1
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Rankin BD, Rankin S. The MCM2-7 Complex: Roles beyond DNA Unwinding. BIOLOGY 2024; 13:258. [PMID: 38666870 PMCID: PMC11048021 DOI: 10.3390/biology13040258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 04/07/2024] [Accepted: 04/11/2024] [Indexed: 04/28/2024]
Abstract
The MCM2-7 complex is a hexameric protein complex that serves as a DNA helicase. It unwinds the DNA double helix during DNA replication, thereby providing the single-stranded replication template. In recent years, it has become clear that the MCM2-7 complex has additional functions that extend well beyond its role in DNA replication. Through physical and functional interactions with different pathways, it impacts other nuclear events and activities, including folding of the genome, histone inheritance, chromosome segregation, DNA damage sensing and repair, and gene transcription. Collectively, the diverse roles of the MCM2-7 complex suggest it plays a critical role in maintaining genome integrity by integrating the regulation of DNA replication with other pathways in the nucleus.
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Affiliation(s)
- Brooke D. Rankin
- Cell Cycle and Cancer Biology Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA;
- Cell Biology Department, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Susannah Rankin
- Cell Cycle and Cancer Biology Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA;
- Cell Biology Department, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
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2
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Inanc B, Fang Q, Andrews JF, Zeng X, Clark J, Li J, Dey NB, Ibrahim M, Sykora P, Yu Z, Braganza A, Verheij M, Jonkers J, Yates NA, Vens C, Sobol RW. TRIP12 governs DNA Polymerase β involvement in DNA damage response and repair. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.08.588474. [PMID: 38645048 PMCID: PMC11030427 DOI: 10.1101/2024.04.08.588474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/23/2024]
Abstract
The multitude of DNA lesion types, and the nuclear dynamic context in which they occur, present a challenge for genome integrity maintenance as this requires the engagement of different DNA repair pathways. Specific 'repair controllers' that facilitate DNA repair pathway crosstalk between double strand break (DSB) repair and base excision repair (BER), and regulate BER protein trafficking at lesion sites, have yet to be identified. We find that DNA polymerase β (Polβ), crucial for BER, is ubiquitylated in a BER complex-dependent manner by TRIP12, an E3 ligase that partners with UBR5 and restrains DSB repair signaling. Here we find that, TRIP12, but not UBR5, controls cellular levels and chromatin loading of Polβ. Required for Polβ foci formation, TRIP12 regulates Polβ involvement after DNA damage. Notably, excessive TRIP12-mediated shuttling of Polβ affects DSB formation and radiation sensitivity, underscoring its precedence for BER. We conclude that the herein discovered trafficking function at the nexus of DNA repair signaling pathways, towards Polβ-directed BER, optimizes DNA repair pathway choice at complex lesion sites.
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3
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Vogt M, Classen S, Krause AK, Peter NJ, Petersen C, Rothkamm K, Borgmann K, Meyer F. USP7 Deregulation Impairs S Phase Specific DNA Repair after Irradiation in Breast Cancer Cells. Biomedicines 2024; 12:762. [PMID: 38672118 PMCID: PMC11047985 DOI: 10.3390/biomedicines12040762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 03/13/2024] [Accepted: 03/19/2024] [Indexed: 04/28/2024] Open
Abstract
The ubiquitin specific protease 7 (USP7) is a deubiquitinating enzyme with numerous substrates. Aberrant expression of USP7 is associated with tumor progression. This study aims to investigate how a deregulated USP7 expression affects chromosomal instability and prognosis of breast cancer patients in silico and radiosensitivity and DNA repair in breast cancer cells in vitro. The investigations in silico were performed using overall survival and USP7 mRNA expression data of breast cancer patients. The results showed that a high USP7 expression was associated with increased chromosomal instability and decreased overall survival. The in vitro experiments were performed in a luminal and a triple-negative breast cancer cell line. Proliferation, DNA repair, DNA replication stress, and survival after USP7 overexpression or inhibition and irradiation were analyzed. Both, USP7 inhibition and overexpression resulted in decreased cellular survival, distinct radiosensitization and an increased number of residual DNA double-strand breaks in the S phase following irradiation. RAD51 recruitment and base incorporation were decreased after USP7 inhibition plus irradiation and more single-stranded DNA was detected. The results show that deregulation of USP7 activity disrupts DNA repair in the S phase by increasing DNA replication stress and presents USP7 as a promising target to overcome the radioresistance of breast tumors.
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Affiliation(s)
| | | | | | | | | | | | | | - Felix Meyer
- Department of Radiotherapy & Radiation Oncology, Hubertus Wald Tumor Center—University Cancer Center Hamburg, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany; (M.V.); (S.C.); (A.K.K.); (N.-J.P.); (C.P.); (K.R.); (K.B.)
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4
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Park HB, Baek KH. Current and future directions of USP7 interactome in cancer study. Biochim Biophys Acta Rev Cancer 2023; 1878:188992. [PMID: 37775071 DOI: 10.1016/j.bbcan.2023.188992] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 09/14/2023] [Accepted: 09/23/2023] [Indexed: 10/01/2023]
Abstract
The ubiquitin-proteasome system (UPS) is an essential protein quality controller for regulating protein homeostasis and autophagy. Ubiquitination is a protein modification process that involves the binding of one or more ubiquitins to substrates through a series of enzymatic processes. These include ubiquitin-activating enzymes (E1), ubiquitin-conjugating enzymes (E2), and ubiquitin ligases (E3). Conversely, deubiquitination is a reverse process that removes ubiquitin from substrates via deubiquitinating enzymes (DUBs). Dysregulation of ubiquitination-related enzymes can lead to various human diseases, including cancer, through the modulation of protein ubiquitination. The most structurally and functionally studied DUB is the ubiquitin-specific protease 7 (USP7). Both the TRAF and UBL domains of USP7 are known to bind to the [P/A/E]-X-X-S or K-X-X-X-K motif of substrates. USP7 has been shown to be involved in cancer pathogenesis by binding with numerous substrates. Recently, a novel substrate of USP7 was discovered through a systemic analysis of its binding motif. This review summarizes the currently discovered substrates and cellular functions of USP7 in cancer and suggests putative substrates of USP7 through a comprehensive systemic analysis.
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Affiliation(s)
- Hong-Beom Park
- Department of Convergence, CHA University, Gyeonggi-Do 13488, Republic of Korea
| | - Kwang-Hyun Baek
- Department of Convergence, CHA University, Gyeonggi-Do 13488, Republic of Korea; International Ubiquitin Center(,) CHA University, Gyeonggi-Do 13488, Republic of Korea.
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5
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Chi L, Wang H, Yu F, Gao C, Dai H, Si X, Liu L, Wang Z, Zheng J, Ke Y, Liu H, Zhang Q. Recent Progress of Ubiquitin-Specific-Processing Protease 7 Inhibitors. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2023. [DOI: 10.1134/s1068162023020073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
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6
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Al Adhami H, Vallet J, Schaal C, Schumacher P, Bardet AF, Dumas M, Chicher J, Hammann P, Daujat S, Weber M. Systematic identification of factors involved in the silencing of germline genes in mouse embryonic stem cells. Nucleic Acids Res 2023; 51:3130-3149. [PMID: 36772830 PMCID: PMC10123117 DOI: 10.1093/nar/gkad071] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 12/29/2022] [Accepted: 01/23/2023] [Indexed: 02/12/2023] Open
Abstract
In mammals, many germline genes are epigenetically repressed to prevent their illegitimate expression in somatic cells. To advance our understanding of the mechanisms restricting the expression of germline genes, we analyzed their chromatin signature and performed a CRISPR-Cas9 knock-out screen for genes involved in germline gene repression using a Dazl-GFP reporter system in mouse embryonic stem cells (mESCs). We show that the repression of germline genes mainly depends on the polycomb complex PRC1.6 and DNA methylation, which function additively in mESCs. Furthermore, we validated novel genes involved in the repression of germline genes and characterized three of them: Usp7, Shfm1 (also known as Sem1) and Erh. Inactivation of Usp7, Shfm1 or Erh led to the upregulation of germline genes, as well as retrotransposons for Shfm1, in mESCs. Mechanistically, USP7 interacts with PRC1.6 components, promotes PRC1.6 stability and presence at germline genes, and facilitates DNA methylation deposition at germline gene promoters for long term repression. Our study provides a global view of the mechanisms and novel factors required for silencing germline genes in embryonic stem cells.
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Affiliation(s)
- Hala Al Adhami
- University of Strasbourg, Strasbourg, France.,CNRS UMR7242, Biotechnology and Cell Signaling, 300 Bd Sébastien Brant, 67412, Illkirch Cedex, France
| | - Judith Vallet
- University of Strasbourg, Strasbourg, France.,CNRS UMR7242, Biotechnology and Cell Signaling, 300 Bd Sébastien Brant, 67412, Illkirch Cedex, France
| | - Celia Schaal
- University of Strasbourg, Strasbourg, France.,CNRS UMR7242, Biotechnology and Cell Signaling, 300 Bd Sébastien Brant, 67412, Illkirch Cedex, France
| | - Paul Schumacher
- University of Strasbourg, Strasbourg, France.,CNRS UMR7242, Biotechnology and Cell Signaling, 300 Bd Sébastien Brant, 67412, Illkirch Cedex, France.,Karlsruhe Institute of Technology (KIT), IAB, Department of Food Chemistry and Toxicology, 76131 Karlsruhe, Germany
| | - Anaïs Flore Bardet
- University of Strasbourg, Strasbourg, France.,CNRS UMR7242, Biotechnology and Cell Signaling, 300 Bd Sébastien Brant, 67412, Illkirch Cedex, France
| | - Michael Dumas
- University of Strasbourg, Strasbourg, France.,CNRS UMR7242, Biotechnology and Cell Signaling, 300 Bd Sébastien Brant, 67412, Illkirch Cedex, France
| | - Johana Chicher
- Plateforme protéomique Strasbourg Esplanade, CNRS, University of Strasbourg, 67000 Strasbourg, France
| | - Philippe Hammann
- Plateforme protéomique Strasbourg Esplanade, CNRS, University of Strasbourg, 67000 Strasbourg, France
| | - Sylvain Daujat
- University of Strasbourg, Strasbourg, France.,CNRS UMR7242, Biotechnology and Cell Signaling, 300 Bd Sébastien Brant, 67412, Illkirch Cedex, France
| | - Michael Weber
- University of Strasbourg, Strasbourg, France.,CNRS UMR7242, Biotechnology and Cell Signaling, 300 Bd Sébastien Brant, 67412, Illkirch Cedex, France
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7
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Miyashita R, Nishiyama A, Qin W, Chiba Y, Kori S, Kato N, Konishi C, Kumamoto S, Kozuka-Hata H, Oyama M, Kawasoe Y, Tsurimoto T, Takahashi TS, Leonhardt H, Arita K, Nakanishi M. The termination of UHRF1-dependent PAF15 ubiquitin signaling is regulated by USP7 and ATAD5. eLife 2023; 12:79013. [PMID: 36734974 PMCID: PMC9943068 DOI: 10.7554/elife.79013] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 02/02/2023] [Indexed: 02/04/2023] Open
Abstract
UHRF1-dependent ubiquitin signaling plays an integral role in the regulation of maintenance DNA methylation. UHRF1 catalyzes transient dual mono-ubiquitylation of PAF15 (PAF15Ub2), which regulates the localization and activation of DNMT1 at DNA methylation sites during DNA replication. Although the initiation of UHRF1-mediated PAF15 ubiquitin signaling has been relatively well characterized, the mechanisms underlying its termination and how they are coordinated with the completion of maintenance DNA methylation have not yet been clarified. This study shows that deubiquitylation by USP7 and unloading by ATAD5 (ELG1 in yeast) are pivotal processes for the removal of PAF15 from chromatin. On replicating chromatin, USP7 specifically interacts with PAF15Ub2 in a complex with DNMT1. USP7 depletion or inhibition of the interaction between USP7 and PAF15 results in abnormal accumulation of PAF15Ub2 on chromatin. Furthermore, we also find that the non-ubiquitylated form of PAF15 (PAF15Ub0) is removed from chromatin in an ATAD5-dependent manner. PAF15Ub2 was retained at high levels on chromatin when the catalytic activity of DNMT1 was inhibited, suggesting that the completion of maintenance DNA methylation is essential for the termination of UHRF1-mediated ubiquitin signaling. This finding provides a molecular understanding of how the maintenance DNA methylation machinery is disassembled at the end of the S phase.
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Affiliation(s)
- Ryota Miyashita
- Division of Cancer Cell Biology, The Institute of Medical Science, The University of TokyoTokyoJapan
| | - Atsuya Nishiyama
- Division of Cancer Cell Biology, The Institute of Medical Science, The University of TokyoTokyoJapan
| | - Weihua Qin
- Faculty of Biology, Ludwig-Maximilians-Universität MünchenMunichGermany
| | - Yoshie Chiba
- Division of Cancer Cell Biology, The Institute of Medical Science, The University of TokyoTokyoJapan
| | - Satomi Kori
- Structural Biology Laboratory, Graduate School of Medical Life Science, Yokohama City UniversityYokohamaJapan
| | - Norie Kato
- Structural Biology Laboratory, Graduate School of Medical Life Science, Yokohama City UniversityYokohamaJapan
| | - Chieko Konishi
- Division of Cancer Cell Biology, The Institute of Medical Science, The University of TokyoTokyoJapan
| | - Soichiro Kumamoto
- Division of Cancer Cell Biology, The Institute of Medical Science, The University of TokyoTokyoJapan
| | - Hiroko Kozuka-Hata
- Medical Proteomics Laboratory, The Institute of Medical Science, The University of TokyoTokyoJapan
| | - Masaaki Oyama
- Medical Proteomics Laboratory, The Institute of Medical Science, The University of TokyoTokyoJapan
| | - Yoshitaka Kawasoe
- Laboratory of Chromosome Biology, Department of Biology, Faculty of Science, Kyushu UniversityFukuokaJapan
| | - Toshiki Tsurimoto
- Laboratory of Chromosome Biology, Department of Biology, Faculty of Science, Kyushu UniversityFukuokaJapan
| | - Tatsuro S Takahashi
- Laboratory of Chromosome Biology, Department of Biology, Faculty of Science, Kyushu UniversityFukuokaJapan
| | | | - Kyohei Arita
- Structural Biology Laboratory, Graduate School of Medical Life Science, Yokohama City UniversityYokohamaJapan
| | - Makoto Nakanishi
- Division of Cancer Cell Biology, The Institute of Medical Science, The University of TokyoTokyoJapan
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8
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G 1/S Cell Cycle Induction by Epstein-Barr Virus BORF2 Is Mediated by P53 and APOBEC3B. J Virol 2022; 96:e0066022. [PMID: 36069545 PMCID: PMC9517719 DOI: 10.1128/jvi.00660-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Herpesvirus lytic infection causes cells to arrest at the G1/S phase of the cell cycle by poorly defined mechanisms. In a prior study using fluorescent ubiquitination-based cell cycle indicator (FUCCI) cells that express fluorescently tagged proteins marking different stages of the cell cycle, we showed that the Epstein-Barr virus (EBV) protein BORF2 induces the accumulation of G1/S cells, and that BORF2 affects p53 levels without affecting the p53 target protein p21. We also found that BORF2 specifically interacted with APOBEC3B (A3B) and forms perinuclear bodies with A3B that prevent A3B from mutating replicating EBV genomes. We now show that BORF2 also interacts with p53 and that A3B interferes with the BORF2-p53 interaction, although A3B and p53 engage distinct surfaces on BORF2. Cell cycle analysis showed that G1/S induction by BORF2 is abrogated when either p53 or A3B is silenced or when an A3B-binding mutant of BORF2 is used. Furthermore, silencing A3B in EBV lytic infection increased cell proliferation, supporting a role for A3B in G1/S arrest. These data suggest that the p53 induced by BORF2 is inactive when it binds BORF2, but is released and induces G1/S arrest when A3B is present and sequesters BORF2 in perinuclear bodies. Interestingly, this mechanism is conserved in the BORF2 homologue in HSV-1, which also re-localizes A3B, induces and binds p53, and induces G1/S dependent on A3B and p53. In summary, we have identified a new mechanism by which G1/S arrest can be induced in herpesvirus lytic infection. IMPORTANCE In lytic infection, herpesviruses cause cells to arrest at the G1/S phase of the cell cycle in order to provide an optimal environment for viral replication; however, the mechanisms involved are not well understood. We have shown that the Epstein-Barr virus BORF2 protein and its homologue in herpes simplex virus 1 both induce G1/S, and do this by similar mechanisms which involve binding p53 and APOBEC3B and induction of p53. Our study identifies a new mechanism by which G1/S arrest can be induced in herpesvirus lytic infection and a new role of APOBEC3B in herpesvirus lytic infection.
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9
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USP7 regulates the ERK1/2 signaling pathway through deubiquitinating Raf-1 in lung adenocarcinoma. Cell Death Dis 2022; 13:698. [PMID: 35948545 PMCID: PMC9365811 DOI: 10.1038/s41419-022-05136-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 07/25/2022] [Accepted: 07/26/2022] [Indexed: 01/21/2023]
Abstract
Ubiquitin-specific protease 7 (USP7) is one of the deubiquitinating enzymes (DUBs) in the ubiquitin-specific protease (USP) family. It is a key regulator of numerous cellular functions including immune response, cell cycle, DNA damage and repair, epigenetics, and several signaling pathways. USP7 acts by removing ubiquitin from the substrate proteins. USP7 also binds to a specific binding motif of substrate proteins having the [P/A/E]-X-X-S or K-X-X-X-K protein sequences. To date, numerous substrate proteins of USP7 have been identified, but no studies have been conducted using the binding motif that USP7 binds. In the current study, we analyzed putative substrate proteins of USP7 through the [P/A/E]-X-X-S and K-X-X-X-K binding motifs using bioinformatics tools, and confirmed that Raf-1 is one of the substrates for USP7. USP7 binds to the Pro-Val-Asp-Ser (PVDS) motif of the conserved region 2 (CR2) which contains phosphorylation sites of Raf-1 and decreased M1-, K6-, K11-, K27-, K33-, and K48-linked polyubiquitination of Raf-1. We further identified that the DUB activity of USP7 decreases the threonine phosphorylation level of Raf-1 and inhibits signaling transduction through Raf activation. This regulatory mechanism inhibits the activation of the ERK1/2 signaling pathway, thereby inhibiting the G2/M transition and the cell proliferation of lung adenocarcinoma cells. In summary, our results indicate that USP7 deubiquitinates Raf-1 and is a new regulator of the ERK1/2 signaling pathway in lung adenocarcinoma.
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10
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Proteomic analysis reveals USP7 as a novel regulator of palmitic acid-induced hepatocellular carcinoma cell death. Cell Death Dis 2022; 13:563. [PMID: 35732625 PMCID: PMC9217975 DOI: 10.1038/s41419-022-05003-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 06/03/2022] [Accepted: 06/07/2022] [Indexed: 01/21/2023]
Abstract
Nutrient surplus and consequent free fatty acid accumulation in the liver cause hepatosteatosis. The exposure of free fatty acids to cultured hepatocyte and hepatocellular carcinoma cell lines induces cellular stress, organelle adaptation, and subsequent cell death. Despite many studies, the mechanism associated with lipotoxicity and subsequent cell death still remains poorly understood. Here, we have used the proteomics approach to circumvent the mechanism for lipotoxicity using hepatocellular carcinoma cells as a model. Our quantitative proteomics data revealed that ectopic lipids accumulation in cells severely affects the ubiquitin-proteasomal system. The palmitic acid (PA) partially lowered the expression of deubiquitinating enzyme USP7 which subsequently destabilizes p53 and promotes mitotic entry of cells. Our global phosphoproteomics analysis also provides strong evidence of an altered cell cycle checkpoint proteins' expression that abrogates early G2/M checkpoints recovery with damaged DNA and induced mitotic catastrophe leading to hepatocyte death. We observe that palmitic acid prefers apoptosis-inducing factor (AIF) mediated cell death by depolarizing mitochondria and translocating AIF to the nucleus. In summary, the present study provides evidence of PA-induced hepatocellular death mediated by deubiquitinase USP7 downregulation and subsequent mitotic catastrophe.
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11
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Epstein-Barr Virus BGLF2 commandeers RISC to interfere with cellular miRNA function. PLoS Pathog 2022; 18:e1010235. [PMID: 35007297 PMCID: PMC8782528 DOI: 10.1371/journal.ppat.1010235] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 01/21/2022] [Accepted: 12/27/2021] [Indexed: 01/27/2023] Open
Abstract
The Epstein-Barr virus (EBV) BGLF2 protein is a tegument protein with multiple effects on the cellular environment, including induction of SUMOylation of cellular proteins. Using affinity-purification coupled to mass-spectrometry, we identified the miRNA-Induced Silencing Complex (RISC), essential for miRNA function, as a top interactor of BGLF2. We confirmed BGLF2 interaction with the Ago2 and TNRC6 components of RISC in multiple cell lines and their co-localization in cytoplasmic bodies that also contain the stress granule marker G3BP1. In addition, BGLF2 expression led to the loss of processing bodies in multiple cell types, suggesting disruption of RISC function in mRNA regulation. Consistent with this observation, BGLF2 disrupted Ago2 association with multiple miRNAs. Using let-7 miRNAs as a model, we tested the hypothesis that BGLF2 interfered with the function of RISC in miRNA-mediated mRNA silencing. Using multiple reporter constructs with 3’UTRs containing let-7a regulated sites, we showed that BGLF2 inhibited let-7a miRNA activity dependent on these 3’UTRs, including those from SUMO transcripts which are known to be regulated by let-7 miRNAs. In keeping with these results, we showed that BGLF2 increased the cellular level of unconjugated SUMO proteins without affecting the level of SUMO transcripts. Such an increase in free SUMO is known to drive SUMOylation and would account for the effect of BGLF2 in inducing SUMOylation. We further showed that BGLF2 expression inhibited the loading of let-7 miRNAs into Ago2 proteins, and conversely, that lytic infection with EBV lacking BGLF2 resulted in increased interaction of let-7a and SUMO transcripts with Ago2, relative to WT EBV infection. Therefore, we have identified a novel role for BGLF2 as a miRNA regulator and shown that one outcome of this activity is the dysregulation of SUMO transcripts that leads to increased levels of free SUMO proteins and SUMOylation. Epstein-Barr virus (EBV) infects most people worldwide, persists for life and is associated with several kinds of cancer. In order to undergo efficient lytic infection, EBV must manipulate multiple cellular pathways. BGLF2 is an EBV lytic protein known to modulate several cellular processes including increasing the modification of cellular proteins with the Small Ubiquitin-Like Modifier (SUMO), a process referred to as SUMOylation. Here we show for the first time that BGLF2 interacts with a cellular complex (RISC) required for miRNA function and interferes with the function of some cellular miRNAs by sequestering this complex. One of the consequences of this effect is the increased expression of SUMO proteins, due to inhibition of the miRNAs that normally downregulate their expression. The resulting increase in SUMO proteins drives SUMOylation, providing a mechanism for the previously reported BGLF2-induced SUMOylation of cellular proteins. In addition, the discovery of BGLF2 as a miRNA regulator suggests that this EBV protein can control many cellular pathways by interfering with cellular miRNAs that normally regulate them.
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12
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Wilson P, Abdelmoti L, Norcross R, Jang ER, Palayam M, Galperin E. The role of USP7 in the Shoc2-ERK1/2 signaling axis and Noonan-like syndrome with loose anagen hair. J Cell Sci 2021; 134:272259. [PMID: 34553755 DOI: 10.1242/jcs.258922] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 09/09/2021] [Indexed: 01/04/2023] Open
Abstract
The ERK1/2 (also known as MAPK3 and MAPK1, respectively) signaling pathway is critical in organismal development and tissue morphogenesis. Deregulation of this pathway leads to congenital abnormalities with severe developmental dysmorphisms. The core ERK1/2 cascade relies on scaffold proteins, such as Shoc2 to guide and fine-tune its signals. Mutations in SHOC2 lead to the development of the pathology termed Noonan-like Syndrome with Loose Anagen Hair (NSLAH). However, the mechanisms underlying the functions of Shoc2 and its contributions to disease progression remain unclear. Here, we show that ERK1/2 pathway activation triggers the interaction of Shoc2 with the ubiquitin-specific protease USP7. We reveal that, in the Shoc2 module, USP7 functions as a molecular 'switch' that controls the E3 ligase HUWE1 and the HUWE1-induced regulatory feedback loop. We also demonstrate that disruption of Shoc2-USP7 binding leads to aberrant activation of the Shoc2-ERK1/2 axis. Importantly, our studies reveal a possible role for USP7 in the pathogenic mechanisms underlying NSLAH, thereby extending our understanding of how ubiquitin-specific proteases regulate intracellular signaling.
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Affiliation(s)
- Patricia Wilson
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY 40536, USA
| | - Lina Abdelmoti
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY 40536, USA
| | - Rebecca Norcross
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY 40536, USA
| | - Eun Ryoung Jang
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY 40536, USA
| | - Malathy Palayam
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY 40536, USA
| | - Emilia Galperin
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY 40536, USA
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13
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Coordinating DNA Replication and Mitosis through Ubiquitin/SUMO and CDK1. Int J Mol Sci 2021; 22:ijms22168796. [PMID: 34445496 PMCID: PMC8395760 DOI: 10.3390/ijms22168796] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 08/11/2021] [Accepted: 08/12/2021] [Indexed: 12/30/2022] Open
Abstract
Post-translational modification of the DNA replication machinery by ubiquitin and SUMO plays key roles in the faithful duplication of the genetic information. Among other functions, ubiquitination and SUMOylation serve as signals for the extraction of factors from chromatin by the AAA ATPase VCP. In addition to the regulation of DNA replication initiation and elongation, we now know that ubiquitination mediates the disassembly of the replisome after DNA replication termination, a process that is essential to preserve genomic stability. Here, we review the recent evidence showing how active DNA replication restricts replisome ubiquitination to prevent the premature disassembly of the DNA replication machinery. Ubiquitination also mediates the removal of the replisome to allow DNA repair. Further, we discuss the interplay between ubiquitin-mediated replisome disassembly and the activation of CDK1 that is required to set up the transition from the S phase to mitosis. We propose the existence of a ubiquitin–CDK1 relay, where the disassembly of terminated replisomes increases CDK1 activity that, in turn, favors the ubiquitination and disassembly of more replisomes. This model has important implications for the mechanism of action of cancer therapies that induce the untimely activation of CDK1, thereby triggering premature replisome disassembly and DNA damage.
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14
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Galarreta A, Valledor P, Ubieto‐Capella P, Lafarga V, Zarzuela E, Muñoz J, Malumbres M, Lecona E, Fernandez‐Capetillo O. USP7 limits CDK1 activity throughout the cell cycle. EMBO J 2021; 40:e99692. [PMID: 33856059 PMCID: PMC8167359 DOI: 10.15252/embj.201899692] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 03/04/2021] [Accepted: 03/09/2021] [Indexed: 01/18/2023] Open
Abstract
Chemical inhibitors of the deubiquitinase USP7 are currently being developed as anticancer agents based on their capacity to stabilize P53. Regardless of this activity, USP7 inhibitors also generate DNA damage in a p53-independent manner. However, the mechanism of this genotoxicity and its contribution to the anticancer effects of USP7 inhibitors are still under debate. Here we show that, surprisingly, even if USP7 inhibitors stop DNA replication, they also induce a widespread activation of CDK1 throughout the cell cycle, which leads to DNA damage and is toxic for mammalian cells. In addition, USP7 interacts with the phosphatase PP2A and supports its active localization in the cytoplasm. Accordingly, inhibition of USP7 or PP2A triggers very similar changes of the phosphoproteome, including a widespread increase in the phosphorylation of CDK1 targets. Importantly, the toxicity of USP7 inhibitors is alleviated by lowering CDK1 activity or by chemical activation of PP2A. Our work reveals that USP7 limits CDK1 activity at all cell cycle stages, providing a novel mechanism that explains the toxicity of USP7 inhibitors through untimely activation of CDK1.
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Affiliation(s)
- Antonio Galarreta
- Genomic Instability GroupSpanish National Cancer Research Centre (CNIO)MadridSpain
| | - Pablo Valledor
- Genomic Instability GroupSpanish National Cancer Research Centre (CNIO)MadridSpain
| | - Patricia Ubieto‐Capella
- Genomic Instability GroupSpanish National Cancer Research Centre (CNIO)MadridSpain
- Present address:
DNA Replication GroupSpanish National Cancer Research Centre (CNIO)MadridSpain
| | - Vanesa Lafarga
- Genomic Instability GroupSpanish National Cancer Research Centre (CNIO)MadridSpain
| | - Eduardo Zarzuela
- Proteomics UnitSpanish National Cancer Research Centre (CNIO) and ProteoRed‐ISCIIIMadridSpain
| | - Javier Muñoz
- Proteomics UnitSpanish National Cancer Research Centre (CNIO) and ProteoRed‐ISCIIIMadridSpain
| | - Marcos Malumbres
- Cell Division and Cancer GroupSpanish National Cancer Research Centre (CNIO)MadridSpain
| | - Emilio Lecona
- Chromatin, Cancer and the Ubiquitin System labCentre for Molecular Biology Severo Ochoa (CBMSO)MadridSpain
| | - Oscar Fernandez‐Capetillo
- Genomic Instability GroupSpanish National Cancer Research Centre (CNIO)MadridSpain
- Science for Life LaboratoryDivision of Genome BiologyDepartment of Medical Biochemistry and BiophysicsKarolinska InstituteStockholmSweden
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15
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Su D, Wang W, Hou Y, Wang L, Yi X, Cao C, Wang Y, Gao H, Wang Y, Yang C, Liu B, Chen X, Wu X, Wu J, Yan D, Wei S, Han L, Liu S, Wang Q, Shi L, Shan L. Bimodal regulation of the PRC2 complex by USP7 underlies tumorigenesis. Nucleic Acids Res 2021; 49:4421-4440. [PMID: 33849069 PMCID: PMC8096222 DOI: 10.1093/nar/gkab209] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 04/01/2021] [Indexed: 12/27/2022] Open
Abstract
Although overexpression of EZH2, a catalytic subunit of the polycomb repressive complex 2 (PRC2), is an eminent feature of various cancers, the regulation of its abundance and function remains insufficiently understood. We report here that the PRC2 complex is physically associated with ubiquitin-specific protease USP7 in cancer cells where USP7 acts to deubiquitinate and stabilize EZH2. Interestingly, we found that USP7-catalyzed H2BK120ub1 deubiquitination is a prerequisite for chromatin loading of PRC2 thus H3K27 trimethylation, and this process is not affected by H2AK119 ubiquitination catalyzed by PRC1. Genome-wide analysis of the transcriptional targets of the USP7/PRC2 complex identified a cohort of genes including FOXO1 that are involved in cell growth and proliferation. We demonstrated that the USP7/PRC2 complex drives cancer cell proliferation and tumorigenesis in vitro and in vivo. We showed that the expression of both USP7 and EZH2 elevates during tumor progression, corresponding to a diminished FOXO1 expression, and the level of the expression of USP7 and EZH2 strongly correlates with histological grades and prognosis of tumor patients. These results reveal a dual role for USP7 in the regulation of the abundance and function of EZH2, supporting the pursuit of USP7 as a therapeutic target for cancer intervention.
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Affiliation(s)
- Dongxue Su
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China.,State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Signaling Network, School of Life Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Wenjuan Wang
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Yongqiang Hou
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Signaling Network, School of Life Sciences, Xiamen University, Xiamen, Fujian 361102, China.,Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China
| | - Liyong Wang
- Core Facilities for Molecular Biology, Capital Medical University, Beijing 100069, China
| | - Xianfu Yi
- School of Biomedical Engineering, Tianjin Medical University, Tianjin 300070, China
| | - Cheng Cao
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China
| | - Yuejiao Wang
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China
| | - Huan Gao
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Signaling Network, School of Life Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Yue Wang
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Chao Yang
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Beibei Liu
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Xing Chen
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Xiaodi Wu
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Jiajing Wu
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Dong Yan
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Shuqi Wei
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Lulu Han
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Shumeng Liu
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Qian Wang
- Tianjin Medical University Cancer Institute and Hospital, Tianjin Key Laboratory of Cancer Prevention and Therapy, National Clinical Research Center for Cancer, Tianjin 300060, China
| | - Lei Shi
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China
| | - Lin Shan
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
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16
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Fan Y, Köberlin MS, Ratnayeke N, Liu C, Deshpande M, Gerhardt J, Meyer T. LRR1-mediated replisome disassembly promotes DNA replication by recycling replisome components. J Cell Biol 2021; 220:212186. [PMID: 34037657 PMCID: PMC8160578 DOI: 10.1083/jcb.202009147] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 03/30/2021] [Accepted: 05/04/2021] [Indexed: 11/22/2022] Open
Abstract
After two converging DNA replication forks meet, active replisomes are disassembled and unloaded from chromatin. A key process in replisome disassembly is the unloading of CMG helicases (CDC45–MCM–GINS), which is initiated in Caenorhabditis elegans and Xenopus laevis by the E3 ubiquitin ligase CRL2LRR1. Here, we show that human cells lacking LRR1 fail to unload CMG helicases and accumulate increasing amounts of chromatin-bound replisome components as cells progress through S phase. Markedly, we demonstrate that the failure to disassemble replisomes reduces the rate of DNA replication increasingly throughout S phase by sequestering rate-limiting replisome components on chromatin and blocking their recycling. Continued binding of CMG helicases to chromatin during G2 phase blocks mitosis by activating an ATR-mediated G2/M checkpoint. Finally, we provide evidence that LRR1 is an essential gene for human cell division, suggesting that CRL2LRR1 enzyme activity is required for the proliferation of cancer cells and is thus a potential target for cancer therapy.
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Affiliation(s)
- Yilin Fan
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA.,Department of Cell and Developmental Biology, Weill Cornell Medicine, New York, NY
| | - Marielle S Köberlin
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA
| | - Nalin Ratnayeke
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA.,Department of Cell and Developmental Biology, Weill Cornell Medicine, New York, NY
| | - Chad Liu
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA
| | - Madhura Deshpande
- Ronald O. Perelman and Claudia Cohen Center for Reproductive Medicine, Weill Cornell Medicine, New York, NY
| | - Jeannine Gerhardt
- Ronald O. Perelman and Claudia Cohen Center for Reproductive Medicine, Weill Cornell Medicine, New York, NY.,Department of Obstetrics and Gynecology, Weill Cornell Medicine, New York, NY
| | - Tobias Meyer
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA.,Department of Cell and Developmental Biology, Weill Cornell Medicine, New York, NY
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17
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Pawlak A, Bajzert J, Bugiel K, Hernández Suárez B, Kutkowska J, Rapak A, Hildebrand W, Obmińska-Mrukowicz B, Freire R, Smits VAJ. Ubiquitin-specific protease 7 as a potential therapeutic target in dogs with hematopoietic malignancies. J Vet Intern Med 2021; 35:1041-1051. [PMID: 33650720 PMCID: PMC7995420 DOI: 10.1111/jvim.16082] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 02/03/2021] [Accepted: 02/04/2021] [Indexed: 12/13/2022] Open
Abstract
Background Ubiquitin‐specific protease 7 (USP7) belongs to the group of deubiquitinating enzymes (DUBs), which remove ubiquitin which controls various cellular processes such as chromosome segregation, DNA repair, gene expression, protein localization, kinase activity, protein degradation, cell cycle progression, and apoptosis. It is critical for several important functions in the cell, and therefore dysregulation of USP7 can contribute to tumorigenesis. Objectives Alterations in the USP7 protein have been identified in various malignancies of humans. Our aim was to examine whether USP7 could be a potential therapeutic target in hematopoietic cancers of dogs. Methods The expression level of USP7 in lymphocytes from healthy dogs and canine lymphoma cells was determined, and the effect of USP7 inhibition on the vital functions of canine cancer cells was examined. Results We showed that USP7 was overexpressed in lymphomas in dogs. The USP7 inhibitor P5091 has selective cytotoxic activity in canine lymphoma and leukemia cell lines. Our results indicate that inhibition of USP7 leads to a disruption of cell cycle progression, and triggers DNA damage and apoptosis. The observed proapoptotic effect of the USP7 inhibitor most likely is not dependent on the p53 pathway. Conclusions and Clinical Importance Our results suggest that USP7 could be explored as a potential therapeutic target in dogs with lymphoma. The effectiveness of USP7 inhibition in malignant cells is predicted to be independent of their p53 status.
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Affiliation(s)
- Aleksandra Pawlak
- Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences, Wroclaw, Poland
| | - Joanna Bajzert
- Department of Immunology, Pathophysiology and Veterinary Preventive Medicine, Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences, Wroclaw, Poland
| | - Katarzyna Bugiel
- Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences, Wroclaw, Poland
| | - Beatriz Hernández Suárez
- Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences, Wroclaw, Poland
| | - Justyna Kutkowska
- Laboratory of Tumor Molecular Immunobiology, Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Poland
| | - Andrzej Rapak
- Laboratory of Tumor Molecular Immunobiology, Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Poland
| | | | - Bożena Obmińska-Mrukowicz
- Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences, Wroclaw, Poland
| | - Raimundo Freire
- Unidad de Investigación, Hospital Universitario de Canarias, FIISC, La Laguna, Tenerife, Spain.,Instituto de Tecnologías Biomédicas, Universidad de La Laguna, Tenerife, Spain.,Universidad Fernando Pessoa Canarias, Las Palmas de Gran Canaria, Spain
| | - Veronique A J Smits
- Unidad de Investigación, Hospital Universitario de Canarias, FIISC, La Laguna, Tenerife, Spain.,Instituto de Tecnologías Biomédicas, Universidad de La Laguna, Tenerife, Spain.,Universidad Fernando Pessoa Canarias, Las Palmas de Gran Canaria, Spain
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18
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Ashton NW, Valles GJ, Jaiswal N, Bezsonova I, Woodgate R. DNA Polymerase ι Interacts with Both the TRAF-like and UBL1-2 Domains of USP7. J Mol Biol 2021; 433:166733. [PMID: 33279577 PMCID: PMC7873624 DOI: 10.1016/j.jmb.2020.166733] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 11/20/2020] [Accepted: 11/30/2020] [Indexed: 12/12/2022]
Abstract
Reversible protein ubiquitination is an essential signaling mechanism within eukaryotes. Deubiquitinating enzymes are critical to this process, as they mediate removal of ubiquitin from substrate proteins. Ubiquitin-specific protease 7 (USP7) is a prominent deubiquitinating enzyme, with an extensive network of interacting partners and established roles in cell cycle activation, immune responses and DNA replication. Characterized USP7 substrates primarily interact with one of two major binding sites outside the catalytic domain. These are located on the USP7 N-terminal TRAF-like (TRAF) domain and the first and second UBL domains (UBL1-2) within the C-terminal tail. Here, we report that DNA polymerase iota (Pol ι) is a novel USP7 substrate that interacts with both TRAF and UBL1-2. Through the use of biophysical approaches and mutational analysis, we characterize both interfaces and demonstrate that bipartite binding to both USP7 domains is required for efficient Pol ι deubiquitination. Together, these data establish a new bipartite mode of USP7 substrate binding.
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Affiliation(s)
- Nicholas W Ashton
- Laboratory of Genomic Integrity, National Institute of Child Health and Human Development, National Institutes of Health, 9800 Medical Center Drive, Bethesda, MD 20892-3371, USA.
| | - Gabrielle J Valles
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, CT 06030, USA.
| | - Nancy Jaiswal
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, CT 06030, USA.
| | - Irina Bezsonova
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, CT 06030, USA.
| | - Roger Woodgate
- Laboratory of Genomic Integrity, National Institute of Child Health and Human Development, National Institutes of Health, 9800 Medical Center Drive, Bethesda, MD 20892-3371, USA.
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19
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Molecular Mechanisms of DUBs Regulation in Signaling and Disease. Int J Mol Sci 2021; 22:ijms22030986. [PMID: 33498168 PMCID: PMC7863924 DOI: 10.3390/ijms22030986] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/15/2021] [Accepted: 01/18/2021] [Indexed: 02/07/2023] Open
Abstract
The large family of deubiquitinating enzymes (DUBs) are involved in the regulation of a plethora of processes carried out inside the cell by protein ubiquitination. Ubiquitination is a basic pathway responsible for the correct protein homeostasis in the cell, which could regulate the fate of proteins through the ubiquitin–proteasome system (UPS). In this review we will focus on recent advances on the molecular mechanisms and specificities found for some types of DUBs enzymes, highlighting illustrative examples in which the regulatory mechanism for DUBs has been understood in depth at the molecular level by structural biology. DUB proteases are responsible for cleavage and regulation of the multiple types of ubiquitin linkages that can be synthesized inside the cell, known as the ubiquitin-code, which are tightly connected to specific substrate functions. We will display some strategies carried out by members of different DUB families to provide specificity on the cleavage of particular ubiquitin linkages. Finally, we will also discuss recent progress made for the development of drug compounds targeting DUB proteases, which are usually correlated to the progress of many pathologies such as cancer and neurodegenerative diseases.
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20
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Bojagora A, Saridakis V. USP7 manipulation by viral proteins. Virus Res 2020; 286:198076. [DOI: 10.1016/j.virusres.2020.198076] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Revised: 05/14/2020] [Accepted: 06/24/2020] [Indexed: 01/27/2023]
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21
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Valles GJ, Bezsonova I, Woodgate R, Ashton NW. USP7 Is a Master Regulator of Genome Stability. Front Cell Dev Biol 2020; 8:717. [PMID: 32850836 PMCID: PMC7419626 DOI: 10.3389/fcell.2020.00717] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 07/13/2020] [Indexed: 12/25/2022] Open
Abstract
Genetic alterations, including DNA mutations and chromosomal abnormalities, are primary drivers of tumor formation and cancer progression. These alterations can endow cells with a selective growth advantage, enabling cancers to evade cell death, proliferation limits, and immune checkpoints, to metastasize throughout the body. Genetic alterations occur due to failures of the genome stability pathways. In many cancers, the rate of alteration is further accelerated by the deregulation of these processes. The deubiquitinating enzyme ubiquitin specific protease 7 (USP7) has recently emerged as a key regulator of ubiquitination in the genome stability pathways. USP7 is also deregulated in many cancer types, where deviances in USP7 protein levels are correlated with cancer progression. In this work, we review the increasingly evident role of USP7 in maintaining genome stability, the links between USP7 deregulation and cancer progression, as well as the rationale of targeting USP7 in cancer therapy.
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Affiliation(s)
- Gabrielle J Valles
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, CT, United States
| | - Irina Bezsonova
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, CT, United States
| | - Roger Woodgate
- Laboratory of Genomic Integrity, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
| | - Nicholas W Ashton
- Laboratory of Genomic Integrity, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
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22
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Kim JM, Yang YS, Park KH, Ge X, Xu R, Li N, Song M, Chun H, Bok S, Charles JF, Filhol-Cochet O, Boldyreff B, Dinter T, Yu PB, Kon N, Gu W, Takarada T, Greenblatt MB, Shim JH. A RUNX2 stabilization pathway mediates physiologic and pathologic bone formation. Nat Commun 2020; 11:2289. [PMID: 32385263 PMCID: PMC7210266 DOI: 10.1038/s41467-020-16038-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Accepted: 04/10/2020] [Indexed: 12/21/2022] Open
Abstract
The osteoblast differentiation capacity of skeletal stem cells (SSCs) must be tightly regulated, as inadequate bone formation results in low bone mass and skeletal fragility, and over-exuberant osteogenesis results in heterotopic ossification (HO) of soft tissues. RUNX2 is essential for tuning this balance, but the mechanisms of posttranslational control of RUNX2 remain to be fully elucidated. Here, we identify that a CK2/HAUSP pathway is a key regulator of RUNX2 stability, as Casein kinase 2 (CK2) phosphorylates RUNX2, recruiting the deubiquitinase herpesvirus-associated ubiquitin-specific protease (HAUSP), which stabilizes RUNX2 by diverting it away from ubiquitin-dependent proteasomal degradation. This pathway is important for both the commitment of SSCs to osteoprogenitors and their subsequent maturation. This CK2/HAUSP/RUNX2 pathway is also necessary for HO, as its inhibition blocked HO in multiple models. Collectively, active deubiquitination of RUNX2 is required for bone formation and this CK2/HAUSP deubiquitination pathway offers therapeutic opportunities for disorders of inappropriate mineralization.
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Affiliation(s)
- Jung-Min Kim
- Department of Medicine, University of Massachusetts Medical School, Worcester, MA, USA
| | - Yeon-Suk Yang
- Department of Medicine, University of Massachusetts Medical School, Worcester, MA, USA
| | - Kwang Hwan Park
- Department of Orthopaedic Surgery, Yonsei University College of Medicine, Seoul, South Korea
| | - Xianpeng Ge
- Department of Medicine, University of Massachusetts Medical School, Worcester, MA, USA
| | - Ren Xu
- State Key Laboratory of Cellular Stress Biology, Xiamen University, Fujian, China
| | - Na Li
- State Key Laboratory of Cellular Stress Biology, Xiamen University, Fujian, China
| | - Minkyung Song
- Department of integrative biotechnology, Sungkyunkwan University, Suwon, South Korea
| | - Hyunho Chun
- Department of Mathematical Sciences, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Seoyeon Bok
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY, USA
| | - Julia F Charles
- Department of Orthopedics and Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Odile Filhol-Cochet
- INSERM U1036, pour le Vivant/Biologie du Cancer et de l'Infection, Commissariat à l'Énergie Atomique et aux Énerigies Alternatives Grenoble, Grenoble, France
| | | | - Teresa Dinter
- Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Paul B Yu
- Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Ning Kon
- Institute of Cancer Genetics, College of Physicians and Surgeons of Columbia University, New York, NY, USA
| | - Wei Gu
- Institute of Cancer Genetics, College of Physicians and Surgeons of Columbia University, New York, NY, USA
- Department of Pathology and Cell Biology, College of Physicians and Surgeons of Columbia University, New York, NY, USA
| | - Takeshi Takarada
- Department of Regenerative Science, Okayama University Graduate School of Medicine, Okayama, Japan
| | - Matthew B Greenblatt
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY, USA.
| | - Jae-Hyuck Shim
- Department of Medicine, University of Massachusetts Medical School, Worcester, MA, USA.
- Li Weibo Institute for Rare Diseases Research, University of Massachusetts Medical School, Worcester, MA, USA.
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23
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The Ubiquitin-Specific Protease Usp7, a Novel Merkel Cell Polyomavirus Large T-Antigen Interaction Partner, Modulates Viral DNA Replication. J Virol 2020; 94:JVI.01638-19. [PMID: 31801860 DOI: 10.1128/jvi.01638-19] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 12/01/2019] [Indexed: 02/06/2023] Open
Abstract
Merkel cell polyomavirus (MCPyV) is the major cause for Merkel cell carcinoma (MCC), a rare but highly aggressive skin cancer predominantly found in elderly and immunosuppressed patients. The early viral gene products large T-antigen (LT) and small T-antigen (sT) are important for efficient viral DNA replication, and both contribute to transformation processes. These functions are executed mainly through interactions with host factors. Here, we identify the cellular ubiquitin-specific processing protease 7 (Usp7) as a new interaction partner of the MCPyV LT. Using glutathione S-transferase pulldown experiments, we show that MCPyV LT directly binds to Usp7 and that N- as well as C-terminal regions of LT bind to the TRAF (tumor necrosis factor receptor-associated) domain of Usp7. We demonstrate that endogenous Usp7 coprecipitates with MCPyV T-antigens and relocalizes to viral DNA replication centers in cells actively replicating MCPyV genomes. We show that Usp7 does not alter ubiquitination levels of the T-antigens; however, Usp7 binding increases the binding affinity of LT to the origin of replication, thereby negatively regulating viral DNA replication. Together, these data identify Usp7 as a restriction factor of MCPyV replication. In contrast to other DNA viruses, Usp7 does not affect MCPyV gene expression via its ubiquitination activity but influences MCPyV DNA replication solely via a novel mechanism that modulates binding of LT to viral DNA.IMPORTANCE MCPyV is the only human polyomavirus that is associated with cancer; the majority of Merkel cell cancers have a viral etiology. While much emphasis was placed on investigations to understand the transformation process by MCPyV oncoproteins and cellular factors, we have only limited knowledge of cellular factors participating in the MCPyV life cycle. Here, we describe Usp7, a cellular deubiquitination enzyme, as a new factor involved in MCPyV replication. Usp7 is known in the context of large DNA tumor viruses, Epstein-Barr virus (EBV) and Kaposi's sarcoma herpesvirus, to restrict viral replication. Similar to EBV, where Usp7 binding to EBNA1 increases EBNA1 binding affinity to viral DNA, we find MCPyV LT binding to the origin of replication to be increased in the presence of Usp7, resulting in restriction of viral DNA replication. However, Usp7-induced restriction of MCPyV replication is independent of its enzymatic activity, thereby constituting a novel mechanism of Usp7-induced restriction of viral replication.
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24
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Gagarina V, Bojagora A, Lacdao IK, Luthra N, Pfoh R, Mohseni S, Chaharlangi D, Tan N, Saridakis V. Structural Basis of the Interaction Between Ubiquitin Specific Protease 7 and Enhancer of Zeste Homolog 2. J Mol Biol 2019; 432:897-912. [PMID: 31866294 DOI: 10.1016/j.jmb.2019.12.026] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 11/26/2019] [Accepted: 12/12/2019] [Indexed: 11/25/2022]
Abstract
USP7 is a deubiquitinase that regulates many diverse cellular processes, including tumor suppression, epigenetics, and genome stability. Several substrates, including GMPS, UHRF1, and ICP0, were shown to bear a specific KxxxK motif that interacts within the C-terminal region of USP7. We identified a similar motif in Enhancer of Zeste 2 (EZH2), the histone methyltransferase found within Polycomb Repressive Complex 2 (PRC2). PRC2 is responsible for the methylation of Histone 3 Lys27 (H3K27) leading to gene silencing. GST pull-down and coimmunoprecipitation experiments showed that USP7 interacts with EZH2. We determined the structural basis of interaction between USP7 and EZH2 and identified residues mediating the interaction. Mutations in these critical residues disrupted the interaction between USP7 and EZH2. Furthermore, USP7 silencing and knockout experiments showed decreased EZH2 levels in HCT116 carcinoma cells. Finally, we demonstrated decreased H3K27Me3 levels in HCT116 USP7 knockout cells. These results indicate that USP7 interacts with EZH2 and regulates both its stability and function.
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Affiliation(s)
- Varvara Gagarina
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario, M3J1P3, Canada
| | - Anna Bojagora
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario, M3J1P3, Canada
| | - Ira Kay Lacdao
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario, M3J1P3, Canada
| | - Niharika Luthra
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario, M3J1P3, Canada
| | - Roland Pfoh
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario, M3J1P3, Canada
| | - Sadaf Mohseni
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario, M3J1P3, Canada
| | - Danica Chaharlangi
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario, M3J1P3, Canada
| | - Nadine Tan
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario, M3J1P3, Canada
| | - Vivian Saridakis
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario, M3J1P3, Canada.
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25
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González‐Arzola K, Velázquez‐Cruz A, Guerra‐Castellano A, Casado‐Combreras MÁ, Pérez‐Mejías G, Díaz‐Quintana A, Díaz‐Moreno I, De la Rosa MÁ. New moonlighting functions of mitochondrial cytochromecin the cytoplasm and nucleus. FEBS Lett 2019; 593:3101-3119. [DOI: 10.1002/1873-3468.13655] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 10/13/2019] [Accepted: 10/15/2019] [Indexed: 12/30/2022]
Affiliation(s)
- Katiuska González‐Arzola
- Institute for Chemical Research (IIQ) Scientific Research Centre Isla de la Cartuja (cicCartuja) University of Seville‐CSIC Spain
| | - Alejandro Velázquez‐Cruz
- Institute for Chemical Research (IIQ) Scientific Research Centre Isla de la Cartuja (cicCartuja) University of Seville‐CSIC Spain
| | - Alejandra Guerra‐Castellano
- Institute for Chemical Research (IIQ) Scientific Research Centre Isla de la Cartuja (cicCartuja) University of Seville‐CSIC Spain
| | - Miguel Á. Casado‐Combreras
- Institute for Chemical Research (IIQ) Scientific Research Centre Isla de la Cartuja (cicCartuja) University of Seville‐CSIC Spain
| | - Gonzalo Pérez‐Mejías
- Institute for Chemical Research (IIQ) Scientific Research Centre Isla de la Cartuja (cicCartuja) University of Seville‐CSIC Spain
| | - Antonio Díaz‐Quintana
- Institute for Chemical Research (IIQ) Scientific Research Centre Isla de la Cartuja (cicCartuja) University of Seville‐CSIC Spain
| | - Irene Díaz‐Moreno
- Institute for Chemical Research (IIQ) Scientific Research Centre Isla de la Cartuja (cicCartuja) University of Seville‐CSIC Spain
| | - Miguel Á. De la Rosa
- Institute for Chemical Research (IIQ) Scientific Research Centre Isla de la Cartuja (cicCartuja) University of Seville‐CSIC Spain
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26
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Zhang MJ, Chen DS, Li H, Liu WW, Han GY, Han YF. Clinical significance of USP7 and EZH2 in predicting prognosis of laryngeal squamous cell carcinoma and their possible functional mechanism. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2019; 12:2184-2194. [PMID: 31934041 PMCID: PMC6949638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 02/26/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND Laryngeal squamous cell carcinoma (LSCC) is one of the most prevalent cancer types in the world. The ubiquitin specific protease 7 (USP7), a kind of deubiquitylating enzyme, has been reported to play multifaceted roles in different tumor types. EZH2 has been found to be highly expressed in various malignantcells and high expression of EZH2 is closely related to tumor growth infiltration, lymph node involvement, clinical stage, and poor prognosis. The aim of this study was to investigate the expression and function of USP7 and EZH2 in LSCC. CASE PRESENTATION Immunohistochemical staining and histochemical staining were performed to explore the expression of USP7 and EZH2 in both LSCC tissues and adjacent normal laryngeal tissues. Chi-square test, univariate analysis, and multivariate analysis were conducted to statistically evaluate the clinical significance of USP7 and EZH2. CONCLUSIONS USP7and EZH2 affects LSCC evolution; USP7 and EZH2 were upregulated in LSCC tissues, which can serve as independent prognostic predictors, and potential therapeutic targets for LSCC.
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Affiliation(s)
- Ming-Jie Zhang
- Department of Otorhinolaryngology, The First Affiliated Hospital of Bengbu Medical University Bengbu, Anhui, China
| | - De-Shang Chen
- Department of Otorhinolaryngology, The First Affiliated Hospital of Bengbu Medical University Bengbu, Anhui, China
| | - Hui Li
- Department of Otorhinolaryngology, The First Affiliated Hospital of Bengbu Medical University Bengbu, Anhui, China
| | - Wei-Wei Liu
- Department of Otorhinolaryngology, The First Affiliated Hospital of Bengbu Medical University Bengbu, Anhui, China
| | - Guo-Ying Han
- Department of Otorhinolaryngology, The First Affiliated Hospital of Bengbu Medical University Bengbu, Anhui, China
| | - Yue-Feng Han
- Department of Otorhinolaryngology, The First Affiliated Hospital of Bengbu Medical University Bengbu, Anhui, China
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27
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Georges A, Coyaud E, Marcon E, Greenblatt J, Raught B, Frappier L. USP7 Regulates Cytokinesis through FBXO38 and KIF20B. Sci Rep 2019; 9:2724. [PMID: 30804394 PMCID: PMC6389929 DOI: 10.1038/s41598-019-39368-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 01/18/2019] [Indexed: 01/13/2023] Open
Abstract
The ubiquitin specific protease 7 (USP7 or HAUSP) is known to regulate a variety of cellular processes by binding and deubiquitylating specific target proteins. To gain a more comprehensive understanding of its interactions and functions, we used affinity purification coupled to mass spectrometry to profile USP7 interactions. This revealed a novel interaction with FBXO38, a poorly characterized F-box protein. We showed that USP7 stabilizes FBXO38 dependent on its catalytic activity by protecting FBXO38 from proteasomal degradation. We used a BioID approach to profile the protein interactions (and putative functions) of FBXO38, revealing an interaction with KIF20B, a Kinesin-6 protein required for efficient cytokinesis. FBXO38 was shown to function independently from an SCF complex to stabilize KIF20B. Consequently, depletion of either FBXO38 or USP7 led to dramatic decreases in KIF20B levels and KIF20B at the midbody, which were manifested in cytokinetic defects. Furthermore, cytokinetic defects associated with USP7 silencing were rescued by restoring FBXO38 or KIF20B. The results indicate a novel mechanism of regulating cytokinesis through USP7 and FBXO38.
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Affiliation(s)
- Anna Georges
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Etienne Coyaud
- The Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, M5G 1L7, Canada
| | - Edyta Marcon
- Donnelly Centre, University of Toronto, Toronto, Canada
| | - Jack Greenblatt
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada.,Donnelly Centre, University of Toronto, Toronto, Canada
| | - Brian Raught
- The Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, M5G 1L7, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
| | - Lori Frappier
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada.
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28
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USP7: Structure, substrate specificity, and inhibition. DNA Repair (Amst) 2019; 76:30-39. [PMID: 30807924 DOI: 10.1016/j.dnarep.2019.02.005] [Citation(s) in RCA: 95] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Revised: 02/07/2019] [Indexed: 12/24/2022]
Abstract
Turnover of cellular proteins is regulated by Ubiquitin Proteasome System (UPS). Components of this pathway, including the proteasome, ubiquitinating enzymes and deubiquitinating enzymes, are highly specialized and tightly regulated. In this mini-review we focus on the de-ubiquitinating enzyme USP7, and summarize latest advances in understanding its structure, substrate specificity and relevance to human cancers. There is increasing interest in UPS components as targets for cancer therapy and here we also overview the recent progress in the development of small molecule inhibitors that target USP7.
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29
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Cheng AZ, Yockteng-Melgar J, Jarvis MC, Malik-Soni N, Borozan I, Carpenter MA, McCann JL, Ebrahimi D, Shaban NM, Marcon E, Greenblatt J, Brown WL, Frappier L, Harris RS. Epstein-Barr virus BORF2 inhibits cellular APOBEC3B to preserve viral genome integrity. Nat Microbiol 2018; 4:78-88. [PMID: 30420783 PMCID: PMC6294688 DOI: 10.1038/s41564-018-0284-6] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 10/08/2018] [Indexed: 12/29/2022]
Abstract
The APOBEC family of single-stranded (ss)DNA cytosine deaminases provides innate immunity against virus and transposon replication1–4. A well-studied mechanism is APOBEC3G restriction of HIV-1, which is counteracted by a virus-encoded degradation mechanism1–4. Accordingly, most work has focused on retroviruses with obligate ssDNA replication intermediates and it is unclear whether large double-stranded (ds)DNA viruses may be similarly susceptible to restriction. Here, we show that the large dsDNA herpesvirus Epstein-Barr virus (EBV), which is the causative agent of infectious mononucleosis and multiple cancers5, utilizes a two-pronged approach to counteract restriction by APOBEC3B. The large subunit of the EBV ribonucleotide reductase, BORF26,7, bound to APOBEC3B in proteomics studies and immunoprecipitation experiments. Mutagenesis mapped the interaction to the APOBEC3B catalytic domain, and biochemical studies demonstrated that BORF2 stoichiometrically inhibits APOBEC3B DNA cytosine deaminase activity. BORF2 also caused a dramatic relocalization of nuclear APOBEC3B to perinuclear bodies. Upon lytic reactivation, BORF2-null viruses were susceptible to APOBEC3B-mediated deamination as evidenced by lower viral titers, lower infectivity, and hypermutation. The Kaposi’s sarcoma herpesvirus (KSHV) homolog, ORF61, also bound APOBEC3B and mediated relocalization. These data support a model in which the genomic integrity of human γ-herpesviruses is maintained by active neutralization of the antiviral enzyme APOBEC3B.
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Affiliation(s)
- Adam Z Cheng
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA.,Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA.,Institute for Molecular Virology, University of Minnesota, Minneapolis, MN, USA.,Center for Genome Engineering, University of Minnesota, Minneapolis, MN, USA
| | | | - Matthew C Jarvis
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA.,Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA.,Institute for Molecular Virology, University of Minnesota, Minneapolis, MN, USA.,Center for Genome Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Natasha Malik-Soni
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Ivan Borozan
- Ontario Institute for Cancer Research, MaRS Centre, Toronto, Ontario, Canada
| | - Michael A Carpenter
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA.,Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA.,Institute for Molecular Virology, University of Minnesota, Minneapolis, MN, USA.,Center for Genome Engineering, University of Minnesota, Minneapolis, MN, USA.,Howard Hughes Medical Institute, University of Minnesota, Minneapolis, MN, USA
| | - Jennifer L McCann
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA.,Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA.,Institute for Molecular Virology, University of Minnesota, Minneapolis, MN, USA.,Center for Genome Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Diako Ebrahimi
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA.,Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA.,Institute for Molecular Virology, University of Minnesota, Minneapolis, MN, USA.,Center for Genome Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Nadine M Shaban
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA.,Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA.,Institute for Molecular Virology, University of Minnesota, Minneapolis, MN, USA.,Center for Genome Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Edyta Marcon
- Donnelly Centre, University of Toronto, Toronto, Ontario, Canada
| | - Jack Greenblatt
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada.,Donnelly Centre, University of Toronto, Toronto, Ontario, Canada
| | - William L Brown
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA.,Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA.,Institute for Molecular Virology, University of Minnesota, Minneapolis, MN, USA.,Center for Genome Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Lori Frappier
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada.
| | - Reuben S Harris
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA. .,Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA. .,Institute for Molecular Virology, University of Minnesota, Minneapolis, MN, USA. .,Center for Genome Engineering, University of Minnesota, Minneapolis, MN, USA. .,Howard Hughes Medical Institute, University of Minnesota, Minneapolis, MN, USA.
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30
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Georges A, Marcon E, Greenblatt J, Frappier L. Identification and Characterization of USP7 Targets in Cancer Cells. Sci Rep 2018; 8:15833. [PMID: 30367141 PMCID: PMC6203733 DOI: 10.1038/s41598-018-34197-x] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 10/12/2018] [Indexed: 02/07/2023] Open
Abstract
The ubiquitin specific protease, USP7, regulates multiple cellular pathways relevant for cancer through its ability to bind and sometimes stabilize specific target proteins through deubiquitylation. To gain a more complete profile of USP7 interactions in cancer cells, we performed affinity purification coupled to mass spectrometry to identify USP7 binding targets in gastric carcinoma cells. This confirmed reported associations of USP7 with USP11, PPM1G phosphatase and TRIP12 E3 ubiquitin ligase as well as identifying novel interactions with two DEAD/DEAH-box RNA helicases, DDX24 and DHX40. Using USP7 binding pocket mutants, we show that USP11, PPM1G, TRIP12 and DDX24 bind USP7 through its TRAF domain binding pocket, while DHX40 interacts with USP7 through a distinct binding pocket in the Ubl2 domain. P/A/ExxS motifs in USP11 and DDX24 that are critical for USP7 binding were also identified. Modulation of USP7 expression levels and inhibition of USP7 catalytic activity in multiple cells lines showed that USP7 consistently stabilizes DDX24, DHX40 and TRIP12 dependent on its catalytic activity, while USP11 and PPM1G levels were not consistently affected. Our study better defines the mechanisms of USP7 interaction with known targets and identifies DDX24 and DHX40 as new targets that are specifically bound and regulated by USP7.
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Affiliation(s)
- Anna Georges
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Edyta Marcon
- Donnelly Centre, University of Toronto, Toronto, Canada
| | - Jack Greenblatt
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada.,Donnelly Centre, University of Toronto, Toronto, Canada
| | - Lori Frappier
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada.
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31
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Vishnoi M, Boral D, Liu H, Sprouse ML, Yin W, Goswami-Sewell D, Tetzlaff MT, Davies MA, Oliva ICG, Marchetti D. Targeting USP7 Identifies a Metastasis-Competent State within Bone Marrow-Resident Melanoma CTCs. Cancer Res 2018; 78:5349-5362. [PMID: 30026332 PMCID: PMC6139068 DOI: 10.1158/0008-5472.can-18-0644] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 06/12/2018] [Accepted: 07/13/2018] [Indexed: 02/03/2023]
Abstract
Systemic metastasis is the major cause of death from melanoma, the most lethal form of skin cancer. Although most patients with melanoma exhibit a substantial gap between onset of primary and metastatic tumors, signaling mechanisms implicated in the period of metastatic latency remain unclear. We hypothesized that melanoma circulating tumor cells (CTC) home to and reside in the bone marrow during the asymptomatic phase of disease progression. Using a strategy to deplete normal cell lineages (Lin-), we isolated CTC-enriched cell populations from the blood of patients with metastatic melanoma, verified by the presence of putative CTCs characterized by melanoma-specific biomarkers and upregulated gene transcripts involved in cell survival and prodevelopment functions. Implantation of Lin- population in NSG mice (CTC-derived xenografts, i.e., CDX), and subsequent transcriptomic analysis of ex vivo bone marrow-resident tumor cells (BMRTC) versus CTC identified protein ubiquitination as a significant regulatory pathway of BMRTC signaling. Selective inhibition of USP7, a key deubiquinating enzyme, arrested BMRTCs in bone marrow locales and decreased systemic micrometastasis. This study provides first-time evidence that the asymptomatic progression of metastatic melanoma can be recapitulated in vivo using patient-isolated CTCs. Furthermore, these results suggest that USP7 inhibitors warrant further investigation as a strategy to prevent progression to overt clinical metastasis.Significance: These findings provide insights into mechanism of melanoma recurrence and propose a novel approach to inhibit systematic metastatic disease by targeting bone marrow-resident tumor cells through pharmacological inhibition of USP7.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/78/18/5349/F1.large.jpg Cancer Res; 78(18); 5349-62. ©2018 AACR.
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Affiliation(s)
- Monika Vishnoi
- Biomarker Research Program Center, Houston Methodist Research Institute, Houston, Texas
| | - Debasish Boral
- Biomarker Research Program Center, Houston Methodist Research Institute, Houston, Texas
| | - Haowen Liu
- Biomarker Research Program Center, Houston Methodist Research Institute, Houston, Texas
| | - Marc L Sprouse
- Biomarker Research Program Center, Houston Methodist Research Institute, Houston, Texas
| | - Wei Yin
- Biomarker Research Program Center, Houston Methodist Research Institute, Houston, Texas
| | | | - Michael T Tetzlaff
- Department of Melanoma Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Michael A Davies
- Department of Melanoma Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Isabella C Glitza Oliva
- Department of Melanoma Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Dario Marchetti
- Biomarker Research Program Center, Houston Methodist Research Institute, Houston, Texas.
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32
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Tamberg N, Tahk S, Koit S, Kristjuhan K, Kasvandik S, Kristjuhan A, Ilves I. Keap1-MCM3 interaction is a potential coordinator of molecular machineries of antioxidant response and genomic DNA replication in metazoa. Sci Rep 2018; 8:12136. [PMID: 30108253 PMCID: PMC6092318 DOI: 10.1038/s41598-018-30562-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 08/02/2018] [Indexed: 01/19/2023] Open
Abstract
Coordination of DNA replication and cellular redox homeostasis mechanisms is essential for the sustained genome stability due to the sensitivity of replicating DNA to oxidation. However, substantial gaps remain in our knowledge of underlying molecular pathways. In this study, we characterise the interaction of Keap1, a central antioxidant response regulator in Metazoa, with the replicative helicase subunit protein MCM3. Our analysis suggests that structural determinants of the interaction of Keap1 with its critical downstream target - Nrf2 master transactivator of oxidative stress response genes – may have evolved in evolution to mimic the conserved helix-2-insert motif of MCM3. We show that this has led to a competition between MCM3 and Nrf2 proteins for Keap1 binding, and likely recruited MCM3 for the competitive binding dependent modulation of Keap1 controlled Nrf2 activities. We hypothesise that such mechanism could help to adjust the Keap1-Nrf2 antioxidant response pathway according to the proliferative and replicative status of the cell, with possible reciprocal implications also for the regulation of cellular functions of MCM3. Altogether this suggests about important role of Keap1-MCM3 interaction in the cross-talk between replisome and redox homeostasis machineries in metazoan cells.
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Affiliation(s)
- Nele Tamberg
- Institute of Technology, University of Tartu, Tartu, 50411, Estonia
| | - Siret Tahk
- Institute of Technology, University of Tartu, Tartu, 50411, Estonia
| | - Sandra Koit
- Institute of Technology, University of Tartu, Tartu, 50411, Estonia
| | - Kersti Kristjuhan
- Institute of Molecular and Cell Biology, University of Tartu, Tartu, 51010, Estonia
| | - Sergo Kasvandik
- Institute of Technology, University of Tartu, Tartu, 50411, Estonia
| | - Arnold Kristjuhan
- Institute of Molecular and Cell Biology, University of Tartu, Tartu, 51010, Estonia
| | - Ivar Ilves
- Institute of Technology, University of Tartu, Tartu, 50411, Estonia.
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33
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Emerging insights into HAUSP (USP7) in physiology, cancer and other diseases. Signal Transduct Target Ther 2018; 3:17. [PMID: 29967688 PMCID: PMC6023882 DOI: 10.1038/s41392-018-0012-y] [Citation(s) in RCA: 103] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 02/13/2018] [Accepted: 02/23/2018] [Indexed: 12/13/2022] Open
Abstract
Herpesvirus-associated ubiquitin-specific protease (HAUSP) is a USP family deubiquitinase. HAUSP is a protein of immense biological importance as it is involved in several cellular processes, including host-virus interactions, oncogenesis and tumor suppression, DNA damage and repair processes, DNA dynamics and epigenetic modulations, regulation of gene expression and protein function, spatio-temporal distribution, and immune functions. Since its discovery in the late 1990s as a protein interacting with a herpes virus regulatory protein, extensive studies have assessed its complex roles in p53-MDM2-related networks, identified numerous additional interacting partners, and elucidated the different roles of HAUSP in the context of cancer, development, and metabolic and neurological pathologies. Recent analyses have provided new insights into its biochemical and functional dynamics. In this review, we provide a comprehensive account of our current knowledge about emerging insights into HAUSP in physiology and diseases, which shed light on fundamental biological questions and promise to provide a potential target for therapeutic intervention. Improved understandings of a molecular-tag-removing enzyme could lead to the development of therapies for many diseases. Dr. Mrinal K Ghosh of the Council of Scientific and Industrial Research-Indian Institute of Chemical Biology (CSIR-IICB) and colleagues reviewed 20 years of research on herpesvirus-associated ubiquitin-specific protease (HAUSP), involved in a wide range of cellular processes through its role in removing the ubiquitin from molecules, thus signaling their fate. It was first discovered in/as a herpes virus infected cells, ultimately enhancing infection. It was later found to have a wide range of functions depending on the molecules it interacts with under normal physiological and disease conditions. Targeting HAUSP with drugs shows promise for suppressing prostate, lung, colon, breast, blood, and other cancers. It could also impact treatment of neurological conditions such as Huntington’s disease, and metabolic disorders, such as diabetes.
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34
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Yarychkivska O, Tavana O, Gu W, Bestor TH. Independent functions of DNMT1 and USP7 at replication foci. Epigenetics Chromatin 2018; 11:9. [PMID: 29482658 PMCID: PMC5828336 DOI: 10.1186/s13072-018-0179-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 02/16/2018] [Indexed: 01/06/2023] Open
Abstract
Background It has been reported that USP7 (ubiquitin-specific protease 7) prevents ubiquitylation and degradation of DNA methyltransferase 1 (DNMT1) by direct binding of USP7 to the glycine-lysine (GK) repeats that join the N-terminal regulatory domain of DNMT1 to the C-terminal methyltransferase domain. The USP7-DNMT1 interaction was reported to be mediated by acetylation of lysine residues within the (GK) repeats. Results We found that DNMT1 is present at normal levels in mouse and human cells that contain undetectable levels of USP7. Substitution of the (GK) repeats by (GQ) repeats prevents lysine acetylation but does not affect the stability of DNMT1 or the ability of the mutant protein to restore genomic methylation levels when expressed in Dnmt1-null ES cells. Furthermore, both USP7 and PCNA are recruited to sites of DNA replication independently of the presence of DNMT1, and there is no evidence that DNMT1 is degraded in cycling cells after S phase. Conclusions Multiple lines of evidence indicate that homeostasis of DNMT1 in somatic cells is controlled primarily at the level of transcription and that interaction of USP7 with the (GK) repeats of DNMT1 is unlikely to play a major role in the stabilization of DNMT1 protein.
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Affiliation(s)
- Olya Yarychkivska
- Department of Genetics and Development, College of Physicians and Surgeons, Columbia University, 701 W. 168th St, New York, NY, 10032, USA
| | - Omid Tavana
- Department of Pathology and Cell Biology, Institute for Cancer Genetics, College of Physicians and Surgeons, Columbia University, New York, NY, 10032, USA
| | - Wei Gu
- Department of Pathology and Cell Biology, Institute for Cancer Genetics, College of Physicians and Surgeons, Columbia University, New York, NY, 10032, USA
| | - Timothy H Bestor
- Department of Genetics and Development, College of Physicians and Surgeons, Columbia University, 701 W. 168th St, New York, NY, 10032, USA.
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35
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USP7-Specific Inhibitors Target and Modify the Enzyme's Active Site via Distinct Chemical Mechanisms. Cell Chem Biol 2017; 24:1501-1512.e5. [DOI: 10.1016/j.chembiol.2017.09.004] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 06/24/2017] [Accepted: 09/12/2017] [Indexed: 01/01/2023]
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36
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Kim RQ, Sixma TK. Regulation of USP7: A High Incidence of E3 Complexes. J Mol Biol 2017; 429:3395-3408. [DOI: 10.1016/j.jmb.2017.05.028] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 05/26/2017] [Accepted: 05/30/2017] [Indexed: 01/03/2023]
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37
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Hernández-Pérez S, Cabrera E, Salido E, Lim M, Reid L, Lakhani SR, Khanna KK, Saunus JM, Freire R. DUB3 and USP7 de-ubiquitinating enzymes control replication inhibitor Geminin: molecular characterization and associations with breast cancer. Oncogene 2017; 36:4802-4809. [PMID: 28288134 DOI: 10.1038/onc.2017.21] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 12/15/2016] [Accepted: 01/02/2017] [Indexed: 12/11/2022]
Abstract
Correct control of DNA replication is crucial to maintain genomic stability in dividing cells. Inappropriate re-licensing of replicated origins is associated with chromosomal instability (CIN), a hallmark of cancer progression that at the same time provides potential opportunities for therapeutic intervention. Geminin is a critical inhibitor of the DNA replication licensing factor Cdt1. To properly achieve its functions, Geminin levels are tightly regulated through the cell cycle by ubiquitin-dependent proteasomal degradation, but the de-ubiquitinating enzymes (DUBs) involved had not been identified. Here we report that DUB3 and USP7 control human Geminin. Overexpression of either DUB3 or USP7 increases Geminin levels through reduced ubiquitination. Conversely, depletion of DUB3 or USP7 reduces Geminin levels, and DUB3 knockdown increases re-replication events, analogous to the effect of Geminin depletion. In exploring potential clinical implications, we found that USP7 and Geminin are strongly correlated in a cohort of invasive breast cancers (P<1.01E-08). As expected, Geminin expression is highly prognostic. Interestingly, we found a non-monotonic relationship between USP7 and breast cancer-specific survival, with both very low or high levels of USP7 associated with poor outcome, independent of estrogen receptor status. Altogether, our data identify DUB3 and USP7 as factors that regulate DNA replication by controlling Geminin protein stability, and suggest that USP7 may be involved in Geminin dysregulation during breast cancer progression.
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Affiliation(s)
- S Hernández-Pérez
- Unidad de Investigación, Hospital Universitario de Canarias, Instituto de Tecnologías Biomédicas, La Laguna, Spain
| | - E Cabrera
- Unidad de Investigación, Hospital Universitario de Canarias, Instituto de Tecnologías Biomédicas, La Laguna, Spain
| | - E Salido
- Unidad de Investigación, Hospital Universitario de Canarias, Instituto de Tecnologías Biomédicas, La Laguna, Spain
| | - M Lim
- The University of Queensland, UQ Centre for Clinical Research, Herston, QLD, Australia.,QIMR Berghofer Medical Research Institute, Herston, QLD, Australia
| | - L Reid
- The University of Queensland, UQ Centre for Clinical Research, Herston, QLD, Australia.,QIMR Berghofer Medical Research Institute, Herston, QLD, Australia
| | - S R Lakhani
- The University of Queensland, UQ Centre for Clinical Research, Herston, QLD, Australia.,Pathology Queensland, The Royal Brisbane and Women's Hospital, Herston, QLD, Australia.,The University of Queensland, School of Medicine, Herston, QLD, Australia
| | - K K Khanna
- Signal Transduction Laboratory, QIMR Berghofer Institute of Medical Research, Brisbane, QLD, Australia
| | - J M Saunus
- The University of Queensland, UQ Centre for Clinical Research, Herston, QLD, Australia.,QIMR Berghofer Medical Research Institute, Herston, QLD, Australia
| | - R Freire
- Unidad de Investigación, Hospital Universitario de Canarias, Instituto de Tecnologías Biomédicas, La Laguna, Spain
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38
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Gambus A. Termination of Eukaryotic Replication Forks. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1042:163-187. [DOI: 10.1007/978-981-10-6955-0_8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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39
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Jin WL, Mao XY, Qiu GZ. Targeting Deubiquitinating Enzymes in Glioblastoma Multiforme: Expectations and Challenges. Med Res Rev 2016; 37:627-661. [PMID: 27775833 DOI: 10.1002/med.21421] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 09/06/2016] [Accepted: 09/25/2016] [Indexed: 12/16/2022]
Abstract
Glioblastoma (GBM) is regarded as the most common primary intracranial neoplasm. Despite standard treatment with tumor resection and radiochemotherapy, the outcome remains gloomy. It is evident that a combination of oncogenic gain of function and tumor-suppressive loss of function has been attributed to glioma initiation and progression. The ubiquitin-proteasome system is a well-orchestrated system that controls the fate of most proteins by striking a dynamic balance between ubiquitination and deubiquitination of substrates, having a profound influence on the modulation of oncoproteins, tumor suppressors, and cellular signaling pathways. In recent years, deubiquitinating enzymes (DUBs) have emerged as potential anti-cancer targets due to their targeting several key proteins involved in the regulation of tumorigenesis, apoptosis, senescence, and autophagy. This review attempts to summarize recent studies of GBM-associated DUBs, their roles in various cellular processes, and discuss the relation between DUBs deregulation and gliomagenesis, especially how DUBs regulate glioma stem cells pluripotency, microenvironment, and resistance of radiation and chemotherapy through core stem-cell transcriptional factors. We also review recent achievements and progress in the development of potent and selective reversible inhibitors of DUBs, and attempted to find a potential GBM treatment by DUBs intervention.
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Affiliation(s)
- 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 Jiao Tong University, Shanghai, 200240, P. R. China.,National Centers for Translational Medicine, Shanghai Jiao Tong University, Shanghai, 200240, P. R. China
| | - Xiao-Yuan Mao
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, 410008, P. R. China.,Institute of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Central South University, Changsha, 410078, P. R. China
| | - Guan-Zhong Qiu
- Department of Neurosurgery, General Hospital of Jinan Military Command, Jinan, 250031, P. R. China
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40
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Lecona E, Fernandez-Capetillo O. A SUMO and ubiquitin code coordinates protein traffic at replication factories. Bioessays 2016; 38:1209-1217. [DOI: 10.1002/bies.201600129] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Emilio Lecona
- Spanish National Cancer Research Centre; CNIO; Madrid Spain
| | - Oscar Fernandez-Capetillo
- Spanish National Cancer Research Centre; CNIO; Madrid Spain
- Science for Life Laboratory; Division of Translational Medicine and Chemical Biology; Department of Medical Biochemistry and Biophysics; Karolinska Institute; Stockholm Sweden
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41
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Abstract
DNA replication is both highly conserved and controlled. Problematic DNA replication can lead to genomic instability and therefore carcinogenesis. Numerous mechanisms work together to achieve this tight control and increasing evidence suggests that post-translational modifications (phosphorylation, ubiquitination, SUMOylation) of DNA replication proteins play a pivotal role in this process. Here we discuss such modifications in the light of a recent article that describes a novel role for the deubiquitinase (DUB) USP7/HAUSP in the control of DNA replication. USP7 achieves this function by an unusual and novel mechanism, namely deubiquitination of SUMOylated proteins at the replication fork, making USP7 also a SUMO DUB (SDUB). This work extends previous observations of increased levels of SUMO and low levels of ubiquitin at the on-going replication fork. Here, we discuss this novel study, its contribution to the DNA replication and genomic stability field and what questions arise from this work.
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Affiliation(s)
- Veronique A J Smits
- Unidad de Investigación, Hosptial Universitario de Canarias, Instituto de Tecnologías Biomédicas, La Laguna, Tenerife, Spain
| | - Raimundo Freire
- Unidad de Investigación, Hosptial Universitario de Canarias, Instituto de Tecnologías Biomédicas, La Laguna, Tenerife, Spain
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42
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USP37 deubiquitinates Cdt1 and contributes to regulate DNA replication. Mol Oncol 2016; 10:1196-206. [PMID: 27296872 DOI: 10.1016/j.molonc.2016.05.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Revised: 05/23/2016] [Accepted: 05/26/2016] [Indexed: 01/25/2023] Open
Abstract
DNA replication control is a key process in maintaining genomic integrity. Monitoring DNA replication initiation is particularly important as it needs to be coordinated with other cellular events and should occur only once per cell cycle. Crucial players in the initiation of DNA replication are the ORC protein complex, marking the origin of replication, and the Cdt1 and Cdc6 proteins, that license these origins to replicate by recruiting the MCM2-7 helicase. To accurately achieve its functions, Cdt1 is tightly regulated. Cdt1 levels are high from metaphase and during G1 and low in S/G2 phases of the cell cycle. This control is achieved, among other processes, by ubiquitination and proteasomal degradation. In an overexpression screen for Cdt1 deubiquitinating enzymes, we isolated USP37, to date the first ubiquitin hydrolase controlling Cdt1. USP37 overexpression stabilizes Cdt1, most likely a phosphorylated form of the protein. In contrast, USP37 knock down destabilizes Cdt1, predominantly during G1 and G1/S phases of the cell cycle. USP37 interacts with Cdt1 and is able to de-ubiquitinate Cdt1 in vivo and, USP37 is able to regulate the loading of MCM complexes onto the chromatin. In addition, downregulation of USP37 reduces DNA replication fork speed. Taken together, here we show that the deubiquitinase USP37 plays an important role in the regulation of DNA replication. Whether this is achieved via Cdt1, a central protein in this process, which we have shown to be stabilized by USP37, or via additional factors, remains to be tested.
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43
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Franz A, Ackermann L, Hoppe T. Ring of Change: CDC48/p97 Drives Protein Dynamics at Chromatin. Front Genet 2016; 7:73. [PMID: 27200082 PMCID: PMC4853748 DOI: 10.3389/fgene.2016.00073] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 04/16/2016] [Indexed: 12/31/2022] Open
Abstract
The dynamic composition of proteins associated with nuclear DNA is a fundamental property of chromosome biology. In the chromatin compartment dedicated protein complexes govern the accurate synthesis and repair of the genomic information and define the state of DNA compaction in vital cellular processes such as chromosome segregation or transcription. Unscheduled or faulty association of protein complexes with DNA has detrimental consequences on genome integrity. Consequently, the association of protein complexes with DNA is remarkably dynamic and can respond rapidly to cellular signaling events, which requires tight spatiotemporal control. In this context, the ring-like AAA+ ATPase CDC48/p97 emerges as a key regulator of protein complexes that are marked with ubiquitin or SUMO. Mechanistically, CDC48/p97 functions as a segregase facilitating the extraction of substrate proteins from the chromatin. As such, CDC48/p97 drives molecular reactions either by directed disassembly or rearrangement of chromatin-bound protein complexes. The importance of this mechanism is reflected by human pathologies linked to p97 mutations, including neurodegenerative disorders, oncogenesis, and premature aging. This review focuses on the recent insights into molecular mechanisms that determine CDC48/p97 function in the chromatin environment, which is particularly relevant for cancer and aging research.
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Affiliation(s)
- André Franz
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, Institute for Genetics, University of Cologne Cologne, Germany
| | - Leena Ackermann
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, Institute for Genetics, University of Cologne Cologne, Germany
| | - Thorsten Hoppe
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, Institute for Genetics, University of Cologne Cologne, Germany
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44
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USP7 is a SUMO deubiquitinase essential for DNA replication. Nat Struct Mol Biol 2016; 23:270-7. [PMID: 26950370 DOI: 10.1038/nsmb.3185] [Citation(s) in RCA: 108] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 02/04/2016] [Indexed: 12/15/2022]
Abstract
Post-translational modification of proteins by ubiquitin (Ub) and Ub-like modifiers regulates DNA replication. We have previously shown that chromatin around replisomes is rich in SUMO and poor in Ub, whereas mature chromatin exhibits an opposite pattern. How this SUMO-rich, Ub-poor environment is maintained at sites of DNA replication in mammalian cells remains unexplored. Here we identify USP7 as a replisome-enriched SUMO deubiquitinase that is essential for DNA replication. By acting on SUMO and SUMOylated proteins, USP7 counteracts their ubiquitination. Inhibition or genetic deletion of USP7 leads to the accumulation of Ub on SUMOylated proteins, which are displaced away from replisomes. Our findings provide a model explaining the differential accumulation of SUMO and Ub at replication forks and identify an essential role of USP7 in DNA replication that should be considered in the development of USP7 inhibitors as anticancer agents.
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45
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Ding X, Jiang W, Zhou P, Liu L, Wan X, Yuan X, Wang X, Chen M, Chen J, Yang J, Kong C, Li B, Peng C, Wong CCL, Hou F, Zhang Y. Mixed Lineage Leukemia 5 (MLL5) Protein Stability Is Cooperatively Regulated by O-GlcNac Transferase (OGT) and Ubiquitin Specific Protease 7 (USP7). PLoS One 2015; 10:e0145023. [PMID: 26678539 PMCID: PMC4683056 DOI: 10.1371/journal.pone.0145023] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 11/28/2015] [Indexed: 02/07/2023] Open
Abstract
Mixed lineage leukemia 5 (MLL5) protein is a trithorax family histone 3 lysine 4 (H3K4) methyltransferase that regulates diverse biological processes, including cell cycle progression, hematopoiesis and cancer. The mechanisms by which MLL5 protein stability is regulated have remained unclear to date. Here, we showed that MLL5 protein stability is cooperatively regulated by O-GlcNAc transferase (OGT) and ubiquitin-specific protease 7 (USP7). Depletion of OGT in cells led to a decrease in the MLL5 protein level through ubiquitin/proteasome-dependent proteolytic degradation, whereas ectopic expression of OGT protein suppressed MLL5 ubiquitylation. We further identified deubiquitinase USP7 as a novel MLL5-associated protein using mass spectrometry. USP7 stabilized the MLL5 protein through direct binding and deubiquitylation. Loss of USP7 induced degradation of MLL5 protein. Conversely, overexpression of USP7, but not a catalytically inactive USP7 mutant, led to decreased ubiquitylation and increased MLL5 stability. Co-immunoprecipitation and co-immunostaining assays revealed that MLL5, OGT and USP7 interact with each other to form a stable ternary complex that is predominantly located in the nucleus. In addition, upregulation of MLL5 expression was correlated with increased expression of OGT and USP7 in human primary cervical adenocarcinomas. Our results collectively reveal a novel molecular mechanism underlying regulation of MLL5 protein stability and provide new insights into the functional interplay among O-GlcNAc transferase, deubiquitinase and histone methyltransferase.
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Affiliation(s)
- Xiaodan Ding
- Department of Immunology, Nanjing Medical University, Jiangsu, China
- Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
| | - Wei Jiang
- Shanghai Red House Obstetrics and Gynecology Hospital, Fudan University, Shanghai, China
- * E-mail: (WJ); (YZ)
| | - Peipei Zhou
- Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
| | - Lulu Liu
- Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
- Institute of Biology and Medical Sciences, Soochow University, Jiangsu, China
| | - Xiaoling Wan
- Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
| | - Xiujie Yuan
- Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
| | - Xizi Wang
- College of life science, Sun Yet-Sen University, Guangzhou, China
| | - Miao Chen
- Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
- College of Life Science, Shanghai Normal University, Shanghai, China
| | - Jun Chen
- College of Life Science, Shanghai Normal University, Shanghai, China
| | - Jing Yang
- Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
| | - Chao Kong
- Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
| | - Bin Li
- Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
| | - Chao Peng
- National Center for Protein Science Shanghai, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Catherine C. L. Wong
- National Center for Protein Science Shanghai, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Fajian Hou
- National Center for Protein Science Shanghai, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Yan Zhang
- Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
- * E-mail: (WJ); (YZ)
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46
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Pozhidaeva AK, Mohni KN, Dhe-Paganon S, Arrowsmith CH, Weller SK, Korzhnev DM, Bezsonova I. Structural Characterization of Interaction between Human Ubiquitin-specific Protease 7 and Immediate-Early Protein ICP0 of Herpes Simplex Virus-1. J Biol Chem 2015. [PMID: 26224631 DOI: 10.1074/jbc.m115.664805] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Human ubiquitin-specific protease 7 (USP7) is a deubiquitinating enzyme that prevents protein degradation by removing polyubiquitin chains from its substrates. It regulates the stability of a number of human transcription factors and tumor suppressors and plays a critical role in the development of several types of cancer, including prostate and small cell lung cancer. In addition, human USP7 is targeted by several viruses of the Herpesviridae family and is required for effective herpesvirus infection. The USP7 C-terminal region (C-USP7) contains five ubiquitin-like domains (UBL1-5) that interact with several USP7 substrates. Although structures of the USP7 C terminus bound to its substrates could provide vital information for understanding USP7 substrate specificity, no such data has been available to date. In this work we have demonstrated that the USP7 ubiquitin-like domains can be studied in isolation by solution NMR spectroscopy, and we have determined the structure of the UBL1 domain. Furthermore, we have employed NMR and viral plaque assays to probe the interaction between the C-USP7 and HSV-1 immediate-early protein ICP0 (infected cell protein 0), which is essential for efficient lytic infection and virus reactivation from latency. We have shown that depletion of the USP7 in HFF-1 cells negatively affects the efficiency of HSV-1 lytic infection. We have also found that USP7 directly binds ICP0 via its C-terminal UBL1-2 domains and mapped the USP7-binding site for ICP0. Therefore, this study represents a first step toward understanding the molecular mechanism of C-USP7 specificity toward its substrates and may provide the basis for future development of novel antiviral and anticancer therapies.
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Affiliation(s)
- Alexandra K Pozhidaeva
- From the Department of Molecular Biology and Biophysics, University of Connecticut Health, Farmington, Connecticut 06030
| | - Kareem N Mohni
- the Department of Biochemistry, Vanderbilt University Medical Center, Nashville, Tennessee 37232
| | - Sirano Dhe-Paganon
- the Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts 02215, and
| | - Cheryl H Arrowsmith
- the Structural Genomics Consortium, University of Toronto, Toronto, Ontario M5G 1L7, Canada
| | - Sandra K Weller
- From the Department of Molecular Biology and Biophysics, University of Connecticut Health, Farmington, Connecticut 06030
| | - Dmitry M Korzhnev
- From the Department of Molecular Biology and Biophysics, University of Connecticut Health, Farmington, Connecticut 06030
| | - Irina Bezsonova
- From the Department of Molecular Biology and Biophysics, University of Connecticut Health, Farmington, Connecticut 06030,
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47
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Crystal Structure of USP7 Ubiquitin-like Domains with an ICP0 Peptide Reveals a Novel Mechanism Used by Viral and Cellular Proteins to Target USP7. PLoS Pathog 2015; 11:e1004950. [PMID: 26046769 PMCID: PMC4457826 DOI: 10.1371/journal.ppat.1004950] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 05/11/2015] [Indexed: 01/01/2023] Open
Abstract
Herpes simplex virus-1 immediate-early protein ICP0 activates viral genes during early stages of infection, affects cellular levels of multiple host proteins and is crucial for effective lytic infection. Being a RING-type E3 ligase prone to auto-ubiquitination, ICP0 relies on human deubiquitinating enzyme USP7 for protection against 26S proteasomal mediated degradation. USP7 is involved in apoptosis, epigenetics, cell proliferation and is targeted by several herpesviruses. Several USP7 partners, including ICP0, GMPS, and UHRF1, interact through its C-terminal domain (CTD), which contains five ubiquitin-like (Ubl) structures. Despite the fact that USP7 has emerged as a drug target for cancer therapy, structural details of USP7 regulation and the molecular mechanism of interaction at its CTD have remained elusive. Here, we mapped the binding site between an ICP0 peptide and USP7 and determined the crystal structure of the first three Ubl domains bound to the ICP0 peptide, which showed that ICP0 binds to a loop on Ubl2. Sequences similar to the USP7-binding site in ICP0 were identified in GMPS and UHRF1 and shown to bind USP7-CTD through Ubl2. In addition, co-immunoprecipitation assays in human cells comparing binding to USP7 with and without a Ubl2 mutation, confirmed the importance of the Ubl2 binding pocket for binding ICP0, GMPS and UHRF1. Therefore we have identified a novel mechanism of USP7 recognition that is used by both viral and cellular proteins. Our structural information was used to generate a model of near full-length USP7, showing the relative position of the ICP0/GMPS/UHRF1 binding pocket and the structural basis by which it could regulate enzymatic activity. USP7 is a cellular protein that binds and stabilizes many proteins involved in multiple pathways that regulate oncogenesis and as such is recognized as a potential target for cancer therapy. In addition, USP7 is targeted by several viral proteins in order to promote cell survival and viral infection. One such protein is the ICP0 protein of herpes simplex virus 1, which must bind USP7 in order to manipulate the cell in ways that enable efficient viral infection. Here we use a structural approach to define the mechanism of the USP7-ICP0 peptide interaction, revealing a novel binding site on USP7. We then used this information to identify two cellular proteins, GMPS and UHRF1, that also bind USP7 through this binding site. Therefore we have identified a new mechanism by which both viral and cellular proteins can target USP7. This information will be useful for the development of strategies to block specific protein interactions with USP7.
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48
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Abstract
To ensure duplication of the entire genome, eukaryotic DNA replication initiates from thousands of replication origins. The replication forks move through the chromatin until they encounter forks from neighboring origins. During replication fork termination forks converge, the replisomes disassemble and topoisomerase II resolves the daughter DNA molecules. If not resolved efficiently, terminating forks result in genomic instability through the formation of pathogenic structures. Our recent findings shed light onto the mechanism of replisome disassembly upon replication fork termination. We have shown that termination-specific polyubiquitylation of the replicative helicase component – Mcm7, leads to dissolution of the active helicase in a process dependent on the p97/VCP/Cdc48 segregase. The inhibition of terminating helicase disassembly resulted in a replication termination defect. In this extended view we present hypothetical models of replication fork termination and discuss remaining and emerging questions in the DNA replication termination field.
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Key Words
- CMG, Cdc45, Mcm2–7, GINS complex
- CRL, cullin-RING ligase
- D loop, displacement loop
- DDR, DNA damage response
- DNA replication
- DSB, double strand break
- DUB, deubiquitylating enzyme
- ER, endoplasmic reticulum
- ERAD, endoplasmic reticulum associated protein degradation
- GINS, Go-Ichi-Ni-San, complex made of Sld5, Psf1, Psf2, Psf3
- ICL, intra-strand crosslink
- MCM, Minichromosome maintenance
- Mcm2–7
- OriC, chromosomal replication origin
- R loop, RNA:DNA hybrid
- RING, really interesting gene
- RPC, Replisome Progression Complex
- Ter, termination site
- Tus-Ter, terminus utilisation substance - termination
- Xenopus
- p97 segregase
- replication termination
- replicative helicase
- replisome
- ubiquitin
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Affiliation(s)
- Rachael Bailey
- a School of Cancer Sciences; University of Birmingham ; Birmingham , UK
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49
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Qian J, Pentz K, Zhu Q, Wang Q, He J, Srivastava AK, Wani AA. USP7 modulates UV-induced PCNA monoubiquitination by regulating DNA polymerase eta stability. Oncogene 2014; 34:4791-6. [PMID: 25435364 PMCID: PMC4451444 DOI: 10.1038/onc.2014.394] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 10/02/2014] [Accepted: 10/27/2014] [Indexed: 12/27/2022]
Abstract
DNA polymerase eta (Polη) plays unique and pivotal functions in several DNA damage-tolerance pathways. Steady-state level of this short-lived protein is tightly controlled by multiple mechanisms including proteolysis. Here, we have identified the deubiquitinating enzyme, ubiquitin-specific protease 7 (USP7), as a novel regulator of Polη stability. USP7 regulates Polη stability through both indirect and direct mechanisms. Knockout of USP7 increased the steady-state level of Polη and slowed down the turnover of both Polη and p53 proteins through destabilizing their E3 ligase Mdm2. Also, USP7 physically binds Polη in vitro and in vivo. Overexpression of wild-type USP7 but not its catalytically-defective mutants deubiquitinates Polη and increases its cellular steady-state level. Thus, USP7 directly serves as a specific deubiquitinating enzyme for Polη. Furthermore, ectopic expression of USP7 promoted the UV-induced PCNA monoubiquitination in Polη-proficient but not Polη-deficient XPV cells, suggesting that USP7 facilitates UV-induced PCNA monoubiquitination by stabilizing Polη. Taken together, our findings reveal a modulatory role of USP7 in PCNA ubiquitination-mediated stress-tolerance pathways by fine-tuning Polη turnover.
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Affiliation(s)
- J Qian
- Department of Radiology, The Ohio State University, Columbus, OH, USA
| | - K Pentz
- Department of Radiology, The Ohio State University, Columbus, OH, USA
| | - Q Zhu
- Department of Radiology, The Ohio State University, Columbus, OH, USA
| | - Q Wang
- Department of Radiology, The Ohio State University, Columbus, OH, USA
| | - J He
- Department of Radiology, The Ohio State University, Columbus, OH, USA
| | - A K Srivastava
- Department of Radiology, The Ohio State University, Columbus, OH, USA
| | - A A Wani
- Department of Radiology, The Ohio State University, Columbus, OH, USA.,Department of Molecular and Cellular Biochemistry, The Ohio State University, Columbus, OH, USA.,James Cancer Hospital and Solove Research Institute, The Ohio State University, Columbus, OH, USA
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50
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Moreno SP, Bailey R, Campion N, Herron S, Gambus A. Polyubiquitylation drives replisome disassembly at the termination of DNA replication. Science 2014; 346:477-81. [PMID: 25342805 DOI: 10.1126/science.1253585] [Citation(s) in RCA: 141] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Resolution of replication forks during termination of DNA replication is essential for accurate duplication of eukaryotic genomes. Here we present evidence consistent with the idea that polyubiquitylation of a replisome component (Mcm7) leads to its disassembly at the converging terminating forks because of the action of the p97/VCP/Cdc48 protein remodeler. Using Xenopus laevis egg extract, we have shown that blocking polyubiquitylation results in the prolonged association of the active helicase with replicating chromatin. The Mcm7 subunit is the only component of the active helicase that we find polyubiquitylated during replication termination. The observed polyubiquitylation is followed by disassembly of the active helicase dependent on p97/VCP/Cdc48. Altogether, our data provide insight into the mechanism of replisome disassembly during eukaryotic DNA replication termination.
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Affiliation(s)
- Sara Priego Moreno
- School of Cancer Sciences, University of Birmingham, Vincent Drive, Birmingham B15 2TT, UK
| | - Rachael Bailey
- School of Cancer Sciences, University of Birmingham, Vincent Drive, Birmingham B15 2TT, UK
| | - Nicholas Campion
- School of Cancer Sciences, University of Birmingham, Vincent Drive, Birmingham B15 2TT, UK
| | - Suzanne Herron
- School of Cancer Sciences, University of Birmingham, Vincent Drive, Birmingham B15 2TT, UK
| | - Agnieszka Gambus
- School of Cancer Sciences, University of Birmingham, Vincent Drive, Birmingham B15 2TT, UK.
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