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Liu S, Tackmann NR, Yang J, Zhang Y. Disruption of the RP-MDM2-p53 pathway accelerates APC loss-induced colorectal tumorigenesis. Oncogene 2016; 36:1374-1383. [PMID: 27617574 PMCID: PMC5693310 DOI: 10.1038/onc.2016.301] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 06/21/2016] [Accepted: 07/17/2016] [Indexed: 12/11/2022]
Abstract
Inactivation of the adenomatous polyposis coli (APC) tumor suppressor is frequently found in colorectal cancer. Loss of APC function results in deregulation of the Wnt/β-catenin signaling pathway causing overexpression of the c-MYC oncogene. In lymphoma, both p19ARF and ribosomal proteins RPL11 and RPL5 respond to c-MYC activation to induce p53. Their role in c-MYC-driven colorectal carcinogenesis is unclear, as p19ARF deletion does not accelerate APC loss-triggered intestinal tumorigenesis. To determine the contribution of the RP-MDM2-p53 pathway to APC loss-induced tumorigenesis, we crossed mice bearing MDM2C305F mutation, which disrupts RPL11- and RPL5-MDM2 binding, with Apcmin/+ mice, which are prone to intestinal tumor formation. Interestingly, loss of RP-MDM2 binding significantly accelerated colorectal tumor formation while having no discernable effect on small intestinal tumor formation. Mechanistically, APC loss leads to overexpression of c-MYC, RPL11 and RPL5 in mouse colonic tumor cells irrespective of MDM2C305F mutation. However, notable p53 stabilization and activation were observed only in Apcmin/+;Mdm2+/+ but not Apcmin/+;Mdm2C305F/C305F colon tumors. These data establish that the RP-MDM2-p53 pathway, in contrast to the p19ARF-MDM2-p53 pathway, is a critical mediator of colorectal tumorigenesis following APC loss.
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Affiliation(s)
- S Liu
- Department of Radiation Oncology and Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - N R Tackmann
- Department of Radiation Oncology and Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.,Curriculum in Genetics and Molecular Biology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - J Yang
- Department of Radiation Oncology and Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.,Jiangsu Center for the Collaboration and Innovation of Cancer Biotherapy, Cancer Institute, Xuzhou Medical College, Xuzhou, Jiangsu, China
| | - Y Zhang
- Department of Radiation Oncology and Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.,Curriculum in Genetics and Molecular Biology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.,Jiangsu Center for the Collaboration and Innovation of Cancer Biotherapy, Cancer Institute, Xuzhou Medical College, Xuzhou, Jiangsu, China
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52
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Meng X, Tackmann NR, Liu S, Yang J, Dong J, Wu C, Cox AD, Zhang Y. RPL23 Links Oncogenic RAS Signaling to p53-Mediated Tumor Suppression. Cancer Res 2016; 76:5030-9. [PMID: 27402081 DOI: 10.1158/0008-5472.can-15-3420] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 06/27/2016] [Indexed: 11/16/2022]
Abstract
The ribosomal protein (RP)-MDM2 interaction is a p53 response pathway critical for preventing oncogenic c-MYC-induced tumorigenesis. To investigate whether the RP-MDM2-p53 pathway is a broad antioncogenic mechanism, we crossed mice bearing an MDM2(C305F) mutation, which disrupts RPL11 binding to MDM2, with mice expressing an oncogenic Hras(G12V) transgene. Interestingly, the MDM2(C305F)-mutant mice, which are hypersensitive to c-MYC-induced tumorigenesis, are not hypersensitive to oncogenic Hras(G12V)-induced tumorigenesis. Unlike c-MYC, which induces expression of RPL11, RAS overexpression leads to an increase in RPL23 mRNA and protein whereas RPL11 expression remains unchanged. The induction of RPL23 involves both MEK and PI3K signaling pathways and requires mTOR function. Increased expression of RPL23, which maintains binding to MDM2(C305F) mutant, correlates with increased p53 expression in MDM2(C305F) cells. Furthermore, RAS overexpression can induce p53 in the absence of p19ARF, and the induction can be abolished by downregulation of RPL23. Thus, although the RPL11-MDM2-p53 pathway coordinates with the p19ARF-MDM2-p53 pathway against oncogenic c-MYC-induced tumorigenesis, the RPL23-MDM2-p53 pathway coordinates with the p19ARF-MDM2-p53 pathway against oncogenic RAS-induced tumorigenesis. Cancer Res; 76(17); 5030-9. ©2016 AACR.
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Affiliation(s)
- Xuan Meng
- Department of Radiation Oncology, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina. Jiangsu Center for the Collaboration and Innovation of Cancer Biotherapy, Cancer Institute, Xuzhou Medical College, Xuzhou, Jiangsu, China. Hospital and Institute of Hepatobiliary Surgery, Chinese PLA General Hospital, Beijing, China. School of Basic Medical Sciences and Institute of System Biomedicine, Peking University, Beijing, China
| | - Nicole R Tackmann
- Department of Radiation Oncology, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina. Curriculum in Genetics and Molecular Biology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Shijie Liu
- Department of Radiation Oncology, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Jing Yang
- Department of Radiation Oncology, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina. Jiangsu Center for the Collaboration and Innovation of Cancer Biotherapy, Cancer Institute, Xuzhou Medical College, Xuzhou, Jiangsu, China
| | - Jiahong Dong
- Hospital and Institute of Hepatobiliary Surgery, Chinese PLA General Hospital, Beijing, China. School of Basic Medical Sciences and Institute of System Biomedicine, Peking University, Beijing, China. Beijing Tsinghua Changgung Hospital, Tsinghua Medical Center, Changping District, Beijing, China
| | - Congying Wu
- School of Basic Medical Sciences and Institute of System Biomedicine, Peking University, Beijing, China
| | - Adrienne D Cox
- Department of Radiation Oncology, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina. Curriculum in Genetics and Molecular Biology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Yanping Zhang
- Department of Radiation Oncology, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina. Jiangsu Center for the Collaboration and Innovation of Cancer Biotherapy, Cancer Institute, Xuzhou Medical College, Xuzhou, Jiangsu, China. Curriculum in Genetics and Molecular Biology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
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53
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Xu X, Xiong X, Sun Y. The role of ribosomal proteins in the regulation of cell proliferation, tumorigenesis, and genomic integrity. SCIENCE CHINA-LIFE SCIENCES 2016; 59:656-72. [DOI: 10.1007/s11427-016-0018-0] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 04/06/2016] [Indexed: 01/29/2023]
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54
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Jorquera R, Ortiz R, Ossandon F, Cárdenas JP, Sepúlveda R, González C, Holmes DS. SinEx DB: a database for single exon coding sequences in mammalian genomes. DATABASE-THE JOURNAL OF BIOLOGICAL DATABASES AND CURATION 2016; 2016:baw095. [PMID: 27278816 PMCID: PMC4897596 DOI: 10.1093/database/baw095] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2015] [Accepted: 05/11/2016] [Indexed: 12/27/2022]
Abstract
Eukaryotic genes are typically interrupted by intragenic, noncoding sequences termed introns. However, some genes lack introns in their coding sequence (CDS) and are generally known as 'single exon genes' (SEGs). In this work, a SEG is defined as a nuclear, protein-coding gene that lacks introns in its CDS. Whereas, many public databases of Eukaryotic multi-exon genes are available, there are only two specialized databases for SEGs. The present work addresses the need for a more extensive and diverse database by creating SinEx DB, a publicly available, searchable database of predicted SEGs from 10 completely sequenced mammalian genomes including human. SinEx DB houses the DNA and protein sequence information of these SEGs and includes their functional predictions (KOG) and the relative distribution of these functions within species. The information is stored in a relational database built with My SQL Server 5.1.33 and the complete dataset of SEG sequences and their functional predictions are available for downloading. SinEx DB can be interrogated by: (i) a browsable phylogenetic schema, (ii) carrying out BLAST searches to the in-house SinEx DB of SEGs and (iii) via an advanced search mode in which the database can be searched by key words and any combination of searches by species and predicted functions. SinEx DB provides a rich source of information for advancing our understanding of the evolution and function of SEGs.Database URL: www.sinex.cl.
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Affiliation(s)
- Roddy Jorquera
- Center for Bioinformatics and Genome Biology, Fundacion Ciencia & Vida and Facultad de Ciencias Biologicas, Universidad Andres Bello, Avda Zañartu 1482, Santiago, Chile
| | - Rodrigo Ortiz
- Center for Bioinformatics and Genome Biology, Fundacion Ciencia & Vida and Facultad de Ciencias Biologicas, Universidad Andres Bello, Avda Zañartu 1482, Santiago, Chile
| | - F Ossandon
- Center for Bioinformatics and Genome Biology, Fundacion Ciencia & Vida and Facultad de Ciencias Biologicas, Universidad Andres Bello, Avda Zañartu 1482, Santiago, Chile
| | - Juan Pablo Cárdenas
- Center for Bioinformatics and Genome Biology, Fundacion Ciencia & Vida and Facultad de Ciencias Biologicas, Universidad Andres Bello, Avda Zañartu 1482, Santiago, Chile
| | - Rene Sepúlveda
- Center for Bioinformatics and Genome Biology, Fundacion Ciencia & Vida and Facultad de Ciencias Biologicas, Universidad Andres Bello, Avda Zañartu 1482, Santiago, Chile
| | - Carolina González
- Center for Bioinformatics and Genome Biology, Fundacion Ciencia & Vida and Facultad de Ciencias Biologicas, Universidad Andres Bello, Avda Zañartu 1482, Santiago, Chile
| | - David S Holmes
- Center for Bioinformatics and Genome Biology, Fundacion Ciencia & Vida and Facultad de Ciencias Biologicas, Universidad Andres Bello, Avda Zañartu 1482, Santiago, Chile
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55
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Jung JH, Kim MJ, Lee H, Lee J, Kim J, Lee HJ, Shin EA, Kim YH, Kim B, Shim BS, Kim SH. Farnesiferol c induces apoptosis via regulation of L11 and c-Myc with combinational potential with anticancer drugs in non-small-cell lung cancers. Sci Rep 2016; 6:26844. [PMID: 27231235 PMCID: PMC4882547 DOI: 10.1038/srep26844] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 04/20/2016] [Indexed: 12/16/2022] Open
Abstract
Though Farnesiferol c (FC) has been reported to have anti-angiogenic and antitumor activity, the underlying antitumor mechanism of FC still remains unclear. Thus, in the present study, we investigated the apoptotic mechanism of FC in human H1299 and H596 non-small lung cancer cells (NSCLCs). FC significantly showed cytotoxicity, increased sub-G1 accumulation, and attenuated the expression of Bcl-2, Bcl-xL, Survivin and procaspase 3 in H1299 and H596 cells. Furthermore, FC effectively suppressed the mRNA expression of G1 arrest related genes such as Cyclin D1, E2F1 transcription factor and CDC25A by RT-PCR. Interestingly, FC inhibited the expression of c-Myc, ribosomal protein L11 (L11) and nucleolin (NCL) in H1299 and H596 cells. Of note, silencing of L11 by siRNA transfection enhanced the expression of c-Myc through a negative feedback mechanism, while c-Myc knockdown downregulated L11 in H1299 cells. Additionally, combined treatment of FC and puromycin/doxorubicin promoted the activation of caspase 9/3, and attenuated the expression of c-Myc, Cyclin D1 and CDK4 in H1299 cells compared to single treatment. Taken together, our findings suggest that FC induces apoptosis and G1 arrest via regulation of ribosomal protein L11 and c-Myc and also enhances antitumor effect of puromycin or doxorubicin in NSCLCs.
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Affiliation(s)
- Ji Hoon Jung
- College of Korean Medicine, Kyung Hee University, Seoul, South Korea
| | - Moon Joon Kim
- College of Korean Medicine, Kyung Hee University, Seoul, South Korea
| | - Hyemin Lee
- College of Korean Medicine, Kyung Hee University, Seoul, South Korea
| | - Jihyun Lee
- College of Korean Medicine, Kyung Hee University, Seoul, South Korea
| | - Jaekwang Kim
- College of Korean Medicine, Kyung Hee University, Seoul, South Korea
| | - Hyun Joo Lee
- College of Korean Medicine, Kyung Hee University, Seoul, South Korea
| | - Eun Ah Shin
- College of Korean Medicine, Kyung Hee University, Seoul, South Korea
| | - Yoon Hyeon Kim
- Graduate School of East-West Medical Science, Kyung Hee University, Yongin, South Korea
| | - Bonglee Kim
- College of Korean Medicine, Kyung Hee University, Seoul, South Korea
| | - Bum Sang Shim
- College of Korean Medicine, Kyung Hee University, Seoul, South Korea
| | - Sung-Hoon Kim
- College of Korean Medicine, Kyung Hee University, Seoul, South Korea
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56
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Liu Y, Deisenroth C, Zhang Y. RP-MDM2-p53 Pathway: Linking Ribosomal Biogenesis and Tumor Surveillance. Trends Cancer 2016; 2:191-204. [PMID: 28741571 DOI: 10.1016/j.trecan.2016.03.002] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Revised: 03/03/2016] [Accepted: 03/04/2016] [Indexed: 12/18/2022]
Abstract
Ribosomal biogenesis is tightly associated with cellular activities, such as growth, proliferation, and cell cycle progression. Perturbations in ribosomal biogenesis can initiate so-called nucleolar stress. The process through which ribosomal proteins (RPs) transduce nucleolar stress signals via MDM2 to p53 has been described as a crucial tumor-suppression mechanism. In this review we focus on recent progress pertaining to the function and mechanism of RPs in association with the MDM2-p53 tumor-suppression network, and the potential implications this surveillance network has for cancer development.
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Affiliation(s)
- Yong Liu
- Department of Radiation Oncology and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Chad Deisenroth
- The Hamner Institutes for Health Sciences, Institute for Chemical Safety Sciences, 6 Davis Drive, PO Box 12137, Research Triangle Park, NC 27709, USA
| | - Yanping Zhang
- Department of Radiation Oncology and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Jiangsu Center for the Collaboration and Innovation of Cancer Biotherapy, Cancer Institute, Xuzhou Medical College, Xuzhou, Jiangsu 221002, China.
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57
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He X, Li Y, Dai MS, Sun XX. Ribosomal protein L4 is a novel regulator of the MDM2-p53 loop. Oncotarget 2016; 7:16217-26. [PMID: 26908445 PMCID: PMC4941309 DOI: 10.18632/oncotarget.7479] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 02/09/2016] [Indexed: 12/29/2022] Open
Abstract
A number of ribosomal proteins (RPs) have been shown to play a critical role in coordinating ribosome biogenesis with cell growth and proliferation by suppressing MDM2 to induce p53 activation. While how the MDM2-p53 pathway is regulated by multiple RPs is unclear, it remains to be interesting to identify additional RPs that can regulate this pathway. Here we report that ribosomal protein L4 (RPL4) directly interacts with MDM2 at the central acidic domain and suppresses MDM2-mediated p53 ubiquitination and degradation, leading to p53 stabilization and activation. Interestingly, overexpression of RPL4 promotes the binding of MDM2 to RPL5 and RPL11 and forms a complex with RPL5, RPL11 and MDM2 in cells. Conversely, knockdown of RPL4 also induces p53 levels and p53-dependent cell cycle arrest. This p53-dependent effect requires both RPL5 and RPL11, suggesting that depletion of RPL4 triggers ribosomal stress. Together, our results reveal that balanced levels of RPL4 are critical for normal cell growth and proliferation via regulating the MDM2-p53 loop.
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Affiliation(s)
- Xia He
- Department of Molecular and Medical Genetics, School of Medicine and the OHSU Knight Cancer Institute, Oregon Health & Science University, Portland, OR, USA
- Department of Radiation Oncology, Jiangsu Cancer Hospital, Nanjing, China
| | - Yuhuang Li
- Department of Molecular and Medical Genetics, School of Medicine and the OHSU Knight Cancer Institute, Oregon Health & Science University, Portland, OR, USA
| | - Mu-Shui Dai
- Department of Molecular and Medical Genetics, School of Medicine and the OHSU Knight Cancer Institute, Oregon Health & Science University, Portland, OR, USA
| | - Xiao-Xin Sun
- Department of Molecular and Medical Genetics, School of Medicine and the OHSU Knight Cancer Institute, Oregon Health & Science University, Portland, OR, USA
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58
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Dinman JD. Pathways to Specialized Ribosomes: The Brussels Lecture. J Mol Biol 2016; 428:2186-94. [PMID: 26764228 DOI: 10.1016/j.jmb.2015.12.021] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 12/23/2015] [Accepted: 12/24/2015] [Indexed: 12/17/2022]
Abstract
"Specialized ribosomes" is a topic of intense debate and research whose provenance can be traced to the earliest days of molecular biology. Here, the history of this idea is reviewed, and critical literature in which the specialized ribosomes have come to be presently defined is discussed. An argument supporting the evolution of a variety of ribosomes with specialized functions as a consequence of selective pressures acting on a near-infinite set of possible ribosomes is presented, leading to a discussion of how this may also serve as a biological buffering mechanism. The possible relationship between specialized ribosomes and human health is explored. A set of criteria and possible approaches are also presented to help guide the definitive identification of "specialized" ribosomes, and this is followed by a discussion of how synthetic biology approaches might be used to create new types of special ribosomes.
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Affiliation(s)
- Jonathan D Dinman
- Department of Cell Biology and Molecular Genetics, University of Maryland, 4062 Campus Drive, College Park, MD 20742, USA.
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59
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Mazur AJ, Radaszkiewicz T, Makowiecka A, Malicka-Błaszkiewicz M, Mannherz HG, Nowak D. Gelsolin interacts with LamR, hnRNP U, nestin, Arp3 and β-tubulin in human melanoma cells as revealed by immunoprecipitation and mass spectrometry. Eur J Cell Biol 2016; 95:26-41. [DOI: 10.1016/j.ejcb.2015.11.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 10/08/2015] [Accepted: 11/04/2015] [Indexed: 01/25/2023] Open
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60
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Prokhorova EA, Zamaraev AV, Kopeina GS, Zhivotovsky B, Lavrik IN. Role of the nucleus in apoptosis: signaling and execution. Cell Mol Life Sci 2015; 72:4593-612. [PMID: 26346492 PMCID: PMC11113907 DOI: 10.1007/s00018-015-2031-y] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Revised: 08/06/2015] [Accepted: 08/27/2015] [Indexed: 02/06/2023]
Abstract
Since their establishment in the early 1970s, the nuclear changes upon apoptosis induction, such as the condensation of chromatin, disassembly of nuclear scaffold proteins and degradation of DNA, were, and still are, considered as the essential steps and hallmarks of apoptosis. These are the characteristics of the execution phase of apoptotic cell death. In addition, accumulating data clearly show that some nuclear events can lead to the induction of apoptosis. In particular, if DNA lesions resulting from deregulation during the cell cycle or DNA damage induced by chemotherapeutic drugs or viral infection cannot be efficiently eliminated, apoptotic mechanisms, which enable cellular transformation to be avoided, are activated in the nucleus. The functional heterogeneity of the nuclear organization allows the tight regulation of these signaling events that involve the movement of various nuclear proteins to other intracellular compartments (and vice versa) to initiate and govern apoptosis. Here, we discuss how these events are coordinated to execute apoptotic cell death.
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Affiliation(s)
- Evgeniia A Prokhorova
- Faculty of Basic Medicine, MV Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Alexey V Zamaraev
- Faculty of Basic Medicine, MV Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Gelina S Kopeina
- Faculty of Basic Medicine, MV Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Boris Zhivotovsky
- Faculty of Basic Medicine, MV Lomonosov Moscow State University, Moscow, 119991, Russia.
- Division of Toxicology, Institute of Environmental Medicine, Karolinska Institutet, Box 210, 17177, Stockholm, Sweden.
| | - Inna N Lavrik
- Faculty of Basic Medicine, MV Lomonosov Moscow State University, Moscow, 119991, Russia
- Department of Translational Inflammation, Institute of Experimental Internal Medicine, Otto von Guericke University, Magdeburg, Germany
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61
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Zheng J, Lang Y, Zhang Q, Cui D, Sun H, Jiang L, Chen Z, Zhang R, Gao Y, Tian W, Wu W, Tang J, Chen Z. Structure of human MDM2 complexed with RPL11 reveals the molecular basis of p53 activation. Genes Dev 2015. [PMID: 26220995 PMCID: PMC4526736 DOI: 10.1101/gad.261792.115] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Upon ribosomal stress, the central region of MDM2 is bound by ribosomal proteins, particularly ribosomal protein L11 (RPL11), leading to MDM2 inactivation and subsequent p53 activation. Zheng et al. solved the complex structure of human MDM2–RPL11 at 2.4 Å and show that formation of the MDM2–RPL11 complex induces substantial conformational changes in both proteins. The central region of MDM2 is critical for p53 activation and tumor suppression. Upon ribosomal stress, this region is bound by ribosomal proteins, particularly ribosomal protein L11 (RPL11), leading to MDM2 inactivation and subsequent p53 activation. Here, we solved the complex structure of human MDM2–RPL11 at 2.4 Å. MDM2 extensively interacts with RPL11 through an acidic domain and two zinc fingers. Formation of the MDM2–RPL11 complex induces substantial conformational changes in both proteins. RPL11, unable to bind MDM2 mutants, fails to induce the activation of p53 in cells. MDM2 mimics 28S rRNA binding to RPL11. The C4 zinc finger determines RPL11 binding to MDM2 but not its homolog, MDMX. Our results highlight the essential role of the RPL11–MDM2 interaction in p53 activation and tumor suppression and provide a structural basis for potential new anti-tumor drug development.
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Affiliation(s)
- Jiangge Zheng
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Yue Lang
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China; College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Qi Zhang
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Di Cui
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China; College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Haili Sun
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China; College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Lun Jiang
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Zhenhang Chen
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Rui Zhang
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China; College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Yina Gao
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Wenli Tian
- Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing 100093, China
| | - Wei Wu
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Jun Tang
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China; College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Zhongzhou Chen
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
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62
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Stabilization of SIRT7 deacetylase by viral oncoprotein HBx leads to inhibition of growth restrictive RPS7 gene and facilitates cellular transformation. Sci Rep 2015; 5:14806. [PMID: 26442981 PMCID: PMC4595800 DOI: 10.1038/srep14806] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 09/09/2015] [Indexed: 02/06/2023] Open
Abstract
Sirtuin-7 (SIRT7) deacetylase exhibits a high selectivity for acetylated H3K18 and has been implicated in the maintenance of malignant phenotype. However, it remains unclear if SIRT7 and H3K18ac play a role in the tumorigenic program driven by oncogenic viruses. We show that ectopically expressed HBx oncoprotein of hepatitis B virus promoted intracellular stability of SIRT7 by salvaging it from ubiquitin-mediated proteasomal degradation. HBx-dependent accumulation of SIRT7 favored H3K18 deacetylation and down-regulated the small ribosomal protein gene, RPS7, involved in cell death and DNA damage response. HBx facilitated the recruitment of SIRT7 to RPS7 promoter thus impeding H3K18ac occupancy and hindering RPS7 transcription. The antagonistic relationship between SIRT7 and RPS7 was also observed in the HBx transgenic mice, where elevated levels of SIRT7 protein were coincident with low levels of H3K18ac and RPS7. Strikingly, inhibition of cellular deubiquitinase activity restored RPS7 gene transcription. Further, depletion of endogenous SIRT7 led to decreased cell viability and transformation. The biological relevance of RPS7 suppression by HBx-SIRT7 axis was evident from ectopic expression of RPS7 which attenuated clonogenicity of cells. Thus, our findings suggest that SIRT7 is a critical regulator of HBx-driven oncogenic program, through its antagonistic impact on growth restrictive ribosomal protein RPS7.
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63
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Zheng J, Lang Y, Zhang Q, Cui D, Sun H, Jiang L, Chen Z, Zhang R, Gao Y, Tian W, Wu W, Tang J, Chen Z. Structure of human MDM2 complexed with RPL11 reveals the molecular basis of p53 activation. Genes Dev 2015. [PMID: 26220995 DOI: 10.1101/gad.261792] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/05/2023]
Abstract
The central region of MDM2 is critical for p53 activation and tumor suppression. Upon ribosomal stress, this region is bound by ribosomal proteins, particularly ribosomal protein L11 (RPL11), leading to MDM2 inactivation and subsequent p53 activation. Here, we solved the complex structure of human MDM2-RPL11 at 2.4 Å. MDM2 extensively interacts with RPL11 through an acidic domain and two zinc fingers. Formation of the MDM2-RPL11 complex induces substantial conformational changes in both proteins. RPL11, unable to bind MDM2 mutants, fails to induce the activation of p53 in cells. MDM2 mimics 28S rRNA binding to RPL11. The C4 zinc finger determines RPL11 binding to MDM2 but not its homolog, MDMX. Our results highlight the essential role of the RPL11-MDM2 interaction in p53 activation and tumor suppression and provide a structural basis for potential new anti-tumor drug development.
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Affiliation(s)
- Jiangge Zheng
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Yue Lang
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China; College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Qi Zhang
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Di Cui
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China; College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Haili Sun
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China; College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Lun Jiang
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Zhenhang Chen
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Rui Zhang
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China; College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Yina Gao
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Wenli Tian
- Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing 100093, China
| | - Wei Wu
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
| | - Jun Tang
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China; College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Zhongzhou Chen
- State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China
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Kruiswijk F, Labuschagne CF, Vousden KH. p53 in survival, death and metabolic health: a lifeguard with a licence to kill. Nat Rev Mol Cell Biol 2015; 16:393-405. [PMID: 26122615 DOI: 10.1038/nrm4007] [Citation(s) in RCA: 763] [Impact Index Per Article: 84.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The function of p53 as a tumour suppressor has been attributed to its ability to promote cell death or permanently inhibit cell proliferation. However, in recent years, it has become clear that p53 can also contribute to cell survival. p53 regulates various metabolic pathways, helping to balance glycolysis and oxidative phosphorylation, limiting the production of reactive oxygen species, and contributing to the ability of cells to adapt to and survive mild metabolic stresses. Although these activities may be integrated into the tumour suppressive functions of p53, deregulation of some elements of the p53-induced response might also provide tumours with a survival advantage.
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Affiliation(s)
- Flore Kruiswijk
- 1] Cancer Research UK Beatson Institute, Switchback Road, Glasgow G61 1BD, UK. [2]
| | | | - Karen H Vousden
- Cancer Research UK Beatson Institute, Switchback Road, Glasgow G61 1BD, UK
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Davis WJ, Lehmann PZ, Li W. Nuclear PI3K signaling in cell growth and tumorigenesis. Front Cell Dev Biol 2015; 3:24. [PMID: 25918701 PMCID: PMC4394695 DOI: 10.3389/fcell.2015.00024] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2014] [Accepted: 03/27/2015] [Indexed: 12/12/2022] Open
Abstract
The PI3K/Akt signaling pathway is a major driving force in a variety of cellular functions. Dysregulation of this pathway has been implicated in many human diseases including cancer. While the activity of the cytoplasmic PI3K/Akt pathway has been extensively studied, the functions of these molecules and their effector proteins within the nucleus are poorly understood. Harboring key cellular processes such as DNA replication and repair as well as nascent messenger RNA transcription, the nucleus provides a unique compartmental environment for protein–protein and protein–DNA/RNA interactions required for cell survival, growth, and proliferation. Here we summarize recent advances made toward elucidating the nuclear PI3K/Akt signaling cascade and its key components within the nucleus as they pertain to cell growth and tumorigenesis. This review covers the spatial and temporal localization of the major nuclear kinases having PI3K activities and the counteracting phosphatases as well as the role of nuclear PI3K/Akt signaling in mRNA processing and exportation, DNA replication and repair, ribosome biogenesis, cell survival, and tumorigenesis.
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Affiliation(s)
- William J Davis
- College of Medical Sciences, Washington State University Spokane, WA, USA
| | - Peter Z Lehmann
- College of Medical Sciences, Washington State University Spokane, WA, USA
| | - Weimin Li
- College of Medical Sciences, Washington State University Spokane, WA, USA
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66
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Lam YW, Trinkle-Mulcahy L. New insights into nucleolar structure and function. F1000PRIME REPORTS 2015; 7:48. [PMID: 26097721 PMCID: PMC4447046 DOI: 10.12703/p7-48] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The nucleolus is a non-membrane-bound nuclear organelle found in all eukaryotes. It is the quintessential ‘RNA-seeded’ nuclear body, forming around specific chromosomal features called nucleolar organizing regions that contain arrays of ribosomal DNA. Assembly is triggered by activation of RNA polymerase I-mediated transcription and regulated in mammalian cells in a cell cycle-dependent manner. Although the nucleolus is best known for its role in coordinating ribosome biogenesis, biochemical and proteomic analyses have revealed a much wider functional complexity than previously appreciated, including roles in cell cycle regulation, DNA damage sensing and repair, pre-mRNA processing, telomere metabolism, processing of non-coding RNAs, and coordination of the cellular response to various stresses. Despite these advances, much remains to be learned about the full range of biological processes that occur within, or involve, this organelle and how its assembly/disassembly and functional reorganization in response to various stimuli are regulated. Here, we review the impact of recent studies that provide major insights into these fundamental questions, and we highlight the therapeutic potential of targeting nucleolar pathways.
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Affiliation(s)
- Yun Wah Lam
- Department of Biology and Chemistry, City University of Hong KongTat Chee Avenue, KowloonHong Kong
| | - Laura Trinkle-Mulcahy
- Department of Cellular & Molecular Medicine and Ottawa Institute of Systems Biology, University of Ottawa451 Smyth Road, Ottawa, ON, K1H 8M5Canada
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Whole-genome RNAi screen highlights components of the endoplasmic reticulum/Golgi as a source of resistance to immunotoxin-mediated cytotoxicity. Proc Natl Acad Sci U S A 2015; 112:E1135-42. [PMID: 25713356 DOI: 10.1073/pnas.1501958112] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Immunotoxins (antibody-toxin fusion proteins) target surface antigens on cancer cells and kill these cells via toxin-mediated inhibition of protein synthesis. To identify genes controlling this process, an RNAi whole-genome screen (∼ 22,000 genes at three siRNAs per gene) was conducted via monitoring the cytotoxicity of the mesothelin-directed immunotoxin SS1P. SS1P, a Pseudomonas exotoxin-based immunotoxin, was chosen because it is now in clinical trials and has produced objective tumor regressions in patients. High and low concentrations of SS1P were chosen to allow for the identification of both mitigators and sensitizers. As expected, silencing known essential genes in the immunotoxin pathway, such as mesothelin, furin, KDEL receptor 2, or members of the diphthamide pathway, protected cells. Of greater interest was the observation that many RNAi targets increased immunotoxin sensitivity, indicating that these gene products normally contribute to inefficiencies in the killing pathway. Of the top sensitizers, many genes encode proteins that locate to either the endoplasmic reticulum (ER) or Golgi and are annotated as part of the secretory system. Genes related to the ER-associated degradation system were not among high-ranking mitigator or sensitizer candidates. However, the p97 inhibitor eeyarestatin 1 enhanced immunotoxin killing. Our results highlight potential targets for chemical intervention that could increase immunotoxin killing of cancer cells and enhance our understanding of toxin trafficking.
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Liang X, Liu Y, Xie L, Liu X, Wei Y, Zhou X, Zhang S. A ribosomal protein AgRPS3aE from halophilic Aspergillus glaucus confers salt tolerance in heterologous organisms. Int J Mol Sci 2015; 16:3058-70. [PMID: 25642759 PMCID: PMC4346880 DOI: 10.3390/ijms16023058] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 12/30/2014] [Accepted: 01/21/2015] [Indexed: 01/22/2023] Open
Abstract
High salt in soils is one of the abiotic stresses that significantly reduces crop yield, although saline lands are considered potential resources arable for agriculture. Currently, genetic engineering for enhancing salt tolerance is being tested as an efficient and viable strategy for crop improvement. We previously characterized a large subunit of the ribosomal protein RPL44, which is involved in osmotic stress in the extremely halophilic fungus Aspergillus glaucus. Here, we screened another ribosomal protein (AgRPS3aE) that also produced high-salt tolerance in yeast. Bioinformatics analysis indicated that AgRPS3aE encodes a 29.2 kDa small subunit of a ribosomal protein belonging to the RPS3Ae family in eukaryotes. To further confirm its protective function against salinity, we expressed AgRPS3aE in three heterologous systems, the filamentous fungus Magnaporthe oryzae and two model plants Arabidopsis and tobacco. Overexpression of AgRPS3aE in all tested transformants significantly alleviated stress symptoms compared with controls, suggesting that AgRPS3aE functions not only in fungi but also in plants. Considering that ribosomal proteins are housekeeping components in organisms from prokaryotes to eukaryotes, we propose that AgRPS3aE is one of the optimal genes for improving high-salt tolerance in crops.
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Affiliation(s)
- Xilong Liang
- College of Plant Sciences, Jilin University, Changchun 130062, China.
| | - Yiling Liu
- College of Plant Sciences, Jilin University, Changchun 130062, China.
| | - Lixia Xie
- College of Plant Sciences, Jilin University, Changchun 130062, China.
| | - Xiaodan Liu
- College of Plant Sciences, Jilin University, Changchun 130062, China.
| | - Yi Wei
- College of Plant Sciences, Jilin University, Changchun 130062, China.
| | - Xiaoyang Zhou
- College of Plant Sciences, Jilin University, Changchun 130062, China.
| | - Shihong Zhang
- College of Plant Sciences, Jilin University, Changchun 130062, China.
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