1
|
Suresh HG, Bonneil E, Albert B, Dominique C, Costanzo M, Pons C, David Masinas MP, Shuteriqi E, Shore D, Henras AK, Thibault P, Boone C, Andrews BJ. K29-linked unanchored polyubiquitin chains disrupt ribosome biogenesis and direct ribosomal proteins to the Intranuclear Quality control compartment (INQ). BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.03.539259. [PMID: 37205480 PMCID: PMC10187189 DOI: 10.1101/2023.05.03.539259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Ribosome assembly requires precise coordination between the production and assembly of ribosomal components. Mutations in ribosomal proteins that inhibit the assembly process or ribosome function are often associated with Ribosomopathies, some of which are linked to defects in proteostasis. In this study, we examine the interplay between several yeast proteostasis enzymes, including deubiquitylases (DUBs), Ubp2 and Ubp14, and E3 ligases, Ufd4 and Hul5, and we explore their roles in the regulation of the cellular levels of K29-linked unanchored polyubiquitin (polyUb) chains. Accumulating K29-linked unanchored polyUb chains associate with maturing ribosomes to disrupt their assembly, activate the Ribosome assembly stress response (RASTR), and lead to the sequestration of ribosomal proteins at the Intranuclear Quality control compartment (INQ). These findings reveal the physiological relevance of INQ and provide insights into mechanisms of cellular toxicity associated with Ribosomopathies.
Collapse
|
2
|
Martínez-Férriz A, Ferrando A, Fathinajafabadi A, Farràs R. Ubiquitin-mediated mechanisms of translational control. Semin Cell Dev Biol 2022; 132:146-154. [PMID: 34952788 DOI: 10.1016/j.semcdb.2021.12.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 12/16/2021] [Accepted: 12/17/2021] [Indexed: 12/15/2022]
Abstract
mRNAs translation to proteins constitutes an important step of cellular gene expression that is highly regulated in response to different extracellular stimuli and stress situations. The fine control of protein synthesis is carried out both qualitatively and quantitatively, depending on the cellular demand at each moment. Post-translational modifications, in turn regulated by intracellular signaling pathways, play a key role in translation regulation. Among them, ubiquitination, whose role is becoming increasingly important in the control of translation, determines a correct balance between protein synthesis and degradation. In this review we focus on the role of ubiquitination (both degradative K48-linkage type and non-degradative K63-linkage type and monoubiquitination) in eukaryotic translation, both at the pre-translational level during the biogenesis/degradation of the components of translational machinery as well as at the co-translational level under stressful conditions. We also discuss other ubiquitin-dependent regulatory mechanisms of mRNA protection and resumption of translation after stress removal, where the ubiquitination of ribosomal proteins and associated regulatory proteins play an important role in the global rhythm of translation.
Collapse
Affiliation(s)
- Arantxa Martínez-Férriz
- Oncogenic Signalling Laboratory, Centro de Investigación Príncipe Felipe (CIPF), Valencia, Spain
| | - Alejandro Ferrando
- Instituto de Biología Molecular y Celular de Plantas CSIC-Universidad Politécnica de Valencia, Valencia, Spain
| | - Alihamze Fathinajafabadi
- Oncogenic Signalling Laboratory, Centro de Investigación Príncipe Felipe (CIPF), Valencia, Spain.
| | - Rosa Farràs
- Oncogenic Signalling Laboratory, Centro de Investigación Príncipe Felipe (CIPF), Valencia, Spain.
| |
Collapse
|
3
|
Dörner K, Badertscher L, Horváth B, Hollandi R, Molnár C, Fuhrer T, Meier R, Sárazová M, van den Heuvel J, Zamboni N, Horvath P, Kutay U. Genome-wide RNAi screen identifies novel players in human 60S subunit biogenesis including key enzymes of polyamine metabolism. Nucleic Acids Res 2022; 50:2872-2888. [PMID: 35150276 PMCID: PMC8934630 DOI: 10.1093/nar/gkac072] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 01/18/2022] [Accepted: 01/25/2022] [Indexed: 12/19/2022] Open
Abstract
Ribosome assembly is an essential process that is linked to human congenital diseases and tumorigenesis. While great progress has been made in deciphering mechanisms governing ribosome biogenesis in eukaryotes, an inventory of factors that support ribosome synthesis in human cells is still missing, in particular regarding the maturation of the large 60S subunit. Here, we performed a genome-wide RNAi screen using an imaging-based, single cell assay to unravel the cellular machinery promoting 60S subunit assembly in human cells. Our screen identified a group of 310 high confidence factors. These highlight the conservation of the process across eukaryotes and reveal the intricate connectivity of 60S subunit maturation with other key cellular processes, including splicing, translation, protein degradation, chromatin organization and transcription. Intriguingly, we also identified a cluster of hits comprising metabolic enzymes of the polyamine synthesis pathway. We demonstrate that polyamines, which have long been used as buffer additives to support ribosome assembly in vitro, are required for 60S maturation in living cells. Perturbation of polyamine metabolism results in early defects in 60S but not 40S subunit maturation. Collectively, our data reveal a novel function for polyamines in living cells and provide a rich source for future studies on ribosome synthesis.
Collapse
Affiliation(s)
- Kerstin Dörner
- Institute of Biochemistry, Department of Biology, ETH Zurich, 8093 Zurich, Switzerland.,Molecular Life Sciences Ph.D. Program, 8057 Zurich, Switzerland
| | - Lukas Badertscher
- Institute of Biochemistry, Department of Biology, ETH Zurich, 8093 Zurich, Switzerland.,Molecular Life Sciences Ph.D. Program, 8057 Zurich, Switzerland
| | - Bianka Horváth
- Institute of Biochemistry, Department of Biology, ETH Zurich, 8093 Zurich, Switzerland.,Molecular Life Sciences Ph.D. Program, 8057 Zurich, Switzerland
| | - Réka Hollandi
- Synthetic and Systems Biology Unit, Biological Research Center, 6726 Szeged, Hungary
| | - Csaba Molnár
- Synthetic and Systems Biology Unit, Biological Research Center, 6726 Szeged, Hungary
| | - Tobias Fuhrer
- Institute of Molecular Systems Biology, Department of Biology, ETH Zürich, 8093 Zürich, Switzerland
| | - Roger Meier
- ScopeM, ETH Zürich, 8093 Zürich, Switzerland
| | - Marie Sárazová
- Institute of Biochemistry, Department of Biology, ETH Zurich, 8093 Zurich, Switzerland
| | - Jasmin van den Heuvel
- Institute of Biochemistry, Department of Biology, ETH Zurich, 8093 Zurich, Switzerland
| | - Nicola Zamboni
- Institute of Molecular Systems Biology, Department of Biology, ETH Zürich, 8093 Zürich, Switzerland
| | - Peter Horvath
- Synthetic and Systems Biology Unit, Biological Research Center, 6726 Szeged, Hungary.,Institute for Molecular Medicine Finland, University of Helsinki, 00014 Helsinki, Finland
| | - Ulrike Kutay
- Institute of Biochemistry, Department of Biology, ETH Zurich, 8093 Zurich, Switzerland
| |
Collapse
|
4
|
Zhan X, Lu M, Yang L, Yang J, Zhan X, Zheng S, Guo Y, Li B, Wen S, Li J, Li N. Ubiquitination-mediated molecular pathway alterations in human lung squamous cell carcinomas identified by quantitative ubiquitinomics. Front Endocrinol (Lausanne) 2022; 13:970843. [PMID: 36187110 PMCID: PMC9520991 DOI: 10.3389/fendo.2022.970843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 08/25/2022] [Indexed: 11/13/2022] Open
Abstract
Abnormal ubiquitination is extensively associated with cancers. To investigate human lung cancer ubiquitination and its potential functions, quantitative ubiquitinomics was carried out between human lung squamous cell carcinoma (LSCC) and control tissues, which characterized a total of 627 ubiquitin-modified proteins (UPs) and 1209 ubiquitinated lysine sites. Those UPs were mainly involved in cell adhesion, signal transduction, and regulations of ribosome complex and proteasome complex. Thirty three UPs whose genes were also found in TCGA database were significantly related to overall survival of LSCC. Six significant networks and 234 hub molecules were obtained from the protein-protein interaction (PPI) analysis of those 627 UPs. KEGG pathway analysis of those UPs revealed 47 statistically significant pathways, and most of which were tumor-associated pathways such as mTOR, HIF-1, PI3K-Akt, and Ras signaling pathways, and intracellular protein turnover-related pathways such as ribosome complex, ubiquitin-mediated proteolysis, ER protein processing, and proteasome complex pathways. Further, the relationship analysis of ubiquitination and differentially expressed proteins shows that ubiquitination regulates two aspects of protein turnover - synthesis and degradation. This study provided the first profile of UPs and molecular networks in LSCC tissue, which is the important resource to insight into new mechanisms, and to identify new biomarkers and therapeutic targets/drugs to treat LSCC.
Collapse
Affiliation(s)
- Xianquan Zhan
- Shandong Key Laboratory of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, China
- Medical Science and Technology Innovation Center, Shandong First Medical University, Jinan, China
- *Correspondence: Xianquan Zhan,
| | - Miaolong Lu
- Medical Science and Technology Innovation Center, Shandong First Medical University, Jinan, China
- Key Laboratory of Cancer Proteomics of Chinese Ministry of Health, Xiangya Hospital, Central South University, Changsha, China
| | - Lamei Yang
- Medical Science and Technology Innovation Center, Shandong First Medical University, Jinan, China
| | - Jingru Yang
- Medical Science and Technology Innovation Center, Shandong First Medical University, Jinan, China
| | - Xiaohan Zhan
- Medical Science and Technology Innovation Center, Shandong First Medical University, Jinan, China
- Key Laboratory of Cancer Proteomics of Chinese Ministry of Health, Xiangya Hospital, Central South University, Changsha, China
| | - Shu Zheng
- Medical Science and Technology Innovation Center, Shandong First Medical University, Jinan, China
| | - Yuna Guo
- Medical Science and Technology Innovation Center, Shandong First Medical University, Jinan, China
| | - Biao Li
- Medical Science and Technology Innovation Center, Shandong First Medical University, Jinan, China
- Key Laboratory of Cancer Proteomics of Chinese Ministry of Health, Xiangya Hospital, Central South University, Changsha, China
| | - Siqi Wen
- Medical Science and Technology Innovation Center, Shandong First Medical University, Jinan, China
- Key Laboratory of Cancer Proteomics of Chinese Ministry of Health, Xiangya Hospital, Central South University, Changsha, China
| | - Jiajia Li
- Medical Science and Technology Innovation Center, Shandong First Medical University, Jinan, China
- Key Laboratory of Cancer Proteomics of Chinese Ministry of Health, Xiangya Hospital, Central South University, Changsha, China
| | - Na Li
- Shandong Key Laboratory of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, China
- Medical Science and Technology Innovation Center, Shandong First Medical University, Jinan, China
| |
Collapse
|
5
|
Martín-Villanueva S, Gutiérrez G, Kressler D, de la Cruz J. Ubiquitin and Ubiquitin-Like Proteins and Domains in Ribosome Production and Function: Chance or Necessity? Int J Mol Sci 2021; 22:ijms22094359. [PMID: 33921964 PMCID: PMC8122580 DOI: 10.3390/ijms22094359] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 04/19/2021] [Accepted: 04/20/2021] [Indexed: 12/11/2022] Open
Abstract
Ubiquitin is a small protein that is highly conserved throughout eukaryotes. It operates as a reversible post-translational modifier through a process known as ubiquitination, which involves the addition of one or several ubiquitin moieties to a substrate protein. These modifications mark proteins for proteasome-dependent degradation or alter their localization or activity in a variety of cellular processes. In most eukaryotes, ubiquitin is generated by the proteolytic cleavage of precursor proteins in which it is fused either to itself, constituting a polyubiquitin precursor, or as a single N-terminal moiety to ribosomal proteins, which are practically invariably eL40 and eS31. Herein, we summarize the contribution of the ubiquitin moiety within precursors of ribosomal proteins to ribosome biogenesis and function and discuss the biological relevance of having maintained the explicit fusion to eL40 and eS31 during evolution. There are other ubiquitin-like proteins, which also work as post-translational modifiers, among them the small ubiquitin-like modifier (SUMO). Both ubiquitin and SUMO are able to modify ribosome assembly factors and ribosomal proteins to regulate ribosome biogenesis and function. Strikingly, ubiquitin-like domains are also found within two ribosome assembly factors; hence, the functional role of these proteins will also be highlighted.
Collapse
Affiliation(s)
- Sara Martín-Villanueva
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, 41009 Seville, Spain;
- Departamento de Genética, Universidad de Sevilla, 41013 Seville, Spain;
| | - Gabriel Gutiérrez
- Departamento de Genética, Universidad de Sevilla, 41013 Seville, Spain;
| | - Dieter Kressler
- Unit of Biochemistry, Department of Biology, University of Fribourg, CH-1700 Fribourg, Switzerland
- Correspondence: (D.K.); (J.d.l.C.); Tel.: +41-26-300-86-45 (D.K.); +34-955-923-126 (J.d.l.C.)
| | - Jesús de la Cruz
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, 41009 Seville, Spain;
- Departamento de Genética, Universidad de Sevilla, 41013 Seville, Spain;
- Correspondence: (D.K.); (J.d.l.C.); Tel.: +41-26-300-86-45 (D.K.); +34-955-923-126 (J.d.l.C.)
| |
Collapse
|
6
|
Yehia L, Liu D, Fu S, Iyer P, Eng C. Non-canonical role of wild-type SEC23B in the cellular stress response pathway. Cell Death Dis 2021; 12:304. [PMID: 33753724 PMCID: PMC7985502 DOI: 10.1038/s41419-021-03589-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 02/25/2021] [Accepted: 03/01/2021] [Indexed: 11/21/2022]
Abstract
While germline recessive loss-of-function mutations in SEC23B in humans cause a rare form of anaemia, heterozygous change-of-function mutations result in increased predisposition to cancer. SEC23B encodes SEC23 homologue B, a component of coat protein complex II (COPII), which canonically transports proteins from the endoplasmic reticulum (ER) to the Golgi. Despite the association of SEC23B with anaemia and cancer, the precise pathophysiology of these phenotypic outcomes remains unknown. Recently, we reported that mutant SEC23B has non-canonical COPII-independent function, particularly within the ER stress and ribosome biogenesis pathways, and that may contribute to the pathobiology of cancer predisposition. In this study, we hypothesized that wild-type SEC23B has a baseline function within such cellular stress response pathways, with the mutant protein reflecting exaggerated effects. Here, we show that the wild-type SEC23B protein localizes to the nucleus in addition to classical distribution at the ER/Golgi interface and identify multiple putative nuclear localization and export signals regulating nuclear-cytoplasmic transport. Unexpectedly, we show that, independently of COPII, wild-type SEC23B can also localize to cell nucleoli under proteasome inhibition conditions, with distinct distribution patterns compared to mutant cells. Unbiased proteomic analyses through mass spectrometry further revealed that wild-type SEC23B interacts with a subset of nuclear proteins, in addition to central proteins in the ER stress, protein ubiquitination, and EIF2 signalling pathways. We validate the genotype-specific differential SEC23B-UBA52 (ribosomal protein RPL40) interaction. Finally, utilizing patient-derived lymphoblastoid cell lines harbouring either wild-type or mutant SEC23B, we show that SEC23B levels increase in response to ER stress, further corroborating its role as a cellular stress response sensor and/or effector. Overall, these observations suggest that SEC23B, irrespective of mutation status, has unexplored roles in the cellular stress response pathway, with implications relevant to cancer and beyond that, CDAII and normal cell biology.
Collapse
Affiliation(s)
- Lamis Yehia
- Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Darren Liu
- Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
- Cleveland Clinic Lerner College of Medicine, Cleveland, OH, USA
| | - Shuai Fu
- Cleveland Clinic Lerner College of Medicine, Cleveland, OH, USA
- Department of Genetics and Genome Sciences, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Pranav Iyer
- Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
- Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ, USA
| | - Charis Eng
- Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA.
- Cleveland Clinic Lerner College of Medicine, Cleveland, OH, USA.
- Department of Genetics and Genome Sciences, Case Western Reserve University School of Medicine, Cleveland, OH, USA.
- Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH, USA.
- Germline High Risk Cancer Focus Group, Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH, USA.
| |
Collapse
|
7
|
Mende H, Müller S. Surveillance of nucleolar homeostasis and ribosome maturation by autophagy and the ubiquitin-proteasome system. Matrix Biol 2021; 100-101:30-38. [PMID: 33556475 DOI: 10.1016/j.matbio.2021.02.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 02/01/2021] [Accepted: 02/02/2021] [Indexed: 12/11/2022]
Abstract
The nucleolus functions as the cellular hub for the initiation and early steps of ribosome biogenesis. Ribosomes are key components of the translation machinery and, accordingly, their abundance needs to be adjusted to the cellular energy status. Further, to ensure translational fidelity, the integrity and quality of ribosomes needs to be monitored under conditions of cellular stress. Stressful insults, such as nutrient, genotoxic or proteotoxic stress, interfere with ribosome biogenesis and activate a cellular response referred to as nucleolar stress. This nucleolar stress response typically affects nucleolar integrity and is intricately linked to the activation of protein quality control pathways, including (i) the ubiquitin proteasome system (UPS) and (ii) the autophagy machinery, to restore cellular proteostasis. Here we will review some key features of the nucleolar stress response with a particular focus on the role of the UPS and autophagy in this process.
Collapse
Affiliation(s)
- Hannah Mende
- Institute of Biochemistry II, Goethe University, Medical School, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany
| | - Stefan Müller
- Institute of Biochemistry II, Goethe University, Medical School, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany.
| |
Collapse
|
8
|
Han XR, Sasaki N, Jackson SC, Wang P, Li Z, Smith MD, Xie L, Chen X, Zhang Y, Marzluff WF, Xiong Y. CRL4 DCAF1/VprBP E3 ubiquitin ligase controls ribosome biogenesis, cell proliferation, and development. SCIENCE ADVANCES 2020; 6:6/51/eabd6078. [PMID: 33355139 DOI: 10.1126/sciadv.abd6078] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 10/27/2020] [Indexed: 06/12/2023]
Abstract
Evolutionarily conserved DCAF1 is a major substrate receptor for the DDB1-CUL4-ROC1 E3 ubiquitin ligase (CRL4) and controls cell proliferation and development. The molecular basis for these functions is unclear. We show here that DCAF1 loss in multiple tissues and organs selectively eliminates proliferating cells and causes perinatal lethality, thymic atrophy, and bone marrow defect. Inducible DCAF1 loss eliminates proliferating, but not quiescent, T cells and MEFs. We identify the ribosome assembly factor PWP1 as a substrate of the CRL4DCAF1 ligase. DCAF1 loss results in PWP1 accumulation, impairing rRNA processing and ribosome biogenesis. Knockdown or overexpression of PWP1 can rescue defects or cause similar defects as DCAF1 loss, respectively, in ribosome biogenesis. DCAF1 loss increases free RPL11, resulting in L11-MDM2 association and p53 activation. Cumulatively, these results reveal a critical function for DCAF1 in ribosome biogenesis and define a molecular basis of DCAF1 function in cell proliferation and development.
Collapse
Affiliation(s)
- Xiao-Ran Han
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Naoya Sasaki
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Sarah C Jackson
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Pu Wang
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Zhijun Li
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Matthew D Smith
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Ling Xie
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Xian Chen
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Yanping Zhang
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Department of Radiation Oncology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - William F Marzluff
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Integrative Program for Biological and Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Yue Xiong
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Integrative Program for Biological and Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| |
Collapse
|
9
|
Costa RO, Martins H, Martins LF, Cwetsch AW, Mele M, Pedro JR, Tomé D, Jeon NL, Cancedda L, Jaffrey SR, Almeida RD. Synaptogenesis Stimulates a Proteasome-Mediated Ribosome Reduction in Axons. Cell Rep 2020; 28:864-876.e6. [PMID: 31340150 PMCID: PMC6686882 DOI: 10.1016/j.celrep.2019.06.080] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 12/21/2018] [Accepted: 06/21/2019] [Indexed: 11/19/2022] Open
Abstract
Ribosomes and a subset of cellular mRNAs are trafficked into axons of developing neurons. The axonal localization of translational machinery allows new proteins to be rapidly and locally synthesized during axonal growth and pathfinding. However, in mature neurons, axonal ribosomes are significantly reduced or even absent. The mechanism that elicits this removal is currently unknown. Here, we demonstrate that synapse formation is the trigger for ribosome reduction in mature axons. In vivo analysis shows that axonal ribosome levels decrease in rat brain at a developmental stage coincident with synapse formation. Next, we observe in vitro that different synaptogenic inducers trigger an overall decrease of ribosomal proteins and rRNA in the axons of spinal motor neurons. We further observe that this process is dependent on the ubiquitin-proteasome system but not on autophagy. Together, these data identify synaptogenesis as the long missing biological trigger that leads to ribosome disappearance during axonal maturation. The mechanism behind the striking loss of ribosomes from axons during neuronal maturation is unknown. Using in vivo and in vitro models, including neuron-muscle co-cultures and combining biochemistry and imaging techniques, Costa et al. demonstrate that synapse formation triggers ribosome reduction by a mechanism involving the ubiquitin-proteasome system.
Collapse
Affiliation(s)
- Rui O Costa
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal; Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal.
| | - Helena Martins
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal
| | - Luís F Martins
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal; Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal; PhD Programme in Experimental Biology and Biomedicine (PDBEB), Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Andrzej W Cwetsch
- NBT - Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, Genoa, Italy
| | - Miranda Mele
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal; Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal
| | - Joana R Pedro
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal
| | - Diogo Tomé
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal; iBiMED - Institute of Biomedicine, Department of Medical Sciences, University of Aveiro, Aveiro, Portugal
| | - Noo Li Jeon
- Institute of Advanced Machinery and Design, Seoul National University, Seoul, Republic of Korea; Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul, Republic of Korea
| | - Laura Cancedda
- NBT - Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, Genoa, Italy; Dulbecco Telethon Institute, Roma, Italy
| | - Samie R Jaffrey
- Department of Pharmacology, Weill Medical College of Cornell University, New York, NY 10065, USA
| | - Ramiro D Almeida
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal; Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal; iBiMED - Institute of Biomedicine, Department of Medical Sciences, University of Aveiro, Aveiro, Portugal.
| |
Collapse
|
10
|
Li S, Song X, Zhu W, Chen Y, Zhu R, Wang L, Chen X, Song J, Yang H. Light-Switchable Yolk-Mesoporous Shell UCNPs@MgSiO 3 for Nitric Oxide-Evoked Multidrug Resistance Reversal in Cancer Therapy. ACS APPLIED MATERIALS & INTERFACES 2020; 12:30066-30076. [PMID: 32393026 DOI: 10.1021/acsami.0c06102] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Gas therapy has emerged as a forceful strategy for augmenting the effects of chemotherapeutic drugs against cancer cells. However, it remains extremely challenging to effectively deliver gas into tissues of interest and unravel its underlying mechanisms. Herein, we designed a near-infrared (NIR) light-switchable nitric oxide (NO) delivery nanosystem for high-efficacy multidrug resistance (MDR) reversal in cancer therapy based on a yolk-shell upconverting nanoparticles@magnesium silica (UCNP@MgSiO3). The internal hollow cavity and flower-like mesoporous shell of UCNPs@MgSiO3 not only enabled a significantly high encapsulation capacity for the NO precursor (BNN6) and doxorubicin (DOX) but also allowed the enhanced cellular uptake, resulting in NIR-triggered NO generation and low pH-triggered DOX release in cancer cells. Mechanistically, intracellular NO can downregulate the drug efflux-related P-glycoprotein and adenosine 5'-triphosphate-binding cassette transporters, thereby increasing the DOX accumulation in the cell nuclei. Such combination therapy of NO and DOX induced the apoptosis of MDR cells and completely inhibited in vivo MDR tumor growth. We further elucidated the therapy mechanism via proteomic profiling, showcasing the downregulation of the ubiquitin-proteasome pathway and nuclear factor kappa-B signaling pathway in the NO-treated MDR cells. Therefore, our findings develop a promising nanoscale gas/drug delivery paradigm for fighting MDR tumors and providing molecular insights into cancer therapy.
Collapse
Affiliation(s)
- Shihua Li
- MOE Key Laboratory for Analytical Science of Food Safety and Biology, State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, China
| | - Xiaorong Song
- MOE Key Laboratory for Analytical Science of Food Safety and Biology, State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, China
| | - Wei Zhu
- MOE Key Laboratory for Analytical Science of Food Safety and Biology, State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, China
| | - Yongling Chen
- MOE Key Laboratory for Analytical Science of Food Safety and Biology, State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, China
| | - Rong Zhu
- MOE Key Laboratory for Analytical Science of Food Safety and Biology, State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, China
| | - Liping Wang
- MOE Key Laboratory for Analytical Science of Food Safety and Biology, State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, China
| | - Xian Chen
- MOE Key Laboratory for Analytical Science of Food Safety and Biology, State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, China
| | - Jibin Song
- MOE Key Laboratory for Analytical Science of Food Safety and Biology, State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, China
| | - Huanghao Yang
- MOE Key Laboratory for Analytical Science of Food Safety and Biology, State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, China
| |
Collapse
|
11
|
Dougherty SE, Maduka AO, Inada T, Silva GM. Expanding Role of Ubiquitin in Translational Control. Int J Mol Sci 2020; 21:E1151. [PMID: 32050486 PMCID: PMC7037965 DOI: 10.3390/ijms21031151] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Revised: 02/04/2020] [Accepted: 02/05/2020] [Indexed: 12/22/2022] Open
Abstract
The eukaryotic proteome has to be precisely regulated at multiple levels of gene expression, from transcription, translation, and degradation of RNA and protein to adjust to several cellular conditions. Particularly at the translational level, regulation is controlled by a variety of RNA binding proteins, translation and associated factors, numerous enzymes, and by post-translational modifications (PTM). Ubiquitination, a prominent PTM discovered as the signal for protein degradation, has newly emerged as a modulator of protein synthesis by controlling several processes in translation. Advances in proteomics and cryo-electron microscopy have identified ubiquitin modifications of several ribosomal proteins and provided numerous insights on how this modification affects ribosome structure and function. The variety of pathways and functions of translation controlled by ubiquitin are determined by the various enzymes involved in ubiquitin conjugation and removal, by the ubiquitin chain type used, by the target sites of ubiquitination, and by the physiologic signals triggering its accumulation. Current research is now elucidating multiple ubiquitin-mediated mechanisms of translational control, including ribosome biogenesis, ribosome degradation, ribosome-associated protein quality control (RQC), and redox control of translation by ubiquitin (RTU). This review discusses the central role of ubiquitin in modulating the dynamism of the cellular proteome and explores the molecular aspects responsible for the expanding puzzle of ubiquitin signals and functions in translation.
Collapse
Affiliation(s)
- Shannon E. Dougherty
- Department of Biology, Duke University, Durham, NC 27708-0338, USA; (S.E.D.); (A.O.M.)
| | - Austin O. Maduka
- Department of Biology, Duke University, Durham, NC 27708-0338, USA; (S.E.D.); (A.O.M.)
| | - Toshifumi Inada
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Japan;
| | - Gustavo M. Silva
- Department of Biology, Duke University, Durham, NC 27708-0338, USA; (S.E.D.); (A.O.M.)
| |
Collapse
|
12
|
Mishra R, Upadhyay A, Prajapati VK, Mishra A. Proteasome-mediated proteostasis: Novel medicinal and pharmacological strategies for diseases. Med Res Rev 2018; 38:1916-1973. [DOI: 10.1002/med.21502] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2017] [Revised: 03/13/2018] [Accepted: 04/04/2018] [Indexed: 02/06/2023]
Affiliation(s)
- Ribhav Mishra
- Cellular and Molecular Neurobiology Unit; Indian Institute of Technology Jodhpur; Rajasthan India
| | - Arun Upadhyay
- Cellular and Molecular Neurobiology Unit; Indian Institute of Technology Jodhpur; Rajasthan India
| | - Vijay Kumar Prajapati
- Department of Biochemistry; School of Life Sciences; Central University of Rajasthan; Rajasthan India
| | - Amit Mishra
- Cellular and Molecular Neurobiology Unit; Indian Institute of Technology Jodhpur; Rajasthan India
| |
Collapse
|
13
|
Montacié C, Durut N, Opsomer A, Palm D, Comella P, Picart C, Carpentier MC, Pontvianne F, Carapito C, Schleiff E, Sáez-Vásquez J. Nucleolar Proteome Analysis and Proteasomal Activity Assays Reveal a Link between Nucleolus and 26S Proteasome in A. thaliana. FRONTIERS IN PLANT SCIENCE 2017; 8:1815. [PMID: 29104584 PMCID: PMC5655116 DOI: 10.3389/fpls.2017.01815] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 10/06/2017] [Indexed: 05/23/2023]
Abstract
In all eukaryotic cells, the nucleolus is functionally and structurally linked to rRNA synthesis and ribosome biogenesis. This compartment contains as well factors involved in other cellular activities, but the functional interconnection between non-ribosomal activities and the nucleolus (structure and function) still remains an open question. Here, we report a novel mass spectrometry analysis of isolated nucleoli from Arabidopsis thaliana plants using the FANoS (Fluorescence Assisted Nucleolus Sorting) strategy. We identified many ribosome biogenesis factors (RBF) and proteins non-related with ribosome biogenesis, in agreement with the recognized multi-functionality of the nucleolus. Interestingly, we found that 26S proteasome subunits localize in the nucleolus and demonstrated that proteasome activity and nucleolus organization are intimately linked to each other. Proteasome subunits form discrete foci in the disorganized nucleolus of nuc1.2 plants. Nuc1.2 protein extracts display reduced proteasome activity in vitro compared to WT protein extracts. Remarkably, proteasome activity in nuc1.2 is similar to proteasome activity in WT plants treated with proteasome inhibitors (MG132 or ALLN). Finally, we show that MG132 treatment induces disruption of nucleolar structures in WT but not in nuc1.2 plants. Altogether, our data suggest a functional interconnection between nucleolus structure and proteasome activity.
Collapse
Affiliation(s)
- Charlotte Montacié
- Laboratoire Génome et Développement des Plantes, Centre National de la Recherche Scientifique, UMR 5096, Perpignan, France
- Laboratoire Génome et Développement des Plantes, University of Perpignan Via Domitia, UMR 5096, Perpignan, France
| | - Nathalie Durut
- Laboratoire Génome et Développement des Plantes, Centre National de la Recherche Scientifique, UMR 5096, Perpignan, France
- Laboratoire Génome et Développement des Plantes, University of Perpignan Via Domitia, UMR 5096, Perpignan, France
| | - Alison Opsomer
- Laboratoire de Spectrométrie de Masse BioOrganique, Institut Pluridisciplinaire Hubert Curien, UMR7178 Centre National de la Recherche Scientifique, Université de Strasbourg, Strasbourg, France
| | - Denise Palm
- Institute for Molecular Biosciences, Cluster of Excellence Macromolecular Complexes, Buchman Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt, Germany
| | - Pascale Comella
- Laboratoire Génome et Développement des Plantes, Centre National de la Recherche Scientifique, UMR 5096, Perpignan, France
- Laboratoire Génome et Développement des Plantes, University of Perpignan Via Domitia, UMR 5096, Perpignan, France
| | - Claire Picart
- Laboratoire Génome et Développement des Plantes, Centre National de la Recherche Scientifique, UMR 5096, Perpignan, France
- Laboratoire Génome et Développement des Plantes, University of Perpignan Via Domitia, UMR 5096, Perpignan, France
| | - Marie-Christine Carpentier
- Laboratoire Génome et Développement des Plantes, Centre National de la Recherche Scientifique, UMR 5096, Perpignan, France
- Laboratoire Génome et Développement des Plantes, University of Perpignan Via Domitia, UMR 5096, Perpignan, France
| | - Frederic Pontvianne
- Laboratoire Génome et Développement des Plantes, Centre National de la Recherche Scientifique, UMR 5096, Perpignan, France
- Laboratoire Génome et Développement des Plantes, University of Perpignan Via Domitia, UMR 5096, Perpignan, France
| | - Christine Carapito
- Laboratoire de Spectrométrie de Masse BioOrganique, Institut Pluridisciplinaire Hubert Curien, UMR7178 Centre National de la Recherche Scientifique, Université de Strasbourg, Strasbourg, France
| | - Enrico Schleiff
- Institute for Molecular Biosciences, Cluster of Excellence Macromolecular Complexes, Buchman Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt, Germany
| | - Julio Sáez-Vásquez
- Laboratoire Génome et Développement des Plantes, Centre National de la Recherche Scientifique, UMR 5096, Perpignan, France
- Laboratoire Génome et Développement des Plantes, University of Perpignan Via Domitia, UMR 5096, Perpignan, France
| |
Collapse
|
14
|
Korzhevskii DE, Gusel’nikova VV, Kirik OV, Sukhorukova EG, Grigorev IP. The Spatial Organization of the Intranuclear Structures of Human Brain Dopaminergic Neurons. Acta Naturae 2017; 9:81-88. [PMID: 29104779 PMCID: PMC5662277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Indexed: 10/24/2022] Open
Abstract
We studied the intranuclear localization of protein nucleophosmin (B23) and ubiquitin in the dopaminergic neurons of human substantia nigra (n = 6, age of 25-87 years) using immunohistochemistry and confocal laser microscopy. Intranuclear ubiquitin-immunopositive bodies that morphologically correspond to Marinesco bodies were found to be present in substantia nigra dopaminergic (tyrosine hydroxylase-immunopositive) neurons but absent in non-dopaminergic neurons. The number of bodies varied from 0 to 6 per cell nucleus. Nucleophosmin (B23) was found in the neuronal nucleolus, with the nucleolus size being constant in the nigral neurons of each individual brain. All the observed neurons had only one large nucleolus with intense nucleophosmin immunoreactivity and a lightly stained region (1-2 μm in diameter) that apparently represents the giant fibrillar center (GFC). An intensely immunostained nucleophosmin-containing granule was often observed at the GFC periphery. Double labeling demonstrated that nucleophosmin-immunoreactive nucleolus and ubiquitin-immunoreactive Marinesco bodies can occur both closely to and remotely from each other. Three-dimensional reconstruction indicates that rounded Marinesco bodies are polymorphic and often have a complex shape, with some flattening and concavities, which may be associated with contact not only with the nucleolus, but also, presumably, with other intranuclear structures free of ubiquitin or nucleophosmin. Ubiquitin-immunoreactive structures with a relatively small size (up to 1 μm in length) and various clastosome-like shapes (Lafarga et al., 2002) often occur near Marinesco bodies. There were no cases of detection of ubiquitin in the nucleoli of dopaminergic neurons and nucleophosmin/B23 in typical Marinesco bodies. The obtained information may be helpful in unraveling the molecular mechanisms of the selective vulnerability of substantia nigra dopaminergic neurons to damaging factors.
Collapse
Affiliation(s)
- D. E. Korzhevskii
- Federal State Budgetary Research Institution «Institute of Experimental Medicine», akad. Pavlov Str. 12, St. Petersburg, 197376, Russia
| | - V. V. Gusel’nikova
- Federal State Budgetary Research Institution «Institute of Experimental Medicine», akad. Pavlov Str. 12, St. Petersburg, 197376, Russia
| | - O. V. Kirik
- Federal State Budgetary Research Institution «Institute of Experimental Medicine», akad. Pavlov Str. 12, St. Petersburg, 197376, Russia
| | - E. G. Sukhorukova
- Federal State Budgetary Research Institution «Institute of Experimental Medicine», akad. Pavlov Str. 12, St. Petersburg, 197376, Russia
| | - I. P. Grigorev
- Federal State Budgetary Research Institution «Institute of Experimental Medicine», akad. Pavlov Str. 12, St. Petersburg, 197376, Russia
| |
Collapse
|
15
|
Xavier LADC, Bezerra JF, de Rezende AA, Oliveira RADC, Dalmolin RJS, do Amaral VS. Analysis of genome instability biomarkers in children with non-syndromic orofacial clefts. Mutagenesis 2017; 32:313-321. [DOI: 10.1093/mutage/gew068] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
|
16
|
Tsimokha AS, Zaykova JJ, Bottrill A, Barlev NA. Extracellular Proteasomes Are Deficient in 19S Subunits as Revealed by iTRAQ Quantitative Proteomics. J Cell Physiol 2016; 232:842-851. [DOI: 10.1002/jcp.25492] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2016] [Accepted: 07/18/2016] [Indexed: 12/31/2022]
Affiliation(s)
- Anna S. Tsimokha
- Institute of Cytology; Russian Academy of Sciences; St. Petersburg Russia
| | - Julia J. Zaykova
- Institute of Cytology; Russian Academy of Sciences; St. Petersburg Russia
| | - Andrew Bottrill
- Department of Biochemistry; University of Leicester; Leicester United Kingdom
| | - Nikolai A. Barlev
- Institute of Cytology; Russian Academy of Sciences; St. Petersburg Russia
| |
Collapse
|
17
|
Regulation of energy homeostasis by the ubiquitin-independent REGγ proteasome. Nat Commun 2016; 7:12497. [PMID: 27511885 PMCID: PMC4987533 DOI: 10.1038/ncomms12497] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 07/07/2016] [Indexed: 12/30/2022] Open
Abstract
Maintenance of energy homeostasis is essential for cell survival. Here, we report that the ATP- and ubiquitin-independent REGγ-proteasome system plays a role in maintaining energy homeostasis and cell survival during energy starvation via repressing rDNA transcription, a major intracellular energy-consuming process. Mechanistically, REGγ-proteasome limits cellular rDNA transcription and energy consumption by targeting the rDNA transcription activator SirT7 for ubiquitin-independent degradation under normal conditions. Moreover, energy starvation induces an AMPK-directed SirT7 phosphorylation and subsequent REGγ-dependent SirT7 subcellular redistribution and degradation, thereby further reducing rDNA transcription to save energy to overcome cell death. Energy starvation is a promising strategy for cancer therapy. Our report also shows that REGγ knockdown markedly improves the anti-tumour activity of energy metabolism inhibitors in mice. Our results underscore a control mechanism for an ubiquitin-independent process in maintaining energy homeostasis and cell viability under starvation conditions, suggesting that REGγ-proteasome inhibition has a potential to provide tumour-starving benefits. In conditions of energy stress cells reduce transcription of ribosomal RNA (rRNA) to maintain cell survival. Here, the authors show that energy stress induces an AMPK-dependent phosphorylation of Sirt7, which promotes its ubiquitin-independent degradation by REGγ, resulting in the down-regulation of rRNA transcription and cell survival.
Collapse
|
18
|
Badertscher L, Wild T, Montellese C, Alexander L, Bammert L, Sarazova M, Stebler M, Csucs G, Mayer T, Zamboni N, Zemp I, Horvath P, Kutay U. Genome-wide RNAi Screening Identifies Protein Modules Required for 40S Subunit Synthesis in Human Cells. Cell Rep 2015; 13:2879-91. [DOI: 10.1016/j.celrep.2015.11.061] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 10/11/2015] [Accepted: 11/18/2015] [Indexed: 02/08/2023] Open
|
19
|
N-Myristoylation of the Rpt2 subunit of the yeast 26S proteasome is implicated in the subcellular compartment-specific protein quality control system. J Proteomics 2015; 130:33-41. [PMID: 26344132 DOI: 10.1016/j.jprot.2015.08.021] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 08/14/2015] [Accepted: 08/27/2015] [Indexed: 12/14/2022]
Abstract
Ubiquitination is the posttranslational modification of a protein by covalent attachment of ubiquitin. Controlled proteolysis via the ubiquitin-proteasome system (\UPS) alleviates cellular stress by clearing misfolded proteins. In budding yeast, UPS within the nucleus degrades the nuclear proteins as well as proteins imported from the cytoplasm. While the predominantly nuclear localization of the yeast proteasome is maintained by the importin-mediated transport, N-myristoylation of the proteasome subunit Rpt2 was indicated to cause dynamic nucleo-cytoplasmic localization of proteasomes. Here, we quantitatively analyzed the ubiquitinated peptides using anti-K-ε-GG antibody in yeast cell lines with or without a mutation in the N-myristoylation site of Rpt2 and detected upregulated ubiquitination of proteins with nucleo-cytoplasmic localizations in the mutant strains. Moreover, both the protein and ubiquitinated peptide levels of two Hsp70 family chaperones involved in the nuclear import of misfolded proteins, Ssa and Sse1, were elevated in the mutant strains, whereas levels of an Hsp70 family chaperone involved in the nuclear export, Ssb, were reduced. Taken together, our results indicate that N-myristoylation of Rpt2 is involved in controlled proteolysis via regulation of the nucleo-cytoplasmic localization of the yeast proteasome.
Collapse
|
20
|
Chu XL, Feng MG, Ying SH. Qualitative ubiquitome unveils the potential significances of protein lysine ubiquitination in hyphal growth of Aspergillus nidulans. Curr Genet 2015; 62:191-201. [PMID: 26328806 DOI: 10.1007/s00294-015-0517-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Revised: 08/23/2015] [Accepted: 08/24/2015] [Indexed: 12/12/2022]
Abstract
Protein ubiquitination is an evolutionarily conserved post-translational modification process in eukaryotes, and it plays an important role in many biological processes. Aspergillus nidulans, a model filamentous fungus, contributes to our understanding of cellular physiology, metabolism and genetics, but its ubiquitination is not completely revealed. In this study, the ubiquitination sites in the proteome of A. nidulans were identified using a highly sensitive mass spectrometry combined with immuno-affinity enrichment of the ubiquitinated peptides. The 4816 ubiquitination sites were identified in 1913 ubiquitinated proteins, accounting for 18.1% of total proteins in A. nidulans. Bioinformatic analysis suggested that the ubiquitinated proteins associated with a number of biological functions and displayed various sub-cellular localisations. Meanwhile, seven motifs were revealed from the ubiquitinated peptides, and significantly over-presented in the different pathways. Comparison of the enriched functional catalogues indicated that the ubiquitination functions divergently during growth of A. nidulans and Saccharomyces cerevisiae. Additionally, the proteins in A. nidulans-specific sub-category (cell growth/morphogenesis) were subjected to the protein interaction analysis which demonstrated that ubiquitination is involved in the comprehensive protein interactions. This study presents a first proteomic view of ubiquitination in the filamentous fungus, and provides an initial framework for exploring the physiological roles of ubiquitination in A. nidulans.
Collapse
Affiliation(s)
- Xin-Ling Chu
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, People's Republic of China
| | - Ming-Guang Feng
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, People's Republic of China
| | - Sheng-Hua Ying
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, People's Republic of China.
| |
Collapse
|
21
|
Yoshikawa H, Ishikawa H, Izumikawa K, Miura Y, Hayano T, Isobe T, Simpson RJ, Takahashi N. Human nucleolar protein Nop52 (RRP1/NNP-1) is involved in site 2 cleavage in internal transcribed spacer 1 of pre-rRNAs at early stages of ribosome biogenesis. Nucleic Acids Res 2015; 43:5524-36. [PMID: 25969445 PMCID: PMC4477673 DOI: 10.1093/nar/gkv470] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 04/29/2015] [Indexed: 01/02/2023] Open
Abstract
During the early steps of ribosome biogenesis in mammals, the two ribosomal subunits 40S and 60S are produced via splitting of the large 90S pre-ribosomal particle (90S) into pre-40S and pre-60S pre-ribosomal particles (pre-40S and pre-60S). We previously proposed that replacement of fibrillarin by Nop52 (RRP1/NNP-1) for the binding to p32 (C1QBP) is a key event that drives this splitting process. However, how the replacement by RRP1 is coupled with the endo- and/or exo-ribonucleolytic cleavage of pre-rRNA remains unknown. In this study, we demonstrate that RRP1 deficiency suppressed site 2 cleavage on ITS1 of 47S/45S, 41S and 36S pre-rRNAs in human cells. RRP1 was also present in 90S and was localized in the dense fibrillar component of the nucleolus dependently on active RNA polymerase I transcription. In addition, double knockdown of XRN2 and RRP1 revealed that RRP1 accelerated the site 2 cleavage of 47S, 45S and 41S pre-rRNAs. These data suggest that RRP1 is involved not only in competitive binding with fibrillarin to C1QBP on 90S but also in site 2 cleavage in ITS1 of pre-rRNAs at early stages of human ribosome biogenesis; thus, it is likely that RRP1 integrates the cleavage of site 2 with the physical split of 90S into pre-40S and pre-60S.
Collapse
Affiliation(s)
- Harunori Yoshikawa
- Department of Applied Life Science, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo, 183-8509, Japan Centre for Gene Regulation & Expression, College of Life Sciences, University of Dundee, Dow Street, Dundee, DD1 5EH, UK
| | - Hideaki Ishikawa
- Department of Applied Life Science, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo, 183-8509, Japan Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Sanbancho 5, Chiyoda-ku, Tokyo, 102-0075, Japan
| | - Keiichi Izumikawa
- Department of Applied Life Science, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo, 183-8509, Japan Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Sanbancho 5, Chiyoda-ku, Tokyo, 102-0075, Japan
| | - Yutaka Miura
- Department of Applied Life Science, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo, 183-8509, Japan
| | - Toshiya Hayano
- Department of Applied Life Science, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo, 183-8509, Japan
| | - Toshiaki Isobe
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Sanbancho 5, Chiyoda-ku, Tokyo, 102-0075, Japan Department of Chemistry, Graduate School of Sciences and Engineering, Tokyo Metropolitan University, 1-1 Minamiosawa, Hachiouji-shi, Tokyo 192-0397, Japan
| | - Richard J Simpson
- La Trobe Institute for Molecular Science (LIMS), LIMS Building 1, Room 412 La Trobe University, Bundoora Victoria 3086, Australia
| | - Nobuhiro Takahashi
- Department of Applied Life Science, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo, 183-8509, Japan Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Sanbancho 5, Chiyoda-ku, Tokyo, 102-0075, Japan
| |
Collapse
|
22
|
A multiplexed, targeted mass spectrometry assay of the S100 protein family uncovers the isoform-specific expression in thyroid tumours. BMC Cancer 2015; 15:199. [PMID: 25880590 PMCID: PMC4391164 DOI: 10.1186/s12885-015-1217-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Accepted: 03/18/2015] [Indexed: 02/06/2023] Open
Abstract
Background Mounting evidence demonstrates a causal role for S100 proteins in tumourigenesis and several S100 isoforms have shown utility as biomarkers of several types of cancer. The S100 family is comprised of 21 small isoforms, many of them implicated in important cellular functions such as proliferation, motility and survival. Furthermore, in vivo experiments have proven the role of S100 proteins in tumour growth and disease progression, while other studies have shown their prognostic value and involvement in resistance to chemotherapy drugs. Taken together, all these aspects highlight S100 proteins as potential therapeutic targets and as a promising panel of cancer biomarkers. In this work, we have developed a mass spectrometry (MS)-based method for the multiplexed and specific analysis of the entire S100 protein family in tumour tissues and have applied it to investigate the expression of S100 isoforms in the context of thyroid cancer, the main endocrine malignancy. Methods Selected Reaction Monitoring (SRM)-MS and stable isotope labelling/label-free analysis were employed to investigate the expression of the 21 S100 protein isoforms in thyroid tissue samples. Specimens included 9 normal thyroid tissues and 27 tumour tissues consisting of 9 follicular adenomas (FA), 8 follicular carcinomas (FTC) and 10 papillary carcinomas (PTC). Results The multiplexed and targeted mass spectrometry method led to the detection of eleven S100 protein isoforms across all tissues. Label- and label-free analyses showed the same significant differences and results were confirmed by western blot. S100A6, S100A11 and its putative interaction partner annexin A1 showed the highest overexpression in PTC compared to normal thyroid. S100A13 was also elevated in PTC. Reduced S100A4 expression was observed in FA compared to all other tissues. FA and FTC showed reduction of S100A10 and annexin A2 expression. Conclusions Targeted mass spectrometry allows the multiplexed and specific analysis of S100 protein isoforms in tumour tissue specimens. It revealed S100A13 as a novel candidate PTC biomarker. Results show that S100A6, S100A11 and Annexin A1 could help discriminate follicular and papillary tumours. The diagnostic and functional significance of S100A4 and S100A10 reduction in follicular tumours requires further investigation. Electronic supplementary material The online version of this article (doi:10.1186/s12885-015-1217-x) contains supplementary material, which is available to authorized users.
Collapse
|
23
|
Latonen L. Protein aggregation in neurodegenerative disease: the nucleolar connection. AIMS MOLECULAR SCIENCE 2015. [DOI: 10.3934/molsci.2015.3.324] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
|
24
|
Kakihara Y, Makhnevych T, Zhao L, Tang W, Houry WA. Nutritional status modulates box C/D snoRNP biogenesis by regulated subcellular relocalization of the R2TP complex. Genome Biol 2014; 15:404. [PMID: 25060708 PMCID: PMC4165372 DOI: 10.1186/s13059-014-0404-4] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Accepted: 07/07/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Box C/D snoRNPs, which are typically composed of box C/D snoRNA and the four core protein components Nop1, Nop56, Nop58, and Snu13, play an essential role in the modification and processing of pre-ribosomal RNA. The highly conserved R2TP complex, comprising the proteins Rvb1, Rvb2, Tah1, and Pih1, has been shown to be required for box C/D snoRNP biogenesis and assembly; however, the molecular basis of R2TP chaperone-like activity is not yet known. RESULTS Here, we describe an unexpected finding in which the activity of the R2TP complex is required for Nop58 protein stability and is controlled by the dynamic subcellular redistribution of the complex in response to growth conditions and nutrient availability. In growing cells, the complex localizes to the nucleus and interacts with box C/D snoRNPs. This interaction is significantly reduced in poorly growing cells as R2TP predominantly relocalizes to the cytoplasm. The R2TP-snoRNP interaction is mainly mediated by Pih1. CONCLUSIONS The R2TP complex exerts a novel regulation on box C/D snoRNP biogenesis that affects their assembly and consequently pre-rRNA maturation in response to different growth conditions.
Collapse
|
25
|
Sangith N, Srinivasaraghavan K, Sahu I, Desai A, Medipally S, Somavarappu AK, Verma C, Venkatraman P. Discovery of novel interacting partners of PSMD9, a proteasomal chaperone: Role of an Atypical and versatile PDZ-domain motif interaction and identification of putative functional modules. FEBS Open Bio 2014; 4:571-83. [PMID: 25009770 PMCID: PMC4087146 DOI: 10.1016/j.fob.2014.05.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 05/20/2014] [Accepted: 05/24/2014] [Indexed: 12/21/2022] Open
Abstract
The structure and functions of PSMD9, a proteasomal chaperone, are uncharacterized. PDZ-like domain of PSMD9 may recognize C-terminal residues in proteins. Using conserved C-terminal motifs in human proteome, we identify novel binding partners. hnRNPA1, GH, IL6-receptor, S14 and E12 interact with PSMD9 via a specific C-terminal motif. We predict and confirm residues in the PDZ domain that are involved in this interaction.
PSMD9 (Proteasome Macropain non-ATPase subunit 9), a proteasomal assembly chaperone, harbors an uncharacterized PDZ-like domain. Here we report the identification of five novel interacting partners of PSMD9 and provide the first glimpse at the structure of the PDZ-domain, including the molecular details of the interaction. We based our strategy on two propositions: (a) proteins with conserved C-termini may share common functions and (b) PDZ domains interact with C-terminal residues of proteins. Screening of C-terminal peptides followed by interactions using full-length recombinant proteins, we discovered hnRNPA1 (an RNA binding protein), S14 (a ribosomal protein), CSH1 (a growth hormone), E12 (a transcription factor) and IL6 receptor as novel PSMD9-interacting partners. Through multiple techniques and structural insights, we clearly demonstrate for the first time that human PDZ domain interacts with the predicted Short Linear Sequence Motif (SLIM) at the C-termini of the client proteins. These interactions are also recapitulated in mammalian cells. Together, these results are suggestive of the role of PSMD9 in transcriptional regulation, mRNA processing and editing, hormone and receptor activity and protein translation. Our proof-of-principle experiments endorse a novel and quick method for the identification of putative interacting partners of similar PDZ-domain proteins from the proteome and for discovering novel functions.
Collapse
Affiliation(s)
- Nikhil Sangith
- Advanced Centre for Treatment, Research and Education in Cancer (ACTREC), Tata Memorial Centre (TMC), Kharghar, Navi Mumbai 410210, India
| | - Kannan Srinivasaraghavan
- Bioinformatics Institute ASTAR, 30 Biopolis Street, #07-01 Matrix, Singapore 138671, Singapore ; Experimental Therapeutics Centre (A*STAR), 31 Biopolis Street, #03-01 Helios, Singapore 138669, Singapore
| | - Indrajit Sahu
- Advanced Centre for Treatment, Research and Education in Cancer (ACTREC), Tata Memorial Centre (TMC), Kharghar, Navi Mumbai 410210, India
| | - Ankita Desai
- Advanced Centre for Treatment, Research and Education in Cancer (ACTREC), Tata Memorial Centre (TMC), Kharghar, Navi Mumbai 410210, India
| | - Spandana Medipally
- Advanced Centre for Treatment, Research and Education in Cancer (ACTREC), Tata Memorial Centre (TMC), Kharghar, Navi Mumbai 410210, India
| | - Arun Kumar Somavarappu
- Advanced Centre for Treatment, Research and Education in Cancer (ACTREC), Tata Memorial Centre (TMC), Kharghar, Navi Mumbai 410210, India
| | - Chandra Verma
- Bioinformatics Institute ASTAR, 30 Biopolis Street, #07-01 Matrix, Singapore 138671, Singapore ; School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore ; Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore
| | - Prasanna Venkatraman
- Advanced Centre for Treatment, Research and Education in Cancer (ACTREC), Tata Memorial Centre (TMC), Kharghar, Navi Mumbai 410210, India
| |
Collapse
|
26
|
Cacciapuoti F. Role of ubiquitin-proteasome system (UPS) in left ventricular hypertrophy (LVH). AMERICAN JOURNAL OF CARDIOVASCULAR DISEASE 2014; 4:1-5. [PMID: 24551479 PMCID: PMC3925880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/29/2013] [Accepted: 01/05/2014] [Indexed: 06/03/2023]
Abstract
Cardiac hypertrophy is a key compensatory mechanism acting in response to pressure or volume overload, involving some alterations in signaling transduction pathways and transcription factors-regulation. These changes result in enhanced proteins' synthesis leading to Left Ventricular Hypertrophy (LVH). It is known that the main function of Ubiquitin-Proteasome System (UPS) is to prevent accumulation of damaged, misfolded and mutant proteins by proteolysis. But emerging evidences suggest that UPS also attends to the cells' growth, favoring proteins' synthesis, subsequently evolving in LVH. The role of the proteasome in to favor cellular hypertrophy consists in upregulation of the catalytic proteasome subunit, with prevalence of proteins-synthesis on proteins degradation. It is also evident that UPS inhibition may prevent cells' growth opposing to the hypertrophy. In fact in several experimental models, UPS inhibition demonstrated to be able to prevent or reverse cardiac hypertrophy induced by abdominal aortic banding (AAB). That can happen with several proteasome inhibitors acting by multifactorial mechanisms. These evidences induce to hypothesize that, in the future, in patients with the increased volume overload by systemic hypertension, some proteasome-inhibitors could be used to antagonize or prevent LVH without reducing peripheral high blood pressure levels too.
Collapse
|
27
|
Palanca A, Casafont I, Berciano MT, Lafarga M. Reactive nucleolar and Cajal body responses to proteasome inhibition in sensory ganglion neurons. Biochim Biophys Acta Mol Basis Dis 2013; 1842:848-59. [PMID: 24269586 DOI: 10.1016/j.bbadis.2013.11.016] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Revised: 11/12/2013] [Accepted: 11/13/2013] [Indexed: 12/25/2022]
Abstract
The dysfunction of the ubiquitin proteasome system has been related to a broad array of neurodegenerative disorders in which the accumulation of misfolded protein aggregates causes proteotoxicity. The ability of proteasome inhibitors to induce cell cycle arrest and apoptosis has emerged as a powerful strategy for cancer therapy. Bortezomib is a proteasome inhibitor used as an antineoplastic drug, although its neurotoxicity frequently causes a severe sensory peripheral neuropathy. In this study we used a rat model of bortezomib treatment to study the nucleolar and Cajal body responses to the proteasome inhibition in sensory ganglion neurons that are major targets of bortezomib-induced neurotoxicity. Treatment with bortezomib induced dose-dependent dissociation of protein synthesis machinery (chromatolysis) and nuclear retention of poly(A) RNA granules resulting in neuronal dysfunction. However, as a compensatory response to the proteotoxic stress, both nucleoli and Cajal bodies exhibited reactive changes. These include an increase in the number and size of nucleoli, strong nucleolar incorporation of the RNA precursor 5'-fluorouridine, and increased expression of both 45S rRNA and genes encoding nucleolar proteins UBF, fibrillarin and B23. Taken together, these findings appear to reflect the activation of the nucleolar transcription in response to proteotoxic stress Furthermore, the number of Cajal bodies, a parameter related to transcriptional activity, increases upon proteasome inhibition. We propose that nucleoli and Cajal bodies are important targets in the signaling pathways that are activated by the proteotoxic stress response to proteasome inhibition. The coordinating activity of these two organelles in the production of snRNA, snoRNA and rRNA may contribute to neuronal survival after proteasome inhibition. This article is part of a Special Issue entitled: Role of the Nucleolus in Human Disease.
Collapse
Affiliation(s)
- Ana Palanca
- Department of Anatomy and Cell Biology, University of Cantabria-IFIMAV, Santander, Spain; "Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED)", Santander, Spain
| | - Iñigo Casafont
- Department of Anatomy and Cell Biology, University of Cantabria-IFIMAV, Santander, Spain; "Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED)", Santander, Spain
| | - María T Berciano
- Department of Anatomy and Cell Biology, University of Cantabria-IFIMAV, Santander, Spain; "Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED)", Santander, Spain
| | - Miguel Lafarga
- Department of Anatomy and Cell Biology, University of Cantabria-IFIMAV, Santander, Spain; "Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED)", Santander, Spain.
| |
Collapse
|
28
|
Dasuri K, Zhang L, Keller JN. Oxidative stress, neurodegeneration, and the balance of protein degradation and protein synthesis. Free Radic Biol Med 2013; 62:170-185. [PMID: 23000246 DOI: 10.1016/j.freeradbiomed.2012.09.016] [Citation(s) in RCA: 256] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Revised: 09/05/2012] [Accepted: 09/11/2012] [Indexed: 12/12/2022]
Abstract
Oxidative stress occurs in a variety of disease settings and is strongly linked to the development of neuron death and neuronal dysfunction. Cells are equipped with numerous pathways to prevent the genesis, as well as the consequences, of oxidative stress in the brain. In this review we discuss the various forms and sources of oxidative stress in the brain and briefly discuss some of the complexities in detecting the presence of oxidative stress. We then focus the review on the interplay between the diverse cellular proteolytic pathways and their roles in regulating oxidative stress in the brain. Additionally, we discuss the involvement of protein synthesis in regulating the downstream effects of oxidative stress. Together, these components of the review demonstrate that the removal of damaged proteins by effective proteolysis and the synthesis of new and protective proteins are vital in the preservation of brain homeostasis during periods of increased levels of reactive oxygen species. Last, studies from our laboratory and others have demonstrated that protein synthesis is intricately linked to the rates of protein degradation, with impairment of protein degradation sufficient to decrease the rates of protein synthesis, which has important implications for successfully responding to periods of oxidative stress. Specific neurodegenerative diseases, including Alzheimer disease, Parkinson disease, amyotrophic lateral sclerosis, and stroke, are discussed in this context. Taken together, these findings add to our understanding of how oxidative stress is effectively managed in the healthy brain and help elucidate how impairments in proteolysis and/or protein synthesis contribute to the development of neurodegeneration and neuronal dysfunction in a variety of clinical settings.
Collapse
Affiliation(s)
- Kalavathi Dasuri
- Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA
| | - Le Zhang
- Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA
| | - Jeffrey N Keller
- Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA.
| |
Collapse
|
29
|
Proteasome activity influences UV-mediated subnuclear localization changes of NPM. PLoS One 2013; 8:e59096. [PMID: 23554979 PMCID: PMC3595268 DOI: 10.1371/journal.pone.0059096] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Accepted: 02/12/2013] [Indexed: 01/08/2023] Open
Abstract
UV damage activates cellular stress signaling pathways, causes DNA helix distortions and inhibits transcription by RNA polymerases I and II. In particular, the nucleolus, which is the site of RNA polymerase I transcription and ribosome biogenesis, disintegrates following UV damage. The disintegration is characterized by reorganization of the subnucleolar structures and change of localization of many nucleolar proteins. Here we have queried the basis of localization change of nucleophosmin (NPM), a nucleolar granular component protein, which is increasingly detected in the nucleoplasm following UV radiation. Using photobleaching experiments of NPM-fluorescent fusion protein in live human cells we show that NPM mobility increases after UV damage. However, we show that the increase in NPM nucleoplasmic abundance after UV is independent of UV-activated cellular stress and DNA damage signaling pathways. Unexpectedly, we find that proteasome activity affects NPM redistribution. NPM nucleolar expression was maintained when the UV-treated cells were exposed to proteasome inhibitors or when the expression of proteasome subunits was inhibited using RNAi. However, there was no evidence of increased NPM turnover in the UV damaged cells, or that ubiquitin or ubiquitin recycling affected NPM localization. These findings suggest that proteasome activity couples to nucleolar protein localizations in UV damage stress.
Collapse
|
30
|
Reading BJ, Williams VN, Chapman RW, Williams TI, Sullivan CV. Dynamics of the striped bass (Morone saxatilis) ovary proteome reveal a complex network of the translasome. J Proteome Res 2013; 12:1691-9. [PMID: 23414552 DOI: 10.1021/pr3010293] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We evaluated changes in the striped bass (Morone saxatilis) ovary proteome during the annual reproductive cycle using label-free quantitative mass spectrometry and a novel machine learning analysis based on K-means clustering and support vector machines. Modulated modularity clustering was used to group co-variable proteins into expression modules and Gene Ontology (GO) biological process and KEGG pathway enrichment analyses were conducted for proteins within those modules. We discovered that components of the ribosome along with translation initiation and elongation factors generally decrease as the annual ovarian cycle progresses toward ovulation, concomitant with a slight increase in components of the 26S-proteasome. Co-variation within more than one expression module of components from these two multi-protein complexes suggests that they are not only co-regulated, but that co-regulation occurs through more than one sub-network. These components also co-vary with subunits of the TCP-1 chaperonin system and enzymes of intermediary metabolic pathways, suggesting that protein folding and cellular bioenergetic state play important roles in protein synthesis and degradation. We provide further evidence to suggest that protein synthesis and degradation are intimately linked, and our results support function of a proteasome-ribosome supercomplex known as the translasome.
Collapse
Affiliation(s)
- Benjamin J Reading
- Department of Biology and §Mass Spectrometry Facility, Department of Chemistry, North Carolina State University , Raleigh, North Carolina, United States
| | | | | | | | | |
Collapse
|
31
|
Carroll AJ. The Arabidopsis Cytosolic Ribosomal Proteome: From form to Function. FRONTIERS IN PLANT SCIENCE 2013; 4:32. [PMID: 23459595 PMCID: PMC3585428 DOI: 10.3389/fpls.2013.00032] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Accepted: 02/10/2013] [Indexed: 05/20/2023]
Abstract
The cytosolic ribosomal proteome of Arabidopsis thaliana has been studied intensively by a range of proteomics approaches and is now one of the most well characterized eukaryotic ribosomal proteomes. Plant cytosolic ribosomes are distinguished from other eukaryotic ribosomes by unique proteins, unique post-translational modifications and an abundance of ribosomal proteins for which multiple divergent paralogs are expressed and incorporated. Study of the A. thaliana ribosome has now progressed well beyond a simple cataloging of protein parts and is focused strongly on elucidating the functions of specific ribosomal proteins, their paralogous isoforms and covalent modifications. This review summarises current knowledge concerning the Arabidopsis cytosolic ribosomal proteome and highlights potentially fruitful areas of future research in this fast moving and important area.
Collapse
Affiliation(s)
- Adam J. Carroll
- Australian Research Council Centre of Excellence in Plant Energy Biology, Australian National UniversityCanberra, ACT, Australia
- *Correspondence: Adam J. Carroll, Australian Research Council Centre of Excellence in Plant Energy Biology, Australian National University, ACT 0200, Canberra, Australia. e-mail:
| |
Collapse
|
32
|
Nabavi N, Pustylnik S, Harrison RE. Rab GTPase mediated procollagen trafficking in ascorbic acid stimulated osteoblasts. PLoS One 2012; 7:e46265. [PMID: 23050002 PMCID: PMC3458846 DOI: 10.1371/journal.pone.0046265] [Citation(s) in RCA: 18] [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: 05/01/2012] [Accepted: 08/30/2012] [Indexed: 12/24/2022] Open
Abstract
Despite advances in investigating functional aspects of osteoblast (OB) differentiation, especially studies on how bone proteins are deposited and mineralized, there has been little research on the intracellular trafficking of bone proteins during OB differentiation. Collagen synthesis and secretion is the major function of OBs and is markedly up-regulated upon ascorbic acid (AA) stimulation, significantly more so than in fibroblast cells. Understanding the mechanism by which collagen is mobilized in specialized OB cells is important for both basic cell biology and diseases involving defects in bone protein secretion and deposition. Protein trafficking along the exocytic and endocytic pathways is aided by many molecules, with Rab GTPases being master regulators of vesicle targeting. In this study, we used microarray analysis to identify the Rab GTPases that are up-regulated during a 5-day AA differentiation of OBs, namely Rab1, Rab3d, and Rab27b. Further, we investigated the role of identified Rabs in regulating the trafficking of collagen from the site of synthesis in the ER to the Golgi and ultimately to the plasma membrane utilizing Rab dominant negative (DN) expression. We also observed that experimental halting of biosynthetic trafficking by these mutant Rabs initiated proteasome-mediated degradation of procollagen and ceased global protein translation. Acute expression of Rab1 and Rab3d DN constructs partially alleviated this negative feedback mechanism and resulted in impaired ER to Golgi trafficking of procollagen. Similar expression of Rab27b DN constructs resulted in dispersed collagen vesicles which may represent failed secretory vesicles sequestered in the cytosol. A significant and strong reduction in extracellular collagen levels was also observed implicating the functional importance of Rab1, Rab3d and Rab27b in these major collagen-producing cells.
Collapse
Affiliation(s)
- Noushin Nabavi
- Department of Cell and Systems Biology, University of Tronto Scarborought, Toronto, Ontario, Canada
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
| | - Sofia Pustylnik
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
| | - Rene E. Harrison
- Department of Cell and Systems Biology, University of Tronto Scarborought, Toronto, Ontario, Canada
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
- * E-mail:
| |
Collapse
|
33
|
Richardson LA, Reed BJ, Charette JM, Freed EF, Fredrickson EK, Locke MN, Baserga SJ, Gardner RG. A conserved deubiquitinating enzyme controls cell growth by regulating RNA polymerase I stability. Cell Rep 2012; 2:372-85. [PMID: 22902402 DOI: 10.1016/j.celrep.2012.07.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2012] [Revised: 06/11/2012] [Accepted: 07/25/2012] [Indexed: 12/22/2022] Open
Abstract
Eukaryotic ribosome biogenesis requires hundreds of trans-acting factors and dozens of RNAs. Although most factors required for ribosome biogenesis have been identified, little is known about their regulation. Here, we reveal that the yeast deubiquitinating enzyme Ubp10 is localized to the nucleolus and that ubp10Δ cells have reduced pre-rRNAs, mature rRNAs, and translating ribosomes. Through proteomic analyses, we found that Ubp10 interacts with proteins that function in rRNA production and ribosome biogenesis. In particular, we discovered that the largest subunit of RNA polymerase I (RNAPI) is stabilized via Ubp10-mediated deubiquitination and that this is required in order to achieve optimal levels of ribosomes and cell growth. USP36, the human ortholog of Ubp10, complements the ubp10Δ allele for RNAPI stability, pre-rRNA processing, and cell growth in yeast, suggesting that deubiquitination of RNAPI may be conserved in eukaryotes. Our work implicates Ubp10/USP36 as a key regulator of rRNA production through control of RNAPI stability.
Collapse
|
34
|
Stępiński D. Immunofluorescent localization of ubiquitin and proteasomes in nucleolar vacuoles of soybean root meristematic cells. Eur J Histochem 2012; 56:e13. [PMID: 22688294 PMCID: PMC3428962 DOI: 10.4081/ejh.2012.e13] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
In this study, using the immunofluorescent method, the immunopositive signals to ubiquitin and proteasomes in nucleoli of root meristematic cells of soybean seedlings have been observed. In fact, those signals were present exclusively in nucleolar vacuoles. No signals were observed in the nucleolar territory out of the nucleolar vacuoles or in the nucleoli without vacuoles. The ubiquitin-proteasome system (UPS) may act within the nucleoli of plants with high metabolic activities and may provide an additional level of regulation of intracellular proteolysis via compartment-specific activities of their components. It is suggested that the presence of the UPS solely in vacuolated nucleoli serves as a mechanism that enhances the speed of ribosome subunit production in very actively transcribing nucleoli. On the other hand, nucleolar vacuoles in a cell/nucleus could play additional roles associated with temporary sequestration or storage of some cellular factors, including components of the ubiquitin-proteasome system.
Collapse
|
35
|
Stępiński D. Immunofluorescent localization of ubiquitin and proteasomes in nucleolar vacuoles of soybean root meristematic cells. Eur J Histochem 2012; 56:e13. [PMID: 22688294 PMCID: PMC3428962 DOI: 10.4081/ejh.2012.13] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Revised: 01/27/2012] [Accepted: 01/27/2012] [Indexed: 01/01/2023] Open
Abstract
In this study, using the immunofluorescent method, the immunopositive signals to ubiquitin and proteasomes in nucleoli of root meristematic cells of soybean seedlings have been observed. In fact, those signals were present exclusively in nucleolar vacuoles. No signals were observed in the nucleolar territory out of the nucleolar vacuoles or in the nucleoli without vacuoles. The ubiquitin-proteasome system (UPS) may act within the nucleoli of plants with high metabolic activities and may provide an additional level of regulation of intracellular proteolysis via compartment-specific activities of their components. It is suggested that the presence of the UPS solely in vacuolated nucleoli serves as a mechanism that enhances the speed of ribosome subunit production in very actively transcribing nucleoli. On the other hand, nucleolar vacuoles in a cell/nucleus could play additional roles associated with temporary sequestration or storage of some cellular factors, including components of the ubiquitin-proteasome system.
Collapse
Affiliation(s)
- D Stępiński
- Department of Cytophysiology, University of Łódź, Poland.
| |
Collapse
|
36
|
Vilotti S, Codrich M, Dal Ferro M, Pinto M, Ferrer I, Collavin L, Gustincich S, Zucchelli S. Parkinson's disease DJ-1 L166P alters rRNA biogenesis by exclusion of TTRAP from the nucleolus and sequestration into cytoplasmic aggregates via TRAF6. PLoS One 2012; 7:e35051. [PMID: 22532838 PMCID: PMC3332112 DOI: 10.1371/journal.pone.0035051] [Citation(s) in RCA: 45] [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: 11/16/2011] [Accepted: 03/08/2012] [Indexed: 01/21/2023] Open
Abstract
Mutations in PARK7/DJ-1 gene are associated to autosomal recessive early onset forms of Parkinson's disease (PD). Although large gene deletions have been linked to a loss-of-function phenotype, the pathogenic mechanism of missense mutations is less clear. The L166P mutation causes misfolding of DJ-1 protein and its degradation. L166P protein may also accumulate into insoluble cytoplasmic aggregates with a mechanism facilitated by the E3 ligase TNF receptor associated factor 6 (TRAF6). Upon proteasome impairment L166P activates the JNK/p38 MAPK apoptotic pathway by its interaction with TRAF and TNF Receptor Associated Protein (TTRAP). When proteasome activity is blocked in the presence of wild-type DJ-1, TTRAP forms aggregates that are localized to the cytoplasm or associated to nucleolar cavities, where it is required for a correct rRNA biogenesis. In this study we show that in post-mortem brains of sporadic PD patients TTRAP is associated to the nucleolus and to Lewy Bodies, cytoplasmic aggregates considered the hallmark of the disease. In SH-SY5Y neuroblastoma cells, misfolded mutant DJ-1 L166P alters rRNA biogenesis inhibiting TTRAP localization to the nucleolus and enhancing its recruitment into cytoplasmic aggregates with a mechanism that depends in part on TRAF6 activity. This work suggests that TTRAP plays a role in the molecular mechanisms of both sporadic and familial PD. Furthermore, it unveils the existence of an interplay between cytoplasmic and nucleolar aggregates that impacts rRNA biogenesis and involves TRAF6.
Collapse
Affiliation(s)
| | | | - Marco Dal Ferro
- Laboratorio Nazionale Consorzio Interuniversitario Biotecnologie, Trieste, Italy
- Department of Life Sciences (DSV), University of Trieste, Trieste, Italy
| | | | - Isidro Ferrer
- Institute of Neuropathology, Institut d'Investigacio Biomedica de Bellvitge, University Hospital Bellvitge, University of Barcellona, Llbregat, Spain
- SISSA Unit, Italian Institute of Technology (IIT), Trieste, Italy
| | - Licio Collavin
- Laboratorio Nazionale Consorzio Interuniversitario Biotecnologie, Trieste, Italy
- Department of Life Sciences (DSV), University of Trieste, Trieste, Italy
| | - Stefano Gustincich
- SISSA, Sector of Neurobiology, Trieste, Italy
- Institute of Neuropathology, Institut d'Investigacio Biomedica de Bellvitge, University Hospital Bellvitge, University of Barcellona, Llbregat, Spain
- SISSA Unit, Italian Institute of Technology (IIT), Trieste, Italy
- * E-mail: (SG); (SZ)
| | - Silvia Zucchelli
- SISSA, Sector of Neurobiology, Trieste, Italy
- Institute of Neuropathology, Institut d'Investigacio Biomedica de Bellvitge, University Hospital Bellvitge, University of Barcellona, Llbregat, Spain
- SISSA Unit, Italian Institute of Technology (IIT), Trieste, Italy
- * E-mail: (SG); (SZ)
| |
Collapse
|
37
|
40S subunit dissociation and proteasome-dependent RNA degradation in nonfunctional 25S rRNA decay. EMBO J 2012; 31:2579-89. [PMID: 22505030 DOI: 10.1038/emboj.2012.85] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2011] [Accepted: 03/15/2012] [Indexed: 11/08/2022] Open
Abstract
Eukaryotic cells have quality control systems that eliminate nonfunctional rRNAs with deleterious mutations (nonfunctional rRNA decay, NRD). We have previously reported that 25S NRD requires an E3 ubiquitin ligase complex, which is involved in ribosomal ubiquitination. However, the degradation process of nonfunctional ribosomes has remained unknown. Here, using genetic screening, we identified two ubiquitin-binding complexes, the Cdc48-Npl4-Ufd1 complex (Cdc48 complex) and the proteasome, as the factors involved in 25S NRD. We show that the nonfunctional 60S subunit is dissociated from the 40S subunit in a Cdc48 complex-dependent manner, before it is attacked by the proteasome. When we examined the nonfunctional 60S subunits that accumulated under proteasome-depleted conditions, the majority of mutant 25S rRNAs retained their full length at a single-nucleotide resolution. This indicates that the proteasome is an essential factor triggering rRNA degradation. We further showed that ribosomal ubiquitination can be stimulated solely by the suppression of the proteasome, suggesting that ubiquitin-proteasome-dependent RNA degradation occurs in broader situations, including in general rRNA turnover.
Collapse
|
38
|
Boyd MT, Vlatkovic N, Rubbi CP. The nucleolus directly regulates p53 export and degradation. ACTA ACUST UNITED AC 2012; 194:689-703. [PMID: 21893597 PMCID: PMC3171122 DOI: 10.1083/jcb.201105143] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Nucleoli directly regulate p53 export and degradation rather than simply sequestering p53 regulatory factors. The correlation between stress-induced nucleolar disruption and abrogation of p53 degradation is evident after a wide variety of cellular stresses. This link may be caused by steps in p53 regulation occurring in nucleoli, as suggested by some biochemical evidence. Alternatively, nucleolar disruption also causes redistribution of nucleolar proteins, potentially altering their interactions with p53 and/or MDM2. This raises the fundamental question of whether the nucleolus controls p53 directly, i.e., as a site where p53 regulatory processes occur, or indirectly, i.e., by determining the cellular localization of p53/MDM2-interacting factors. In this work, transport experiments based on heterokaryons, photobleaching, and micronucleation demonstrate that p53 regulatory events are directly regulated by nucleoli and are dependent on intact nucleolar structure and function. Subcellular fractionation and nucleolar isolation revealed a distribution of ubiquitylated p53 that supports these findings. In addition, our results indicate that p53 is exported by two pathways: one stress sensitive and one stress insensitive, the latter being regulated by activities present in the nucleolus.
Collapse
Affiliation(s)
- Mark T Boyd
- p53/MDM2 Research Group, Department of Molecular and Clinical Cancer Medicine, University of Liverpool, Liverpool L69 3GA, England, UK
| | | | | |
Collapse
|
39
|
Panasenko OO, Collart MA. Presence of Not5 and ubiquitinated Rps7A in polysome fractions depends upon the Not4 E3 ligase. Mol Microbiol 2012; 83:640-53. [PMID: 22243599 DOI: 10.1111/j.1365-2958.2011.07957.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
In this study, we determine that Saccharomyces cerevisiae Not4 E3 ligase ubiquitinates Rps7A in vivo and in vitro, but not its paralogue, Rps7B. Ubiquitinated Rps7A is detectable only in 80S and polysomes, but not in free 40S fractions. A different role of the Rps7 paralogues in vivo is supported by the observation that the deletion of Rps7A but not Rps7B is sensitive to translational inhibitors and leads to an accumulation of aggregated proteins. An important accumulation of aggregated proteins that include ribosomal proteins and ribosome-associated chaperones is also observed in cells lacking Not4. A contribution of Not4 to ribosomal function extending beyond Rps7A ubiquitination is supported by the observation that the deletion of Not4 displays a synthetic slow growth phenotype when combined with the deletion of either one of the two Rps7 paralogues. Not4 is detectable in polysome fractions, as are other subunits of the Ccr4-Not complex such as Not5. The optimal presence of Not5 in polysomes is dependent upon Not4 and the deletion of Not5 leads to a dramatic reduction of polysomes. These results lead us to suggest that Not4 contributes to normal polysome levels and is important for cellular protein solubility maybe in part by ubiquitination of Rps7A.
Collapse
Affiliation(s)
- Olesya O Panasenko
- Department of Microbiology and Molecular Medicine, University of Geneva, Faculty of Medicine, 1 rue Michel Servet, 1211 Geneva 4, Switzerland.
| | | |
Collapse
|
40
|
Jitsukawa M, Kyogoku H, Ogushi S, Miyano T. Effects of proteasome inhibitors on the nucleolar size of porcine oocytes. J Reprod Dev 2011; 58:162-6. [PMID: 22095088 DOI: 10.1262/jrd.11-134a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
During the final stage of oocyte growth, the morphology of the oocyte nucleoli changes into a compact structure. The objective of this study was to determine the involvement of the proteasome, which is a large protein complex responsible for degrading intracellular proteins, in the nucleolar compaction. The mean nucleolar diameter of growing porcine oocytes (about 100 µm in diameter) was larger than that of fully grown (120 µm) oocytes (15.5 ± 0.3 vs. 13.2 ± 0.1 µm, P<0.05). When fully grown oocytes were treated with proteasome inhibitors, MG132 (10 and 20 µM) and lactacystin (100 and 200 µM), the nucleolar diameter significantly increased from 12.9 µm to 14.9-16.1 µm. In contrast, transcription inhibitors, actinomycin D (0.8-8 µM) and α-amanitin (10-100 µM) reduced the nucleolar diameter of growing oocytes to 9.4-12.4 µm. MG132 partially prevented this reduction in nucleolar diameter. These results suggest that the proteasome regulates the nucleolar size in porcine oocytes perhaps through the degradation of nucleolar proteins.
Collapse
Affiliation(s)
- Mayumi Jitsukawa
- Graduate School of Agricultural Science, Kobe University, Kobe 657-8501, Japan
| | | | | | | |
Collapse
|
41
|
Abstract
The control of ribosome biogenesis is a critical cellular nodal point, which ensures that protein synthesis is coordinated with cell growth and proliferation. Prior to their cytoplasmic assembly the 40S and 60S ribosomal subunits pass through the nucleolus and the nucleoplasm via a maturation pathway that involves a set of non-coding RNAs and non-ribosomal regulatory trans-acting factors. In mammalian cells the inventory of the required protein components is still fragmentary and it is largely unclear what drives the subcellular transitions and the exchange of protein components along the maturation pathway. However, recent data indicate that the dynamic post-translational modification by the ubiquitin-like SUMO modifier is critically involved in these processes. In particular, removal of SUMO from trans-acting factors by the SUMO-specific isopeptidase SENP3 is instrumental in the 60S maturation pathway in mammals. In an attempt to pinpoint the relevant targets of SENP3 we identified a novel SENP3-associated protein complex comprised of PELP1, TEX10 and WDR18. We demonstrated that this complex is involved in the nucleolar steps of 28S rRNA maturation and the subsequent nucleoplasmic transit of the 60S ribosomal subunit. Importantly, we found that PELP1 is a SENP3-sensitive target of SUMO and observed that lack of SENP3-mediated desumoylation prevents the nucleolar partitioning of the PELP1-TEX10-WDR18 complex. SUMO-dependent subnuclear trafficking may thus assist in coordinating the rate of ribosome formation. Here we propose that sumoylation of PELP1 serves as a quality control mechanism that restricts pre-mature loading of the PELP1-WDR18-TEX10 complex to 60S particles thereby limiting ribosome maturation. We further hypothesize that the PELP1-associated AAA-ATPase MDN1 may be part of this surveillance pathway.
Collapse
Affiliation(s)
- Elisabeth Finkbeiner
- Department of Molecular Cell Biology, Max Planck Institute of Biochemistry, Martinsried, Germany
| | | | | | | |
Collapse
|
42
|
Vilotti S, Biagioli M, Foti R, Dal Ferro M, Lavina ZS, Collavin L, Del Sal G, Zucchelli S, Gustincich S. The PML nuclear bodies-associated protein TTRAP regulates ribosome biogenesis in nucleolar cavities upon proteasome inhibition. Cell Death Differ 2011; 19:488-500. [PMID: 21921940 DOI: 10.1038/cdd.2011.118] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
TRAF and TNF receptor-associated protein (TTRAP) is a multifunctional protein that can act in the nucleus as a 5'-tyrosyl DNA phosphodiesterase and in the cytoplasm as a regulator of cell signaling. In this paper we show that in response to proteasome inhibition TTRAP accumulates in nucleolar cavities in a promyelocytic leukemia protein-dependent manner. In the nucleolus, TTRAP contributes to control levels of ribosomal RNA precursor and processing intermediates, and this phenotype is independent from its 5'-tyrosyl DNA phosphodiesterase activity. Our findings suggest a previously unidentified function for TTRAP and nucleolar cavities in ribosome biogenesis under stress.
Collapse
Affiliation(s)
- S Vilotti
- Sector of Neurobiology, International School for Advanced Studies, Via Bonomea 265, Trieste, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
43
|
Dysfunction of the ubiquitin-proteasome system in the cerebellum of aging Ts65Dn mice. Exp Neurol 2011; 232:114-8. [PMID: 21867700 DOI: 10.1016/j.expneurol.2011.08.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Revised: 07/22/2011] [Accepted: 08/08/2011] [Indexed: 01/09/2023]
Abstract
In the cerebellum of adult-aging Ts65Dn mice, a murine model of Down syndrome, Purkinje cells undergo degeneration. Searching for the cause of Purkinje cell degeneration, we have studied the ubiquitin-proteasome system (UPS) in the cerebellum of aging Ts65Dn mice. Inhibition of UPS is sufficient to induce neuron degeneration and death. Proteasome chymotrypsin-like proteolytic activity was reduced by 35% in the cerebellum of Ts65Dn mice in comparison with euploid animals. Accordingly, Western blot analysis of ubiquitin showed an increase in ubiquitinated proteins. Immunocytochemistry for ubiquitin revealed strongly positive intranuclear inclusions in Purkinje cells and large neurons of cerebellar nuclei. The Western blot analysis of ubiquitin in nuclear protein extracts confirmed the increase of ubiquitinated proteins in the cell nuclei. After FUS immunocytochemistry, large intranuclear inclusions were visible in Purkinje cells and large neurons of cerebellar nuclei in Ts65Dn mice. Together, data indicate a possible role for proteasome inhibition in the cerebellar neurodegeneration in Ts65Dn mice.
Collapse
|
44
|
Yoshikawa H, Komatsu W, Hayano T, Miura Y, Homma K, Izumikawa K, Ishikawa H, Miyazawa N, Tachikawa H, Yamauchi Y, Isobe T, Takahashi N. Splicing factor 2-associated protein p32 participates in ribosome biogenesis by regulating the binding of Nop52 and fibrillarin to preribosome particles. Mol Cell Proteomics 2011; 10:M110.006148. [PMID: 21536856 DOI: 10.1074/mcp.m110.006148] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Ribosome biogenesis starts with transcription of the large ribosomal RNA precursor (47S pre-rRNA), which soon combines with numerous factors to form the 90S pre-ribosome in the nucleolus. Although the subsequent separation of the pre-90S particle into pre-40S and pre-60S particles is critical for the production process of mature small and large ribosomal subunits, its molecular mechanisms remain undetermined. Here, we present evidence that p32, fibrillarin (FBL), and Nop52 play key roles in this separation step. Mass-based analyses combined with immunoblotting showed that p32 associated with 155 proteins including 31 rRNA-processing factors (of which nine were components of small subunit processome, and six were those of RIX1 complex), 13 chromatin remodeling components, and six general transcription factors required for RNA polymerase III-mediated transcription. Of these, a late rRNA-processing factor Nop52 interacted directly with p32. Immunocytochemical analyses demonstrated that p32 colocalized with an early rRNA-processing factor FBL or Nop52 in the nucleolus and Cajal bodies, but was excluded from the nucleolus after actinomycin D treatment. p32 was present in the pre-ribosomal fractions prepared by cell fractionation or separated by ultracentrifugation of the nuclear extract. p32 also associated with pre-rRNAs including 47S/45S and 32S pre-rRNAs. Furthermore, knockdown of p32 with a small interfering RNA slowed the early processing from 47S/45S pre-rRNAs to 18S rRNA and 32S pre-rRNA. Finally, Nop52 was found to compete with FBL for binding to p32 probably in the nucleolus. Given the fact that FBL and Nop52 are associated with pre-ribosome particles distinctly different from each other, we suggest that p32 is a new rRNA maturation factor involved in the remodeling from pre-90S particles to pre-40S and pre-60S particles that requires the exchange of FBL for Nop52.
Collapse
Affiliation(s)
- Harunori Yoshikawa
- Department of Applied Life Science, United Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
45
|
Latonen L. Nucleolar aggresomes as counterparts of cytoplasmic aggresomes in proteotoxic stress. Bioessays 2011; 33:386-95. [DOI: 10.1002/bies.201100008] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
46
|
Abstract
When cells are observed by phase contrast microscopy, nucleoli are among the most conspicuous structures. The nucleolus was formally described between 1835 and 1839, but it was another century before it was discovered to be associated with a specific chromosomal locus, thus defining it as a cytogenetic entity. Nucleoli were first isolated in the 1950s, from starfish oocytes. Then, in the early 1960s, a boomlet of studies led to one of the epochal discoveries in the modern era of genetics and cell biology: that the nucleolus is the site of ribosomal RNA synthesis and nascent ribosome assembly. This epistemologically repositioned the nucleolus as not merely an aspect of nuclear anatomy but rather as a cytological manifestation of gene action-a major heuristic advance. Indeed, the finding that the nucleolus is the seat of ribosome production constitutes one of the most vivid confluences of form and function in the history of cell biology. This account presents the nucleolus in both historical and contemporary perspectives. The modern era has brought the unanticipated discovery that the nucleolus is plurifunctional, constituting a paradigm shift.
Collapse
Affiliation(s)
- Thoru Pederson
- Program in Cell and Developmental Dynamics, Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, 01605, USA.
| |
Collapse
|
47
|
Lopez AD, Tar K, Krügel U, Dange T, Ros IG, Schmidt M. Proteasomal degradation of Sfp1 contributes to the repression of ribosome biogenesis during starvation and is mediated by the proteasome activator Blm10. Mol Biol Cell 2011; 22:528-40. [PMID: 21209318 PMCID: PMC3046052 DOI: 10.1091/mbc.e10-04-0352] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The ribosome transcription activator Sfp1 is degraded by Blm10-proteasomes. Loss of BLM10 results in increased Sfp1 protein levels, increased transcription of ribosomal genes, and increased ribosome levels upon nutrient depletion. Thus Blm10-proteasome-mediated turnover of Sfp1 is a regulatory mechanism for ribosome biosynthesis repression. The regulation of ribosomal protein (RP) gene transcription is tightly linked to the nutrient status of the cell and is under the control of metabolic signaling pathways. In Saccharomyces cerevisiae several transcriptional activators mediate efficient RP gene transcription during logarithmic growth and dissociate from RP gene promoters upon nutrient limitation. Repression of RP gene transcription appears to be regulated predominantly by posttranslational modification and cellular localization of transcriptional activators. We report here that one of these factors, Sfp1, is degraded by the proteasome and that the proteasome activator Blm10 is required for regulated Sfp1 degradation. Loss of Blm10 results in the stabilization and increased nuclear abundance of Sfp1 during nutrient limitation, increased transcription of RP genes, increased levels of RPs, and decreased rapamycin-induced repression of RP genes. Thus we conclude that proteasomal degradation of Sfp1 is mediated by Blm10 and contributes to the repression of ribosome biogenesis under nutrient depletion.
Collapse
Affiliation(s)
- Antonio Diaz Lopez
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | | | | | | | | | | |
Collapse
|
48
|
Dasuri K, Ebenezer PJ, Zhang L, Fernandez-Kim SO, Uranga RM, Gavilán E, Di Blasio A, Keller JN. Selective vulnerability of neurons to acute toxicity after proteasome inhibitor treatment: implications for oxidative stress and insolubility of newly synthesized proteins. Free Radic Biol Med 2010; 49:1290-7. [PMID: 20678570 PMCID: PMC3175605 DOI: 10.1016/j.freeradbiomed.2010.07.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2010] [Revised: 07/13/2010] [Accepted: 07/19/2010] [Indexed: 12/19/2022]
Abstract
Maintaining protein homeostasis is vital to cell viability, with numerous studies demonstrating a role for proteasome inhibition occurring during the aging of a variety of tissues and, presumably, contributing to the disruption of cellular homeostasis during aging. In this study we sought to elucidate the differences between neurons and astrocytes in regard to basal levels of protein synthesis, proteasome-mediated protein degradation, and sensitivity to cytotoxicity after proteasome inhibitor treatment. In these studies we demonstrate that neurons have an increased vulnerability, compared to astrocyte cultures, to proteasome-inhibitor-induced cytotoxicity. No significant difference was observed between these two cell types in regard to the basal rates of protein synthesis, or basal rates of protein degradation, in the pool of short-lived proteins. After proteasome inhibitor treatment neuronal crude lysates were observed to undergo greater increases in the levels of ubiquitinated and oxidized proteins and selectively exhibited increased levels of newly synthesized proteins accumulating within the insoluble protein pool, compared to astrocytes. Together, these data suggest a role for increased oxidized proteins and sequestration of newly synthesized proteins in the insoluble protein pool, as potential mediators of the selective neurotoxicity after proteasome inhibitor treatment. The implications for neurons exhibiting increased sensitivity to acute proteasome inhibitor exposure, and the corresponding changes in protein homeostasis observed after proteasome inhibition, are discussed in the context of both aging and age-related disorders of the nervous system.
Collapse
Affiliation(s)
- Kalavathi Dasuri
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana, USA
| | - Philip J. Ebenezer
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana, USA
| | - Le Zhang
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana, USA
| | - Sun Ok Fernandez-Kim
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana, USA
| | - Romina M. Uranga
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Universidad Nacional del sur and Consejo Nacional de Investigaciones Científicas y Técnicas, Bahía Blanca,Argentina
| | - Elena Gavilán
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana, USA
| | - Alessia Di Blasio
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana, USA
| | - Jeffrey N Keller
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana, USA
- Corresponding author: Dr Jeffrey N. Keller, Pennington Biomedical Research Center/LSU System, 6400 Perkins Road, Baton Rouge, LA 70808-4124, (P): 225-763-3190; (E):
| |
Collapse
|
49
|
Wild T, Horvath P, Wyler E, Widmann B, Badertscher L, Zemp I, Kozak K, Csucs G, Lund E, Kutay U. A protein inventory of human ribosome biogenesis reveals an essential function of exportin 5 in 60S subunit export. PLoS Biol 2010; 8:e1000522. [PMID: 21048991 PMCID: PMC2964341 DOI: 10.1371/journal.pbio.1000522] [Citation(s) in RCA: 154] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2010] [Accepted: 09/03/2010] [Indexed: 12/20/2022] Open
Abstract
The assembly of ribosomal subunits in eukaryotes is a complex, multistep process so far mostly studied in yeast. In S. cerevisiae, more than 200 factors including ribosomal proteins and trans-acting factors are required for the ordered assembly of 40S and 60S ribosomal subunits. To date, only few human homologs of these yeast ribosome synthesis factors have been characterized. Here, we used a systematic RNA interference (RNAi) approach to analyze the contribution of 464 candidate factors to ribosomal subunit biogenesis in human cells. The screen was based on visual readouts, using inducible, fluorescent ribosomal proteins as reporters. By performing computer-based image analysis utilizing supervised machine-learning techniques, we obtained evidence for a functional link of 153 human proteins to ribosome synthesis. Our data show that core features of ribosome assembly are conserved from yeast to human, but differences exist for instance with respect to 60S subunit export. Unexpectedly, our RNAi screen uncovered a requirement for the export receptor Exportin 5 (Exp5) in nuclear export of 60S subunits in human cells. We show that Exp5, like the known 60S exportin Crm1, binds to pre-60S particles in a RanGTP-dependent manner. Interference with either Exp5 or Crm1 function blocks 60S export in both human cells and frog oocytes, whereas 40S export is compromised only upon inhibition of Crm1. Thus, 60S subunit export is dependent on at least two RanGTP-binding exportins in vertebrate cells.
Collapse
Affiliation(s)
- Thomas Wild
- Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
- Molecular Life Science Ph.D. Program, Zurich, Switzerland
| | - Peter Horvath
- Light Microscopy Center, RISC, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Emanuel Wyler
- Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
- Molecular Life Science Ph.D. Program, Zurich, Switzerland
| | - Barbara Widmann
- Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
- Molecular Life Science Ph.D. Program, Zurich, Switzerland
| | - Lukas Badertscher
- Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
- Molecular Life Science Ph.D. Program, Zurich, Switzerland
| | - Ivo Zemp
- Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
| | - Karol Kozak
- Light Microscopy Center, RISC, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Gabor Csucs
- Light Microscopy Center, RISC, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Elsebet Lund
- University of Wisconsin, Madison, Wisconsin, United States of America
| | - Ulrike Kutay
- Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
- * E-mail:
| |
Collapse
|
50
|
Latonen L, Moore HM, Bai B, Jäämaa S, Laiho M. Proteasome inhibitors induce nucleolar aggregation of proteasome target proteins and polyadenylated RNA by altering ubiquitin availability. Oncogene 2010; 30:790-805. [PMID: 20956947 DOI: 10.1038/onc.2010.469] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The ubiquitin-proteasome pathway is essential for most cellular processes, including protein quality control, cell cycle, transcription, signaling, protein transport, DNA repair and stress responses. Hampered proteasome activity leads to the accumulation of polyubiquitylated proteins, endoplastic reticulum (ER) stress and even cell death. The ability of chemical proteasome inhibitors (PIs) to induce apoptosis is utilized in cancer therapy. During PI treatment, misfolded proteins accrue to cytoplasmic aggresomes. The formation of aggresome-like structures in the nucleus has remained obscure. We identify here a nucleolus-associated RNA-protein aggregate (NoA) formed by the inhibition of proteasome activity in mammalian cells. The aggregate forms within the nucleolus and is dependent on nucleolar integrity, yet is a separate structure, lacking nucleolar marker proteins, ribosomal RNA (rRNA) and rRNA synthesis activity. The NoAs contain polyadenylated RNA, conjugated ubiquitin and numerous nucleoplasmic proteasome target proteins. Several of these are key factors in oncogenesis, including transcription factors p53 and retinoblastoma protein (Rb), several cell cycle-regulating cyclins and cyclin-dependent kinases (CDKs), and stress response kinases ataxia-telangiectasia mutated (ATM) and Chk1. The aggregate formation depends on ubiquitin availability, as shown by modulating the levels of ubiquitin and deubiquitinases. Furthermore, inhibition of chromosome region maintenance 1 protein homolog (CRM1) export pathway aggravates the formation of NoAs. Taken together, we identify here a novel nuclear stress body, which forms upon proteasome inactivity within the nucleolus and is detectable in mammalian cell lines and in human tissue. These findings show that the nucleolus controls protein and RNA surveillance and export by the ubiquitin pathway in a previously unidentified manner, and provide mechanistic insight into the cellular effects of PIs.
Collapse
Affiliation(s)
- L Latonen
- Molecular Cancer Biology Program and Haartman Institute, University of Helsinki, Helsinki, Finland
| | | | | | | | | |
Collapse
|