1
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Bodrug T, Welsh KA, Bolhuis DL, Paulаkonis E, Martinez-Chacin RC, Liu B, Pinkin N, Bonacci T, Cui L, Xu P, Roscow O, Amann SJ, Grishkovskaya I, Emanuele MJ, Harrison JS, Steimel JP, Hahn KM, Zhang W, Zhong ED, Haselbach D, Brown NG. Time-resolved cryo-EM (TR-EM) analysis of substrate polyubiquitination by the RING E3 anaphase-promoting complex/cyclosome (APC/C). Nat Struct Mol Biol 2023; 30:1663-1674. [PMID: 37735619 PMCID: PMC10643132 DOI: 10.1038/s41594-023-01105-5] [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: 12/20/2022] [Accepted: 08/21/2023] [Indexed: 09/23/2023]
Abstract
Substrate polyubiquitination drives a myriad of cellular processes, including the cell cycle, apoptosis and immune responses. Polyubiquitination is highly dynamic, and obtaining mechanistic insight has thus far required artificially trapped structures to stabilize specific steps along the enzymatic process. So far, how any ubiquitin ligase builds a proteasomal degradation signal, which is canonically regarded as four or more ubiquitins, remains unclear. Here we present time-resolved cryogenic electron microscopy studies of the 1.2 MDa E3 ubiquitin ligase, known as the anaphase-promoting complex/cyclosome (APC/C), and its E2 co-enzymes (UBE2C/UBCH10 and UBE2S) during substrate polyubiquitination. Using cryoDRGN (Deep Reconstructing Generative Networks), a neural network-based approach, we reconstruct the conformational changes undergone by the human APC/C during polyubiquitination, directly visualize an active E3-E2 pair modifying its substrate, and identify unexpected interactions between multiple ubiquitins with parts of the APC/C machinery, including its coactivator CDH1. Together, we demonstrate how modification of substrates with nascent ubiquitin chains helps to potentiate processive substrate polyubiquitination, allowing us to model how a ubiquitin ligase builds a proteasomal degradation signal.
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Affiliation(s)
- Tatyana Bodrug
- Department of Biochemistry and Biophysics and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, USA
- Department of Pharmacology and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, USA
| | - Kaeli A Welsh
- Department of Pharmacology and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, USA
| | - Derek L Bolhuis
- Department of Biochemistry and Biophysics and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, USA
- Department of Pharmacology and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, USA
| | - Ethan Paulаkonis
- Department of Pharmacology and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, USA
| | - Raquel C Martinez-Chacin
- Department of Pharmacology and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, USA
| | - Bei Liu
- Department of Pharmacology and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, USA
- College of Future Technology, National Biomedical Imaging Center, Peking University, Beijing, China
| | - Nicholas Pinkin
- Department of Pharmacology and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, USA
| | - Thomas Bonacci
- Department of Pharmacology and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, USA
| | - Liying Cui
- Department of Pharmacology and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, USA
| | - Pengning Xu
- Department of Pharmacology and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, USA
| | - Olivia Roscow
- Department of Molecular and Cellular Biology, College of Biological Science, University of Guelph, Guelph, Ontario, Canada
| | - Sascha Josef Amann
- Research Institute of Molecular Pathology, Vienna BioCenter, Vienna, Austria
| | - Irina Grishkovskaya
- Research Institute of Molecular Pathology, Vienna BioCenter, Vienna, Austria
| | - Michael J Emanuele
- Department of Pharmacology and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, USA
| | - Joseph S Harrison
- Department of Chemistry, University of the Pacific, Stockton, CA, USA
| | - Joshua P Steimel
- School of Engineering, California Polytechnic State University Humboldt, Arcata, CA, USA
| | - Klaus M Hahn
- Department of Pharmacology and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, USA
| | - Wei Zhang
- Department of Molecular and Cellular Biology, College of Biological Science, University of Guelph, Guelph, Ontario, Canada
| | - Ellen D Zhong
- Department of Computer Science, Princeton University, Princeton, NJ, USA
| | - David Haselbach
- Research Institute of Molecular Pathology, Vienna BioCenter, Vienna, Austria.
| | - Nicholas G Brown
- Department of Pharmacology and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, USA.
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2
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Bolhuis DL, Martinez‐Chacin RC, Welsh KA, Bodrug T, Cui L, Emanuele MJ, Brown NG. Examining the mechanistic relationship of
APC
/
C
CDH1
and its interphase inhibitor
EMI1. Protein Sci 2022; 31:e4324. [DOI: 10.1002/pro.4324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 03/22/2022] [Accepted: 04/06/2022] [Indexed: 11/07/2022]
Affiliation(s)
- Derek L. Bolhuis
- Department of Biochemistry and Biophysics and Lineberger Comprehensive Cancer Center University of North Carolina Chapel Hill North Carolina USA
| | - Raquel C. Martinez‐Chacin
- Department of Pharmacology and Lineberger Comprehensive Cancer Center University of North Carolina Chapel Hill North Carolina USA
| | - Kaeli A. Welsh
- Department of Pharmacology and Lineberger Comprehensive Cancer Center University of North Carolina Chapel Hill North Carolina USA
| | - Tatyana Bodrug
- Department of Biochemistry and Biophysics and Lineberger Comprehensive Cancer Center University of North Carolina Chapel Hill North Carolina USA
| | - Liying Cui
- Department of Pharmacology and Lineberger Comprehensive Cancer Center University of North Carolina Chapel Hill North Carolina USA
| | - Michael J. Emanuele
- Department of Pharmacology and Lineberger Comprehensive Cancer Center University of North Carolina Chapel Hill North Carolina USA
| | - Nicholas G. Brown
- Department of Pharmacology and Lineberger Comprehensive Cancer Center University of North Carolina Chapel Hill North Carolina USA
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3
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Welsh KA, Bolhuis DL, Nederstigt AE, Boyer J, Temple BRS, Bonacci T, Gu L, Ordureau A, Harper JW, Steimel JP, Zhang Q, Emanuele MJ, Harrison JS, Brown NG. Functional conservation and divergence of the helix-turn-helix motif of E2 ubiquitin-conjugating enzymes. EMBO J 2021; 41:e108823. [PMID: 34942047 PMCID: PMC8804933 DOI: 10.15252/embj.2021108823] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 11/22/2021] [Accepted: 11/25/2021] [Indexed: 02/05/2023] Open
Abstract
Polyubiquitination by E2 and E3 enzymes is crucial to cell cycle control, epigenetic regulation, and development. The hallmark of the E2 family is the ubiquitin (Ub)-conjugating (UBC) domain that forms a dynamic thioester conjugate with ubiquitin (E2~Ub). Numerous studies have focused on E2 surfaces, such as the N-terminal and crossover helices, that directly interact with an E3 or the conjugated ubiquitin to stabilize the active, "closed" state of the E2~Ub. However, it remains unclear how other E2 surfaces regulate ubiquitin transfer. Here, we demonstrate the helix-turn-helix (HTH) motif of the UBC tunes the intrinsic polyubiquitination activity through distinct functions in different E2s. Interestingly, the E2HTH motif is repurposed in UBE2S and UBE2R2 to interact with the conjugated or acceptor ubiquitin, respectively, modulating ubiquitin transfer. Furthermore, we propose that Anaphase-Promoting Complex/Cyclosome binding to the UBE2SHTH reduces the conformational space of the flexible E2~Ub, demonstrating an atypical E3-dependent activation mechanism. Altogether, we postulate the E2HTH motif evolved to provide new functionalities that can be harnessed by E3s and permits additional regulation to facilitate specific E2-E3-mediated polyubiquitination.
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Affiliation(s)
- Kaeli A Welsh
- Department of Pharmacology and Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - Derek L Bolhuis
- Department of Biochemistry and Biophysics and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | | | - Joshua Boyer
- Department of Biochemistry and Biophysics and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Brenda R S Temple
- Department of Biochemistry and Biophysics and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.,R L Juliano Structural Bioinformatics Core Facility, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Thomas Bonacci
- Department of Pharmacology and Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - Li Gu
- Department of Chemistry, University of the Pacific, Stockton, CA, USA
| | - Alban Ordureau
- Department of Cell Biology, Blavatnik Institute of Harvard Medical School, Boston, MA, USA
| | - J Wade Harper
- Department of Cell Biology, Blavatnik Institute of Harvard Medical School, Boston, MA, USA
| | - Joshua P Steimel
- Department of Mechanical Engineering, University of the Pacific, Stockton, CA, USA
| | - Qi Zhang
- Department of Biochemistry and Biophysics and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Michael J Emanuele
- Department of Pharmacology and Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - Joseph S Harrison
- Department of Chemistry, University of the Pacific, Stockton, CA, USA
| | - Nicholas G Brown
- Department of Pharmacology and Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC, USA
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4
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Jiang X, Yuan Y, Tang L, Wang J, Liu Q, Zou X, Duan L. Comprehensive Pan-Cancer Analysis of the Prognostic and Immunological Roles of the METTL3/lncRNA-SNHG1/miRNA-140-3p/UBE2C Axis. Front Cell Dev Biol 2021; 9:765772. [PMID: 34858987 PMCID: PMC8631498 DOI: 10.3389/fcell.2021.765772] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 10/15/2021] [Indexed: 01/01/2023] Open
Abstract
Growing evidence has demonstrated that UBE2C plays a critical role in cancer progression, but there is no study focusing on the prognosis, upstream regulation mechanism, and immunological roles of UBE2C across diverse tumor types. In this study, we found that UBE2C was elevated in this human pan-cancer analysis, and high expression of UBE2C was correlated with poor prognosis. In addition, UBE2C expression was markedly associated with tumor mutation burden (TMB), microsatellite instability (MSI), immune cell infiltration, and diverse drug sensitivities. Finally, we showed that the METTL3/SNHG1/miRNA-140-3p axis could potentially regulate UBE2C expression. N(6)-Methyladenosine (m6A) modifications improved the stability of methylated SNHG1 transcripts by decreasing the rate of RNA degradation, which lead to upregulation of SNHG1 in non-small cell lung cancer (NSCLC). In vitro functional experiments showed that SNHG1, as a competing endogenous RNA, sponges miR-140-3p to increase UBE2C expression in NSCLC cell lines. Our study elucidates the clinical importance and regulatory mechanism of the METTL3/SNHG1/miRNA-140-3p/UBE2C axis in NSCLC and provides a prognostic indicator, as well as a promising therapeutic target for patients with NSCLC.
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Affiliation(s)
- Xiulin Jiang
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences and Yunnan Province, Kunming Institute of Zoology, Kunming, China
| | - Yixiao Yuan
- Department of Thoracic Surgery, The Third Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Lin Tang
- Department of Thoracic Surgery, The Third Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Juan Wang
- Department of Thoracic Surgery, The Third Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Qianqian Liu
- Department of Thoracic Surgery, The Third Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Xiaolan Zou
- Department of Thoracic Surgery, The Third Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Lincan Duan
- Department of Thoracic Surgery, The Third Affiliated Hospital of Kunming Medical University, Kunming, China
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5
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Bodrug T, Welsh KA, Hinkle M, Emanuele MJ, Brown NG. Intricate Regulatory Mechanisms of the Anaphase-Promoting Complex/Cyclosome and Its Role in Chromatin Regulation. Front Cell Dev Biol 2021; 9:687515. [PMID: 34109183 PMCID: PMC8182066 DOI: 10.3389/fcell.2021.687515] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 04/26/2021] [Indexed: 02/04/2023] Open
Abstract
The ubiquitin (Ub)-proteasome system is vital to nearly every biological process in eukaryotes. Specifically, the conjugation of Ub to target proteins by Ub ligases, such as the Anaphase-Promoting Complex/Cyclosome (APC/C), is paramount for cell cycle transitions as it leads to the irreversible destruction of cell cycle regulators by the proteasome. Through this activity, the RING Ub ligase APC/C governs mitosis, G1, and numerous aspects of neurobiology. Pioneering cryo-EM, biochemical reconstitution, and cell-based studies have illuminated many aspects of the conformational dynamics of this large, multi-subunit complex and the sophisticated regulation of APC/C function. More recent studies have revealed new mechanisms that selectively dictate APC/C activity and explore additional pathways that are controlled by APC/C-mediated ubiquitination, including an intimate relationship with chromatin regulation. These tasks go beyond the traditional cell cycle role historically ascribed to the APC/C. Here, we review these novel findings, examine the mechanistic implications of APC/C regulation, and discuss the role of the APC/C in previously unappreciated signaling pathways.
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Affiliation(s)
- Tatyana Bodrug
- Department of Biochemistry and Biophysics, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Kaeli A Welsh
- Department of Pharmacology, Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC, United States
| | - Megan Hinkle
- Department of Pharmacology, Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC, United States
| | - Michael J Emanuele
- Department of Pharmacology, Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC, United States
| | - Nicholas G Brown
- Department of Pharmacology, Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC, United States
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6
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Tokumoto T, Hossain MF, Jyoti MMS, Ali MH, Hossain MB, Acharjee M, Rezanujjaman M, Tokumoto M. Two-Step Mechanism of Cyclin B Degradation Initiated by Proteolytic Cleavage with the 26 S Proteasome in Fish. Sci Rep 2020; 10:8924. [PMID: 32488101 PMCID: PMC7265292 DOI: 10.1038/s41598-020-65009-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 04/20/2020] [Indexed: 11/25/2022] Open
Abstract
To complete meiosis II, cyclin B is degraded in a short period by the inactivation of M-phase promoting factor (MPF). Previously, we showed that the destruction of cyclin B was initiated by the ubiquitin-independent proteolytic activity of the 26 S proteasome through an initial cut in the N-terminus of cyclin (at K57 in the case of goldfish cyclin B). We hypothesized that this cut allows cyclin to be ubiquitinated for further destruction by the ubiquitin-dependent proteolytic pathway, which leads to MPF inactivation. In this study, we aimed to identify the ubiquitination site for further degradation. The destruction of cyclin B point mutants in which lysine residues in a lysine-rich stretch following the cut site of cyclin B had been mutated was analyzed. All the lysine point mutants except K57R (a point mutant in which K57 was substituted with arginine) were susceptible to proteolytic cleavage by the 26 S proteasome. However, the degradation of the K77R and K7677R mutants in Xenopus egg extracts was significantly slower than the degradation of other mutants, and a 42 kDa truncated form of cyclin B was detected during the onset of the degradation of these mutants. The truncated form of recombinant cyclin B, an N-terminal truncated cyclin BΔ57 produced as cut by the 26 S proteasome, was not further cleaved by the 26 S proteasome but rather degraded in Xenopus egg extracts. The injection of the K57R, K77R and K7677R cyclin B proteins stopped cleavage in Xenopus embryos. From the results of a series of experiments, we concluded that cyclin B degradation involves a two-step mechanism initiated by initial ubiquitin-independent cleavage by the 26 S proteasome at lysine 57 followed by its ubiquitin-dependent destruction by the 26 S proteasome following ubiquitination at lysine 77.
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Affiliation(s)
- Toshinobu Tokumoto
- Integrated Bioscience Section, Graduate School of Science and Technology, National University Corporation Shizuoka University, Ohya 836, Suruga-ku, Shizuoka, 422-8529, Japan. .,Biological Science Course, Graduate School of Science, National University Corporation, Shizuoka University, Oya 836, Suruga-ku, Shizuoka, 422-8529, Japan.
| | - Md Forhad Hossain
- Biological Science Course, Graduate School of Science, National University Corporation, Shizuoka University, Oya 836, Suruga-ku, Shizuoka, 422-8529, Japan
| | - Md Maisum Sarwar Jyoti
- Biological Science Course, Graduate School of Science, National University Corporation, Shizuoka University, Oya 836, Suruga-ku, Shizuoka, 422-8529, Japan
| | - Md Hasan Ali
- Integrated Bioscience Section, Graduate School of Science and Technology, National University Corporation Shizuoka University, Ohya 836, Suruga-ku, Shizuoka, 422-8529, Japan
| | - Md Babul Hossain
- Department of Bioscience, Faculty of Science, Shizuoka University, Shizuoka, 422, Japan
| | - Mrityunjoy Acharjee
- Integrated Bioscience Section, Graduate School of Science and Technology, National University Corporation Shizuoka University, Ohya 836, Suruga-ku, Shizuoka, 422-8529, Japan
| | - Md Rezanujjaman
- Integrated Bioscience Section, Graduate School of Science and Technology, National University Corporation Shizuoka University, Ohya 836, Suruga-ku, Shizuoka, 422-8529, Japan
| | - Mika Tokumoto
- CREST Research Project, Japan Science and Technology Corporation, Shizuoka, Japan
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7
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Ubiquitin chain-elongating enzyme UBE2S activates the RING E3 ligase APC/C for substrate priming. Nat Struct Mol Biol 2020; 27:550-560. [PMID: 32393902 PMCID: PMC7293561 DOI: 10.1038/s41594-020-0424-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 03/25/2020] [Indexed: 01/19/2023]
Abstract
The interplay between E2 and E3 enzymes regulates the polyubiquitination of substrates in eukaryotes. Among the several RING-domain E3 ligases in humans, many utilize two distinct E2s for polyubiquitination. For example, the cell cycle regulatory E3, human Anaphase-Promoting Complex/Cyclosome (APC/C), relies on UBE2C to prime substrates with ubiquitin (Ub) and UBE2S to extend polyubiquitin chains. However, the potential coordination between these steps in ubiquitin chain formation remains undefined. While numerous studies have unveiled how RING E3s stimulate individual E2s for Ub transfer, here we change perspective to describe a case where the chain-elongating E2 UBE2S feeds back and directly stimulates the E3 APC/C to promote substrate priming and subsequent multiubiquitination by UBE2C. Our work reveals an unexpected paradigm for the mechanisms of RING E3-dependent ubiquitination and for the diverse and complex interrelationship between components of the ubiquitination cascade.
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8
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Curtis NL, Bolanos-Garcia VM. The Anaphase Promoting Complex/Cyclosome (APC/C): A Versatile E3 Ubiquitin Ligase. Subcell Biochem 2019; 93:539-623. [PMID: 31939164 DOI: 10.1007/978-3-030-28151-9_18] [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] [Indexed: 03/25/2023]
Abstract
In the present chapter we discuss the essential roles of the human E3 ubiquitin ligase Anaphase Promoting Complex/Cyclosome (APC/C) in mitosis as well as the emerging evidence of important APC/C roles in cellular processes beyond cell division control such as regulation of genomic integrity and cell differentiation of the nervous system. We consider the potential incipient role of APC/C dysregulation in the pathophysiology of the neurological disorder Alzheimer's disease (AD). We also discuss how certain Deoxyribonucleic Acid (DNA) and Ribonucleic Acid (RNA) viruses take control of the host's cell division regulatory system through harnessing APC/C ubiquitin ligase activity and hypothesise the plausible molecular mechanisms underpinning virus manipulation of the APC/C. We also examine how defects in the function of this multisubunit protein assembly drive abnormal cell proliferation and lastly argue the potential of APC/C as a promising therapeutic target for the development of innovative therapies for the treatment of chronic malignancies such as cancer.
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Affiliation(s)
- Natalie L Curtis
- Faculty of Health and Life Sciences, Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, OX3 0BP, England, UK
| | - Victor M Bolanos-Garcia
- Faculty of Health and Life Sciences, Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, OX3 0BP, England, UK.
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9
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Taming the Beast: Control of APC/C Cdc20-Dependent Destruction. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2017; 82:111-121. [PMID: 29133301 DOI: 10.1101/sqb.2017.82.033712] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The anaphase-promoting complex/cyclosome (APC/C) is a large multisubunit ubiquitin ligase that triggers the metaphase-to-anaphase transition in the cell cycle by targeting the substrates cyclin B and securin for destruction. APC/C activity toward these two key substrates requires the coactivator Cdc20. To ensure that cells enter mitosis and partition their duplicated genome with high accuracy, APC/CCdc20 activity must be tightly controlled. Here, we discuss the mechanisms that regulate APC/CCdc20 activity both before and during mitosis. We focus our discussion primarily on the chromosomal pathways that both accelerate and delay APC/C activation by targeting Cdc20 to opposing fates. The findings discussed provide an overview of how cells control the activation of this major cell cycle regulator to ensure both accurate and timely cell division.
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10
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Alfieri C, Zhang S, Barford D. Visualizing the complex functions and mechanisms of the anaphase promoting complex/cyclosome (APC/C). Open Biol 2017; 7:170204. [PMID: 29167309 PMCID: PMC5717348 DOI: 10.1098/rsob.170204] [Citation(s) in RCA: 104] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 10/10/2017] [Indexed: 12/17/2022] Open
Abstract
The anaphase promoting complex or cyclosome (APC/C) is a large multi-subunit E3 ubiquitin ligase that orchestrates cell cycle progression by mediating the degradation of important cell cycle regulators. During the two decades since its discovery, much has been learnt concerning its role in recognizing and ubiquitinating specific proteins in a cell-cycle-dependent manner, the mechanisms governing substrate specificity, the catalytic process of assembling polyubiquitin chains on its target proteins, and its regulation by phosphorylation and the spindle assembly checkpoint. The past few years have witnessed significant progress in understanding the quantitative mechanisms underlying these varied APC/C functions. This review integrates the overall functions and properties of the APC/C with mechanistic insights gained from recent cryo-electron microscopy (cryo-EM) studies of reconstituted human APC/C complexes.
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Affiliation(s)
- Claudio Alfieri
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Suyang Zhang
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - David Barford
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
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11
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Brown NG, VanderLinden R, Watson ER, Weissmann F, Ordureau A, Wu KP, Zhang W, Yu S, Mercredi PY, Harrison JS, Davidson IF, Qiao R, Lu Y, Dube P, Brunner MR, Grace CRR, Miller DJ, Haselbach D, Jarvis MA, Yamaguchi M, Yanishevski D, Petzold G, Sidhu SS, Kuhlman B, Kirschner MW, Harper JW, Peters JM, Stark H, Schulman BA. Dual RING E3 Architectures Regulate Multiubiquitination and Ubiquitin Chain Elongation by APC/C. Cell 2016; 165:1440-1453. [PMID: 27259151 DOI: 10.1016/j.cell.2016.05.037] [Citation(s) in RCA: 113] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Revised: 04/16/2016] [Accepted: 05/09/2016] [Indexed: 11/25/2022]
Abstract
Protein ubiquitination involves E1, E2, and E3 trienzyme cascades. E2 and RING E3 enzymes often collaborate to first prime a substrate with a single ubiquitin (UB) and then achieve different forms of polyubiquitination: multiubiquitination of several sites and elongation of linkage-specific UB chains. Here, cryo-EM and biochemistry show that the human E3 anaphase-promoting complex/cyclosome (APC/C) and its two partner E2s, UBE2C (aka UBCH10) and UBE2S, adopt specialized catalytic architectures for these two distinct forms of polyubiquitination. The APC/C RING constrains UBE2C proximal to a substrate and simultaneously binds a substrate-linked UB to drive processive multiubiquitination. Alternatively, during UB chain elongation, the RING does not bind UBE2S but rather lures an evolving substrate-linked UB to UBE2S positioned through a cullin interaction to generate a Lys11-linked chain. Our findings define mechanisms of APC/C regulation, and establish principles by which specialized E3-E2-substrate-UB architectures control different forms of polyubiquitination.
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Affiliation(s)
- Nicholas G Brown
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Ryan VanderLinden
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA; Howard Hughes Medical Institute, Memphis, TN 38105, USA
| | - Edmond R Watson
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Florian Weissmann
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), 1030 Vienna, Austria
| | - Alban Ordureau
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Kuen-Phon Wu
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Wei Zhang
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, Ontario M5S3E1, Canada
| | - Shanshan Yu
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Peter Y Mercredi
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Joseph S Harrison
- Department of Biochemistry and Biophysics and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599, USA
| | - Iain F Davidson
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), 1030 Vienna, Austria
| | - Renping Qiao
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), 1030 Vienna, Austria
| | - Ying Lu
- Department of Systems Biology, Harvard Medical School, Boston, MA, 02115, USA
| | - Prakash Dube
- Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Michael R Brunner
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Christy R R Grace
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Darcie J Miller
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - David Haselbach
- Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Marc A Jarvis
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), 1030 Vienna, Austria
| | - Masaya Yamaguchi
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - David Yanishevski
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Georg Petzold
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), 1030 Vienna, Austria
| | - Sachdev S Sidhu
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, Ontario M5S3E1, Canada
| | - Brian Kuhlman
- Department of Biochemistry and Biophysics and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599, USA
| | - Marc W Kirschner
- Department of Systems Biology, Harvard Medical School, Boston, MA, 02115, USA
| | - J Wade Harper
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Jan-Michael Peters
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), 1030 Vienna, Austria.
| | - Holger Stark
- Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany.
| | - Brenda A Schulman
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA; Howard Hughes Medical Institute, Memphis, TN 38105, USA.
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12
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RING E3 mechanism for ubiquitin ligation to a disordered substrate visualized for human anaphase-promoting complex. Proc Natl Acad Sci U S A 2015; 112:5272-9. [PMID: 25825779 DOI: 10.1073/pnas.1504161112] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
For many E3 ligases, a mobile RING (Really Interesting New Gene) domain stimulates ubiquitin (Ub) transfer from a thioester-linked E2∼Ub intermediate to a lysine on a remotely bound disordered substrate. One such E3 is the gigantic, multisubunit 1.2-MDa anaphase-promoting complex/cyclosome (APC), which controls cell division by ubiquitinating cell cycle regulators to drive their timely degradation. Intrinsically disordered substrates are typically recruited via their KEN-box, D-box, and/or other motifs binding to APC and a coactivator such as CDH1. On the opposite side of the APC, the dynamic catalytic core contains the cullin-like subunit APC2 and its RING partner APC11, which collaborates with the E2 UBCH10 (UBE2C) to ubiquitinate substrates. However, how dynamic RING-E2∼Ub catalytic modules such as APC11-UBCH10∼Ub collide with distally tethered disordered substrates remains poorly understood. We report structural mechanisms of UBCH10 recruitment to APC(CDH1) and substrate ubiquitination. Unexpectedly, in addition to binding APC11's RING, UBCH10 is corecruited via interactions with APC2, which we visualized in a trapped complex representing an APC(CDH1)-UBCH10∼Ub-substrate intermediate by cryo-electron microscopy, and in isolation by X-ray crystallography. To our knowledge, this is the first structural view of APC, or any cullin-RING E3, with E2 and substrate juxtaposed, and it reveals how tripartite cullin-RING-E2 interactions establish APC's specificity for UBCH10 and harness a flexible catalytic module to drive ubiquitination of lysines within an accessible zone. We propose that multisite interactions reduce the degrees of freedom available to dynamic RING E3-E2∼Ub catalytic modules, condense the search radius for target lysines, increase the chance of active-site collision with conformationally fluctuating substrates, and enable regulation.
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13
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Sivakumar S, Gorbsky GJ. Spatiotemporal regulation of the anaphase-promoting complex in mitosis. Nat Rev Mol Cell Biol 2015; 16:82-94. [PMID: 25604195 DOI: 10.1038/nrm3934] [Citation(s) in RCA: 198] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The appropriate timing of events that lead to chromosome segregation during mitosis and cytokinesis is essential to prevent aneuploidy, and defects in these processes can contribute to tumorigenesis. Key mitotic regulators are controlled through ubiquitylation and proteasome-mediated degradation. The APC/C (anaphase-promoting complex; also known as the cyclosome) is an E3 ubiquitin ligase that has a crucial function in the regulation of the mitotic cell cycle, particularly at the onset of anaphase and during mitotic exit. Co-activator proteins, inhibitor proteins, protein kinases and phosphatases interact with the APC/C to temporally and spatially control its activity and thus ensure accurate timing of mitotic events.
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Affiliation(s)
- Sushama Sivakumar
- Cell Cycle and Cancer Biology, Oklahoma Medical Research Foundation, 825 NE 13th Street, Oklahoma City, Oklahoma 73104, USA
| | - Gary J Gorbsky
- Cell Cycle and Cancer Biology, Oklahoma Medical Research Foundation, 825 NE 13th Street, Oklahoma City, Oklahoma 73104, USA
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14
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Wang ST, Li DZ, Li JM, Fang J, Li HZ, Tong PJ, Liu FC. Lentivirus-mediated RNA interference targeting UbcH10 reduces cell growth and invasion of human osteosarcoma cells via inhibition of Ki-67 and matrix metalloproteinases. Oncol Lett 2015; 9:2171-2176. [PMID: 26137034 DOI: 10.3892/ol.2015.3023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 02/10/2015] [Indexed: 11/06/2022] Open
Abstract
Osteosarcoma (OS) is the most commonly diagnosed primary malignancy affecting the bone. UbcH10 is a cancer-related E2-ubiquitin-conjugating enzyme. An overexpression of UbcH10 is significantly associated with tumor grade and cellular proliferation. However, limited evidence exists with regard to the biological function of UbcH10 in OS. The present study created a UbcH10 knockdown OS cell line using lentivirus-mediated RNA interference. The expression of UbcH10 was significantly reduced in UbcH10-targeted small hairpin RNA-expressing lentivirus OS cells. The downregulation of UbcH10 suppressed OS cell proliferation and colony formation ability via decreased Ki-67 expression. UbcH10 knockdown OS cells exhibited impaired invasion and migration abilities. Furthermore, knockdown of UbcH10 led to decreased levels of matrix metalloproteinase-3 and -9 in OS cells. The present study demonstrated the role of UbcH10 in OS cell proliferation, invasion and migration, which suggests that UbcH10 may be a potential candidate for OS therapy.
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Affiliation(s)
- Shan-Tao Wang
- Department of Orthopedics, Qilu Hospital, Shandong University, Jinan, Shandong 510012, P.R. China ; Department of Orthopedics, Yidu Central Hospital of Weifang, Qingzhou, Shandong 262500, P.R. China
| | - Dan-Zhi Li
- Department of Orthopedics, Yidu Central Hospital of Weifang, Qingzhou, Shandong 262500, P.R. China
| | - Jian-Min Li
- Department of Orthopedics, Qilu Hospital, Shandong University, Jinan, Shandong 510012, P.R. China
| | - Jun Fang
- Department of Orthopedics, Yidu Central Hospital of Weifang, Qingzhou, Shandong 262500, P.R. China
| | - Hua-Zhuang Li
- Department of Orthopedics, Yidu Central Hospital of Weifang, Qingzhou, Shandong 262500, P.R. China
| | - Pei-Jian Tong
- Department of Orthopedics, The First Affiliated Hospital of Zhejiang University of Traditional Chinese Medicine, Hangzhou, Zhejiang 310006, P.R. China
| | - Fu-Cun Liu
- Department of Orthopedics, The First Affiliated Hospital of Zhejiang University of Traditional Chinese Medicine, Hangzhou, Zhejiang 310006, P.R. China
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15
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Yamaguchi M, Yu S, Qiao R, Weissmann F, Miller DJ, VanderLinden R, Brown NG, Frye JJ, Peters JM, Schulman BA. Structure of an APC3-APC16 complex: insights into assembly of the anaphase-promoting complex/cyclosome. J Mol Biol 2014; 427:1748-64. [PMID: 25490258 DOI: 10.1016/j.jmb.2014.11.020] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2014] [Revised: 11/14/2014] [Accepted: 11/15/2014] [Indexed: 01/05/2023]
Abstract
The anaphase-promoting complex/cyclosome (APC/C) is a massive E3 ligase that controls mitosis by catalyzing ubiquitination of key cell cycle regulatory proteins. The APC/C assembly contains two subcomplexes: the "Platform" centers around a cullin-RING-like E3 ligase catalytic core; the "Arc Lamp" is a hub that mediates transient association with regulators and ubiquitination substrates. The Arc Lamp contains the small subunits APC16, CDC26, and APC13, and tetratricopeptide repeat (TPR) proteins (APC7, APC3, APC6, and APC8) that homodimerize and stack with quasi-2-fold symmetry. Within the APC/C complex, APC3 serves as center for regulation. APC3's TPR motifs recruit substrate-binding coactivators, CDC20 and CDH1, via their C-terminal conserved Ile-Arg (IR) tail sequences. Human APC3 also binds APC16 and APC7 and contains a >200-residue loop that is heavily phosphorylated during mitosis, although the basis for APC3 interactions and whether loop phosphorylation is required for ubiquitination are unclear. Here, we map the basis for human APC3 assembly with APC16 and APC7, report crystal structures of APC3Δloop alone and in complex with the C-terminal domain of APC16, and test roles of APC3's loop and IR tail binding surfaces in APC/C-catalyzed ubiquitination. The structures show how one APC16 binds asymmetrically to the symmetric APC3 dimer and, together with biochemistry and prior data, explain how APC16 recruits APC7 to APC3, show how APC3's C-terminal domain is rearranged in the full APC/C assembly, and visualize residues in the IR tail binding cleft important for coactivator-dependent ubiquitination. Overall, the results provide insights into assembly, regulation, and interactions of TPR proteins and the APC/C.
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Affiliation(s)
- Masaya Yamaguchi
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Shanshan Yu
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Renping Qiao
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), 1030 Vienna, Austria
| | - Florian Weissmann
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), 1030 Vienna, Austria
| | - Darcie J Miller
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Ryan VanderLinden
- Howard Hughes Medical Institute, St. Jude Children's Research Hospital, Memphis, TN 38105 USA
| | - Nicholas G Brown
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Jeremiah J Frye
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Jan-Michael Peters
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), 1030 Vienna, Austria
| | - Brenda A Schulman
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA; Howard Hughes Medical Institute, St. Jude Children's Research Hospital, Memphis, TN 38105 USA.
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16
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Shafiee SM, Seghatoleslam A, Nikseresht M, Hosseini SV, Alizadeh-Naeeni M, Safaei A, Owji AA. Expression Status of UBE2Q2 in Colorectal Primary Tumors and Cell Lines. IRANIAN JOURNAL OF MEDICAL SCIENCES 2014; 39:196-202. [PMID: 24753643 PMCID: PMC3993048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Revised: 02/11/2013] [Accepted: 02/23/2013] [Indexed: 11/26/2022]
Abstract
BACKGROUND Activation of the ubiquitin-proteasome pathway in various malignancies, including colorectal cancer, is established. This pathway mediates the degradation of damaged proteins and regulates growth and stress response. The novel human gene, UBE2Q2, with a putative ubiquitin-conjugating enzyme activity, is reported to be overexpressed in some malignancies. We sought to investigate the expression levels of the UBE2Q2 gene in colorectal cell lines as well as in cancerous and normal tissues from patients with colorectal cancer. METHODS Levels of UBE2Q2 mRNA in cell lines were assessed by Real-Time PCR. Western blotting was employed to investigate the levels of the UBE2Q2 protein in 8 colorectal cell lines and 43 colorectal tumor samples. RESULTS Expression of UBE2Q2 was observed at the level of both mRNA and protein in colorectal cell lines, HT29/219, LS180, SW742, Caco2, HTC116, SW48, SW480, and SW1116. Increased levels of UBE2Q2 immunoreactivity was observed in the 65.11% (28 out of 43) of the colorectal carcinoma tissues when compared with their corresponding normal tissues. Difference between the mean intensities of UBE2Q2 bands from cancerous and normal tissues was statistically significant at P<0.001 (paired t test). CONCLUSION We showed the expression pattern of the novel human gene, UBE2Q2, in 8 colorectal cell lines. Overexpression of UBE2Q2 in the majority of the colorectal carcinoma samples denotes that it may have implications for the pathogenesis of colorectal cancer.
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Affiliation(s)
- Sayed Mohammad Shafiee
- Department of Biochemistry-Recombinant Protein Laboratory, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran;
| | - Atefeh Seghatoleslam
- Department of Biochemistry-Recombinant Protein Laboratory, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran;
| | - Mohsen Nikseresht
- Cellular and Molecular Research Center, Yasuj University of Medical Sciences, Yasuj, Iran;
| | - Seyed Vahid Hosseini
- Colorectal Research Center, Shahid Faghihi Hospital, Nemazee Hospital, Shiraz University of Medical Sciences, Shiraz, Iran;
| | - Mahvash Alizadeh-Naeeni
- Department of Internal Medicine, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran;
| | - Akbar Safaei
- Department of Pathology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran;
| | - Ali Akbar Owji
- Department of Biochemistry-Recombinant Protein Laboratory, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran;
,Endocrine and Metabolism Research Center, Nemazee Hospital, Shiraz University of Medical Sciences, Shiraz, Iran
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17
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Xie C, Powell C, Yao M, Wu J, Dong Q. Ubiquitin-conjugating enzyme E2C: a potential cancer biomarker. Int J Biochem Cell Biol 2013; 47:113-7. [PMID: 24361302 DOI: 10.1016/j.biocel.2013.11.023] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Accepted: 11/28/2013] [Indexed: 10/25/2022]
Abstract
The ubiquitin-conjugating enzymes 2C (UBE2C) is an integral component of the ubiquitin proteasome system. UBE2C consists of a conserved core domain containing the catalytic Cys residue and an N-terminal extension. The core domain is required for ubiquitin adduct formation by interacting with the ubiquitin-fold domain in the E1 enzyme, and contributes to the E3 enzyme binding. UBE2C N-terminal extension regulates E3 enzyme activity as a part of an intrinsic inhibitory mechanism. UBE2C is required for the destruction of mitotic cyclins and securin, which are essential for spindle assembly checkpoint and mitotic exit. The UBE2C mRNA and/or protein levels are aberrantly increased in many cancer types with poor clinical outcomes. Accumulation of UBE2C stimulates cell proliferation and anchorage-independent growth. UBE2C transgenic mice are prone to develop spontaneous tumors and carcinogen-induced tumor with evidence of chromosome aneuploidy.
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Affiliation(s)
- Chanlu Xie
- School of Science and Health, The University of Western Sydney, Australia
| | - Chris Powell
- School of Science and Health, The University of Western Sydney, Australia
| | - Mu Yao
- Central Clinical School and Bosch Institute, The University of Sydney and Department of Endocrinology, Royal Prince Alfred Hospital, Sydney, Australia
| | - Jianmin Wu
- The Kinghorn Cancer Centre & Cancer Division, Garvan Institute of Medical Research, Sydney, Australia; St Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - Qihan Dong
- School of Science and Health, The University of Western Sydney, Australia; Central Clinical School and Bosch Institute, The University of Sydney and Department of Endocrinology, Royal Prince Alfred Hospital, Sydney, Australia.
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18
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UBE2Q1 expression in human colorectal tumors and cell lines. Mol Biol Rep 2013; 40:7045-51. [PMID: 24197692 DOI: 10.1007/s11033-013-2824-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Accepted: 10/25/2013] [Indexed: 12/31/2022]
Abstract
Colorectal cancer is the third most common cancer in the world. Ubiquitin-proteasome system has shown to be activated in colorectal and other malignancies. UBE2Q1 is a novel human gene that encodes a putative E2 ubiquitin conjugating enzyme. Here, we investigated the expression pattern of UBE2Q1 gene in cell lines and tissues from human colorectal tumors. Quantitative (q) RT-PCR were employed to evaluate the expression levels of the mRNA for UBE2Q1 in colorectal cancer cell lines (HT29/219, LS180, SW742, Caco2, HTC116, SW48, SW480 and SW1116). Expression of UBE2Q1 at the protein levels were assessed by Western blotting in cell lines as well as in 43 human colorectal tumor tissues. All cell lines tested expressed UBE2Q1 gene at the level of both mRNA and protein, with the SW1116 line representing the lowest level of expression. The cell lines HT29/219 and SW742 showed the highest levels of UBE2Q1 protein and mRNA respectively. When compared to corresponding normal tissues, malignant parts of colorectal tumors showed increased levels of UBE2Q1 immunoreactivity in 32 (74.42 %) of cases. These data suggest that UBE2Q1 is differentially expressed in colorectal cell lines and shows overexpression in colorectal tumors.
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19
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Electron microscopy structure of human APC/C(CDH1)-EMI1 reveals multimodal mechanism of E3 ligase shutdown. Nat Struct Mol Biol 2013; 20:827-35. [PMID: 23708605 PMCID: PMC3742808 DOI: 10.1038/nsmb.2593] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Accepted: 04/09/2013] [Indexed: 12/20/2022]
Abstract
The Anaphase Promoting Complex/Cyclosome (APC/C) is a ~1.5 MDa multiprotein E3 ligase enzyme that regulates cell division by promoting timely ubiquitin-mediated proteolysis of key cell cycle regulatory proteins. Inhibition of human APC/CCDH1 during interphase by Early Mitotic Inhibitor 1 (EMI1) is essential for accurate coordination of DNA synthesis and mitosis. Here, we report a hybrid structural approach involving NMR, electron microscopy, and enzymology, which reveal that EMI1’s 143-residue C-terminal domain inhibits multiple APC/CCDH1 functions. The intrinsically disordered D-box, Linker, and Tail elements, together with a structured zinc-binding domain, bind distinct regions of APC/CCDH1 to synergistically both block the substrate-binding site and inhibit ubiquitin chain elongation. The functional importance of intrinsic structural disorder is explained by enabling a small inhibitory domain to bind multiple sites to shut down multiple functions of a “molecular machine” nearly 100 times its size.
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20
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Jiang BJ, Zhan XL, Fu CZ, Wang HB, Cheng G, Zan LS. Identification of ANAPC13 gene polymorphisms associated with body measurement traits in Bos taurus. GENETICS AND MOLECULAR RESEARCH 2012; 11:2862-70. [PMID: 22782628 DOI: 10.4238/2012.june.15.6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Body measurement traits, influenced by genes and environmental factors, play numerous important roles in the value assessment of productivity and economy. There has been some indication that ANAPC13 influences adult height. We used PCR-SSCP and DNA sequencing technology to identify polymorphisms in the ANAPC13 gene. A polymorphism in intron 1 (A > G at base 17) was identified and an additional polymorphic site (C > T at base 42) was also uncovered, which accompanied the previous polymorphism in more than 98% of the subjects. The two novel polymorphisms in exon 1 were assayed and potential associations with body measurement traits were evaluated in 404 individuals. Three genotypes were detected in the study group, named AACC, AGCT and GGTT. Significant differences were observed between genotypes AACC and AGCT for body length, withers height, hip height, hip width, heart girth, pin bone width. However, no associations were found among any genotypes and chest depth. We conclude that polymorphisms and mutations in non-coding regions of the ANAPC13 gene significantly affect body measurement traits.
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Affiliation(s)
- B J Jiang
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, P.R. China
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21
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Cotto-Rios XM, Jones MJK, Busino L, Pagano M, Huang TT. APC/CCdh1-dependent proteolysis of USP1 regulates the response to UV-mediated DNA damage. ACTA ACUST UNITED AC 2011; 194:177-86. [PMID: 21768287 PMCID: PMC3144416 DOI: 10.1083/jcb.201101062] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
APC/CCdh1-dependent degradation of USP1 allows for PCNA monoubiquitination and subsequent recruitment of trans-lesion synthesis polymerase to UV repair sites. Targeted protein destruction of critical cellular regulators during the G1 phase of the cell cycle is achieved by anaphase-promoting complex/cyclosomeCdh1 (APC/CCdh1), a multisubunit E3 ubiquitin ligase. Cells lacking Cdh1 have been shown to accumulate deoxyribonucleic acid (DNA) damage, suggesting that it may play a previously unrecognized role in maintaining genomic stability. The ubiquitin-specific protease 1 (USP1) is a known critical regulator of DNA repair and genomic stability. In this paper, we report that USP1 was degraded in G1 via APC/CCdh1. USP1 levels were kept low in G1 to provide a permissive condition for inducing proliferating cell nuclear antigen (PCNA) monoubiquitination in response to ultraviolet (UV) damage before DNA replication. Importantly, expression of a USP1 mutant that cannot be degraded via APC/CCdh1 inhibited PCNA monoubiquitination during G1, likely compromising the recruitment of trans-lesion synthesis polymerase to UV repair sites. Thus, we propose a role for APC/CCdh1 in modulating the status of PCNA monoubiquitination and UV DNA repair before S phase entry.
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Affiliation(s)
- Xiomaris M Cotto-Rios
- Department of Biochemistry, New York University School of Medicine, New York, NY 10016, USA
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22
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Fang X, Ma H, Lu D, Yu H, Lai W, Ruan S. Comparative proteomics analysis of proteins expressed in the I-1 and I-2 internodes of strawberry stolons. Proteome Sci 2011; 9:26. [PMID: 21569547 PMCID: PMC3113925 DOI: 10.1186/1477-5956-9-26] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Accepted: 05/14/2011] [Indexed: 01/09/2023] Open
Abstract
Background Strawberries (Fragaria ananassa) reproduce asexually through stolons, which have strong tendencies to form adventitious roots at their second node. Understanding how the development of the proximal (I-1) and distal (I-2) internodes of stolons differ should facilitate nursery cultivation of strawberries. Results Herein, we compared the proteomic profiles of the strawberry stolon I-1 and I-2 internodes. Proteins extracted from the internodes were separated by two-dimensional gel electrophoresis, and 164 I-1 protein spots and 200 I-2 protein spots were examined further. Using mass spectrometry and database searches, 38 I-1 and 52 I-2 proteins were identified and categorized (8 and 10 groups, respectively) according to their cellular compartmentalization and functionality. Many of the identified proteins are enzymes necessary for carbohydrate metabolism and photosynthesis. Furthermore, identification of proteins that interact revealed that many of the I-2 proteins form a dynamic network during development. Finally, given our results, we present a mechanistic scheme for adventitious root formation of new clonal plants at the second node. Conclusions Comparative proteomic analysis of I-1 and I-2 proteins revealed that the ubiquitin-proteasome pathway and sugar-hormone pathways might be important during adventitious root formation at the second node of new clonal plants.
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Affiliation(s)
- Xianping Fang
- Laboratory of Plant Molecular Biology and Proteomics, Institute of Biology, Hangzhou Academy of Agricultural Sciences, Hangzhou 310024, China.
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23
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Meyer HJ, Rape M. Processive ubiquitin chain formation by the anaphase-promoting complex. Semin Cell Dev Biol 2011; 22:544-50. [PMID: 21477659 DOI: 10.1016/j.semcdb.2011.03.009] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Accepted: 03/16/2011] [Indexed: 12/11/2022]
Abstract
Progression through mitosis requires the sequential ubiquitination of cell cycle regulators by the anaphase-promoting complex, resulting in their proteasomal degradation. Although several mechanisms contribute to APC/C regulation during mitosis, the APC/C is able to discriminate between its many substrates by exploiting differences in the processivity of ubiquitin chain assembly. Here, we discuss how the APC/C achieves processive ubiquitin chain formation to trigger the sequential degradation of cell cycle regulators during mitosis.
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Affiliation(s)
- Hermann-Josef Meyer
- University of California at Berkeley, Department of Molecular and Cell Biology, Berkeley, CA 94720-3202, United States
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Moshe Y, Bar-On O, Ganoth D, Hershko A. Regulation of the action of early mitotic inhibitor 1 on the anaphase-promoting complex/cyclosome by cyclin-dependent kinases. J Biol Chem 2011; 286:16647-57. [PMID: 21454540 DOI: 10.1074/jbc.m111.223339] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cell cycle regulation is characterized by alternating activities of cyclin-dependent kinases (CDKs) and of the ubiquitin ligase anaphase promoting complex/cyclosome (APC/C). During S-phase APC/C is inhibited by early mitotic inhibitor 1 (Emi1) to allow the accumulation of cyclins A and B and to prevent re-replication. Emi1 is degraded at prophase by a Plk1-dependent pathway. Recent studies in which the degradation pathway of Emi1 was disrupted have shown that APC/C is activated at mitotic entry despite stabilization of Emi1. These results suggested the possibility of additional mechanisms other than degradation of Emi1, which release APC/C from inhibition by Emi1 upon entry into mitosis. In this study we report one such mechanism, by which the ability of Emi1 to inhibit APC/C is negatively regulated by CDKs. We show that in Plk1-inhibited cells Emi1 is stabilized and phosphorylated, that Emi1 is phosphorylated by CDKs in mitotic but not S-phase cell extracts, and that Emi1 phosphorylation by mitotic cell extracts or purified CDKs markedly reduces the ability of Emi1 to bind and to inhibit APC/C. Finally, we show that the addition of extracts from S-phase cells to extracts from mitotic cells protects Emi1 from CDK-mediated inactivation.
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Affiliation(s)
- Yakir Moshe
- Unit of Biochemistry, the Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel
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25
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Seher A, Nickel J, Mueller TD, Kneitz S, Gebhardt S, ter Vehn TM, Schlunck G, Sebald W. Gene expression profiling of connective tissue growth factor (CTGF) stimulated primary human tenon fibroblasts reveals an inflammatory and wound healing response in vitro. Mol Vis 2011; 17:53-62. [PMID: 21245951 PMCID: PMC3021567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2010] [Accepted: 01/04/2011] [Indexed: 11/23/2022] Open
Abstract
PURPOSE The biologic relevance of human connective tissue growth factor (hCTGF) for primary human tenon fibroblasts (HTFs) was investigated by RNA expression profiling using affymetrix(TM) oligonucleotide array technology to identify genes that are regulated by hCTGF. METHODS Recombinant hCTGF was expressed in HEK293T cells and purified by affinity and gel chromatography. Specificity and biologic activity of hCTGF was confirmed by biosensor interaction analysis and proliferation assays. For RNA expression profiling HTFs were stimulated with hCTGF for 48h and analyzed using affymetrix(TM) oligonucleotide array technology. Results were validated by real time RT-PCR. RESULTS hCTGF induces various groups of genes responsible for a wound healing and inflammatory response in HTFs. A new subset of CTGF inducible inflammatory genes was discovered (e.g., chemokine [C-X-C motif] ligand 1 [CXCL1], chemokine [C-X-C motif] ligand 6 [CXCL6], interleukin 6 [IL6], and interleukin 8 [IL8]). We also identified genes that can transmit the known biologic functions initiated by CTGF such as proliferation and extracellular matrix remodelling. Of special interest is a group of genes, e.g., osteoglycin (OGN) and osteomodulin (OMD), which are known to play a key role in osteoblast biology. CONCLUSIONS This study specifies the important role of hCTGF for primary tenon fibroblast function. The RNA expression profile yields new insights into the relevance of hCTGF in influencing biologic processes like wound healing, inflammation, proliferation, and extracellular matrix remodelling in vitro via transcriptional regulation of specific genes. The results suggest that CTGF potentially acts as a modulating factor in inflammatory and wound healing response in fibroblasts of the human eye.
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Affiliation(s)
- Axel Seher
- Universitätsklinikum Würzburg, Abteilung für Molekulare Innere Medizin, Würzburg, Germany.
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Abstract
AbstractThe complex molecular events responsible for coordinating chromosome replication and segregation with cell division and growth are collectively known as the cell cycle. Progression through the cell cycle is orchestrated by the interplay between controlled protein synthesis and degradation and protein phosphorylation. Protein degradation is primarily regulated through the ubiquitin proteasome system, mediated by two related E3 protein ubiquitin ligases, the Skp1 cullin F-box (SCF) and the anaphase promoting complex (also known as the cyclosome) (APC/C). The APC/C is a multi-subunit cullin-RING E3 ubiquitin ligase that regulates progression through the mitotic phase of the cell cycle and controls entry into S phase by catalysing the ubiquitylation of cyclins and other cell cycle regulatory proteins. Selection of APC/C targets is controlled through recognition of short destruction motifs, predominantly the D-box and KEN-box. APC/C-mediated coordination of cell cycle progression is achieved through the temporal regulation of APC/C activity and substrate specificity, exerted through a combination of co-activator subunits, reversible phosphorylation and inhibitory proteins and complexes. The aim of this article is to discuss the APC/C from a structural and mechanistic perspective. Although an atomic structure of the APC/C is still lacking, a combination of genetic, biochemical, electron microscopy studies of intact APC/C and crystallographic analysis of individual subunits, together with analogies to evolutionarily related E3 ligases of the RING family, has provided deep insights into the molecular mechanisms of catalysis and substrate recognition, and structural organisation of the APC/C.
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Chen SM, Jiang CY, Wu JY, Liu B, Chen YJ, Hu CJ, Liu XX. RNA interference-mediated silencing of UBCH10 gene inhibits colorectal cancer cell growthin vitroandin vivo. Clin Exp Pharmacol Physiol 2010. [DOI: 10.1111/j.1440-1681.2010.05348.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Kops GJPL, van der Voet M, van der Voet M, Manak MS, van Osch MHJ, Naini SM, Brear A, McLeod IX, Hentschel DM, Yates JR, van den Heuvel S, Shah JV. APC16 is a conserved subunit of the anaphase-promoting complex/cyclosome. J Cell Sci 2010; 123:1623-33. [PMID: 20392738 DOI: 10.1242/jcs.061549] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Error-free chromosome segregation depends on timely activation of the multi-subunit E3 ubiquitin ligase APC/C. Activation of the APC/C initiates chromosome segregation and mitotic exit by targeting critical cell-cycle regulators for destruction. The APC/C is the principle target of the mitotic checkpoint, which prevents segregation while chromosomes are unattached to spindle microtubules. We now report the identification and characterization of APC16, a conserved subunit of the APC/C. APC16 was found in association with tandem-affinity-purified mitotic checkpoint complex protein complexes. APC16 is a bona fide subunit of human APC/C: it is present in APC/C complexes throughout the cell cycle, the phenotype of APC16-depleted cells copies depletion of other APC/C subunits, and APC16 is important for APC/C activity towards mitotic substrates. APC16 sequence homologues can be identified in metazoans, but not fungi, by four conserved primary sequence stretches. We provide evidence that the C. elegans gene K10D2.4 and the D. rerio gene zgc:110659 are functional equivalents of human APC16. Our findings show that APC/C is composed of previously undescribed subunits, and raise the question of why metazoan APC/C is molecularly different from unicellular APC/C.
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Affiliation(s)
- Geert J P L Kops
- Department of Physiological Chemistry and Cancer Genomics Centre, UMC Utrecht, Utrecht, The Netherlands.
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Hershko A. From rabbit reticulocytes to clam oocytes: in search of the system that targets mitotic cyclins for degradation. Mol Biol Cell 2010; 21:1645-7. [PMID: 20335505 PMCID: PMC2869371 DOI: 10.1091/mbc.e09-07-0583] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
By the late 1980s, the basic biochemistry of ubiquitin-mediated protein degradation had already been elucidated by studies that used reticulocyte lysates. However, the scope and biological functions of this system remained largely obscure. Therefore, I became interested at that time in the mechanisms by which mitotic cyclins are degraded in exit from mitosis. Using a cell-free system from clam oocytes that faithfully reproduced cell cycle stage-specific degradation of cyclins, we identified in 1995 a large ubiquitin ligase complex that targets mitotic cyclins for degradation. Subsequent studies in many laboratories showed that this ubiquitin ligase, now called the anaphase-promoting complex/cyclosome, has centrally important roles in many aspects of cell cycle control.
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Affiliation(s)
- Avram Hershko
- Unit of Biochemistry, the Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.
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30
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Sequence characterization and promoter identification of porcine APC10 gene. Mol Biol Rep 2010; 37:3841-9. [PMID: 20232159 DOI: 10.1007/s11033-010-0040-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2009] [Accepted: 02/24/2010] [Indexed: 10/19/2022]
Abstract
APC10 protein, a subunit of the anaphase-promoting complex (APC), plays an essential role in the progression of cells from mitosis to G1. In this study, we cloned and sequenced partial cDNA, intron 1 and 5'-flanking sequences of porcine APC10. The partial cDNA is 595 bp long and has an open reading frame of 558 bp which encodes 185 putative amino acids. Real-time PCR analysis revealed that the porcine APC10 mRNA expression shows a wide distribution and expression levels varies within a small different range in detected tissues. The deduced protein has a high identity with other eight species and comprises a conserved DOC domain. The phylogenetic tree indicated that porcine APC10 has the closest genetic relationship with human, monkey and dog. Promoter activity was demonstrated by transient transfection of 5'-deletion promoter/luciferase constructs into PK15 cells, and indicated that the proximal region from -2,052 to -1,764 is necessary for basal promoter activity. Positive cis-regulatory elements are present from -2,544 to -2,052 and from -3,114 to -2,774, while negative cis-regulatory elements may be present from -2,774 to -2,544. Yeast one-hybrid assay revealed Sp1 can interact with proximal promoter region of porcine APC10.
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UBE2S drives elongation of K11-linked ubiquitin chains by the anaphase-promoting complex. Proc Natl Acad Sci U S A 2010; 107:1355-60. [PMID: 20080579 DOI: 10.1073/pnas.0912802107] [Citation(s) in RCA: 184] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The Anaphase-Promoting Complex (APC) is an E3 ubiquitin ligase that regulates mitosis and G1 by sequentially targeting cell-cycle regulators for ubiquitination and proteasomal degradation. The mechanism of ubiquitin chain formation by APC and the resultant chain topology remains controversial. By using a single-lysine APC substrate to dissect the topology of ubiquitinated substrates, we find that APC-catalyzed ubiquitination has an intrinsic preference for the K11 linkage of ubiquitin that is essential for substrate degradation. K11 specificity is determined by an E2 enzyme, UBE2S/E2-EPF, that elongates ubiquitin chains after the substrates are pre-ubiquitinated by UbcH10 or UbcH5. UBE2S copurifies with APC; dominant-negative Ube2S slows down APC substrate degradation in functional cell-cycle extracts. We propose that Ube2S is a critical, unique component of the APC ubiquitination pathway.
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Chen D, Wang Q, Huang H, Xia L, Jiang X, Kan L, Sun Q, Chen D. Effete-mediated degradation of Cyclin A is essential for the maintenance of germline stem cells in Drosophila. Development 2009; 136:4133-42. [PMID: 19906849 DOI: 10.1242/dev.039032] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Increasing evidence supports the idea that the regulation of stem cells requires both extrinsic and intrinsic mechanisms. However, much less is known about how intrinsic signals regulate the fate of stem cells. Studies on germline stem cells (GSCs) in the Drosophila ovary have provided novel insights into the regulatory mechanisms of stem cell maintenance. In this study, we demonstrate that a ubiquitin-dependent pathway mediated by the Drosophila eff gene, which encodes the E2 ubiquitin-conjugating enzyme Effete (Eff), plays an essential role in GSC maintenance. We show that Eff both physically and genetically interacts with dAPC2, a key component of the anaphase-promoting complex (APC), which acts as a multisubunit E3 ligase and plays an essential role in targeting mitotic regulators for degradation during exit from mitosis. This interaction indicates that Eff regulates the APC/C-mediated proteolysis pathway in GSCs. Moreover, we show that expression of a stable form of Cyclin A, but not full-length Cyclin A, results in GSC loss. Finally we show that, in common with APC2, Eff is required for the ubiquitylation of Cyclin A, and overexpression of full-length Cyclin A accelerates the loss of GSCs in the eff mutant background. Collectively, our data support the idea that Effete/APC-mediated degradation of Cyclin A is essential for the maintenance of germline stem cells in Drosophila. Given that the regulation of mitotic Cyclins is evolutionarily conserved between flies and mammals, our study also implies that a similar mechanism may be conserved in mammals.
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Affiliation(s)
- Dongsheng Chen
- State Key Laboratory of Reproductive Biology and State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Datun Road, Chaoyang, Beijing 100101, P.R. China
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Garnett MJ, Mansfeld J, Godwin C, Matsusaka T, Wu J, Russell P, Pines J, Venkitaraman AR. UBE2S elongates ubiquitin chains on APC/C substrates to promote mitotic exit. Nat Cell Biol 2009; 11:1363-9. [PMID: 19820702 PMCID: PMC2875106 DOI: 10.1038/ncb1983] [Citation(s) in RCA: 208] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2009] [Accepted: 09/29/2009] [Indexed: 02/07/2023]
Abstract
The anaphase-promoting complex (APC/C), a ubiquitin ligase, is the target of the spindle-assembly checkpoint (SAC), and it ubiquitylates protein substrates whose degradation regulates progress through mitosis. The identity of the ubiquitin-conjugating (E2) enzymes that work with the APC/C is unclear. In an RNA interference (RNAi) screen for factors that modify release from drug-induced SAC activation, we identified the E2 enzyme UBE2S as an APC/C auxiliary factor that promotes mitotic exit. UBE2S is dispensable in a normal mitosis, but its depletion prolongs drug-induced mitotic arrest and suppresses mitotic slippage. In vitro, UBE2S elongates ubiquitin chains initiated by the E2 enzymes UBCH10 and UBCH5, enhancing the degradation of APC/C substrates by the proteasome. Indeed, following release from SAC-induced mitotic arrest, UBE2S-depleted cells neither degrade crucial APC/C substrates, nor silence this checkpoint, whereas bypassing the SAC through BUBR1 depletion or Aurora-B inhibition negates the requirement for UBE2S. Thus, UBE2S functions with the APC/C in a two-step mechanism to control substrate ubiquitylation that is essential for mitotic exit after prolonged SAC activation, providing a new model for APC/C function in human cells.
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Affiliation(s)
- Mathew J Garnett
- University of Cambridge, Department of Oncology and The Medical Research Council Cancer Cell Unit, Hutchison/MRC Research Centre, Hills Road, Cambridge, CB2 OXZ, UK
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Chen S, Chen Y, Hu C, Jing H, Cao Y, Liu X. Association of clinicopathological features with UbcH10 expression in colorectal cancer. J Cancer Res Clin Oncol 2009; 136:419-26. [PMID: 19779934 DOI: 10.1007/s00432-009-0672-7] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2009] [Accepted: 08/17/2009] [Indexed: 12/27/2022]
Abstract
PURPOSE UbcH10 is the cancer-related E2 ubiquitin-conjugating enzyme, and its overexpression has been demonstrated in a variety of malignancies. The aim of this study is to investigate the association of UbcH10 gene expression with the carcinogenesis and tumor progression of colorectal cancer. METHODS The expression levels of UbcH10 in human malignant colorectal carcinoma tissues and their adjacent normal tissues were examined using real-time quantitative RT-PCR and immunohistochemical analysis. The correlations of UbcH10 expression to the clinicalpathologic characteristics of the colorectal cancer were analyzed. Cell proliferation and Matrigel invasion assays were performed in HT-29 cells transfected with UbcH10 expression plasmid pcDNA3.1-UbcH10, UbcH10 RNA interference vector pUbcH10-RNAi as well as their control vectors. RESULTS Our study demonstrated that the expression of UbcH10 in colorectal carcinoma tissues was significantly higher than that in non-cancerous tissues (P < 0.01), and the UbcH10 overexpression was related to the degree of tumor differentiation and lymph node metastasis of colorectal cancer patients (P < 0.05). In vitro, the overexpression of UbcH10 promoted cell proliferation and tumor invasiveness, but the downregulation of UbcH10 expression significantly reduced the growth rate and the invasiveness activity of tumor cell line. CONCLUSIONS Our study suggests that the overexpression of UbcH10 gene plays a critical role in the carcinogenesis and tumor progression of colorectal cancer. It may be a new marker in diagnosis and prognosis of colorectal cancer, and the inhibition of UbcH10 may be a therapeutic potential for the treatment of colorectal cancer.
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Affiliation(s)
- Shimin Chen
- Institute of Biochemistry and Molecular Biology, Shandong University School of Medicine, 44#, Wenhua Xi Road, 250012, Jinan, Shandong, China
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35
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Analysis of genes differentially expressed during initial cellular dedifferentiation in cotton. ACTA ACUST UNITED AC 2008. [DOI: 10.1007/s11434-008-0468-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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36
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Walker A, Acquaviva C, Matsusaka T, Koop L, Pines J. UbcH10 has a rate-limiting role in G1 phase but might not act in the spindle checkpoint or as part of an autonomous oscillator. J Cell Sci 2008; 121:2319-26. [PMID: 18559889 DOI: 10.1242/jcs.031591] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Ubiquitin-dependent proteolysis mediated by the anaphase-promoting complex/cyclosome (APC/C) ubiquitin ligase lies at the heart of the cell cycle. The APC/C targets mitotic cyclins for destruction in mitosis and G1 phase and is then inactivated at S phase, thereby generating the alternating states of high and low cyclin-Cdk activity required for the alternation of mitosis and DNA replication. Two key questions are how the APC/C is held in check by the spindle-assembly checkpoint to delay cells in mitosis in the presence of improperly attached chromosomes, and how the APC/C is inactivated once cells exit mitosis. The ubiquitin-conjugating protein UbcH10 has been proposed to be crucial in the answers to both questions. However, here we show that the behaviour of UbcH10 is inconsistent with both a crucial role in the spindle checkpoint and in inactivating the APC/C as part of an autonomous oscillator. Instead, we find that the rate-limiting role of UbcH10 is only at the end of G1 phase, just before DNA replication begins.
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Affiliation(s)
- Adam Walker
- Wellcome Trust/Cancer Research UK Gurdon Institute and Department of Zoology, University of Cambridge, Cambridge CB2 1QN, UK
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37
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Rodrigo-Brenni MC, Morgan DO. Sequential E2s drive polyubiquitin chain assembly on APC targets. Cell 2007; 130:127-39. [PMID: 17632060 DOI: 10.1016/j.cell.2007.05.027] [Citation(s) in RCA: 211] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2006] [Revised: 04/09/2007] [Accepted: 05/04/2007] [Indexed: 11/22/2022]
Abstract
The anaphase-promoting complex (APC), or cyclosome, is an E3 ubiquitin-protein ligase that collaborates with E2 ubiquitin-conjugating enzymes to assemble polyubiquitin chains on proteins important for cell-cycle progression. It remains unclear how the APC - or many other E3s - promotes the multiple distinct reactions necessary for chain assembly. We addressed this problem by analyzing APC interactions with different E2s. We screened all budding yeast E2s as APC coenzymes in vitro and found that two, Ubc4 and Ubc1, are the key E2 partners for the APC. These proteins display strikingly different but complementary enzymatic behaviors: Ubc4 supports the rapid monoubiquitination of multiple lysines on APC targets, while Ubc1 catalyzes K48-linked polyubiquitin chain assembly on preattached ubiquitins. Mitotic APC function is lost in yeast strains lacking both Ubc1 and Ubc4. E2-25K, a human homolog of Ubc1, also promotes APC-dependent chain extension on preattached ubiquitins. We propose that sequential E2 proteins catalyze K48-linked polyubiquitination and thus proteasomal destruction of APC targets.
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38
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Banerjee S, Brooks WS, Crawford DF. Inactivation of the ubiquitin conjugating enzyme UBE2Q2 causes a prophase arrest and enhanced apoptosis in response to microtubule inhibiting agents. Oncogene 2007; 26:6509-17. [PMID: 17471241 DOI: 10.1038/sj.onc.1210471] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A putative ubiquitin conjugating enzyme known as UBE2Q2 was previously identified in a microarray screen for mitotic regulatory proteins. UBE2Q2 is very similar to another human protein, UBE2Q1 and orthologs from other higher eukaryotic species. In these studies, we demonstrate that UBE2Q2 can covalently bind ubiquitin on the active site cysteine in vitro and show that inhibition of this protein in vivo causes an early mitotic arrest and increased cytotoxicity when cells are treated with microtubule inhibiting agents (MIAs). Changes in cell cycle progression and viability are not observed in the absence of MIA treatment, indicating that UBE2Q2 is involved in the response to MIAs rather than performing a more general function in mitosis. Inhibition of the UBE2Q2 protein causes cells to undergo a prolonged prophase arrest suggesting that UBE2Q2 normally functions to antagonize an early mitotic checkpoint. Furthermore, UBE2Q2 inhibition sensitizes cells to the cytotoxic effects of MIAs through caspase-mediated apoptosis that is correlated with PARP-1 cleavage. These data provide insights into the cellular response to MIAs and demonstrate that inhibition of UBE2Q2 protein function may be useful in the treatment of malignancies.
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Affiliation(s)
- S Banerjee
- Department of Pediatrics, University of Alabama, Birmingham 35233, USA
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Peters JM. The anaphase promoting complex/cyclosome: a machine designed to destroy. Nat Rev Mol Cell Biol 2006; 7:644-56. [PMID: 16896351 DOI: 10.1038/nrm1988] [Citation(s) in RCA: 982] [Impact Index Per Article: 54.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The anaphase promoting complex/cyclosome (APC/C) is a ubiquitin ligase that has essential functions in and outside the eukaryotic cell cycle. It is the most complex molecular machine that is known to catalyse ubiquitylation reactions, and it contains more than a dozen subunits that assemble into a large 1.5-MDa complex. Recent discoveries have revealed an unexpected multitude of mechanisms that control APC/C activity, and have provided a first insight into how this unusual ubiquitin ligase recognizes its substrates.
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Affiliation(s)
- Jan-Michael Peters
- Research Institute of Molecular Pathology, Dr. Bohr-Gasse 7, A-1030 Vienna, Austria.
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40
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Tokumoto M, Kurita Y, Tokumoto T. Molecular Cloning of cDNA Encoding APC11, a Catalytic Component of Anaphase-promoting-complex (APC/C), from Goldfish ( Carassius auratus), and Establishment of in vitroUbiquitinating System. Zoolog Sci 2006; 23:675-8. [PMID: 16971785 DOI: 10.2108/zsj.23.675] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Destruction of cyclin B is required for exit from mitosis and meiosis. A cyclin-degrading system, including anaphase-promoting-complex/cyclosome (APC/C), has been shown to be responsible for cyclin B destruction. Here we present the cloning, sequencing, and expression analysis of goldfish (Carassius auratus) APC11, which encodes the catalytic component of APC/C from goldfish ovary. The cloned cDNA is 348 bp long and encodes 88 amino acids. The deduced amino acid sequence is highly homologous to APC11 from other species. The expression of mRNA for APC11 was ubiquitous among tissues, as opposed to that of mRNA for E2-C, which occurred at a very high level in the ovary. Recombinant goldfish APC11 possesses ubiquitinating activity against cyclin B. We established an in vitro ubiquitinating system of proteins composed of purified recombinant E1, E2-C, and APC11 from goldfish. The reconstructed system for these ubiquitinating enzymes makes it feasible to elucidate the molecular mechanism of cyclin B degradation.
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Affiliation(s)
- Mika Tokumoto
- Department of Biology and Geosciences, Faculty of Science, National University Corporation Shizuoka University, Japan
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Kirkpatrick DS, Hathaway NA, Hanna J, Elsasser S, Rush J, Finley D, King RW, Gygi SP. Quantitative analysis of in vitro ubiquitinated cyclin B1 reveals complex chain topology. Nat Cell Biol 2006; 8:700-10. [PMID: 16799550 DOI: 10.1038/ncb1436] [Citation(s) in RCA: 348] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2006] [Accepted: 05/15/2006] [Indexed: 11/08/2022]
Abstract
Protein ubiquitination regulates many cellular processes, including protein degradation, signal transduction, DNA repair and cell division. In the classical model, a uniform polyubiquitin chain that is linked through Lys 48 is required for recognition and degradation by the 26S proteasome. Here, we used a reconstituted system and quantitative mass spectrometry to demonstrate that cyclin B1 is modified by ubiquitin chains of complex topology, rather than by homogeneous Lys 48-linked chains. The anaphase-promoting complex was found to attach monoubiquitin to multiple lysine residues on cyclin B1, followed by poly-ubiquitin chain extensions linked through multiple lysine residues of ubiquitin (Lys 63, Lys 11 and Lys 48). These heterogeneous ubiquitin chains were sufficient for binding to ubiquitin receptors, as well as for degradation by the 26S proteasome, even when they were synthesized with mutant ubiquitin that lacked Lys 48. Together, our observations expand the context of what can be considered to be a sufficient degradation signal and provide unique insights into the mechanisms of substrate ubiquitination.
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Affiliation(s)
- Donald S Kirkpatrick
- Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA
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Eytan E, Moshe Y, Braunstein I, Hershko A. Roles of the anaphase-promoting complex/cyclosome and of its activator Cdc20 in functional substrate binding. Proc Natl Acad Sci U S A 2006; 103:2081-6. [PMID: 16455800 PMCID: PMC1413726 DOI: 10.1073/pnas.0510695103] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The anaphase-promoting complex/cyclosome (APC/C) is a multisubunit ubiquitin-protein ligase that targets for degradation cell-cycle regulatory proteins during exit from mitosis and in the G1 phase of the cell cycle. The activity of APC/C in mitosis and in G1 requires interaction with the activator proteins Cdc20 and Cdh1, respectively. Substrates of APC/C-Cdc20 contain a recognition motif called the "destruction box" (D-box). The mode of the action of APC/C activators and their possible role in substrate binding remain poorly understood. Several investigators suggested that Cdc20 and Cdh1 mediate substrate recognition, whereas others proposed that substrates bind to APC/C or to APC/C-activator complexes. All these studies used binding assays, which do not necessarily indicate that substrate binding is functional and leads to product formation. In the present investigation we examined this problem by an "isotope-trapping" approach that directly demonstrates productive substrate binding. With this method we found that the simultaneous presence of both APC/C and Cdc20 is required for functional substrate binding. By contrast, with conventional binding assays we found that either Cdc20 or APC/C can bind substrate by itself, but only at low affinity and relaxed selectivity for D-box. Our results are consistent with models in which interaction of substrate with specific binding sites on both APC/C and Cdc20 is involved in selective and productive substrate binding.
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Affiliation(s)
- Esther Eytan
- Unit of Biochemistry, Rappaport Faculty of Medicine, Technion–Israel Institute of Technology, Haifa 31096, Israel
| | - Yakir Moshe
- Unit of Biochemistry, Rappaport Faculty of Medicine, Technion–Israel Institute of Technology, Haifa 31096, Israel
| | - Ilana Braunstein
- Unit of Biochemistry, Rappaport Faculty of Medicine, Technion–Israel Institute of Technology, Haifa 31096, Israel
| | - Avram Hershko
- Unit of Biochemistry, Rappaport Faculty of Medicine, Technion–Israel Institute of Technology, Haifa 31096, Israel
- *To whom correspondence should be addressed. E-mail:
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Máthé E, Kraft C, Giet R, Deák P, Peters JM, Glover DM. The E2-C vihar is required for the correct spatiotemporal proteolysis of cyclin B and itself undergoes cyclical degradation. Curr Biol 2005; 14:1723-33. [PMID: 15458643 DOI: 10.1016/j.cub.2004.09.023] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2004] [Revised: 07/08/2004] [Accepted: 08/02/2004] [Indexed: 10/26/2022]
Abstract
BACKGROUND Proteolytic degradation of mitotic regulatory proteins first requires these targets to be ubiquitinated. This is regulated at the level of conjugation of ubiquitin to substrates by the anaphase-promoting complex/cyclosome (APC/C) ubiquitin-protein ligase. Substrate specificity and temporal activity of the APC/C has been thought to lie primarily with its two activators, Cdc20/Fizzy and Cdh1/Fizzy-related. RESULTS Here, we show that reduction in the E2 ubiquitin-conjugating enzyme (UBC) of the E2-C family that is encoded by the Drosophila gene vihar (vih), by either mutation or RNAi, leads to an accumulation of cells in a metaphase-like state. Cyclin B accumulates to high levels in all mitotic vih cells, particularly at the spindle poles. Vihar E2-C is present in the cytoplasm of mitotic cells but also associates with centrosomes, and its own degradation is initiated at the metaphase-anaphase transition. Expression of destruction D box mutants of vihar in the syncytial embryo results in mitotic arrest at late anaphase. In contrast to hypomorphic mutants, Cyclin B is degraded at the spindle poles and accumulates in the equatorial region of the spindle. CONCLUSIONS In Drosophila, the Vihar E2 UBC contributes to the spatiotemporal control of Cyclin B degradation that first occurs at the spindle poles. APC/C-mediated proteolysis of Vihar E2-C autoinactivates the APC/C at the centrosome before a second wave of proteolysis to degrade Cyclin B on the rest of the spindle and elsewhere in the cell.
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Affiliation(s)
- Endre Máthé
- Cancer Research UK Cell Cycle Genetics Group, Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK
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Passmore LA, Barford D, Harper JW. Purification and Assay of the Budding Yeast Anaphase‐Promoting Complex. Methods Enzymol 2005; 398:195-219. [PMID: 16275330 DOI: 10.1016/s0076-6879(05)98017-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The anaphase-promoting complex (APC) is a central regulator of the eukaryotic cell cycle and functions as an E3 ubiquitin protein ligase to catalyze the ubiquitination of a number of cell cycle regulatory proteins. The APC contains at least 13 subunits in addition to two activator subunits, Cdc20 and Cdh1, that associate with the APC in a cell cycle-dependent manner. This chapter describes methods for preparation and assay of the APC from Saccharomyces cerevisiae. Highly active APC is purified from cells expressing Cdc16 fused with a tandem affinity purification (TAP) tag. Enzymatically active APC is achieved upon addition of recombinant Cdc20 or Cdh1 together with E1, Ubc4, ATP, and ubiquitin. Activity assays toward several endogenous substrates, including Clb2 and Pds1, are described. In addition, methods for observation of APC-coactivator and APC-substrate complexes by native gel electrophoresis are described.
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Affiliation(s)
- Lori A Passmore
- Section of Structural Biology, Institute for Cancer Research, London SW3 6JB, UK
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Salic A, King RW. Identifying Small Molecule Inhibitors of the Ubiquitin‐Proteasome Pathway in Xenopus Egg Extracts. Methods Enzymol 2005; 399:567-85. [PMID: 16338382 DOI: 10.1016/s0076-6879(05)99038-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Small molecule inhibitors of the proteasome have been crucial for dissecting the mechanism of proteasome-dependent protein degradation and identifying substrates of the ubiquitin-proteasome system (UPS). To identify small molecules that block ubiquitin-dependent protein degradation through other mechanisms, we have developed pathway-based screening approaches in Xenopus egg extracts. The regulated degradation of UPS substrates can be reconstituted in these extracts, providing an excellent system in which to perform forward chemical genetic screens. The ability to manipulate extracts biochemically and to compare the activity of small molecules across different assays facilitates the identification of potential target proteins. Here we describe methods for identifying inhibitors of the proteolytic pathways that regulate cell cycle progression and Wnt signaling in Xenopus extracts.
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Debonneville C, Staub O. Participation of the ubiquitin-conjugating enzyme UBE2E3 in Nedd4-2-dependent regulation of the epithelial Na+ channel. Mol Cell Biol 2004; 24:2397-409. [PMID: 14993279 PMCID: PMC355826 DOI: 10.1128/mcb.24.6.2397-2409.2004] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The epithelial Na+ channel (ENaC) is a heteromeric protein complex playing a fundamental role in Na+ homeostasis and blood pressure regulation. Specific mutations inactivating PY motifs in ENaC C termini cause Liddle's syndrome, an inherited form of hypertension. Previously we showed that these PY motifs serve as binding sites for the E3 enzyme Nedd4-2, implying ubiquitination as a regulatory mechanism of ENaC. Ubiquitination involves the sequential action of E1, E2, and E3 enzymes. Here we identify the E2 enzyme UBE2E3, which acts in concert with Nedd4-2, and show by coimmunoprecipitation that UBE2E3 and Nedd4-2 interact together. In Xenopus laevis oocytes, UBE2E3 reduces ENaC activity marginally, consistent with Nedd4-2 being the rate-limiting factor in this process, whereas a catalytically inactive mutant of UBE2E3 (UBE2E3-CS) causes elevated ENaC activity by increasing cell surface expression. No additive effect is observed when UBE2E3-CS is coexpressed with an inactive Nedd4-2 mutant, and the stimulatory role of UBE2E3-CS depends on the integrity of the PY motifs (Nedd4-2 binding sites) and the ubiquitination sites on ENaC. In renal mpkCCD(cl4) cells, displaying ENaC-dependent transepithelial Na+ transport, Nedd4-2 and UBE2E3 can be coimmunoprecipitated and overexpression of UBE2E3 affects Na+ transport, corroborating the concept of a concerted action of UBE2E3 and Nedd4-2 in ENaC regulation.
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Affiliation(s)
- Christophe Debonneville
- Department of Pharmacology and Toxicology, University of Lausanne, CH-1005 Lausanne, Switzerland
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47
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Liu Q, Shang F, Guo W, Hobbs M, Valverde P, Reddy V, Taylor A. Regulation of the ubiquitin proteasome pathway in human lens epithelial cells during the cell cycle. Exp Eye Res 2004; 78:197-205. [PMID: 14729352 DOI: 10.1016/j.exer.2003.11.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Most proliferating cells follow a series of orderly transitions from one phase to another. These transitions are usually controlled by timed degradation of cell cycle regulators by the ubiquitin-proteasome pathway (UPP). There are no published reports regarding the timing of phases of the human lens cell cycle or regarding cell cycle-related changes in UPP components. Objectives of this study were to characterize the timing of the phases of the human lens epithelial cell cycle and to explore potential functions of critical components of the UPP in controlling lens cell cycle. Human lens epithelial cells were synchronized at G0/G1 phase by contact inhibition. Cell cycle progression upon subculturing was monitored by FACS analysis. It took approximately 40 hr for HLEC to complete one cell cycle, approximately 20 hr for G1 phase, approximately 8-10 hr for S phase and approximately 10 hr for the combination of G2 and M phases. Proteasome-dependent degradation of p21WAF and p27Kip, the dominant Cdk inhibitors, was associated with the G1/S phase transition in these cells. Proteasome inhibition experiments indicate that proteolysis is the predominant process which is responsible for the variations in these regulators during the cell cycle. Levels of specific ubiquitin conjugating enzymes, Ubc7 and Ubc10, increased 6 and 2-fold at the G2/M phase and S/G2/M phases, respectively. Levels of these E2s decreased precipitously upon completion of the M phase. In contrast, levels of ubiquitin activating enzyme (E1) and Ubc3 remained constant during the cell cycle. Cul1, a component of the SCF (an E3), remained relatively constant during cell cycle. The up-regulation of Ubc7 and Ubc10 during the G2/M and S/G2/M phases suggests that these enzymes may be involved in controlling the cell cycle progression at this phase. Taken together, the data indicate that expression of key components of the UPP in the human lens epithelial cells is regulated in a cell cycle-dependent manner. Some of the variations in levels of ubiquitin conjugating enzymes are suggestive of previously undescribed functions.
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Affiliation(s)
- Qing Liu
- JM USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA 02111, USA
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Nowicki MO, Pawlowski P, Fischer T, Hess G, Pawlowski T, Skorski T. Chronic myelogenous leukemia molecular signature. Oncogene 2003; 22:3952-63. [PMID: 12813469 DOI: 10.1038/sj.onc.1206620] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
To obtain comprehensive information about the genes involved in BCR/ABL-dependent leukemogenesis, samples from 15 chronic myelogenous leukemia (CML) patients and seven normal donors were analysed using a cDNA microarray assay. After subtraction of the artificial, random or cross-hybridization signals, data about 5315 genes have been effectively analysed in all samples. The assay revealed >/=4-fold difference in the average expression of 263 genes in all CML samples when compared to normal counterparts, with 148 genes being upregulated and 115 being downregulated. Differentially expressed genes include those associated with BCR/ABL-induced abnormalities in signal transduction, gene transactivation, cell cycle, apoptosis, adhesion, DNA repair, differentiation, metabolism and malignant progression. Interestingly, CML-blast crisis cells in peripheral blood differ from those from bone marrow, indicating major changes in gene expression profiles upon entering into the bloodstream. Moreover, BCR/ABL modulates expression of genes, which are involved in regulation of chromosome/chromatin/DNA dynamics during S and M cell cycle phase. Moreover, the ability of CML cells to recognize and respond to a pathogen infection may be compromised. Altogether, this work provides a large body of information regarding gene expression profiles associated with CML and also represents a source of potential targets for CML therapeutics.
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MESH Headings
- Blast Crisis/genetics
- Blast Crisis/metabolism
- Blood Cells/metabolism
- Bone Marrow Cells/metabolism
- Cell Cycle
- Disease Progression
- Fusion Proteins, bcr-abl/genetics
- Gene Expression Profiling
- Gene Expression Regulation, Leukemic
- Humans
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/genetics
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/metabolism
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/pathology
- Neoplasm Proteins/classification
- Neoplasm Proteins/genetics
- Neoplastic Stem Cells/metabolism
- Oligonucleotide Array Sequence Analysis
- Subtraction Technique
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Affiliation(s)
- Michal Oskar Nowicki
- Center for Biotechnology, College of Science and Technology, Temple University, Philadelphia, PA 19122, USA
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Seino H, Kishi T, Nishitani H, Yamao F. Two ubiquitin-conjugating enzymes, UbcP1/Ubc4 and UbcP4/Ubc11, have distinct functions for ubiquitination of mitotic cyclin. Mol Cell Biol 2003; 23:3497-505. [PMID: 12724408 PMCID: PMC164763 DOI: 10.1128/mcb.23.10.3497-3505.2003] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cell cycle events are regulated by sequential activation and inactivation of Cdk kinases. Mitotic exit is accomplished by the inactivation of mitotic Cdk kinase, which is mainly achieved by degradation of cyclins. The ubiquitin-proteasome system is involved in this process, requiring APC/C (anaphase-promoting complex/cyclosome) as a ubiquitin ligase. In Xenopus and clam oocytes, the ubiquitin-conjugating enzymes that function with APC/C have been identified as two proteins, UBC4 and UBCx/E2-C. Previously we reported that the fission yeast ubiquitin-conjugating enzyme UbcP4/Ubc11, a homologue of UBCx/E2-C, is required for mitotic transition. Here we show that the other fission yeast ubiquitin-conjugating enzyme, UbcP1/Ubc4, which is homologous to UBC4, is also required for mitotic transition in the same manner as UbcP4/Ubc11. Both ubiquitin-conjugating enzymes are essential for cell division and directly required for the degradation of mitotic cyclin Cdc13. They function nonredundantly in the ubiquitination of CDC13 because a defect in ubcP1/ubc4+ cannot be suppressed by high expression of UbcP4/Ubc11 and a defect in ubcP4/ubc11+ cannot be suppressed by high expression of UbcP1/Ubc4. In vivo analysis of the ubiquitinated state of Cdc13 shows that the ubiquitin chains on Cdc13 were short in ubcP1/ubc4 mutant cells while ubiquitinated Cdc13 was totally reduced in ubcP4/ubc11 mutant cells. Taken together, these results indicate that the two ubiquitin-conjugating enzymes play distinct and essential roles in the degradation of mitotic cyclin Cdc13, with the UbcP4/Ubc11-pathway initiating ubiquitination of Cdc13 and the UbcP1/Ubc4-pathway elongating the short ubiquitin chains on Cdc13.
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Affiliation(s)
- Hiroaki Seino
- Division of Mutagenesis, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan.
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50
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Giordano TJ, Thomas DG, Kuick R, Lizyness M, Misek DE, Smith AL, Sanders D, Aljundi RT, Gauger PG, Thompson NW, Taylor JMG, Hanash SM. Distinct transcriptional profiles of adrenocortical tumors uncovered by DNA microarray analysis. THE AMERICAN JOURNAL OF PATHOLOGY 2003; 162:521-31. [PMID: 12547710 PMCID: PMC1851158 DOI: 10.1016/s0002-9440(10)63846-1] [Citation(s) in RCA: 235] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Comprehensive expression profiling of tumors using DNA microarrays has been used recently for molecular classification and biomarker discovery, as well as a tool to identify and investigate genes involved in tumorigenesis. Application of this approach to a cohort of benign and malignant adrenocortical tissues would be potentially informative in all of these aspects. In this study, we generated transcriptional profiles of 11 adrenocortical carcinomas (ACCs), 4 adrenocortical adenomas (ACAs), 3 normal adrenal cortices (NCs), and 1 macronodular hyperplasia (MNH) using Affymetrix HG_U95Av2 oligonucleotide arrays representing approximately 10,500 unique genes. The expression data set was used for unsupervised hierarchical cluster analysis as well as principal component analysis to visually represent the expression data. An analysis of variance on the three classes (NC, ACA plus MNH, and ACC) revealed 91 genes that displayed at least threefold differential expression between the ACC cohort and both the NC and ACA cohorts at a significance level of P < 0.01. Included in these 91 genes were those known to be up-regulated in adrenocortical tumors, such as insulin-like growth factor (IGF2), as well as novel differentially expressed genes such as osteopontin (SPP) and serine threonine kinase 15 (STK15). Increased expression of IGF2 was identified in 10 of 11 ACCs (90.9%) and was verified by quantitative reverse transcriptase-polymerase chain reaction. Select proliferation-related genes (TOP2A and Ki-67) were validated at the protein level using immunohistochemistry and adrenocortical tissue microarrays. Our results demonstrated significant and consistent gene expression changes in ACCs compared to benign adrenocortical lesions. Moreover, we identified several genes that represent potential diagnostic markers and may play a role in the pathogenesis of ACC.
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Affiliation(s)
- Thomas J Giordano
- Departments of Pathology, Pediatrics, Surgery, and Biostatistics, University of Michigan Health System, Ann Arbor, Michigan 48109-0054, USA.
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