) play opposing roles in regulating transcription and chromatin compaction. H2BK120ub is a hallmark of actively transcribed euchromatin, while H2AK119ub is highly enriched in transcriptionally repressed heterochromatin. Whereas H2BK120ub is known to stimulate the binding or activity of various chromatin-modifying enzymes, this post-translational modification (PTM) also interferes with the binding of several proteins to the nucleosome H2A/H2B acidic patch via an unknown mechanism. Here, we report cryoEM structures of an H2BK120ub nucleosome showing that ubiquitin adopts discrete positions that occlude the acidic patch. Molecular dynamics simulations show that ubiquitin remains stably positioned over this nucleosome region. By contrast, our cryoEM structures of H2AK119ub nucleosomes show ubiquitin adopting discrete positions that minimally occlude the acidic patch. Consistent with these observations, H2BK120ub, but not H2AK119ub, abrogates nucleosome interactions with acidic patch-binding proteins RCC1 and LANA, and single-domain antibodies specific to this region. Our results suggest a mechanism by which H2BK120ub serves as a gatekeeper to the acidic patch and point to distinct roles for histone H2AK119 and H2BK120 ubiquitination in regulating protein binding to nucleosomes.
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Affiliation(s)
- Chad W Hicks
- Department of Biophysics & Biophysical Chemistry, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205, USA
| | - Sanim Rahman
- Department of Biophysics & Biophysical Chemistry, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205, USA
| | - Susan L Gloor
- EpiCypher Inc., 6 Davis Drive, Suite 755, Durham, NC 27709, USA
| | - James K Fields
- Department of Biophysics & Biophysical Chemistry, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205, USA
| | | | - Anup Vaidya
- EpiCypher Inc., 6 Davis Drive, Suite 755, Durham, NC 27709, USA
| | - Keith E Maier
- EpiCypher Inc., 6 Davis Drive, Suite 755, Durham, NC 27709, USA
| | - Michael Morgan
- Department of Biophysics & Biophysical Chemistry, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205, USA
| | | | - Cynthia Wolberger
- Department of Biophysics & Biophysical Chemistry, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205, USA
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2
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Cannea FB, Diana D, Rossino R, Padiglia A. ECPUB5 Polyubiquitin Gene in Euphorbia characias: Molecular Characterization and Seasonal Expression Analysis. Genes (Basel) 2024; 15:957. [PMID: 39062736 PMCID: PMC11275293 DOI: 10.3390/genes15070957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2024] [Revised: 07/17/2024] [Accepted: 07/18/2024] [Indexed: 07/28/2024] Open
Abstract
The spurge Euphorbia characias is known for its latex, which is rich in antioxidant enzymes and anti-phytopathogen molecules. In this study, we identified a novel polyubiquitin protein in the latex and leaves, leading to the first molecular characterization of its coding gene and expressed protein in E. characias. Using consensus-degenerate hybrid oligonucleotide primers (CODEHOP) and rapid amplification of cDNA ends (5'/3'-RACE), we reconstructed the entire open reading frame (ORF) and noncoding regions. Our analysis revealed that the polyubiquitin gene encodes five tandemly repeated sequences, each coding for a ubiquitin monomer with amino acid variations in four of the five repeats. In silico studies have suggested functional differences among monomers. Gene expression peaked during the summer, correlating with high temperatures and suggesting a role in heat stress response. Western blotting confirmed the presence of polyubiquitin in the latex and leaf tissues, indicating active ubiquitination processes. These findings enhance our understanding of polyubiquitin's regulatory mechanisms and functions in E. characias, highlighting its unique structural and functional features.
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Affiliation(s)
- Faustina Barbara Cannea
- Biomedical Section, Department of Life and Environmental Sciences (DiSVA), Cittadella Universitaria di Monserrato, University of Cagliari, 09042 Cagliari, Italy;
| | - Daniela Diana
- Department of Medical Sciences and Public Health (DSMSP), AOU Presidio Microcitemico, University of Cagliari, 09121 Cagliari, Italy; (D.D.); (R.R.)
| | - Rossano Rossino
- Department of Medical Sciences and Public Health (DSMSP), AOU Presidio Microcitemico, University of Cagliari, 09121 Cagliari, Italy; (D.D.); (R.R.)
| | - Alessandra Padiglia
- Biomedical Section, Department of Life and Environmental Sciences (DiSVA), Cittadella Universitaria di Monserrato, University of Cagliari, 09042 Cagliari, Italy;
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3
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Shadman H, Ziebarth JD, Gallops CE, Luo R, Li Z, Chen HF, Wang Y. Map conformational landscapes of intrinsically disordered proteins with polymer physics quantities. Biophys J 2024; 123:1253-1263. [PMID: 38615193 PMCID: PMC11140466 DOI: 10.1016/j.bpj.2024.04.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 02/20/2024] [Accepted: 04/10/2024] [Indexed: 04/15/2024] Open
Abstract
Disordered proteins are conformationally flexible proteins that are biologically important and have been implicated in devastating diseases such as Alzheimer's disease and cancer. Unlike stably folded structured proteins, disordered proteins sample a range of different conformations that needs to be accounted for. Here, we treat disordered proteins as polymer chains, and compute a dimensionless quantity called instantaneous shape ratio (Rs), as Rs = Ree2/Rg2, where Ree is end-to-end distance and Rg is radius of gyration. Extended protein conformations tend to have high Ree compared with Rg, and thus have high Rs values, whereas compact conformations have smaller Rs values. We use a scatter plot of Rs (representing shape) against Rg (representing size) as a simple map of conformational landscapes. We first examine the conformational landscape of simple polymer models such as Random Walk, Self-Avoiding Walk, and Gaussian Walk (GW), and we notice that all protein/polymer maps lie within the boundaries of the GW map. We thus use the GW map as a reference and, to assess conformational diversity, we compute the fraction of the GW conformations (fC) covered by each protein/polymer. Disordered proteins all have high fC scores, consistent with their disordered nature. Each disordered protein accesses a different region of the reference map, revealing differences in their conformational ensembles. We additionally examine the conformational maps of the nonviral gene delivery vector polyethyleneimine at various protonation states, and find that they resemble disordered proteins, with coverage of the reference map decreasing with increasing protonation state, indicating decreasing conformational diversity. We propose that our method of combining Rs and Rg in a scatter plot generates a simple, meaningful map of the conformational landscape of a disordered protein, which in turn can be used to assess conformational diversity of disordered proteins.
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Affiliation(s)
- Hossain Shadman
- Department of Chemistry, The University of Memphis, Memphis, Tennessee
| | - Jesse D Ziebarth
- Department of Chemistry, The University of Memphis, Memphis, Tennessee
| | - Caleb E Gallops
- Department of Chemistry, The University of Memphis, Memphis, Tennessee
| | - Ray Luo
- Chemical and Materials Physics Graduate Program, Departments of Molecular Biology and Biochemistry, Chemical and Biomolecular Engineering, Materials Science and Engineering, and Biomedical Engineering, University of California, Irvine, Irvine, California
| | - Zhengxin Li
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, Department of Bioinformatics and Biostatistics, National Experimental Teaching Center for Life Sciences and Biotechnology, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Hai-Feng Chen
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, Department of Bioinformatics and Biostatistics, National Experimental Teaching Center for Life Sciences and Biotechnology, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Yongmei Wang
- Department of Chemistry, The University of Memphis, Memphis, Tennessee.
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4
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Hung TI, Hsieh YJ, Lu WL, Wu KP, Chang CEA. What Strengthens Protein-Protein Interactions: Analysis and Applications of Residue Correlation Networks. J Mol Biol 2023; 435:168337. [PMID: 37918563 DOI: 10.1016/j.jmb.2023.168337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 10/13/2023] [Accepted: 10/26/2023] [Indexed: 11/04/2023]
Abstract
Identifying residues critical to protein-protein binding and efficient design of stable and specific protein binders are challenging tasks. Extending beyond the direct contacts in a protein-protein binding interface, our study employs computational modeling to reveal the essential network of residue interactions and dihedral angle correlations critical in protein-protein recognition. We hypothesized that mutating residues exhibiting highly correlated dynamic motion within the interaction network could efficiently optimize protein-protein interactions to create tight and selective protein binders. We tested this hypothesis using the ubiquitin (Ub) and MERS coronaviral papain-like protease (PLpro) complex, since Ub is a central player in multiple cellular functions and PLpro is an antiviral drug target. Our designed ubiquitin variant (UbV) hosting three mutated residues displayed a ∼3,500-fold increase in functional inhibition relative to wild-type Ub. Further optimization of two C-terminal residues within the Ub network resulted in a KD of 1.5 nM and IC50 of 9.7 nM for the five-point Ub mutant, eliciting 27,500-fold and 5,500-fold enhancements in affinity and potency, respectively, as well as improved selectivity, without destabilizing the UbV structure. Our study highlights residue correlation and interaction networks in protein-protein interactions, and introduces an effective approach to design high-affinity protein binders for cell biology research and future therapeutics.
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Affiliation(s)
- Ta I Hung
- Department of Chemistry, University of California, Riverside, United States; Department of Bioengineering, University of California, Riverside, United States
| | - Yun-Jung Hsieh
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan; Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan
| | - Wei-Lin Lu
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Kuen-Phon Wu
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan; Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan.
| | - Chia-En A Chang
- Department of Chemistry, University of California, Riverside, United States.
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5
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Lemma B, Zhang D, Vamisetti GB, Wentz BG, Suga H, Brik A, Lubkowski J, Fushman D. Mechanism of selective recognition of Lys48-linked polyubiquitin by macrocyclic peptide inhibitors of proteasomal degradation. Nat Commun 2023; 14:7212. [PMID: 37938554 PMCID: PMC10632358 DOI: 10.1038/s41467-023-43025-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Accepted: 10/26/2023] [Indexed: 11/09/2023] Open
Abstract
Post-translational modification of proteins with polyubiquitin chains is a critical cellular signaling mechanism in eukaryotes with implications in various cellular states and processes. Unregulated ubiquitin-mediated protein degradation can be detrimental to cellular homeostasis, causing numerous diseases including cancers. Recently, macrocyclic peptides were developed that selectively target long Lysine-48-linked polyubiquitin chains (tetra-ubiquitin) to inhibit ubiquitin-proteasome system, leading to attenuation of tumor growth in vivo. However, structural determinants of the chain length and linkage selectivity by these cyclic peptides remained unclear. Here, we uncover the mechanism underlying cyclic peptide's affinity and binding selectivity by combining X-ray crystallography, solution NMR, and biochemical studies. We found that the peptide engages three consecutive ubiquitins that form a ring around the peptide and determined requirements for preferential selection of a specific trimer moiety in longer polyubiquitin chains. The structural insights gained from this work will guide the development of next-generation cyclic peptides with enhanced anti-cancer activity.
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Affiliation(s)
- Betsegaw Lemma
- Center for Biomolecular Structure and Organization, Department of Chemistry and Biochemistry, University of Maryland, College Park, MD, 20742, USA
| | - Di Zhang
- Center for Structural Biology, Center for Cancer Research, National Cancer Institute, Frederick, MD, 21702, USA
| | - Ganga B Vamisetti
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Haifa, 3200008, Israel
| | - Bryan G Wentz
- Center for Biomolecular Structure and Organization, Department of Chemistry and Biochemistry, University of Maryland, College Park, MD, 20742, USA
| | - Hiroaki Suga
- Department of Chemistry, Graduate School of Science, The University of Tokyo, Bunkyo-ku, 7-3-1 Hongo, Bunkyo, Tokyo, 113-0033, Japan
| | - Ashraf Brik
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Haifa, 3200008, Israel.
| | - Jacek Lubkowski
- Center for Structural Biology, Center for Cancer Research, National Cancer Institute, Frederick, MD, 21702, USA.
| | - David Fushman
- Center for Biomolecular Structure and Organization, Department of Chemistry and Biochemistry, University of Maryland, College Park, MD, 20742, USA.
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6
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Dalhuisen T, Plenderleith LJ, Ursani I, Philip N, Hahn BH, Sharp PM. Unusually Divergent Ubiquitin Genes and Proteins in Plasmodium Species. Genome Biol Evol 2023; 15:evad137. [PMID: 37481258 PMCID: PMC10457151 DOI: 10.1093/gbe/evad137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 06/29/2023] [Accepted: 07/16/2023] [Indexed: 07/24/2023] Open
Abstract
Ubiquitin is an extraordinarily highly conserved 76 amino acid protein encoded by three different types of gene, where the primary translation products are fusions either of ubiquitin with one of two ribosomal proteins (RPs) or of multiple ubiquitin monomers from head to tail. Here, we investigate the evolution of ubiquitin genes in mammalian malaria parasites (Plasmodium species). The ubiquitin encoded by the RPS27a fusion gene is highly divergent, as previously found in a variety of protists. However, we also find that two other forms of divergent ubiquitin sequence, each previously thought to be extremely rare, have arisen recently during the divergence of Plasmodium subgenera. On two occasions, in two distinct lineages, the ubiquitin encoded by the RPL40 fusion gene has rapidly diverged. In addition, in one of these lineages, the polyubiquitin genes have undergone a single codon insertion, previously considered a unique feature of Rhizaria. There has been disagreement whether the multiple ubiquitin coding repeats within a genome exhibit concerted evolution or undergo a birth-and-death process; the Plasmodium ubiquitin genes show clear signs of concerted evolution, including the spread of this codon insertion to multiple repeats within the polyubiquitin gene.
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Affiliation(s)
- Thomas Dalhuisen
- Institute of Ecology and Evolution, University of Edinburgh, Edinburgh, United Kingdom
- Centre for Immunity, Infection and Evolution, University of Edinburgh, Edinburgh, United Kingdom
| | - Lindsey J Plenderleith
- Institute of Ecology and Evolution, University of Edinburgh, Edinburgh, United Kingdom
- Centre for Immunity, Infection and Evolution, University of Edinburgh, Edinburgh, United Kingdom
| | - Ismail Ursani
- Institute of Ecology and Evolution, University of Edinburgh, Edinburgh, United Kingdom
- Centre for Immunity, Infection and Evolution, University of Edinburgh, Edinburgh, United Kingdom
| | - Nisha Philip
- Institute of Immunology and Infection Research, University of Edinburgh, Edinburgh, United Kingdom
| | - Beatrice H Hahn
- Departments of Medicine and Microbiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Paul M Sharp
- Institute of Ecology and Evolution, University of Edinburgh, Edinburgh, United Kingdom
- Centre for Immunity, Infection and Evolution, University of Edinburgh, Edinburgh, United Kingdom
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7
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Hou XN, Tang C. The pros and cons of ubiquitination on the formation of protein condensates. Acta Biochim Biophys Sin (Shanghai) 2023; 55:1084-1098. [PMID: 37294105 PMCID: PMC10423694 DOI: 10.3724/abbs.2023096] [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: 12/30/2022] [Accepted: 03/19/2023] [Indexed: 06/10/2023] Open
Abstract
Ubiquitination, a post-translational modification that attaches one or more ubiquitin (Ub) molecules to another protein, plays a crucial role in the phase-separation processes. Ubiquitination can modulate the formation of membrane-less organelles in two ways. First, a scaffold protein drives phase separation, and Ub is recruited to the condensates. Second, Ub actively phase-separates through the interactions with other proteins. Thus, the role of ubiquitination and the resulting polyUb chains ranges from bystanders to active participants in phase separation. Moreover, long polyUb chains may be the primary driving force for phase separation. We further discuss that the different roles can be determined by the lengths and linkages of polyUb chains which provide preorganized and multivalent binding platforms for other client proteins. Together, ubiquitination adds a new layer of regulation for the flow of material and information upon cellular compartmentalization of proteins.
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Affiliation(s)
- Xue-Ni Hou
- Beijing National Laboratory for Molecular SciencesCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing100871China
| | - Chun Tang
- Beijing National Laboratory for Molecular SciencesCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing100871China
- Center for Quantitate BiologyPKU-Tsinghua Center for Life ScienceAcademy for Advanced Interdisciplinary StudiesPeking UniversityBeijing100871China
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8
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Hung TI, Hsieh YJ, Lu WL, Wu KP, Chang CEA. What Strengthens Protein-Protein Interactions: Analysis and Applications of Residue Correlation Networks. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.15.532709. [PMID: 36993448 PMCID: PMC10055079 DOI: 10.1101/2023.03.15.532709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
Identifying critical residues in protein-protein binding and efficiently designing stable and specific protein binders is challenging. In addition to direct contacts in a protein-protein binding interface, our study employs computation modeling to reveal the essential network of residue interaction and dihedral angle correlation critical in protein-protein recognition. We propose that mutating residues regions exhibited highly correlated motions within the interaction network can efficiently optimize protein-protein interactions to create tight and selective protein binders. We validated our strategy using ubiquitin (Ub) and MERS coronaviral papain-like protease (PLpro) complexes, where Ub is one central player in many cellular functions and PLpro is an antiviral drug target. Our designed UbV with 3 mutated residues resulted in a ~3,500-fold increase in functional inhibition, compared with the wild-type Ub. Further optimization by incorporating 2 more residues within the network, the 5-point mutant achieved a KD of 1.5 nM and IC50 of 9.7 nM. The modification led to a 27,500-fold and 5,500-fold enhancements in affinity and potency, respectively, as well as improved selectivity, without destabilizing the UbV structure. Our study highlights residue correlation and interaction networks in protein-protein interaction, introduces an effective approach to design high affinity protein binders for cell biology and future therapeutics solutions.
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Affiliation(s)
- Ta I Hung
- Department of Chemistry, University of California, Riverside, United States
- Department of Bioengineering, University of California, Riverside, United States
| | - Yun-Jung Hsieh
- Institute of Biological Chemistry, Academia Sinica, Taiwan
- Institute of Biochemical Sciences, National Taiwan University, Taiwan
| | - Wei-Lin Lu
- Institute of Biological Chemistry, Academia Sinica, Taiwan
| | - Kuen-Phon Wu
- Institute of Biological Chemistry, Academia Sinica, Taiwan
- Institute of Biochemical Sciences, National Taiwan University, Taiwan
| | - Chia-en A. Chang
- Department of Chemistry, University of California, Riverside, United States
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9
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Chong SH, Ham S. Evolutionary conservation of amino acids contributing to the protein folding transition state. J Comput Chem 2023; 44:1002-1009. [PMID: 36571461 DOI: 10.1002/jcc.27060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 11/22/2022] [Accepted: 12/06/2022] [Indexed: 12/27/2022]
Abstract
The question of whether amino acids critical to protein folding kinetics are evolutionarily conserved has been investigated intensively in the past, but no consensus has yet been reached. Recently, we have demonstrated that the transition state, dictating folding kinetics, is characterized as the state of maximum dynamic cooperativity, i.e., the state of maximum correlations between amino acid contact formations. Here, we investigate the evolutionary conservation of those amino acids contributing significantly to the dynamic cooperativity. We find a strong indication of a new kind of relationship-necessary but not sufficient causality-between the evolutionary conservation and the dynamic cooperativity: larger contributions to the dynamic cooperativity arise from more conserved residues, but not vice versa. This holds for all the protein systems for which long folding simulation trajectories are available. To our knowledge, this is the first systematic demonstration of any kind of evolutionary conservation of amino acids relevant to folding kinetics.
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Affiliation(s)
- Song-Ho Chong
- Global Center for Natural Resources Sciences, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Sihyun Ham
- Department of Chemistry, Sookmyung Women's University, Seoul, South Korea
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10
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Lisowska M, Lickiss F, Gil-Mir M, Huart AS, Trybala Z, Way L, Hernychova L, Krejci A, Muller P, Krejcir R, Zhukow I, Jurczak P, Rodziewicz-Motowidło S, Ball K, Vojtesek B, Hupp T, Kalathiya U. Next-generation sequencing of a combinatorial peptide phage library screened against ubiquitin identifies peptide aptamers that can inhibit the in vitro ubiquitin transfer cascade. Front Microbiol 2022; 13:875556. [PMID: 36532480 PMCID: PMC9755681 DOI: 10.3389/fmicb.2022.875556] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 10/13/2022] [Indexed: 09/01/2023] Open
Abstract
Defining dynamic protein-protein interactions in the ubiquitin conjugation reaction is a challenging research area. Generating peptide aptamers that target components such as ubiquitin itself, E1, E2, or E3 could provide tools to dissect novel features of the enzymatic cascade. Next-generation deep sequencing platforms were used to identify peptide sequences isolated from phage-peptide libraries screened against Ubiquitin and its ortholog NEDD8. In over three rounds of selection under differing wash criteria, over 13,000 peptides were acquired targeting ubiquitin, while over 10,000 peptides were selected against NEDD8. The overlap in peptides against these two proteins was less than 5% suggesting a high degree in specificity of Ubiquitin or NEDD8 toward linear peptide motifs. Two of these ubiquitin-binding peptides were identified that inhibit both E3 ubiquitin ligases MDM2 and CHIP. NMR analysis highlighted distinct modes of binding of the two different peptide aptamers. These data highlight the utility of using next-generation sequencing of combinatorial phage-peptide libraries to isolate peptide aptamers toward a protein target that can be used as a chemical tool in a complex multi-enzyme reaction.
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Affiliation(s)
- Małgorzata Lisowska
- International Centre for Cancer Vaccine Science, University of Gdańsk, Gdańsk, Poland
| | - Fiona Lickiss
- International Centre for Cancer Vaccine Science, University of Gdańsk, Gdańsk, Poland
| | - Maria Gil-Mir
- University of Edinburgh, Institute of Genetics and Molecular Medicine, Edinburgh, United Kingdom
| | - Anne-Sophie Huart
- University of Edinburgh, Institute of Genetics and Molecular Medicine, Edinburgh, United Kingdom
| | - Zuzanna Trybala
- International Centre for Cancer Vaccine Science, University of Gdańsk, Gdańsk, Poland
| | - Luke Way
- University of Edinburgh, Institute of Genetics and Molecular Medicine, Edinburgh, United Kingdom
| | - Lenka Hernychova
- Research Centre for Applied Molecular Oncology, Masaryk Memorial Cancer Institute, Brno, Czechia
| | - Adam Krejci
- Research Centre for Applied Molecular Oncology, Masaryk Memorial Cancer Institute, Brno, Czechia
| | - Petr Muller
- Research Centre for Applied Molecular Oncology, Masaryk Memorial Cancer Institute, Brno, Czechia
| | - Radovan Krejcir
- Research Centre for Applied Molecular Oncology, Masaryk Memorial Cancer Institute, Brno, Czechia
| | - Igor Zhukow
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | | | | | - Kathryn Ball
- University of Edinburgh, Institute of Genetics and Molecular Medicine, Edinburgh, United Kingdom
| | - Borivoj Vojtesek
- Research Centre for Applied Molecular Oncology, Masaryk Memorial Cancer Institute, Brno, Czechia
| | - Ted Hupp
- University of Edinburgh, Institute of Genetics and Molecular Medicine, Edinburgh, United Kingdom
| | - Umesh Kalathiya
- International Centre for Cancer Vaccine Science, University of Gdańsk, Gdańsk, Poland
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11
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Kelsall IR. Non-lysine ubiquitylation: Doing things differently. Front Mol Biosci 2022; 9:1008175. [PMID: 36200073 PMCID: PMC9527308 DOI: 10.3389/fmolb.2022.1008175] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Accepted: 09/01/2022] [Indexed: 11/23/2022] Open
Abstract
The post-translational modification of proteins with ubiquitin plays a central role in nearly all aspects of eukaryotic biology. Historically, studies have focused on the conjugation of ubiquitin to lysine residues in substrates, but it is now clear that ubiquitylation can also occur on cysteine, serine, and threonine residues, as well as on the N-terminal amino group of proteins. Paradigm-shifting reports of non-proteinaceous substrates have further extended the reach of ubiquitylation beyond the proteome to include intracellular lipids and sugars. Additionally, results from bacteria have revealed novel ways to ubiquitylate (and deubiquitylate) substrates without the need for any of the enzymatic components of the canonical ubiquitylation cascade. Focusing mainly upon recent findings, this review aims to outline the current understanding of non-lysine ubiquitylation and speculate upon the molecular mechanisms and physiological importance of this non-canonical modification.
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12
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Thellung S, Corsaro A, Dellacasagrande I, Nizzari M, Zambito M, Florio T. Proteostasis unbalance in prion diseases: Mechanisms of neurodegeneration and therapeutic targets. Front Neurosci 2022; 16:966019. [PMID: 36148145 PMCID: PMC9485628 DOI: 10.3389/fnins.2022.966019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 08/05/2022] [Indexed: 01/18/2023] Open
Abstract
Transmissible spongiform encephalopathies (TSEs), or prion diseases, are progressive neurodegenerative disorders of the central nervous system that affect humans and animals as sporadic, inherited, and infectious forms. Similarly to Alzheimer's disease and other neurodegenerative disorders, any attempt to reduce TSEs' lethality or increase the life expectancy of affected individuals has been unsuccessful. Typically, the onset of symptoms anticipates the fatal outcome of less than 1 year, although it is believed to be the consequence of a decades-long process of neuronal death. The duration of the symptoms-free period represents by itself a major obstacle to carry out effective neuroprotective therapies. Prions, the infectious entities of TSEs, are composed of a protease-resistant protein named prion protein scrapie (PrPSc) from the prototypical TSE form that afflicts ovines. PrPSc misfolding from its physiological counterpart, cellular prion protein (PrPC), is the unifying pathogenic trait of all TSEs. PrPSc is resistant to intracellular turnover and undergoes amyloid-like fibrillation passing through the formation of soluble dimers and oligomers, which are likely the effective neurotoxic entities. The failure of PrPSc removal is a key pathogenic event that defines TSEs as proteopathies, likewise other neurodegenerative disorders, including Alzheimer's, Parkinson's, and Huntington's disease, characterized by alteration of proteostasis. Under physiological conditions, protein quality control, led by the ubiquitin-proteasome system, and macroautophagy clears cytoplasm from improperly folded, redundant, or aggregation-prone proteins. There is evidence that both of these crucial homeostatic pathways are impaired during the development of TSEs, although it is still unclear whether proteostasis alteration facilitates prion protein misfolding or, rather, PrPSc protease resistance hampers cytoplasmic protein quality control. This review is aimed to critically analyze the most recent advancements in the cause-effect correlation between PrPC misfolding and proteostasis alterations and to discuss the possibility that pharmacological restoring of ubiquitin-proteasomal competence and stimulation of autophagy could reduce the intracellular burden of PrPSc and ameliorate the severity of prion-associated neurodegeneration.
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Affiliation(s)
- Stefano Thellung
- Section of Pharmacology, Department of Internal Medicine (DiMI), University of Genova, Genova, Italy
| | - Alessandro Corsaro
- Section of Pharmacology, Department of Internal Medicine (DiMI), University of Genova, Genova, Italy
| | - Irene Dellacasagrande
- Section of Pharmacology, Department of Internal Medicine (DiMI), University of Genova, Genova, Italy
| | - Mario Nizzari
- Section of Pharmacology, Department of Internal Medicine (DiMI), University of Genova, Genova, Italy
| | - Martina Zambito
- Section of Pharmacology, Department of Internal Medicine (DiMI), University of Genova, Genova, Italy
| | - Tullio Florio
- Section of Pharmacology, Department of Internal Medicine (DiMI), University of Genova, Genova, Italy
- IRCCS Ospedale Policlinico San Martino, Genova, Italy
- *Correspondence: Tullio Florio
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13
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Orosa-Puente B, Spoel SH. Harnessing the ubiquitin code to respond to environmental cues. Essays Biochem 2022; 66:111-121. [PMID: 35880291 PMCID: PMC9400065 DOI: 10.1042/ebc20210094] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 06/13/2022] [Accepted: 06/27/2022] [Indexed: 12/15/2022]
Abstract
Ubiquitination is an essential post-translational signal that allows cells to adapt and respond to environmental stimuli. Substrate modifications range from a single ubiquitin molecule to complex polyubiquitin chains, where diverse chain topologies constitute a code that is utilized to modify the functions of proteins in numerous cellular signalling pathways. Diverse ubiquitin chain topologies are generated by linking the C-terminus of ubiquitin to one of seven lysine residues or the N-terminal methionine 1 residue of the preceding ubiquitin. Cooperative action between a large array of E2 conjugating and E3 ligase enzymes supports the formation of not only homotypic ubiquitin chains but also heterotypic mixed or branched chains. This complex array of chain topologies is recognized by proteins containing linkage-specific ubiquitin-binding domains and regulates numerous cellular pathways. Although many functions of the ubiquitin code in plants remain unknown, recent work suggests that specific chain topologies are associated with particular molecular processes. Deciphering the ubiquitin code and how plants utilize it to cope with the changing environment is essential to understand the regulatory mechanisms that underpin myriad stress responses and establishment of environmental tolerance.
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Affiliation(s)
- Beatriz Orosa-Puente
- Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, Edinburgh EH16 5JF, U.K
| | - Steven H Spoel
- Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, Edinburgh EH16 5JF, U.K
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14
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Zhu L, Zhang Q, Cordeiro CD, Banjade S, Sardana R, Mao Y, Emr SD. Adaptor linked K63 di-ubiquitin activates Nedd4/Rsp5 E3 ligase. eLife 2022; 11:77424. [PMID: 35770973 PMCID: PMC9282857 DOI: 10.7554/elife.77424] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 06/08/2022] [Indexed: 11/13/2022] Open
Abstract
Nedd4/Rsp5 family E3 ligases mediate numerous cellular processes, many of which require the E3 ligase to interact with PY motif containing adaptor proteins. Several arrestin-related trafficking adaptors (ARTs) of Rsp5 were self-ubiquitinated for activation, but the regulation mechanism remains elusive. Remarkably, we demonstrate that Art1, Art4, and Art5 undergo K63-linked di-ubiquitination by Rsp5. This modification enhances the plasma membrane recruitment of Rsp5 by Art1 or Art5 upon substrate induction, required for cargo protein ubiquitination. In agreement with these observations, we find that di-ubiquitin strengthens the interaction between the pombe orthologs of Rsp5 and Art1, Pub1, and Any1. Furthermore, we discover that the homologous to E6AP C-terminus (HECT) domain exosite protects the K63-linked di-ubiquitin on the adaptors from cleavage by the deubiquitination enzyme Ubp2. Together, our study uncovers a novel ubiquitination modification implemented by Rsp5 adaptor proteins, underscoring the regulatory mechanism of how adaptor proteins control the recruitment, and activity of Rsp5 for the turnover of membrane proteins.
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Affiliation(s)
- Lu Zhu
- Weill Institute of Cell and Molecular Biology, Cornell UniversityIthacaUnited States,Department of Molecular Biology and Genetics, Cornell UniversityIthacaUnited States
| | - Qing Zhang
- Weill Institute of Cell and Molecular Biology, Cornell UniversityIthacaUnited States,Department of Molecular Biology and Genetics, Cornell UniversityIthacaUnited States
| | - Ciro D Cordeiro
- Weill Institute of Cell and Molecular Biology, Cornell UniversityIthacaUnited States,Department of Molecular Biology and Genetics, Cornell UniversityIthacaUnited States
| | - Sudeep Banjade
- Weill Institute of Cell and Molecular Biology, Cornell UniversityIthacaUnited States,Department of Molecular Biology and Genetics, Cornell UniversityIthacaUnited States
| | - Richa Sardana
- Weill Institute of Cell and Molecular Biology, Cornell UniversityIthacaUnited States,Department of Molecular Biology and Genetics, Cornell UniversityIthacaUnited States
| | - Yuxin Mao
- Weill Institute of Cell and Molecular Biology, Cornell UniversityIthacaUnited States,Department of Molecular Biology and Genetics, Cornell UniversityIthacaUnited States
| | - Scott D Emr
- Weill Institute of Cell and Molecular Biology, Cornell UniversityIthacaUnited States,Department of Molecular Biology and Genetics, Cornell UniversityIthacaUnited States
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15
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van den Heuvel J, Ashiono C, Gillet LC, Dörner K, Wyler E, Zemp I, Kutay U. Processing of the ribosomal ubiquitin-like fusion protein FUBI-eS30/FAU is required for 40S maturation and depends on USP36. eLife 2021; 10:70560. [PMID: 34318747 PMCID: PMC8354635 DOI: 10.7554/elife.70560] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 07/27/2021] [Indexed: 12/13/2022] Open
Abstract
In humans and other holozoan organisms, the ribosomal protein eS30 is synthesized as a fusion protein with the ubiquitin-like protein FUBI. However, FUBI is not part of the mature 40S ribosomal subunit and cleaved off by an as-of-yet unidentified protease. How FUBI-eS30 processing is coordinated with 40S subunit maturation is unknown. To study the mechanism and importance of FUBI-eS30 processing, we expressed non-cleavable mutants in human cells, which affected late steps of cytoplasmic 40S maturation, including the maturation of 18S rRNA and recycling of late-acting ribosome biogenesis factors. Differential affinity purification of wild-type and non-cleavable FUBI-eS30 mutants identified the deubiquitinase USP36 as a candidate FUBI-eS30 processing enzyme. Depletion of USP36 by RNAi or CRISPRi indeed impaired FUBI-eS30 processing and moreover, purified USP36 cut FUBI-eS30 in vitro. Together, these data demonstrate the functional importance of FUBI-eS30 cleavage and identify USP36 as a novel protease involved in this process.
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Affiliation(s)
- Jasmin van den Heuvel
- Institute of Biochemistry, Department of Biology, ETH Zurich, Zurich, Switzerland.,Molecular Life Sciences Ph.D. Program, Zurich, Switzerland
| | - Caroline Ashiono
- Institute of Biochemistry, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Ludovic C Gillet
- Institute of Biochemistry, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Kerstin Dörner
- Institute of Biochemistry, Department of Biology, ETH Zurich, Zurich, Switzerland.,Molecular Life Sciences Ph.D. Program, Zurich, Switzerland
| | - Emanuel Wyler
- Institute of Biochemistry, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Ivo Zemp
- Institute of Biochemistry, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Ulrike Kutay
- Institute of Biochemistry, Department of Biology, ETH Zurich, Zurich, Switzerland
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16
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Hepowit NL, Kolbe CC, Zelle SR, Latz E, MacGurn JA. Regulation of ubiquitin and ubiquitin-like modifiers by phosphorylation. FEBS J 2021; 289:4797-4810. [PMID: 34214249 PMCID: PMC9271371 DOI: 10.1111/febs.16101] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 05/28/2021] [Accepted: 07/01/2021] [Indexed: 12/31/2022]
Abstract
The regulatory influence of ubiquitin is vast, encompassing all cellular processes, by virtue of its central roles in protein degradation, membrane trafficking, and cell signaling. But how does ubiquitin, a 76 amino acid peptide, carry out such diverse, complex functions in eukaryotic cells? Part of the answer is rooted in the high degree of complexity associated with ubiquitin polymers, which can be 'read' and processed differently depending on topology and cellular context. However, recent evidence indicates that post-translational modifications on ubiquitin itself enhance the complexity of the ubiquitin code. Here, we review recent discoveries related to the regulation of the ubiquitin code by phosphorylation. We summarize what is currently known about phosphorylation of ubiquitin at Ser65, Ser57, and Thr12, and we discuss the potential for phosphoregulation of ubiquitin at other sites. We also discuss accumulating evidence that ubiquitin-like modifiers, such as SUMO, are likewise regulated by phosphorylation. A complete understanding of these regulatory codes and their complex lexicon will require dissection of mechanisms that govern phosphorylation of ubiquitin and ubiquitin-like proteins, particularly in the context of cellular stress and disease.
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Affiliation(s)
- Nathaniel L Hepowit
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN, USA
| | - Carl-Christian Kolbe
- Institute of Innate Immunity, University Hospital Bonn, University of Bonn, Germany
| | - Sarah R Zelle
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN, USA
| | - Eicke Latz
- Institute of Innate Immunity, University Hospital Bonn, University of Bonn, Germany.,German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.,Department of Infectious Diseases & Immunology, UMass Medical School, Worcester, MA, USA.,Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, Trondheim, Norway
| | - Jason A MacGurn
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN, USA
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17
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Mechanistic basis for ubiquitin modulation of a protein energy landscape. Proc Natl Acad Sci U S A 2021; 118:2025126118. [PMID: 33723075 DOI: 10.1073/pnas.2025126118] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Ubiquitin is a common posttranslational modification canonically associated with targeting proteins to the 26S proteasome for degradation and also plays a role in numerous other nondegradative cellular processes. Ubiquitination at certain sites destabilizes the substrate protein, with consequences for proteasomal processing, while ubiquitination at other sites has little energetic effect. How this site specificity-and, by extension, the myriad effects of ubiquitination on substrate proteins-arises remains unknown. Here, we systematically characterize the atomic-level effects of ubiquitination at various sites on a model protein, barstar, using a combination of NMR, hydrogen-deuterium exchange mass spectrometry, and molecular dynamics simulation. We find that, regardless of the site of modification, ubiquitination does not induce large structural rearrangements in the substrate. Destabilizing modifications, however, increase fluctuations from the native state resulting in exposure of the substrate's C terminus. Both of the sites occur in regions of barstar with relatively high conformational flexibility. Nevertheless, destabilization appears to occur through different thermodynamic mechanisms, involving a reduction in entropy in one case and a loss in enthalpy in another. By contrast, ubiquitination at a nondestabilizing site protects the substrate C terminus through intermittent formation of a structural motif with the last three residues of ubiquitin. Thus, the biophysical effects of ubiquitination at a given site depend greatly on local context. Taken together, our results reveal how a single posttranslational modification can generate a broad array of distinct effects, providing a framework to guide the design of proteins and therapeutics with desired degradation and quality control properties.
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18
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Sharma M, Yadav P, Doshi A, Brahmbhatt HD, Prabha CR. Probing the effects of double mutations on the versatile protein ubiquitin in Saccharomyces cerevisiae. Int J Biol Macromol 2021; 179:299-308. [PMID: 33662424 DOI: 10.1016/j.ijbiomac.2021.02.208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 02/21/2021] [Accepted: 02/27/2021] [Indexed: 11/17/2022]
Abstract
Ubiquitin is an indispensable protein of eukaryotic origin with an extraordinarily high degree of sequence conservation. It is used to tag proteins post-translationally and the process of ubiquitination regulates the activity of the modified proteins or drives them for degradation. Double mutations produce varied effects in proteins, depending on the structural relationship of the mutated residues, their role in the overall structure and functions of a protein. Six double mutants derived from the ubiquitin mutant UbEP42, namely S20F-A46S, S20F-L50P, S20F-I61T, A46S-L50P, A46S-I61T, and L50P-I61T, have been studied here to understand how they influence the ubiquitination related functions, by analysing their growth and viability, Cdc28 levels, K-48 linked polyubiquitination, UFD pathway, lysosomal degradation, endosomal sorting, survival under heat, and antibiotic stresses. The double mutation L50P-I61T is the most detrimental, followed by S20F-I61T and A46S-I61T. The double mutations studied here, in general, make cells more sensitive than the wild type to one or the other stress. However, the excessive negative effects of L50P and I61T are compensated under certain conditions by S20F and A46S mutations. The competitive inhibition produced by these substitutions could be used to manage certain ubiquitination associated diseases.
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Affiliation(s)
- Mrinal Sharma
- Department of Biochemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara 390002, India
| | - Prranshu Yadav
- Department of Biochemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara 390002, India
| | - Ankita Doshi
- Department of Biochemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara 390002, India
| | - Hemang D Brahmbhatt
- Department of Biochemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara 390002, India
| | - C Ratna Prabha
- Department of Biochemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara 390002, India.
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19
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Kang JA, Jeon YJ. How Is the Fidelity of Proteins Ensured in Terms of Both Quality and Quantity at the Endoplasmic Reticulum? Mechanistic Insights into E3 Ubiquitin Ligases. Int J Mol Sci 2021; 22:ijms22042078. [PMID: 33669844 PMCID: PMC7923238 DOI: 10.3390/ijms22042078] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 02/16/2021] [Accepted: 02/16/2021] [Indexed: 02/06/2023] Open
Abstract
The endoplasmic reticulum (ER) is an interconnected organelle that plays fundamental roles in the biosynthesis, folding, stabilization, maturation, and trafficking of secretory and transmembrane proteins. It is the largest organelle and critically modulates nearly all aspects of life. Therefore, in the endoplasmic reticulum, an enormous investment of resources, including chaperones and protein folding facilitators, is dedicated to adequate protein maturation and delivery to final destinations. Unfortunately, the folding and assembly of proteins can be quite error-prone, which leads to the generation of misfolded proteins. Notably, protein homeostasis, referred to as proteostasis, is constantly exposed to danger by flows of misfolded proteins and subsequent protein aggregates. To maintain proteostasis, the ER triages and eliminates terminally misfolded proteins by delivering substrates to the ubiquitin–proteasome system (UPS) or to the lysosome, which is termed ER-associated degradation (ERAD) or ER-phagy, respectively. ERAD not only eliminates misfolded or unassembled proteins via protein quality control but also fine-tunes correctly folded proteins via protein quantity control. Intriguingly, the diversity and distinctive nature of E3 ubiquitin ligases determine efficiency, complexity, and specificity of ubiquitination during ERAD. ER-phagy utilizes the core autophagy machinery and eliminates ERAD-resistant misfolded proteins. Here, we conceptually outline not only ubiquitination machinery but also catalytic mechanisms of E3 ubiquitin ligases. Further, we discuss the mechanistic insights into E3 ubiquitin ligases involved in the two guardian pathways in the ER, ERAD and ER-phagy. Finally, we provide the molecular mechanisms by which ERAD and ER-phagy conduct not only protein quality control but also protein quantity control to ensure proteostasis and subsequent organismal homeostasis.
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Affiliation(s)
- Ji An Kang
- Department of Biochemistry, College of Medicine, Chungnam National University, Daejeon 35015, Korea;
- Department of Medical Science, College of Medicine, Chungnam National University, Daejeon 35015, Korea
| | - Young Joo Jeon
- Department of Biochemistry, College of Medicine, Chungnam National University, Daejeon 35015, Korea;
- Department of Medical Science, College of Medicine, Chungnam National University, Daejeon 35015, Korea
- Correspondence:
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20
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Abstract
The 26S proteasome is the most complex ATP-dependent protease machinery, of ~2.5 MDa mass, ubiquitously found in all eukaryotes. It selectively degrades ubiquitin-conjugated proteins and plays fundamentally indispensable roles in regulating almost all major aspects of cellular activities. To serve as the sole terminal "processor" for myriad ubiquitylation pathways, the proteasome evolved exceptional adaptability in dynamically organizing a large network of proteins, including ubiquitin receptors, shuttle factors, deubiquitinases, AAA-ATPase unfoldases, and ubiquitin ligases, to enable substrate selectivity and processing efficiency and to achieve regulation precision of a vast diversity of substrates. The inner working of the 26S proteasome is among the most sophisticated, enigmatic mechanisms of enzyme machinery in eukaryotic cells. Recent breakthroughs in three-dimensional atomic-level visualization of the 26S proteasome dynamics during polyubiquitylated substrate degradation elucidated an extensively detailed picture of its functional mechanisms, owing to progressive methodological advances associated with cryogenic electron microscopy (cryo-EM). Multiple sites of ubiquitin binding in the proteasome revealed a canonical mode of ubiquitin-dependent substrate engagement. The proteasome conformation in the act of substrate deubiquitylation provided insights into how the deubiquitylating activity of RPN11 is enhanced in the holoenzyme and is coupled to substrate translocation. Intriguingly, three principal modes of coordinated ATP hydrolysis in the heterohexameric AAA-ATPase motor were discovered to regulate intermediate functional steps of the proteasome, including ubiquitin-substrate engagement, deubiquitylation, initiation of substrate translocation and processive substrate degradation. The atomic dissection of the innermost working of the 26S proteasome opens up a new era in our understanding of the ubiquitin-proteasome system and has far-reaching implications in health and disease.
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Affiliation(s)
- Youdong Mao
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, 02215, Massachusetts, USA. .,School of Physics, Center for Quantitative Biology, Peking University, Beijing, 100871, China.
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21
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Blount JR, Johnson SL, Todi SV. Unanchored Ubiquitin Chains, Revisited. Front Cell Dev Biol 2020; 8:582361. [PMID: 33195227 PMCID: PMC7659471 DOI: 10.3389/fcell.2020.582361] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 09/15/2020] [Indexed: 12/20/2022] Open
Abstract
The small modifier protein, ubiquitin, holds a special place in eukaryotic biology because of its myriad post-translational effects that control normal cellular processes and are implicated in various diseases. By being covalently conjugated onto other proteins, ubiquitin changes their interaction landscape - fostering new interactions as well as inhibiting others - and ultimately deciding the fate of its substrates and controlling pathways that span most cell physiology. Ubiquitin can be attached onto other proteins as a monomer or as a poly-ubiquitin chain of diverse structural topologies. Among the types of poly-ubiquitin species generated are ones detached from another substrate - comprising solely ubiquitin as their constituent - referred to as unanchored, or free chains. Considered to be toxic byproducts, these species have recently emerged to have specific physiological functions in immune pathways and during cell stress. Free chains also do not appear to be detrimental to multi-cellular organisms; they can be active members of the ubiquitination process, rather than corollary species awaiting disassembly into mono-ubiquitin. Here, we summarize past and recent studies on unanchored ubiquitin chains, paying special attention to their emerging roles as second messengers in several signaling pathways. These investigations paint complex and flexible outcomes for free ubiquitin chains, and present a revised model of unanchored poly-ubiquitin biology that is in need of additional investigation.
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Affiliation(s)
- Jessica R Blount
- Department of Pharmacology, Wayne State University School of Medicine, Detroit, MI, United States
| | - Sean L Johnson
- Department of Pharmacology, Wayne State University School of Medicine, Detroit, MI, United States
| | - Sokol V Todi
- Department of Pharmacology, Wayne State University School of Medicine, Detroit, MI, United States.,Department of Neurology, Wayne State University School of Medicine, Detroit, MI, United States
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22
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Hepowit NL, Pereira KN, Tumolo JM, Chazin WJ, MacGurn JA. Identification of ubiquitin Ser57 kinases regulating the oxidative stress response in yeast. eLife 2020; 9:58155. [PMID: 33074099 PMCID: PMC7647399 DOI: 10.7554/elife.58155] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 10/18/2020] [Indexed: 01/26/2023] Open
Abstract
Ubiquitination regulates many different cellular processes, including protein quality control, membrane trafficking, and stress responses. The diversity of ubiquitin functions in the cell is partly due to its ability to form chains with distinct linkages that can alter the fate of substrate proteins in unique ways. The complexity of the ubiquitin code is further enhanced by post-translational modifications on ubiquitin itself, the biological functions of which are not well understood. Here, we present genetic and biochemical evidence that serine 57 (Ser57) phosphorylation of ubiquitin functions in stress responses in Saccharomyces cerevisiae, including the oxidative stress response. We also identify and characterize the first known Ser57 ubiquitin kinases in yeast and human cells, and we report that two Ser57 ubiquitin kinases regulate the oxidative stress response in yeast. These studies implicate ubiquitin phosphorylation at the Ser57 position as an important modifier of ubiquitin function, particularly in response to proteotoxic stress.
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Affiliation(s)
- Nathaniel L Hepowit
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, United States
| | - Kevin N Pereira
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, United States
| | - Jessica M Tumolo
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, United States
| | - Walter J Chazin
- Department of Biochemistry, Vanderbilt University, Nashville, United States
| | - Jason A MacGurn
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, United States
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23
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Vallejo-Castillo L, Favari L, Vázquez-Leyva S, Mellado-Sánchez G, Macías-Palacios Z, López-Juárez LE, Valencia-Flores L, Medina-Rivero E, Chacón-Salinas R, Pavón L, Pérez-Tapia SM. Sequencing Analysis and Identification of the Primary Peptide Component of the Dialyzable Leukocyte Extract "Transferon Oral": The Starting Point to Understand Its Mechanism of Action. Front Pharmacol 2020; 11:569039. [PMID: 33117165 PMCID: PMC7577238 DOI: 10.3389/fphar.2020.569039] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 09/16/2020] [Indexed: 02/02/2023] Open
Abstract
"Transferon Oral" is a peptide-derived product with immunomodulatory properties obtained from the lysis and dialysis of human buffy coat. Its active pharmaceutical ingredient, generically known as Dialyzable Leucocyte Extract, is a mixture of peptide populations with reproducible proportions among batches. "Transferon Oral" modulates IFN-γ, TNF-α, and IL-6 and increases the survival rate in a herpes infection murine model when oropharyngeally (ORO) administered, which correlate with clinical observations where "Transferon Oral" is used as a therapeutic auxiliary in inflammatory diseases. Notwithstanding, how a peptide-derived product elicits systemic modulation of cytokines when ORO administered remains unclear. To shed light on the pharmacology of "Transferon Oral" its peptide components must be known. Ten "Transferon Oral" batches were sequenced by mass spectrometry and the intact peptides were identified. The most abundant peptides were the monomeric human Ubiquitin (Ub), a globular low-molecular mass protein, and an Ub variant which lacks the two-terminal Gly (Ub-GG). Recombinant Ub prevented murine death when ORO administered in a herpes infection murine model. Besides, the percentage of survival increased in groups treated with Transferon Oral+Ub and decreased in groups treated with Ub-depleted "Transferon Oral" respect to the group treated with "Transferon Oral" only. Our findings indicate that the biological properties of "Transferon Oral" are partially associated to the Ub content. They suggest that Ub may activate its extracellular receptor (CXCR-4) in the stomach eliciting systemic immunomodulatory effects via vagus nerve. This is the first report that identifies an active component of "Transferon Oral" with the potential for the development of oral peptide immunomodulators.
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Affiliation(s)
- Luis Vallejo-Castillo
- Unidad de Desarrollo e Investigación en Bioprocesos (UDIBI), Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
- Departamento de Farmacología, Centro de Investigación y de Estudios Avanzados del IPN, Ciudad de México, Mexico
- Laboratorio Nacional para Servicios Especializados de Investigación, Desarrollo e Innovación (I + D + i) para Farmoquímicos y Biotecnológicos (LANSEIDI-FarBiotec-CONACyT), Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
| | - Liliana Favari
- Departamento de Farmacología, Centro de Investigación y de Estudios Avanzados del IPN, Ciudad de México, Mexico
| | - Said Vázquez-Leyva
- Unidad de Desarrollo e Investigación en Bioprocesos (UDIBI), Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
- Laboratorio Nacional para Servicios Especializados de Investigación, Desarrollo e Innovación (I + D + i) para Farmoquímicos y Biotecnológicos (LANSEIDI-FarBiotec-CONACyT), Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
| | - Gabriela Mellado-Sánchez
- Unidad de Desarrollo e Investigación en Bioprocesos (UDIBI), Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
- Laboratorio Nacional para Servicios Especializados de Investigación, Desarrollo e Innovación (I + D + i) para Farmoquímicos y Biotecnológicos (LANSEIDI-FarBiotec-CONACyT), Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
| | - Zaira Macías-Palacios
- Unidad de Desarrollo e Investigación en Bioprocesos (UDIBI), Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
- Laboratorio Nacional para Servicios Especializados de Investigación, Desarrollo e Innovación (I + D + i) para Farmoquímicos y Biotecnológicos (LANSEIDI-FarBiotec-CONACyT), Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
| | - Leonardo E. López-Juárez
- Unidad de Desarrollo e Investigación en Bioprocesos (UDIBI), Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
- Laboratorio Nacional para Servicios Especializados de Investigación, Desarrollo e Innovación (I + D + i) para Farmoquímicos y Biotecnológicos (LANSEIDI-FarBiotec-CONACyT), Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
| | - Luis Valencia-Flores
- Unidad de Desarrollo e Investigación en Bioprocesos (UDIBI), Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
- Laboratorio Nacional para Servicios Especializados de Investigación, Desarrollo e Innovación (I + D + i) para Farmoquímicos y Biotecnológicos (LANSEIDI-FarBiotec-CONACyT), Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
| | - Emilio Medina-Rivero
- Unidad de Desarrollo e Investigación en Bioprocesos (UDIBI), Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
| | - Rommel Chacón-Salinas
- Departamento de Inmunología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
| | - Lenin Pavón
- Laboratorio de Psicoinmunología, Dirección de Investigaciones en Neurociencias, Instituto Nacional de Psiquiatría Ramón de la Fuente., Mexico City, Mexico
| | - Sonia Mayra Pérez-Tapia
- Unidad de Desarrollo e Investigación en Bioprocesos (UDIBI), Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
- Laboratorio Nacional para Servicios Especializados de Investigación, Desarrollo e Innovación (I + D + i) para Farmoquímicos y Biotecnológicos (LANSEIDI-FarBiotec-CONACyT), Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
- Departamento de Inmunología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
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Walser F, Mulder MPC, Bragantini B, Burger S, Gubser T, Gatti M, Botuyan MV, Villa A, Altmeyer M, Neri D, Ovaa H, Mer G, Penengo L. Ubiquitin Phosphorylation at Thr12 Modulates the DNA Damage Response. Mol Cell 2020; 80:423-436.e9. [PMID: 33022275 DOI: 10.1016/j.molcel.2020.09.017] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 04/14/2020] [Accepted: 09/12/2020] [Indexed: 11/26/2022]
Abstract
The ubiquitin system regulates the DNA damage response (DDR) by modifying histone H2A at Lys15 (H2AK15ub) and triggering downstream signaling events. Here, we find that phosphorylation of ubiquitin at Thr12 (pUbT12) controls the DDR by inhibiting the function of 53BP1, a key factor for DNA double-strand break repair by non-homologous end joining (NHEJ). Detectable as a chromatin modification on H2AK15ub, pUbT12 accumulates in nuclear foci and is increased upon DNA damage. Mutating Thr12 prevents the removal of ubiquitin from H2AK15ub by USP51 deubiquitinating enzyme, leading to a pronounced accumulation of ubiquitinated chromatin. Chromatin modified by pUbT12 is inaccessible to 53BP1 but permissive to the homologous recombination (HR) proteins RNF169, RAD51, and the BRCA1/BARD1 complex. Phosphorylation of ubiquitin at Thr12 in the chromatin context is a new histone mark, H2AK15pUbT12, that regulates the DDR by hampering the activity of 53BP1 at damaged chromosomes.
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Affiliation(s)
- Franziska Walser
- Institute of Molecular Cancer Research, University of Zurich, 8057 Zurich, Switzerland
| | - Monique P C Mulder
- Department of Cell and Chemical Biology, Leiden University Medical Center, 2333 ZC Leiden, the Netherlands; Oncode Institute and Department of Cell and Chemical Biology, Chemical Immunology, Leiden University Medical Center, 2300 RC Leiden, the Netherlands
| | - Benoît Bragantini
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN 55905, USA
| | - Sibylle Burger
- Institute of Molecular Cancer Research, University of Zurich, 8057 Zurich, Switzerland
| | - Tatiana Gubser
- Institute of Molecular Cancer Research, University of Zurich, 8057 Zurich, Switzerland
| | - Marco Gatti
- Department of Molecular Mechanisms of Disease, University of Zurich, 8057 Zurich, Switzerland
| | | | - Alessandra Villa
- Department of Chemistry and Applied Biosciences, Swiss Federal Institute of Technology (ETH Zurich), 8093 Zurich, Switzerland
| | - Matthias Altmeyer
- Department of Molecular Mechanisms of Disease, University of Zurich, 8057 Zurich, Switzerland
| | - Dario Neri
- Department of Chemistry and Applied Biosciences, Swiss Federal Institute of Technology (ETH Zurich), 8093 Zurich, Switzerland
| | - Huib Ovaa
- Department of Cell and Chemical Biology, Leiden University Medical Center, 2333 ZC Leiden, the Netherlands; Oncode Institute and Department of Cell and Chemical Biology, Chemical Immunology, Leiden University Medical Center, 2300 RC Leiden, the Netherlands
| | - Georges Mer
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN 55905, USA
| | - Lorenza Penengo
- Institute of Molecular Cancer Research, University of Zurich, 8057 Zurich, Switzerland.
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25
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Blount JR, Libohova K, Silva GM, Todi SV. Isoleucine 44 Hydrophobic Patch Controls Toxicity of Unanchored, Linear Ubiquitin Chains through NF-κB Signaling. Cells 2020; 9:cells9061519. [PMID: 32580388 PMCID: PMC7348737 DOI: 10.3390/cells9061519] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 06/15/2020] [Accepted: 06/16/2020] [Indexed: 12/11/2022] Open
Abstract
Ubiquitination is a post-translational modification that regulates cellular processes by altering the interactions of proteins to which ubiquitin, a small protein adduct, is conjugated. Ubiquitination yields various products, including mono- and poly-ubiquitinated substrates, as well as unanchored poly-ubiquitin chains whose accumulation is considered toxic. We previously showed that transgenic, unanchored poly-ubiquitin is not problematic in Drosophila melanogaster. In the fruit fly, free chains exist in various lengths and topologies and are degraded by the proteasome; they are also conjugated onto other proteins as one unit, eliminating them from the free ubiquitin chain pool. Here, to further explore the notion of unanchored chain toxicity, we examined when free poly-ubiquitin might become problematic. We found that unanchored chains can be highly toxic if they resemble linear poly-ubiquitin that cannot be modified into other topologies. These species upregulate NF-κB signaling, and modulation of the levels of NF-κB components reduces toxicity. In additional studies, we show that toxicity from untethered, linear chains is regulated by isoleucine 44, which anchors a key interaction site for ubiquitin. We conclude that free ubiquitin chains can be toxic, but only in uncommon circumstances, such as when the ability of cells to modify and regulate them is markedly restricted.
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Affiliation(s)
- Jessica R. Blount
- Department of Pharmacology, Wayne State University School of Medicine, 540 East Canfield St., Scott Hall Rm. 3108, Detroit, MI 48201, USA; (J.R.B.); (K.L.)
| | - Kozeta Libohova
- Department of Pharmacology, Wayne State University School of Medicine, 540 East Canfield St., Scott Hall Rm. 3108, Detroit, MI 48201, USA; (J.R.B.); (K.L.)
| | | | - Sokol V. Todi
- Department of Pharmacology, Wayne State University School of Medicine, 540 East Canfield St., Scott Hall Rm. 3108, Detroit, MI 48201, USA; (J.R.B.); (K.L.)
- Department of Neurology, Wayne State University School of Medicine, 540 East Canfield St., Scott Hall Rm. 3108, Detroit, MI 48201, USA
- Correspondence:
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26
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Horx P, Geyer A. Defining the mobility range of a hinge-type connection using molecular dynamics and metadynamics. PLoS One 2020; 15:e0230962. [PMID: 32282813 PMCID: PMC7153902 DOI: 10.1371/journal.pone.0230962] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 03/12/2020] [Indexed: 01/29/2023] Open
Abstract
A designed disulfide-rich β-hairpin peptide that dimerizes spontaneously served as a hinge-type connection between proteins. Here, we analyze the range of dynamics of this hinge dimer with the aim of proposing new applications for the DNA-encodable peptide and establishing guidelines for the computational analysis of other disulfide hinges. A recent structural analysis based on nuclear magnetic resonance spectroscopy and ion mobility spectrometry revealed an averaged conformation in the hinge region which motivated us to investigate the dynamic behavior using a combination of molecular dynamics simulation, metadynamics and free energy surface analysis to characterize the conformational space available to the hinge. Principal component analysis uncovered two slow modes of the peptide, namely, the opening and closing motion and twisting of the two β-hairpins assembling the hinge. Applying a collective variable (CV) that mimics the first dominating mode, led to a major expansion of the conformational space. The description of the dynamics could be achieved by analysis of the opening angle and the twisting of the β-hairpins and, thus, offers a methodology that can also be transferred to other derivatives. It has been demonstrated that the hinge peptide’s lowest energy conformation consists of a large opening angle and strong twist but is separated by small energy barriers and can, thus, adopt a closed and untwisted structure. With the aim of proposing further applications for the hinge peptide, we simulated its behavior in the sterically congested environment of a four-helix bundle. Preliminary investigations show that one helix is pushed out and a three-helix bundle forms. The insights gained into the dynamics of the tetra-disulfide peptide and analytical guidelines developed in this study may contribute to the understanding of the structure and function of more complex hinge-type proteins, such as the IgG antibody family.
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Affiliation(s)
- Philip Horx
- Department of Chemistry, Philipps-Universität Marburg, Marburg, Germany
| | - Armin Geyer
- Department of Chemistry, Philipps-Universität Marburg, Marburg, Germany
- * E-mail:
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27
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Kliza K, Husnjak K. Resolving the Complexity of Ubiquitin Networks. Front Mol Biosci 2020; 7:21. [PMID: 32175328 PMCID: PMC7056813 DOI: 10.3389/fmolb.2020.00021] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 02/04/2020] [Indexed: 12/22/2022] Open
Abstract
Ubiquitination regulates nearly all cellular processes by coordinated activity of ubiquitin writers (E1, E2, and E3 enzymes), erasers (deubiquitinating enzymes) and readers (proteins that recognize ubiquitinated proteins by their ubiquitin-binding domains). By differentially modifying cellular proteome and by recognizing these ubiquitin modifications, ubiquitination machinery tightly regulates execution of specific cellular events in space and time. Dynamic and complex ubiquitin architecture, ranging from monoubiquitination, multiple monoubiquitination, eight different modes of homotypic and numerous types of heterogeneous polyubiquitin linkages, enables highly dynamic and complex regulation of cellular processes. We discuss available tools and approaches to study ubiquitin networks, including methods for the identification and quantification of ubiquitin-modified substrates, as well as approaches to quantify the length, abundance, linkage type and architecture of different ubiquitin chains. Furthermore, we also summarize the available approaches for the discovery of novel ubiquitin readers and ubiquitin-binding domains, as well as approaches to monitor and visualize activity of ubiquitin conjugation and deconjugation machineries. We also discuss benefits, drawbacks and limitations of available techniques, as well as what is still needed for detailed spatiotemporal dissection of cellular ubiquitination networks.
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Affiliation(s)
- Katarzyna Kliza
- Institute of Biochemistry II, Medical Faculty, Goethe University, Frankfurt, Germany
| | - Koraljka Husnjak
- Institute of Biochemistry II, Medical Faculty, Goethe University, Frankfurt, Germany
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28
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Shahul Hameed D, van Tilburg GBA, Merkx R, Flierman D, Wienk H, El Oualid F, Hofmann K, Boelens R, Ovaa H. Diubiquitin-Based NMR Analysis: Interactions Between Lys6-Linked diUb and UBA Domain of UBXN1. Front Chem 2020; 7:921. [PMID: 32039147 PMCID: PMC6987245 DOI: 10.3389/fchem.2019.00921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 12/18/2019] [Indexed: 12/03/2022] Open
Abstract
Ubiquitination is a process in which a protein is modified by the covalent attachment of the C-terminal carboxylic acid of ubiquitin (Ub) to the ε-amine of lysine or N-terminal methionine residue of a substrate protein or another Ub molecule. Each of the seven internal lysine residues and the N-terminal methionine residue of Ub can be linked to the C-terminus of another Ub moiety to form 8 distinct Ub linkages and the resulting differences in linkage types elicit different Ub signaling pathways. Cellular responses are triggered when proteins containing ubiquitin-binding domains (UBDs) recognize and bind to specific polyUb linkage types. To get more insight into the differences between polyUb chains, all of the seven lysine-linked di-ubiquitin molecules (diUbs) were prepared and used as a model to study their structural conformations in solution using NMR spectroscopy. We report the synthesis of diUb molecules, fully 15N-labeled on the distal (N-terminal) Ub moiety and revealed their structural orientation with respect to the proximal Ub. As expected, the diUb molecules exist in different conformations in solution, with multiple conformations known to exist for K6-, K48-, and K63-linked diUb molecules. These multiple conformations allow structural flexibility in binding with UBDs thereby inducing unique responses. One of the well-known but poorly understood UBD-Ub interaction is the recognition of K6 polyubiquitin by the ubiquitin-associated (UBA) domain of UBXN1 in the BRCA-mediated DNA repair pathway. Using our synthetic 15N-labeled diUbs, we establish here how a C-terminally extended UBA domain of UBXN1 confers specificity to K6 diUb while the non-extended version of the domain does not show any linkage preference. We show that the two distinct conformations of K6 diUb that exist in solution converge into a single conformation upon binding to this extended form of the UBA domain of the UBXN1 protein. It is likely that more of such extended UBA domains exist in nature and can contribute to linkage-specificity in Ub signaling. The isotopically labeled diUb compounds described here and the use of NMR to study their interactions with relevant partner molecules will help accelerate our understanding of Ub signaling pathways.
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Affiliation(s)
- Dharjath Shahul Hameed
- Department of Cell Biology II, The Netherlands Cancer Institute, Amsterdam, Netherlands.,Department of Cell and Chemical Biology, Oncode Institute, Leiden University Medical Centre, Leiden, Netherlands
| | - Gabrielle B A van Tilburg
- Department of Cell Biology II, The Netherlands Cancer Institute, Amsterdam, Netherlands.,Department of Cell and Chemical Biology, Oncode Institute, Leiden University Medical Centre, Leiden, Netherlands
| | - Remco Merkx
- Department of Cell Biology II, The Netherlands Cancer Institute, Amsterdam, Netherlands
| | - Dennis Flierman
- Department of Cell Biology II, The Netherlands Cancer Institute, Amsterdam, Netherlands.,Department of Cell and Chemical Biology, Oncode Institute, Leiden University Medical Centre, Leiden, Netherlands
| | - Hans Wienk
- NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, Netherlands
| | - Farid El Oualid
- Department of Cell Biology II, The Netherlands Cancer Institute, Amsterdam, Netherlands.,UbiQ Bio BV, Amsterdam, Netherlands
| | - Kay Hofmann
- Institute for Genetics, University of Cologne, Cologne, Germany
| | - Rolf Boelens
- NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, Netherlands
| | - Huib Ovaa
- Department of Cell Biology II, The Netherlands Cancer Institute, Amsterdam, Netherlands.,Department of Cell and Chemical Biology, Oncode Institute, Leiden University Medical Centre, Leiden, Netherlands
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29
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Abstract
Alzheimer's disease (AD) is the most common form of dementia, most prevalent in the elderly population and has a significant impact on individuals and their family as well as the health care system and the economy. While the number of patients affected by various forms of dementia including AD is on the increase, there is currently no cure. Although genome-wide association studies have identified genetic markers for familial AD, the molecular mechanisms underlying the initiation and development of both familial and sporadic AD remain poorly understood. Most neurodegenerative diseases and in particular those associated with dementia have been defined as proteinopathies due to the presence of intra- and/or extracellular protein aggregates in the brain of affected individuals. Although loss of proteostasis in AD has been known for decades, it is only in recent years that we have come to appreciate the role of ubiquitin-dependent mechanisms in brain homeostasis and in brain diseases. Ubiquitin is a highly versatile post-translational modification which regulates many aspects of protein fate and function, including protein degradation by the Ubiquitin-Proteasome System (UPS), autophagy-mediated removal of damaged organelles and proteins, lysosomal turnover of membrane proteins and of extracellular molecules brought inside the cell through endocytosis. Amyloid-β (Aβ) fragments as well as hyperphosphorylation of Tau are hallmarks of AD, and these are found in extracellular plaques and intracellular fibrils in the brain of individuals with AD, respectively. Yet, whether it is the oligomeric or the soluble species of Aβ and Tau that mediate toxicity is still unclear. These proteins impact on mitochondrial energy metabolism, inflammation, as well as a number of housekeeping processes including protein degradation through the UPS and autophagy. In this chapter, we will discuss the role of ubiquitin in neuronal homeostasis as well as in AD; summarise crosstalks between the enzymes that regulate protein ubiquitination and the toxic proteins Tau and Aβ; highlight emerging molecular mechanisms in AD as well as future strategies which aim to exploit the ubiquitin system as a source for next-generation therapeutics.
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30
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Wang K, Deshaies RJ, Liu X. Assembly and Regulation of CRL Ubiquitin Ligases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1217:33-46. [DOI: 10.1007/978-981-15-1025-0_3] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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31
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A negative feedback mechanism links UBC gene expression to ubiquitin levels by affecting RNA splicing rather than transcription. Sci Rep 2019; 9:18556. [PMID: 31811203 PMCID: PMC6898720 DOI: 10.1038/s41598-019-54973-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 11/20/2019] [Indexed: 12/16/2022] Open
Abstract
UBC gene plays a critical role in maintaining ubiquitin (Ub) homeostasis. It is upregulated under stress conditions, and herein we report that it is downregulated upon Ub overexpression. Downregulation occurs in a dose-dependent manner, suggesting the existence of a fine-tuned Ub sensing mechanism. This “sensor” requires a conjugation competent ubiquitin to detect Ub levels. Searching the sensor among the transcription factors involved in basal and stress-induced UBC gene expression was unsuccessful. Neither HSF1 and HSF2, nor Sp1 and YY1 are affected by the increased Ub levels. Moreover, mutagenesis of their binding sites in the UBC promoter-driven reporter constructs does not impair the downmodulation effect. Epigenetic studies show that H2A and H2B ubiquitination within the UBC promoter region is unchanged upon ubiquitin overexpression. Noteworthy, quantification of nascent RNA molecules excludes that the downmodulation arises in the transcription initiation step, rather pointing towards a post-transcriptional mechanism. Indeed, a significantly higher fraction of unspliced UBC mRNA is detected in ubiquitin overexpressing cells, compared to empty vector transfected cells. Our findings suggest how increasing cellular ubiquitin levels may control the expression of UBC gene by negatively affecting the splicing of its pre-mRNA, providing a straightforward feedback strategy for the homeostatic control of ubiquitin pools.
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32
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Heyden M. Heterogeneity of water structure and dynamics at the protein-water interface. J Chem Phys 2019; 150:094701. [PMID: 30849897 DOI: 10.1063/1.5081739] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
In this molecular dynamics simulation study, we analyze the local structural and dynamic properties of water hydrating the protein ubiquitin on a spatial grid with 1 Å resolution. This allows for insights into the spatial distribution of water number densities, molecular orientations, translations, and rotations as a function of distance from the protein surface. Water molecule orientations follow a heterogeneous distribution with preferred local orientations of water dipoles and O-H bond vectors up to 10-15 Å distances from the protein, while local variations of the water number density converge to homogeneous bulk-like values within less than 8 Å. Interestingly, we find that the long-ranged orientational structure of water does not impact either the translational or rotational dynamics of water. Instead, heterogeneous distributions of local dynamical parameters and averaged dynamical retardation factors are only found close to the protein surface and follow a distance dependence comparable to heterogeneities in the local water number density. This study shows that the formation of nanodomains of preferred water orientations far from the protein does not significantly impact dynamical processes probed as a non-local average in most experiments.
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Affiliation(s)
- Matthias Heyden
- School of Molecular Sciences and Center for Biological Physics, Arizona State University, Tempe, Arizona 85287-1604, USA
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33
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Nguyen T, Ho M, Kim K, Yun SI, Mizar P, Easton JW, Lee SS, Kim KK. Suppression of the Ubiquitin Pathway by Small Molecule Binding to Ubiquitin Enhances Doxorubicin Sensitivity of the Cancer Cells. Molecules 2019; 24:molecules24061073. [PMID: 30893775 PMCID: PMC6471062 DOI: 10.3390/molecules24061073] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 03/13/2019] [Accepted: 03/14/2019] [Indexed: 11/19/2022] Open
Abstract
Development of inhibitors for ubiquitin pathway has been suggested as a promising strategy to treat several types of cancers, which has been showcased by recent success of a series of novel anticancer drugs based on inhibition of ubiquitin pathways. Although the druggability of enzymes in ubiquitin pathways has been demonstrated, ubiquitin itself, the main agent of the pathway, has not been targeted. Whereas conventional enzyme inhibitors are used to silence the ubiquitination or reverse it, they cannot disrupt the binding activity of ubiquitin. Herein, we report that the scaffolds of sulfonated aryl diazo compounds, particularly Congo red, could disrupt the binding activity of ubiquitin, resulting in the activity equivalent to inhibition of ubiquitination. NMR mapping assay demonstrated that the chemical directly binds to the recognition site for ubiquitin processing enzymes on the surface of ubiquitin, and thereby blocks the binding of ubiquitin to its cognate receptors. As a proof of concept for the druggability of the ubiquitin molecule, we demonstrated that Congo red acted as an intracellular inhibitor of ubiquitin recognition and binding, which led to inhibition of ubiquitination, and thereby, could be used as a sensitizer for conventional anticancer drugs, doxorubicin.
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Affiliation(s)
- Thanh Nguyen
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon 440-746, Korea.
| | - Minh Ho
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon 440-746, Korea.
| | - Kyungmin Kim
- Genome Integrity and Structural Biology Laboratory, NIEHS, National Institutes of Health, Research Triangle Park, NC 27709, USA.
| | - Sun-Il Yun
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon 440-746, Korea.
| | - Pushpak Mizar
- Chemistry, Faculty of Engineering & Physical Sciences, University of Southampton, Highfield, Southampton SO17 1BJ, UK.
| | - James W Easton
- Chemistry, Faculty of Engineering & Physical Sciences, University of Southampton, Highfield, Southampton SO17 1BJ, UK.
| | - Seung Seo Lee
- Chemistry, Faculty of Engineering & Physical Sciences, University of Southampton, Highfield, Southampton SO17 1BJ, UK.
| | - Kyeong Kyu Kim
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon 440-746, Korea.
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34
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Ohtake F, Tsuchiya H, Tanaka K, Saeki Y. Methods to measure ubiquitin chain length and linkage. Methods Enzymol 2019; 618:105-133. [DOI: 10.1016/bs.mie.2018.12.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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35
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Schwerter D, Grimm I, Girzalsky W, Erdmann R. Receptor recognition by the peroxisomal AAA complex depends on the presence of the ubiquitin moiety and is mediated by Pex1p. J Biol Chem 2018; 293:15458-15470. [PMID: 30097517 DOI: 10.1074/jbc.ra118.003936] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Revised: 07/23/2018] [Indexed: 01/14/2023] Open
Abstract
The receptor cycle of type I peroxisomal matrix protein import is completed by ubiquitination of the membrane-bound peroxisome biogenesis factor 5 (Pex5p) and its subsequent export back to the cytosol. The receptor export is the only ATP-dependent step of the whole process and is facilitated by two members of the AAA family of proteins (ATPases associated with various cellular activities), namely Pex1p and Pex6p. To gain further insight into substrate recognition by the AAA complex, we generated an N-terminally linked ubiquitin-Pex5p fusion protein. This fusion protein displayed biological activity because it is able to functionally complement a PEX5-deletion in Saccharomyces cerevisiae. In vitro assays revealed its interaction at WT level with the native cargo protein Pcs60p and Pex14p, a constituent of the receptor docking complex. We also demonstrate in vitro deubiquitination by the deubiquitinating enzyme Ubp15p. In vitro pulldown assays and cross-linking studies demonstrate that Pex5p recognition by the AAA complex depends on the presence of the ubiquitin moiety and is mediated by Pex1p.
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Affiliation(s)
- Daniel Schwerter
- From the Institute of Biochemistry and Pathobiochemistry, Faculty of Medicine, Systems Biochemistry, Ruhr-University Bochum, D-44780 Bochum, Germany
| | - Immanuel Grimm
- From the Institute of Biochemistry and Pathobiochemistry, Faculty of Medicine, Systems Biochemistry, Ruhr-University Bochum, D-44780 Bochum, Germany
| | - Wolfgang Girzalsky
- From the Institute of Biochemistry and Pathobiochemistry, Faculty of Medicine, Systems Biochemistry, Ruhr-University Bochum, D-44780 Bochum, Germany
| | - Ralf Erdmann
- From the Institute of Biochemistry and Pathobiochemistry, Faculty of Medicine, Systems Biochemistry, Ruhr-University Bochum, D-44780 Bochum, Germany
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36
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Yadav U, Arya R, Kundu S, Sundd M. The “Recognition Helix” of the Type II Acyl Carrier Protein (ACP) Utilizes a “Ubiquitin Interacting Motif (UIM)”-like Surface To Bind Its Partners. Biochemistry 2018; 57:3690-3701. [DOI: 10.1021/acs.biochem.8b00220] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Usha Yadav
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110 067, India
| | - Richa Arya
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi 110 021, India
| | - Suman Kundu
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi 110 021, India
| | - Monica Sundd
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110 067, India
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37
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Lee E, Choi JH, Cho M. The effect of Hofmeister anions on water structure at protein surfaces. Phys Chem Chem Phys 2018; 19:20008-20015. [PMID: 28722047 DOI: 10.1039/c7cp02826a] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
To understand the effects of specific ions on protein-water interactions and the thermodynamic stability of proteins in salt solutions, we use a molecular dynamics (MD) simulation to examine the water structure, orientational distribution, and dynamics near the surface of ubiquitin. In particular, we consider NaCl, NaBF4, NaSCN, and NaClO4 salt solutions containing ubiquitin, where the anions of the latter three salts are well-known chaotropic ions in the Hofmiester anion series. The number of hydrogen bonds (H-bonds) per water molecule is found to decrease significantly at the ubiquitin-water interface, indicating a significant disruption of the water H-bonding network. The distribution of the water H-bond numbers near the protein surface is modulated by dissolved ions, and the extent of the ion effect on the H-bonding network structure follows the order of the Hofmeister anion series, while there are no specific ion effects on water properties at distances larger than 5 Å from the protein surface. From detailed analyses of the surface area, volume, and root-mean-square deviation (RMSD) of ubiquitin, we show that changes in the properties of the protein could originate from the disruption of the water H-bond network induced by ions with a higher affinity for the protein surface instead of direct protein residue-ion interactions. An interesting observation made here is that the orientational distribution of water molecules at the protein-water interface is close to random, but there is a slight preference for interfacial water molecules with a straddle structure within 2.5 Å of the protein surface, where one of the two OH groups points away from the protein surface and the other points toward the surface. In addition, comparing the MD simulation results for ubiquitin solutions with dissolved NaSCN and KSCN, we show that Na+ affects the water H-bonding structure at the protein surface more than K+. It is clear that the H-bonding network structure of water more than one water layer away from the protein surface is not distinguishably different from that of neat water. We thus anticipate that the present work will provide insights into the scale of specific ion effects on the H-bonding structure and orientational distribution of water in the vicinity of protein surfaces in aqueous solutions.
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Affiliation(s)
- Euihyun Lee
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Korea University, Seoul 02841, Republic of Korea.
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38
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Swaim CD, Scott AF, Canadeo LA, Huibregtse JM. Extracellular ISG15 Signals Cytokine Secretion through the LFA-1 Integrin Receptor. Mol Cell 2017; 68:581-590.e5. [PMID: 29100055 DOI: 10.1016/j.molcel.2017.10.003] [Citation(s) in RCA: 138] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 07/31/2017] [Accepted: 10/03/2017] [Indexed: 12/30/2022]
Abstract
ISG15 is a ubiquitin-like protein that functions in innate immunity both as an intracellular protein modifier and as an extracellular signaling molecule that stimulates IFN-γ secretion. The extracellular function, important for resistance to mycobacterial disease, has remained biochemically uncharacterized. We have established an NK-92 cell-based assay for IFN-γ release, identified residues critical for ISG15 signaling, and identified the cell surface receptor as LFA-1 (CD11a/CD18; αLβ2 integrin). LFA-1 inhibition blocked IFN-γ secretion, splenocytes from CD11a-/- mice did not respond to ISG15, and ISG15 bound directly to the αI domain of CD11a in vitro. ISG15 also enhanced secretion of IL-10, indicating a broader role for ISG15 in cytokine signaling. ISG15 engagement of LFA-1 led to the activation of SRC family kinases (SFKs) and SFK inhibition blocked cytokine secretion. These findings establish the molecular basis of the extracellular function of ISG15 and the initial outside-in signaling events that drive ISG15-dependent cytokine secretion.
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Affiliation(s)
- Caleb D Swaim
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA
| | - Ariella F Scott
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA
| | - Larissa A Canadeo
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA
| | - Jon M Huibregtse
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA.
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39
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Gladkova C, Schubert AF, Wagstaff JL, Pruneda JN, Freund SM, Komander D. An invisible ubiquitin conformation is required for efficient phosphorylation by PINK1. EMBO J 2017; 36:3555-3572. [PMID: 29133469 PMCID: PMC5730886 DOI: 10.15252/embj.201797876] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 10/16/2017] [Accepted: 10/18/2017] [Indexed: 11/09/2022] Open
Abstract
The Ser/Thr protein kinase PINK1 phosphorylates the well-folded, globular protein ubiquitin (Ub) at a relatively protected site, Ser65. We previously showed that Ser65 phosphorylation results in a conformational change in which Ub adopts a dynamic equilibrium between the known, common Ub conformation and a distinct, second conformation wherein the last β-strand is retracted to extend the Ser65 loop and shorten the C-terminal tail. We show using chemical exchange saturation transfer (CEST) nuclear magnetic resonance experiments that a similar, C-terminally retracted (Ub-CR) conformation also exists at low population in wild-type Ub. Point mutations in the moving β5 and neighbouring β-strands shift the Ub/Ub-CR equilibrium. This enabled functional studies of the two states, and we show that while the Ub-CR conformation is defective for conjugation, it demonstrates improved binding to PINK1 through its extended Ser65 loop, and is a superior PINK1 substrate. Together our data suggest that PINK1 utilises a lowly populated yet more suitable Ub-CR conformation of Ub for efficient phosphorylation. Our findings could be relevant for many kinases that phosphorylate residues in folded protein domains.
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Affiliation(s)
| | | | - Jane L Wagstaff
- Medical Research Council Laboratory of Molecular Biology, Cambridge, UK
| | | | - Stefan Mv Freund
- Medical Research Council Laboratory of Molecular Biology, Cambridge, UK
| | - David Komander
- Medical Research Council Laboratory of Molecular Biology, Cambridge, UK
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40
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Lee S, Tumolo JM, Ehlinger AC, Jernigan KK, Qualls-Histed SJ, Hsu PC, McDonald WH, Chazin WJ, MacGurn JA. Ubiquitin turnover and endocytic trafficking in yeast are regulated by Ser57 phosphorylation of ubiquitin. eLife 2017; 6:29176. [PMID: 29130884 PMCID: PMC5706963 DOI: 10.7554/elife.29176] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 11/10/2017] [Indexed: 11/30/2022] Open
Abstract
Despite its central role in protein degradation little is known about the molecular mechanisms that sense, maintain, and regulate steady state concentration of ubiquitin in the cell. Here, we describe a novel mechanism for regulation of ubiquitin homeostasis that is mediated by phosphorylation of ubiquitin at the Ser57 position. We find that loss of Ppz phosphatase activity leads to defects in ubiquitin homeostasis that are at least partially attributable to elevated levels of Ser57 phosphorylated ubiquitin. Phosphomimetic mutation at the Ser57 position of ubiquitin conferred increased rates of endocytic trafficking and ubiquitin turnover. These phenotypes are associated with bypass of recognition by endosome-localized deubiquitylases - including Doa4 which is critical for regulation of ubiquitin recycling. Thus, ubiquitin homeostasis is significantly impacted by the rate of ubiquitin flux through the endocytic pathway and by signaling pathways that converge on ubiquitin itself to determine whether it is recycled or degraded in the vacuole.
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Affiliation(s)
- Sora Lee
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, United States
| | - Jessica M Tumolo
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, United States
| | - Aaron C Ehlinger
- Department of Biochemistry, Vanderbilt University, Nashville, United States
| | - Kristin K Jernigan
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, United States
| | - Susan J Qualls-Histed
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, United States
| | - Pi-Chiang Hsu
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, United States
| | - W Hayes McDonald
- Department of Biochemistry, Vanderbilt University, Nashville, United States.,Mass Spectrometry Research Center, Vanderbilt University, Nashville, United States
| | - Walter J Chazin
- Department of Biochemistry, Vanderbilt University, Nashville, United States
| | - Jason A MacGurn
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, United States
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41
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Functional analysis of Cullin 3 E3 ligases in tumorigenesis. Biochim Biophys Acta Rev Cancer 2017; 1869:11-28. [PMID: 29128526 DOI: 10.1016/j.bbcan.2017.11.001] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 11/06/2017] [Accepted: 11/06/2017] [Indexed: 12/14/2022]
Abstract
Cullin 3-RING ligases (CRL3) play pivotal roles in the regulation of various physiological and pathological processes, including neoplastic events. The substrate adaptors of CRL3 typically contain a BTB domain that mediates the interaction between Cullin 3 and target substrates to promote their ubiquitination and subsequent degradation. The biological implications of CRL3 adaptor proteins have been well described where they have been found to play a role as either an oncogene, tumor suppressor, or can mediate either of these effects in a context-dependent manner. Among the extensively studied CRL3-based E3 ligases, the role of the adaptor protein SPOP (speckle type BTB/POZ protein) in tumorigenesis appears to be tissue or cellular context dependent. Specifically, SPOP acts as a tumor suppressor via destabilizing downstream oncoproteins in many malignancies, especially in prostate cancer. However, SPOP has largely an oncogenic role in kidney cancer. Keap1, another well-characterized CRL3 adaptor protein, likely serves as a tumor suppressor within diverse malignancies, mainly due to its specific turnover of its downstream oncogenic substrate, NRF2 (nuclear factor erythroid 2-related factor 2). In accordance with the physiological role the various CRL3 adaptors exhibit, several pharmacological agents have been developed to disrupt its E3 ligase activity, therefore blocking its potential oncogenic activity to mitigate tumorigenesis.
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42
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Mechanism and disease association of E2-conjugating enzymes: lessons from UBE2T and UBE2L3. Biochem J 2017; 473:3401-3419. [PMID: 27729585 PMCID: PMC5095918 DOI: 10.1042/bcj20160028] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 08/09/2016] [Indexed: 02/07/2023]
Abstract
Ubiquitin signalling is a fundamental eukaryotic regulatory system, controlling diverse cellular functions. A cascade of E1, E2, and E3 enzymes is required for assembly of distinct signals, whereas an array of deubiquitinases and ubiquitin-binding modules edit, remove, and translate the signals. In the centre of this cascade sits the E2-conjugating enzyme, relaying activated ubiquitin from the E1 activating enzyme to the substrate, usually via an E3 ubiquitin ligase. Many disease states are associated with dysfunction of ubiquitin signalling, with the E3s being a particular focus. However, recent evidence demonstrates that mutations or impairment of the E2s can lead to severe disease states, including chromosome instability syndromes, cancer predisposition, and immunological disorders. Given their relevance to diseases, E2s may represent an important class of therapeutic targets. In the present study, we review the current understanding of the mechanism of this important family of enzymes, and the role of selected E2s in disease.
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43
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Saeki Y. Ubiquitin recognition by the proteasome. J Biochem 2017; 161:113-124. [PMID: 28069863 DOI: 10.1093/jb/mvw091] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 11/21/2016] [Indexed: 12/14/2022] Open
Abstract
The 26S proteasome is a 2.5-MDa complex responsible for the selective, ATP-dependent degradation of ubiquitylated proteins in eukaryotic cells. Substrates in hundreds cellular pathways are timely ubiquitylated and converged to the proteasome by direct recognition or by multiple shuttle factors. Engagement of substrate protein triggers conformational changes of the proteasome, which drive substrate unfolding, deubiquitylation and translocation of substrates to proteolytic sites. Recent studies have challenged the previous paradigm that Lys48-linked tetraubiquitin is a minimal degradation signal: in addition, monoubiquitylation or multiple short ubiquitylations can serve as the targeting signal for proteasomal degradation. In this review, I highlight recent advances in our understanding of the proteasome structure, the ubiquitin topology in proteasome targeting, and the cellular factors that regulate proteasomal degradation.
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Affiliation(s)
- Yasushi Saeki
- Laboratory of Protein Metabolism, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan
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44
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Doshi A, Sharma M, Prabha CR. Structural changes induced by L50P and I61T single mutations of ubiquitin affect cell cycle progression while impairing its regulatory and degradative functions in Saccharomyces cerevisiae. Int J Biol Macromol 2017; 99:128-140. [DOI: 10.1016/j.ijbiomac.2017.02.053] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2016] [Revised: 02/07/2017] [Accepted: 02/13/2017] [Indexed: 12/23/2022]
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45
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Abstract
The ubiquitin proteasome system controls the concentrations of regulatory proteins and removes damaged and misfolded proteins from cells. Proteins are targeted to the protease at the center of this system, the proteasome, by ubiquitin tags, but ubiquitin is also used as a signal in other cellular processes. Specificity is conferred by the size and structure of the ubiquitin tags, which are recognized by receptors associated with the different cellular processes. However, the ubiquitin code remains ambiguous, and the same ubiquitin tag can target different proteins to different fates. After binding substrate protein at the ubiquitin tag, the proteasome initiates degradation at a disordered region in the substrate. The proteasome has pronounced preferences for the initiation site, and its recognition represents a second component of the degradation signal.
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Affiliation(s)
- Houqing Yu
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712;
| | - Andreas Matouschek
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712;
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46
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Newman HA, Meluh PB, Lu J, Vidal J, Carson C, Lagesse E, Gray JJ, Boeke JD, Matunis MJ. A high throughput mutagenic analysis of yeast sumo structure and function. PLoS Genet 2017; 13:e1006612. [PMID: 28166236 PMCID: PMC5319795 DOI: 10.1371/journal.pgen.1006612] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 02/21/2017] [Accepted: 01/31/2017] [Indexed: 11/18/2022] Open
Abstract
Sumoylation regulates a wide range of essential cellular functions through diverse mechanisms that remain to be fully understood. Using S. cerevisiae, a model organism with a single essential SUMO gene (SMT3), we developed a library of >250 mutant strains with single or multiple amino acid substitutions of surface or core residues in the Smt3 protein. By screening this library using plate-based assays, we have generated a comprehensive structure-function based map of Smt3, revealing essential amino acid residues and residues critical for function under a variety of genotoxic and proteotoxic stress conditions. Functionally important residues mapped to surfaces affecting Smt3 precursor processing and deconjugation from protein substrates, covalent conjugation to protein substrates, and non-covalent interactions with E3 ligases and downstream effector proteins containing SUMO-interacting motifs. Lysine residues potentially involved in formation of polymeric chains were also investigated, revealing critical roles for polymeric chains, but redundancy in specific chain linkages. Collectively, our findings provide important insights into the molecular basis of signaling through sumoylation. Moreover, the library of Smt3 mutants represents a valuable resource for further exploring the functions of sumoylation in cellular stress response and other SUMO-dependent pathways.
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Affiliation(s)
- Heather A. Newman
- Department of Biochemistry and Molecular Biology, Johns Hopkins University, Bloomberg School of Public Health, Baltimore, MD, United States of America
| | - Pamela B. Meluh
- High Throughput Biology Center and Department of Molecular Biology and Genetics, Johns Hopkins University, School of Medicine, Baltimore, MD, United States of America
| | - Jian Lu
- Department of Biochemistry and Molecular Biology, Johns Hopkins University, Bloomberg School of Public Health, Baltimore, MD, United States of America
| | - Jeremy Vidal
- Department of Biochemistry and Molecular Biology, Johns Hopkins University, Bloomberg School of Public Health, Baltimore, MD, United States of America
| | - Caryn Carson
- Department of Biochemistry and Molecular Biology, Johns Hopkins University, Bloomberg School of Public Health, Baltimore, MD, United States of America
| | - Elizabeth Lagesse
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, United States of America
| | - Jeffrey J. Gray
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, United States of America
| | - Jef D. Boeke
- High Throughput Biology Center and Department of Molecular Biology and Genetics, Johns Hopkins University, School of Medicine, Baltimore, MD, United States of America
| | - Michael J. Matunis
- Department of Biochemistry and Molecular Biology, Johns Hopkins University, Bloomberg School of Public Health, Baltimore, MD, United States of America
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47
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Ubiquitin utilizes an acidic surface patch to alter chromatin structure. Nat Chem Biol 2016; 13:105-110. [PMID: 27870837 PMCID: PMC5161692 DOI: 10.1038/nchembio.2235] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 09/07/2016] [Indexed: 02/06/2023]
Abstract
Ubiquitylation of histone H2B, associated with gene activation, leads to chromatin decompaction through an unknown mechanism. We used a hydrogen-deuterium exchange strategy coupled with nuclear magnetic resonance spectroscopy to map the ubiquitin surface responsible for its structural effects on chromatin. Our studies revealed that a previously uncharacterized acidic patch on ubiquitin comprising residues Glu16 and Glu18 is essential for decompaction. These residues mediate promiscuous electrostatic interactions with the basic histone proteins, potentially positioning the ubiquitin moiety as a dynamic “wedge” that prevents the intimate association of neighboring nucleosomes. Using two independent cross-linking strategies and an oligomerization assay, we also showed that ubiquitin-ubiquitin contacts occur in the chromatin environment and are important for the solubilization of the chromatin polymers. Our work highlights a novel, chromatin-related aspect of the “ubiquitin code”, and sheds light on how the information rich ubiquitin modification can orchestrate different biochemical outcomes using different surface features.
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48
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Abstract
Post-translational modification (PTM) of proteins by ubiquitination is an essential cellular regulatory process. Such regulation drives the cell cycle and cell division, signalling and secretory pathways, DNA replication and repair processes and protein quality control and degradation pathways. A huge range of ubiquitin signals can be generated depending on the specificity and catalytic activity of the enzymes required for attachment of ubiquitin to a given target. As a consequence of its importance to eukaryotic life, dysfunction in the ubiquitin system leads to many disease states, including cancers and neurodegeneration. This review takes a retrospective look at our progress in understanding the molecular mechanisms that govern the specificity of ubiquitin conjugation.
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49
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The K48-K63 Branched Ubiquitin Chain Regulates NF-κB Signaling. Mol Cell 2016; 64:251-266. [DOI: 10.1016/j.molcel.2016.09.014] [Citation(s) in RCA: 180] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 08/05/2016] [Accepted: 09/09/2016] [Indexed: 12/12/2022]
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50
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Rao T, Gao R, Takada S, Al Abo M, Chen X, Walters KJ, Pommier Y, Aihara H. Novel TDP2-ubiquitin interactions and their importance for the repair of topoisomerase II-mediated DNA damage. Nucleic Acids Res 2016; 44:10201-10215. [PMID: 27543075 PMCID: PMC5137425 DOI: 10.1093/nar/gkw719] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 07/30/2016] [Accepted: 08/08/2016] [Indexed: 12/22/2022] Open
Abstract
Tyrosyl DNA phosphodiesterase 2 (TDP2) is a multifunctional protein implicated in DNA repair, signal transduction and transcriptional regulation. In its DNA repair role, TDP2 safeguards genome integrity by hydrolyzing 5′-tyrosyl DNA adducts formed by abortive topoisomerase II (Top2) cleavage complexes to allow error-free repair of DNA double-strand breaks, thereby conferring cellular resistance against Top2 poisons. TDP2 consists of a C-terminal catalytic domain responsible for its phosphodiesterase activity, and a functionally uncharacterized N-terminal region. Here, we demonstrate that this N-terminal region contains a ubiquitin (Ub)-associated (UBA) domain capable of binding multiple forms of Ub with distinct modes of interactions and preference for either K48- or K63-linked polyUbs over monoUb. The structure of TDP2 UBA bound to monoUb shows a canonical mode of UBA-Ub interaction. However, the absence of the highly conserved MGF motif and the presence of a fourth α-helix make TDP2 UBA distinct from other known UBAs. Mutations in the TDP2 UBA-Ub binding interface do not affect nuclear import of TDP2, but severely compromise its ability to repair Top2-mediated DNA damage, thus establishing the importance of the TDP2 UBA–Ub interaction in DNA repair. The differential binding to multiple Ub forms could be important for responding to DNA damage signals under different contexts or to support the multi-functionality of TDP2.
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Affiliation(s)
- Timsi Rao
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Rui Gao
- Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Saeko Takada
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Muthana Al Abo
- Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Xiang Chen
- Protein Processing Section, Structural Biophysics Laboratory, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
| | - Kylie J Walters
- Protein Processing Section, Structural Biophysics Laboratory, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
| | - Yves Pommier
- Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Hideki Aihara
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
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