1
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Torrado C, Ashton NW, D'Andrea AD, Yap TA. USP1 inhibition: A journey from target discovery to clinical translation. Pharmacol Ther 2025; 271:108865. [PMID: 40274197 DOI: 10.1016/j.pharmthera.2025.108865] [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: 01/23/2025] [Revised: 04/04/2025] [Accepted: 04/20/2025] [Indexed: 04/26/2025]
Abstract
Ubiquitin-specific protease 1 (USP1) is a deubiquitinating enzyme involved in the DNA damage response. Upon DNA damage, USP1 stabilizes replication forks by removing monoubiquitin from PCNA and FANCD2-FANCI, thereby catalyzing critical final steps in translesion synthesis and interstrand crosslink (ICL) repair. This function is particularly crucial in BRCA1 mutant cancers, where the homologous recombination pathway is compromised, leading tumors to rely on USP1 for effective repair. USP1 is also overexpressed in BRCA1 mutant cancers, as well as other tumor types. Preclinical studies have demonstrated that knockout of USP1 is synthetically lethal in tumors with biallelic BRCA1 mutations, and this relationship is enhanced by combination with PARP inhibitors. Newly developed USP1 inhibitors have confirmed this synthetic lethality in BRCA1-deficient tumor cells. Moreover, these drugs have the potential for resensitizing platinum-resistant tumors. Currently, potent and specific USP1 inhibitors are undergoing evaluation in phase I clinical trials. RO7623066 (KSQ-4279) reported an acceptable safety profile during a phase I dose escalation study, with anemia being the most common side effect, and demonstrated robust pharmacokinetic, pharmacodynamic, and clinical activity. Other USP1 inhibitors, including SIM0501, XL309-101, and HSK39775, are currently in early clinical development. In this review, we provide an overview of the molecular function of USP1 and its importance as a therapeutic target in oncology, before focusing on the current state of preclinical and clinical development of USP1 inhibitors.
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Affiliation(s)
- Carlos Torrado
- University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Nicholas W Ashton
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Alan D D'Andrea
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, MA, USA; Center for DNA Damage and Repair, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Timothy A Yap
- University of Texas MD Anderson Cancer Center, Houston, TX, USA.
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2
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Xiao Z, Gavriil ES, Cao F, Zhang X, Li SX, Kotelnikov S, Michalska P, Marte F, Huang C, Lu Y, Zhang Y, Bernardini E, Kozakov D, Tate EW. Identification of Actionable Targeted Protein Degradation Effector Sites through Site-Specific Ligand Incorporation-Induced Proximity (SLIP). J Am Chem Soc 2025. [PMID: 40493711 DOI: 10.1021/jacs.5c01420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/18/2025]
Abstract
Targeted protein degradation (TPD) is a rapidly emerging and potentially transformative therapeutic modality. However, the large majority of >600 known ubiquitin ligases have yet to be exploited as TPD effectors by proteolysis-targeting chimeras (PROTACs) or molecular glue degraders (MGDs). We report here a chemical-genetic platform, Site-specific Ligand Incorporation-induced Proximity (SLIP), to identify actionable ("PROTACable") sites on any potential effector protein in intact cells. SLIP uses genetic code expansion to encode copper-free "click" ligation at a specific effector site in intact cells, enabling the in situ formation of a covalent PROTAC-effector conjugate against a target protein of interest. Modification at actionable effector sites drives degradation of the targeted protein, establishing the potential of these sites for TPD. Using SLIP, we systematically screened dozens of sites across E3 ligases and E2 enzymes from diverse classes, identifying multiple novel potentially PROTACable effector sites which are competent for TPD. SLIP adds a powerful approach to the proximity-induced pharmacology (PIP) toolbox, enabling future effector ligand discovery to fully enable TPD and other emerging PIP modalities.
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Affiliation(s)
- Zhangping Xiao
- Department of Chemistry, Imperial College London, 82 Wood Lane, London W12 0BZ, U.K
| | - Efthymios S Gavriil
- Department of Chemistry, Imperial College London, 82 Wood Lane, London W12 0BZ, U.K
| | - Fangyuan Cao
- Department of Chemistry, Imperial College London, 82 Wood Lane, London W12 0BZ, U.K
| | - Xinyue Zhang
- Department of Chemistry, Imperial College London, 82 Wood Lane, London W12 0BZ, U.K
| | - Stan Xiaogang Li
- Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, New York 11794, United States
- Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, New York 11794, United States
| | - Sergei Kotelnikov
- Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, New York 11794, United States
- Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, New York 11794, United States
| | - Patrycja Michalska
- Department of Chemistry, Imperial College London, 82 Wood Lane, London W12 0BZ, U.K
| | - Friederike Marte
- Department of Chemistry, Imperial College London, 82 Wood Lane, London W12 0BZ, U.K
| | - Chloe Huang
- Department of Chemistry, Imperial College London, 82 Wood Lane, London W12 0BZ, U.K
| | - Yudi Lu
- Department of Chemistry, Imperial College London, 82 Wood Lane, London W12 0BZ, U.K
| | - Yunxuan Zhang
- Department of Chemistry, Imperial College London, 82 Wood Lane, London W12 0BZ, U.K
| | - Erika Bernardini
- Department of Chemistry, Imperial College London, 82 Wood Lane, London W12 0BZ, U.K
| | - Dima Kozakov
- Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, New York 11794, United States
- Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, New York 11794, United States
| | - Edward W Tate
- Department of Chemistry, Imperial College London, 82 Wood Lane, London W12 0BZ, U.K
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3
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Parashar S, Kaushik A, Ambasta RK, Kumar P. E2 conjugating enzymes: A silent but crucial player in ubiquitin biology. Ageing Res Rev 2025; 108:102740. [PMID: 40194666 DOI: 10.1016/j.arr.2025.102740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2025] [Revised: 03/14/2025] [Accepted: 03/19/2025] [Indexed: 04/09/2025]
Abstract
E2 conjugating enzymes serve as the linchpin of the Ubiquitin-Proteasome System (UPS), facilitating ubiquitin (Ub) transfer to substrate proteins and regulating diverse processes critical to cellular homeostasis. The interaction of E2s with E1 activating enzymes and E3 ligases singularly positions them as middlemen of the ubiquitin machinery that guides protein turnover. Structural determinants of E2 enzymes play a pivotal role in these interactions, enabling precise ubiquitin transfer and substrate specificity. Regulation of E2 enzymes is tightly controlled through mechanisms such as post-translational modifications (PTMs), allosteric control, and gene expression modulation. Specific residues that undergo PTMs highlight their impact on E2 function and their role in ubiquitin dynamics. E2 enzymes also cooperate with deubiquitinases (DUBs) to maintain proteostasis. Design of small molecule inhibitors to modulate E2 activity is emerging as promising avenue to restrict ubiquitination as a potential therapeutic intervention. Additionally, E2 enzymes have been implicated in the pathogenesis and progression of neurodegenerative disorders (NDDs), where their dysfunction contributes to disease mechanisms. In summary, examining E2 enzymes from structural and functional perspectives offers potential to advance our understanding of cellular processes and assist in discovery of new therapeutic targets.
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Affiliation(s)
- Somya Parashar
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi Technological University (Formerly Delhi College of Engineering), Shahbad Daulatpur, Bawana Road, Delhi 110042, India
| | - Aastha Kaushik
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi Technological University (Formerly Delhi College of Engineering), Shahbad Daulatpur, Bawana Road, Delhi 110042, India
| | - Rashmi K Ambasta
- Department of Medicine, Vanderbilt University Medical Center (VUMC), Nashville, TN, USA
| | - Pravir Kumar
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi Technological University (Formerly Delhi College of Engineering), Shahbad Daulatpur, Bawana Road, Delhi 110042, India.
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4
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Warner K, Hunkeler M, Baek K, Schmoker A, Roy Burman SS, Overwijn D, Jin C, Donovan KA, Fischer ES. Structural ubiquitin contributes to K48 linkage specificity of the HECT ligase Tom1. Cell Rep 2025; 44:115688. [PMID: 40359109 DOI: 10.1016/j.celrep.2025.115688] [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: 10/06/2024] [Revised: 02/16/2025] [Accepted: 04/18/2025] [Indexed: 05/15/2025] Open
Abstract
Homologous to E6AP C terminus (HECT) ubiquitin ligases play key roles in essential pathways such as DNA repair, cell cycle control, or protein quality control. Tom1 is one of five HECT ubiquitin E3 ligases in budding yeast S. cerevisiae and is prototypical for a ligase with pleiotropic functions such as ubiquitin chain amplification, orphan quality control, and DNA damage response. Structures of full-length HECT ligases, including the Tom1 ortholog HUWE1, have been reported, but how domains beyond the conserved catalytic module contribute to catalysis remains largely elusive. Here, through cryoelectron microscopy (cryo-EM) snapshots of Tom1 during an active ubiquitination cycle, we demonstrate that the extended domain architecture directly contributes to activity. We identify a Tom1-ubiquitin architecture during ubiquitination involving a non-canonical ubiquitin-binding site in the solenoid shape of Tom1. We demonstrate that this ubiquitin-binding site coordinates a structural ubiquitin contributing to the fidelity of K48 poly-ubiquitin chain assembly.
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Affiliation(s)
- Katrina Warner
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02215, USA
| | - Moritz Hunkeler
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02215, USA
| | - Kheewoong Baek
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02215, USA
| | - Anna Schmoker
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02215, USA
| | - Shourya S Roy Burman
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02215, USA
| | - Daan Overwijn
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | - Cyrus Jin
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02215, USA
| | - Katherine A Donovan
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02215, USA
| | - Eric S Fischer
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02215, USA.
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5
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Claustre A, Malige M, Macheton M, Combaret L, Lefai E, Fafournoux P, Taillandier D, Henri J, Polge C. Structure predictions of MuRF1-UBE2 complexes identify amino acid residues governing interaction selectivity for each MuRF1-E2 pair. FEBS J 2025; 292:2559-2577. [PMID: 39930652 PMCID: PMC12103069 DOI: 10.1111/febs.70017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2024] [Revised: 12/03/2024] [Accepted: 01/31/2025] [Indexed: 05/25/2025]
Abstract
The RING-type E3 ubiquitin-protein ligase MuRF1 (also known as TRIM63) plays an important role in skeletal muscle atrophy by targeting contractile proteins. In cellulo, MuRF1 can alternatively interact with four E2 enzymes (UBE2E1, UBE2J1, UBE2J2, or UBE2L3), suggesting different functions or targets for the four MuRF1-E2 complexes. In this article, we studied the interface of these MuRF1-UBE2 complexes based on AlphaFold2 and AlphaFold3 predictions. These predictions revealed the involvement of different residues at the interface of each complex. We confirmed this overall interface difference by the differential sensitivity of MuRF1-E2 complexes to regenerating solutions in surface plasmon resonance experiments. We further confirmed several predictions individually by affinity measurements with point-mutant E2 enzymes and truncated MuRF1. We used the interaction-induced fluorescence change approach with fluorescent MuRF1. Besides canonical E2-RING-type E3 interactions, we were able to identify selective contact points between MuRF1 and its UBE2 partners. Furthermore, in the case of the MuRF1-E2E1 pair, unlike the other MuRF1-E2 pairs, the interaction may also be governed by a domain outside the RING domain. Since the function of RING-type E3s is regulated by E2 enzymes, deciphering the mechanisms of selective recruitment of E2s by MuRF1 paves the way for the development of targeted therapeutics to fight muscle atrophy.
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Affiliation(s)
- Agnès Claustre
- Université Clermont Auvergne, INRAE, UNHClermont‐FerrandFrance
| | - Mélodie Malige
- Université Clermont Auvergne, INRAE, UNHClermont‐FerrandFrance
| | - Maëlys Macheton
- Université Clermont Auvergne, INRAE, UNHClermont‐FerrandFrance
| | - Lydie Combaret
- Université Clermont Auvergne, INRAE, UNHClermont‐FerrandFrance
| | - Etienne Lefai
- Université Clermont Auvergne, INRAE, UNHClermont‐FerrandFrance
| | | | | | - Julien Henri
- Sorbonne Université, CNRS, Laboratoire de Biologie Computationnelle et Quantitative, Institut de Biologie Paris‐Seine, UMR 7238ParisFrance
| | - Cécile Polge
- Université Clermont Auvergne, INRAE, UNHClermont‐FerrandFrance
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6
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Suresh P, Wijne C, Sun ZYJ, Becht N, Sahay I, Pishesha N, Ploegh H. A nanobody that binds to the backside of the ubiquitin conjugating enzyme Ube2G2 differentially affects interactions with its partner E3 Ligases. Commun Biol 2025; 8:614. [PMID: 40234692 PMCID: PMC12000298 DOI: 10.1038/s42003-025-08038-3] [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: 07/11/2024] [Accepted: 04/02/2025] [Indexed: 04/17/2025] Open
Abstract
Ubiquitin conjugating E2 enzymes are a set of ~40 proteins that play a central role in the ubiquitination cascade. They transfer ubiquitin from an E1 enzyme to substrates with the help of an E3 enzyme. The members of the E2 family share structural similarity in their conserved UBC fold. This complicates an assessment of the specificity of E2-E3 interactions. We identified a nanobody that binds to the 'backside' region of Ube2G2, an E2 involved in ER protein quality control. This binding does not affect ubiquitin loading but shows varying degrees of inhibition on E3-mediated ubiquitination, in the order HRD1 > CHIP >> TRC8. A naturally occurring segment that binds Ube2G2's backside, referred to as G2BR (Ube2G2 Binding Region), shows a similar inhibitory effect depending on the identity of the interacting E3. The G2BR in the Ube2G2-cognate E3 Gp78 enhances Ube2G2's activity, but its deletion results in a similar inhibition upon addition of the nanobody. Occupation of a single binding site on an E2 can thus affect its interactions with different E3s.
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Affiliation(s)
- Pavana Suresh
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
| | - Charlotte Wijne
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Zhen-Yu J Sun
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Nanette Becht
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Ishani Sahay
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Novalia Pishesha
- Division of Immunology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Hidde Ploegh
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
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7
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Lim YJ, Lee YH. Solo or in Concert: SUMOylation in Pathogenic Fungi. THE PLANT PATHOLOGY JOURNAL 2025; 41:140-152. [PMID: 40211619 PMCID: PMC11986368 DOI: 10.5423/ppj.rw.11.2024.0180] [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] [Received: 11/18/2024] [Revised: 02/27/2025] [Accepted: 03/02/2025] [Indexed: 04/14/2025]
Abstract
SUMOylation plays a pivotal role in DNA replication and repair, transcriptional stability, and stress response. Although SUMOylation is a conserved posttranslational modification (PTM) in eukaryotes, the number, type, and function of SUMOylation-associated components vary among mammals, plants, and fungi. SUMOylation shares overlapping features with ubiquitination, another well-known PTM. However, comparative studies on the interplay between these two PTMs are largely limited to yeast among fungal species. Recently, the role of SUMOylation in pathogenicity and its potential for crosstalk with ubiquitination have gained attention in fungal pathogens. In this review, we summarize recent findings on the distinct components of SUMOylation across organisms and describe its critical functions in fungal pathogens. Furthermore, we propose new research directions for SUMOylation in fungal pathogens, both independently and in coordination with other PTMs. This review aims to illuminate the potential for advancing PTM crosstalk research in fungal systems.
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Affiliation(s)
- You-Jin Lim
- Research Institute of Agriculture and Life Sciences and Department of Agricultural Biotechnology, Seoul National University, Seoul 08826, Korea
| | - Yong-Hwan Lee
- Research Institute of Agriculture and Life Sciences and Department of Agricultural Biotechnology, Seoul National University, Seoul 08826, Korea
- Interdisciplinary Program in Agricultural Genomics, Center for Fungal Genetic Resources, Plant Immunity Research Center, and Center for Plant Microbiome Research, Seoul National University, Seoul 08826, Korea
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8
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Vaziri C, Forker K, Zhang X, Wu D, Zhou P, Bowser JL. Pathological modulation of genome maintenance by cancer/testes antigens (CTAs). DNA Repair (Amst) 2025; 147:103818. [PMID: 39983270 PMCID: PMC11923853 DOI: 10.1016/j.dnarep.2025.103818] [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: 12/22/2024] [Revised: 02/07/2025] [Accepted: 02/10/2025] [Indexed: 02/23/2025]
Abstract
The Cancer Testis Antigens (CTAs) are a group of germ cell proteins that are absent from normal somatic cells yet aberrantly expressed in many cancer cells. When mis-expressed in cancer cells, many CTAs promote tumorigenic characteristics including genome instability, DNA damage tolerance and therapy resistance. Here we highlight some of the CTAs for which their roles in genome maintenance in cancer cells are well established. We consider three broad CTA categories: (1) Melanoma Antigens (MAGEs) (2) Mitotic CTAs and (3) CTAs with roles in meiotic homologous recombination. Many cancer cells rely on CTAs to tolerate intrinsic and therapy-induced genotoxic stress. Therefore, CTAs represent molecular vulnerabilities of cancer cells and may provide opportunities for therapy. Owing to their high-level expression in tumors and absence from normal somatic cells, CTA-directed therapies could have a high level of specificity and would likely be devoid of side-effect toxicity.
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Affiliation(s)
- Cyrus Vaziri
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA.
| | - Karly Forker
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Xingyuan Zhang
- Department of Biostatistics and Bioinformatics, Duke University School of Medicine, Durham, NC 27710, USA
| | - Di Wu
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA; Department of Biostatistics, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Pei Zhou
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Jessica L Bowser
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA.
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9
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Xiao Z, Gavriil ES, Cao F, Zhang X, Li SX, Kotelnikov S, Michalska P, Marte F, Huang C, Lu Y, Zhang Y, Bernardini E, Kozakov D, Tate EW. Identification of actionable targeted protein degradation effector sites through Site-specific Ligand Incorporation-induced Proximity (SLIP). BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2025:2025.02.04.636303. [PMID: 39975383 PMCID: PMC11838594 DOI: 10.1101/2025.02.04.636303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 02/21/2025]
Abstract
Targeted protein degradation (TPD) is a rapidly emerging and potentially transformative therapeutic modality. However, the large majority of >600 known ubiquitin ligases have yet to be exploited as TPD effectors by proteolysis-targeting chimeras (PROTACs) or molecular glue degraders (MGDs). We report here a chemical-genetic platform, Site-specific Ligand Incorporation-induced Proximity (SLIP), to identify actionable ("PROTACable") sites on any potential effector protein in intact cells. SLIP uses genetic code expansion (GCE) to encode copper-free "click" ligation at a specific effector site in intact cells, enabling in situ formation of a covalent PROTAC-effector conjugate against a target protein of interest (POI). Modification at actionable effector sites drives degradation of the targeted protein, establishing the potential of these sites for TPD. Using SLIP, we systematically screened dozens of sites across E3 ligases and E2 enzymes from diverse classes, identifying multiple novel potentially PROTACable effector sites which are competent for TPD. SLIP adds a powerful approach to the proximity-induced pharmacology (PIP) toolbox, enabling future effector ligand discovery to fully enable TPD, and other emerging PIP modalities.
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Affiliation(s)
- Zhangping Xiao
- Department of Chemistry, Imperial College London, 82 Wood Lane, London W12 0BZ, UK
| | | | - Fangyuan Cao
- Department of Chemistry, Imperial College London, 82 Wood Lane, London W12 0BZ, UK
| | - Xinyue Zhang
- Department of Chemistry, Imperial College London, 82 Wood Lane, London W12 0BZ, UK
| | - Stan Xiaogang Li
- Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, NY 11794, United States
- Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, NY 11794, United States
| | - Sergei Kotelnikov
- Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, NY 11794, United States
- Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, NY 11794, United States
| | - Patrycja Michalska
- Department of Chemistry, Imperial College London, 82 Wood Lane, London W12 0BZ, UK
| | - Friederike Marte
- Department of Chemistry, Imperial College London, 82 Wood Lane, London W12 0BZ, UK
| | - Chloe Huang
- Department of Chemistry, Imperial College London, 82 Wood Lane, London W12 0BZ, UK
| | - Yudi Lu
- Department of Chemistry, Imperial College London, 82 Wood Lane, London W12 0BZ, UK
| | - Yunxuan Zhang
- Department of Chemistry, Imperial College London, 82 Wood Lane, London W12 0BZ, UK
| | - Erika Bernardini
- Department of Chemistry, Imperial College London, 82 Wood Lane, London W12 0BZ, UK
| | - Dima Kozakov
- Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, NY 11794, United States
- Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, NY 11794, United States
| | - Edward W. Tate
- Department of Chemistry, Imperial College London, 82 Wood Lane, London W12 0BZ, UK
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10
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Dyankova-Danovska T, Uzunova S, Danovski G, Stamatov R, Kanev PB, Atemin A, Ivanova A, Aleksandrov R, Stoynov S. In and out of Replication Stress: PCNA/RPA1-Based Dynamics of Fork Stalling and Restart in the Same Cell. Int J Mol Sci 2025; 26:667. [PMID: 39859385 PMCID: PMC11765805 DOI: 10.3390/ijms26020667] [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: 12/04/2024] [Revised: 01/08/2025] [Accepted: 01/12/2025] [Indexed: 01/27/2025] Open
Abstract
Replication forks encounter various impediments, which induce fork stalling and threaten genome stability, yet the precise dynamics of fork stalling and restart at the single-cell level remain elusive. Herein, we devise a live-cell microscopy-based approach to follow hydroxyurea-induced fork stalling and subsequent restart at 30 s resolution. We measure two distinct processes during fork stalling. One is rapid PCNA removal, which reflects the drop in DNA synthesis. The other is gradual RPA1 accumulation up to 2400 nt of ssDNA per fork despite an active intra-S checkpoint. Restoring the nucleotide pool enables a prompt restart without post-replicative ssDNA and a smooth cell cycle progression. ATR, but not ATM inhibition, accelerates hydroxyurea-induced RPA1 accumulation nine-fold, leading to RPA1 exhaustion within 20 min. Fork restart under ATR inhibition led to the persistence of ~600 nt ssDNA per fork after S-phase, which reached 2500 nt under ATR/ATM co-inhibition, with both scenarios leading to mitotic catastrophe. MRE11 inhibition had no effect on PCNA/RPA1 dynamics regardless of ATR activity. E3 ligase RAD18 was recruited at stalled replication forks in parallel to PCNA removal. Our results shed light on fork dynamics during nucleotide depletion and provide a valuable tool for interrogating the effects of replication stress-inducing anti-cancer agents.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Stoyno Stoynov
- Institute of Molecular Biology, Bulgarian Academy of Sciences, Acad. G. Bonchev Str. Bl. 21, 1113 Sofia, Bulgaria; (T.D.-D.); (S.U.); (G.D.); (R.S.); (P.-B.K.); (A.A.); (A.I.); (R.A.)
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11
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Zhang L, Deng Z, Du Y, Xu Z, Zhang T, Tong Z, Ai H, Liang LJ, Liu L. RAD18-catalysed formation of ubiquitination intermediate mimic of proliferating cell nuclear antigen PCNA. Bioorg Med Chem 2025; 117:118016. [PMID: 39580855 DOI: 10.1016/j.bmc.2024.118016] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2024] [Revised: 11/18/2024] [Accepted: 11/18/2024] [Indexed: 11/26/2024]
Abstract
The 2-((2-chloroethyl)amino)ethane-1-thiol (CAET)-based chemical trapping strategy is a practical tool for mechanistic studies of E3-catalysed ubiquitination. However, the construction of ubiquitination intermediate mimics (E2-Ub-substrate conjugates) via CAET has been limited to peptides, while its application to folded protein substrates remains unexplored. Here, we report that disulfide bond formation between E2-Ub (RAD6A-Ub) and the folded protein substrate PCNA (proliferating cell nuclear antigen) occurs upon the addition of the PCNA-associated E3 ligase RAD18. Leveraging this finding, we employed intein splicing technology to generate a stable, covalently linked RAD18-RAD6A-Ub-PCNA complex, enabling chemical crosslinking mass spectrometry (CX-MS) analysis to study the structure of this complex. This work showcases use of a substrate-associated E3 ligase to promote disulfide bond formation between an E2-Ub conjugate and a folded substrate for CAET-based trapping, thereby expanding the scope of this technique.
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Affiliation(s)
- Liying Zhang
- New Cornerstone Science Laboratory, Tsinghua-Peking Center for Life Sciences, Ministry of Education Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology, Center for Synthetic and Systems Biology, Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Zhiheng Deng
- New Cornerstone Science Laboratory, Tsinghua-Peking Center for Life Sciences, Ministry of Education Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology, Center for Synthetic and Systems Biology, Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Yunxiang Du
- New Cornerstone Science Laboratory, Tsinghua-Peking Center for Life Sciences, Ministry of Education Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology, Center for Synthetic and Systems Biology, Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Ziyu Xu
- New Cornerstone Science Laboratory, Tsinghua-Peking Center for Life Sciences, Ministry of Education Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology, Center for Synthetic and Systems Biology, Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Tianyi Zhang
- New Cornerstone Science Laboratory, Tsinghua-Peking Center for Life Sciences, Ministry of Education Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology, Center for Synthetic and Systems Biology, Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Zebin Tong
- New Cornerstone Science Laboratory, Tsinghua-Peking Center for Life Sciences, Ministry of Education Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology, Center for Synthetic and Systems Biology, Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Huasong Ai
- Institute of Translational Medicine, School of Pharmacy, School of Chemistry and Chemical Engineering, National Center for Translational Medicine (Shanghai), Shanghai Jiao Tong University, Shanghai 200240, China
| | - Lu-Jun Liang
- Center for BioAnalytical Chemistry, Hefei National Laboratory of Physical Science at Microscale, University of Science and Technology of China, Hefei 230026, China.
| | - Lei Liu
- New Cornerstone Science Laboratory, Tsinghua-Peking Center for Life Sciences, Ministry of Education Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology, Center for Synthetic and Systems Biology, Department of Chemistry, Tsinghua University, Beijing 100084, China.
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12
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Oldham KEA, Mabbitt PD. Ubiquitin E3 ligases in the plant Arg/N-degron pathway. Biochem J 2024; 481:1949-1965. [PMID: 39670824 DOI: 10.1042/bcj20240132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2024] [Revised: 11/24/2024] [Accepted: 11/26/2024] [Indexed: 12/14/2024]
Abstract
Regulation of protein longevity via the ubiquitin (Ub) - proteasome pathway is fundamental to eukaryotic biology. Ubiquitin E3 ligases (E3s) interact with substrate proteins and provide specificity to the pathway. A small subset of E3s bind to specific exposed N-termini (N-degrons) and promote the ubiquitination of the bound protein. Collectively these E3s, and other N-degron binding proteins, are known as N-recognins. There is considerable functional divergence between fungi, animal, and plant N-recognins. In plants, at least three proteins (PRT1, PRT6, and BIG) participate in the Arg/N-degron pathway. PRT1 has demonstrated E3 ligase activity, whereas PRT6 and BIG are candidate E3s. The Arg/N-degron pathway plays a central role in plant development, germination, and submersion tolerance. The pathway has been manipulated both to improve crop performance and for conditional protein degradation. A more detailed structural and biochemical understanding of the Arg/N-recognins and their substrates is required to fully realise the biotechnological potential of the pathway. This perspective focuses on the structural and molecular details of substrate recognition and ubiquitination in the plant Arg/N-degron pathway. While PRT1 appears to be plant specific, the PRT6 and BIG proteins are similar to UBR1 and UBR4, respectively. Analysis of the cryo-EM structures of Saccharomyces UBR1 suggests that the mode of ubiquitin conjugating enzyme (E2) and substrate recruitment is conserved in PRT6, but regulation of the two N-recognins may be significantly different. The structurally characterised domains from human UBR4 are also likely to be conserved in BIG, however, there are sizeable gaps in our understanding of both proteins.
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Affiliation(s)
- Keely E A Oldham
- Scion, Titokorangi Drive, Private Bag 3020, Rotorua 3046, New Zealand
| | - Peter D Mabbitt
- Scion, Titokorangi Drive, Private Bag 3020, Rotorua 3046, New Zealand
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13
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Yadav P, Tanweer S, Garg M, Verma M, Khan AS, Rahman SS, Ali A, Grover S, Kumar P, Kamthan M. Structural inscrutabilities of Histone (H2BK123) monoubiquitination: A systematic review. Int J Biol Macromol 2024; 280:135977. [PMID: 39322127 DOI: 10.1016/j.ijbiomac.2024.135977] [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: 06/19/2024] [Revised: 09/11/2024] [Accepted: 09/22/2024] [Indexed: 09/27/2024]
Abstract
Histone H2B monoubiquitination in budding yeast is a highly conserved post-translational modification. It is involved in normal functions of the cells like DNA Repair, RNA Pol II activation, trans-histone H3K and H79K methylation, meiosis, vesicle budding, etc. Deregulation of H2BK123ub can lead to the activation of proto-oncogenes and is also linked to neurodegenerative and heart diseases. Recent discoveries have enhanced the mechanistic underpinnings of H2BK123ub. For the first time, the Rad6's acidic tail has been implicated in histone recognition and interaction with Bre1's RBD domain. The non-canonical backside of Rad6 showed inhibition in polyubiquitination activity. Bre1 domains RBD and RING play a role in site-specific ubiquitination. The role of single Alaline residue in Rad6 activity. Understanding the mechanism of ubiquitination before moving to therapeutic applications is important. Current advancements in this field indicate the creation of novel therapeutic approaches and a foundation for further study.
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Affiliation(s)
- Pawan Yadav
- Department of Biochemistry, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi 110062, India
| | - Sana Tanweer
- Department of Molecular Medicine, School of Interdisciplinary Sciences and Technology, Jamia Hamdard, New Delhi 110062, India
| | - Manika Garg
- Department of Biochemistry, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi 110062, India
| | - Muskan Verma
- Department of Biochemistry, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi 110062, India
| | - Aiysha Siddiq Khan
- Department of Biochemistry, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi 110062, India
| | - Saman Saim Rahman
- Department of Biochemistry, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi 110062, India
| | - Asghar Ali
- Department of Biochemistry, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi 110062, India
| | - Sonam Grover
- Department of Molecular Medicine, School of Interdisciplinary Sciences and Technology, Jamia Hamdard, New Delhi 110062, India
| | - Pankaj Kumar
- Department of Biochemistry, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi 110062, India.
| | - Mohan Kamthan
- Department of Biochemistry, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi 110062, India.
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14
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Ryu E, Yoo J, Kang MS, Ha NY, Jang Y, Kim J, Kim Y, Kim BG, Kim S, Myung K, Kang S. ATAD5 functions as a regulatory platform for Ub-PCNA deubiquitination. Proc Natl Acad Sci U S A 2024; 121:e2315759121. [PMID: 39145935 PMCID: PMC11348035 DOI: 10.1073/pnas.2315759121] [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: 09/12/2023] [Accepted: 07/11/2024] [Indexed: 08/16/2024] Open
Abstract
Ubiquitination status of proliferating cell nuclear antigen (PCNA) is crucial for regulating DNA lesion bypass. After the resolution of fork stalling, PCNA is subsequently deubiquitinated, but the underlying mechanism remains undefined. We found that the N-terminal domain of ATAD5 (ATAD5-N), the largest subunit of the PCNA-unloading complex, functions as a scaffold for Ub-PCNA deubiquitination. ATAD5 recognizes DNA-loaded Ub-PCNA through distinct DNA-binding and PCNA-binding motifs. Furthermore, ATAD5 forms a heterotrimeric complex with UAF1-USP1 deubiquitinase, facilitating the deubiquitination of DNA-loaded Ub-PCNA. ATAD5 also enhances the Ub-PCNA deubiquitination by USP7 and USP11 through specific interactions. ATAD5 promotes the distinct deubiquitination process of UAF1-USP1, USP7, and USP11 for poly-Ub-PCNA. Additionally, ATAD5 mutants deficient in UAF1-binding had increased sensitivity to DNA-damaging agents. Our results ultimately reveal that ATAD5 and USPs cooperate to efficiently deubiquitinate Ub-PCNA prior to its release from the DNA in order to safely deactivate the DNA repair process.
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Affiliation(s)
- Eunjin Ryu
- Center for Genomic Integrity, Institute for Basic Science, Ulsan44919, Republic of Korea
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan44919, Republic of Korea
| | - Juyeong Yoo
- Center for Genomic Integrity, Institute for Basic Science, Ulsan44919, Republic of Korea
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan44919, Republic of Korea
| | - Mi-Sun Kang
- Center for Genomic Integrity, Institute for Basic Science, Ulsan44919, Republic of Korea
| | - Na Young Ha
- Center for Genomic Integrity, Institute for Basic Science, Ulsan44919, Republic of Korea
| | - Yewon Jang
- Center for Genomic Integrity, Institute for Basic Science, Ulsan44919, Republic of Korea
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan44919, Republic of Korea
| | - Jinwoo Kim
- Center for Genomic Integrity, Institute for Basic Science, Ulsan44919, Republic of Korea
| | - Yeongjae Kim
- Center for Genomic Integrity, Institute for Basic Science, Ulsan44919, Republic of Korea
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan44919, Republic of Korea
| | - Byung-Gyu Kim
- Center for Genomic Integrity, Institute for Basic Science, Ulsan44919, Republic of Korea
| | - Shinseog Kim
- Center for Genomic Integrity, Institute for Basic Science, Ulsan44919, Republic of Korea
| | - Kyungjae Myung
- Center for Genomic Integrity, Institute for Basic Science, Ulsan44919, Republic of Korea
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan44919, Republic of Korea
| | - Sukhyun Kang
- Center for Genomic Integrity, Institute for Basic Science, Ulsan44919, Republic of Korea
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15
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Foster BM, Wang Z, Schmidt CK. DoUBLing up: ubiquitin and ubiquitin-like proteases in genome stability. Biochem J 2024; 481:515-545. [PMID: 38572758 PMCID: PMC11088880 DOI: 10.1042/bcj20230284] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 03/05/2024] [Accepted: 03/18/2024] [Indexed: 04/05/2024]
Abstract
Maintaining stability of the genome requires dedicated DNA repair and signalling processes that are essential for the faithful duplication and propagation of chromosomes. These DNA damage response (DDR) mechanisms counteract the potentially mutagenic impact of daily genotoxic stresses from both exogenous and endogenous sources. Inherent to these DNA repair pathways is the activity of protein factors that instigate repair processes in response to DNA lesions. The regulation, coordination, and orchestration of these DDR factors is carried out, in a large part, by post-translational modifications, such as phosphorylation, ubiquitylation, and modification with ubiquitin-like proteins (UBLs). The importance of ubiquitylation and UBLylation with SUMO in DNA repair is well established, with the modified targets and downstream signalling consequences relatively well characterised. However, the role of dedicated erasers for ubiquitin and UBLs, known as deubiquitylases (DUBs) and ubiquitin-like proteases (ULPs) respectively, in genome stability is less well established, particularly for emerging UBLs such as ISG15 and UFM1. In this review, we provide an overview of the known regulatory roles and mechanisms of DUBs and ULPs involved in genome stability pathways. Expanding our understanding of the molecular agents and mechanisms underlying the removal of ubiquitin and UBL modifications will be fundamental for progressing our knowledge of the DDR and likely provide new therapeutic avenues for relevant human diseases, such as cancer.
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Affiliation(s)
- Benjamin M. Foster
- Manchester Cancer Research Centre (MCRC), Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, 555 Wilmslow Road, Manchester M20 4GJ, U.K
| | - Zijuan Wang
- Manchester Cancer Research Centre (MCRC), Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, 555 Wilmslow Road, Manchester M20 4GJ, U.K
| | - Christine K. Schmidt
- Manchester Cancer Research Centre (MCRC), Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, 555 Wilmslow Road, Manchester M20 4GJ, U.K
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16
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Poirson J, Cho H, Dhillon A, Haider S, Imrit AZ, Lam MHY, Alerasool N, Lacoste J, Mizan L, Wong C, Gingras AC, Schramek D, Taipale M. Proteome-scale discovery of protein degradation and stabilization effectors. Nature 2024; 628:878-886. [PMID: 38509365 DOI: 10.1038/s41586-024-07224-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 02/22/2024] [Indexed: 03/22/2024]
Abstract
Targeted protein degradation and stabilization are promising therapeutic modalities because of their potency, versatility and their potential to expand the druggable target space1,2. However, only a few of the hundreds of E3 ligases and deubiquitinases in the human proteome have been harnessed for this purpose, which substantially limits the potential of the approach. Moreover, there may be other protein classes that could be exploited for protein stabilization or degradation3-5, but there are currently no methods that can identify such effector proteins in a scalable and unbiased manner. Here we established a synthetic proteome-scale platform to functionally identify human proteins that can promote the degradation or stabilization of a target protein in a proximity-dependent manner. Our results reveal that the human proteome contains a large cache of effectors of protein stability. The approach further enabled us to comprehensively compare the activities of human E3 ligases and deubiquitinases, identify and characterize non-canonical protein degraders and stabilizers and establish that effectors have vastly different activities against diverse targets. Notably, the top degraders were more potent against multiple therapeutically relevant targets than the currently used E3 ligases cereblon and VHL. Our study provides a functional catalogue of stability effectors for targeted protein degradation and stabilization and highlights the potential of induced proximity screens for the discovery of new proximity-dependent protein modulators.
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Affiliation(s)
- Juline Poirson
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada
| | - Hanna Cho
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada
| | - Akashdeep Dhillon
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Shahan Haider
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Ahmad Zoheyr Imrit
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Mandy Hiu Yi Lam
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada
| | - Nader Alerasool
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Jessica Lacoste
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Lamisa Mizan
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Cassandra Wong
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Anne-Claude Gingras
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Daniel Schramek
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Mikko Taipale
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada.
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada.
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17
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Griffith-Jones S, Álvarez L, Mukhopadhyay U, Gharbi S, Rettel M, Adams M, Hennig J, Bhogaraju S. Structural basis for RAD18 regulation by MAGEA4 and its implications for RING ubiquitin ligase binding by MAGE family proteins. EMBO J 2024; 43:1273-1300. [PMID: 38448672 PMCID: PMC10987633 DOI: 10.1038/s44318-024-00058-9] [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: 07/17/2023] [Revised: 02/06/2024] [Accepted: 02/07/2024] [Indexed: 03/08/2024] Open
Abstract
MAGEA4 is a cancer-testis antigen primarily expressed in the testes but aberrantly overexpressed in several cancers. MAGEA4 interacts with the RING ubiquitin ligase RAD18 and activates trans-lesion DNA synthesis (TLS), potentially favouring tumour evolution. Here, we employed NMR and AlphaFold2 (AF) to elucidate the interaction mode between RAD18 and MAGEA4, and reveal that the RAD6-binding domain (R6BD) of RAD18 occupies a groove in the C-terminal winged-helix subdomain of MAGEA4. We found that MAGEA4 partially displaces RAD6 from the RAD18 R6BD and inhibits degradative RAD18 autoubiquitination, which could be countered by a competing peptide of the RAD18 R6BD. AlphaFold2 and cross-linking mass spectrometry (XL-MS) also revealed an evolutionary invariant intramolecular interaction between the catalytic RING and the DNA-binding SAP domains of RAD18, which is essential for PCNA mono-ubiquitination. Using interaction proteomics, we found that another Type-I MAGE, MAGE-C2, interacts with the RING ubiquitin ligase TRIM28 in a manner similar to the MAGEA4/RAD18 complex, suggesting that the MAGEA4 peptide-binding groove also serves as a ligase-binding cleft in other type-I MAGEs. Our data provide new insights into the mechanism and regulation of RAD18-mediated PCNA mono-ubiquitination.
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Affiliation(s)
| | - Lucía Álvarez
- European Molecular Biology Laboratory, Meyerhofstraße 1, 69117, Heidelberg, Germany
| | - Urbi Mukhopadhyay
- European Molecular Biology Laboratory, 71 Avenue des Martyrs, 38042, Grenoble, France
| | - Sarah Gharbi
- European Molecular Biology Laboratory, 71 Avenue des Martyrs, 38042, Grenoble, France
| | - Mandy Rettel
- European Molecular Biology Laboratory, Meyerhofstraße 1, 69117, Heidelberg, Germany
| | - Michael Adams
- European Molecular Biology Laboratory, 71 Avenue des Martyrs, 38042, Grenoble, France
| | - Janosch Hennig
- European Molecular Biology Laboratory, Meyerhofstraße 1, 69117, Heidelberg, Germany
- Biochemistry IV, Biophysical Chemistry, University of Bayreuth, Universitätsstrasse 30, 95447, Bayreuth, Germany
| | - Sagar Bhogaraju
- European Molecular Biology Laboratory, 71 Avenue des Martyrs, 38042, Grenoble, France.
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18
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Chen S, Pan C, Huang J, Liu T. ATR limits Rad18-mediated PCNA monoubiquitination to preserve replication fork and telomerase-independent telomere stability. EMBO J 2024; 43:1301-1324. [PMID: 38467834 PMCID: PMC10987609 DOI: 10.1038/s44318-024-00066-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 02/15/2024] [Accepted: 02/26/2024] [Indexed: 03/13/2024] Open
Abstract
Upon replication fork stalling, the RPA-coated single-stranded DNA (ssDNA) formed behind the fork activates the ataxia telangiectasia-mutated and Rad3-related (ATR) kinase, concomitantly initiating Rad18-dependent monoubiquitination of PCNA. However, whether crosstalk exists between these two events and the underlying physiological implications of this interplay remain elusive. In this study, we demonstrate that during replication stress, ATR phosphorylates human Rad18 at Ser403, an adjacent residue to a previously unidentified PIP motif (PCNA-interacting peptide) within Rad18. This phosphorylation event disrupts the interaction between Rad18 and PCNA, thereby restricting the extent of Rad18-mediated PCNA monoubiquitination. Consequently, excessive accumulation of the tumor suppressor protein SLX4, now characterized as a novel reader of ubiquitinated PCNA, at stalled forks is prevented, contributing to the prevention of stalled fork collapse. We further establish that ATR preserves telomere stability in alternative lengthening of telomere (ALT) cells by restricting Rad18-mediated PCNA monoubiquitination and excessive SLX4 accumulation at telomeres. These findings shed light on the complex interplay between ATR activation, Rad18-dependent PCNA monoubiquitination, and SLX4-associated stalled fork processing, emphasizing the critical role of ATR in preserving replication fork stability and facilitating telomerase-independent telomere maintenance.
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Affiliation(s)
- Siyuan Chen
- Zhejiang Provincial Key Laboratory of Geriatrics and Geriatrics Institute of Zhejiang Province, Affiliated Zhejiang Hospital, Zhejiang University School of Medicine, 310058, Hangzhou, China
- The MOE Key Laboratory of Biosystems Homeostasis & Protection and Zhejiang Provincial Key Laboratory of Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, 310058, Hangzhou, China
| | - Chen Pan
- The MOE Key Laboratory of Biosystems Homeostasis & Protection and Zhejiang Provincial Key Laboratory of Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, 310058, Hangzhou, China
| | - Jun Huang
- Zhejiang Provincial Key Laboratory of Geriatrics and Geriatrics Institute of Zhejiang Province, Affiliated Zhejiang Hospital, Zhejiang University School of Medicine, 310058, Hangzhou, China.
- The MOE Key Laboratory of Biosystems Homeostasis & Protection and Zhejiang Provincial Key Laboratory of Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, 310058, Hangzhou, China.
- Center for Life Sciences, Shaoxing Institute, Zhejiang University, 321000, Shaoxing, China.
| | - Ting Liu
- Zhejiang Provincial Key Laboratory of Geriatrics and Geriatrics Institute of Zhejiang Province, Affiliated Zhejiang Hospital, Zhejiang University School of Medicine, 310058, Hangzhou, China.
- Department of Cell Biology, and Department of General Surgery of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, 310058, Hangzhou, China.
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19
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Barnsby-Greer L, Mabbitt PD, Dery MA, Squair DR, Wood NT, Lamoliatte F, Lange SM, Virdee S. UBE2A and UBE2B are recruited by an atypical E3 ligase module in UBR4. Nat Struct Mol Biol 2024; 31:351-363. [PMID: 38182926 PMCID: PMC10873205 DOI: 10.1038/s41594-023-01192-4] [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: 02/15/2023] [Accepted: 11/27/2023] [Indexed: 01/07/2024]
Abstract
UBR4 is a 574 kDa E3 ligase (E3) of the N-degron pathway with roles in neurodevelopment, age-associated muscular atrophy and cancer. The catalytic module that carries out ubiquitin (Ub) transfer remains unknown. Here we identify and characterize a distinct E3 module within human UBR4 consisting of a 'hemiRING' zinc finger, a helical-rich UBR zinc-finger interacting (UZI) subdomain, and an N-terminal region that can serve as an affinity factor for the E2 conjugating enzyme (E2). The structure of an E2-E3 complex provides atomic-level insight into the specificity determinants of the hemiRING toward the cognate E2s UBE2A/UBE2B. Via an allosteric mechanism, the UZI subdomain modestly activates the Ub-loaded E2 (E2∼Ub). We propose attenuated activation is complemented by the intrinsically high lysine reactivity of UBE2A, and their cooperation imparts a reactivity profile important for substrate specificity and optimal degradation kinetics. These findings reveal the mechanistic underpinnings of a neuronal N-degron E3, its specific recruitment of UBE2A, and highlight the underappreciated architectural diversity of cross-brace domains with Ub E3 activity.
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Affiliation(s)
- Lucy Barnsby-Greer
- MRC Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Scotland, UK
| | - Peter D Mabbitt
- MRC Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Scotland, UK
- Scion, Rotorua, New Zealand
| | - Marc-Andre Dery
- MRC Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Scotland, UK
| | - Daniel R Squair
- MRC Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Scotland, UK
| | - Nicola T Wood
- MRC Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Scotland, UK
| | - Frederic Lamoliatte
- MRC Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Scotland, UK
| | - Sven M Lange
- MRC Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Scotland, UK
| | - Satpal Virdee
- MRC Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Scotland, UK.
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20
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Yadav P, Gupta M, Wazahat R, Islam Z, Tsutakawa SE, Kamthan M, Kumar P. Structural basis for the role of C-terminus acidic tail of Saccharomyces cerevisiae ubiquitin-conjugating enzyme (Rad6) in E3 ligase (Bre1) mediated recognition of histones. Int J Biol Macromol 2024; 254:127717. [PMID: 37923031 DOI: 10.1016/j.ijbiomac.2023.127717] [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: 08/15/2023] [Revised: 10/07/2023] [Accepted: 10/25/2023] [Indexed: 11/07/2023]
Abstract
Ubiquitination of histone H2B on chromatin is key to gene regulation. E3 ligase Bre1 and E2 Rad6 in Saccharomyces cerevisiae associate together to catalyze mono-ubiquitination at histone H2BK123. Prior studies identified the role of a highly dynamic C-terminal acidic tail of Rad6 indispensable for H2BK123 mono-ubiquitination. However, the mechanistic basis for the Rad6-acidic tail role remained elusive. Using different structural and biophysical approaches, this study for the first time uncovers the direct role of Rad6-acidic tail in interaction with the Bre1 Rad6-Binding Domain (RBD) and recognition of histones surface to facilitate histone H2B mono-ubiquitination. A combination of NMR, SAXS, ITC, site-directed mutagenesis and molecular dynamics studies reveal that RBD domain of Bre1 interacts with Rad6 to stabilize the dynamics of acidic tail. This Bre1-RBD mediated stability in acidic tail of Rad6 could be one of the key factors for facilitating correct recognition of histone surface and ubiquitin-transfer at H2BK123. We provide biophysical evidence that Rad6-acidic tail and a positivity charged surface on histone H2B are involved in recognition of E2:Histones. Taken together, this study uncovers the mechanistic basis for the role of Rad6-acidic in Bre1-RBD mediated recognition of histone surface that ensure the histone H2B mono-ubiquitination.
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Affiliation(s)
- Pawan Yadav
- Department of Biochemistry, School of Chemical and Life Sciences, Jamia Hamdard University, New Delhi 110062, India
| | - Manish Gupta
- Department of Medicine, Johns Hopkins University, Baltimore, MD 21231, USA
| | - Rushna Wazahat
- Department of Biochemistry, School of Chemical and Life Sciences, Jamia Hamdard University, New Delhi 110062, India
| | - Zeyaul Islam
- Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation, Doha, Qatar
| | - Susan E Tsutakawa
- Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Mohan Kamthan
- Department of Biochemistry, School of Chemical and Life Sciences, Jamia Hamdard University, New Delhi 110062, India
| | - Pankaj Kumar
- Department of Biochemistry, School of Chemical and Life Sciences, Jamia Hamdard University, New Delhi 110062, India.
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21
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Middleton AJ, Barzak FM, Fokkens TJ, Nguyen K, Day CL. Zinc finger 1 of the RING E3 ligase, RNF125, interacts with the E2 to enhance ubiquitylation. Structure 2023; 31:1208-1219.e5. [PMID: 37541247 DOI: 10.1016/j.str.2023.07.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2023] [Revised: 06/08/2023] [Accepted: 07/12/2023] [Indexed: 08/06/2023]
Abstract
Inflammation is essential for healthy immune function, wound healing, and resolution of infection. RIG-I is a key RNA sensor that initiates an immune response, with activation and termination of RIG-I signaling reliant on its modification with ubiquitin. The RING E3 ubiquitin ligase, RNF125, has a critical role in the attenuation of RIG-I signaling, yet it is not known how RNF125 promotes ubiquitin transfer or how its activity is regulated. Here we show that the E3 ligase activity of RNF125 relies on the first zinc finger (ZF1) as well as the RING domain. Surprisingly, ZF1 helps recruit the E2, while residues N-terminal to the RING domain appear to activate the E2∼Ub conjugate. These discoveries help explain how RNF125 brings about the termination of RIG-I dependent inflammatory responses, and help account for the contribution of RNF125 to disease. This study also reveals a new role for ZF domains in E3 ligases.
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Affiliation(s)
- Adam J Middleton
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin 9054, New Zealand
| | - Fareeda M Barzak
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin 9054, New Zealand
| | - Thornton J Fokkens
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin 9054, New Zealand
| | - Khanh Nguyen
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin 9054, New Zealand
| | - Catherine L Day
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin 9054, New Zealand.
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22
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Shukla PK, Bissell JE, Kumar S, Pokhrel S, Palani S, Radmall K, Obidi O, Parnell TJ, Brasch J, Shrieve D, Chandrasekharan M. Structure and functional determinants of Rad6-Bre1 subunits in the histone H2B ubiquitin-conjugating complex. Nucleic Acids Res 2023; 51:2117-2136. [PMID: 36715322 PMCID: PMC10018343 DOI: 10.1093/nar/gkad012] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 12/28/2022] [Accepted: 01/04/2023] [Indexed: 01/31/2023] Open
Abstract
The conserved complex of the Rad6 E2 ubiquitin-conjugating enzyme and the Bre1 E3 ubiquitin ligase catalyzes histone H2B monoubiquitination (H2Bub1), which regulates chromatin dynamics during transcription and other nuclear processes. Here, we report a crystal structure of Rad6 and the non-RING domain N-terminal region of Bre1, which shows an asymmetric homodimer of Bre1 contacting a conserved loop on the Rad6 'backside'. This contact is distant from the Rad6 catalytic site and is the location of mutations that impair telomeric silencing in yeast. Mutational analyses validated the importance of this contact for the Rad6-Bre1 interaction, chromatin-binding dynamics, H2Bub1 formation and gene expression. Moreover, the non-RING N-terminal region of Bre1 is sufficient to confer nucleosome binding ability to Rad6 in vitro. Interestingly, Rad6 P43L protein, an interaction interface mutant and equivalent to a cancer mutation in the human homolog, bound Bre1 5-fold more tightly than native Rad6 in vitro, but showed reduced chromatin association of Bre1 and reduced levels of H2Bub1 in vivo. These surprising observations imply conformational transitions of the Rad6-Bre1 complex during its chromatin-associated functional cycle, and reveal the differential effects of specific disease-relevant mutations on the chromatin-bound and unbound states. Overall, our study provides structural insights into Rad6-Bre1 interaction through a novel interface that is important for their biochemical and biological responses.
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Affiliation(s)
- Prakash K Shukla
- Department of Radiation Oncology, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
- Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Jesse E Bissell
- Department of Radiation Oncology, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
- Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Sanjit Kumar
- Centre for Bioseparation Technology, Vellore Institute of Technology, Vellore, Tamil Nadu 632014, India
| | - Srijana Pokhrel
- Department of Radiation Oncology, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
- Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Sowmiya Palani
- Department of Radiation Oncology, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
- Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Kaitlin S Radmall
- Department of Radiation Oncology, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
- Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Onyeka Obidi
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Timothy J Parnell
- Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Julia Brasch
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Dennis C Shrieve
- Department of Radiation Oncology, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Mahesh B Chandrasekharan
- Department of Radiation Oncology, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
- Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
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23
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Shi M, Zhao J, Zhang S, Huang W, Li M, Bai X, Zhang W, Zhang K, Chen X, Xiang S. Structural basis for the Rad6 activation by the Bre1 N-terminal domain. eLife 2023; 12:84157. [PMID: 36912886 PMCID: PMC10036116 DOI: 10.7554/elife.84157] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 03/10/2023] [Indexed: 03/14/2023] Open
Abstract
The mono-ubiquitination of the histone protein H2B (H2Bub1) is a highly conserved histone post-translational modification that plays critical roles in many fundamental processes. In yeast, this modification is catalyzed by the conserved Bre1-Rad6 complex. Bre1 contains a unique N-terminal Rad6-binding domain (RBD), how it interacts with Rad6 and contributes to the H2Bub1 catalysis is unclear. Here, we present crystal structure of the Bre1 RBD-Rad6 complex and structure-guided functional studies. Our structure provides a detailed picture of the interaction between the dimeric Bre1 RBD and a single Rad6 molecule. We further found that the interaction stimulates Rad6's enzymatic activity by allosterically increasing its active site accessibility and likely contribute to the H2Bub1 catalysis through additional mechanisms. In line with these important functions, we found that the interaction is crucial for multiple H2Bub1-regulated processes. Our study provides molecular insights into the H2Bub1 catalysis.
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Affiliation(s)
- Meng Shi
- Department of Biochemistry and Molecular Biology, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), The province and ministry co-sponsored collaborative innovation center for medical epigenetics, Tianjin Medical University, Tianjin, China
| | - Jiaqi Zhao
- Department of Biochemistry and Molecular Biology, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), The province and ministry co-sponsored collaborative innovation center for medical epigenetics, Tianjin Medical University, Tianjin, China
| | - Simin Zhang
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, TaiKang Center for Life and Medical Sciences, Frontier Science Centre of Immunology and Metabolism, The Institute of Advanced Studies, Wuhan University, Wuhan, China
| | - Wei Huang
- Department of Biochemistry and Molecular Biology, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), The province and ministry co-sponsored collaborative innovation center for medical epigenetics, Tianjin Medical University, Tianjin, China
| | - Mengfei Li
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, TaiKang Center for Life and Medical Sciences, Frontier Science Centre of Immunology and Metabolism, The Institute of Advanced Studies, Wuhan University, Wuhan, China
| | - Xue Bai
- Department of Biochemistry and Molecular Biology, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), The province and ministry co-sponsored collaborative innovation center for medical epigenetics, Tianjin Medical University, Tianjin, China
| | - Wenxue Zhang
- Department of Radiation Oncology, Tianjin Medical University General Hospital, Tianjin, China
| | - Kai Zhang
- Department of Biochemistry and Molecular Biology, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), The province and ministry co-sponsored collaborative innovation center for medical epigenetics, Tianjin Medical University, Tianjin, China
| | - Xuefeng Chen
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, TaiKang Center for Life and Medical Sciences, Frontier Science Centre of Immunology and Metabolism, The Institute of Advanced Studies, Wuhan University, Wuhan, China
| | - Song Xiang
- Department of Biochemistry and Molecular Biology, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), The province and ministry co-sponsored collaborative innovation center for medical epigenetics, Tianjin Medical University, Tianjin, China
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24
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Shukla PK, Sinha D, Leng AM, Bissell JE, Thatipamula S, Ganguly R, Radmall KS, Skalicky JJ, Shrieve DC, Chandrasekharan MB. Mutations of Rad6 E2 ubiquitin-conjugating enzymes at alanine-126 affect ubiquitination activity and decrease enzyme stability. J Biol Chem 2022; 298:102524. [PMID: 36162503 PMCID: PMC9630792 DOI: 10.1016/j.jbc.2022.102524] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Revised: 09/16/2022] [Accepted: 09/17/2022] [Indexed: 11/28/2022] Open
Abstract
Rad6, an E2 ubiquitin-conjugating enzyme conserved from yeast to humans, functions in transcription, genome maintenance, and proteostasis. The contributions of many conserved secondary structures of Rad6 and its human homologs UBE2A and UBE2B to their biological functions are not understood. A mutant RAD6 allele with a missense substitution at alanine-126 (A126) of helix-3 that causes defects in telomeric gene silencing, DNA repair, and protein degradation was reported over 2 decades ago. Here, using a combination of genetics, biochemical, biophysical, and computational approaches, we discovered that helix-3 A126 mutations compromise the ability of Rad6 to ubiquitinate target proteins without disrupting interactions with partner E3 ubiquitin-ligases that are required for their various biological functions in vivo. Explaining the defective in vitro or in vivo ubiquitination activities, molecular dynamics simulations and NMR showed that helix-3 A126 mutations cause local disorder of the catalytic pocket of Rad6 in addition to disorganizing the global structure of the protein to decrease its stability in vivo. We also show that helix-3 A126 mutations deform the structures of UBE2A and UBE2B, the human Rad6 homologs, and compromise the in vitro ubiquitination activity and folding of UBE2B. Providing insights into their ubiquitination defects, we determined helix-3 A126 mutations impair the initial ubiquitin charging and the final discharging steps during substrate ubiquitination by Rad6. In summary, our studies reveal that the conserved helix-3 is a crucial structural constituent that controls the organization of catalytic pockets, enzymatic activities, and biological functions of the Rad6-family E2 ubiquitin-conjugating enzymes.
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Affiliation(s)
- Prakash K Shukla
- Department of Radiation Oncology and Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Dhiraj Sinha
- IHU, Aix Marseille University, Marseille, France
| | - Andrew M Leng
- Department of Radiation Oncology and Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Jesse E Bissell
- Department of Radiation Oncology and Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Shravya Thatipamula
- Department of Radiation Oncology and Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Rajarshi Ganguly
- Department of Radiation Oncology and Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Kaitlin S Radmall
- Department of Radiation Oncology and Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Jack J Skalicky
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Dennis C Shrieve
- Department of Radiation Oncology and Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Mahesh B Chandrasekharan
- Department of Radiation Oncology and Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, UT 84112, USA.
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25
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Birkou M, Delegkou GN, Marousis KD, Fragkaki N, Toro T, Episkopou V, Spyroulias GA. Unveiling the Essential Role of Arkadia's Non-RING Elements in the Ubiquitination Process. Int J Mol Sci 2022; 23:10585. [PMID: 36142504 PMCID: PMC9501438 DOI: 10.3390/ijms231810585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 09/01/2022] [Accepted: 09/08/2022] [Indexed: 11/29/2022] Open
Abstract
Arkadia is a positive regulator of the TGFβ-SMAD2/3 pathway, acting through its C-terminal RING-H2 domain and targeting for degradation of its negative regulators. Here we explore the role of regions outside the RING domain (non-RING elements) of Arkadia on the E2-E3 interaction. The contribution of the non-RING elements was addressed using Arkadia RING 68 aa and Arkadia 119 aa polypeptides. The highly conserved NRGA (asparagine-arginine-glycine-alanine) and TIER (threonine-isoleucine-glutamine-arginine) motifs within the 119 aa Arkadia polypeptide, have been shown to be required for pSMAD2/3 substrate recognition and ubiquitination in vivo. However, the role of the NRGA and TIER motifs in the enzymatic activity of Arkadia has not been addressed. Here, nuclear magnetic resonance interaction studies with the E2 enzyme, UBCH5B, C85S UBCH5B-Ub oxyester hydrolysis, and auto-ubiquitination assays were used to address the role of the non-RING elements in E2-E3 interaction and in the enzymatic activity of the RING. The results support that the non-RING elements including the NRGA and TIER motifs are required for E2-E3 recognition and interaction and for efficient auto-ubiquitination. Furthermore, while Arkadia isoform-2 and its close homologue Arkadia 2C are known to interact with free ubiquitin, the results here showed that Arkadia isoform-1 does not interact with free ubiquitin.
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Affiliation(s)
- Maria Birkou
- Department of Pharmacy, University of Patras, 26504 Patras, Greece
| | | | | | - Nefeli Fragkaki
- Department of Pharmacy, University of Patras, 26504 Patras, Greece
| | - Tamara Toro
- Department of Pharmacy, University of Patras, 26504 Patras, Greece
| | - Vasso Episkopou
- Department of Brain Sciences, Imperial College, London W12 0NN, UK
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26
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Fenteany G, Sharma G, Gaur P, Borics A, Wéber E, Kiss E, Haracska L. A series of xanthenes inhibiting Rad6 function and Rad6-Rad18 interaction in the PCNA ubiquitination cascade. iScience 2022; 25:104053. [PMID: 35355521 PMCID: PMC8958325 DOI: 10.1016/j.isci.2022.104053] [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: 06/15/2021] [Revised: 12/13/2021] [Accepted: 03/08/2022] [Indexed: 11/24/2022] Open
Abstract
Ubiquitination of proliferating cell nuclear antigen (PCNA) triggers pathways of DNA damage tolerance, including mutagenic translesion DNA synthesis, and comprises a cascade of reactions involving the E1 ubiquitin-activating enzyme Uba1, the E2 ubiquitin-conjugating enzyme Rad6, and the E3 ubiquitin ligase Rad18. We report here the discovery of a series of xanthenes that inhibit PCNA ubiquitination, Rad6∼ubiquitin thioester formation, and the Rad6–Rad18 interaction. Structure-activity relationship experiments across multiple assays reveal chemical and structural features important for different activities along the pathway to PCNA ubiquitination. The compounds that inhibit these processes are all a subset of the xanthen-3-ones we tested. These small molecules thus represent first-in-class probes of Rad6 function and the association of Rad6 and Rad18, the latter being a new inhibitory activity discovered for a small molecule, in the PCNA ubiquitination cascade and potential therapeutic agents to contain cancer progression. Alpha-based HTS for PCNA ubiquitination modulators Target-based characterization of hits A series of xanthenes that inhibit Rad6 functions and Rad6–Rad18 interaction
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27
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Zeng X, Zheng W, Sheng Y, Ma H. UBE2B promotes ovarian cancer growth via promoting RAD18 mediated ZMYM2 monoubiquitination and stabilization. Bioengineered 2022; 13:8000-8012. [PMID: 35313791 PMCID: PMC9161992 DOI: 10.1080/21655979.2022.2048991] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Ubiquitin-conjugating enzyme E2 B (UBE2B) can form a heterodimer with ubiquitin E3 ligase RAD18. In this study, we aimed to explore new substrates of the UBE2B/RAD18 complex and their regulatory effects in ovarian cancer. Protein physical interactions were predicted using GeneMANIA. Serial sections of commercial ovarian cancer tissue arrays were used to check the protein expression of UBE2B, RAD18, and ZMYM2. Immunofluorescence staining and co-immunoprecipitation assays were performed to check their location and interactions. Cycloheximide chase assay was applied to explore the influence of UBE2B and RAD18 on ZMYM2 degradation. Xenograft tumor models were constructed to assess the influence of the UBE2B-ZMYM2 axis on in vivo tumor growth. A strong positive correlation between UBE2B and ZMYM2 and a moderate positive correlation between RAD18 and ZMYM2 were observed in 23 ovarian cancer cases. In CAOV4 and OVCAR3 cells, myc-ZMYM2 interacted with UBE2B and RAD18. UBE2B and ZMYM2 could be detected in the samples immunoprecipitated by anti-RAD18. UBE2B overexpression or knockdown did not alter ZMYM2 mRNA expression. UBE2B overexpression increased ZMYM2 monoubiquitination but reduced its polyubiquitination. RAD18 knockdown impaired UBE2B-induced ZMYM2 monoubiquitination. UBE2B overexpression significantly enhanced the stability of ZMYM2 protein, the effect of which was weakened by RAD18 knockdown. UBE2B overexpression significantly enhanced the growth of xenograft tumors derived from CAOV4 cells. ZMYM2 knockdown remarkedly suppressed tumor growth and impaired the growth-promoting effect of UBE2B overexpression. In conclusion, this study revealed a novel regulatory effect of the UBE2B/RAD18 complex on ZMYM2 monoubiquitination and stability in ovarian cancer.
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Affiliation(s)
- Xi Zeng
- Department of Obstetrics & Gynecology, Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Wen Zheng
- Laboratory of Clinical Proteomics and Metabolomics, Institutes for Systems Genetics, Frontiers Science Center for Disease-related Molecular Network, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Yuting Sheng
- Department of Obstetrics & Gynecology, Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Hongwei Ma
- Department of Obstetrics & Gynecology, Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China
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28
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Varejão N, Lascorz J, Codina-Fabra J, Bellí G, Borràs-Gas H, Torres-Rosell J, Reverter D. Structural basis for the E3 ligase activity enhancement of yeast Nse2 by SUMO-interacting motifs. Nat Commun 2021; 12:7013. [PMID: 34853311 PMCID: PMC8636563 DOI: 10.1038/s41467-021-27301-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 11/09/2021] [Indexed: 01/02/2023] Open
Abstract
Post-translational modification of proteins by ubiquitin and ubiquitin-like modifiers, such as SUMO, are key events in protein homeostasis or DNA damage response. Smc5/6 is a nuclear multi-subunit complex that participates in the recombinational DNA repair processes and is required in the maintenance of chromosome integrity. Nse2 is a subunit of the Smc5/6 complex that possesses SUMO E3 ligase activity by the presence of a SP-RING domain that activates the E2~SUMO thioester for discharge on the substrate. Here we present the crystal structure of the SUMO E3 ligase Nse2 in complex with an E2-SUMO thioester mimetic. In addition to the interface between the SP-RING domain and the E2, the complex reveals how two SIM (SUMO-Interacting Motif) -like motifs in Nse2 are restructured upon binding the donor and E2-backside SUMO during the E3-dependent discharge reaction. Both SIM interfaces are essential in the activity of Nse2 and are required to cope with DNA damage. Nse2 is a SUMO E3 ligase component of the Smc5/6 multisubunit complex involved in the DNA repair and chromosome integrity. Here, the structure of the Nse2 in complex with an E2-SUMO thioester mimetic reveals the combined action of two SIM motifs during the E3- dependent conjugation reaction.
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Affiliation(s)
- Nathalia Varejão
- Institut de Biotecnologia i de Biomedicina (IBB) and Dept. de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain
| | - Jara Lascorz
- Institut de Biotecnologia i de Biomedicina (IBB) and Dept. de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain
| | - Joan Codina-Fabra
- IRBLLEIDA, Dept. Ciències Mèdiques Bàsiques, Universitat de Lleida, Lleida, Spain
| | - Gemma Bellí
- IRBLLEIDA, Dept. Ciències Mèdiques Bàsiques, Universitat de Lleida, Lleida, Spain
| | - Helena Borràs-Gas
- Institut de Biotecnologia i de Biomedicina (IBB) and Dept. de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain
| | - Jordi Torres-Rosell
- IRBLLEIDA, Dept. Ciències Mèdiques Bàsiques, Universitat de Lleida, Lleida, Spain
| | - David Reverter
- Institut de Biotecnologia i de Biomedicina (IBB) and Dept. de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain.
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29
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Structural Diversity of Ubiquitin E3 Ligase. Molecules 2021; 26:molecules26216682. [PMID: 34771091 PMCID: PMC8586995 DOI: 10.3390/molecules26216682] [Citation(s) in RCA: 92] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Revised: 10/29/2021] [Accepted: 11/02/2021] [Indexed: 11/17/2022] Open
Abstract
The post-translational modification of proteins regulates many biological processes. Their dysfunction relates to diseases. Ubiquitination is one of the post-translational modifications that target lysine residue and regulate many cellular processes. Three enzymes are required for achieving the ubiquitination reaction: ubiquitin-activating enzyme (E1), ubiquitin-conjugating enzyme (E2), and ubiquitin ligase (E3). E3s play a pivotal role in selecting substrates. Many structural studies have been conducted to reveal the molecular mechanism of the ubiquitination reaction. Recently, the structure of PCAF_N, a newly categorized E3 ligase, was reported. We present a review of the recent progress toward the structural understanding of E3 ligases.
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30
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McPherson KS, Korzhnev DM. Targeting protein-protein interactions in the DNA damage response pathways for cancer chemotherapy. RSC Chem Biol 2021; 2:1167-1195. [PMID: 34458830 PMCID: PMC8342002 DOI: 10.1039/d1cb00101a] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Accepted: 06/20/2021] [Indexed: 12/11/2022] Open
Abstract
Cellular DNA damage response (DDR) is an extensive signaling network that orchestrates DNA damage recognition, repair and avoidance, cell cycle progression and cell death. DDR alteration is a hallmark of cancer, with the deficiency in one DDR capability often compensated by a dependency on alternative pathways endowing cancer cells with survival and growth advantage. Targeting these DDR pathways has provided multiple opportunities for the development of cancer therapies. Traditional drug discovery has mainly focused on catalytic inhibitors that block enzyme active sites, which limits the number of potential drug targets within the DDR pathways. This review article describes the emerging approach to the development of cancer therapeutics targeting essential protein-protein interactions (PPIs) in the DDR network. The overall strategy for the structure-based design of small molecule PPI inhibitors is discussed, followed by an overview of the major DNA damage sensing, DNA repair, and DNA damage tolerance pathways with a specific focus on PPI targets for anti-cancer drug design. The existing small molecule inhibitors of DDR PPIs are summarized that selectively kill cancer cells and/or sensitize cancers to front-line genotoxic therapies, and a range of new PPI targets are proposed that may lead to the development of novel chemotherapeutics.
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Affiliation(s)
- Kerry Silva McPherson
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center Farmington CT 06030 USA +1 860 679 3408 +1 860 679 2849
| | - Dmitry M Korzhnev
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center Farmington CT 06030 USA +1 860 679 3408 +1 860 679 2849
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31
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Signaling Pathways Regulated by UBR Box-Containing E3 Ligases. Int J Mol Sci 2021; 22:ijms22158323. [PMID: 34361089 PMCID: PMC8346999 DOI: 10.3390/ijms22158323] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 07/28/2021] [Accepted: 07/29/2021] [Indexed: 12/31/2022] Open
Abstract
UBR box E3 ligases, also called N-recognins, are integral components of the N-degron pathway. Representative N-recognins include UBR1, UBR2, UBR4, and UBR5, and they bind destabilizing N-terminal residues, termed N-degrons. Understanding the molecular bases of their substrate recognition and the biological impact of the clearance of their substrates on cellular signaling pathways can provide valuable insights into the regulation of these pathways. This review provides an overview of the current knowledge of the binding mechanism of UBR box N-recognin/N-degron interactions and their roles in signaling pathways linked to G-protein-coupled receptors, apoptosis, mitochondrial quality control, inflammation, and DNA damage. The targeting of these UBR box N-recognins can provide potential therapies to treat diseases such as cancer and neurodegenerative diseases.
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32
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Kimura A, Arakawa N, Kagawa H, Kimura Y, Hirano H. Phosphorylation of Ser1452 on BRG1 inhibits the function of the SWI/SNF complex in chromatin activation. J Proteomics 2021; 247:104319. [PMID: 34237461 DOI: 10.1016/j.jprot.2021.104319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 06/16/2021] [Accepted: 06/30/2021] [Indexed: 11/17/2022]
Abstract
BRG1, one of core subunits of the SWI/SNF chromatin remodeling complex, is frequently mutated in cancers. Previously, we reported significant downregulation of the phosphorylation level of BRG1 on Ser1452 (<10%) in cell lines derived from ovarian clear cell carcinoma with frequent recurrence and acquired drug resistance. In this study, we tried to elucidate the roles of BRG1 phosphorylation, using cell lines expressing wild-type, phosphorylation-mimic (brg1-S1452D), or non-phosphorylatable (brg1-S1452A) BRG1. Quantitative proteomic analyses revealed upregulation of proteins and phosphoproteins related to linker histone H1s, histone methylation, and protein ubiquitylation in brg1-S1452D cells, which may coordinately promote the chromatin inactivation and ubiquitin-dependent degradation of target proteins. Consistent with these results, brg1-S1452D cells exhibited an increase in condensed chromatin and polyubiquitylated proteins. In brg1-S1452D cells, we also detected downregulation of various cancer-related proteins (e.g., EGFR and MET) as well as decreased migration, proliferation, and sensitivity to taxanes and oxaliplatin. Together, our results reveal that BRG1 phosphorylation drives tumor malignancy by inhibiting the functions of SWI/SNF complex in chromatin activation, thereby promoting expression of various cancer-related proteins. SIGNIFICANCE: For the first time we demonstrated that the mutation on Ser1452 phosphorylation site of BRG1, a component of SWI/SNF chromatin remodeling complex, changed protein and phosphoprotein levels of linker histone H1s, binding competitor of histone H1s, and histone methylase/demethylase involved in the heterochromatic histone modifications to promote the chromatin inactivation. In phosphorylation-mimic mutant, significant decrease of various cancer-related proteins as well as migration, proliferation, and sensitivity to specific antitumor agents were detected. Our results reveal that BRG1 phosphorylation drives tumor malignancy by inhibiting the functions of SWI/SNF complex in chromatin activation, thereby promoting expression of various cancer-related proteins.
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Affiliation(s)
- Ayuko Kimura
- Advanced Medical Research Center, Yokohama City University and Graduate School of Medical Life Science, Yokohama City University, Fukuura 3-9, Kanazawa-ku, Yokohama, Kanagawa 236-0004, Japan; Graduate School of Health Science, Gunma Paz University, Tonyamachi 1-7-1, Takasaki City, Gunma 370-0006, Japan.
| | - Noriaki Arakawa
- Advanced Medical Research Center, Yokohama City University and Graduate School of Medical Life Science, Yokohama City University, Fukuura 3-9, Kanazawa-ku, Yokohama, Kanagawa 236-0004, Japan; Division of Medicinal Safety Science, National Institute of Health Sciences, Kawasaki, Tonomachi 3-25-26, Kawasaki-ku, Kawasaki City, Kanagawa 210-9501, Japan
| | - Hiroyuki Kagawa
- Advanced Medical Research Center, Yokohama City University and Graduate School of Medical Life Science, Yokohama City University, Fukuura 3-9, Kanazawa-ku, Yokohama, Kanagawa 236-0004, Japan
| | - Yayoi Kimura
- Advanced Medical Research Center, Yokohama City University and Graduate School of Medical Life Science, Yokohama City University, Fukuura 3-9, Kanazawa-ku, Yokohama, Kanagawa 236-0004, Japan
| | - Hisashi Hirano
- Advanced Medical Research Center, Yokohama City University and Graduate School of Medical Life Science, Yokohama City University, Fukuura 3-9, Kanazawa-ku, Yokohama, Kanagawa 236-0004, Japan; Graduate School of Health Science, Gunma Paz University, Tonyamachi 1-7-1, Takasaki City, Gunma 370-0006, Japan
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33
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Osborne HC, Irving E, Forment JV, Schmidt CK. E2 enzymes in genome stability: pulling the strings behind the scenes. Trends Cell Biol 2021; 31:628-643. [PMID: 33685796 DOI: 10.1016/j.tcb.2021.01.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 01/27/2021] [Accepted: 01/29/2021] [Indexed: 02/06/2023]
Abstract
Ubiquitin and ubiquitin-like proteins (UBLs) function as critical post-translational modifiers in the maintenance of genome stability. Ubiquitin/UBL-conjugating enzymes (E2s) are responsible, as part of a wider enzymatic cascade, for transferring single moieties or polychains of ubiquitin/UBLs to one or multiple residues on substrate proteins. Recent advances in structural and mechanistic understanding of how ubiquitin/UBL substrate attachment is orchestrated indicate that E2s can exert control over chain topology, substrate-site specificity, and downstream physiological effects to help maintain genome stability. Drug discovery efforts have typically focussed on modulating other members of the ubiquitin/UBL cascades or the ubiquitin-proteasome system. Here, we review the current standing of E2s in genome stability and revisit their potential as pharmacological targets for developing novel anti-cancer therapies.
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Affiliation(s)
- Hugh C Osborne
- Manchester Cancer Research Centre, Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine, and Health, University of Manchester, 555 Wilmslow Road, Manchester M20 4GJ, UK
| | - Elsa Irving
- Bioscience, Oncology R&D, AstraZeneca, Cambridge CB4 0WG, UK
| | - Josep V Forment
- Bioscience, Oncology R&D, AstraZeneca, Cambridge CB4 0WG, UK
| | - Christine K Schmidt
- Manchester Cancer Research Centre, Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine, and Health, University of Manchester, 555 Wilmslow Road, Manchester M20 4GJ, UK.
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34
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Khago D, Fucci IJ, Byrd RA. The Role of Conformational Dynamics in the Recognition and Regulation of Ubiquitination. Molecules 2020; 25:E5933. [PMID: 33333809 PMCID: PMC7765195 DOI: 10.3390/molecules25245933] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 12/07/2020] [Accepted: 12/09/2020] [Indexed: 11/23/2022] Open
Abstract
The ubiquitination pathway is central to many cell signaling and regulatory events. One of the intriguing aspects of the pathway is the combinatorial sophistication of substrate recognition and ubiquitin chain building determinations. The abundant structural and biological data portray several characteristic protein folds among E2 and E3 proteins, and the understanding of the combinatorial complexity that enables interaction with much of the human proteome is a major goal to developing targeted and selective manipulation of the pathway. With the commonality of some folds, there are likely other aspects that can provide differentiation and recognition. These aspects involve allosteric effects and conformational dynamics that can direct recognition and chain building processes. In this review, we will describe the current state of the knowledge for conformational dynamics across a wide timescale, address the limitations of present approaches, and illustrate the potential to make new advances in connecting dynamics with ubiquitination regulation.
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Affiliation(s)
| | | | - Robert Andrew Byrd
- Structural Biophysics Laboratory, Center for Cancer Research, National Cancer Institute, P.O. Box B, Building 538, Frederick, MD 21702-1201, USA; (D.K.); (I.J.F.)
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35
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Li M, Sengupta B, Benkovic SJ, Lee TH, Hedglin M. PCNA Monoubiquitination Is Regulated by Diffusion of Rad6/Rad18 Complexes along RPA Filaments. Biochemistry 2020; 59:4694-4702. [PMID: 33242956 DOI: 10.1021/acs.biochem.0c00849] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Translesion DNA synthesis (TLS) enables DNA replication through damaging modifications to template DNA and requires monoubiquitination of the proliferating cell nuclear antigen (PCNA) sliding clamp by the Rad6/Rad18 complex. This posttranslational modification is critical to cell survival following exposure to DNA-damaging agents and is tightly regulated to restrict TLS to damaged DNA. Replication protein A (RPA), the major single-strand DNA (ssDNA) binding protein complex, forms filaments on ssDNA exposed at TLS sites and plays critical yet undefined roles in regulating PCNA monoubiquitination. Here, we utilize kinetic assays and single-molecule FRET microscopy to monitor PCNA monoubiquitination and Rad6/Rad18 complex dynamics on RPA filaments, respectively. Results reveal that a Rad6/Rad18 complex is recruited to an RPA filament via Rad18·RPA interactions and randomly translocates along the filament. These translocations promote productive interactions between the Rad6/Rad18 complex and the resident PCNA, significantly enhancing monoubiquitination. These results illuminate critical roles of RPA in the specificity and efficiency of PCNA monoubiquitination and represent, to the best of our knowledge, the first example of ATP-independent translocation of a protein complex along a protein filament.
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Affiliation(s)
- Mingjie Li
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Bhaswati Sengupta
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Stephen J Benkovic
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Tae Hee Lee
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Mark Hedglin
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
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36
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Baek K, Scott DC, Schulman BA. NEDD8 and ubiquitin ligation by cullin-RING E3 ligases. Curr Opin Struct Biol 2020; 67:101-109. [PMID: 33160249 DOI: 10.1016/j.sbi.2020.10.007] [Citation(s) in RCA: 100] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 10/04/2020] [Accepted: 10/05/2020] [Indexed: 01/31/2023]
Abstract
RING E3s comprise the largest family of ubiquitin (UB) and ubiquitin-like protein (UBL) ligases. RING E3s typically promote UB or UBL transfer from the active site of an associated E2 enzyme to a distally-recruited substrate. Many RING E3s - including the cullin-RING ligase family - are multifunctional, interacting with various E2s (or other E3s) to target distinct proteins, transfer different UBLs, or to initially modify substrates with UB or subsequently elongate UB chains. Here we consider recent structures of cullin-RING ligases, and their partner E2 enzymes, representing ligation reactions. The studies collectively reveal multimodal mechanisms - interactions between ancillary E2 or E3 domains, post-translational modifications, or auxiliary binding partners - directing cullin-RING E3-E2 enzyme active sites to modify their specific targets.
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Affiliation(s)
- Kheewoong Baek
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried 82152, Germany
| | - Daniel C Scott
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Brenda A Schulman
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried 82152, Germany; Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
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37
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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: 23] [Impact Index Per Article: 4.6] [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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38
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Zhao W, Jin Y, Wu P, Yang J, Chen Y, Yang Q, Huo X, Li J, De W, Chen J, Yang F. LINC00355 induces gastric cancer proliferation and invasion through promoting ubiquitination of P53. Cell Death Discov 2020; 6:99. [PMID: 33083020 PMCID: PMC7544820 DOI: 10.1038/s41420-020-00332-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 08/21/2020] [Accepted: 09/11/2020] [Indexed: 12/24/2022] Open
Abstract
Long noncoding RNAs (LncRNAs) have been reported to play critical roles in gastric cancer, but true biomarkers remain unknown. In this study, we found a new lncRNA LINC00355 that was involved in malignant progression of gastric cancer (GC) and further revealed its role and mechanism. Differentially expressed lncRNAs were identified through bioinformatics, and qRT-PCR was used to validate the expression of LINC00355 in gastric cancer tissues and cells. The biological role of LINC00355 in GC was detected by gene overexpression and knockdown experiments. Subcellular fractionation, qRT-PCR, and FISH were performed to detect the subcellular localization. Co-IP and western blotting were used to study the ubiquitination-mediated regulation of P53 and the expression of the E3 ligases RAD18 and UBE3C. The results showed that LINC00355 was significantly increased in gastric cancer cell lines and patient tissues and closely correlated with late stages, distant metastasis, and poor prognosis of patients. High expression of LINC00355 promoted the proliferation and invasion of gastric cancer cells in vivo and in vitro. Mechanistic studies found that LINC00355 that mainly located in the nucleus, acting as a transcriptional activator, promoted transcription of RAD18 and UBE3C, which both bind to P53 and mediate the ubiquitination and degradation of P53. Furthermore, LINC00355 overexpression enhanced the ubiquitination process, and LINC00355 knockdown alleviated it. These results indicated that LINC00355 induces gastric cancer cell proliferation and invasion by promoting transcription of RAD18 and UBE3C, which mediates ubiquitination of P53 and thereby plays a critical role in survival and tumorigenicity of gastric cancer cells. LINC00355 may represent a new mechanism for GC progression and provide a potential marker for GC diagnosis and treatment.
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Affiliation(s)
- Wenjing Zhao
- Department of Oncology, Nanjing First Hospital, Nanjing Medical University, 210006 Nanjing, People’s Republic of China
| | - Yan Jin
- Department of Oncology, Nanjing First Hospital, Nanjing Medical University, 210006 Nanjing, People’s Republic of China
| | - Peng Wu
- Department of Oncology, Nanjing First Hospital, Nanjing Medical University, 210006 Nanjing, People’s Republic of China
| | - Jian Yang
- Department of Oncology, Nanjing First Hospital, Nanjing Medical University, 210006 Nanjing, People’s Republic of China
| | - Yuanyuan Chen
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Nanjing Medical University, 211166 Nanjing, People’s Republic of China
| | - Qianlu Yang
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Nanjing Medical University, 211166 Nanjing, People’s Republic of China
| | - Xinying Huo
- Department of Oncology, Nanjing First Hospital, Nanjing Medical University, 210006 Nanjing, People’s Republic of China
| | - Juxue Li
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Nanjing Medical University, 211166 Nanjing, People’s Republic of China
| | - Wei De
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Nanjing Medical University, 211166 Nanjing, People’s Republic of China
| | - Jinfei Chen
- Cancer Center, Taikang Xianlin Drum Tower Hospital, Nanjing University School of Medicine, 210046 Nanjing, People’s Republic of China
- Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center for Personalized Cancer Medicine, Nanjing Medical University, 211166 Nanjing, People’s Republic of China
| | - Fen Yang
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Nanjing Medical University, 211166 Nanjing, People’s Republic of China
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Baatar S, Bai T, Yokobori T, Gombodorj N, Nakazawa N, Ubukata Y, Kimura A, Kogure N, Sano A, Sohda M, Sakai M, Tumenjargal A, Ogata K, Kuwano H, Shirabe K, Saeki H. High RAD18 Expression is Associated with Disease Progression and Poor Prognosis in Patients with Gastric Cancer. Ann Surg Oncol 2020; 27:4360-4368. [PMID: 32356270 DOI: 10.1245/s10434-020-08518-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Indexed: 01/08/2023]
Abstract
BACKGROUND RAD18 plays an important role in DNA damage repair by inducing monoubiquitinated PCNA (mUB-PCNA) in both cancer and normal tissues. Previous studies have not determined the significance of RAD18 expression in clinical gastric cancer (GC) samples. Thus, this study aimed to clarify the expression and functional significance of RAD18 in GC. METHODS Overall, 96 resected GC samples were subjected to an immunohistochemical analysis of RAD18. GC cell lines were also subjected to functional RNA interference analyses of RAD18. RESULTS RAD18 expression was predominantly nuclear and was observed at higher levels in GC tissues than in normal tissues. In GC tissues, strong RAD18 expression was associated with progression of lymph node metastasis (p = 0.0001), lymphatic invasion (p = 0.0255), venous invasion (p < 0.0001), recurrence (p = 0.028), and disease stage (p = 0.0253). Moreover, GC patients with high tumor RAD18 expression had shorter overall survival (p = 0.0061) and recurrence-free survival durations (p = 0.035) than those with low tumor RAD18 expression. RAD18 knockdown inhibited GC proliferation and invasiveness and increased chemosensitivity by suppressing mUB-PCNA. CONCLUSIONS RAD18 expression may be a useful marker of progression and poor prognosis of GC. Moreover, therapeutic strategies that target RAD18 might be a novel chemosensitizer to eradicate the refractory GC.
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Affiliation(s)
- Seded Baatar
- Department of General Surgical Science, Graduate School of Medicine, Gunma University, Maebashi, Japan
| | - Tuya Bai
- Department of General Surgical Science, Graduate School of Medicine, Gunma University, Maebashi, Japan
| | - Takehiko Yokobori
- Department of General Surgical Science, Graduate School of Medicine, Gunma University, Maebashi, Japan. .,Research Program for Omics-Based Medical Science, Division of Integrated Oncology Research, Gunma University Initiative for Advanced Research (GIAR), Maebashi, Japan.
| | - Navchaa Gombodorj
- Research Program for Omics-Based Medical Science, Division of Integrated Oncology Research, Gunma University Initiative for Advanced Research (GIAR), Maebashi, Japan.,Department of Radiation Oncology, National Cancer Center of Mongolia, Ulaanbaatar, Mongolia
| | - Nobuhiro Nakazawa
- Department of General Surgical Science, Graduate School of Medicine, Gunma University, Maebashi, Japan
| | - Yasunari Ubukata
- Department of General Surgical Science, Graduate School of Medicine, Gunma University, Maebashi, Japan
| | - Akiharu Kimura
- Department of General Surgical Science, Graduate School of Medicine, Gunma University, Maebashi, Japan
| | - Norimichi Kogure
- Department of General Surgical Science, Graduate School of Medicine, Gunma University, Maebashi, Japan
| | - Akihiko Sano
- Department of General Surgical Science, Graduate School of Medicine, Gunma University, Maebashi, Japan
| | - Makoto Sohda
- Department of General Surgical Science, Graduate School of Medicine, Gunma University, Maebashi, Japan
| | - Makoto Sakai
- Department of General Surgical Science, Graduate School of Medicine, Gunma University, Maebashi, Japan
| | - Amartuvshin Tumenjargal
- Department of Bioimaging and Information Analysis, Graduate School of Medicine, Gunma University, Maebashi, Japan
| | - Kyoichi Ogata
- Department of General Surgical Science, Graduate School of Medicine, Gunma University, Maebashi, Japan
| | - Hiroyuki Kuwano
- Department of General Surgical Science, Graduate School of Medicine, Gunma University, Maebashi, Japan
| | - Ken Shirabe
- Department of General Surgical Science, Graduate School of Medicine, Gunma University, Maebashi, Japan
| | - Hiroshi Saeki
- Department of General Surgical Science, Graduate School of Medicine, Gunma University, Maebashi, Japan
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40
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Sewduth RN, Baietti MF, Sablina AA. Cracking the Monoubiquitin Code of Genetic Diseases. Int J Mol Sci 2020; 21:ijms21093036. [PMID: 32344852 PMCID: PMC7246618 DOI: 10.3390/ijms21093036] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 04/20/2020] [Accepted: 04/23/2020] [Indexed: 12/26/2022] Open
Abstract
Ubiquitination is a versatile and dynamic post-translational modification in which single ubiquitin molecules or polyubiquitin chains are attached to target proteins, giving rise to mono- or poly-ubiquitination, respectively. The majority of research in the ubiquitin field focused on degradative polyubiquitination, whereas more recent studies uncovered the role of single ubiquitin modification in important physiological processes. Monoubiquitination can modulate the stability, subcellular localization, binding properties, and activity of the target proteins. Understanding the function of monoubiquitination in normal physiology and pathology has important therapeutic implications, as alterations in the monoubiquitin pathway are found in a broad range of genetic diseases. This review highlights a link between monoubiquitin signaling and the pathogenesis of genetic disorders.
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Affiliation(s)
- Raj Nayan Sewduth
- VIB-KU Leuven Center for Cancer Biology, VIB, Herestraat 49, 3000 Leuven, Belgium; (R.N.S.); (M.F.B.)
- Department of Oncology, KU Leuven, Herestraat 49, 3000 Leuven, Belgium
| | - Maria Francesca Baietti
- VIB-KU Leuven Center for Cancer Biology, VIB, Herestraat 49, 3000 Leuven, Belgium; (R.N.S.); (M.F.B.)
- Department of Oncology, KU Leuven, Herestraat 49, 3000 Leuven, Belgium
| | - Anna A. Sablina
- VIB-KU Leuven Center for Cancer Biology, VIB, Herestraat 49, 3000 Leuven, Belgium; (R.N.S.); (M.F.B.)
- Department of Oncology, KU Leuven, Herestraat 49, 3000 Leuven, Belgium
- Correspondence:
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41
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Tan W, Murphy VJ, Charron A, van Twest S, Sharp M, Constantinou A, Parker MW, Crismani W, Bythell-Douglas R, Deans AJ. Preparation and purification of mono-ubiquitinated proteins using Avi-tagged ubiquitin. PLoS One 2020; 15:e0229000. [PMID: 32092106 PMCID: PMC7039436 DOI: 10.1371/journal.pone.0229000] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 01/27/2020] [Indexed: 01/13/2023] Open
Abstract
Site-specific conjugation of ubiquitin onto a range of DNA repair proteins regulates their critical functions in the DNA damage response. Biochemical and structural characterization of these functions are limited by an absence of tools for the purification of DNA repair proteins in purely the ubiquitinated form. To overcome this barrier, we designed a ubiquitin fusion protein that is N-terminally biotinylated and can be conjugated by E3 RING ligases onto various substrates. Biotin affinity purification of modified proteins, followed by cleavage of the affinity tag leads to release of natively-mono-ubiquitinated substrates. As proof-of-principle, we applied this method to several substrates of mono-ubiquitination in the Fanconi anemia (FA)-BRCA pathway of DNA interstrand crosslink repair. These include the FANCI:FANCD2 complex, the PCNA trimer and BRCA1 modified nucleosomes. This method provides a simple approach to study the role of mono-ubiquitination in DNA repair or any other mono-ubiquitination signaling pathways.
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Affiliation(s)
- Winnie Tan
- Genome Stability Unit, St. Vincent’s Institute of Medical Research, Fitzroy, Victoria, Australia
- Department of Medicine (St. Vincent’s Health), The University of Melbourne, Victoria, Australia
| | - Vincent J. Murphy
- Genome Stability Unit, St. Vincent’s Institute of Medical Research, Fitzroy, Victoria, Australia
| | - Aude Charron
- Genome Stability Unit, St. Vincent’s Institute of Medical Research, Fitzroy, Victoria, Australia
- National Graduate School of Chemistry of Montpellier (ENSCM), Montpellier, France
| | - Sylvie van Twest
- Genome Stability Unit, St. Vincent’s Institute of Medical Research, Fitzroy, Victoria, Australia
| | - Michael Sharp
- Genome Stability Unit, St. Vincent’s Institute of Medical Research, Fitzroy, Victoria, Australia
| | - Angelos Constantinou
- Institute of Human Genetics (IGH), Centre National de la Recherche Scientifique (CNRS), Université de Montpellier (UM), Montpellier, France
| | - Michael W. Parker
- Structural Biology Unit, St. Vincent’s Institute of Medical Research, Fitzroy, Victoria, Australia
- Bio21 Institute, University of Melbourne, Parkville, Victoria, Australia
| | - Wayne Crismani
- Genome Stability Unit, St. Vincent’s Institute of Medical Research, Fitzroy, Victoria, Australia
- Department of Medicine (St. Vincent’s Health), The University of Melbourne, Victoria, Australia
| | - Rohan Bythell-Douglas
- Genome Stability Unit, St. Vincent’s Institute of Medical Research, Fitzroy, Victoria, Australia
- Department of Medicine (St. Vincent’s Health), The University of Melbourne, Victoria, Australia
| | - Andrew J. Deans
- Genome Stability Unit, St. Vincent’s Institute of Medical Research, Fitzroy, Victoria, Australia
- Department of Medicine (St. Vincent’s Health), The University of Melbourne, Victoria, Australia
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42
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Control of DNA Damage Bypass by Ubiquitylation of PCNA. Genes (Basel) 2020; 11:genes11020138. [PMID: 32013080 PMCID: PMC7074500 DOI: 10.3390/genes11020138] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 01/23/2020] [Accepted: 01/27/2020] [Indexed: 02/01/2023] Open
Abstract
DNA damage leads to genome instability by interfering with DNA replication. Cells possess several damage bypass pathways that mitigate the effects of DNA damage during replication. These pathways include translesion synthesis and template switching. These pathways are regulated largely through post-translational modifications of proliferating cell nuclear antigen (PCNA), an essential replication accessory factor. Mono-ubiquitylation of PCNA promotes translesion synthesis, and K63-linked poly-ubiquitylation promotes template switching. This article will discuss the mechanisms of how these post-translational modifications of PCNA control these bypass pathways from a structural and biochemical perspective. We will focus on the structure and function of the E3 ubiquitin ligases Rad18 and Rad5 that facilitate the mono-ubiquitylation and poly-ubiquitylation of PCNA, respectively. We conclude by reviewing alternative ideas about how these post-translational modifications of PCNA regulate the assembly of the multi-protein complexes that promote damage bypass pathways.
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43
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Chaugule VK, Arkinson C, Rennie ML, Kämäräinen O, Toth R, Walden H. Allosteric mechanism for site-specific ubiquitination of FANCD2. Nat Chem Biol 2019; 16:291-301. [PMID: 31873223 PMCID: PMC7035956 DOI: 10.1038/s41589-019-0426-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 11/05/2019] [Indexed: 01/31/2023]
Abstract
DNA damage repair is implemented by proteins that are coordinated by specialised molecular signals. One such signal in the Fanconi Anemia (FA) DNA-interstrand crosslink repair pathway is the site-specific monoubiquitination of FANCD2 and FANCI. The signal is mediated by a multi-protein FA core complex (FA-CC) however, the mechanics for precise ubiquitination remain elusive. We show that FANCL, the RING-bearing module in FA-CC, allosterically activates its cognate E2 Ube2T to drive site-specific FANCD2 ubiquitination. Unlike typical RING E3 ligases, FANCL catalyses ubiquitination by rewiring Ube2T’s intra-residue network to influence the active site. Consequently, a basic triad unique to Ube2T engages a structured acidic patch near the target lysine on FANCD2. This three-dimensional complementarity, between the E2 active site and substrate surface, induced by FANCL is central to site-specific monoubiquitination in the FA pathway. Furthermore, the allosteric network of Ube2T can be engineered to enhance FANCL catalysed FANCD2-FANCI di-monoubiquitination without compromising site-specificity.
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Affiliation(s)
- Viduth K Chaugule
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK. .,MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences, University of Dundee, Dundee, UK.
| | - Connor Arkinson
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.,MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences, University of Dundee, Dundee, UK
| | - Martin L Rennie
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Outi Kämäräinen
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Rachel Toth
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences, University of Dundee, Dundee, UK
| | - Helen Walden
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK. .,MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences, University of Dundee, Dundee, UK.
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44
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Masuda Y, Masutani C. Spatiotemporal regulation of PCNA ubiquitination in damage tolerance pathways. Crit Rev Biochem Mol Biol 2019; 54:418-442. [PMID: 31736364 DOI: 10.1080/10409238.2019.1687420] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
DNA is constantly exposed to a wide variety of exogenous and endogenous agents, and most DNA lesions inhibit DNA synthesis. To cope with such problems during replication, cells have molecular mechanisms to resume DNA synthesis in the presence of DNA lesions, which are known as DNA damage tolerance (DDT) pathways. The concept of ubiquitination-mediated regulation of DDT pathways in eukaryotes was established via genetic studies in the yeast Saccharomyces cerevisiae, in which two branches of the DDT pathway are regulated via ubiquitination of proliferating cell nuclear antigen (PCNA): translesion DNA synthesis (TLS) and homology-dependent repair (HDR), which are stimulated by mono- and polyubiquitination of PCNA, respectively. Over the subsequent nearly two decades, significant progress has been made in understanding the mechanisms that regulate DDT pathways in other eukaryotes. Importantly, TLS is intrinsically error-prone because of the miscoding nature of most damaged nucleotides and inaccurate replication of undamaged templates by TLS polymerases (pols), whereas HDR is theoretically error-free because the DNA synthesis is thought to be predominantly performed by pol δ, an accurate replicative DNA pol, using the undamaged sister chromatid as its template. Thus, the regulation of the choice between the TLS and HDR pathways is critical to determine the appropriate biological outcomes caused by DNA damage. In this review, we summarize our current understanding of the species-specific regulatory mechanisms of PCNA ubiquitination and how cells choose between TLS and HDR. We then provide a hypothetical model for the spatiotemporal regulation of DDT pathways in human cells.
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Affiliation(s)
- Yuji Masuda
- Department of Genome Dynamics, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan.,Graduate School of Medicine, Nagoya University, Nagoya, Japan
| | - Chikahide Masutani
- Department of Genome Dynamics, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan.,Graduate School of Medicine, Nagoya University, Nagoya, Japan
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45
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In S, Kim YI, Lee JE, Kim J. RNF20/40-mediated eEF1BδL monoubiquitylation stimulates transcription of heat shock-responsive genes. Nucleic Acids Res 2019; 47:2840-2855. [PMID: 30649429 PMCID: PMC6451099 DOI: 10.1093/nar/gkz006] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 12/27/2018] [Accepted: 01/03/2019] [Indexed: 01/02/2023] Open
Abstract
RNF20/40 E3 ubiquitin ligase-mediated histone H2B monoubiquitylation plays important roles in many cellular processes, including transcriptional regulation. However, the multiple defects observed in RNF20-depleted cells suggest additional ubiquitylation targets of RNF20/40 beyond histone H2B. Here, using biochemically defined assays employing purified factors and cell-based analyses, we demonstrate that RNF20/40, in conjunction with its cognate E2 ubiquitin-conjugating enzyme RAD6, monoubiquitylates lysine 381 of eEF1BδL, a heat shock transcription factor. Notably, monoubiquitylation of eEF1BδL increases eEF1BδL accumulation and potentiates recruitment of p-TEFb to the promoter regions of heat shock-responsive genes, leading to enhanced transcription of these genes. We further demonstrate that cooperative physical interactions among eEF1BδL, RNF20/40, and HSF1 synergistically promote expression of heat shock-responsive genes. In addition to identifying eEF1BδL as a novel ubiquitylation target of RNF20/40 and elucidating its function, we provide a molecular mechanism for the cooperative function of distinct transcription factors in heat shock-responsive gene transcription.
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Affiliation(s)
- Suna In
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141, South Korea
| | - Yong-In Kim
- Center for Bioanalysis, Korea Research Institute of Standards and Science, Daejeon 34113, South Korea
| | - J Eugene Lee
- Center for Bioanalysis, Korea Research Institute of Standards and Science, Daejeon 34113, South Korea
| | - Jaehoon Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141, South Korea
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46
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Cao K, Wang H, Fang Y, Wang Y, Wei L, Chen X, Jiang Z, Wei X, Hu Y. Histone Deacetylase 4 Promotes Osteosarcoma Cell Proliferation and Invasion by Regulating Expression of Proliferating Cell Nuclear Antigen. Front Oncol 2019; 9:870. [PMID: 31552187 PMCID: PMC6743440 DOI: 10.3389/fonc.2019.00870] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 08/21/2019] [Indexed: 01/01/2023] Open
Abstract
Background/Aims: Osteosarcoma (OS) is commonly characterized by lower survival rates and high incidences of local recurrence due to its highly aggressive nature and metastatic tendencies. Studies have shown that histone deacetylase 4 (HDAC4) and proliferating cell nuclear antigen (PCNA) are highly expressed in cancers. Nevertheless, the roles of HDAC4 and PCNA in osteosarcoma (OS) remain unclear. This research aimed to study the expression of HDAC4 and PCNA and their relation to cell proliferation and invasion in human OS. Methods: The levels of HDAC4 and PCNA mRNA and protein were tested in human OS and osteochondroma (OC) tissues. The overexpression and knockdown of HDAC4 in OS cell lines were used to determine the effect of HDAC4 on the expression and degradation of PCNA. The effect of HDAC4 on cell proliferation, invasion and apoptosis was also detected. Additionally, we explored the interaction between HDAC4 and PCNA. Results: The results showed that both HDAC4 and PCNA were increased in human OS tissues. Overexpression of the HDAC4 protein increased the protein level of PCNA, had no effect on the PCNA mRNA level, and decreased the level of ubiquitinated PCNA. We found that overexpression of HDAC4 promoted cell proliferation and invasion and inhibited apoptosis. The opposite effects were observed when HDAC4 was knocked down. The results also showed that HDAC4 could bind to PCNA directly. Conclusions: Our findings suggest that HDAC4 could promote OS cell proliferation and invasion by regulating the expression of PCNA. Thus, our research indicates that HDAC4 may be a potential target for therapy in OS.
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Affiliation(s)
- Kun Cao
- Department of Orthopaedics, First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Hao Wang
- Department of Orthopaedics, First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Yueyang Fang
- Department of Orthopaedics, First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Yuan Wang
- Department of Orthopaedics, First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Lei Wei
- Department of Orthopaedics and Department of Surgery, Warren Alpert Medical School of Brown University/Rhode Island Hospital (RIH), Providence, RI, United States
| | - Xi Chen
- Department of Orthopaedics, First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Zheng Jiang
- Department of Orthopaedics, First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Xiaochun Wei
- Shanxi Key Laboratory of Bone and Soft Tissue Injury Repair, Department of Orthopaedics, Second Hospital of Shanxi Medical University, Taiyuan, China
| | - Yong Hu
- Department of Orthopaedics, First Affiliated Hospital of Anhui Medical University, Hefei, China
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47
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Gundogdu M, Walden H. Structural basis of generic versus specific E2-RING E3 interactions in protein ubiquitination. Protein Sci 2019; 28:1758-1770. [PMID: 31340062 DOI: 10.1002/pro.3690] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 07/11/2019] [Accepted: 07/11/2019] [Indexed: 12/21/2022]
Abstract
Protein ubiquitination is a fundamental regulatory component in eukaryotic cell biology, where a cascade of ubiquitin activating (E1), conjugating (E2), and ligating (E3) enzymes assemble distinct ubiquitin signals on target proteins. E2s specify the type of ubiquitin signal generated, while E3s associate with the E2~Ub conjugate and select the substrate for ubiquitination. Thus, producing the right ubiquitin signal on the right target requires the right E2-E3 pair. The question of how over 600 E3s evolved to discriminate between 38 structurally related E2s has therefore been an area of intensive research, and with over 50 E2-E3 complex structures generated to date, the answer is beginning to emerge. The following review discusses the structural basis of generic E2-RING E3 interactions, contrasted with emerging themes that reveal how specificity can be achieved.
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Affiliation(s)
- Mehmet Gundogdu
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Helen Walden
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
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48
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Deol KK, Lorenz S, Strieter ER. Enzymatic Logic of Ubiquitin Chain Assembly. Front Physiol 2019; 10:835. [PMID: 31333493 PMCID: PMC6624479 DOI: 10.3389/fphys.2019.00835] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 06/17/2019] [Indexed: 12/12/2022] Open
Abstract
Protein ubiquitination impacts virtually every biochemical pathway in eukaryotic cells. The fate of a ubiquitinated protein is largely dictated by the type of ubiquitin modification with which it is decorated, including a large variety of polymeric chains. As a result, there have been intense efforts over the last two decades to dissect the molecular details underlying the synthesis of ubiquitin chains by ubiquitin-conjugating (E2) enzymes and ubiquitin ligases (E3s). In this review, we highlight these advances. We discuss the evidence in support of the alternative models of transferring one ubiquitin at a time to a growing substrate-linked chain (sequential addition model) versus transferring a pre-assembled ubiquitin chain (en bloc model) to a substrate. Against this backdrop, we outline emerging principles of chain assembly: multisite interactions, distinct mechanisms of chain initiation and elongation, optimal positioning of ubiquitin molecules that are ultimately conjugated to each other, and substrate-assisted catalysis. Understanding the enzymatic logic of ubiquitin chain assembly has important biomedical implications, as the misregulation of many E2s and E3s and associated perturbations in ubiquitin chain formation contribute to human disease. The resurgent interest in bifunctional small molecules targeting pathogenic proteins to specific E3s for polyubiquitination and subsequent degradation provides an additional incentive to define the mechanisms responsible for efficient and specific chain synthesis and harness them for therapeutic benefit.
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Affiliation(s)
- Kirandeep K Deol
- Department of Chemistry, University of Massachusetts, Amherst, MA, United States
| | - Sonja Lorenz
- Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
| | - Eric R Strieter
- Department of Chemistry, University of Massachusetts, Amherst, MA, United States.,Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, MA, United States
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49
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Liess AKL, Kucerova A, Schweimer K, Yu L, Roumeliotis TI, Diebold M, Dybkov O, Sotriffer C, Urlaub H, Choudhary JS, Mansfeld J, Lorenz S. Autoinhibition Mechanism of the Ubiquitin-Conjugating Enzyme UBE2S by Autoubiquitination. Structure 2019; 27:1195-1210.e7. [PMID: 31230944 DOI: 10.1016/j.str.2019.05.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 05/01/2019] [Accepted: 05/17/2019] [Indexed: 12/16/2022]
Abstract
Ubiquitin-conjugating enzymes (E2s) govern key aspects of ubiquitin signaling. Emerging evidence suggests that the activities of E2s are modulated by posttranslational modifications; the structural underpinnings, however, are largely unclear. Here, we unravel the structural basis and mechanistic consequences of a conserved autoubiquitination event near the catalytic center of E2s, using the human anaphase-promoting complex/cyclosome-associated UBE2S as a model system. Crystal structures we determined of the catalytic ubiquitin carrier protein domain combined with MD simulations reveal that the active-site region is malleable, which permits an adjacent ubiquitin acceptor site, Lys+5, to be ubiquitinated intramolecularly. We demonstrate by NMR that the Lys+5-linked ubiquitin inhibits UBE2S by obstructing its reloading with ubiquitin. By immunoprecipitation, quantitative mass spectrometry, and siRNA-and-rescue experiments we show that Lys+5 ubiquitination of UBE2S decreases during mitotic exit but does not influence proteasomal turnover of this E2. These findings suggest that UBE2S activity underlies inherent regulation during the cell cycle.
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Affiliation(s)
- Anna K L Liess
- Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, 97080 Würzburg, Germany
| | - Alena Kucerova
- Cell Cycle, Biotechnology Center, Technische Universität Dresden, 01307 Dresden, Germany
| | | | - Lu Yu
- Functional Proteomics Group, The Institute of Cancer Research, London SW3 6JB, UK
| | | | - Mathias Diebold
- Institute of Pharmacy and Food Chemistry, University of Würzburg, 97074 Würzburg, Germany
| | - Olexandr Dybkov
- Department for Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, 37077 Göttingen, Germany
| | - Christoph Sotriffer
- Institute of Pharmacy and Food Chemistry, University of Würzburg, 97074 Würzburg, Germany
| | - Henning Urlaub
- Group for Bioanalytical Mass Spectrometry, Max Planck Institute for Biophysical Chemistry, Göttingen, 37077 Göttingen, Germany; Proteomics Service Facility, Georg-August-Universität, Göttingen, 37077 Göttingen, Germany
| | - Jyoti S Choudhary
- Functional Proteomics Group, The Institute of Cancer Research, London SW3 6JB, UK
| | - Jörg Mansfeld
- Cell Cycle, Biotechnology Center, Technische Universität Dresden, 01307 Dresden, Germany.
| | - Sonja Lorenz
- Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, 97080 Würzburg, Germany.
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50
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Regulation of PCNA cycling on replicating DNA by RFC and RFC-like complexes. Nat Commun 2019; 10:2420. [PMID: 31160570 PMCID: PMC6546911 DOI: 10.1038/s41467-019-10376-w] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Accepted: 05/07/2019] [Indexed: 02/03/2023] Open
Abstract
Replication-Factor-C (RFC) and RFC-like complexes (RLCs) mediate chromatin engagement of the proliferating cell nuclear antigen (PCNA). It remains controversial how RFC and RLCs cooperate to regulate PCNA loading and unloading. Here, we show the distinct PCNA loading or unloading activity of each clamp loader. ATAD5-RLC possesses the potent PCNA unloading activity. ATPase motif and collar domain of ATAD5 are crucial for the unloading activity. DNA structures did not affect PCNA unloading activity of ATAD5-RLC. ATAD5-RLC could unload ubiquitinated PCNA. Through single molecule measurements, we reveal that ATAD5-RLC unloaded PCNA through one intermediate state before ATP hydrolysis. RFC loaded PCNA through two intermediate states on DNA, separated by ATP hydrolysis. Replication proteins such as Fen1 could inhibit the PCNA unloading activity of Elg1-RLC, a yeast homolog of ATAD5-RLC in vitro. Our findings provide molecular insights into how PCNA is released from chromatin to finalize DNA replication/repair.
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