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Zhang C, Xiong Y, Zeng L, Peng Z, Liu Z, Zhan H, Yang Z. The Role of Non-coding RNAs in Viral Myocarditis. Front Cell Infect Microbiol 2020; 10:312. [PMID: 32754448 PMCID: PMC7343704 DOI: 10.3389/fcimb.2020.00312] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Accepted: 05/22/2020] [Indexed: 12/13/2022] Open
Abstract
Viral myocarditis (VMC) is a disease characterized as myocardial parenchyma or interstitium inflammation caused by virus infection, especially Coxsackievirus B3 (CVB3) infection, which has no accurate non-invasive examination for diagnosis and specific drugs for treatment. The mechanism of CVB3-induced VMC may be related to direct myocardial damage of virus infection and extensive damage of abnormal immune response after infection. Non-coding RNA (ncRNA) refers to RNA that is not translated into protein and plays a vital role in many biological processes. There is expanding evidence to reveal that ncRNAs regulate the occurrence and development of VMC, which may provide new treatment or diagnosis targets. In this review, we mainly demonstrate an overview of the potential role of ncRNAs in the pathogenesis, diagnosis and treatment of CVB3-induced VMC.
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Affiliation(s)
- Cong Zhang
- Division of Emergency Medicine, Department of Emergency Intensive Care Unit, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.,Department of Cardiology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.,NHC Key Laboratory on Assisted Circulation (Sun Yat-sen University), Guangzhou, China
| | - Yan Xiong
- Division of Emergency Medicine, Department of Emergency Intensive Care Unit, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Lijin Zeng
- Division of Emergency Medicine, Department of Emergency Intensive Care Unit, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.,Department of Cardiology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.,NHC Key Laboratory on Assisted Circulation (Sun Yat-sen University), Guangzhou, China
| | - Zhihua Peng
- Division of Emergency Medicine, Department of Emergency Intensive Care Unit, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.,Department of Cardiology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.,NHC Key Laboratory on Assisted Circulation (Sun Yat-sen University), Guangzhou, China
| | - Zhihao Liu
- Division of Emergency Medicine, Department of Emergency Intensive Care Unit, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Hong Zhan
- Division of Emergency Medicine, Department of Emergency Intensive Care Unit, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Zhen Yang
- Division of Emergency Medicine, Department of Emergency Intensive Care Unit, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.,Department of Cardiology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.,NHC Key Laboratory on Assisted Circulation (Sun Yat-sen University), Guangzhou, China
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2
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Bourgeois Y, Boissinot S. Selection at behavioural, developmental and metabolic genes is associated with the northward expansion of a successful tropical colonizer. Mol Ecol 2019; 28:3523-3543. [PMID: 31233650 DOI: 10.1111/mec.15162] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Accepted: 05/28/2019] [Indexed: 02/06/2023]
Abstract
What makes a species able to colonize novel environments? This question is key to understand the dynamics of adaptive radiations and ecological niche shifts, but the mechanisms that underlie expansion into novel habitats remain poorly understood at a genomic scale. Lizards from the genus Anolis are typically tropical, and the green anole (Anolis carolinensis) constitutes an exception since it expanded into temperate North America from subtropical Florida. Thus, we used the green anole as a model to investigate signatures of selection associated with colonization of a new environment, namely temperate North America. To this end, we analysed 29 whole-genome sequences, covering the entire native range of the species. We used a combination of recent methods to quantify both positive and balancing selection in northern populations, including FST outlier methods, machine learning and ancestral recombination graphs. We naively scanned for genes of interest and assessed the overlap between multiple tests. Strikingly, we identified many genes involved in behaviour, suggesting that the recent successful colonization of northern environments may have been linked to behavioural shifts as well as physiological adaptation. Using a candidate genes strategy, we determined that genes involved in response to cold or behaviour displayed more frequently signals of selection, while controlling for local recombination rate, gene clustering and gene length. In addition, we found signatures of balancing selection at immune genes in all investigated genetic groups, but also at genes involved in neuronal and anatomical development.
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Affiliation(s)
- Yann Bourgeois
- New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
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3
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Regulation of autoimmune disease by the E3 ubiquitin ligase Itch. Cell Immunol 2019; 340:103916. [PMID: 31126634 DOI: 10.1016/j.cellimm.2019.04.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 04/03/2019] [Indexed: 12/14/2022]
Abstract
Itch is a HECT type E3 ubiquitin ligase that is required to prevent the development of autoimmune disease in both mice and humans. Itch is expressed in most mammalian cell types, and, based on published data, it regulates many cellular pathways ranging from T cell differentiation to liver tumorigenesis. Since 1998, when Itch was first discovered, hundreds of publications have described mechanisms through which Itch controls various biologic activities in both immune and non-immune cells. Other studies have provided insight into how Itch catalytic activity is regulated. However, while autoimmunity is the primary clinical feature that occurs in both mice and humans lacking Itch, and Itch control of immune cell function has been well-studied, it remains unclear how Itch prevents the emergence of autoimmune disease. In this review, we explore recent discoveries that advance our understanding of how Itch regulates immune cell biology, and the extent to which these clarify how Itch prevents autoimmune disease. Additionally, we discuss how molecular regulators of Itch impact its ability to control these processes, as this may provide clues on how to therapeutically target Itch to treat patients with autoimmune disease.
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4
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Abstract
Itch or itchy E3 ubiquitin ligase was initially discovered by genetic studies on the mouse coat color changes, and its deletion results in an itchy phenotype with constant skin scratching and multi-organ inflammation. It is a member of the homologous to E6-associated protein C-terminus (HECT)-type family of E3 ligases, with the protein-interacting WW-domains for the recruitment of substrate and the HECT domain for the transfer of ubiquitin to the substrate. Since its discovery, numerous studies have demonstrated that Itch is involved in the control of many aspects of immune responses including T-cell activation and tolerance and T-helper cell differentiation. Itch is also implicated in other biological contexts such as tumorigenesis, development, and stress responses. Many signaling pathways are regulated by Itch-promoted ubiquitylation of diverse target proteins. Itch is also involved in human diseases. Here, we discuss the major progress in understanding the biological significance of Itch-promoted protein ubiquitylation in the immune and other systems and in Itch-mediated regulation of signal transduction.
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Affiliation(s)
- Daisuke Aki
- Institute for Immunology, Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, China.,Division of Cell Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA, USA
| | - Wen Zhang
- Institute for Immunology, Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, China
| | - Yun-Cai Liu
- Institute for Immunology, Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, China.,Division of Cell Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA, USA
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5
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Multifaceted role of the ubiquitin ligase Itch in immune regulation. Immunol Cell Biol 2015; 93:452-60. [DOI: 10.1038/icb.2014.118] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Revised: 12/10/2014] [Accepted: 12/10/2014] [Indexed: 12/17/2022]
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6
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Jutzi JS, Bogeska R, Nikoloski G, Schmid CA, Seeger TS, Stegelmann F, Schwemmers S, Gründer A, Peeken JC, Gothwal M, Wehrle J, Aumann K, Hamdi K, Dierks C, Kamar Wang W, Döhner K, Jansen JH, Pahl HL. MPN patients harbor recurrent truncating mutations in transcription factor NF-E2. ACTA ACUST UNITED AC 2013; 210:1003-19. [PMID: 23589569 PMCID: PMC3646501 DOI: 10.1084/jem.20120521] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The molecular etiology of myeloproliferative neoplasms (MPNs) remains incompletely understood, despite recent advances incurred through the discovery of several different mutations in MPN patients. We have recently described overexpression of the transcription factor NF-E2 in MPN patients and shown that elevated NF-E2 levels in vivo cause an MPN phenotype and predispose to leukemic transformation in transgenic mice. We report the presence of acquired insertion and deletion mutations in the NF-E2 gene in MPN patients. These result in truncated NF-E2 proteins that enhance wild-type (WT) NF-E2 function and cause erythrocytosis and thrombocytosis in a murine model. NF-E2 mutant cells acquire a proliferative advantage, witnessed by clonal dominance over WT NF-E2 cells in MPN patients. Our data underscore the role of increased NF-E2 activity in the pathophysiology of MPNs.
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Affiliation(s)
- Jonas S Jutzi
- Department of Hematology/Oncology, University Hospital Freiburg, 79106 Freiburg, Germany
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7
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Gulino A, Di Marcotullio L, Canettieri G, De Smaele E, Screpanti I. Hedgehog/Gli Control by Ubiquitination/Acetylation Interplay. HEDGEHOG SIGNALING 2012; 88:211-27. [DOI: 10.1016/b978-0-12-394622-5.00009-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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8
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Chung KM, Huang CH, Cheng JH, Tsai CH, Suen CS, Hwang MJ, Chen X. Proline in transmembrane domain of type II protein DPP-IV governs its translocation behavior through endoplasmic reticulum. Biochemistry 2011; 50:7909-18. [PMID: 21834515 DOI: 10.1021/bi200605h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A transmembrane domain (TMD) at the N-terminus of a membrane protein is a signal sequence that targets the protein to the endoplasmic reticulum (ER) membrane. Proline is found more frequently in TM helices compared to water-soluble helices. To investigate the effects of proline on protein translocation and integration in mammalian cells, we made proline substitutions throughout the TMD of dipeptidyl peptidase IV, a type II membrane protease with a single TMD at its N-terminus. The proteins were expressed and their capacities for targeting and integrating into the membrane were measured in both mammalian cells and in vitro translation systems. Three proline substitutions in the central region of the TMD resulted in various defects in membrane targeting and/or integration. The replacement of proline with other amino acids of similar hydrophobicity rescued both the translocation and anchoring defects of all three proline mutants, indicating that conformational change caused by proline is a determining factor. Increasing hydrophobicity of the TMD by replacing other residues with more hydrophobic residues also effectively reversed the translocation and integration defects. Intriguingly, increasing hydrophobicity at the C-terminal end of the TMD rescued much more effectively than it did at the N-terminal end. Thus, the effect of proline on translocation and integration of the TMD is not determined solely by its conformation and hydrophobicity, but also by the location of proline in the TMD, the location of highly hydrophobic residues, and the relative position of the proline to other proline residues in the TMD.
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Affiliation(s)
- Kuei-Min Chung
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Miaoli County 350, Taiwan, ROC
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9
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Chung KM, Cheng JH, Suen CS, Huang CH, Tsai CH, Huang LH, Chen YR, Wang AHJ, Jiaang WT, Hwang MJ, Chen X. The dimeric transmembrane domain of prolyl dipeptidase DPP-IV contributes to its quaternary structure and enzymatic activities. Protein Sci 2011; 19:1627-38. [PMID: 20572019 DOI: 10.1002/pro.443] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Dipeptidyl peptidase IV (DPP-IV) is a drug target in the treatment of human type II diabetes. It is a type II membrane protein with a single transmembrane domain (TMD) anchoring the extracellular catalytic domain to the membrane. DPP-IV is active as a dimer, with two dimer interacting surfaces located extracellularly. In this study, we demonstrate that the TM of DPP-IV promotes DPP-IV dimerization and rescues monomeric DPP-IV mutants into partial dimers, which is specific and irreplaceable by TMs of other type II membrane proteins. By bioluminescence resonance energy transfer (BRET) and peptide electrophoresis, we found that the TM domain of DPP-IV is dimerized in mammalian cells and in vitro. The TM dimer interaction is very stable, based on our results with TM site-directed mutagenesis. None of the mutations, including the introduction of two prolines, resulted in their complete disruption to monomers. However, these TM proline mutations result in a significant reduction of DPP-IV enzymatic activity, comparable to what is found with mutations near the active site. A systematic analysis of TM structures deposited in the Protein Data Bank showed that prolines in the TM generally produce much bigger kinking angles than occur in nonproline-containing TMs. Thus, the proline-dependent reduction in enzyme activity may result from propagated conformational changes from the TM to the extracellular active site. Our results demonstrate that TM dimerization and conformation contribute significantly to the structure and activity of DPP-IV. Optimal enzymatic activity of DPP-IV requires an optimal interaction of all three dimer interfaces, including its TM.
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Affiliation(s)
- Kuei-Min Chung
- Division of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Zhu Nan town, Miaoli County, Taiwan, Republic of China
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10
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Flasza M, Nguyen Huu NS, Mazaleyrat S, Clémence S, Villemant C, Clarke R, Baron M. Regulation of the nuclear localization of the human Nedd4-related WWP1 protein by Notch. Mol Membr Biol 2009; 23:269-76. [PMID: 16785210 DOI: 10.1080/09687860600665010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Nedd4 family ubiquitin ligases regulate trafficking and degradation of numerous target substrates in different cellular compartments, including at the plasma membrane, in endosomes, in the secretory pathway and in the nucleus. WWP1 is a Nedd4 family protein closely related to mouse Itch and Drosophila Su(dx), both of which have been shown to regulate the Notch receptor. To investigate the possibility that WWP1 is also associated with Notch signalling we coexpressed human Notch1 and WWP1 in mouse myoblast cells. We found that WWP1 could localize to both the nucleus and cytoplasm in a context dependent manner. Coexpression of human Notch1 (hN1) depleted WWP1 from the nucleus to colocalise with hN1 in early endosomes, dependent on the presence of the C-terminal HECT domain. Furthermore we found that full-length expressed WWP1 could interact in vitro with the cytoplasmic domain of human Notch1. The Notch receptor has multiple roles in development, mediating a short-range signal that controls cell fate and pattern formation. The canonical Notch signal involves proteolytic release of the soluble Notch intracellular domain and the activation by the latter of the transcription factor Suppressor of Hairless/CBF-1 in the nucleus. This pathway does not however account for all of the activity of Notch. The ability of Notch to regulate the nuclear localization of WWP1 suggests a possible alternative mechanism by which Notch may communicate a signal to the nucleus. Drosophila Notch similarly regulated the nuclear localization of the Drosophila Nedd4 family protein, Suppressor of deltex, implying conservation of this mechanism during evolution.
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Affiliation(s)
- Marzena Flasza
- University of Manchester, Faculty of Life Sciences, Michael Smith Building, Manchester
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11
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Itch regulates p45/NF-E2 in vivo by Lys63-linked ubiquitination. Biochem Biophys Res Commun 2008; 375:326-30. [DOI: 10.1016/j.bbrc.2008.07.164] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2008] [Accepted: 07/29/2008] [Indexed: 11/22/2022]
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12
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Abstract
Accumulating evidence suggests that E3 ubiquitin ligases play important roles in cancer development. In this article, we provide a comprehensive summary of the roles of the Nedd4-like family of E3 ubiquitin ligases in human cancer. There are nine members of the Nedd4-like E3 family, all of which share a similar structure, including a C2 domain at the N-terminus, two to four WW domains in the middle of the protein, and a homologous to E6-AP COOH terminus domain at the C-terminus. The assertion that Nedd4-like E3s play a role in cancer is supported by the overexpression of Smurf2 in esophageal squamous cell carcinoma, WWP1 in prostate and breast cancer, Nedd4 in prostate and bladder cancer, and Smurf1 in pancreatic cancer. Because Nedd4-like E3s regulate ubiquitin-mediated trafficking, lysosomal or proteasomal degradation, and nuclear translocation of multiple proteins, they modulate important signaling pathways involved in tumorigenesis like TGFbeta, EGF, IGF, VEGF, SDF-1, and TNFalpha. Additionally, several Nedd4-like E3s directly regulate various cancer-related transcription factors from the Smad, p53, KLF, RUNX, and Jun families. Interestingly, multiple Nedd4-like E3s show ligase independent function. Furthermore, Nedd4-like E3s themselves are frequently regulated by phosphorylation, ubiquitination, translocation, and transcription in cancer cells. Because the regulation and biological output of these E3s is such a complex process, study of the role of these E3s in cancer development poses some challenges. However, understanding the oncogenic potential of these E3s may facilitate the identification and development of biomarkers and drug targets in human cancer.
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Affiliation(s)
- Ceshi Chen
- The Center for Cell Biology and Cancer Research, Albany Medical College, 47, New Scotland Ave., Albany, NY 12208, USA.
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13
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Matesic LE, Copeland NG, Jenkins NA. Itchy Mice: The Identification of a New Pathway for the Development of Autoimmunity. Curr Top Microbiol Immunol 2008; 321:185-200. [DOI: 10.1007/978-3-540-75203-5_9] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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14
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Fock EL, Yan F, Pan S, Chong BH. NF-E2-mediated enhancement of megakaryocytic differentiation and platelet production in vitro and in vivo. Exp Hematol 2007; 36:78-92. [PMID: 17923245 DOI: 10.1016/j.exphem.2007.08.015] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2007] [Revised: 08/07/2007] [Accepted: 08/09/2007] [Indexed: 12/31/2022]
Abstract
OBJECTIVE NF-E2 is a prime regulator of megakaryocyte (MK) terminal differentiation and platelet release. By overexpressing the p45 subunit of NF-E2, we aim to increase the proportion of mature MKs and the potential for platelet production in vitro and in vivo. METHODS Retroviral vectors expressing p45-NF-E2 together with the enhanced green fluorescent protein (eGFP) were used to transduce murine bone marrow cells (BMCs). Aspects of MK differentiation, proliferation, proplatelet, and platelet production were evaluated. RESULTS Compared to controls, a higher proportion of BMCs overexpressing p45-NF-E2 were found to express the MK markers CD41, CD42a, and CD42b, with some effect on cell proliferation. Early MK differentiation, characterized by colony-forming unit (CFU)-MK formation, was enhanced by p45-NF-E2 overexpression at the expense of CFU-granulocyte macrophage development. An increased number of acetylcholinesterase(+) MKs was also observed in NF-E2(++) cultures. Although endomitosis was found not to be affected, the resultant upregulation of NF-E2 target genes was also followed by significant increases in proplatelet and functional platelet production. Transplantation of enriched MK progenitor cells overexpressing p45-NF-E2 into lethally irradiated mice resulted in a threefold increase in eGFP(+)/NF-E2(++) platelet production in vivo over 10 days, although no appreciable expansion in their number was observed over 32 days. CONCLUSION These results suggest that enforced expression of p45-NF-E2 selectively enhances many aspects of MK differentiation, including MK maturation, proplatelet formation, and platelet release. In addition, p45 overexpression increases MK commitment during early megakaryopoiesis, while inhibiting white blood cell differentiation.
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Affiliation(s)
- Ee-ling Fock
- Centre for Vascular Research, Department of Medicine, St. George Clinical School, University of New South Wales, Sydney, Australia
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15
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Liu YC. The E3 ubiquitin ligase Itch in T cell activation, differentiation, and tolerance. Semin Immunol 2007; 19:197-205. [PMID: 17433711 PMCID: PMC2680672 DOI: 10.1016/j.smim.2007.02.003] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2006] [Accepted: 02/16/2007] [Indexed: 12/11/2022]
Abstract
Tagging a small molecule ubiquitin to a protein substrate, or protein ubiquitination, plays an important role in the immune responses. This process is catalyzed by a cascade of enzymatic reactions, with the E3 ubiquitin ligases being the critical enzymes that determine the specificity of substrate recognition. The E3 ligase Itch was identified from a mutant mouse which displays skin scratching and abnormal immune disorders. In the past few years, much progress has been made in our understanding of Itch-promoted protein ubiquitination, modulation of its ligase activity by upstream kinases, and the kinase-ligase interaction in T cell differentiation and tolerance induction.
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Affiliation(s)
- Yun-Cai Liu
- Division of Cell Biololgy, La Jolla Institute for Allergy and Immunology, 9420 Athena Circle, La Jolla, CA 92037, USA.
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16
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Lee HJ, Chen YS, Chou CY, Chien CH, Lin CH, Chang GG, Chen X. Investigation of the dimer interface and substrate specificity of prolyl dipeptidase DPP8. J Biol Chem 2006; 281:38653-62. [PMID: 17040910 DOI: 10.1074/jbc.m603895200] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
DPP8 belongs to the family of prolyl dipeptidases, which are capable of cleaving the peptide bond after a penultimate proline residue. Unlike DPP-IV, a drug target for type II diabetes, no information is available on the crystal structure of DPP8, the regulation of its enzymatic activity, or its substrate specificity. In this study, using analytical ultracentrifugation and native gel electrophoresis, we show that the DPP8 protein is predominantly dimeric when purified or in the cell extracts. Four conserved residues in the C-terminal loop of DPP8 (Phe(822), Val(833), Tyr(844), and His(859)), corresponding to those located at the dimer interface of DPP-IV, were individually mutated to Ala. Surprisingly, unlike DPP-IV, these single-site mutations abolished the enzymatic activity of DPP8 without disrupting its quaternary structure, indicating that dimerization itself is not sufficient for the optimal enzymatic activity of DPP8. Moreover, these mutations not only decreased k(cat), as did the corresponding DPP-IV mutations, but also dramatically increased K(m). We further show that the K(m) effect is independent of the substrate assayed. Finally, we identified the distinctive and strict substrate selectivity of DPP8 for hydrophobic or basic residues at the P2 site, which is in sharp contrast to the much less discriminative substrate specificity of DPP-IV. Our study has identified the residues absolutely required for the optimal activity of DPP8 and its unique substrate specificity. This study extends the functional importance of the C-terminal loop to the whole family of prolyl dipeptidases.
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Affiliation(s)
- Hong-Jen Lee
- Division of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Zhu Nan Town, Miaoli Co., Taiwan 350, Republic of China
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17
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Mouchantaf R, Azakir BA, McPherson PS, Millard SM, Wood SA, Angers A. The ubiquitin ligase itch is auto-ubiquitylated in vivo and in vitro but is protected from degradation by interacting with the deubiquitylating enzyme FAM/USP9X. J Biol Chem 2006; 281:38738-47. [PMID: 17038327 DOI: 10.1074/jbc.m605959200] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Itch is a ubiquitin ligase that has been implicated in the regulation of a number of cellular processes. We previously have identified Itch as a binding partner for the endocytic protein Endophilin and found it to be localized to endosomes. Using affinity purification coupled to mass spectrometry, we have now identified the ubiquitin-protease FAM/USP9X as a binding partner of Itch. The association between Itch and FAM/USP9X was confirmed in vitro by glutathione S-transferase pulldown and in vivo through coimmunoprecipation. Itch and FAM partially colocalize in COS-7 cells at the trans-Golgi network and in peripheral vesicles. We mapped the FAM-binding domain on Itch to the WW domains, a region known to be involved in substrate recognition. However, transient overexpression of FAM/USP9X resulted in the deubiquitylation of Itch. Moreover, we show that Itch auto-ubiquitylation leads to its degradation in the proteasome. By examining the amounts of Itch and FAM in various cell lines and rat tissues, a positive correlation was found in the expression of both proteins. This observation suggests that the levels of FAM expression could have an influence on Itch in cells. Experimental decrease in FAM levels by RNA interference leads to a significant reduction in intracellular levels of endogenous Itch, which can be prevented by treatment with the proteasome inhibitor lactacystin. Accordingly, overexpression of FAM/USP9X resulted in a marked increase in endogenous Itch levels. These results demonstrate an intriguing interplay between a ubiquitin ligase and a ubiquitin protease, based on direct interaction between the two proteins.
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Affiliation(s)
- Rania Mouchantaf
- Départment de sciences biologiques, Université de Montréal, Station Centre-Ville, Montreal, Quebec H3C 3J7, Canada
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18
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Bresnick EH, Johnson KD, Kim SI, Im H. Establishment and regulation of chromatin domains: mechanistic insights from studies of hemoglobin synthesis. PROGRESS IN NUCLEIC ACID RESEARCH AND MOLECULAR BIOLOGY 2006; 81:435-71. [PMID: 16891178 DOI: 10.1016/s0079-6603(06)81011-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Emery H Bresnick
- Department of Pharmacology, University of Wisconsin Medical School, 383 Medical Sciences Center, Madison, Wisconsin 53706, USA
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Shyu YC, Lee TL, Ting CY, Wen SC, Hsieh LJ, Li YC, Hwang JL, Lin CC, Shen CKJ. Sumoylation of p45/NF-E2: nuclear positioning and transcriptional activation of the mammalian beta-like globin gene locus. Mol Cell Biol 2005; 25:10365-78. [PMID: 16287851 PMCID: PMC1291221 DOI: 10.1128/mcb.25.23.10365-10378.2005] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
NF-E2 is a transcription activator for the regulation of a number of erythroid- and megakaryocytic lineage-specific genes. Here we present evidence that the large subunit of mammalian NF-E2, p45, is sumoylated in vivo in human erythroid K562 cells and in mouse fetal liver. By in vitro sumoylation reaction and DNA transfection experiments, we show that the sumoylation occurs at lysine 368 (K368) of human p45/NF-E2. Furthermore, p45 sumoylation enhances the transactivation capability of NF-E2, and this is accompanied by an increase of the NF-E2 DNA binding affinity. More interestingly, we have found that in K562 cells, the beta-globin gene loci in the euchromatin regions are predominantly colocalized with the nuclear bodies promyelocytic leukemia protein (PML) oncogenic domains that are enriched with the PML, SUMO-1, RNA polymerase II, and sumoylatable p45/NF-E2. Chromatin immunoprecipitation assays further showed that the intact sumoylation site of p45/NF-E2 is required for its binding to the DNase I-hypersensitive sites of the beta-globin locus control region. Finally, we demonstrated by stable transfection assay that only the wild-type p45, but not its mutant form p45 (K368R), could efficiently rescue beta-globin gene expression in the p45-null, erythroid cell line CB3. These data together point to a model of mammalian beta-like globin gene activation by sumoylated p45/NF-E2 in erythroid cells.
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Affiliation(s)
- Yu-Chiau Shyu
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei 115, Taiwan, Republic of China
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Angers A, Ramjaun AR, McPherson PS. The HECT domain ligase itch ubiquitinates endophilin and localizes to the trans-Golgi network and endosomal system. J Biol Chem 2003; 279:11471-9. [PMID: 14684745 DOI: 10.1074/jbc.m309934200] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Endophilin A1 is an SH3 domain-containing protein functioning in membrane trafficking on the endocytic pathway. We have identified the E3 ubiquitin ligase itch/AIP4 as an endophilin A1-binding partner. Itch belongs to the Nedd4/Rsp5p family of proteins and contains an N-terminal C2 domain, four WW domains and a catalytic HECT domain. Unlike other Nedd4/Rsp5p family members, itch possesses a short proline-rich domain that mediates its binding to the SH3 domain of endophilin A1. Itch ubiquitinates endophilin A1 and the SH3/proline-rich domain interaction facilitates this activity. Interestingly, itch co-localizes with markers of the endosomal system in a C2 domain-dependent manner and upon EGF stimulation, endophilin A1 translocates to an EGF-positive endosomal compartment where it colocalizes with itch. Moreover, EGF treatment of cells stimulates endophilin A1 ubiquitination. We have thus identified endophilin A1 as a substrate for the endosome-localized ubiquitin ligase itch. This interaction may be involved in ubiquitin-mediated sorting mechanisms operating at the level of endosomes.
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Affiliation(s)
- Annie Angers
- Department of Neurology and Neurosurgery, Montréal Neurological Institute, McGill University, 3801 University St., Montréal, Quebec H3A 2B4, Canada.
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21
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Kiekhaefer CM, Boyer ME, Johnson KD, Bresnick EH. A WW domain-binding motif within the activation domain of the hematopoietic transcription factor NF-E2 is essential for establishment of a tissue-specific histone modification pattern. J Biol Chem 2003; 279:7456-61. [PMID: 14597626 DOI: 10.1074/jbc.m309750200] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Histone H3 methylated at lysine 4 (H3-meK4) co-localizes with hyperacetylated histones H3 and H4 in transcriptionally active chromatin, but mechanisms that establish H3-meK4 are poorly understood. Previously, we showed that the hematopoietic-specific activator NF-E2, which is required for beta-globin transcription in erythroleukemia cells, induces histone H3 hyperacetylation and H3-meK4 at the adult beta-globin genes (betamajor and betaminor). Chromatin immunoprecipitation analysis indicated that NF-E2 occupies hypersensitive site two (HS2) of the beta-globin locus control region. The mechanism of NF-E2-mediated chromatin modification was investigated by complementation analysis in NF-E2-null CB3 erythroleukemia cells. The activation domain of the hematopoietic-specific subunit of NF-E2 (p45/NF-E2) contains two WW domain-binding motifs (PXY-1 and PXY-2). PXY-1 is required for activation of beta-globin transcription. Here, we determined which step in NF-E2-dependent transactivation is PXY-1-dependent. A p45/NF-E2 mutant lacking 42 amino acids of the activation domain, including both PXY motifs, and a mutant lacking only PXY-1 were impaired in inducing histone H3 hyperacetylation, H3-meK4, and RNA polymerase II recruitment. The PXY motifs were not required for transactivation in the context of a GAL4 DNA-binding domain fusion to p45/NF-E2 in transient transfection assays. As the PXY-1 mutant occupied HS2 normally, the chromatin modification defect occurred post-DNA binding. PXY-1 was not required for recruitment of the histone acetyltransferases cAMP-responsive element-binding protein-binding protein (CBP) and p300 to HS2. These results indicate that PXY-1 confers chromatin-specific transcriptional activation via interaction with a co-regulator distinct from CBP/p300 or by regulating CBP/p300 function.
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Affiliation(s)
- Carol M Kiekhaefer
- University of Wisconsin Medical School, Department of Pharmacology, Madison, Wisconsin 53706, USA
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22
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Lanzara C, Ficarella R, Totaro A, Chen X, Roberto R, Perrotta S, Lasalandra C, Gasparini P, Iolascon A, Carella M. Congenital dyserythropoietic anemia type II: exclusion of seven candidate genes. Blood Cells Mol Dis 2003; 30:22-9. [PMID: 12667984 DOI: 10.1016/s1079-9796(03)00009-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Congenital dyserythropoietic anemias (CDA) are genetic disorders characterized by anemia and ineffective erythropoiesis. Three main types of CDA have been distinguished: CDA I, CDAII and CDA III, whose loci have been already mapped. After the identification of the locus for CDA II, also known as HEMPAS (hereditary erythroblast multinuclearity with positive acidified serum test), on the long arm of chromosome 20 (20q11.2) we have analyzed by a mutational search seven candidate genes in a large series of CDA II patients. In particular, the following genes have been investigated: integrin beta 4 binding protein, ribophorin II, ubiquitin protein ligase ITCH, mannosil-oligosaccharide alpha-1,2-mannosidase like protein, erythrocyte protein band 4.1 like protein, zinc finger protein PLAGL2, and finally novel zinc finger protein. None of them resulted as the causative gene but several protein variants and DNA polymorphisms have been identified. These data exclude the role of the above mentioned genes in causing CDA II and add further information in the process of cloning the CDA II gene.
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MESH Headings
- Anemia, Dyserythropoietic, Congenital/classification
- Anemia, Dyserythropoietic, Congenital/genetics
- Anemia, Dyserythropoietic, Congenital/pathology
- Chromatography, High Pressure Liquid
- Chromosome Mapping
- Chromosomes, Human, Pair 20/genetics
- Erythrocytes/pathology
- Erythropoiesis/genetics
- Genetic Linkage/genetics
- Genetic Predisposition to Disease/genetics
- Humans
- Mutation
- Polymerase Chain Reaction
- Polymorphism, Genetic
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Affiliation(s)
- Carmela Lanzara
- TIGEM (Telethon Institute of Genetics and Medicine), 80131 Naples, Italy
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Gavva NR, Wen SC, Daftari P, Moniwa M, Yang WM, Yang-Feng LPT, Seto E, Davie JR, Shen CKJ. NAPP2, a peroxisomal membrane protein, is also a transcriptional corepressor. Genomics 2002; 79:423-31. [PMID: 11863372 DOI: 10.1006/geno.2002.6714] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Nuclear factor-erythroid number 2 (NF-E2) is a positive regulatory, DNA binding transcription factor for gene expression in erythroid and megakaryocytic cells. To further understand the mechanisms of NF-E2 function, we used expression cloning to identify coregulators interacting with the erythroid-specific subunit of NF-E2, p45. We have isolated a protein, NAPP2, which contains an aspartic-acid- and glutamic-acid-rich region and a nuclear localization signal. The gene encoding NAPP2, PEX14, is located on chromosome 1p36 and is ubiquitously expressed. The domains of interaction in vitro and in vivo between p45 and NAPP2 were mapped by a yeast two-hybrid system and cotransfection experiments. In mammalian cell culture, ectopically expressed NAPP2 inhibited p45-directed transcriptional activation. Furthermore, NAPP2 functions as a corepressor and interacts specifically with histone deacetylase l (HDAC1), but not HDAC2 or HDAC3. NAPP2 is thus potentially a negative coregulator of NF-E2. NAPP2 is identical to PEX14, an integral membrane protein essential for protein docking onto the peroxisomes. These studies have identified a novel, bifunctional protein capable of acting as a transcriptional corepressor and a polypeptide transport modulator. They also suggest that NF-E2 may function both positively and negatively in the transcription regulation of specific erythroid and megakaryocytic genes.
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Affiliation(s)
- Narender R Gavva
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, Republic of China
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