1
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Mandal K, Tomar SK, Kumar Santra M. Decoding the ubiquitin language: Orchestrating transcription initiation and gene expression through chromatin remodelers and histones. Gene 2024; 904:148218. [PMID: 38307220 DOI: 10.1016/j.gene.2024.148218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 01/22/2024] [Accepted: 01/25/2024] [Indexed: 02/04/2024]
Abstract
Eukaryotic transcription is a finely orchestrated process and it is controlled by transcription factors as well as epigenetic regulators. Transcription factors and epigenetic regulators undergo different types of posttranslational modifications including ubiquitination to control transcription process. Ubiquitination, traditionally associated with protein degradation, has emerged as a crucial contributor to the regulation of chromatin structure through ubiquitination of histone and chromatin remodelers. Ubiquitination introduces new layers of intricacy to the regulation of transcription initiation through controlling the equilibrium between euchromatin and heterochromatin states. Nucleosome, the fundamental units of chromatin, spacing in euchromatin and heterochromatin states are regulated by histone modification and chromatin remodeling complexes. Chromatin remodeling complexes actively sculpt the chromatin architecture and thereby influence the transcriptional states of genes. Therefore, understanding the dynamic behavior of nucleosome spacing is critical as it impacts various cellular functions through controlling gene expression profiles. In this comprehensive review, we discussed the intricate interplay between ubiquitination and transcription initiation, and illuminated the underlying molecular mechanisms that occur in a variety of biological contexts. This exploration sheds light on the complex regulatory networks that govern eukaryotic transcription, providing important insights into the fine orchestration of gene expression and chromatin dynamics.
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Affiliation(s)
- Kartik Mandal
- Cancer Biology Division, National Centre for Cell Science, Ganeshkhind Road, Pune, Maharashtra 411007, India; Department of Biotechnology, Savitribai Phule Pune University, Ganeshkhind Road, Pune, Maharashtra 411007, India
| | - Shiva Kumar Tomar
- Cancer Biology Division, National Centre for Cell Science, Ganeshkhind Road, Pune, Maharashtra 411007, India; Department of Biotechnology, Savitribai Phule Pune University, Ganeshkhind Road, Pune, Maharashtra 411007, India
| | - Manas Kumar Santra
- Cancer Biology Division, National Centre for Cell Science, Ganeshkhind Road, Pune, Maharashtra 411007, India.
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2
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Zhou F, Deng Z, Shen D, Lu M, Li M, Yu J, Xiao Y, Wang G, Qian K, Ju L, Wang X. DLGAP5 triggers proliferation and metastasis of bladder cancer by stabilizing E2F1 via USP11. Oncogene 2024; 43:594-607. [PMID: 38182895 DOI: 10.1038/s41388-023-02932-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2023] [Revised: 12/15/2023] [Accepted: 12/21/2023] [Indexed: 01/07/2024]
Abstract
Bladder cancer (BLCA) is one of the most widespread malignancies worldwide, and displays significant tumor heterogeneity. Understanding the molecular mechanisms exploitable for treating aggressive BLCA represents a crucial objective. Despite the involvement of DLGAP5 in tumors, its precise molecular role in BLCA remains unclear. BLCA tissues exhibit a substantial increase in DLGAP5 expression compared with normal bladder tissues. This heightened DLGAP5 expression positively correlated with the tumor's clinical stage and significantly affected prognosis negatively. Additionally, experiments conducted in vitro and in vivo revealed that alterations in DLGAP5 expression notably influence cell proliferation and migration. Mechanistically, the findings demonstrated that DLGAP5 was a direct binding partner of E2F1 and that DLGAP5 stabilized E2F1 by preventing the ubiquitination of E2F1 through USP11. Furthermore, as a pivotal transcription factor, E2F1 fosters the transcription of DLGAP5, establishing a positive feedback loop between DLGAP5 and E2F1 that accelerates BLCA development. In summary, this study identified DLGAP5 as an oncogene in BLCA. Our research unveils a novel oncogenic mechanism in BLCA and offers a potential target for both diagnosing and treating BLCA.
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Affiliation(s)
- Fenfang Zhou
- Department of Urology, Laboratory of Precision Medicine, Zhongnan Hospital of Wuhan University, Wuhan, China
- Department of Radiology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Zhao Deng
- Department of Urology, Laboratory of Precision Medicine, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Dexin Shen
- Department of Urology, Laboratory of Precision Medicine, Zhongnan Hospital of Wuhan University, Wuhan, China
- Department of Urology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Mengxin Lu
- Department of Urology, Laboratory of Precision Medicine, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Mingxing Li
- Department of Urology, Laboratory of Precision Medicine, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Jingtian Yu
- Department of Urology, Laboratory of Precision Medicine, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Yu Xiao
- Department of Urology, Laboratory of Precision Medicine, Zhongnan Hospital of Wuhan University, Wuhan, China
- Department of Biological Repositories, Human Genetic Resources Preservation Center of Hubei Province, Hubei Key Laboratory of Urological Diseases, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Gang Wang
- Department of Biological Repositories, Human Genetic Resources Preservation Center of Hubei Province, Hubei Key Laboratory of Urological Diseases, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Kaiyu Qian
- Department of Biological Repositories, Human Genetic Resources Preservation Center of Hubei Province, Hubei Key Laboratory of Urological Diseases, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Lingao Ju
- Department of Biological Repositories, Human Genetic Resources Preservation Center of Hubei Province, Hubei Key Laboratory of Urological Diseases, Zhongnan Hospital of Wuhan University, Wuhan, China.
| | - Xinghuan Wang
- Department of Urology, Laboratory of Precision Medicine, Zhongnan Hospital of Wuhan University, Wuhan, China.
- Department of Biological Repositories, Human Genetic Resources Preservation Center of Hubei Province, Hubei Key Laboratory of Urological Diseases, Zhongnan Hospital of Wuhan University, Wuhan, China.
- Medical Research Institute, Frontier Science Center for Immunology and Metabolism, Taikang Center for Life and Medical Sciences, Wuhan University, Wuhan, China.
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3
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Koo SY, Park EJ, Noh HJ, Jo SM, Ko BK, Shin HJ, Lee CW. Ubiquitination Links DNA Damage and Repair Signaling to Cancer Metabolism. Int J Mol Sci 2023; 24:ijms24098441. [PMID: 37176148 PMCID: PMC10179089 DOI: 10.3390/ijms24098441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 05/04/2023] [Accepted: 05/05/2023] [Indexed: 05/15/2023] Open
Abstract
Changes in the DNA damage response (DDR) and cellular metabolism are two important factors that allow cancer cells to proliferate. DDR is a set of events in which DNA damage is recognized, DNA repair factors are recruited to the site of damage, the lesion is repaired, and cellular responses associated with the damage are processed. In cancer, DDR is commonly dysregulated, and the enzymes associated with DDR are prone to changes in ubiquitination. Additionally, cellular metabolism, especially glycolysis, is upregulated in cancer cells, and enzymes in this metabolic pathway are modulated by ubiquitination. The ubiquitin-proteasome system (UPS), particularly E3 ligases, act as a bridge between cellular metabolism and DDR since they regulate the enzymes associated with the two processes. Hence, the E3 ligases with high substrate specificity are considered potential therapeutic targets for treating cancer. A number of small molecule inhibitors designed to target different components of the UPS have been developed, and several have been tested in clinical trials for human use. In this review, we discuss the role of ubiquitination on overall cellular metabolism and DDR and confirm the link between them through the E3 ligases NEDD4, APC/CCDH1, FBXW7, and Pellino1. In addition, we present an overview of the clinically important small molecule inhibitors and implications for their practical use.
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Affiliation(s)
- Seo-Young Koo
- Department of Molecular Cell Biology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Suwon 16419, Republic of Korea
| | - Eun-Ji Park
- Department of Molecular Cell Biology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Suwon 16419, Republic of Korea
| | - Hyun-Ji Noh
- Department of Molecular Cell Biology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Suwon 16419, Republic of Korea
| | - Su-Mi Jo
- Department of Molecular Cell Biology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Suwon 16419, Republic of Korea
| | - Bo-Kyoung Ko
- Department of Molecular Cell Biology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Suwon 16419, Republic of Korea
| | - Hyun-Jin Shin
- Team of Radiation Convergence Research, Korea Institute of Radiological & Medical Sciences, Seoul 01812, Republic of Korea
| | - Chang-Woo Lee
- Department of Molecular Cell Biology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Suwon 16419, Republic of Korea
- SKKU Institute for Convergence, Sungkyunkwan University, Suwon 16419, Republic of Korea
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4
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Chen S, He Z, Peng T, Zhou F, Wang G, Qian K, Ju L, Xiao Y, Wang X. PRR11 promotes ccRCC tumorigenesis by regulating E2F1 stability. JCI Insight 2021; 6:e145172. [PMID: 34499617 PMCID: PMC8525590 DOI: 10.1172/jci.insight.145172] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 09/01/2021] [Indexed: 01/03/2023] Open
Abstract
Proline rich 11 (PRR11), a novel tumor-related gene, has been identified in different tumors. However, the relevant biological functions of PRR11 in human clear cell renal cell carcinoma (ccRCC) have not been studied. In this study, we first identified PRR11 as a biomarker of ccRCC and predictor of poor prognosis by bioinformatics. Then, we showed that PRR11 silencing substantially reduced ccRCC cell proliferation and migration in vitro and in vivo. Importantly, we found that PRR11 induced the degradation of the E2F1 protein through its interaction with E2F1, and PRR11 reduced the stability of the E2F1 protein in ccRCC cells, thereby affecting cell cycle progression. Further results indicated that the downregulation of E2F1 expression partially reversed the changes in ccRCC cell biology caused by PRR11 deletion. In addition, we showed that PRR11 was a target gene of c-Myc. The transcription factor c-Myc may have promoted the expression of PRR11 in ccRCC cells by binding to the PRR11 promoter region, thereby accelerating the progression of ccRCC. In summary, we found that PRR11 served as an oncogene in ccRCC, and PRR11 reduced the protein stability of E2F1 and could be activated by c-Myc.
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Affiliation(s)
| | | | | | | | - Gang Wang
- Department of Biological Repositories, Zhongnan Hospital of Wuhan University, Wuhan, China.,Human Genetic Resource Preservation Center of Hubei Province, Wuhan, China.,Research Center of Wuhan for Infectious Diseases and Cancer, Chinese Academy of Medical Sciences, Wuhan, China.,Laboratory of Precision Medicine, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Kaiyu Qian
- Department of Biological Repositories, Zhongnan Hospital of Wuhan University, Wuhan, China.,Human Genetic Resource Preservation Center of Hubei Province, Wuhan, China.,Research Center of Wuhan for Infectious Diseases and Cancer, Chinese Academy of Medical Sciences, Wuhan, China.,Laboratory of Precision Medicine, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Lingao Ju
- Department of Biological Repositories, Zhongnan Hospital of Wuhan University, Wuhan, China.,Human Genetic Resource Preservation Center of Hubei Province, Wuhan, China.,Research Center of Wuhan for Infectious Diseases and Cancer, Chinese Academy of Medical Sciences, Wuhan, China.,Laboratory of Precision Medicine, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Yu Xiao
- Department of Urology and.,Department of Biological Repositories, Zhongnan Hospital of Wuhan University, Wuhan, China.,Human Genetic Resource Preservation Center of Hubei Province, Wuhan, China.,Research Center of Wuhan for Infectious Diseases and Cancer, Chinese Academy of Medical Sciences, Wuhan, China.,Laboratory of Precision Medicine, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Xinghuan Wang
- Department of Urology and.,Research Center of Wuhan for Infectious Diseases and Cancer, Chinese Academy of Medical Sciences, Wuhan, China.,Medical Research Institute, Wuhan University, Wuhan, China
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5
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Allmann S, Mayer L, Olma J, Kaina B, Hofmann TG, Tomicic MT, Christmann M. Benzo[a]pyrene represses DNA repair through altered E2F1/E2F4 function marking an early event in DNA damage-induced cellular senescence. Nucleic Acids Res 2020; 48:12085-12101. [PMID: 33166399 PMCID: PMC7708059 DOI: 10.1093/nar/gkaa965] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 09/25/2020] [Accepted: 10/16/2020] [Indexed: 01/08/2023] Open
Abstract
Transcriptional regulation of DNA repair is of outmost importance for the restoration of DNA integrity upon genotoxic stress. Here we report that the potent environmental carcinogen benzo[a]pyrene (B[a]P) activates a cellular DNA damage response resulting in transcriptional repression of mismatch repair (MMR) genes (MSH2, MSH6, EXO1) and of RAD51, the central homologous recombination repair (HR) component, ultimately leading to downregulation of MMR and HR. B[a]P-induced gene repression is caused by abrogated E2F1 signalling. This occurs through proteasomal degradation of E2F1 in G2-arrested cells and downregulation of E2F1 mRNA expression in G1-arrested cells. Repression of E2F1-mediated transcription and silencing of repair genes is further mediated by the p21-dependent E2F4/DREAM complex. Notably, repression of DNA repair is also observed following exposure to the active B[a]P metabolite BPDE and upon ionizing radiation and occurs in response to a p53/p21-triggered, irreversible cell cycle arrest marking the onset of cellular senescence. Overall, our results suggest that repression of MMR and HR is an early event during genotoxic-stress induced senescence. We propose that persistent downregulation of DNA repair might play a role in the maintenance of the senescence phenotype, which is associated with an accumulation of unrepairable DNA lesions.
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Affiliation(s)
- Sebastian Allmann
- Institute of Toxicology, University Medical Center, Johannes Gutenberg University of Mainz, Obere Zahlbacher Str. 67, D-55131 Mainz, Germany
| | - Laura Mayer
- Institute of Toxicology, University Medical Center, Johannes Gutenberg University of Mainz, Obere Zahlbacher Str. 67, D-55131 Mainz, Germany
| | - Jessika Olma
- Institute of Toxicology, University Medical Center, Johannes Gutenberg University of Mainz, Obere Zahlbacher Str. 67, D-55131 Mainz, Germany
| | - Bernd Kaina
- Institute of Toxicology, University Medical Center, Johannes Gutenberg University of Mainz, Obere Zahlbacher Str. 67, D-55131 Mainz, Germany
| | - Thomas G Hofmann
- Institute of Toxicology, University Medical Center, Johannes Gutenberg University of Mainz, Obere Zahlbacher Str. 67, D-55131 Mainz, Germany
| | - Maja T Tomicic
- Institute of Toxicology, University Medical Center, Johannes Gutenberg University of Mainz, Obere Zahlbacher Str. 67, D-55131 Mainz, Germany
| | - Markus Christmann
- Institute of Toxicology, University Medical Center, Johannes Gutenberg University of Mainz, Obere Zahlbacher Str. 67, D-55131 Mainz, Germany
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6
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Quantifying the Landscape and Transition Paths for Proliferation-Quiescence Fate Decisions. J Clin Med 2020; 9:jcm9082582. [PMID: 32784979 PMCID: PMC7466041 DOI: 10.3390/jcm9082582] [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: 07/04/2020] [Revised: 07/30/2020] [Accepted: 08/03/2020] [Indexed: 12/01/2022] Open
Abstract
The cell cycle, essential for biological functions, experiences delicate spatiotemporal regulation. The transition between G1 and S phase, which is called the proliferation–quiescence decision, is critical to the cell cycle. However, the stability and underlying stochastic dynamical mechanisms of the proliferation–quiescence decision have not been fully understood. To quantify the process of the proliferation–quiescence decision, we constructed its underlying landscape based on the relevant gene regulatory network. We identified three attractors on the landscape corresponding to the G0, G1, and S phases, individually, which are supported by single-cell data. By calculating the transition path, which quantifies the potential barrier, we built expression profiles in temporal order for key regulators in different transitions. We propose that the two saddle points on the landscape characterize restriction point (RP) and G1/S checkpoint, respectively, which provides quantitative and physical explanations for the mechanisms of Rb governing the RP while p21 controlling the G1/S checkpoint. We found that Emi1 inhibits the transition from G0 to G1, while Emi1 in a suitable range facilitates the transition from G1 to S. These results are partially consistent with previous studies, which also suggested new roles of Emi1 in the cell cycle. By global sensitivity analysis, we identified some critical regulatory factors influencing the proliferation–quiescence decision. Our work provides a global view of the stochasticity and dynamics in the proliferation–quiescence decision of the cell cycle.
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7
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Emanuele MJ, Enrico TP, Mouery RD, Wasserman D, Nachum S, Tzur A. Complex Cartography: Regulation of E2F Transcription Factors by Cyclin F and Ubiquitin. Trends Cell Biol 2020; 30:640-652. [PMID: 32513610 PMCID: PMC7859860 DOI: 10.1016/j.tcb.2020.05.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 05/01/2020] [Accepted: 05/06/2020] [Indexed: 02/07/2023]
Abstract
The E2F family of transcriptional regulators sits at the center of cell cycle gene expression and plays vital roles in normal and cancer cell cycles. Whereas control of E2Fs by the retinoblastoma family of proteins is well established, much less is known about their regulation by ubiquitin pathways. Recent studies placed the Skp1-Cul1-F-box-protein (SCF) family of E3 ubiquitin ligases with the F-box protein Cyclin F at the center of E2F regulation, demonstrating temporal proteolysis of both activator and atypical repressor E2Fs. Importantly, these E2F members, in particular activator E2F1 and repressors E2F7 and E2F8, form a feedback circuit at the crossroads of cell cycle and cell death. Moreover, Cyclin F functions in a reciprocal circuit with the cell cycle E3 ligase anaphase-promoting complex/cyclosome (APC/C), which also controls E2F7 and E2F8. This review focuses on the complex contours of feedback within this circuit, highlighting the deep crosstalk between E2F, SCF-Cyclin F, and APC/C in regulating the oscillator underlying human cell cycles.
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Affiliation(s)
- Michael J Emanuele
- Department of Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
| | - Taylor P Enrico
- Department of Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Ryan D Mouery
- Department of Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Genetics and Molecular Biology Program, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Danit Wasserman
- Faculty of Life Sciences and Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Sapir Nachum
- Faculty of Life Sciences and Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Amit Tzur
- Faculty of Life Sciences and Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 5290002, Israel.
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8
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Valdez-Sinon AN, Lai A, Shi L, Lancaster CL, Gokhale A, Faundez V, Bassell GJ. Cdh1-APC Regulates Protein Synthesis and Stress Granules in Neurons through an FMRP-Dependent Mechanism. iScience 2020; 23:101132. [PMID: 32434143 PMCID: PMC7236060 DOI: 10.1016/j.isci.2020.101132] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 01/22/2020] [Accepted: 04/28/2020] [Indexed: 12/14/2022] Open
Abstract
Maintaining a balance between protein degradation and protein synthesis is necessary for neurodevelopment. Although the E3 ubiquitin ligase anaphase promoting complex and its regulatory subunit Cdh1 (Cdh1-APC) has been shown to regulate learning and memory, the underlying mechanisms are unclear. Here, we have identified a role of Cdh1-APC as a regulator of protein synthesis in neurons. Proteomic profiling revealed that Cdh1-APC interacts with known regulators of translation, including stress granule proteins. Inhibition of Cdh1-APC activity caused an increase in stress granule formation that is dependent on fragile X mental retardation protein (FMRP). We propose a model in which Cdh1-APC targets stress granule proteins, such as FMRP, and inhibits the formation of stress granules, leading to protein synthesis. Elucidation of a role for Cdh1-APC in regulation of stress granules and protein synthesis in neurons has implications for how Cdh1-APC can regulate protein-synthesis-dependent synaptic plasticity underlying learning and memory.
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Affiliation(s)
| | - Austin Lai
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Liang Shi
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Carly L. Lancaster
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Avanti Gokhale
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Victor Faundez
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Gary J. Bassell
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA,Corresponding author
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9
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Chan AB, Huber AL, Lamia KA. Cryptochromes modulate E2F family transcription factors. Sci Rep 2020; 10:4077. [PMID: 32139766 PMCID: PMC7058038 DOI: 10.1038/s41598-020-61087-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 02/12/2020] [Indexed: 12/27/2022] Open
Abstract
Early 2 factor (E2F) family transcription factors participate in myriad cell biological processes including: the cell cycle, DNA repair, apoptosis, development, differentiation, and metabolism. Circadian rhythms influence many of these phenomena. Here we find that a mammalian circadian rhythm component, Cryptochrome 2 (CRY2), regulates E2F family members. Furthermore, CRY1 and CRY2 cooperate with the E3 ligase complex SKP-CULLIN-FBXL3 (SCFFBXL3) to reduce E2F steady state protein levels. These findings reveal an unrecognized molecular connection between circadian clocks and cell cycle regulation and highlight another mechanism to maintain appropriate E2F protein levels for proper cell growth.
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Affiliation(s)
- Alanna B Chan
- Department of Molecular Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Anne-Laure Huber
- Department of Molecular Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
- Centre de Recherche en Cancerologie de Lyon, 28 rue Laennec, 69008, Lyon, France
| | - Katja A Lamia
- Department of Molecular Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA.
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10
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Wasserman D, Nachum S, Cohen M, Enrico TP, Noach-Hirsh M, Parasol J, Zomer-Polak S, Auerbach N, Sheinberger-Chorni E, Nevenzal H, Levi-Dadon N, Wang X, Lahmi R, Michaely E, Gerber D, Emanuele MJ, Tzur A. Cell cycle oscillators underlying orderly proteolysis of E2F8. Mol Biol Cell 2020; 31:725-740. [PMID: 31995441 PMCID: PMC7185961 DOI: 10.1091/mbc.e19-12-0725] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
E2F8 is a transcriptional repressor that antagonizes E2F1 at the crossroads of the cell cycle, apoptosis, and cancer. Previously, we discovered that E2F8 is a direct target of the APC/C ubiquitin ligase. Nevertheless, it remains unknown how E2F8 is dynamically controlled throughout the entirety of the cell cycle. Here, using newly developed human cell-free systems that recapitulate distinct inter-mitotic and G1 phases and a continuous transition from prometaphase to G1, we reveal an interlocking dephosphorylation switch coordinating E2F8 degradation with mitotic exit and the activation of APC/CCdh1. Further, we uncover differential proteolysis rates for E2F8 at different points within G1 phase, accounting for its accumulation in late G1 while APC/CCdh1 is still active. Finally, we demonstrate that the F-box protein Cyclin F regulates E2F8 in G2-phase. Altogether, our data define E2F8 regulation throughout the cell cycle, illuminating an extensive coordination between phosphorylation, ubiquitination and transcription in mammalian cell cycle.
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Affiliation(s)
- Danit Wasserman
- Faculty of Life Sciences and Institute of Nanotechnology and Advanced Materials, Bar-llan University, Ramat-Gan 5290002, Israel
| | - Sapir Nachum
- Faculty of Life Sciences and Institute of Nanotechnology and Advanced Materials, Bar-llan University, Ramat-Gan 5290002, Israel
| | - Meital Cohen
- Faculty of Life Sciences and Institute of Nanotechnology and Advanced Materials, Bar-llan University, Ramat-Gan 5290002, Israel
| | - Taylor P Enrico
- Department of Pharmacology, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Meirav Noach-Hirsh
- Faculty of Life Sciences and Institute of Nanotechnology and Advanced Materials, Bar-llan University, Ramat-Gan 5290002, Israel
| | - Jasmin Parasol
- Faculty of Life Sciences and Institute of Nanotechnology and Advanced Materials, Bar-llan University, Ramat-Gan 5290002, Israel
| | - Sarit Zomer-Polak
- Faculty of Life Sciences and Institute of Nanotechnology and Advanced Materials, Bar-llan University, Ramat-Gan 5290002, Israel
| | - Naomi Auerbach
- Faculty of Life Sciences and Institute of Nanotechnology and Advanced Materials, Bar-llan University, Ramat-Gan 5290002, Israel
| | - Evelin Sheinberger-Chorni
- Faculty of Life Sciences and Institute of Nanotechnology and Advanced Materials, Bar-llan University, Ramat-Gan 5290002, Israel
| | - Hadas Nevenzal
- Faculty of Life Sciences and Institute of Nanotechnology and Advanced Materials, Bar-llan University, Ramat-Gan 5290002, Israel
| | - Nofar Levi-Dadon
- Faculty of Life Sciences and Institute of Nanotechnology and Advanced Materials, Bar-llan University, Ramat-Gan 5290002, Israel
| | - Xianxi Wang
- Department of Pharmacology, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Roxane Lahmi
- Faculty of Life Sciences and Institute of Nanotechnology and Advanced Materials, Bar-llan University, Ramat-Gan 5290002, Israel
| | - Efrat Michaely
- Faculty of Life Sciences and Institute of Nanotechnology and Advanced Materials, Bar-llan University, Ramat-Gan 5290002, Israel
| | - Doron Gerber
- Faculty of Life Sciences and Institute of Nanotechnology and Advanced Materials, Bar-llan University, Ramat-Gan 5290002, Israel
| | - Michael J Emanuele
- Department of Pharmacology, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Amit Tzur
- Faculty of Life Sciences and Institute of Nanotechnology and Advanced Materials, Bar-llan University, Ramat-Gan 5290002, Israel
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11
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Burdova K, Yang H, Faedda R, Hume S, Chauhan J, Ebner D, Kessler BM, Vendrell I, Drewry DH, Wells CI, Hatch SB, Dianov GL, Buffa FM, D'Angiolella V. E2F1 proteolysis via SCF-cyclin F underlies synthetic lethality between cyclin F loss and Chk1 inhibition. EMBO J 2019; 38:e101443. [PMID: 31424118 PMCID: PMC6792013 DOI: 10.15252/embj.2018101443] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2019] [Revised: 07/05/2019] [Accepted: 07/29/2019] [Indexed: 12/27/2022] Open
Abstract
Cyclins are central engines of cell cycle progression in conjunction with cyclin-dependent kinases (CDKs). Among the different cyclins controlling cell cycle progression, cyclin F does not partner with a CDK, but instead forms via its F-box domain an SCF (Skp1-Cul1-F-box)-type E3 ubiquitin ligase module. Although various substrates of cyclin F have been identified, the vulnerabilities of cells lacking cyclin F are not known. Thus, we assessed viability of cells lacking cyclin F upon challenging them with more than 180 different kinase inhibitors. The screen revealed a striking synthetic lethality between Chk1 inhibition and cyclin F loss. Chk1 inhibition in cells lacking cyclin F leads to DNA replication catastrophe. Replication catastrophe depends on accumulation of the transcription factor E2F1 in cyclin F-depleted cells. We find that SCF-cyclin F controls E2F1 ubiquitylation and degradation during the G2/M phase of the cell cycle and upon challenging cells with Chk1 inhibitors. Thus, Cyclin F restricts E2F1 activity during the cell cycle and upon checkpoint inhibition to prevent DNA replication stress. Our findings pave the way for patient selection in the clinical use of checkpoint inhibitors.
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Affiliation(s)
- Kamila Burdova
- Department of OncologyMedical Research Council Institute for Radiation OncologyUniversity of OxfordOxfordUK
| | - Hongbin Yang
- Department of OncologyMedical Research Council Institute for Radiation OncologyUniversity of OxfordOxfordUK
| | - Roberta Faedda
- Department of OncologyMedical Research Council Institute for Radiation OncologyUniversity of OxfordOxfordUK
| | - Samuel Hume
- Department of OncologyMedical Research Council Institute for Radiation OncologyUniversity of OxfordOxfordUK
| | - Jagat Chauhan
- Nuffield Department of Clinical MedicineLudwig Institute for Cancer ResearchUniversity of OxfordHeadington, OxfordUK
| | - Daniel Ebner
- Nuffield Department of MedicineTarget Discovery InstituteUniversity of OxfordOxfordUK
| | - Benedikt M Kessler
- Nuffield Department of MedicineTarget Discovery InstituteUniversity of OxfordOxfordUK
| | - Iolanda Vendrell
- Department of OncologyMedical Research Council Institute for Radiation OncologyUniversity of OxfordOxfordUK
- Nuffield Department of MedicineTarget Discovery InstituteUniversity of OxfordOxfordUK
| | - David H Drewry
- Structural Genomics ConsortiumUNC Eshelman School of PharmacyUniversity of North Carolina at Chapel HillChapel HillNCUSA
| | - Carrow I Wells
- Structural Genomics ConsortiumUNC Eshelman School of PharmacyUniversity of North Carolina at Chapel HillChapel HillNCUSA
| | - Stephanie B Hatch
- Nuffield Department of MedicineTarget Discovery InstituteUniversity of OxfordOxfordUK
| | - Grigory L Dianov
- Department of OncologyMedical Research Council Institute for Radiation OncologyUniversity of OxfordOxfordUK
- Institute of Cytology and GeneticsRussian Academy of SciencesNovosibirskRussian Federation
- Novosibirsk State UniversityNovosibirskRussian Federation
| | - Francesca M Buffa
- Department of OncologyMedical Research Council Institute for Radiation OncologyUniversity of OxfordOxfordUK
| | - Vincenzo D'Angiolella
- Department of OncologyMedical Research Council Institute for Radiation OncologyUniversity of OxfordOxfordUK
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12
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Wang D, Zhao J, Li S, Wei J, Nan L, Mallampalli RK, Weathington NM, Ma H, Zhao Y. Phosphorylated E2F1 is stabilized by nuclear USP11 to drive Peg10 gene expression and activate lung epithelial cells. J Mol Cell Biol 2019; 10:60-73. [PMID: 28992046 DOI: 10.1093/jmcb/mjx034] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 08/15/2017] [Indexed: 12/21/2022] Open
Abstract
Phosphorylation affects ubiquitination, stability, and activity of transcriptional factors, thus regulating various cellular functions. E2F transcriptional factor 1 (E2F1) regulates paternally expressed imprinted gene 10 (Peg10) expression, thereby promoting cell proliferation. However, the effect of E2F1 stability on Peg10 expression and the molecular regulation of E2F1 stability by its phosphorylation have not been well demonstrated. Here, we describe a new pathway in which phosphorylation of E2F1 by GSK3β increases E2F1 association with the deubiquitinating enzyme, ubiquitin-specific protease 11 (USP11), which removes K63-linked ubiquitin chains thereby preventing E2F1 degradation in the nuclei. Downregulation of USP11 increases E2F1 ubiquitination and reduces E2F1 stability and protein levels, thereby decreasing Peg10 mRNA levels. Physiologically, USP11 depletion suppresses cell proliferation and wound healing in lung epithelial cells, and these effects are reversed by E2F1 and PEG10 overexpression. Thus, our study reveals a new molecular model that phosphorylation promotes substrate stability through increasing its association with a deubiquitinating enzyme. The data suggest that GSK3β and USP11 act in concert to modulate E2F1 abundance and PEG10 expression in lung epithelial cells to affect cell wound healing. This study provides new therapeutic targets to lessen lung injury by improving lung epithelial cell repair and remodeling after injury.
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Affiliation(s)
- Dan Wang
- Department of Anesthesia, the First Affiliated Hospital of Jilin University, Changchun, China
| | - Jing Zhao
- Department of Medicine, Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh, Pittsburgh, USA
| | - Shuang Li
- Department of Medicine, Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh, Pittsburgh, USA.,Department of General Surgery, the First Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Jianxin Wei
- Department of Medicine, Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh, Pittsburgh, USA
| | - Ling Nan
- Department of Anesthesia, the First Affiliated Hospital of Jilin University, Changchun, China
| | - Rama K Mallampalli
- Department of Medicine, Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh, Pittsburgh, USA.,Acute Lung Injury Center of Excellence and Vascular Medical Institute, University of Pittsburgh, Pittsburgh, USA
| | - Nathaniel M Weathington
- Department of Medicine, Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh, Pittsburgh, USA.,Acute Lung Injury Center of Excellence and Vascular Medical Institute, University of Pittsburgh, Pittsburgh, USA
| | - Haichun Ma
- Department of Anesthesia, the First Affiliated Hospital of Jilin University, Changchun, China
| | - Yutong Zhao
- Department of Medicine, Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh, Pittsburgh, USA.,Acute Lung Injury Center of Excellence and Vascular Medical Institute, University of Pittsburgh, Pittsburgh, USA
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13
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Abstract
The cyclin-dependent kinase (CDK)-RB-E2F axis forms the core transcriptional machinery driving cell cycle progression, dictating the timing and fidelity of genome replication and ensuring genetic material is accurately passed through each cell division cycle. The ultimate effectors of this axis are members of a family of eight distinct E2F genes encoding transcriptional activators and repressors. E2F transcriptional activity is tightly regulated throughout the cell cycle via transcriptional and translational regulation, post-translational modifications, protein degradation, binding to cofactors and subcellular localization. Alterations in one or more key components of this axis (CDKs, cyclins, CDK inhibitors and the RB family of proteins) occur in virtually all cancers and result in heightened oncogenic E2F activity, leading to uncontrolled proliferation. In this Review, we discuss the activities of E2F proteins with an emphasis on the newest atypical E2F family members, the specific and redundant functions of E2F proteins, how misexpression of E2F transcriptional targets promotes cancer and both current and developing therapeutic strategies being used to target this oncogenic pathway.
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Affiliation(s)
- Lindsey N Kent
- Department of Biochemistry and Molecular Biology, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, USA
| | - Gustavo Leone
- Department of Biochemistry and Molecular Biology, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, USA.
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14
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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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15
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Perla V, Nadimi M, Reddy R, Hankins GR, Nimmakayala P, Harris RT, Valluri J, Sirbu C, Reddy UK. Effect of ghost pepper on cell proliferation, apoptosis, senescence and global proteomic profile in human renal adenocarcinoma cells. PLoS One 2018; 13:e0206183. [PMID: 30379886 PMCID: PMC6209291 DOI: 10.1371/journal.pone.0206183] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 10/07/2018] [Indexed: 12/19/2022] Open
Abstract
Chili peppers are an important constituent of many foods and contain medicinally valuable compounds, such as capsaicin and dihydrocapsaicin. As various dietary botanicals have anticancer properties, this study was aimed to examine the effect of Ghost pepper (Bhut Jolokia), one of the hottest chili peppers in the world, on cell proliferation, apoptosis, senescence and the global proteomic profile in human renal cell adenocarcinoma in vitro. 769-P human renal adenocarcinoma cells were cultured on RPMI-1640 media supplemented with fetal bovine serum (10%) and antibiotic-antimycotic solution (1%). Treatment stock solutions were prepared in ethanol. Cell proliferation was tested with phenol red-free media with capsaicin (0-400 μM), dihydrocapsaicin (0-400 μM), capsaicin + dihydrocapsaicin (5:1), and dry Ghost peppers (0-3 g L-1) for 24, 48 and 72 h. Polycaspase and senescence associated-beta-galactosidase (SA-beta-gal) activities were tested with capsaicin (400 μM), dihydrocapsaicin (400 μM), capsaicin (400 μM) + dihydrocapsaicin (80 μM), and ghost pepper (3 g L-1) treatments. Global proteomic profile of cells in control and ghost pepper treatment (3 g L-1) was analyzed after 6 h by a shotgun proteomic approach using tandem mass spectrometry. At 24 h after treatment (24 HAT), relative to control, cell proportion with capsaicin (400 μM), dihydrocapsaicin (400 μM), capsaicin (400 μM) + dihydrocapsaicin (80 μM), and ghost pepper (3 g L-1) treatments was reduced to 36%, 18%, 33% and 20%, respectively, and further reduced at 48 and 72 HAT. All treatments triggered an early polycaspase response. SA-beta-gal activity was normal or suppressed with all treatments. About 68,220 protein isoforms were identified by shotgun proteomic approach. Among these, about 8.2% were significantly affected by ghost pepper. Ghost pepper regulated various proteins involved in intrinsic and extrinsic apoptotic pathways, Ras, Rb/E2F, p53, TGF-beta, WNT-beta catenin, and calcium induced cell death pathways. Ghost pepper also induced changes in proteins related to methylation, acetylation, genome stability, cell cycle check points, carbohydrate, protein and other metabolism and cellular mechanisms. Ghost pepper exhibited antiproliferation activity by inducing apoptosis through a complex network of proteins in human renal cell adenocarcinoma in vitro.
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Affiliation(s)
- Venu Perla
- Gus R. Douglass Land-Grant Institute and Department of Biology, West Virginia State University, Institute, West Virginia, United States of America
| | - Marjan Nadimi
- Gus R. Douglass Land-Grant Institute and Department of Biology, West Virginia State University, Institute, West Virginia, United States of America
| | - Rishi Reddy
- Gus R. Douglass Land-Grant Institute and Department of Biology, West Virginia State University, Institute, West Virginia, United States of America
| | - Gerald R. Hankins
- Gus R. Douglass Land-Grant Institute and Department of Biology, West Virginia State University, Institute, West Virginia, United States of America
| | - Padma Nimmakayala
- Gus R. Douglass Land-Grant Institute and Department of Biology, West Virginia State University, Institute, West Virginia, United States of America
| | - Robert T. Harris
- Gus R. Douglass Land-Grant Institute and Department of Biology, West Virginia State University, Institute, West Virginia, United States of America
| | - Jagan Valluri
- Department of Biological Sciences, One John Marshall Drive, Marshall University, Huntington, West Virginia, United States of America
| | - Cristian Sirbu
- Center for Cancer Research, Charleston Area Medical Center, SE, Charleston, West Virginia, United States of America
| | - Umesh K. Reddy
- Gus R. Douglass Land-Grant Institute and Department of Biology, West Virginia State University, Institute, West Virginia, United States of America
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16
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Allègre J, Cartier J, Glorian V, Droin N, Dumetier B, Kayaci C, Berthelet J, Gemble S, Vuillier C, Maillet L, Garrido C, Dubrez L. E2F1 binds to the peptide-binding groove within the BIR3 domain of cIAP1 and requires cIAP1 for chromatin binding. PLoS One 2018; 13:e0206253. [PMID: 30359437 PMCID: PMC6201919 DOI: 10.1371/journal.pone.0206253] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 10/09/2018] [Indexed: 11/18/2022] Open
Abstract
The cellular inhibitor of apoptosis 1 (cIAP1) is an E3-ubiquitin ligase that regulates cell signaling pathways involved in fundamental cellular processes including cell death, cell proliferation, cell differentiation and inflammation. It recruits ubiquitination substrates thanks to the presence of three baculoviral IAP repeat (BIR) domains at its N-terminal extremity. We previously demonstrated that cIAP1 promoted the ubiquitination of the E2 factor 1 (E2F1) transcription factor. Moreover, we showed that cIAP1 was required for E2F1 stabilization during the S phase of cell cycle and in response to DNA damage. Here, we report that E2F1 binds within the cIAP1 BIR3 domain. The BIR3 contains a surface hydrophobic groove that specifically anchors a conserved IAP binding motif (IBM) found in a number of intracellular proteins including Smac. The Smac N-7 peptide that includes the IBM, as well as a Smac mimetic, competed with E2F1 for interaction with cIAP1 demonstrating the importance of the BIR surface hydrophobic groove. We demonstrated that the first alpha-helix of BIR3 was required for E2F1 binding, as well as for the binding of Smac and Smac mimetics. Overexpression of cIAP1 modified the ubiquitination profile of E2F1, increasing the ratio of E2F1 conjugated with K11- and K63-linked ubiquitin chains, and decreasing the proportion of E2F1 modified by K48-linked ubiquitin chains. ChIP-seq analysis demonstrated that cIAP1 was required for the recruitment of E2F1 onto chromatin. Lastly, we identified an E2F-binding site on the cIAP1-encoding birc2 gene promoter, suggesting a retro-control regulation loop.
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Affiliation(s)
- Jennifer Allègre
- Institut National de la Santé et de la Recherche Médicale (Inserm), LNC UMR1231, Dijon, France
- Université de Bourgogne Franche-Comté, LNC UMR1231, Dijon, France
| | - Jessy Cartier
- Institut National de la Santé et de la Recherche Médicale (Inserm), LNC UMR1231, Dijon, France
- Université de Bourgogne Franche-Comté, LNC UMR1231, Dijon, France
| | - Valérie Glorian
- Institut National de la Santé et de la Recherche Médicale (Inserm), LNC UMR1231, Dijon, France
- Université de Bourgogne Franche-Comté, LNC UMR1231, Dijon, France
| | | | - Baptiste Dumetier
- Institut National de la Santé et de la Recherche Médicale (Inserm), LNC UMR1231, Dijon, France
- Université de Bourgogne Franche-Comté, LNC UMR1231, Dijon, France
| | - Cémile Kayaci
- Institut National de la Santé et de la Recherche Médicale (Inserm), LNC UMR1231, Dijon, France
- Université de Bourgogne Franche-Comté, LNC UMR1231, Dijon, France
| | - Jean Berthelet
- Institut National de la Santé et de la Recherche Médicale (Inserm), LNC UMR1231, Dijon, France
- Université de Bourgogne Franche-Comté, LNC UMR1231, Dijon, France
| | - Simon Gemble
- Institut National de la Santé et de la Recherche Médicale (Inserm), LNC UMR1231, Dijon, France
- Université de Bourgogne Franche-Comté, LNC UMR1231, Dijon, France
| | | | | | - Carmen Garrido
- Institut National de la Santé et de la Recherche Médicale (Inserm), LNC UMR1231, Dijon, France
- Université de Bourgogne Franche-Comté, LNC UMR1231, Dijon, France
| | - Laurence Dubrez
- Institut National de la Santé et de la Recherche Médicale (Inserm), LNC UMR1231, Dijon, France
- Université de Bourgogne Franche-Comté, LNC UMR1231, Dijon, France
- * E-mail:
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17
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Singh RK, Dagnino L. CDH1 regulates E2F1 degradation in response to differentiation signals in keratinocytes. Oncotarget 2018; 8:4977-4993. [PMID: 27903963 PMCID: PMC5354885 DOI: 10.18632/oncotarget.13636] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 11/08/2016] [Indexed: 11/25/2022] Open
Abstract
The E2F1 transcription factor plays key roles in skin homeostasis. In the epidermis, E2F1 expression is essential for normal proliferation of undifferentiated keratinocytes, regeneration after injury and DNA repair following UV radiation-induced photodamage. Abnormal E2F1 expression promotes nonmelanoma skin carcinoma. In addition, E2F1 must be downregulated for proper keratinocyte differentiation, but the relevant mechanisms involved remain poorly understood. We show that differentiation signals induce a series of post-translational modifications in E2F1 that are jointly required for its downregulation. Analysis of the structural determinants that govern these processes revealed a central role for S403 and T433. In particular, substitution of these two amino acid residues with non-phosphorylatable alanine (E2F1 ST/A) interferes with E2F1 nuclear export, K11- and K48-linked polyubiquitylation and degradation in differentiated keratinocytes. In contrast, replacement of S403 and T433 with phosphomimetic aspartic acid to generate a pseudophosphorylated E2F1 mutant protein (E2F1 ST/D) generates a protein that is regulated in a manner indistinguishable from that of wild type E2F1. Cdh1 is an activating cofactor that interacts with the anaphase-promoting complex/cyclosome (APC/C) ubiquitin E3 ligase, promoting proteasomal degradation of various substrates. We found that Cdh1 associates with E2F1 in keratinocytes. Inhibition or RNAi-mediated silencing of Cdh1 prevents E2F1 degradation in response to differentiation signals. Our results reveal novel regulatory mechanisms that jointly modulate post-translational modifications and downregulation of E2F1, which are necessary for proper epidermal keratinocyte differentiation.
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Affiliation(s)
- Randeep K Singh
- Department of Physiology and Pharmacology, Children's Health Research Institute and Lawson Health Research Institute, The University of Western Ontario, London, Ontario N6A 5C1, Canada
| | - Lina Dagnino
- Department of Physiology and Pharmacology, Children's Health Research Institute and Lawson Health Research Institute, The University of Western Ontario, London, Ontario N6A 5C1, Canada
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18
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Dubrez L. Regulation of E2F1 Transcription Factor by Ubiquitin Conjugation. Int J Mol Sci 2017; 18:ijms18102188. [PMID: 29048367 PMCID: PMC5666869 DOI: 10.3390/ijms18102188] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 10/11/2017] [Accepted: 10/16/2017] [Indexed: 12/21/2022] Open
Abstract
Ubiquitination is a post-translational modification that defines the cellular fate of intracellular proteins. It can modify their stability, their activity, their subcellular location, and even their interacting pattern. This modification is a reversible event whose implementation is easy and fast. It contributes to the rapid adaptation of the cells to physiological intracellular variations and to intracellular or environmental stresses. E2F1 (E2 promoter binding factor 1) transcription factor is a potent cell cycle regulator. It displays contradictory functions able to regulate both cell proliferation and cell death. Its expression and activity are tightly regulated over the course of the cell cycle progression and in response to genotoxic stress. I discuss here the most recent evidence demonstrating the role of ubiquitination in E2F1’s regulation.
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Affiliation(s)
- Laurence Dubrez
- Université de Bourgogne Franche-Comté, LNC UMR1231, 21000 Dijon, France.
- Institut National de la Santé et de la Recherche Médicale (Inserm), LNC UMR1231, 21000 Dijon, France.
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19
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Glorian V, Allègre J, Berthelet J, Dumetier B, Boutanquoi PM, Droin N, Kayaci C, Cartier J, Gemble S, Marcion G, Gonzalez D, Boidot R, Garrido C, Michaud O, Solary E, Dubrez L. DNA damage and S phase-dependent E2F1 stabilization requires the cIAP1 E3-ubiquitin ligase and is associated with K63-poly-ubiquitination on lysine 161/164 residues. Cell Death Dis 2017; 8:e2816. [PMID: 28542143 PMCID: PMC5520736 DOI: 10.1038/cddis.2017.222] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 04/06/2017] [Accepted: 04/13/2017] [Indexed: 12/14/2022]
Abstract
The E2F transcription factor 1 is subtly regulated along the cell cycle progression and in response to DNA damage by post-translational modifications. Here, we demonstrated that the E3-ubiquitin ligase cellular inhibitor of apoptosis 1 (cIAP1) increases E2F1 K63-poly-ubiquitination on the lysine residue 161/164 cluster, which is associated with the transcriptional factor stability and activity. Mutation of these lysine residues completely abrogates the binding of E2F1 to CCNE, TP73 and APAF1 promoters, thus inhibiting transcriptional activation of these genes and E2F1-mediated cell proliferation control. Importantly, E2F1 stabilization in response to etoposide-induced DNA damage or during the S phase of cell cycle, as revealed by cyclin A silencing, is associated with K63-poly-ubiquitinylation of E2F1 on lysine 161/164 residues and involves cIAP1. Our results reveal an additional level of regulation of the stability and the activity of E2F1 by a non-degradative K63-poly-ubiquitination and uncover a novel function for the E3-ubiquitin ligase cIAP1.
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Affiliation(s)
- Valérie Glorian
- Université de Bourgogne Franche-Comté, LNC UMR1231, Dijon, France.,Institut National de la Santé et de la Recherche Médicale (Inserm), LNC UMR1231, Dijon, France
| | - Jennifer Allègre
- Université de Bourgogne Franche-Comté, LNC UMR1231, Dijon, France.,Institut National de la Santé et de la Recherche Médicale (Inserm), LNC UMR1231, Dijon, France
| | - Jean Berthelet
- Université de Bourgogne Franche-Comté, LNC UMR1231, Dijon, France.,Institut National de la Santé et de la Recherche Médicale (Inserm), LNC UMR1231, Dijon, France
| | - Baptiste Dumetier
- Université de Bourgogne Franche-Comté, LNC UMR1231, Dijon, France.,Institut National de la Santé et de la Recherche Médicale (Inserm), LNC UMR1231, Dijon, France
| | - Pierre-Marie Boutanquoi
- Université de Bourgogne Franche-Comté, LNC UMR1231, Dijon, France.,Institut National de la Santé et de la Recherche Médicale (Inserm), LNC UMR1231, Dijon, France
| | | | - Cémile Kayaci
- Université de Bourgogne Franche-Comté, LNC UMR1231, Dijon, France.,Institut National de la Santé et de la Recherche Médicale (Inserm), LNC UMR1231, Dijon, France
| | - Jessy Cartier
- Université de Bourgogne Franche-Comté, LNC UMR1231, Dijon, France.,Institut National de la Santé et de la Recherche Médicale (Inserm), LNC UMR1231, Dijon, France
| | - Simon Gemble
- Université de Bourgogne Franche-Comté, LNC UMR1231, Dijon, France.,Institut National de la Santé et de la Recherche Médicale (Inserm), LNC UMR1231, Dijon, France
| | - Guillaume Marcion
- Université de Bourgogne Franche-Comté, LNC UMR1231, Dijon, France.,Institut National de la Santé et de la Recherche Médicale (Inserm), LNC UMR1231, Dijon, France
| | - Daniel Gonzalez
- Université de Bourgogne Franche-Comté, LNC UMR1231, Dijon, France.,Institut National de la Santé et de la Recherche Médicale (Inserm), LNC UMR1231, Dijon, France.,Centre Georges-François Leclerc, Dijon, France
| | - Romain Boidot
- Université de Bourgogne Franche-Comté, LNC UMR1231, Dijon, France.,Institut National de la Santé et de la Recherche Médicale (Inserm), LNC UMR1231, Dijon, France.,Centre Georges-François Leclerc, Dijon, France
| | - Carmen Garrido
- Université de Bourgogne Franche-Comté, LNC UMR1231, Dijon, France.,Institut National de la Santé et de la Recherche Médicale (Inserm), LNC UMR1231, Dijon, France
| | - Olivier Michaud
- Université de Bourgogne Franche-Comté, LNC UMR1231, Dijon, France.,Institut National de la Santé et de la Recherche Médicale (Inserm), LNC UMR1231, Dijon, France
| | - Eric Solary
- Inserm U1170, Gustave Roussy, Villejuif, France.,Université Paris-Sud, Faculté de Médecine, Le Kremlin Bicêtre, France
| | - Laurence Dubrez
- Université de Bourgogne Franche-Comté, LNC UMR1231, Dijon, France.,Institut National de la Santé et de la Recherche Médicale (Inserm), LNC UMR1231, Dijon, France
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20
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APC/C and retinoblastoma interaction: cross-talk of retinoblastoma protein with the ubiquitin proteasome pathway. Biosci Rep 2016; 36:BSR20160152. [PMID: 27402801 PMCID: PMC5025812 DOI: 10.1042/bsr20160152] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 07/08/2016] [Indexed: 12/15/2022] Open
Abstract
The ubiquitin (Ub) ligase anaphase promoting complex/cyclosome (APC/C) and the tumour suppressor retinoblastoma protein (pRB) play key roles in cell cycle regulation. APC/C is a critical regulator of mitosis and G1-phase of the cell cycle whereas pRB keeps a check on proliferation by inhibiting transition to the S-phase. APC/C and pRB interact with each other via the co-activator of APC/C, FZR1, providing an alternative pathway of regulation of G1 to S transition by pRB using a post-translational mechanism. Both pRB and FZR1 have complex roles and are implicated not only in regulation of cell proliferation but also in differentiation, quiescence, apoptosis, maintenance of chromosomal integrity and metabolism. Both are also targeted by transforming viruses. We discuss recent advances in our understanding of the involvement of APC/C and pRB in cell cycle based decisions and how these insights will be useful for development of anti-cancer and anti-viral drugs.
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21
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Galanos P, Vougas K, Walter D, Polyzos A, Maya-Mendoza A, Haagensen EJ, Kokkalis A, Roumelioti FM, Gagos S, Tzetis M, Canovas B, Igea A, Kanavakis E, Kletsas D, Roninson I, Garbis SD, Nebreda A, Thanos D, Townsend P, Blow JJ, Sørensen CS, Bartek J, Gorgoulis VG. Chronic p53-independent p21 expression causes genomic instability by deregulating replication licensing. Nat Cell Biol 2016; 18:777-89. [PMID: 27323328 PMCID: PMC6535144 DOI: 10.1038/ncb3378] [Citation(s) in RCA: 218] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 05/19/2016] [Indexed: 12/17/2022]
Abstract
The cyclin-dependent kinase inhibitor p21(WAF1/CIP1) (p21) is a cell-cycle checkpoint effector and inducer of senescence, regulated by p53. Yet, evidence suggests that p21 could also be oncogenic, through a mechanism that has so far remained obscure. We report that a subset of atypical cancerous cells strongly expressing p21 showed proliferation features. This occurred predominantly in p53-mutant human cancers, suggesting p53-independent upregulation of p21 selectively in more aggressive tumour cells. Multifaceted phenotypic and genomic analyses of p21-inducible, p53-null, cancerous and near-normal cellular models showed that after an initial senescence-like phase, a subpopulation of p21-expressing proliferating cells emerged, featuring increased genomic instability, aggressiveness and chemoresistance. Mechanistically, sustained p21 accumulation inhibited mainly the CRL4-CDT2 ubiquitin ligase, leading to deregulated origin licensing and replication stress. Collectively, our data reveal the tumour-promoting ability of p21 through deregulation of DNA replication licensing machinery-an unorthodox role to be considered in cancer treatment, since p21 responds to various stimuli including some chemotherapy drugs.
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Affiliation(s)
- Panagiotis Galanos
- Molecular Carcinogenesis Group, Department of Histology and Embryology, School of Medicine, University of Athens, Athens, Greece
| | - Konstantinos Vougas
- Molecular Carcinogenesis Group, Department of Histology and Embryology, School of Medicine, University of Athens, Athens, Greece
- Biomedical Research Foundation of the Academy of Athens, Athens, Greece
| | - David Walter
- Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark
| | - Alexander Polyzos
- Biomedical Research Foundation of the Academy of Athens, Athens, Greece
| | | | - Emma J. Haagensen
- Centre for Gene Regulation & Expression, College of Life Sciences, University of Dundee, Dundee, UK
| | - Antonis Kokkalis
- Biomedical Research Foundation of the Academy of Athens, Athens, Greece
| | | | - Sarantis Gagos
- Biomedical Research Foundation of the Academy of Athens, Athens, Greece
| | - Maria Tzetis
- Department of Medical Genetics, Medical School, University of Athens, Athens, Greece
| | - Begoña Canovas
- Institute for Research in Biomedicine (IRB Barcelona), Barcelona, Spain
| | - Ana Igea
- Institute for Research in Biomedicine (IRB Barcelona), Barcelona, Spain
| | - Emanuel Kanavakis
- Department of Medical Genetics, Medical School, University of Athens, Athens, Greece
| | - Dimitris Kletsas
- Laboratory of Cell Proliferation and Ageing, Institute of Biology, National Centre for Scientific Research ‘Demokritos’, Athens, Greece
| | - Igor Roninson
- Cancer Center, Ordway Research Institute, Albany, NY, USA
| | - Spiros D. Garbis
- Cancer and Clinical Experimental Science Units, Faculty of Medicine, Institute for Life Sciences, Center for Proteome Research, University of Southampton, Southampton, UK
| | - Angel Nebreda
- Institute for Research in Biomedicine (IRB Barcelona), Barcelona, Spain
| | - Dimitris Thanos
- Biomedical Research Foundation of the Academy of Athens, Athens, Greece
| | - Paul Townsend
- Faculty Institute of Cancer Sciences, University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
- Manchester Centre for Cellular Metabolism, University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - J. Julian Blow
- Centre for Gene Regulation & Expression, College of Life Sciences, University of Dundee, Dundee, UK
| | | | - Jiri Bartek
- Genome Integrity Unit, Danish Cancer Society Research Centre, Copenhagen, Denmark
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacky University, Olomouc, Czech Republic
| | - Vassilis G. Gorgoulis
- Molecular Carcinogenesis Group, Department of Histology and Embryology, School of Medicine, University of Athens, Athens, Greece
- Biomedical Research Foundation of the Academy of Athens, Athens, Greece
- Faculty Institute of Cancer Sciences, University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
- Manchester Centre for Cellular Metabolism, University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
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22
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Rahighi S, Braunstein I, Ternette N, Kessler B, Kawasaki M, Kato R, Matsui T, Weiss TM, Stanhill A, Wakatsuki S. Selective Binding of AIRAPL Tandem UIMs to Lys48-Linked Tri-Ubiquitin Chains. Structure 2016; 24:412-22. [PMID: 26876100 DOI: 10.1016/j.str.2015.12.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 12/20/2015] [Accepted: 12/21/2015] [Indexed: 11/16/2022]
Abstract
Lys48-linked ubiquitin chains act as the main targeting signals for protein degradation by the proteasome. Here we report selective binding of AIRAPL, a protein that associates with the proteasome upon exposure to arsenite, to Lys48-linked tri-ubiquitin chains. AIRAPL comprises two ubiquitin-interacting motifs in tandem (tUIMs) that are linked through a flexible inter-UIM region. In the complex crystal structure UIM1 binds the proximal ubiquitin, whereas UIM2 (the double-sided UIM) binds non-symmetrically to the middle and distal ubiquitin moieties on either side of the helix. Specificity of AIRAPL for Lys48-linked ubiquitin chains is determined by UIM2, and the flexible inter-UIM linker increases avidity by placing the two UIMs in an orientation that facilitates binding of the third ubiquitin to UIM1. Unlike middle and proximal ubiquitins, distal ubiquitin binds UIM2 through a novel surface, which leaves the Ile44 hydrophobic patch accessible for binding to the proteasomal ubiquitin receptors.
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Affiliation(s)
- Simin Rahighi
- Structural Biology Research Center, Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan; Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Ilana Braunstein
- Department of Biochemistry, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Bat Galim, Haifa 31096, Israel
| | - Nicola Ternette
- TDI MS Laboratory, Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7FZ, UK
| | - Benedikt Kessler
- TDI MS Laboratory, Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7FZ, UK
| | - Masato Kawasaki
- Structural Biology Research Center, Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - Ryuichi Kato
- Structural Biology Research Center, Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - Tsutomu Matsui
- Structural Molecular Biology, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Thomas M Weiss
- Structural Molecular Biology, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Ariel Stanhill
- Department of Biochemistry, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Bat Galim, Haifa 31096, Israel.
| | - Soichi Wakatsuki
- Structural Biology Research Center, Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan; Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA; Structural Molecular Biology, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA; Photon Science, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA.
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23
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Boekhout M, Yuan R, Wondergem AP, Segeren HA, van Liere EA, Awol N, Jansen I, Wolthuis RMF, de Bruin A, Westendorp B. Feedback regulation between atypical E2Fs and APC/CCdh1 coordinates cell cycle progression. EMBO Rep 2016; 17:414-27. [PMID: 26882548 DOI: 10.15252/embr.201540984] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 01/07/2016] [Indexed: 01/20/2023] Open
Abstract
E2F transcription factors control the oscillating expression pattern of multiple target genes during the cell cycle. Activator E2Fs, E2F1-3, induce an upswing of E2F targets, which is essential for the G1-to-S phase transition, whereas atypical E2Fs, E2F7 and E2F8, mediate a downswing of the same targets during late S, G2, and M phases. Expression of atypical E2Fs is induced by E2F1-3, but it is unknown how atypical E2Fs are inactivated in a timely manner. Here, we demonstrate that E2F7 and E2F8 are substrates of the anaphase-promoting complex/cyclosome (APC/C). Removal of CDH1, or mutating the CDH1-interacting KEN boxes, stabilized E2F7/8 from anaphase onwards and during G1. Expressing KEN mutant E2F7 during G1 impairs S phase entry and eventually results in cell death. Furthermore, we show that E2F8, but not E2F7, interacts also with APC/C(C) (dc20). Importantly, atypical E2Fs can activate APC/C(C) (dh1) by repressing its inhibitors cyclin A, cyclin E, and Emi1. In conclusion, we discovered a feedback loop between atypical E2Fs and APC/C(C) (dh1), which ensures balanced expression of cell cycle genes and normal cell cycle progression.
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Affiliation(s)
- Michiel Boekhout
- Division of Cell Biology I (B5), The Netherlands Cancer Institute (NKI-AvL), Amsterdam, The Netherlands
| | - Ruixue Yuan
- Department of Pathobiology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Annelotte P Wondergem
- Department of Pathobiology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Hendrika A Segeren
- Department of Pathobiology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Elsbeth A van Liere
- Department of Pathobiology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Nesibu Awol
- Department of Pathobiology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Imke Jansen
- Department of Pathobiology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Rob M F Wolthuis
- Division of Cell Biology I (B5), The Netherlands Cancer Institute (NKI-AvL), Amsterdam, The Netherlands
| | - Alain de Bruin
- Department of Pathobiology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands Department of Pediatrics, Division of Molecular Genetics, University Medical Center Groningen University of Groningen, Groningen, The Netherlands
| | - Bart Westendorp
- Department of Pathobiology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
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24
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Wang B, Ma A, Zhang L, Jin WL, Qian Y, Xu G, Qiu B, Yang Z, Liu Y, Xia Q, Liu Y. POH1 deubiquitylates and stabilizes E2F1 to promote tumour formation. Nat Commun 2015; 6:8704. [PMID: 26510456 PMCID: PMC4846323 DOI: 10.1038/ncomms9704] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 09/23/2015] [Indexed: 12/29/2022] Open
Abstract
Hyperactivation of the transcriptional factor E2F1 occurs frequently in human cancers and contributes to malignant progression. E2F1 activity is regulated by proteolysis mediated by the ubiquitin–proteasome system. However, the deubiquitylase that controls E2F1 ubiquitylation and stability remains undefined. Here we demonstrate that the deubiquitylase POH1 stabilizes E2F1 protein through binding to and deubiquitylating E2F1. Conditional knockout of Poh1 alleles results in reduced E2F1 expression in primary mouse liver cells. The POH1-mediated regulation of E2F1 expression strengthens E2F1-downstream prosurvival signals, including upregulation of Survivin and FOXM1 protein levels, and efficiently facilitates tumour growth of liver cancer cells in nude mice. Importantly, human hepatocellular carcinomas (HCCs) recapitulate POH1 regulation of E2F1 expression, as nuclear abundance of POH1 is increased in HCCs and correlates with E2F1 overexpression and tumour growth. Thus, our study suggests that the hyperactivated POH1–E2F1 regulation may contribute to the development of liver cancer. The transcription factor E2F1 controls the expression of multiple genes and is frequently overactivated in cancer. Here, the authors show that E2F1 is deubiquitinated by POH1 and that this enhances the role of E2F1 in cell survival, and contributes to the pathogenesis of liver cancer.
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Affiliation(s)
- Boshi Wang
- State Key laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200032, China
| | - Aihui Ma
- State Key laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200032, China
| | - Li Zhang
- State Key laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200032, China
| | - Wei-Lin Jin
- Institute of Nano Biomedicine and Engineering, Department of Instrument Science and Engineering, Key Laboratory for Thin Film and Microfabrication Technology of Ministry of Education, School of Electronic Information and Electronic Engineering, Shanghai Jiaotong University, Shanghai 200240, China
| | - Yu Qian
- State Key laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200032, China
| | - Guiqin Xu
- State Key laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200032, China
| | - Bijun Qiu
- Department of Liver Surgery, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200217, China
| | - Zhaojuan Yang
- State Key laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200032, China
| | - Yun Liu
- State Key laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200032, China
| | - Qiang Xia
- Department of Liver Surgery, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200217, China
| | - Yongzhong Liu
- State Key laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200032, China
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25
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Mahanic CS, Budhavarapu V, Graves JD, Li G, Lin WC. Regulation of E2 promoter binding factor 1 (E2F1) transcriptional activity through a deubiquitinating enzyme, UCH37. J Biol Chem 2015; 290:26508-22. [PMID: 26396186 DOI: 10.1074/jbc.m115.659425] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Indexed: 01/27/2023] Open
Abstract
E2F1 is tightly controlled by multiple mechanisms, but whether ubiquitination regulates its transcriptional activity remains unknown. Here we identify UCH37 as the first, to our knowledge, deubiquitinating enzyme for E2F1. UCH37 does not deubiquitinate UbK48 chains or affect E2F1 protein stability. Instead, UCH37, but not a catalytically dead mutant, decreases the Lys-63-linked ubiquitination of E2F1 and activates its transcriptional activity. UCH37 depletion reduces the gene expression of both proliferative and pro-apoptotic E2F1 target genes. UCH37 depletion also decreases both cell proliferation and apoptosis induction in functional assays. Interestingly, UCH37 expression is induced by E2F1, and its level rises in G1/S transition and S phase, suggesting a positive feedback loop between UCH37 and E2F1. UCH37 protein and mRNA levels are also induced after DNA damage. UCH37 localizes to the promoters of E2F1 pro-apoptotic target genes such as caspase 3, caspase 7, PARP1, and Apaf-1 and activates their expression after DNA damage. Moreover, the expression of E2F1 proliferative and pro-apoptotic genes is correlated with the levels of UCH37 in many primary tumors. These results uncover a novel mechanism for E2F1 transcriptional activation through removal of its Lys-63-linked ubiquitination by UCH37.
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Affiliation(s)
- Christina S Mahanic
- From the Section of Hematology/Oncology and Integrative Molecular and Biomedical Sciences Graduate Program, Departments of Medicine and Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030
| | | | - Joshua D Graves
- From the Section of Hematology/Oncology and Integrative Molecular and Biomedical Sciences Graduate Program, Departments of Medicine and Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030
| | - Gang Li
- From the Section of Hematology/Oncology and
| | - Weei-Chin Lin
- From the Section of Hematology/Oncology and Integrative Molecular and Biomedical Sciences Graduate Program, Departments of Medicine and Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030
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26
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Moniz S, Bandarra D, Biddlestone J, Campbell KJ, Komander D, Bremm A, Rocha S. Cezanne regulates E2F1-dependent HIF2α expression. J Cell Sci 2015; 128:3082-93. [PMID: 26148512 PMCID: PMC4541044 DOI: 10.1242/jcs.168864] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Accepted: 06/25/2015] [Indexed: 02/04/2023] Open
Abstract
Mechanisms regulating protein degradation ensure the correct and timely expression of transcription factors such as hypoxia inducible factor (HIF). Under normal O2 tension, HIFα subunits are targeted for proteasomal degradation, mainly through vHL-dependent ubiquitylation. Deubiquitylases are responsible for reversing this process. Although the mechanism and regulation of HIFα by ubiquitin-dependent proteasomal degradation has been the object of many studies, little is known about the role of deubiquitylases. Here, we show that expression of HIF2α (encoded by EPAS1) is regulated by the deubiquitylase Cezanne (also known as OTUD7B) in an E2F1-dependent manner. Knockdown of Cezanne downregulates HIF2α mRNA, protein and activity independently of hypoxia and proteasomal degradation. Mechanistically, expression of the HIF2α gene is controlled directly by E2F1, and Cezanne regulates the stability of E2F1. Exogenous E2F1 can rescue HIF2α transcript and protein expression when Cezanne is depleted. Taken together, these data reveal a novel mechanism for the regulation of the expression of HIF2α, demonstrating that the HIF2α promoter is regulated by E2F1 directly and that Cezanne regulates HIF2α expression through control of E2F1 levels. Our results thus suggest that HIF2α is controlled transcriptionally in a cell-cycle-dependent manner and in response to oncogenic signalling.
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Affiliation(s)
- Sonia Moniz
- Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Daniel Bandarra
- Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - John Biddlestone
- Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | | | - David Komander
- Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, UK
| | - Anja Bremm
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Max-von-Laue-Strasse 15, Frankfurt am Main 60438, Germany
| | - Sonia Rocha
- Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
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27
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Targeting Cdc20 as a novel cancer therapeutic strategy. Pharmacol Ther 2015; 151:141-51. [PMID: 25850036 DOI: 10.1016/j.pharmthera.2015.04.002] [Citation(s) in RCA: 172] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 03/31/2015] [Indexed: 12/25/2022]
Abstract
The Anaphase Promoting Complex (APC, also called APC/C) regulates cell cycle progression by forming two closely related, but functionally distinct E3 ubiquitin ligase sub-complexes, APC(Cdc20) and APC(Cdh1), respectively. Emerging evidence has begun to reveal that Cdc20 and Cdh1 have opposing functions in tumorigenesis. Specifically, Cdh1 functions largely as a tumor suppressor, whereas Cdc20 exhibits an oncogenic function, suggesting that Cdc20 could be a promising therapeutic target for combating human cancer. However, the exact underlying molecular mechanisms accounting for their differences in tumorigenesis remain largely unknown. Therefore, in this review, we summarize the downstream substrates of Cdc20 and the critical functions of Cdc20 in cell cycle progression, apoptosis, ciliary disassembly and brain development. Moreover, we briefly describe the upstream regulators of Cdc20 and the oncogenic role of Cdc20 in a variety of human malignancies. Furthermore, we summarize multiple pharmacological Cdc20 inhibitors including TAME and Apcin, and their potential clinical benefits. Taken together, development of specific Cdc20 inhibitors could be a novel strategy for the treatment of human cancers with elevated Cdc20 expression.
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28
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Poppy Roworth A, Ghari F, La Thangue NB. To live or let die - complexity within the E2F1 pathway. Mol Cell Oncol 2015; 2:e970480. [PMID: 27308406 PMCID: PMC4905241 DOI: 10.4161/23723548.2014.970480] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 09/11/2014] [Accepted: 09/11/2014] [Indexed: 04/21/2023]
Abstract
The E2F1 transcription factor is a recognized regulator of the cell cycle as well as a potent mediator of DNA damage-induced apoptosis and the checkpoint response. Understanding the diverse and seemingly dichotomous functions of E2F1 activity has been the focus of extensive ongoing research. Although the E2F pathway is frequently deregulated in cancer, the contributions of E2F1 itself to tumorigenesis, as a promoter of proliferation or cell death, are far from understood. In this review we aim to provide an update on our current understanding of E2F1, with particular insight into its novel interaction partners and post-translational modifications, as a means to explaining its diverse functional complexity.
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Affiliation(s)
- A Poppy Roworth
- Laboratory of Cancer Biology; Department of Oncology; University of Oxford; Oxford, UK
| | - Fatemeh Ghari
- Laboratory of Cancer Biology; Department of Oncology; University of Oxford; Oxford, UK
| | - Nicholas B La Thangue
- Laboratory of Cancer Biology; Department of Oncology; University of Oxford; Oxford, UK
- Correspondence to: Nicholas B La Thangue;
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29
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Qin Y, Zhou MT, Hu MM, Hu YH, Zhang J, Guo L, Zhong B, Shu HB. RNF26 temporally regulates virus-triggered type I interferon induction by two distinct mechanisms. PLoS Pathog 2014; 10:e1004358. [PMID: 25254379 PMCID: PMC4177927 DOI: 10.1371/journal.ppat.1004358] [Citation(s) in RCA: 150] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2014] [Accepted: 07/25/2014] [Indexed: 12/15/2022] Open
Abstract
Viral infection triggers induction of type I interferons (IFNs), which are critical mediators of innate antiviral immune response. Mediator of IRF3 activation (MITA, also called STING) is an adapter essential for virus-triggered IFN induction pathways. How post-translational modifications regulate the activity of MITA is not fully elucidated. In expression screens, we identified RING finger protein 26 (RNF26), an E3 ubiquitin ligase, could mediate polyubiquitination of MITA. Interestingly, RNF26 promoted K11-linked polyubiquitination of MITA at lysine 150, a residue also targeted by RNF5 for K48-linked polyubiquitination. Further experiments indicated that RNF26 protected MITA from RNF5-mediated K48-linked polyubiquitination and degradation that was required for quick and efficient type I IFN and proinflammatory cytokine induction after viral infection. On the other hand, RNF26 was required to limit excessive type I IFN response but not proinflammatory cytokine induction by promoting autophagic degradation of IRF3. Consistently, knockdown of RNF26 inhibited the expression of IFNB1 gene in various cells at the early phase and promoted it at the late phase of viral infection, respectively. Furthermore, knockdown of RNF26 inhibited viral replication, indicating that RNF26 antagonizes cellular antiviral response. Our findings thus suggest that RNF26 temporally regulates innate antiviral response by two distinct mechanisms. Virus infection induces the host cells to produce type I interferons, which are secreted proteins important for the host to clear viruses. Previously, we identified a cellular protein called MITA, which is essential for virus-triggered induction of interferons. In this study, we found an enzyme called RNF26 could covalently modify MITA with one type of polypeptide, called polyubiquitin. This modification caused increased stability of MITA after viral infection. RNF26 also caused disability of IRF3, another important component required for virus-triggered interferon induction. Thus, RNF26 could temporally regulate virus-triggered interferon induction by two distinct mechanisms. This discovery helps to understand how the antiviral response is delicately regulated.
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Affiliation(s)
- Yue Qin
- State Key Laboratory of Virology, Medical Research Institute, College of Life Sciences, Wuhan University, Wuhan, China
| | - Mao-Tian Zhou
- State Key Laboratory of Virology, Medical Research Institute, College of Life Sciences, Wuhan University, Wuhan, China
| | - Ming-Ming Hu
- State Key Laboratory of Virology, Medical Research Institute, College of Life Sciences, Wuhan University, Wuhan, China
| | - Yun-Hong Hu
- State Key Laboratory of Virology, Medical Research Institute, College of Life Sciences, Wuhan University, Wuhan, China
| | - Jing Zhang
- State Key Laboratory of Virology, Medical Research Institute, College of Life Sciences, Wuhan University, Wuhan, China
| | - Lin Guo
- State Key Laboratory of Virology, Medical Research Institute, College of Life Sciences, Wuhan University, Wuhan, China
| | - Bo Zhong
- State Key Laboratory of Virology, Medical Research Institute, College of Life Sciences, Wuhan University, Wuhan, China
| | - Hong-Bing Shu
- State Key Laboratory of Virology, Medical Research Institute, College of Life Sciences, Wuhan University, Wuhan, China
- * E-mail:
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30
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Hainline SG, Rickmyre JL, Neitzel LR, Lee LA, Lee E. The Drosophila MCPH1-B isoform is a substrate of the APCCdh1 E3 ubiquitin ligase complex. Biol Open 2014; 3:669-76. [PMID: 24972868 PMCID: PMC4154303 DOI: 10.1242/bio.20148318] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The Anaphase-Promoting Complex (APC) is a multi-subunit E3 ubiquitin ligase that coordinates progression through the cell cycle by temporally and spatially promoting the degradation of key proteins. Many of these targeted proteins have been shown to play important roles in regulating orderly progression through the cell cycle. Using a previously described Drosophila in vitro expression cloning approach, we screened for new substrates of the APC in Xenopus egg extract and identified Drosophila MCPH1 (dMCPH1), a protein encoded by the homolog of a causative gene for autosomal recessive primary microcephaly in humans. The dMCPH1-B splice form, but not the dMCPH1-C splice form, undergoes robust degradation in Xenopus interphase egg extract in a Cdh1-dependent manner. Degradation of dMCPH1-B is controlled by an N-terminal destruction box (D-box) motif as its deletion or mutation blocks dMCPH1-B degradation. dMCPH1 levels are increased in Drosophila morula (APC2) mutant embryos, consistent with dMCPH1 being an APC substrate in vivo. Using a purified, reconstituted system, we show that dMCPH1-B is ubiquitinated by APCCdh1, indicating that the effect of APC on dMCPH1-B ubiquitination and degradation is direct. Full-length human MCPH1 (hMCPH1) has been predicted to be an APC substrate based on its interaction with the APC subunit Cdc27. We were not able to detect changes in hMCPH1 levels during the cell cycle in cultured human cells. Overexpression of hMCPH1 (or dMCPH1-B) in developing Xenopus embryos, however, disrupts cell division, suggesting that proper regulation of hMCPH1 and dMCPH1-B activity plays a critical role in proper cell-cycle progression.
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Affiliation(s)
- Sarah G Hainline
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232-8240, USA Present address: Sarah Cannon Research Institute, Nashville, TN 37203, USA
| | - Jamie L Rickmyre
- Present address: Sarah Cannon Research Institute, Nashville, TN 37203, USA
| | - Leif R Neitzel
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232-8240, USA Present address: Sarah Cannon Research Institute, Nashville, TN 37203, USA
| | - Laura A Lee
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232-8240, USA Present address: Sarah Cannon Research Institute, Nashville, TN 37203, USA.
| | - Ethan Lee
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232-8240, USA Present address: Sarah Cannon Research Institute, Nashville, TN 37203, USA.
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Zhang J, Wan L, Dai X, Sun Y, Wei W. Functional characterization of Anaphase Promoting Complex/Cyclosome (APC/C) E3 ubiquitin ligases in tumorigenesis. Biochim Biophys Acta Rev Cancer 2014; 1845:277-93. [PMID: 24569229 DOI: 10.1016/j.bbcan.2014.02.001] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2013] [Revised: 02/09/2014] [Accepted: 02/12/2014] [Indexed: 12/25/2022]
Abstract
The Anaphase Promoting Complex/Cyclosome (APC/C) is a multi-subunit E3 ubiquitin ligase that primarily governs cell cycle progression. APC/C is composed of at least 14 core subunits and recruits its substrates for ubiquitination via one of the two adaptor proteins, Cdc20 or Cdh1, in M or M/early G1 phase, respectively. Furthermore, recent studies have shed light on crucial functions for APC/C in maintaining genomic integrity, neuronal differentiation, cellular metabolism and tumorigenesis. To gain better insight into the in vivo physiological functions of APC/C in regulating various cellular processes, particularly development and tumorigenesis, a number of mouse models of APC/C core subunits, coactivators or inhibitors have been established and characterized. However, due to their essential role in cell cycle regulation, most of the germline knockout mice targeting the APC/C pathway are embryonic lethal, indicating the need for generating conditional knockout mouse models to assess the role in tumorigenesis for each APC/C signaling component in specific tissues. In this review, we will first provide a brief introduction of the ubiquitin-proteasome system (UPS) and the biochemical activities and cellular functions of the APC/C E3 ligase. We will then focus primarily on characterizing genetic mouse models used to understand the physiological roles of each APC/C signaling component in embryogenesis, cell proliferation, development and carcinogenesis. Finally, we discuss future research directions to further elucidate the physiological contributions of APC/C components during tumorigenesis and validate their potentials as a novel class of anti-cancer targets.
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Affiliation(s)
- Jinfang Zhang
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Lixin Wan
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Xiangpeng Dai
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Yi Sun
- Division of Radiation and Cancer Biology, Department of Radiation Oncology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Wenyi Wei
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
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Cohen M, Vecsler M, Liberzon A, Noach M, Zlotorynski E, Tzur A. Unbiased transcriptome signature of in vivo cell proliferation reveals pro- and antiproliferative gene networks. Cell Cycle 2013; 12:2992-3000. [PMID: 23974109 PMCID: PMC3875674 DOI: 10.4161/cc.26030] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Different types of mature B-cell lymphocytes are overall highly similar. Nevertheless, some B cells proliferate intensively, while others rarely do. Here, we demonstrate that a simple binary classification of gene expression in proliferating vs. resting B cells can identify, with remarkable selectivity, global in vivo regulators of the mammalian cell cycle, many of which are also post-translationally regulated by the APC/C E3 ligase. Consequently, we discover a novel regulatory network between the APC/C and the E2F transcription factors and discuss its potential impact on the G1-S transition of the cell cycle. In addition, by focusing on genes whose expression inversely correlates with proliferation, we demonstrate the inherent ability of our approach to also identify in vivo regulators of cell differentiation, cell survival, and other antiproliferative processes. Relying on data sets of wt, non-transgenic animals, our approach can be applied to other cell lineages and human data sets.
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Affiliation(s)
- Meital Cohen
- The Mina and Everard Goodman Faculty of Life Sciences; Bar-Ilan University; Ramat-Gan, Israel; Advanced Materials and Nanotechnology Institute; Bar-Ilan University; Ramat-Gan, Israel
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Swarnalatha M, Singh AK, Kumar V. Promoter occupancy of MLL1 histone methyltransferase seems to specify the proliferative and apoptotic functions of E2F1 in a tumour microenvironment. J Cell Sci 2013; 126:4636-46. [PMID: 23868976 DOI: 10.1242/jcs.126235] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The E2F family of transcription factors are considered versatile modulators, poised at biological crossroads to execute diverse cellular functions. Despite extensive studies on E2F, the molecular mechanisms that control specific biological functions of the E2F1 transcription factor are still not fully understood. Here we have addressed the molecular underpinnings of paradoxical functions of E2F1 in a tumour microenvironment using the 'X15-myc' oncomouse model of hepatocellular carcinoma. We observed that the HBx oncoprotein of hepatitis B virus regulates E2F1 functions by interfering with its binding to Skp2 E3 ubiquitin ligase. The HBx-Skp2 interaction led to the accumulation of transcriptionally active E2F1 and histone methyltransferase mixed lineage leukemia 1 (MLL1) protein. During early stages of hepatocarcinogenesis, the increased E2F1 activity promoted cellular proliferation by stimulating the genes involved in cell cycle control and replication. However, during the late stages, E2F1 triggered replication-stress-induced DNA damage and sensitized cells to apoptotic death in a p53-independent manner. Interestingly, the different promoter occupancy of MLL1 during the early and late stages of tumour development seemed to specify the proliferative and apoptotic functions of E2F1, through its dynamic interaction with the co-activator CBP or co-repressor Brg1. Thus, the temporally regulated promoter occupancy of histone methyltransferase could be a regulatory mechanism associated with the diverse cellular functions of the E2F family of transcription factors.
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Affiliation(s)
- Manickavinayaham Swarnalatha
- Virology Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India
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Abstract
The cell cycle ensures genome maintenance by coordinating the processes of DNA replication and chromosome segregation. Of particular importance is the irreversible transition from the G1 phase of the cell cycle to S phase. This transition marks the switch from preparing chromosomes for replication ("origin licensing") to active DNA synthesis ("origin firing"). Ubiquitin-mediated proteolysis is essential for restricting DNA replication to only once per cell cycle and is the major mechanism regulating the G1 to S phase transition. Although some changes in protein levels are attributable to regulated mRNA abundance, protein degradation elicits very rapid changes in protein abundance and is critical for the sharp and irreversible transition from one cell cycle stage to the next. Not surprisingly, regulation of the G1-to-S phase transition is perturbed in most cancer cells, and deregulation of key molecular events in G1 and S phase drives not only cell proliferation but also genome instability. In this review we focus on the mechanisms by which E3 ubiquitin ligases control the irreversible transition from G1 to S phase in mammalian cells.
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Affiliation(s)
- Lindsay F Rizzardi
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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E2F1 apoptosis counterattacked: evil strikes back. Trends Mol Med 2013; 19:89-98. [DOI: 10.1016/j.molmed.2012.10.009] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Revised: 10/23/2012] [Accepted: 10/23/2012] [Indexed: 12/15/2022]
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