1
|
Theophanous A, Christodoulou A, Mattheou C, Sibai DS, Moss T, Santama N. Transcription factor UBF depletion in mouse cells results in downregulation of both downstream and upstream elements of the rRNA transcription network. J Biol Chem 2023; 299:105203. [PMID: 37660911 PMCID: PMC10558777 DOI: 10.1016/j.jbc.2023.105203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 08/20/2023] [Accepted: 08/24/2023] [Indexed: 09/05/2023] Open
Abstract
Transcription/processing of the ribosomal RNA (rRNA) precursor, as part of ribosome biosynthesis, is intensively studied and characterized in eukaryotic cells. Here, we constructed shRNA-based mouse cell lines partially silenced for the Upstream Binding Factor UBF, the master regulator of rRNA transcription and organizer of open rDNA chromatin. Full Ubf silencing in vivo is not viable, and these new tools allow further characterization of rRNA transcription and its coordination with cellular signaling. shUBF cells display cell cycle G1 delay and reduced 47S rRNA precursor and 28S rRNA at baseline and serum-challenged conditions. Growth-related mTOR signaling is downregulated with the fractions of active phospho-S6 Kinase and pEIF4E translation initiation factor reduced, similar to phosphorylated cell cycle regulator retinoblastoma, pRB, positive regulator of UBF availability/rRNA transcription. Additionally, we find transcription-competent pUBF (Ser484) severely restricted and its interacting initiation factor RRN3 reduced and responsive to extracellular cues. Furthermore, fractional UBF occupancy on the rDNA unit is decreased in shUBF, and expression of major factors involved in different aspects of rRNA transcription is severely downregulated by UBF depletion. Finally, we observe reduced RNA Pol1 occupancy over rDNA promoter sequences and identified unexpected regulation of RNA Pol1 expression, relative to serum availability and under UBF silencing, suggesting that regulation of rRNA transcription may not be restricted to modulation of Pol1 promoter binding/elongation rate. Overall, this work reveals that UBF depletion has a critical downstream and upstream impact on the whole network orchestrating rRNA transcription in mammalian cells.
Collapse
Affiliation(s)
- Andria Theophanous
- Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus
| | | | | | - Dany S Sibai
- Laboratory of Growth and Development, St-Patrick Research Group in Basic Oncology, Cancer Division of the Quebec University Hospital Research Centre, Quebec, Canada; Department of Molecular Biology, Medical Biochemistry and Pathology, Faculty of Medicine, Laval University, Quebec, Canada
| | - Tom Moss
- Laboratory of Growth and Development, St-Patrick Research Group in Basic Oncology, Cancer Division of the Quebec University Hospital Research Centre, Quebec, Canada; Department of Molecular Biology, Medical Biochemistry and Pathology, Faculty of Medicine, Laval University, Quebec, Canada
| | - Niovi Santama
- Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus.
| |
Collapse
|
2
|
Rowell MC, Deschênes-Simard X, Lopes-Paciencia S, Le Calvé B, Kalegari P, Mignacca L, Fernandez-Ruiz A, Guillon J, Lessard F, Bourdeau V, Igelmann S, Duman AM, Stanom Y, Kottakis F, Deshpande V, Krizhanovsky V, Bardeesy N, Ferbeyre G. Targeting ribosome biogenesis reinforces ERK-dependent senescence in pancreatic cancer. Cell Cycle 2023; 22:2172-2193. [PMID: 37942963 PMCID: PMC10732607 DOI: 10.1080/15384101.2023.2278945] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 10/30/2023] [Indexed: 11/10/2023] Open
Abstract
Pancreatic adenocarcinomas (PDAC) often possess mutations in K-Ras that stimulate the ERK pathway. Aberrantly high ERK activation triggers oncogene-induced senescence, which halts tumor progression. Here we report that low-grade pancreatic intraepithelial neoplasia displays very high levels of phospho-ERK consistent with a senescence response. However, advanced lesions that have circumvented the senescence barrier exhibit lower phospho-ERK levels. Restoring ERK hyperactivation in PDAC using activated RAF leads to ERK-dependent growth arrest with senescence biomarkers. ERK-dependent senescence in PDAC was characterized by a nucleolar stress response including a selective depletion of nucleolar phosphoproteins and intranucleolar foci containing RNA polymerase I designated as senescence-associated nucleolar foci (SANF). Accordingly, combining ribosome biogenesis inhibitors with ERK hyperactivation reinforced the senescence response in PDAC cells. Notably, comparable mechanisms were observed upon treatment with the platinum-based chemotherapy regimen FOLFIRINOX, currently a first-line treatment option for PDAC. We thus suggest that drugs targeting ribosome biogenesis can improve the senescence anticancer response in pancreatic cancer.
Collapse
Affiliation(s)
- MC. Rowell
- Département de Biochimie et Médecine Moléculaire, Centre de recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), Montreal, QC, Canada
| | - X. Deschênes-Simard
- Département de Biochimie et Médecine Moléculaire, Maisonneuve-Rosemont Hospital, Université de Montréal, Montreal, QC, Canada
| | - S. Lopes-Paciencia
- Département de Biochimie et Médecine Moléculaire, Centre de recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), Montreal, QC, Canada
| | - B. Le Calvé
- Département de Biochimie et Médecine Moléculaire, Université de Montréal, QC, Canada
| | - P. Kalegari
- Département de Biochimie et Médecine Moléculaire, Centre de recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), Montreal, QC, Canada
| | - L. Mignacca
- Département de Biochimie et Médecine Moléculaire, Université de Montréal, QC, Canada
| | - A. Fernandez-Ruiz
- Département de Biochimie et Médecine Moléculaire, Centre de recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), Montreal, QC, Canada
| | - J. Guillon
- Département de Biochimie et Médecine Moléculaire, Centre de recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), Montreal, QC, Canada
| | - F. Lessard
- Département de Biochimie et Médecine Moléculaire, Université de Montréal, QC, Canada
- Laboratory of Growth and Development, St-Patrick Research Group in Basic Oncology, Cancer Division of the Quebec University Research Centre, Canada, Present
| | - V. Bourdeau
- Département de Biochimie et Médecine Moléculaire, Université de Montréal, QC, Canada
| | - S Igelmann
- Département de Biochimie et Médecine Moléculaire, Centre de recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), Montreal, QC, Canada
- Département de Biochimie et Médecine Moléculaire, Université de Montréal, QC, Canada
| | - AM. Duman
- Département de Biochimie et Médecine Moléculaire, Centre de recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), Montreal, QC, Canada
| | - Y. Stanom
- Département de Biochimie et Médecine Moléculaire, Université de Montréal, QC, Canada
| | - F. Kottakis
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Boston, MA, USA
| | - V. Deshpande
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Boston, MA, USA
| | - V. Krizhanovsky
- Department of Molecular Cell Biology, The Weizmann Institute of Science, Rehovot, Israel
| | - N. Bardeesy
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Boston, MA, USA
| | - G. Ferbeyre
- Département de Biochimie et Médecine Moléculaire, Centre de recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), Montreal, QC, Canada
- Département de Biochimie et Médecine Moléculaire, Université de Montréal, QC, Canada
| |
Collapse
|
3
|
Shahab M, Zheng G, Khan A, Wei D, Novikov AS. Machine Learning-Based Virtual Screening and Molecular Simulation Approaches Identified Novel Potential Inhibitors for Cancer Therapy. Biomedicines 2023; 11:2251. [PMID: 37626747 PMCID: PMC10452548 DOI: 10.3390/biomedicines11082251] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 08/07/2023] [Accepted: 08/08/2023] [Indexed: 08/27/2023] Open
Abstract
Cyclin-dependent kinase 2 (CDK2) is a promising target for cancer treatment, developing new effective CDK2 inhibitors is of great significance in anticancer therapy. The involvement of CDK2 in tumorigenesis has been debated, but recent evidence suggests that specifically inhibiting CDK2 could be beneficial in treating certain tumors. This approach remains attractive in the development of anticancer drugs. Several small-molecule inhibitors targeting CDK2 have reached clinical trials, but a selective inhibitor for CDK2 is yet to be discovered. In this study, we conducted machine learning-based drug designing to search for a drug candidate for CDK2. Machine learning models, including k-NN, SVM, RF, and GNB, were created to detect active and inactive inhibitors for a CDK2 drug target. The models were assessed using 10-fold cross-validation to ensure their accuracy and reliability. These methods are highly suitable for classifying compounds as either active or inactive through the virtual screening of extensive compound libraries. Subsequently, machine learning techniques were employed to analyze the test dataset obtained from the zinc database. A total of 25 compounds with 98% accuracy were predicted as active against CDK2. These compounds were docked into CDK2's active site. Finally, three compounds were selected based on good docking score, and, along with a reference compound, underwent MD simulation. The Gaussian naïve Bayes model yielded superior results compared to other models. The top three hits exhibited enhanced stability and compactness compared to the reference compound. In conclusion, our study provides valuable insights for identifying and refining lead compounds as CDK2 inhibitors.
Collapse
Affiliation(s)
- Muhammad Shahab
- State Key Laboratories of Chemical Resources Engineering, Beijing University of Chemical Technology, Beijing 100029, China;
| | - Guojun Zheng
- State Key Laboratories of Chemical Resources Engineering, Beijing University of Chemical Technology, Beijing 100029, China;
| | - Abbas Khan
- Department of Bioinformatics and Biological Statistics, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China; (A.K.); (D.W.)
| | - Dongqing Wei
- Department of Bioinformatics and Biological Statistics, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China; (A.K.); (D.W.)
| | - Alexander S. Novikov
- Institute of Chemistry, Saint Petersburg State University, Saint Petersburg 199034, Russia
- Research Institute of Chemistry, Peoples’ Friendship University of Russia (RUDN University), Moscow 117198, Russia
| |
Collapse
|
4
|
Ballmer D, Tardat M, Ortiz R, Graff-Meyer A, Ozonov E, Genoud C, Peters A, Fanourgakis G. HP1 proteins regulate nucleolar structure and function by secluding pericentromeric constitutive heterochromatin. Nucleic Acids Res 2022; 51:117-143. [PMID: 36533441 PMCID: PMC9841413 DOI: 10.1093/nar/gkac1159] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 10/29/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022] Open
Abstract
Nucleoli are nuclear compartments regulating ribosome biogenesis and cell growth. In embryonic stem cells (ESCs), nucleoli containing transcriptionally active ribosomal genes are spatially separated from pericentromeric satellite repeat sequences packaged in largely repressed constitutive heterochromatin (PCH). To date, mechanisms underlying such nuclear partitioning and the physiological relevance thereof are unknown. Here we show that repressive chromatin at PCH ensures structural integrity and function of nucleoli during cell cycle progression. Loss of heterochromatin proteins HP1α and HP1β causes deformation of PCH, with reduced H3K9 trimethylation (H3K9me3) and HP1γ levels, absence of H4K20me3 and upregulated major satellites expression. Spatially, derepressed PCH aberrantly associates with nucleoli accumulating severe morphological defects during S/G2 cell cycle progression. Hp1α/β deficiency reduces cell proliferation, ribosomal RNA biosynthesis and mobility of Nucleophosmin, a major nucleolar component. Nucleolar integrity and function require HP1α/β proteins to be recruited to H3K9me3-marked PCH and their ability to dimerize. Correspondingly, ESCs deficient for both Suv39h1/2 H3K9 HMTs display similar nucleolar defects. In contrast, Suv4-20h1/2 mutant ESCs lacking H4K20me3 at PCH do not. Suv39h1/2 and Hp1α/β deficiency-induced nucleolar defects are reminiscent of those defining human ribosomopathy disorders. Our results reveal a novel role for SUV39H/HP1-marked repressive constitutive heterochromatin in regulating integrity, function and physiology of nucleoli.
Collapse
Affiliation(s)
- Daniel Ballmer
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland,Faculty of Sciences, University of Basel, 4056 Basel, Switzerland
| | - Mathieu Tardat
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Raphael Ortiz
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Alexandra Graff-Meyer
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Evgeniy A Ozonov
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Christel Genoud
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | | | - Grigorios Fanourgakis
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| |
Collapse
|
5
|
Zhang J, Gan Y, Li H, Yin J, He X, Lin L, Xu S, Fang Z, Kim BW, Gao L, Ding L, Zhang E, Ma X, Li J, Li L, Xu Y, Horne D, Xu R, Yu H, Gu Y, Huang W. Inhibition of the CDK2 and Cyclin A complex leads to autophagic degradation of CDK2 in cancer cells. Nat Commun 2022; 13:2835. [PMID: 35595767 PMCID: PMC9122913 DOI: 10.1038/s41467-022-30264-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Accepted: 04/23/2022] [Indexed: 12/20/2022] Open
Abstract
Cyclin-dependent kinase 2 (CDK2) complex is significantly over-activated in many cancers. While it makes CDK2 an attractive target for cancer therapy, most inhibitors against CDK2 are ATP competitors that are either nonspecific or highly toxic, and typically fail clinical trials. One alternative approach is to develop non-ATP competitive inhibitors; they disrupt interactions between CDK2 and either its partners or substrates, resulting in specific inhibition of CDK2 activities. In this report, we identify two potential druggable pockets located in the protein-protein interaction interface (PPI) between CDK2 and Cyclin A. To target the potential druggable pockets, we perform a LIVS in silico screening of a library containing 1925 FDA approved drugs. Using this approach, homoharringtonine (HHT) shows high affinity to the PPI and strongly disrupts the interaction between CDK2 and cyclins. Further, we demonstrate that HHT induces autophagic degradation of the CDK2 protein via tripartite motif 21 (Trim21) in cancer cells, which is confirmed in a leukemia mouse model and in human primary leukemia cells. These results thus identify an autophagic degradation mechanism of CDK2 protein and provide a potential avenue towards treating CDK2-dependent cancers. CDK2 can drive the proliferation of cancer cells. Here, the authors screened for a non-ATP competitive inhibitor of the CDK2/cylinA complex and find that Homoharringtonine can disrupt the complex and promote the degradation of CDK2.
Collapse
Affiliation(s)
- Jiawei Zhang
- Cancer Institute (Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education), Second Affiliated Hospital, School of Medicine, Zhejiang University, 310009, Hangzhou, China.,Molecular and Cellular Biology of Cancer Program & Department of Diabetes Complications and Metabolism, Arthur Riggs Diabetes & Metabolism Research Institute, Beckman Research Institute, City of Hope, Duarte, CA, 91010, USA
| | - Yichao Gan
- Cancer Institute (Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education), Second Affiliated Hospital, School of Medicine, Zhejiang University, 310009, Hangzhou, China.,Institute of Genetics, Zhejiang University and Department of Human Genetics, Zhejiang University School of Medicine, 310058, Hangzhou, Zhejiang, China
| | - Hongzhi Li
- Department of Molecular Medicine, Beckman Research Institute, City of Hope, Duarte, CA, 91010, USA
| | - Jie Yin
- Cancer Institute (Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education), Second Affiliated Hospital, School of Medicine, Zhejiang University, 310009, Hangzhou, China.,Institute of Genetics, Zhejiang University and Department of Human Genetics, Zhejiang University School of Medicine, 310058, Hangzhou, Zhejiang, China
| | - Xin He
- Division of Hematopoietic Stem Cell & Leukemia Research, Beckman Research Institute, City of Hope, Duarte, CA, 91010, USA
| | - Liming Lin
- Cancer Institute (Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education), Second Affiliated Hospital, School of Medicine, Zhejiang University, 310009, Hangzhou, China.,Department of Hematology, Second Affiliated Hospital, School of Medicine, Zhejiang University, 310009, Hangzhou, China
| | - Senlin Xu
- Molecular and Cellular Biology of Cancer Program & Department of Diabetes Complications and Metabolism, Arthur Riggs Diabetes & Metabolism Research Institute, Beckman Research Institute, City of Hope, Duarte, CA, 91010, USA.,Irell & Manella Graduate School of Biological Sciences, Beckman Research Institute, City of Hope, Duarte, CA, 91010, USA
| | - Zhipeng Fang
- Molecular and Cellular Biology of Cancer Program & Department of Diabetes Complications and Metabolism, Arthur Riggs Diabetes & Metabolism Research Institute, Beckman Research Institute, City of Hope, Duarte, CA, 91010, USA
| | - Byung-Wook Kim
- Molecular and Cellular Biology of Cancer Program & Department of Diabetes Complications and Metabolism, Arthur Riggs Diabetes & Metabolism Research Institute, Beckman Research Institute, City of Hope, Duarte, CA, 91010, USA
| | - Lina Gao
- Molecular and Cellular Biology of Cancer Program & Department of Diabetes Complications and Metabolism, Arthur Riggs Diabetes & Metabolism Research Institute, Beckman Research Institute, City of Hope, Duarte, CA, 91010, USA
| | - Lili Ding
- Molecular and Cellular Biology of Cancer Program & Department of Diabetes Complications and Metabolism, Arthur Riggs Diabetes & Metabolism Research Institute, Beckman Research Institute, City of Hope, Duarte, CA, 91010, USA
| | - Eryun Zhang
- Molecular and Cellular Biology of Cancer Program & Department of Diabetes Complications and Metabolism, Arthur Riggs Diabetes & Metabolism Research Institute, Beckman Research Institute, City of Hope, Duarte, CA, 91010, USA
| | - Xiaoxiao Ma
- Molecular and Cellular Biology of Cancer Program & Department of Diabetes Complications and Metabolism, Arthur Riggs Diabetes & Metabolism Research Institute, Beckman Research Institute, City of Hope, Duarte, CA, 91010, USA
| | - Junfeng Li
- Department of Translational Research & Cellular Therapeutics, Beckman Research Institute of the City of Hope, Duarte, CA, 91010, USA
| | - Ling Li
- Division of Hematopoietic Stem Cell & Leukemia Research, Beckman Research Institute, City of Hope, Duarte, CA, 91010, USA
| | - Yang Xu
- Cancer Institute (Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education), Second Affiliated Hospital, School of Medicine, Zhejiang University, 310009, Hangzhou, China.,Department of Hematology, Second Affiliated Hospital, School of Medicine, Zhejiang University, 310009, Hangzhou, China
| | - David Horne
- Department of Molecular Medicine, Beckman Research Institute, City of Hope, Duarte, CA, 91010, USA
| | - Rongzhen Xu
- Cancer Institute (Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education), Second Affiliated Hospital, School of Medicine, Zhejiang University, 310009, Hangzhou, China.,Department of Hematology, Second Affiliated Hospital, School of Medicine, Zhejiang University, 310009, Hangzhou, China
| | - Hua Yu
- Department of Immuno-Oncology, Beckman Research Institute of the City of Hope, Duarte, CA, 91010, USA
| | - Ying Gu
- Cancer Institute (Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education), Second Affiliated Hospital, School of Medicine, Zhejiang University, 310009, Hangzhou, China. .,Institute of Genetics, Zhejiang University and Department of Human Genetics, Zhejiang University School of Medicine, 310058, Hangzhou, Zhejiang, China. .,Zhejiang Provincial Key Lab of Genetic and Developmental Disorder, 310058, Hangzhou, Zhejiang, China. .,Liangzhu Laboratory, Zhejiang University Medical Center, 311121, Hangzhou, Zhejiang, China.
| | - Wendong Huang
- Molecular and Cellular Biology of Cancer Program & Department of Diabetes Complications and Metabolism, Arthur Riggs Diabetes & Metabolism Research Institute, Beckman Research Institute, City of Hope, Duarte, CA, 91010, USA. .,Irell & Manella Graduate School of Biological Sciences, Beckman Research Institute, City of Hope, Duarte, CA, 91010, USA.
| |
Collapse
|
6
|
Shaikh J, Patel K, Khan T. Advances in Pyrazole Based Scaffold as Cyclin-Dependent Kinase 2 Inhibitors for the Treatment of Cancer. Mini Rev Med Chem 2021; 22:1197-1215. [PMID: 34711160 DOI: 10.2174/1389557521666211027104957] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 05/27/2021] [Accepted: 08/04/2021] [Indexed: 11/22/2022]
Abstract
The transformation of a normal cell into a tumor cell is one of the initial steps in cell cycle deregulation. The cell cycle is regulated by cyclin-dependent kinases (CDKs) that belong to the protein kinase family. CDK2 is an enchanting target for specific genotypes tumors since cyclin E is selective for CDK2 and the deregulation of specific cancer forms. Thus, CDKs inhibitor specifically CDK2/cyclin A-E has the potential to be a valid cancer target as per the currently undergoing clinical trials. Mostly pyrazole scaffolds have shown selectivity and potency for CDK2 inhibitors. This review demonstrates pyrazole and pyrazole fused with other heterocyclic rings for anti-proliferative activity. Based on the in vitro and molecular docking studies, the IC50 value of various hybrids is revealed to display the most potent analogs for CDK2 inhibition. Thus, the review emphasizes various lead analogs of pyrazole hybrids which can be found to be very potent and selective for anti-cancer drugs.
Collapse
Affiliation(s)
- Jahara Shaikh
- Department of Pharmaceutical Chemistry & Quality Assurance, SVKM'S Dr. Bhanuben Nanavati College of Pharmacy, Vile Parle (W), Mumbai-56. India
| | - Kavitkumar Patel
- Department of Pharmaceutical Chemistry & Quality Assurance, SVKM'S Dr. Bhanuben Nanavati College of Pharmacy, Vile Parle (W), Mumbai-56. India
| | - Tabassum Khan
- Department of Pharmaceutical Chemistry & Quality Assurance, SVKM'S Dr. Bhanuben Nanavati College of Pharmacy, Vile Parle (W), Mumbai-56. India
| |
Collapse
|
7
|
Antagonising Chromatin Remodelling Activities in the Regulation of Mammalian Ribosomal Transcription. Genes (Basel) 2021; 12:genes12070961. [PMID: 34202617 PMCID: PMC8303148 DOI: 10.3390/genes12070961] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 06/16/2021] [Accepted: 06/19/2021] [Indexed: 12/29/2022] Open
Abstract
Ribosomal transcription constitutes the major energy consuming process in cells and is regulated in response to proliferation, differentiation and metabolic conditions by several signalling pathways. These act on the transcription machinery but also on chromatin factors and ncRNA. The many ribosomal gene repeats are organised in a number of different chromatin states; active, poised, pseudosilent and repressed gene repeats. Some of these chromatin states are unique to the 47rRNA gene repeat and do not occur at other locations in the genome, such as the active state organised with the HMG protein UBF whereas other chromatin state are nucleosomal, harbouring both active and inactive histone marks. The number of repeats in a certain state varies on developmental stage and cell type; embryonic cells have more rRNA gene repeats organised in an open chromatin state, which is replaced by heterochromatin during differentiation, establishing different states depending on cell type. The 47S rRNA gene transcription is regulated in different ways depending on stimulus and chromatin state of individual gene repeats. This review will discuss the present knowledge about factors involved, such as chromatin remodelling factors NuRD, NoRC, CSB, B-WICH, histone modifying enzymes and histone chaperones, in altering gene expression and switching chromatin states in proliferation, differentiation, metabolic changes and stress responses.
Collapse
|
8
|
The Ribosomal Gene Loci-The Power behind the Throne. Genes (Basel) 2021; 12:genes12050763. [PMID: 34069807 PMCID: PMC8157237 DOI: 10.3390/genes12050763] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 05/12/2021] [Accepted: 05/14/2021] [Indexed: 12/20/2022] Open
Abstract
Nucleoli form around actively transcribed ribosomal RNA (rRNA) genes (rDNA), and the morphology and location of nucleolus-associated genomic domains (NADs) are linked to the RNA Polymerase I (Pol I) transcription status. The number of rDNA repeats (and the proportion of actively transcribed rRNA genes) is variable between cell types, individuals and disease state. Substantial changes in nucleolar morphology and size accompanied by concomitant changes in the Pol I transcription rate have long been documented during normal cell cycle progression, development and malignant transformation. This demonstrates how dynamic the nucleolar structure can be. Here, we will discuss how the structure of the rDNA loci, the nucleolus and the rate of Pol I transcription are important for dynamic regulation of global gene expression and genome stability, e.g., through the modulation of long-range genomic interactions with the suppressive NAD environment. These observations support an emerging paradigm whereby the rDNA repeats and the nucleolus play a key regulatory role in cellular homeostasis during normal development as well as disease, independent of their role in determining ribosome capacity and cellular growth rates.
Collapse
|
9
|
Ladelfa MF, Peche LY, Amato GE, Escalada MC, Zampieri S, Pascucci FA, Benevento AF, Do Porto DF, Dardis A, Schneider C, Monte M. Expression of the tumor-expressed protein MageB2 enhances rRNA transcription. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2021; 1868:119015. [PMID: 33741433 DOI: 10.1016/j.bbamcr.2021.119015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 02/22/2021] [Accepted: 03/12/2021] [Indexed: 11/17/2022]
Abstract
An essential requirement for cells to sustain a high proliferating rate is to be paired with enhanced protein synthesis through the production of ribosomes. For this reason, part of the growth-factor signaling pathways, are devoted to activate ribosome biogenesis. Enhanced production of ribosomes is a hallmark in cancer cells, which is boosted by different mechanisms. Here we report that the nucleolar tumor-protein MageB2, whose expression is associated with cell proliferation, also participates in ribosome biogenesis. Studies carried out in both siRNA-mediated MageB2 silenced cells and CRISPR/CAS9-mediated MageB2 knockout (KO) cells showed that its expression is linked to rRNA transcription increase independently of the cell proliferation status. Mechanistically, MageB2 interacts with phospho-UBF, a protein which causes the recruitment of RNA Pol I pre-initiation complex required for rRNA transcription. In addition, cells expressing MageB2 displays enhanced phospho-UBF occupancy at the rDNA gene promoter. Proteomic studies performed in MageB2 KO cells revealed impairment in ribosomal protein (RPs) content. Functionally, enhancement in rRNA production in MageB2 expressing cells, was directly associated with an increased dynamic in protein synthesis. Altogether our results unveil a novel function for a tumor-expressed protein from the MAGE-I family. Findings reported here suggest that nucleolar MageB2 might play a role in enhancing ribosome biogenesis as part of its repertoire to support cancer cell proliferation.
Collapse
Affiliation(s)
- María Fátima Ladelfa
- Lab. Oncología Molecular, Departamento de Química Biológica, IQUIBICEN-UBA/CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Leticia Yamila Peche
- Laboratorio Nazionale del Consorzio Interuniversitario per le Biotecnologie, Area Science Park, Trieste, Italy
| | - Gastón Ezequiel Amato
- Lab. Oncología Molecular, Departamento de Química Biológica, IQUIBICEN-UBA/CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Micaela Carolina Escalada
- Lab. Oncología Molecular, Departamento de Química Biológica, IQUIBICEN-UBA/CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Stefania Zampieri
- Centro di Coordinamento Regionale per le Malattie Rare, Ospedale Universitario Santa Maria Della Misericordia, Udine, Italy
| | - Franco Andrés Pascucci
- Lab. Oncología Molecular, Departamento de Química Biológica, IQUIBICEN-UBA/CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Andres Fernandez Benevento
- Plataforma de Bioinformática Argentina, Instituto de Cálculo, Pabellón 2, Ciudad Universitaria, Facultad de Ciencias Exactas y Naturales, UBA, Buenos Aires, Argentina
| | - Dario Fernandez Do Porto
- Plataforma de Bioinformática Argentina, Instituto de Cálculo, Pabellón 2, Ciudad Universitaria, Facultad de Ciencias Exactas y Naturales, UBA, Buenos Aires, Argentina
| | - Andrea Dardis
- Centro di Coordinamento Regionale per le Malattie Rare, Ospedale Universitario Santa Maria Della Misericordia, Udine, Italy
| | - Claudio Schneider
- Laboratorio Nazionale del Consorzio Interuniversitario per le Biotecnologie, Area Science Park, Trieste, Italy; Dipartimento di Scienze e Tecnologie Biomediche, Università di Udine, p.le Kolbe 4, Udine, Italy
| | - Martin Monte
- Lab. Oncología Molecular, Departamento de Química Biológica, IQUIBICEN-UBA/CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.
| |
Collapse
|
10
|
Solsona R, Pavlin L, Bernardi H, Sanchez AMJ. Molecular Regulation of Skeletal Muscle Growth and Organelle Biosynthesis: Practical Recommendations for Exercise Training. Int J Mol Sci 2021; 22:2741. [PMID: 33800501 PMCID: PMC7962973 DOI: 10.3390/ijms22052741] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 03/04/2021] [Accepted: 03/04/2021] [Indexed: 12/18/2022] Open
Abstract
The regulation of skeletal muscle mass and organelle homeostasis is dependent on the capacity of cells to produce proteins and to recycle cytosolic portions. In this investigation, the mechanisms involved in skeletal muscle mass regulation-especially those associated with proteosynthesis and with the production of new organelles-are presented. Thus, the critical roles of mammalian/mechanistic target of rapamycin complex 1 (mTORC1) pathway and its regulators are reviewed. In addition, the importance of ribosome biogenesis, satellite cells involvement, myonuclear accretion, and some major epigenetic modifications related to protein synthesis are discussed. Furthermore, several studies conducted on the topic of exercise training have recognized the central role of both endurance and resistance exercise to reorganize sarcomeric proteins and to improve the capacity of cells to build efficient organelles. The molecular mechanisms underlying these adaptations to exercise training are presented throughout this review and practical recommendations for exercise prescription are provided. A better understanding of the aforementioned cellular pathways is essential for both healthy and sick people to avoid inefficient prescriptions and to improve muscle function with emergent strategies (e.g., hypoxic training). Finally, current limitations in the literature and further perspectives, notably on epigenetic mechanisms, are provided to encourage additional investigations on this topic.
Collapse
Affiliation(s)
- Robert Solsona
- Laboratoire Interdisciplinaire Performance Santé Environnement de Montagne (LIPSEM), Faculty of Sports Sciences, University of Perpignan Via Domitia, UR 4640, 7 Avenue Pierre de Coubertin, 66120 Font-Romeu, France;
| | - Laura Pavlin
- DMEM, University of Montpellier, INRAE UMR866, 2 Place Pierre Viala, 34060 Montpellier, France; (L.P.); (H.B.)
| | - Henri Bernardi
- DMEM, University of Montpellier, INRAE UMR866, 2 Place Pierre Viala, 34060 Montpellier, France; (L.P.); (H.B.)
| | - Anthony MJ Sanchez
- Laboratoire Interdisciplinaire Performance Santé Environnement de Montagne (LIPSEM), Faculty of Sports Sciences, University of Perpignan Via Domitia, UR 4640, 7 Avenue Pierre de Coubertin, 66120 Font-Romeu, France;
| |
Collapse
|
11
|
Yuan X, Zhang W, He Y, Yuan J, Song D, Chen H, Qin W, Qian X, Yu H, Guo Z. Proteomic analysis of cisplatin- and oxaliplatin-induced phosphorylation in proteins bound to Pt-DNA adducts. Metallomics 2020; 12:1834-1840. [PMID: 33151228 DOI: 10.1039/d0mt00194e] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Cisplatin and oxaliplatin are widely used anti-tumour chemotherapeutic agents with different spectra of activity. The therapeutic efficacy of such platinum-based drug is believed to, at least in part, result from formation of Pt-DNA adducts, followed by DNA damage response and ultimately apoptosis. However, it remains unclear whether these DNA lesions caused by cisplatin and oxaliplatin elicit distinct reactions in cellular signaling pathways. Here, a label-free comparative proteomic study was performed to profile the protein phosphorylation patterns using Pt-DNA probes with different ligand identities and geometries. Phosphorylated proteins recognizing different cisplatin- and oxaliplatin-DNA lesions were enriched and analyzed on LC-MS/MS. Proteomic analysis revealed that cisplatin mainly affected proteins involved in mRNA processing, while chromatin organization and rRNA processing are two major biological processes influenced by oxaliplatin. Changes to site-specific phosphorylation levels of two proteins YBX1 and UBF1 were also validated by Western blotting. In particular, platinum drug treatment in colon and liver cancer cell lines down-regulated S484 phosphorylation of UBF1, which is an essential transcription factor responsible for ribosomal DNA transcription activation, implying that inhibition of ribosome biogenesis might be involved in the cytotoxic mechanism of platinum drugs. Collectively, these results directly reflected distinct protein phosphorylation patterns triggered by cisplatin and oxaliplatin, and could also provide valuable resources for future mechanistic studies of platinum-based anti-tumour agents.
Collapse
Affiliation(s)
- Xin Yuan
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Chemistry and Biomedicine Innovation Center, Nanjing University, Nanjing 210023, P. R. China.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Sorino C, Catena V, Bruno T, De Nicola F, Scalera S, Bossi G, Fabretti F, Mano M, De Smaele E, Fanciulli M, Iezzi S. Che-1/AATF binds to RNA polymerase I machinery and sustains ribosomal RNA gene transcription. Nucleic Acids Res 2020; 48:5891-5906. [PMID: 32421830 PMCID: PMC7293028 DOI: 10.1093/nar/gkaa344] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 04/21/2020] [Accepted: 04/24/2020] [Indexed: 02/06/2023] Open
Abstract
Originally identified as an RNA polymerase II interactor, Che-1/AATF (Che-1) has now been recognized as a multifunctional protein involved in cell-cycle regulation and cancer progression, as well as apoptosis inhibition and response to stress. This protein displays a peculiar nucleolar localization and it has recently been implicated in pre-rRNA processing and ribosome biogenesis. Here, we report the identification of a novel function of Che-1 in the regulation of ribosomal RNA (rRNA) synthesis, in both cancer and normal cells. We demonstrate that Che-1 interacts with RNA polymerase I and nucleolar upstream binding factor (UBF) and promotes RNA polymerase I-dependent transcription. Furthermore, this protein binds to the rRNA gene (rDNA) promoter and modulates its epigenetic state by contrasting the recruitment of HDAC1. Che-1 downregulation affects RNA polymerase I and UBF recruitment on rDNA and leads to reducing rDNA promoter activity and 47S pre-rRNA production. Interestingly, Che-1 depletion induces abnormal nucleolar morphology associated with re-distribution of nucleolar proteins. Finally, we show that upon DNA damage Che-1 re-localizes from rDNA to TP53 gene promoter to induce cell-cycle arrest. This previously uncharacterized function of Che-1 confirms the important role of this protein in the regulation of ribosome biogenesis, cellular proliferation and response to stress.
Collapse
Affiliation(s)
- Cristina Sorino
- SAFU Laboratory, Department of Research, Advanced Diagnostics and Technological Innovation, Translational Research Area, IRCCS Regina Elena National Cancer Institute, 00144 Rome, Italy.,Department of Experimental Medicine, Sapienza-University of Rome, 00161 Rome, Italy
| | - Valeria Catena
- SAFU Laboratory, Department of Research, Advanced Diagnostics and Technological Innovation, Translational Research Area, IRCCS Regina Elena National Cancer Institute, 00144 Rome, Italy
| | - Tiziana Bruno
- SAFU Laboratory, Department of Research, Advanced Diagnostics and Technological Innovation, Translational Research Area, IRCCS Regina Elena National Cancer Institute, 00144 Rome, Italy
| | - Francesca De Nicola
- SAFU Laboratory, Department of Research, Advanced Diagnostics and Technological Innovation, Translational Research Area, IRCCS Regina Elena National Cancer Institute, 00144 Rome, Italy
| | - Stefano Scalera
- SAFU Laboratory, Department of Research, Advanced Diagnostics and Technological Innovation, Translational Research Area, IRCCS Regina Elena National Cancer Institute, 00144 Rome, Italy
| | - Gianluca Bossi
- Oncogenomic and Epigenetic Unit, Department of Research, Advanced Diagnostics and Technological Innovation, Translational Research Area, IRCCS Regina Elena National Cancer Institute, 00144 Rome, Italy
| | - Francesca Fabretti
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital of Cologne, 50937 Cologne, Germany.,CECAD, University of Cologne, Faculty of Medicine and University Hospital of Cologne, 50931 Cologne, Germany
| | - Miguel Mano
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra 3060 197, Portugal
| | - Enrico De Smaele
- Department of Experimental Medicine, Sapienza-University of Rome, 00161 Rome, Italy
| | - Maurizio Fanciulli
- SAFU Laboratory, Department of Research, Advanced Diagnostics and Technological Innovation, Translational Research Area, IRCCS Regina Elena National Cancer Institute, 00144 Rome, Italy
| | - Simona Iezzi
- SAFU Laboratory, Department of Research, Advanced Diagnostics and Technological Innovation, Translational Research Area, IRCCS Regina Elena National Cancer Institute, 00144 Rome, Italy
| |
Collapse
|
13
|
Gaviraghi M, Vivori C, Tonon G. How Cancer Exploits Ribosomal RNA Biogenesis: A Journey beyond the Boundaries of rRNA Transcription. Cells 2019; 8:cells8091098. [PMID: 31533350 PMCID: PMC6769540 DOI: 10.3390/cells8091098] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 09/13/2019] [Accepted: 09/15/2019] [Indexed: 02/06/2023] Open
Abstract
The generation of new ribosomes is a coordinated process essential to sustain cell growth. As such, it is tightly regulated according to cell needs. As cancer cells require intense protein translation to ensure their enhanced growth rate, they exploit various mechanisms to boost ribosome biogenesis. In this review, we will summarize how oncogenes and tumor suppressors modulate the biosynthesis of the RNA component of ribosomes, starting from the description of well-characterized pathways that converge on ribosomal RNA transcription while including novel insights that reveal unexpected regulatory networks hacked by cancer cells to unleash ribosome production.
Collapse
Affiliation(s)
- Marco Gaviraghi
- Experimental Imaging Center; Ospedale San Raffaele, 20132 Milan, Italy.
- Functional Genomics of Cancer Unit, Division of Experimental Oncology, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) San Raffaele Scientific Institute, 20132 Milan, Italy.
| | - Claudia Vivori
- Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, 08003 Barcelona, Spain.
| | - Giovanni Tonon
- Functional Genomics of Cancer Unit, Division of Experimental Oncology, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) San Raffaele Scientific Institute, 20132 Milan, Italy.
- Center for Translational Genomics and Bioinformatics, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) San Raffaele Scientific Institute, 20132 Milan, Italy.
| |
Collapse
|
14
|
Hodson N, West DWD, Philp A, Burd NA, Moore DR. Molecular regulation of human skeletal muscle protein synthesis in response to exercise and nutrients: a compass for overcoming age-related anabolic resistance. Am J Physiol Cell Physiol 2019; 317:C1061-C1078. [PMID: 31461340 DOI: 10.1152/ajpcell.00209.2019] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Skeletal muscle mass, a strong predictor of longevity and health in humans, is determined by the balance of two cellular processes, muscle protein synthesis (MPS) and muscle protein breakdown. MPS seems to be particularly sensitive to changes in mechanical load and/or nutritional status; therefore, much research has focused on understanding the molecular mechanisms that underpin this cellular process. Furthermore, older individuals display an attenuated MPS response to anabolic stimuli, termed anabolic resistance, which has a negative impact on muscle mass and function, as well as quality of life. Therefore, an understanding of which, if any, molecular mechanisms contribute to anabolic resistance of MPS is of vital importance in formulation of therapeutic interventions for such populations. This review summarizes the current knowledge of the mechanisms that underpin MPS, which are broadly divided into mechanistic target of rapamycin complex 1 (mTORC1)-dependent, mTORC1-independent, and ribosomal biogenesis-related, and describes the evidence that shows how they are regulated by anabolic stimuli (exercise and/or nutrition) in healthy human skeletal muscle. This review also summarizes evidence regarding which of these mechanisms may be implicated in age-related skeletal muscle anabolic resistance and provides recommendations for future avenues of research that can expand our knowledge of this area.
Collapse
Affiliation(s)
- Nathan Hodson
- Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada
| | - Daniel W D West
- Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada
| | - Andrew Philp
- Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales, Australia
| | - Nicholas A Burd
- Department of Kinesiology and Community Health, University of Illinois, Urbana, Illinois
| | - Daniel R Moore
- Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada
| |
Collapse
|
15
|
Chen J, Lobb IT, Morin P, Novo SM, Simpson J, Kennerknecht K, von Kriegsheim A, Batchelor EE, Oakley F, Stark LA. Identification of a novel TIF-IA-NF-κB nucleolar stress response pathway. Nucleic Acids Res 2019; 46:6188-6205. [PMID: 29873780 PMCID: PMC6158704 DOI: 10.1093/nar/gky455] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 05/14/2018] [Indexed: 12/13/2022] Open
Abstract
p53 as an effector of nucleolar stress is well defined, but p53 independent mechanisms are largely unknown. Like p53, the NF-κB transcription factor plays a critical role in maintaining cellular homeostasis under stress. Many stresses that stimulate NF-κB also disrupt nucleoli. However, the link between nucleolar function and activation of the NF-κB pathway is as yet unknown. Here we demonstrate that artificial disruption of the PolI complex stimulates NF-κB signalling. Unlike p53 nucleolar stress response, this effect does not appear to be linked to inhibition of rDNA transcription. We show that specific stress stimuli of NF-κB induce degradation of a critical component of the PolI complex, TIF-IA. This degradation precedes activation of NF-κB and is associated with increased nucleolar size. It is mimicked by CDK4 inhibition and is dependent upon a novel pathway involving UBF/p14ARF and S44 of the protein. We show that blocking TIF-IA degradation blocks stress effects on nucleolar size and NF-κB signalling. Finally, using ex vivo culture, we show a strong correlation between degradation of TIF-IA and activation of NF-κB in freshly resected, human colorectal tumours exposed to the chemopreventative agent, aspirin. Together, our study provides compelling evidence for a new, TIF-IA-NF-κB nucleolar stress response pathway that has in vivo relevance and therapeutic implications.
Collapse
Affiliation(s)
- Jingyu Chen
- University of Edinburgh Cancer Research Centre, Institute of Genetics and Molecular Medicine, Western General Hospital, Crewe Rd., Edinburgh EH4 2XU, UK
| | - Ian T Lobb
- University of Edinburgh Cancer Research Centre, Institute of Genetics and Molecular Medicine, Western General Hospital, Crewe Rd., Edinburgh EH4 2XU, UK
| | - Pierre Morin
- University of Edinburgh Cancer Research Centre, Institute of Genetics and Molecular Medicine, Western General Hospital, Crewe Rd., Edinburgh EH4 2XU, UK
| | - Sonia M Novo
- University of Edinburgh Cancer Research Centre, Institute of Genetics and Molecular Medicine, Western General Hospital, Crewe Rd., Edinburgh EH4 2XU, UK
| | - James Simpson
- University of Edinburgh Cancer Research Centre, Institute of Genetics and Molecular Medicine, Western General Hospital, Crewe Rd., Edinburgh EH4 2XU, UK
| | - Kathrin Kennerknecht
- University of Edinburgh Cancer Research Centre, Institute of Genetics and Molecular Medicine, Western General Hospital, Crewe Rd., Edinburgh EH4 2XU, UK
| | - Alex von Kriegsheim
- University of Edinburgh Cancer Research Centre, Institute of Genetics and Molecular Medicine, Western General Hospital, Crewe Rd., Edinburgh EH4 2XU, UK
| | - Emily E Batchelor
- University of Edinburgh Cancer Research Centre, Institute of Genetics and Molecular Medicine, Western General Hospital, Crewe Rd., Edinburgh EH4 2XU, UK
| | - Fiona Oakley
- Liver Research Group, Institute of Cellular Medicine, 4th Floor, William Leech Building, Framlington Place, Newcastle University, Newcastle Upon Tyne NE2 4HH, UK
| | - Lesley A Stark
- University of Edinburgh Cancer Research Centre, Institute of Genetics and Molecular Medicine, Western General Hospital, Crewe Rd., Edinburgh EH4 2XU, UK
| |
Collapse
|
16
|
Kotani T, Takegaki J, Takagi R, Nakazato K, Ishii N. Consecutive bouts of electrical stimulation-induced contractions alter ribosome biogenesis in rat skeletal muscle. J Appl Physiol (1985) 2019; 126:1673-1680. [DOI: 10.1152/japplphysiol.00665.2018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Ribosome biogenesis has been implicated in resistance exercise training (RET)-induced skeletal muscle hypertrophy. However, it is unclear how increasing bouts of RET affects ribosome content and biogenesis. This was investigated in the present study using simulated RET where rat skeletal muscle is subjected to increasing bouts of electrical stimulation. Sprague-Dawley rats were randomly assigned to the following seven groups: sedentary for 5 days (SED) or 6 wk (SED_6w), resistance-exercise trained with 1 bout (1B), 2 bouts (2B), 3 bouts (3B), 6 bouts (6B), and 18 bouts (18B). RET was simulated on the right gastrocnemius muscle by transcutaneous electric stimulation under isoflurane anesthesia, and a RET bout was given 3 times a week. Rats in 1B, 2B, and 3B groups showed increased 45S precursor (pre-) rRNA and 18S+28S rRNA content per muscle weight and elevated mRNA levels of c- myc and upstream binding factor (UBF). Increases in phosphorylated UBF and total cyclin D1 protein level were observed 48 h after RET; the former increased as a function of RET duration. In 3B, 6B, and 18B groups, the 18S+28S rRNA content per muscle weight was kept unchanged, and 45S pre-rRNA, cyclin D1, and phosphorylated UBF levels in 18B were lower than those in 3B. These results suggest that RET activates ribosome biogenesis and increases ribosome content through modulation of UBF and cyclin D1 activity at its early phase. Additional bouts of RET may not lead to a further increase in ribosome content per muscle weight through possibly the attenuation of transcription process. NEW & NOTEWORTHY Ribosome biogenesis has been implicated in resistance exercise training-induced skeletal muscle hypertrophy. However, it remains unclear how this is influenced by the volume of repeated bouts of resistance exercise training. Using resistance exercise training model with rat skeletal muscle, we provide evidence that ribosome biogenesis is stimulated by the initial few bouts of resistance exercise training with no additional effect of further increase in the exercise bout.
Collapse
Affiliation(s)
- Takaya Kotani
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan
| | - Junya Takegaki
- Ritsumeikan Global Innovation Research Organization, Ritsumeikan University, Shiga, Japan
| | - Ryo Takagi
- Graduate School of Health and Sport Science, Nippon Sport Science University, Tokyo, Japan
| | - Koichi Nakazato
- Graduate School of Health and Sport Science, Nippon Sport Science University, Tokyo, Japan
| | - Naokata Ishii
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan
| |
Collapse
|
17
|
Figueiredo VC, McCarthy JJ. Regulation of Ribosome Biogenesis in Skeletal Muscle Hypertrophy. Physiology (Bethesda) 2019; 34:30-42. [PMID: 30540235 PMCID: PMC6383632 DOI: 10.1152/physiol.00034.2018] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 09/11/2018] [Accepted: 09/13/2018] [Indexed: 01/22/2023] Open
Abstract
The ribosome is the enzymatic macromolecular machine responsible for protein synthesis. The rates of protein synthesis are primarily dependent on translational efficiency and capacity. Ribosome biogenesis has emerged as an important regulator of skeletal muscle growth and maintenance by altering the translational capacity of the cell. Here, we provide evidence to support a central role for ribosome biogenesis in skeletal muscle growth during postnatal development and in response to resistance exercise training. Furthermore, we discuss the cellular signaling pathways regulating ribosome biogenesis, discuss how myonuclear accretion affects translational capacity, and explore future areas of investigation within the field.
Collapse
Affiliation(s)
- Vandré Casagrande Figueiredo
- The Center for Muscle Biology, College of Health Sciences, University of Kentucky , Lexington, Kentucky
- Department of Rehabilitation Sciences, College of Medicine, University of Kentucky , Lexington, Kentucky
| | - John J McCarthy
- The Center for Muscle Biology, College of Health Sciences, University of Kentucky , Lexington, Kentucky
- Department of Physiology, University of Kentucky , Lexington, Kentucky
| |
Collapse
|
18
|
Tadesse S, Caldon EC, Tilley W, Wang S. Cyclin-Dependent Kinase 2 Inhibitors in Cancer Therapy: An Update. J Med Chem 2018; 62:4233-4251. [PMID: 30543440 DOI: 10.1021/acs.jmedchem.8b01469] [Citation(s) in RCA: 139] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Cyclin-dependent kinase 2 (CDK2) drives the progression of cells into the S- and M-phases of the cell cycle. CDK2 activity is largely dispensable for normal development, but it is critically associated with tumor growth in multiple cancer types. Although the role of CDK2 in tumorigenesis has been controversial, emerging evidence proposes that selective CDK2 inhibition may provide a therapeutic benefit against certain tumors, and it continues to appeal as a strategy to exploit in anticancer drug development. Several small-molecule CDK2 inhibitors have progressed to the clinical trials. However, a CDK2-selective inhibitor is yet to be discovered. Here, we discuss the latest understandings of the role of CDK2 in normal and cancer cells, review the core pharmacophores used to target CDK2, and outline strategies for the rational design of CDK2 inhibitors. We attempt to provide an outlook on how CDK2-selective inhibitors may open new avenues for cancer therapy.
Collapse
Affiliation(s)
- Solomon Tadesse
- Centre for Drug Discovery and Development , University of South Australia Cancer Research Institute , Adelaide , SA 5000 , Australia
| | - Elizabeth C Caldon
- The Kinghorn Cancer Centre , Garvan Institute of Medical Research , Darlinghurst , NSW 2010 , Australia.,St Vincent's Clinical School, UNSW Medicine , UNSW Sydney , Darlinghurst , NSW 2010 , Australia
| | - Wayne Tilley
- Adelaide Medical School , University of Adelaide , Adelaide , SA 5000 , Australia
| | - Shudong Wang
- Centre for Drug Discovery and Development , University of South Australia Cancer Research Institute , Adelaide , SA 5000 , Australia
| |
Collapse
|
19
|
Dynamic localization of α-tubulin acetyltransferase ATAT1 through the cell cycle in human fibroblastic KD cells. Med Mol Morphol 2018; 51:217-226. [PMID: 29869029 DOI: 10.1007/s00795-018-0195-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 06/01/2018] [Indexed: 12/22/2022]
Abstract
Acetylation of α-tubulin is a well-studied posttranscriptional modification, which is mostly catalyzed by α-tubulin N-acetyltransferase (ATAT1). ATAT1 possibly affects various cellular functions related with microtubules, such as intracellular transport, cell motility, cilia formation, and neuronal signaling. Here, we analyzed the subcellular localization of immunolabeled ATAT1 in human fibroblast KD cells through the cell cycle using confocal laser scanning microscopy. ATAT1 dramatically changed its localization through the cell cycle, depending on the mitotic phase. In interphase, immunolabeled ATAT1 was observed in centrioles, nuclei, and basal bodies if the cells projected primary cilia. ATAT1 was intensely detected as clusters in the nuclei in the G1-G2 phase. In telophase, ATAT1 colocalized with chromatids and spindle poles, and ultimately migrated to the daughter nucleus, newly synthesized centrioles, and midbody. The nucleolus is a core region of ribosomal RNA transcription, and the midbody is associated with severing and depolymerizing of microtubules in the stembody. The specific distributions of ATAT1 through the cell cycle suggest multiple functions of ATAT1, which could include acetylation of microtubules, RNA transcription activity, severing microtubules, and completion of cytokinesis.
Collapse
|
20
|
Bachs O, Gallastegui E, Orlando S, Bigas A, Morante-Redolat JM, Serratosa J, Fariñas I, Aligué R, Pujol MJ. Role of p27 Kip1 as a transcriptional regulator. Oncotarget 2018; 9:26259-26278. [PMID: 29899857 PMCID: PMC5995243 DOI: 10.18632/oncotarget.25447] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 05/01/2018] [Indexed: 12/16/2022] Open
Abstract
The protein p27Kip1 is a member of the Cip/Kip family of cyclin-dependent kinase (Cdk) inhibitors. It interacts with both the catalytic and the regulatory subunit (cyclin) and introduces a region into the catalytic cleave of the Cdk inducing its inactivation. Its inhibitory capacity can be modulated by specific tyrosine phosphorylations. p27Kip1 also behaves as a transcriptional regulator. It associates with specific chromatin domains through different transcription factors. ChIP on chip, ChIP-seq and expression microarray analysis allowed the identification of the transcriptional programs regulated by p27Kip1. Thus, important cellular functions as cell division cycle, respiration, RNA processing, translation and cell adhesion, are under p27Kip1 regulation. Moreover, genes involved in pathologies as cancer and neurodegeneration are also regulated by p27Kip1, suggesting its implication in these pathologies. The carboxyl moiety of p27Kip1 can associate with different proteins, including transcriptional regulators. In contrast, its NH2-terminal region specifically interacts with cyclin-Cdk complexes. The general mechanistic model of how p27Kip1 regulates transcription is that it associates by its COOH region to the transcriptional regulators on the chromatin and by the NH2-domain to cyclin-Cdk complexes. After Cdk activation it would phosphorylate the specific targets on the chromatin leading to gene expression. This model has been demonstrated to apply in the transcriptional regulation of p130/E2F4 repressed genes involved in cell cycle progression. We summarize in this review our current knowledge on the role of p27Kip1 in the regulation of transcription, on the transcriptional programs under its regulation and on its relevance in pathologies as cancer and neurodegeneration.
Collapse
Affiliation(s)
- Oriol Bachs
- Department of Biomedical Sciences, Faculty of Medicine, University of Barcelona, IDIBAPS, CIBERONC, Barcelona, Spain
| | - Edurne Gallastegui
- Department of Biomedical Sciences, Faculty of Medicine, University of Barcelona, IDIBAPS, CIBERONC, Barcelona, Spain
| | - Serena Orlando
- Department of Biomedical Sciences, Faculty of Medicine, University of Barcelona, IDIBAPS, CIBERONC, Barcelona, Spain
| | - Anna Bigas
- Program in Cancer Research, Institut Hospital Del Mar d'Investigacions Mèdiques (IMIM), CIBERONC, Barcelona, Spain
| | - José Manuel Morante-Redolat
- Departamento de Biología Celular, Biología Funcional y Antropología Física and ERI de Biotecnología y Biomedicina, CIBERNED, Universidad de Valencia, Valencia, Spain
| | - Joan Serratosa
- Department of Cerebral Ischemia and Neurodegeneration, Institut d'Investigacions Biomèdiques de Barcelona, Consejo Superior de Investigaciones Científicas (CSIC), IDIBAPS, Barcelona, Spain
| | - Isabel Fariñas
- Departamento de Biología Celular, Biología Funcional y Antropología Física and ERI de Biotecnología y Biomedicina, CIBERNED, Universidad de Valencia, Valencia, Spain
| | - Rosa Aligué
- Department of Biomedical Sciences, Faculty of Medicine, University of Barcelona, IDIBAPS, CIBERONC, Barcelona, Spain
| | - Maria Jesús Pujol
- Department of Biomedical Sciences, Faculty of Medicine, University of Barcelona, IDIBAPS, CIBERONC, Barcelona, Spain
| |
Collapse
|
21
|
Chen H, Duo Y, Hu B, Wang Z, Zhang F, Tsai H, Zhang J, Zhou L, Wang L, Wang X, Huang L. PICT-1 triggers a pro-death autophagy through inhibiting rRNA transcription and AKT/mTOR/p70S6K signaling pathway. Oncotarget 2018; 7:78747-78763. [PMID: 27729611 PMCID: PMC5346674 DOI: 10.18632/oncotarget.12288] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 09/16/2016] [Indexed: 01/05/2023] Open
Abstract
PICT-1 was originally identified as a tumor suppressor. Here, we found that PICT-1 overexpression triggered pro-death autophagy without nucleolar disruption or p53 accumulation in U251 and MCF7 cells. Truncated PICT-1 fragments 181-346 and 1-346, which partly or totally lack nucleolar localization, showed weaker autophagy-inducing effects than full-length PICT-1 and a well-defined nucleolar mutant (181-479). Furthermore, PICT-1 partly localizes to the nucleolar fibrillar center (FC) and directly binds to ribosomal DNA (rDNA) gene loci, where it interacts with upstream binding factor (UBF). Overexpression of PICT-1 or the 181-479 mutant, but not the 1-346 or 181-346 mutants, markedly inhibited the phosphorylation of UBF and the recruitment of rRNA polymerase I (Pol I) to the rDNA promoter in response to serum stimulation, thereby suppressing rRNA transcription, suggesting that rRNA transcription inhibition might be an important contributor to PICT-1-induced autophagy. This is supported by the finding that CX-5461, a specific Pol I inhibitor, also induced autophagy. In addition, both CX-5461 and PICT-1, but not the 1-346 or 181-346 mutants, significantly suppressed the activation of the Akt/mTOR/p70S6K signaling pathway. Our data show that PICT-1 triggers pro-death autophagy through inhibition of rRNA transcription and the inactivation of AKT/mTOR/p70S6K pathway, independent of nucleolar disruption and p53 activation.
Collapse
Affiliation(s)
- Hongbo Chen
- The Shenzhen Key Lab of Gene and Antibody Therapy, Center for Biotechnology & Biomedicine, Division of Life and Health Sciences, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China.,School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Yanhong Duo
- Key Laboratory of Plant Cell Activities and Stress Adaptation, Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - Bo Hu
- Department of Laboratory Medicine, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou 510630, China
| | - Zhiwei Wang
- Department of Laboratory Medicine, The Fourth Affiliated Hospital of Guangzhou Medical University, Guangzhou 511447, China
| | - Fang Zhang
- The Shenzhen Key Laboratory of Gene and Antibody Therapy, Center for Biotechnology & Biomedicine, Division of Life and Health Sciences, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China
| | - Hsiangi Tsai
- The Shenzhen Key Laboratory of Gene and Antibody Therapy, Center for Biotechnology & Biomedicine, Division of Life and Health Sciences, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China.,School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Jianping Zhang
- Department of Quality Inspection, Shenzhen Weiguang Biological Products Co., Ltd, Shenzhen 518107, China
| | - Lanzhen Zhou
- Department of Quality Inspection, Shenzhen Weiguang Biological Products Co., Ltd, Shenzhen 518107, China
| | - Lijun Wang
- The Shenzhen Key Laboratory of Gene and Antibody Therapy, Center for Biotechnology & Biomedicine, Division of Life and Health Sciences, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China
| | - Xinyu Wang
- Key Laboratory of Plant Cell Activities and Stress Adaptation, Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - Laiqiang Huang
- The Shenzhen Key Laboratory of Gene and Antibody Therapy, Center for Biotechnology & Biomedicine, Division of Life and Health Sciences, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China.,School of Life Sciences, Tsinghua University, Beijing 100084, China
| |
Collapse
|
22
|
Toro C, Hori RT, Malicdan MCV, Tifft CJ, Goldstein A, Gahl WA, Adams DR, Fauni HB, Wolfe LA, Xiao J, Khan MM, Tian J, Hope KA, Reiter LT, Tremblay MG, Moss T, Franks AL, Balak C, LeDoux MS. A recurrent de novo missense mutation in UBTF causes developmental neuroregression. Hum Mol Genet 2018; 27:691-705. [PMID: 29300972 PMCID: PMC5886272 DOI: 10.1093/hmg/ddx435] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 11/29/2017] [Accepted: 12/19/2017] [Indexed: 12/17/2022] Open
Abstract
UBTF (upstream binding transcription factor) exists as two isoforms; UBTF1 regulates rRNA transcription by RNA polymerase 1, whereas UBTF2 regulates mRNA transcription by RNA polymerase 2. Herein, we describe 4 patients with very similar patterns of neuroregression due to recurrent de novo mutations in UBTF (GRCh37/hg19, NC_000017.10: g.42290219C > T, NM_014233.3: c.628G > A) resulting in the same amino acid change in both UBTF1 and UBTF2 (p.Glu210Lys [p.E210K]). Disease onset in our cohort was at 2.5 to 3 years and characterized by slow progression of global motor, cognitive and behavioral dysfunction. Notable early features included hypotonia with a floppy gait, high-pitched dysarthria and hyperactivity. Later features included aphasia, dystonia, and spasticity. Speech and ambulatory ability were lost by the early teens. Magnetic resonance imaging showed progressive generalized cerebral atrophy (supratentorial > infratentorial) with involvement of both gray and white matter. Patient fibroblasts showed normal levels of UBTF transcripts, increased expression of pre-rRNA and 18S rRNA, nucleolar abnormalities, markedly increased numbers of DNA breaks, defective cell-cycle progression, and apoptosis. Expression of mutant human UBTF1 in Drosophila neurons was lethal. Although no loss-of-function variants are reported in the Exome Aggregation Consortium (ExAC) database and Ubtf-/- is early embryonic lethal in mice, Ubtf+/- mice displayed only mild motor and behavioral dysfunction in adulthood. Our data underscore the importance of including UBTF E210K in the differential diagnosis of neuroregression and suggest that mainly gain-of-function mechanisms contribute to the pathogenesis of the UBTF E210K neuroregression syndrome.
Collapse
Affiliation(s)
- Camilo Toro
- Undiagnosed Diseases Program and Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Roderick T Hori
- Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center, Memphis, TN, USA
| | - May Christine V Malicdan
- Undiagnosed Diseases Program and Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Cynthia J Tifft
- Undiagnosed Diseases Program and Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Amy Goldstein
- Division of Child Neurology, Department of Pediatrics, Children’s Hospital of Pittsburgh, Pittsburgh, PA, USA
| | - William A Gahl
- Undiagnosed Diseases Program and Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - David R Adams
- Undiagnosed Diseases Program and Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Harper B Fauni
- Undiagnosed Diseases Program and Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Lynne A Wolfe
- Undiagnosed Diseases Program and Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Jianfeng Xiao
- Departments of Neurology and Anatomy & Neurobiology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Mohammad M Khan
- Departments of Neurology and Anatomy & Neurobiology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Jun Tian
- Departments of Neurology and Anatomy & Neurobiology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Kevin A Hope
- Integrated Program in Biological Sciences, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Lawrence T Reiter
- Departments of Neurology and Anatomy & Neurobiology, University of Tennessee Health Science Center, Memphis, TN, USA
- Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Michel G Tremblay
- Laboratory of Growth and Development, St-Patrick Research Group in Basic Oncology, Cancer Division of the Quebec University Hospital Research Centre, Canada
- Department of Molecular Biology, Medical Biochemistry and Pathology, Faculty of Medicine, Laval University, QC, Canada
| | - Tom Moss
- Laboratory of Growth and Development, St-Patrick Research Group in Basic Oncology, Cancer Division of the Quebec University Hospital Research Centre, Canada
- Department of Molecular Biology, Medical Biochemistry and Pathology, Faculty of Medicine, Laval University, QC, Canada
| | - Alexis L Franks
- Division of Child Neurology, Department of Pediatrics, Children’s Hospital of Pittsburgh, Pittsburgh, PA, USA
| | - Chris Balak
- Center for Rare Childhood Disorders (C4RCD), Translational Genomics Research Institute (TGen), Phoenix, AZ, USA
| | - C4RCD Research Group
- Center for Rare Childhood Disorders (C4RCD), Translational Genomics Research Institute (TGen), Phoenix, AZ, USA
| | - Mark S LeDoux
- Departments of Neurology and Anatomy & Neurobiology, University of Tennessee Health Science Center, Memphis, TN, USA
| |
Collapse
|
23
|
Enhanced skeletal muscle ribosome biogenesis, yet attenuated mTORC1 and ribosome biogenesis-related signalling, following short-term concurrent versus single-mode resistance training. Sci Rep 2018; 8:560. [PMID: 29330460 PMCID: PMC5766515 DOI: 10.1038/s41598-017-18887-6] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 12/08/2017] [Indexed: 01/31/2023] Open
Abstract
Combining endurance training with resistance training (RT) may attenuate skeletal muscle hypertrophic adaptation versus RT alone; however, the underlying mechanisms are unclear. We investigated changes in markers of ribosome biogenesis, a process linked with skeletal muscle hypertrophy, following concurrent training versus RT alone. Twenty-three males underwent eight weeks of RT, either performed alone (RT group, n = 8), or combined with either high-intensity interval training (HIT+RT group, n = 8), or moderate-intensity continuous training (MICT+RT group, n = 7). Muscle samples (vastus lateralis) were obtained before training, and immediately before, 1 h and 3 h after the final training session. Training-induced changes in basal expression of the 45S ribosomal RNA (rRNA) precursor (45S pre-rRNA), and 5.8S and 28S mature rRNAs, were greater with concurrent training versus RT. However, during the final training session, RT further increased both mTORC1 (p70S6K1 and rps6 phosphorylation) and 45S pre-rRNA transcription-related signalling (TIF-1A and UBF phosphorylation) versus concurrent training. These data suggest that when performed in a training-accustomed state, RT induces further increases mTORC1 and ribosome biogenesis-related signalling in human skeletal muscle versus concurrent training; however, changes in ribosome biogenesis markers were more favourable following a period of short-term concurrent training versus RT performed alone.
Collapse
|
24
|
Cai S, Liu X, Zhang C, Xing B, Du X. Autoacetylation of NAT10 is critical for its function in rRNA transcription activation. Biochem Biophys Res Commun 2016; 483:624-629. [PMID: 27993683 DOI: 10.1016/j.bbrc.2016.12.092] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 12/13/2016] [Indexed: 01/13/2023]
Abstract
NAT10, an important member of GNAT family, harbors histone acetyltransferase and participates in many cellular processes such as ribosome production and cell cycle. Here, we report that NAT10 is acetylated in vivo and autoacetylated in vitro. The lysine residue at 426 (K426) is the acetylation site of NAT10. K426R mutant of NAT10 fails to activate rRNA transcription. NAT10 K426R loses its capability of acetylating UBF though it still binds UBF, which fails to recruit PAF53 and RNA polymerase I to rDNA, eventually resulting in inhibition of pre-rRNA transcription. Therefore, acetylation of K426 in NAT10 is required for its function in activating rRNA transcription. These findings identify a new post-translational modification on NAT10 which regulates its function.
Collapse
Affiliation(s)
- Shiying Cai
- Department of Cell Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Xiaofeng Liu
- Department of Cell Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Chunfeng Zhang
- Department of Medical Genetics, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Baocai Xing
- Hepatopancreatobiliary Surgery Department I, Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Peking University School of Oncology, Beijing Cancer Hospital and Institute, No. 52, Fu-Cheng Road, Beijing 100142, China
| | - Xiaojuan Du
- Department of Cell Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China.
| |
Collapse
|
25
|
Abstract
Eukaryotic genomes are packaged in chromatin. The higher-order organization of nucleosome core particles is controlled by the association of the intervening linker DNA with either the linker histone H1 or high mobility group box (HMGB) proteins. While H1 is thought to stabilize the nucleosome by preventing DNA unwrapping, the DNA bending imposed by HMGB may propagate to the nucleosome to destabilize chromatin. For metazoan H1, chromatin compaction requires its lysine-rich C-terminal domain, a domain that is buried between globular domains in the previously characterized yeast Saccharomyces cerevisiae linker histone Hho1p. Here, we discuss the functions of S. cerevisiae HMO1, an HMGB family protein unique in containing a terminal lysine-rich domain and in stabilizing genomic DNA. On ribosomal DNA (rDNA) and genes encoding ribosomal proteins, HMO1 appears to exert its role primarily by stabilizing nucleosome-free regions or "fragile" nucleosomes. During replication, HMO1 likewise appears to ensure low nucleosome density at DNA junctions associated with the DNA damage response or the need for topoisomerases to resolve catenanes. Notably, HMO1 shares with the mammalian linker histone H1 the ability to stabilize chromatin, as evidenced by the absence of HMO1 creating a more dynamic chromatin environment that is more sensitive to nuclease digestion and in which chromatin-remodeling events associated with DNA double-strand break repair occur faster; such chromatin stabilization requires the lysine-rich extension of HMO1. Thus, HMO1 appears to have evolved a unique linker histone-like function involving the ability to stabilize both conventional nucleosome arrays as well as DNA regions characterized by low nucleosome density or the presence of noncanonical nucleosomes.
Collapse
|
26
|
Juli G, Gismondi A, Monteleone V, Caldarola S, Iadevaia V, Aspesi A, Dianzani I, Proud CG, Loreni F. Depletion of ribosomal protein S19 causes a reduction of rRNA synthesis. Sci Rep 2016; 6:35026. [PMID: 27734913 PMCID: PMC5062126 DOI: 10.1038/srep35026] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 09/19/2016] [Indexed: 12/25/2022] Open
Abstract
Ribosome biogenesis plays key roles in cell growth by providing increased capacity for protein synthesis. It requires coordinated production of ribosomal proteins (RP) and ribosomal RNA (rRNA), including the processing of the latter. Here, we show that, the depletion of RPS19 causes a reduction of rRNA synthesis in cell lines of both erythroid and non-erythroid origin. A similar effect is observed upon depletion of RPS6 or RPL11. The deficiency of RPS19 does not alter the stability of rRNA, but instead leads to an inhibition of RNA Polymerase I (Pol I) activity. In fact, results of nuclear run-on assays and ChIP experiments show that association of Pol I with the rRNA gene is reduced in RPS19-depleted cells. The phosphorylation of three known regulators of Pol I, CDK2, AKT and AMPK, is altered during ribosomal stress and could be involved in the observed downregulation. Finally, RNA from patients with Diamond Blackfan Anemia (DBA), shows, on average, a lower level of 47S precursor. This indicates that inhibition of rRNA synthesis could be one of the molecular alterations at the basis of DBA.
Collapse
Affiliation(s)
- Giada Juli
- Department of Biology, University of Rome Tor Vergata, Roma, Italy
| | - Angelo Gismondi
- Department of Biology, University of Rome Tor Vergata, Roma, Italy
| | | | - Sara Caldarola
- Department of Biology, University of Rome Tor Vergata, Roma, Italy
| | - Valentina Iadevaia
- Centre for Biological Sciences, University of Southampton, Southampton, UK
| | - Anna Aspesi
- Department of Health Sciences, Università del Piemonte Orientale, Novara, Italy
| | - Irma Dianzani
- Department of Health Sciences, Università del Piemonte Orientale, Novara, Italy
| | | | - Fabrizio Loreni
- Department of Biology, University of Rome Tor Vergata, Roma, Italy
| |
Collapse
|
27
|
Figueiredo VC, Roberts LA, Markworth JF, Barnett MPG, Coombes JS, Raastad T, Peake JM, Cameron-Smith D. Impact of resistance exercise on ribosome biogenesis is acutely regulated by post-exercise recovery strategies. Physiol Rep 2016; 4:4/2/e12670. [PMID: 26818586 PMCID: PMC4760384 DOI: 10.14814/phy2.12670] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Muscle hypertrophy occurs following increased protein synthesis, which requires activation of the ribosomal complex. Additionally, increased translational capacity via elevated ribosomal RNA (rRNA) synthesis has also been implicated in resistance training-induced skeletal muscle hypertrophy. The time course of ribosome biogenesis following resistance exercise (RE) and the impact exerted by differing recovery strategies remains unknown. In the present study, the activation of transcriptional regulators, the expression levels of pre-rRNA, and mature rRNA components were measured through 48 h after a single-bout RE. In addition, the effects of either low-intensity cycling (active recovery, ACT) or a cold-water immersion (CWI) recovery strategy were compared. Nine male subjects performed two bouts of high-load RE randomized to be followed by 10 min of either ACT or CWI. Muscle biopsies were collected before RE and at 2, 24, and 48 h after RE. RE increased the phosphorylation of the p38-MNK1-eIF4E axis, an effect only evident with ACT recovery. Downstream, cyclin D1 protein, total eIF4E, upstream binding factor 1 (UBF1), and c-Myc proteins were all increased only after RE with ACT. This corresponded with elevated abundance of the pre-rRNAs (45S, ITS-28S, ITS-5.8S, and ETS-18S) from 24 h after RE with ACT. In conclusion, coordinated upstream signaling and activation of transcriptional factors stimulated pre-rRNA expression after RE. CWI, as a recovery strategy, markedly blunted these events, suggesting that suppressed ribosome biogenesis may be one factor contributing to the impaired hypertrophic response observed when CWI is used regularly after exercise.
Collapse
Affiliation(s)
| | - Llion A Roberts
- School of Human Movement and Nutrition Sciences The University of Queensland, Brisbane, Australia Centre of Excellence for Applied Sport Science Research, Queensland Academy of Sport, Brisbane, Australia
| | - James F Markworth
- The Liggins Institute, The University of Auckland, Auckland, New Zealand
| | - Matthew P G Barnett
- AgResearch Limited, Grasslands Research Centre, Palmerston North, New Zealand
| | - Jeff S Coombes
- School of Human Movement and Nutrition Sciences The University of Queensland, Brisbane, Australia
| | | | - Jonathan M Peake
- Centre of Excellence for Applied Sport Science Research, Queensland Academy of Sport, Brisbane, Australia School of Biomedical Sciences and Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia
| | | |
Collapse
|
28
|
Huang S, Xu X, Wang G, Lu G, Xie W, Tao W, Zhang H, Jiang Q, Zhang C. DNA replication initiator Cdc6 also regulates ribosomal DNA transcription initiation. J Cell Sci 2016; 129:1429-40. [PMID: 26872786 DOI: 10.1242/jcs.178723] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 02/06/2016] [Indexed: 01/28/2023] Open
Abstract
RNA-polymerase-I-dependent ribosomal DNA (rDNA) transcription is fundamental to rRNA processing, ribosome assembly and protein synthesis. However, how this process is initiated during the cell cycle is not fully understood. By performing a proteomic analysis of transcription factors that bind RNA polymerase I during rDNA transcription initiation, we identified that the DNA replication initiator Cdc6 interacts with RNA polymerase I and its co-factors, and promotes rDNA transcription in G1 phase in an ATPase-activity-dependent manner. We further showed that Cdc6 is targeted to the nucleolus during late mitosis and G1 phase in a manner that is dependent on B23 (also known as nucleophosmin, NPM1), and preferentially binds to the rDNA promoter through its ATP-binding domain. Overexpression of Cdc6 increases rDNA transcription, whereas knockdown of Cdc6 results in a decreased association of both RNA polymerase I and the RNA polymerase I transcription factor RRN3 with rDNA, and a reduction of rDNA transcription. Furthermore, depletion of Cdc6 impairs the interaction between RRN3 and RNA polymerase I. Taken together, our data demonstrate that Cdc6 also serves as a regulator of rDNA transcription initiation, and indicate a mechanism by which initiation of rDNA transcription and DNA replication can be coordinated in cells.
Collapse
Affiliation(s)
- Shijiao Huang
- The MOE Key Laboratory of Cell Proliferation and Differentiation and the State Key Laboratory of Membrane Biology, College of Life Sciences, Peking University, Beijing 100871, China
| | - Xiaowei Xu
- The MOE Key Laboratory of Cell Proliferation and Differentiation and the State Key Laboratory of Membrane Biology, College of Life Sciences, Peking University, Beijing 100871, China
| | - Guopeng Wang
- The MOE Key Laboratory of Cell Proliferation and Differentiation and the State Key Laboratory of Membrane Biology, College of Life Sciences, Peking University, Beijing 100871, China
| | - Guoliang Lu
- The MOE Key Laboratory of Cell Proliferation and Differentiation and the State Key Laboratory of Membrane Biology, College of Life Sciences, Peking University, Beijing 100871, China
| | - Wenbing Xie
- The MOE Key Laboratory of Cell Proliferation and Differentiation and the State Key Laboratory of Membrane Biology, College of Life Sciences, Peking University, Beijing 100871, China
| | - Wei Tao
- The MOE Key Laboratory of Cell Proliferation and Differentiation and the State Key Laboratory of Membrane Biology, College of Life Sciences, Peking University, Beijing 100871, China
| | - Hongyin Zhang
- Cancer Research Center, Peking University Hospital, Peking University, Beijing 100871, China
| | - Qing Jiang
- The MOE Key Laboratory of Cell Proliferation and Differentiation and the State Key Laboratory of Membrane Biology, College of Life Sciences, Peking University, Beijing 100871, China
| | - Chuanmao Zhang
- The MOE Key Laboratory of Cell Proliferation and Differentiation and the State Key Laboratory of Membrane Biology, College of Life Sciences, Peking University, Beijing 100871, China
| |
Collapse
|
29
|
West DWD, Baehr LM, Marcotte GR, Chason CM, Tolento L, Gomes AV, Bodine SC, Baar K. Acute resistance exercise activates rapamycin-sensitive and -insensitive mechanisms that control translational activity and capacity in skeletal muscle. J Physiol 2015; 594:453-68. [PMID: 26548696 DOI: 10.1113/jp271365] [Citation(s) in RCA: 110] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 10/29/2015] [Indexed: 12/19/2022] Open
Abstract
KEY POINTS Ribosome biogenesis is the primary determinant of translational capacity, but its regulation in skeletal muscle following acute resistance exercise is poorly understood. Resistance exercise increases muscle protein synthesis acutely, and muscle mass with training, but the role of translational capacity in these processes is unclear. Here, we show that acute resistance exercise activated pathways controlling translational activity and capacity through both rapamycin-sensitive and -insensitive mechanisms. Transcription factor c-Myc and its downstream targets, which are known to regulate ribosome biogenesis in other cell types, were upregulated after resistance exercise in a rapamycin-independent manner and may play a role in determining translational capacity in skeletal muscle. Local inhibition of myostatin was also not affected by rapamycin and may contribute to the rapamycin-independent effects of resistance exercise. ABSTRACT This study aimed to determine (1) the effect of acute resistance exercise on mechanisms of ribosome biogenesis, and (2) the impact of mammalian target of rapamycin on ribosome biogenesis, and muscle protein synthesis (MPS) and degradation. Female F344BN rats underwent unilateral electrical stimulation of the sciatic nerve to mimic resistance exercise in the tibialis anterior (TA) muscle. TA muscles were collected at intervals over the 36 h of exercise recovery (REx); separate groups of animals were administered rapamycin pre-exercise (REx+Rapamycin). Resistance exercise led to a prolonged (6-36 h) elevation (30-50%) of MPS that was fully blocked by rapamycin at 6 h but only partially at 18 h. REx also altered pathways that regulate protein homeostasis and mRNA translation in a manner that was both rapamycin-sensitive (proteasome activity; phosphorylation of S6K1 and rpS6) and rapamycin-insensitive (phosphorylation of eEF2, ERK1/2 and UBF; gene expression of the myostatin target Mighty as well as c-Myc and its targets involved in ribosome biogenesis). The role of c-Myc was tested in vitro using the inhibitor 10058-F4, which, over time, decreased basal RNA and MPS in a dose-dependent manner (correlation of RNA and MPS, r(2) = 0.98), even though it had no effect on the acute stimulation of protein synthesis. In conclusion, acute resistance exercise stimulated rapamycin-sensitive and -insensitive mechanisms that regulate translation activity and capacity.
Collapse
Affiliation(s)
- Daniel W D West
- Department of Physiology & Membrane Biology, University of California Davis, Davis, CA, USA
| | - Leslie M Baehr
- Department of Physiology & Membrane Biology, University of California Davis, Davis, CA, USA
| | - George R Marcotte
- Department of Physiology & Membrane Biology, University of California Davis, Davis, CA, USA
| | - Courtney M Chason
- Department of Neurobiology, Physiology & Behavior, University of California Davis, Davis, CA, USA
| | - Luis Tolento
- Department of Neurobiology, Physiology & Behavior, University of California Davis, Davis, CA, USA
| | - Aldrin V Gomes
- Department of Physiology & Membrane Biology, University of California Davis, Davis, CA, USA.,Department of Neurobiology, Physiology & Behavior, University of California Davis, Davis, CA, USA
| | - Sue C Bodine
- Department of Physiology & Membrane Biology, University of California Davis, Davis, CA, USA.,Department of Neurobiology, Physiology & Behavior, University of California Davis, Davis, CA, USA.,VA Northern California Health Care System, Mather, CA, USA
| | - Keith Baar
- Department of Physiology & Membrane Biology, University of California Davis, Davis, CA, USA.,Department of Neurobiology, Physiology & Behavior, University of California Davis, Davis, CA, USA.,VA Northern California Health Care System, Mather, CA, USA
| |
Collapse
|
30
|
Figueiredo VC, Caldow MK, Massie V, Markworth JF, Cameron-Smith D, Blazevich AJ. Ribosome biogenesis adaptation in resistance training-induced human skeletal muscle hypertrophy. Am J Physiol Endocrinol Metab 2015; 309:E72-83. [PMID: 25968575 DOI: 10.1152/ajpendo.00050.2015] [Citation(s) in RCA: 91] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 05/08/2015] [Indexed: 12/22/2022]
Abstract
Resistance training (RT) has the capacity to increase skeletal muscle mass, which is due in part to transient increases in the rate of muscle protein synthesis during postexercise recovery. The role of ribosome biogenesis in supporting the increased muscle protein synthetic demands is not known. This study examined the effect of both a single acute bout of resistance exercise (RE) and a chronic RT program on the muscle ribosome biogenesis response. Fourteen healthy young men performed a single bout of RE both before and after 8 wk of chronic RT. Muscle cross-sectional area was increased by 6 ± 4.5% in response to 8 wk of RT. Acute RE-induced activation of the ERK and mTOR pathways were similar before and after RT, as assessed by phosphorylation of ERK, MNK1, p70S6K, and S6 ribosomal protein 1 h postexercise. Phosphorylation of TIF-IA was also similarly elevated following both RE sessions. Cyclin D1 protein levels, which appeared to be regulated at the translational rather than transcriptional level, were acutely increased after RE. UBF was the only protein found to be highly phosphorylated at rest after 8 wk of training. Also, muscle levels of the rRNAs, including the precursor 45S and the mature transcripts (28S, 18S, and 5.8S), were increased in response to RT. We propose that ribosome biogenesis is an important yet overlooked event in RE-induced muscle hypertrophy that warrants further investigation.
Collapse
Affiliation(s)
| | - Marissa K Caldow
- Department of Physiology, University of Melbourne, Melbourne, Victoria, Australia; and
| | - Vivien Massie
- Centre for Exercise and Sports Science Research, School of Exercise and Health Sciences, Edith Cowan University, Joondalup, Western Australia, Australia
| | | | | | - Anthony J Blazevich
- Centre for Exercise and Sports Science Research, School of Exercise and Health Sciences, Edith Cowan University, Joondalup, Western Australia, Australia
| |
Collapse
|
31
|
Sun X, Chen H, Deng Z, Hu B, Luo H, Zeng X, Han L, Cai G, Ma L. The Warsaw breakage syndrome-related protein DDX11 is required for ribosomal RNA synthesis and embryonic development. Hum Mol Genet 2015; 24:4901-15. [PMID: 26089203 DOI: 10.1093/hmg/ddv213] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 06/04/2015] [Indexed: 12/20/2022] Open
Abstract
DDX11 was recently identified as a cause of Warsaw breakage syndrome (WABS). However, the functional mechanism of DDX11 and the contribution of clinically described mutations to the pathogenesis of WABS are elusive. Here, we show that DDX11 is a novel nucleolar protein that preferentially binds to hypomethylated active ribosomal DNA (rDNA) gene loci, where it interacts with upstream binding factor (UBF) and the RNA polymerase I (Pol I). DDX11 knockdown changed the epigenetic state of rDNA loci from euchromatic structures to more heterochromatic structures, reduced the activity of UBF, decreased the recruitment of UBF and RPA194 (a subunit of Pol I) to rDNA promoter, suppressed rRNA transcription and thereby inhibited growth and proliferation of HeLa cells. Importantly, two indentified WABS-derived mutants, R263Q and K897del, and a Fe-S deletion construct demonstrated significantly reduced binding abilities to rDNA promoters and lowered DNA-dependent ATPase activities compared with wild-type DDX11. Knockdown of the zebrafish ortholog of human DDX11 by morpholinos resulted in growth retardation and vertebral and craniofacial malformations in zebrafish, concomitant with the changes in histone epigenetic modifications at rDNA loci, the reduction of Pol I recruitment to the rDNA promoter and a significant decrease in nascent pre-RNA levels. These growth disruptions in zebrafish in response to DDX11 reduction showed similarities to the clinically described developmental abnormalities found in WABS patients for the first time in any vertebrate. Thus, our results indicate that DDX11 functions as a positive regulator of rRNA transcription and provides a novel insight into the pathogenesis of WABS.
Collapse
Affiliation(s)
- Xinliang Sun
- School of Life Sciences, Tsinghua University, Beijing, China, Division of Life Science and Health, Graduate School at Shenzhen, Tsinghua University, Shenzhen, China
| | - Hongbo Chen
- School of Life Sciences, Tsinghua University, Beijing, China, Division of Life Science and Health, Graduate School at Shenzhen, Tsinghua University, Shenzhen, China,
| | - Zaian Deng
- School of Life Sciences, Tsinghua University, Beijing, China, Division of Life Science and Health, Graduate School at Shenzhen, Tsinghua University, Shenzhen, China
| | - Bo Hu
- Department of Laboratory Medicine, The Third Affiliated Hospital of Sun Yat-sen University, Guangdong, China
| | - Hui Luo
- Department of Pharmacology, Guangdong Medical College, Zhanjiang 524023, Guangdong, China and and
| | - Xiaobin Zeng
- Department of Pharmacology, Guangdong Medical College, Zhanjiang 524023, Guangdong, China and and
| | - Liqiao Han
- Department of Laboratory Science, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangdong, China
| | - Guoping Cai
- School of Life Sciences, Tsinghua University, Beijing, China, Division of Life Science and Health, Graduate School at Shenzhen, Tsinghua University, Shenzhen, China,
| | - Lan Ma
- School of Life Sciences, Tsinghua University, Beijing, China, Division of Life Science and Health, Graduate School at Shenzhen, Tsinghua University, Shenzhen, China,
| |
Collapse
|
32
|
Harrison SJ, George A, Hannan R. A new window on cancer therapy? Targeting the nucleolus and ribosome biogenesis using the small molecule inhibitor of polymerase I transcription, CX-5461. Int J Hematol Oncol 2015. [DOI: 10.2217/ijh.15.9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Affiliation(s)
- Simon J Harrison
- Department of Haematology, Peter MacCallum Cancer Centre, East Melbourne, Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, Australia
| | - Amee George
- Department of Cancer Biology & Therapeutics, John Curtin School of Medical Research, ANU College of Medicine, Biology & The Environment, Canberra, Australia
- Department of Pathology, The University of Melbourne, Parkville, Australia
- School of Biomedical Sciences, University of Queensland, St Lucia, Australia
| | - Ross Hannan
- Department of Cancer Biology & Therapeutics, John Curtin School of Medical Research, ANU College of Medicine, Biology & The Environment, Canberra, Australia
- Research Division, Peter MacCallum Cancer Centre, East Melbourne, Australia
| |
Collapse
|
33
|
Nguyen LXT, Raval A, Garcia JS, Mitchell BS. Regulation of Ribosomal Gene Expression in Cancer. J Cell Physiol 2015; 230:1181-8. [DOI: 10.1002/jcp.24854] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Accepted: 10/16/2014] [Indexed: 12/20/2022]
Affiliation(s)
- Le Xuan Truong Nguyen
- Departments of Medicine and Chemical and Systems Biology; Stanford Cancer Institute; Stanford University School of Medicine; Stanford California
| | - Aparna Raval
- Departments of Medicine and Chemical and Systems Biology; Stanford Cancer Institute; Stanford University School of Medicine; Stanford California
| | - Jacqueline S. Garcia
- Departments of Medicine and Chemical and Systems Biology; Stanford Cancer Institute; Stanford University School of Medicine; Stanford California
| | - Beverly S. Mitchell
- Departments of Medicine and Chemical and Systems Biology; Stanford Cancer Institute; Stanford University School of Medicine; Stanford California
| |
Collapse
|
34
|
Fission yeast Cdk7 controls gene expression through both its CAK and C-terminal domain kinase activities. Mol Cell Biol 2015; 35:1480-90. [PMID: 25691663 DOI: 10.1128/mcb.00024-15] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 02/03/2015] [Indexed: 11/20/2022] Open
Abstract
Cyclin-dependent kinase (Cdk) activation and RNA polymerase II transcription are linked by the Cdk7 kinase, which phosphorylates Cdks as a trimeric Cdk-activating kinase (CAK) complex, and serine 5 within the polymerase II (Pol II) C-terminal domain (CTD) as transcription factor TFIIH-bound CAK. However, the physiological importance of integrating these processes is not understood. Besides the Cdk7 ortholog Mcs6, fission yeast possesses a second CAK, Csk1. The two enzymes have been proposed to act redundantly to activate Cdc2. Using an improved analogue-sensitive Mcs6-as kinase, we show that Csk1 is not a relevant CAK for Cdc2. Further analyses revealed that Csk1 lacks a 20-amino-acid sequence required for its budding yeast counterpart, Cak1, to bind Cdc2. Transcriptome profiling of the Mcs6-as mutant in the presence or absence of the budding yeast Cak1 kinase, in order to uncouple the CTD kinase and CAK activities of Mcs6, revealed an unanticipated role of the CAK branch in the transcriptional control of the cluster of genes implicated in ribosome biogenesis and cell growth. The analysis of a Cdc2 CAK site mutant confirmed these data. Our data show that the Cdk7 kinase modulates transcription through its well-described RNA Pol II CTD kinase activity and also through the Cdc2-activating kinase activity.
Collapse
|
35
|
Sobol M, Yildirim S, Philimonenko VV, Marášek P, Castaño E, Hozák P. UBF complexes with phosphatidylinositol 4,5-bisphosphate in nucleolar organizer regions regardless of ongoing RNA polymerase I activity. Nucleus 2014; 4:478-86. [PMID: 24513678 PMCID: PMC3925692 DOI: 10.4161/nucl.27154] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
To maintain growth and division, cells require a large-scale production of rRNAs which occurs in the nucleolus. Recently, we have shown the interaction of nucleolar phosphatidylinositol 4,5-bisphosphate (PIP2) with proteins involved in rRNA transcription and processing, namely RNA polymerase I (Pol I), UBF, and fibrillarin. Here we extend the study by investigating transcription-related localization of PIP2 in regards to transcription and processing complexes of Pol I. To achieve this, we used either physiological inhibition of transcription during mitosis or inhibition by treatment the cells with actinomycin D (AMD) or 5,6-dichloro-1β-d-ribofuranosyl-benzimidazole (DRB). We show that PIP2 is associated with Pol I subunits and UBF in a transcription-independent manner. On the other hand, PIP2/fibrillarin colocalization is dependent on the production of rRNA. These results indicate that PIP2 is required not only during rRNA production and biogenesis, as we have shown before, but also plays a structural role as an anchor for the Pol I pre-initiation complex during the cell cycle. We suggest that throughout mitosis, PIP2 together with UBF is involved in forming and maintaining the core platform of the rDNA helix structure. Thus we introduce PIP2 as a novel component of the NOR complex, which is further engaged in the renewed rRNA synthesis upon exit from mitosis.
Collapse
Affiliation(s)
- Margarita Sobol
- Institute of Molecular Genetics ASCR v.v.i.; Department of Biology of the Cell Nucleus; Prague, Czech Republic
| | - Sukriye Yildirim
- Institute of Molecular Genetics ASCR v.v.i.; Department of Biology of the Cell Nucleus; Prague, Czech Republic
| | - Vlada V Philimonenko
- Institute of Molecular Genetics ASCR v.v.i.; Department of Biology of the Cell Nucleus; Prague, Czech Republic
| | - Pavel Marášek
- Institute of Molecular Genetics ASCR v.v.i.; Department of Biology of the Cell Nucleus; Prague, Czech Republic
| | - Enrique Castaño
- Institute of Molecular Genetics ASCR v.v.i.; Department of Biology of the Cell Nucleus; Prague, Czech Republic; Biochemistry and Molecular Plant Biology Department; CICY; Mérida, México
| | - Pavel Hozák
- Institute of Molecular Genetics ASCR v.v.i.; Department of Biology of the Cell Nucleus; Prague, Czech Republic
| |
Collapse
|
36
|
Maity J, Bohr VA, Laskar A, Karmakar P. Transient overexpression of Werner protein rescues starvation induced autophagy in Werner syndrome cells. Biochim Biophys Acta Mol Basis Dis 2014; 1842:2387-94. [PMID: 25257404 DOI: 10.1016/j.bbadis.2014.09.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Revised: 09/02/2014] [Accepted: 09/17/2014] [Indexed: 01/07/2023]
Abstract
Reduced autophagy may be associated with normal and pathological aging. Here we report a link between autophagy and Werner protein (WRNp), mutated in Werner syndrome, the human premature aging Werner syndrome (WS). WRN mutant fibroblast AG11395 and AG05229 respond weakly to starvation induced autophagy compared to normal cells. While the fusion of phagosomes with lysosome is normal, WS cells contain fewer autophagy vacuoles. Cellular starvation autophagy in WS cells is restored after transfection with full length WRN. Further, siRNA mediated silencing of WRN in the normal fibroblast cell line WI-38 results in decreased autophagy and altered expression of autophagy related proteins. Thus, our observations suggest that WRN may have a role in controlling autophagy and hereby cellular maintenance.
Collapse
Affiliation(s)
- Jyotirindra Maity
- Department of Life Science and Biotechnology, Jadavpur University, Kolkata 700032, India
| | - Vilhelm A Bohr
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, United States
| | - Aparna Laskar
- CSIR-Indian Institute of Chemical Biology, Kolkata 700032, India
| | - Parimal Karmakar
- Department of Life Science and Biotechnology, Jadavpur University, Kolkata 700032, India.
| |
Collapse
|
37
|
Rothblum K, Hu Q, Penrod Y, Rothblum LI. Selective inhibition of rDNA transcription by a small-molecule peptide that targets the interface between RNA polymerase I and Rrn3. Mol Cancer Res 2014; 12:1586-96. [PMID: 25033839 DOI: 10.1158/1541-7786.mcr-14-0229] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
UNLABELLED The interface between the polymerase I-associated factor Rrn3 and the 43-kDa subunit of RNA polymerase I is essential to the recruitment of Pol I to the preinitiation complex on the rDNA promoter. In silico analysis identified an evolutionarily conserved 22 amino acid peptide within rpa43 that is both necessary and sufficient to mediate the interaction between rpa43 and Rrn3. This peptide inhibited rDNA transcription in vitro, while a control peptide did not. To determine the effect of the peptide in cultured cells, the peptide was coupled to the HIV TAT peptide to facilitate transduction into cells. The wild-type peptide, but not control peptides, inhibited Pol I transcription and cell division. In addition, the peptide induced cell death, consistent with other observations that "nucleolar stress" results in the death of tumor cells. The 22mer is a small-molecule inhibitor of rDNA transcription that is specific for the interaction between Rrn3 and rpa43, as such it represents an original way to interfere with cell growth. IMPLICATIONS These results demonstrate a potentially novel pharmaceutical target for the therapeutic treatment of cancer cells.
Collapse
Affiliation(s)
- Katrina Rothblum
- Department of Cell Biology, University of Oklahoma College of Medicine, Oklahoma City, Oklahoma
| | - Qiyue Hu
- South Cove Community Health Care Center, Quincy, Massachusetts
| | - Yvonne Penrod
- Department of Cell Biology, University of Oklahoma College of Medicine, Oklahoma City, Oklahoma
| | - Lawrence I Rothblum
- Department of Cell Biology, University of Oklahoma College of Medicine, Oklahoma City, Oklahoma.
| |
Collapse
|
38
|
Dichamp I, Séité P, Agius G, Barbarin A, Beby-Defaux A. Human papillomavirus 16 oncoprotein E7 stimulates UBF1-mediated rDNA gene transcription, inhibiting a p53-independent activity of p14ARF. PLoS One 2014; 9:e96136. [PMID: 24798431 PMCID: PMC4010441 DOI: 10.1371/journal.pone.0096136] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Accepted: 04/03/2014] [Indexed: 11/18/2022] Open
Abstract
High-risk human papillomavirus oncoproteins E6 and E7 play a major role in HPV-related cancers. One of the main functions of E7 is the degradation of pRb, while E6 promotes the degradation of p53, inactivating the p14ARF-p53 pathway. pRb and p14ARF can repress ribosomal DNA (rDNA) transcription in part by targeting the Upstream Binding Factor 1 (UBF1), a key factor in the activation of RNA polymerase I machinery. We showed, through ectopic expression and siRNA silencing of p14ARF and/or E7, that E7 stimulates UBF1-mediated rDNA gene transcription, partly because of increased levels of phosphorylated UBF1, preventing the inhibitory function of p14ARF. Unexpectedly, activation of rDNA gene transcription was higher in cells co-expressing p14ARF and E7, compared to cells expressing E7 alone. We did not find a difference in P-UBF1 levels that could explain this data. However, p14ARF expression induced E7 to accumulate into the nucleolus, where rDNA transcription takes place, providing an opportunity for E7 to interact with nucleolar proteins involved in this process. GST-pull down and co-immunoprecipitation assays showed interactions between p14ARF, UBF1 and E7, although p14ARF and E7 are not able to directly interact. Co-expression of a pRb-binding-deficient mutant (E7C24G) and p14ARF resulted in EC24G nucleolar accumulation, but not in a significant higher activation of rDNA transcription, suggesting that the inactivation of pRb is involved in this phenomenon. Thus, p14ARF fails to prevent E7-mediated UBF1 phosphorylation, but could facilitate nucleolar pRb inactivation by targeting E7 to the nucleolus. While others have reported that p19ARF, the mouse homologue of p14ARF, inhibits some functions of E7, we showed that E7 inhibits a p53-independent function of p14ARF. These results point to a mutually functional interaction between p14ARF and E7 that might partly explain why the sustained p14ARF expression observed in most cervical pre-malignant lesions and malignancies may be ineffective.
Collapse
Affiliation(s)
- Isabelle Dichamp
- Unité de Virologie, Centre Hospitalier Universitaire de Poitiers, Faculté de Médecine et Pharmacie, Poitiers, France
| | - Paule Séité
- Equipe Emergente 2RCT «Récepteurs, Régulations, Cellules Tumorales», Université de Poitiers, Poitiers, France
| | - Gérard Agius
- Unité de Virologie, Centre Hospitalier Universitaire de Poitiers, Faculté de Médecine et Pharmacie, Poitiers, France
| | - Alice Barbarin
- Equipe Emergente 2RCT «Récepteurs, Régulations, Cellules Tumorales», Université de Poitiers, Poitiers, France
| | - Agnès Beby-Defaux
- Unité de Virologie, Centre Hospitalier Universitaire de Poitiers, Faculté de Médecine et Pharmacie, Poitiers, France
- Equipe Emergente 2RCT «Récepteurs, Régulations, Cellules Tumorales», Université de Poitiers, Poitiers, France
- * E-mail:
| |
Collapse
|
39
|
Ponti D, Bellenchi GC, Puca R, Bastianelli D, Maroder M, Ragona G, Roussel P, Thiry M, Mercola D, Calogero A. The transcription factor EGR1 localizes to the nucleolus and is linked to suppression of ribosomal precursor synthesis. PLoS One 2014; 9:e96037. [PMID: 24787739 PMCID: PMC4006901 DOI: 10.1371/journal.pone.0096037] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Accepted: 04/03/2014] [Indexed: 01/13/2023] Open
Abstract
EGR1 is an immediate early gene with a wide range of activities as transcription factor, spanning from regulation of cell growth to differentiation. Numerous studies show that EGR1 either promotes the proliferation of stimulated cells or suppresses the tumorigenic growth of transformed cells. Upon interaction with ARF, EGR1 is sumoylated and acquires the ability to bind to specific targets such as PTEN and in turn to regulate cell growth. ARF is mainly localized to the periphery of nucleolus where is able to negatively regulate ribosome biogenesis. Since EGR1 colocalizes with ARF under IGF-1 stimulation we asked the question of whether EGR1 also relocate to the nucleolus to interact with ARF. Here we show that EGR1 colocalizes with nucleolar markers such as fibrillarin and B23 in the presence of ARF. Western analysis of nucleolar extracts from HeLa cells was used to confirm the presence of EGR1 in the nucleolus mainly as the 100 kDa sumoylated form. We also show that the level of the ribosomal RNA precursor 47S is inversely correlated to the level of EGR1 transcripts. The EGR1 iseffective to regulate the synthesis of the 47S rRNA precursor. Then we demonstrated that EGR1 binds to the Upstream Binding Factor (UBF) leading us to hypothesize that the regulating activity of EGR1 is mediated by its interaction within the transcriptional complex of RNA polymerase I. These results confirm the presence of EGR1 in the nucleolus and point to a role for EGR1 in the control of nucleolar metabolism.
Collapse
Affiliation(s)
- Donatella Ponti
- Department of Medico-Surgical Sciences and Biotechnologies, University of Rome La Sapienza, Latina, Italy
| | | | - Rosa Puca
- Department of Medico-Surgical Sciences and Biotechnologies, University of Rome La Sapienza, Latina, Italy
| | - Daniela Bastianelli
- Department of Medico-Surgical Sciences and Biotechnologies, University of Rome La Sapienza, Latina, Italy
| | - Marella Maroder
- Department of Medico-Surgical Sciences and Biotechnologies, University of Rome La Sapienza, Latina, Italy
| | - Giuseppe Ragona
- Department of Medico-Surgical Sciences and Biotechnologies, University of Rome La Sapienza, Latina, Italy
| | - Pascal Roussel
- RNA Biology, FRE 3402 CNRS-Universitè Pierre et Marie Curie, Paris, France
| | - Marc Thiry
- Unit of Cell Biology, GIGA-Neuroscience, University of Liege, CHU SartTilman, Liege, Belgium
| | - Dan Mercola
- Department of Pathology and Laboratory Medicine, University of California, Irvine, California, United States of America
| | - Antonella Calogero
- Department of Medico-Surgical Sciences and Biotechnologies, University of Rome La Sapienza, Latina, Italy
- * E-mail:
| |
Collapse
|
40
|
Quin JE, Devlin JR, Cameron D, Hannan KM, Pearson RB, Hannan RD. Targeting the nucleolus for cancer intervention. Biochim Biophys Acta Mol Basis Dis 2014; 1842:802-16. [PMID: 24389329 DOI: 10.1016/j.bbadis.2013.12.009] [Citation(s) in RCA: 170] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Accepted: 12/17/2013] [Indexed: 12/17/2022]
Abstract
The contribution of the nucleolus to cancer is well established with respect to its traditional role in facilitating ribosome biogenesis and proliferative capacity. More contemporary studies however, infer that nucleoli contribute a much broader role in malignant transformation. Specifically, extra-ribosomal functions of the nucleolus position it as a central integrator of cellular proliferation and stress signaling, and are emerging as important mechanisms for modulating how oncogenes and tumor suppressors operate in normal and malignant cells. The dependence of certain tumor cells to co-opt nucleolar processes to maintain their cancer phenotypes has now clearly been demonstrated by the application of small molecule inhibitors of RNA Polymerase I to block ribosomal DNA transcription and disrupt nucleolar function (Bywater et al., 2012 [1]). These drugs, which selectively kill tumor cells in vivo while sparing normal cells, have now progressed to clinical trials. It is likely that we have only just begun to scratch the surface of the potential of the nucleolus as a new target for cancer therapy, with "suppression of nucleolar stress" representing an emerging "hallmark" of cancer. This article is part of a Special Issue entitled: Role of the Nucleolus in Human Disease.
Collapse
Affiliation(s)
- Jaclyn E Quin
- Oncogenic Signalling and Growth Control Program, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia; Department of Biochemistry and Molecular Biology, The University of Melbourne, Parkville, Victoria, Australia
| | - Jennifer R Devlin
- Oncogenic Signalling and Growth Control Program, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia; Department of Biochemistry and Molecular Biology, The University of Melbourne, Parkville, Victoria, Australia
| | - Donald Cameron
- Oncogenic Signalling and Growth Control Program, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
| | - Kate M Hannan
- Oncogenic Signalling and Growth Control Program, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia; Department of Biochemistry and Molecular Biology, The University of Melbourne, Parkville, Victoria, Australia
| | - Richard B Pearson
- Oncogenic Signalling and Growth Control Program, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia; Department of Biochemistry and Molecular Biology, The University of Melbourne, Parkville, Victoria, Australia; Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, Victoria, Australia; Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
| | - Ross D Hannan
- Oncogenic Signalling and Growth Control Program, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia; Department of Biochemistry and Molecular Biology, The University of Melbourne, Parkville, Victoria, Australia; Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, Victoria, Australia; Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia; Department of Pathology, The University of Melbourne, Parkville, Victoria, Australia; School of Biomedical Sciences, The University of Queensland, St Lucia, Queensland, Australia.
| |
Collapse
|
41
|
Sarshad AA, Percipalle P. New Insight into Role of Myosin Motors for Activation of RNA Polymerases. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2014; 311:183-230. [DOI: 10.1016/b978-0-12-800179-0.00004-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
42
|
Ono M, Yamada K, Endo A, Avolio F, Lamond AI. Analysis of human protein replacement stable cell lines established using snoMEN-PR vector. PLoS One 2013; 8:e62305. [PMID: 23638031 PMCID: PMC3636044 DOI: 10.1371/journal.pone.0062305] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Accepted: 03/19/2013] [Indexed: 11/20/2022] Open
Abstract
The study of the function of many human proteins is often hampered by technical limitations, such as cytotoxicity and phenotypes that result from overexpression of the protein of interest together with the endogenous version. Here we present the snoMEN (snoRNA Modulator of gene ExpressioN) vector technology for generating stable cell lines where expression of the endogenous protein can be reduced and replaced by an exogenous protein, such as a fluorescent protein (FP)-tagged version. SnoMEN are snoRNAs engineered to contain complementary sequences that can promote knock-down of targeted RNAs. We have established and characterised two such partial protein replacement human cell lines (snoMEN-PR). Quantitative mass spectrometry was used to analyse the specificity of knock-down and replacement at the protein level and also showed an increased pull-down efficiency of protein complexes containing exogenous, tagged proteins in the protein replacement cell lines, as compared with conventional co-expression strategies. The snoMEN approach facilitates the study of mammalian proteins, particularly those that have so far been difficult to investigate by exogenous expression and has wide applications in basic and applied gene-expression research.
Collapse
Affiliation(s)
- Motoharu Ono
- Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Kayo Yamada
- Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Akinori Endo
- Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Fabio Avolio
- Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Angus I. Lamond
- Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dundee, United Kingdom
- * E-mail:
| |
Collapse
|
43
|
P19ARF and RasV¹² offer opposing regulation of DHX33 translation to dictate tumor cell fate. Mol Cell Biol 2013; 33:1594-607. [PMID: 23401854 DOI: 10.1128/mcb.01220-12] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
DHX33 is a pivotal DEAH-box RNA helicase in the multistep process of RNA polymerase I-directed transcription of the ribosomal DNA locus. We explored the regulation of DHX33 expression by Ras(V12) and ARF to determine DHX33's role in sensing these opposing signals to regulate ribosome biogenesis. In wild-type primary fibroblasts, Ras(V12) infection induced a transient increase in DHX33 protein level, as well as an rRNA transcriptional rate that was eventually suppressed by a delayed activation of the ARF/p53 pathway. DHX33 expression was exclusively controlled at the level of translation. ARF caused a dramatic reduction in polysome-associated DHX33 mRNAs, while Ras(V12) led to a complete shift of existing DHX33 mRNAs to actively translating polysomes. The translation of DHX33 by Ras(V12) was sensitive to inhibitors of phosphatidylinositol 3-kinase, mTOR, and mitogen-activated protein and was pivotal for enhanced rRNA transcription and enhanced overall cellular protein translation. In addition, DHX33 knockdown abolished Ras(V12)-induced rRNA transcription and protein translation and prevented both the in vitro and in vivo transforming properties of oncogenic Ras(V12). Our results directly implicate DHX33 as a crucial player in establishing rRNA synthesis rates in the face of Ras(V12) or ARF signals, adjusting ribosome biogenesis to match the appropriate growth or antigrowth signals.
Collapse
|
44
|
Stepanchick A, Zhi H, Cavanaugh AH, Rothblum K, Schneider DA, Rothblum LI. DNA binding by the ribosomal DNA transcription factor rrn3 is essential for ribosomal DNA transcription. J Biol Chem 2013; 288:9135-44. [PMID: 23393135 DOI: 10.1074/jbc.m112.444265] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The human homologue of yeast Rrn3 is an RNA polymerase I-associated transcription factor that is essential for ribosomal DNA (rDNA) transcription. The generally accepted model is that Rrn3 functions as a bridge between RNA polymerase I and the transcription factors bound to the committed template. In this model Rrn3 would mediate an interaction between the mammalian Rrn3-polymerase I complex and SL1, the rDNA transcription factor that binds to the core promoter element of the rDNA. In the course of studying the role of Rrn3 in recruitment, we found that Rrn3 was in fact a DNA-binding protein. Analysis of the sequence of Rrn3 identified a domain with sequence similarity to the DNA binding domain of heat shock transcription factor 2. Randomization, or deletion, of the amino acids in this region in Rrn3, amino acids 382-400, abrogated its ability to bind DNA, indicating that this domain was an important contributor to DNA binding by Rrn3. Control experiments demonstrated that these mutant Rrn3 constructs were capable of interacting with both rpa43 and SL1, two other activities demonstrated to be essential for Rrn3 function. However, neither of these Rrn3 mutants was capable of functioning in transcription in vitro. Moreover, although wild-type human Rrn3 complemented a yeast rrn3-ts mutant, the DNA-binding site mutant did not. These results demonstrate that DNA binding by Rrn3 is essential for transcription by RNA polymerase I.
Collapse
Affiliation(s)
- Ann Stepanchick
- Sigfried and Janet Weis Center for Research, Geisinger Clinic, Danville, PA 17821, USA
| | | | | | | | | | | |
Collapse
|
45
|
Goodfellow SJ, Zomerdijk JCBM. Basic mechanisms in RNA polymerase I transcription of the ribosomal RNA genes. Subcell Biochem 2013; 61:211-36. [PMID: 23150253 PMCID: PMC3855190 DOI: 10.1007/978-94-007-4525-4_10] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
RNA Polymerase (Pol) I produces ribosomal (r)RNA, an essential component of the cellular protein synthetic machinery that drives cell growth, underlying many fundamental cellular processes. Extensive research into the mechanisms governing transcription by Pol I has revealed an intricate set of control mechanisms impinging upon rRNA production. Pol I-specific transcription factors guide Pol I to the rDNA promoter and contribute to multiple rounds of transcription initiation, promoter escape, elongation and termination. In addition, many accessory factors are now known to assist at each stage of this transcription cycle, some of which allow the integration of transcriptional activity with metabolic demands. The organisation and accessibility of rDNA chromatin also impinge upon Pol I output, and complex mechanisms ensure the appropriate maintenance of the epigenetic state of the nucleolar genome and its effective transcription by Pol I. The following review presents our current understanding of the components of the Pol I transcription machinery, their functions and regulation by associated factors, and the mechanisms operating to ensure the proper transcription of rDNA chromatin. The importance of such stringent control is demonstrated by the fact that deregulated Pol I transcription is a feature of cancer and other disorders characterised by abnormal translational capacity.
Collapse
Affiliation(s)
- Sarah J. Goodfellow
- Wellcome Trust Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee , Dundee DD1 5EH , UK
| | - Joost C. B. M. Zomerdijk
- Wellcome Trust Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee , Dundee DD1 5EH , UK
| |
Collapse
|
46
|
Hannan KM, Sanij E, Rothblum LI, Hannan RD, Pearson RB. Dysregulation of RNA polymerase I transcription during disease. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2012; 1829:342-60. [PMID: 23153826 DOI: 10.1016/j.bbagrm.2012.10.014] [Citation(s) in RCA: 100] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Revised: 10/30/2012] [Accepted: 10/31/2012] [Indexed: 12/13/2022]
Abstract
Transcription of the ribosomal RNA genes by the dedicated RNA polymerase I enzyme and subsequent processing of the ribosomal RNA are fundamental control steps in the synthesis of functional ribosomes. Dysregulation of Pol I transcription and ribosome biogenesis is linked to the etiology of a broad range of human diseases. Diseases caused by loss of function mutations in the molecular constituents of the ribosome, or factors intimately associated with RNA polymerase I transcription and processing are collectively termed ribosomopathies. Ribosomopathies are generally rare and treatment options are extremely limited tending to be more palliative than curative. Other more common diseases are associated with profound changes in cellular growth such as cardiac hypertrophy, atrophy or cancer. In contrast to ribosomopathies, altered RNA polymerase I transcriptional activity in these diseases largely results from dysregulated upstream oncogenic pathways or by direct modulation by oncogenes or tumor suppressors at the level of the RNA polymerase I transcription apparatus itself. Ribosomopathies associated with mutations in ribosomal proteins and ribosomal RNA processing or assembly factors have been covered by recent excellent reviews. In contrast, here we review our current knowledge of human diseases specifically associated with dysregulation of RNA polymerase I transcription and its associated regulatory apparatus, including some cases where this dysregulation is directly causative in disease. We will also provide insight into and discussion of possible therapeutic approaches to treat patients with dysregulated RNA polymerase I transcription. This article is part of a Special Issue entitled: Transcription by Odd Pols.
Collapse
Affiliation(s)
- K M Hannan
- Oncogenic Signalling and Growth Control Program, Peter MacCallum Cancer Centre, Locked Bag 1, A'Beckett St, Melbourne, Victoria 8006, Australia
| | | | | | | | | |
Collapse
|
47
|
Abstract
In the Caenorhabditis elegans nematode, the oocyte nucleolus disappears prior to fertilization. We have now investigated the re-formation of the nucleolus in the early embryo of this model organism by immunostaining for fibrillarin and DAO-5, a putative NOLC1/Nopp140 homolog involved in ribosome assembly. We find that labeled nucleoli first appear in somatic cells at around the 8-cell stage, at a time when transcription of the embryonic genome begins. Quantitative analysis of radial positioning showed the nucleolus to be localized at the nuclear periphery in a majority of early embryonic nuclei. At the ultrastructural level, the embryonic nucleolus appears to be composed of a relatively homogenous core surrounded by a crescent-shaped granular structure. Prior to embryonic genome activation, fibrillarin and DAO-5 staining is seen in numerous small nucleoplasmic foci. This staining pattern persists in the germline up to the ∼100-cell stage, until the P4 germ cell divides to give rise to the Z2/Z3 primordial germ cells and embryonic transcription is activated in this lineage. In the ncl-1 mutant, which is characterized by increased transcription of rDNA, DAO-5-labeled nucleoli are already present at the 2-cell stage. Our results suggest a link between the activation of transcription and the initial formation of nucleoli in the C. elegans embryo.
Collapse
|
48
|
Fogarty NME, Mayhew TM, Ferguson-Smith AC, Burton GJ. A quantitative analysis of transcriptionally active syncytiotrophoblast nuclei across human gestation. J Anat 2011; 219:601-10. [PMID: 21883201 DOI: 10.1111/j.1469-7580.2011.01417.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The syncytiotrophoblast (STB) epithelial covering of the human placenta is a unique terminally differentiated, multi-nucleated syncytium. No mitotic bodies are observed in the STB, which is sustained by continuous fusion of underlying cytotrophoblast cells (CTB). As a result, STB nuclei are of different ages. Morphologically, they display varying degrees of chromatin compaction, suggesting progressive maturational changes. Until recently, it was thought that STB nuclei were transcriptionally inactive, with all the mRNAs required by the syncytium being incorporated upon fusion of CTB. However, recent research has shown the presence of the active form of RNA polymerase II (RNA Pol II) in some STB nuclei. In this study, we confirm the presence of transcriptional activity in STB nuclei by demonstrating immunoreactivity for a transcription factor and an RNA polymerase I (RNA Pol I) co-factor, phospho-cAMP response element-binding protein and phospho-upstream binding factor, respectively. We also show, through immunoco-localisation studies, that a proportion of STB nuclei are both RNA Pol I and II transcriptionally active. Finally, we quantify the numerical densities of nuclei immunopositive and immunonegative for RNA Pol II in the STB of normal placentas of 11-39 weeks gestational age using an unbiased stereological counting tool, the physical disector. These data were combined with estimates of the volume of trophoblast to calculate total numbers of both types of nuclei at each gestational age. We found no correlation between gestational age and the numerical density of RNA Pol II-positive nuclei in the villous trophoblast (r = 0.39, P > 0.05). As the number of STB nuclei increases exponentially during gestation, we conclude that the number of transcriptionally active nuclei increases in proportion to trophoblast volume. The ratio of active to inactive nuclei remains constant at 3.9:1. These findings confirm that the majority of STB nuclei have intrinsic transcriptional activity, and that the STB is not dependent on CTB fusion for the provision of transcripts.
Collapse
Affiliation(s)
- N M E Fogarty
- Department Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK
| | | | | | | |
Collapse
|
49
|
Depletion of insulin receptor substrate 2 reverses oncogenic transformation induced by v-src. Acta Pharmacol Sin 2011; 32:611-8. [PMID: 21532614 DOI: 10.1038/aps.2011.18] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
AIM To investigate the role of insulin receptor substrate 2 (IRS-2) in oncogenic transformation induced by v-src. METHODS IRS-2 gene was silenced using small interfering RNAs (siRNAs). Nuclear translocation and interaction of IRS-2 with v-src was determined using subcellular fractionation, confocal microscopy, and immunoprecipitation. The activity of the cyclin D1 promoter and r-DNA promoter was measured with a luciferase assay. RESULTS Depletion of IRS-2 inhibited R-/v-src cell growth and reverse the oncogenic transformation. IRS-2 bound to src via its two PI3-K binding sites, which are critical for activities involved in the transformation. Nuclear IRS-2 occupied the cyclin D1 and rDNA promoters. The combination of IRS-2 and v-src increased the activity of the two promoters, especially the rDNA promoter. CONCLUSION Depletion of insulin receptor substrate 2 could reverse oncogenic transformation induced by v-src.
Collapse
|
50
|
Erk in kidney diseases. JOURNAL OF SIGNAL TRANSDUCTION 2011; 2011:768512. [PMID: 21776388 PMCID: PMC3135240 DOI: 10.1155/2011/768512] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/07/2010] [Accepted: 02/01/2011] [Indexed: 11/17/2022]
Abstract
Acute or chronic kidney injury results from various insults and pathological conditions, and is accompanied by activation of compensatory repair mechanisms. Both insults and repair mechanisms are initiated by circulating factors, whose cellular effects are mediated by activation selective signal transduction pathways. Two main signal transduction pathways are activated during these processes, the phosphatidylinositol 3' kinase (PI-3K)/mammalian target of rapamycin (mTOR) and the mitogen-activated protein kinase (MAPK) cascades. This review will focus on the latter, and more specifically on the role of extracellular signal-regulated kinase (ERK) cascade in kidney injury and repair.
Collapse
|