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Helzer KT, Hooper C, Miyamoto S, Alarid ET. Ubiquitylation of nuclear receptors: new linkages and therapeutic implications. J Mol Endocrinol 2015; 54:R151-67. [PMID: 25943391 PMCID: PMC4457637 DOI: 10.1530/jme-14-0308] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/05/2015] [Indexed: 12/25/2022]
Abstract
The nuclear receptor (NR) superfamily is a group of transcriptional regulators that control multiple aspects of both physiology and pathology and are broadly recognized as viable therapeutic targets. While receptor-modulating drugs have been successful in many cases, the discovery of new drug targets is still an active area of research, because resistance to NR-targeting therapies remains a significant clinical challenge. Many successful targeted therapies have harnessed the control of receptor activity by targeting events within the NR signaling pathway. In this review, we explore the role of NR ubiquitylation and discuss how the expanding roles of ubiquitin could be leveraged to identify additional entry points to control receptor function for future therapeutic development.
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Affiliation(s)
- Kyle T Helzer
- McArdle Laboratory for Cancer ResearchDepartment of Oncology, 6151 Wisconsin Institutes for Medical Research, University of Wisconsin Carbone Cancer Center, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, Wisconsin 53705, USA
| | - Christopher Hooper
- McArdle Laboratory for Cancer ResearchDepartment of Oncology, 6151 Wisconsin Institutes for Medical Research, University of Wisconsin Carbone Cancer Center, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, Wisconsin 53705, USA
| | - Shigeki Miyamoto
- McArdle Laboratory for Cancer ResearchDepartment of Oncology, 6151 Wisconsin Institutes for Medical Research, University of Wisconsin Carbone Cancer Center, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, Wisconsin 53705, USA
| | - Elaine T Alarid
- McArdle Laboratory for Cancer ResearchDepartment of Oncology, 6151 Wisconsin Institutes for Medical Research, University of Wisconsin Carbone Cancer Center, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, Wisconsin 53705, USA
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52
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Yan Q, Bruchez MP. Advances in chemical labeling of proteins in living cells. Cell Tissue Res 2015; 360:179-94. [PMID: 25743694 PMCID: PMC4380784 DOI: 10.1007/s00441-015-2145-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 02/02/2015] [Indexed: 01/07/2023]
Abstract
The pursuit of quantitative biological information via imaging requires robust labeling approaches that can be used in multiple applications and with a variety of detectable colors and properties. In addition to conventional fluorescent proteins, chemists and biologists have come together to provide a range of approaches that combine dye chemistry with the convenience of genetic targeting. This hybrid-tagging approach amalgamates the rational design of properties available through synthetic dye chemistry with the robust biological targeting available with genetic encoding. In this review, we discuss the current range of approaches that have been exploited for dye targeting or for targeting and activation and some of the recent applications that are uniquely permitted by these hybrid-tagging approaches.
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Affiliation(s)
- Qi Yan
- Sharp Edge Laboratories, Inc. Pittsburgh, PA
| | - Marcel P. Bruchez
- Sharp Edge Laboratories, Inc. Pittsburgh, PA
- Molecular Biosensor and Imaging Center, Carnegie Mellon University, Pittsburgh, PA
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, PA
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA
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Winiecka-Klimek M, Szybka M, Rieske P, Piaskowski S, Bienkowski M, Walczak M, Pacholczyk M, Rostkowski M, Zieba J, Banaszczyk M, Hulas-Bigoszewska K, Peciak J, Pawliczak R, Stoczynska-Fidelus E. PIN3 duplication may be partially responsible for TP53 haploinsufficiency. BMC Cancer 2014; 14:669. [PMID: 25223755 PMCID: PMC4176858 DOI: 10.1186/1471-2407-14-669] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 09/11/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Previously we have suggested that cancer cells develop a mechanism(s) which allows for either: silencing of the wild-type TP53 transcription, degradation of the wild-type TP53 mRNA, or selective overproduction of the mutated TP53 mRNA, which is the subject of this article. Sequencing of TP53 on the respective cDNA and DNA templates from tumor samples were found to give discordant results. DNA analysis showed a pattern of heterozygous mutations, whereas the analysis of cDNA demonstrated the mutated template only. We hypothesized that different TP53 gene expression levels of each allele may be caused by the polymorphism within intron 3 (PIN3). The aim of this study was to test if one of the polymorphic variants of PIN3 (A1 or A2) in the heterozygotes is associated with a higher TP53 expression, and therefore, responsible for the haploinsufficiency phenomenon. METHODS 250 tumor samples were tested. To analyze the involvement of PIN3 polymorphic variant (A1 or A2) on TP53 mRNA expression regulation, bacterial subcloning combined with sequencing analyses, dual luciferase reporter assays and bioinformatic analysis were performed. RESULTS Haplotype analysis showed the predominance of the mutated template during the cDNA sequencing in all samples showing a heterozygous TP53 mutation and PIN3 heterozygosity. Out of 30 samples (from the total of 250 tested samples) which carried TP53 mutations and had a bias in allelic expression 6 were heterozygous for the A1/A2 polymorphism, and all 6 (p = 0.04) samples carried the mutation within the PIN3 longer allele (A2). Reporter assays revealed higher luciferase activity in cells transfected with the plasmid containing A2 construct than A1 and control. A2/A1 ratio ranged from 1.16 for AD293 cell line (p = 0.019) to 1.59 for SW962 cell line (p = 0.0019). Moreover, bioinformatic analyses showed that PIN3 duplication stabilized secondary DNA structures - G-quadruplexes. CONCLUSION TP53 alleles are not equivalent for their impact on the regulation of expression of TP53 mRNA. Therefore, in PIN3-heterozygous cases a single TP53 mutation of the longer allele might sufficiently destabilize its function. Secondary DNA structures such as quadruplexes can also play a role in PIN3-dependent TP53 haploinsufficiency.
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Affiliation(s)
- Marta Winiecka-Klimek
- Department of Tumor Biology, Medical University of Lodz, Zeligowskiego 7/9, 90-752, Lodz, Poland.
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Ge W, Li D, Gao Y, Cao X. The Roles of Lysosomes in Inflammation and Autoimmune Diseases. Int Rev Immunol 2014; 34:415-31. [DOI: 10.3109/08830185.2014.936587] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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55
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He Y, Yi W, Suino-Powell K, Zhou XE, Tolbert WD, Tang X, Yang J, Yang H, Shi J, Hou L, Jiang H, Melcher K, Xu HE. Structures and mechanism for the design of highly potent glucocorticoids. Cell Res 2014; 24:713-26. [PMID: 24763108 DOI: 10.1038/cr.2014.52] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Revised: 02/28/2014] [Accepted: 03/12/2014] [Indexed: 02/07/2023] Open
Abstract
The evolution of glucocorticoid drugs was driven by the demand of lowering the unwanted side effects, while keeping the beneficial anti-inflammatory effects. Potency is an important aspect of this evolution as many undesirable side effects are associated with use of high-dose glucocorticoids. The side effects can be minimized by highly potent glucocorticoids that achieve the same treatment effects at lower doses. This demand propelled the continuous development of synthetic glucocorticoids with increased potencies, but the structural basis of their potencies is poorly understood. To determine the mechanisms underlying potency, we solved the X-ray structures of the glucocorticoid receptor (GR) ligand-binding domain (LBD) bound to its endogenous ligand, cortisol, which has relatively low potency, and a highly potent synthetic glucocorticoid, mometasone furoate (MF). The cortisol-bound GR LBD revealed that the flexibility of the C1-C2 single bond in the steroid A ring is primarily responsible for the low affinity of cortisol to GR. In contrast, we demonstrate that the very high potency of MF is achieved by its C-17α furoate group completely filling the ligand-binding pocket, thus providing additional anchor contacts for high-affinity binding. A single amino acid in the ligand-binding pocket, Q642, plays a discriminating role in ligand potency between MF and cortisol. Structure-based design led to synthesis of several novel glucocorticoids with much improved potency and efficacy. Together, these results reveal key structural mechanisms of glucocorticoid potency and provide a rational basis for developing novel highly potent glucocorticoids.
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Affiliation(s)
- Yuanzheng He
- Laboratory of Structural Sciences, Van Andel Research Institute, Grand Rapids, MI 49503, USA
| | - Wei Yi
- VARI-SIMM Center, Center for Structure and Function of Drug Targets, Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Kelly Suino-Powell
- Laboratory of Structural Sciences, Van Andel Research Institute, Grand Rapids, MI 49503, USA
| | - X Edward Zhou
- Laboratory of Structural Sciences, Van Andel Research Institute, Grand Rapids, MI 49503, USA
| | - W David Tolbert
- Laboratory of Structural Sciences, Van Andel Research Institute, Grand Rapids, MI 49503, USA
| | - Xiaobo Tang
- VARI-SIMM Center, Center for Structure and Function of Drug Targets, Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Jing Yang
- Center for Drug Discovery and Design, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Huaiyu Yang
- Center for Drug Discovery and Design, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Jingjing Shi
- VARI-SIMM Center, Center for Structure and Function of Drug Targets, Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Li Hou
- VARI-SIMM Center, Center for Structure and Function of Drug Targets, Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Hualiang Jiang
- Center for Drug Discovery and Design, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Karsten Melcher
- Laboratory of Structural Sciences, Van Andel Research Institute, Grand Rapids, MI 49503, USA
| | - H Eric Xu
- 1] Laboratory of Structural Sciences, Van Andel Research Institute, Grand Rapids, MI 49503, USA [2] VARI-SIMM Center, Center for Structure and Function of Drug Targets, Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
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Totta P, Pesiri V, Marino M, Acconcia F. Lysosomal function is involved in 17β-estradiol-induced estrogen receptor α degradation and cell proliferation. PLoS One 2014; 9:e94880. [PMID: 24736371 PMCID: PMC3988130 DOI: 10.1371/journal.pone.0094880] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 03/18/2014] [Indexed: 11/18/2022] Open
Abstract
The homeostatic control of the cellular proteome steady-state is dependent either on the 26S proteasome activity or on the lysosome function. The sex hormone 17β-estradiol (E2) controls a plethora of biological functions by binding to the estrogen receptor α (ERα), which is both a nuclear ligand-activated transcription factor and also an extrinsic plasma membrane receptor. Regulation of E2-induced physiological functions (e.g., cell proliferation) requires the synergistic activation of both transcription of estrogen responsive element (ERE)-containing genes and rapid extra-nuclear phosphorylation of many different signalling kinases (e.g., ERK/MAPK; PI3K/AKT). Although E2 controls ERα intracellular content and activity via the 26S proteasome-mediated degradation, biochemical and microscopy-based evidence suggests a possible cross-talk among lysosomes and ERα activities. Here, we studied the putative localization of endogenous ERα to lysosomes and the role played by lysosomal function in ERα signalling. By using confocal microscopy and biochemical assays, we report that ERα localizes to lysosomes and to endosomes in an E2-dependent manner. Moreover, the inhibition of lysosomal function obtained by chloroquine demonstrates that, in addition to 26S proteasome-mediated receptor elimination, lysosome-based degradation also contributes to the E2-dependent ERα breakdown. Remarkably, the lysosome function is further involved in those ERα activities required for E2-dependent cell proliferation while it is dispensable for ERα-mediated ERE-containing gene transcription. Our discoveries reveal a novel lysosome-dependent degradation pathway for ERα and show a novel biological mechanism by which E2 regulates ERα cellular content and, as a consequence, cellular functions.
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Affiliation(s)
- Pierangela Totta
- Department of Sciences, Section Biomedical Sciences and Technology, University Roma Tre, Rome, Italy
| | - Valeria Pesiri
- Department of Sciences, Section Biomedical Sciences and Technology, University Roma Tre, Rome, Italy
| | - Maria Marino
- Department of Sciences, Section Biomedical Sciences and Technology, University Roma Tre, Rome, Italy
| | - Filippo Acconcia
- Department of Sciences, Section Biomedical Sciences and Technology, University Roma Tre, Rome, Italy
- * E-mail:
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Wu W, Wang Y, Deng XL, Sun HY, Li GR. Cholesterol down-regulates BK channels stably expressed in HEK 293 cells. PLoS One 2013; 8:e79952. [PMID: 24260325 PMCID: PMC3832390 DOI: 10.1371/journal.pone.0079952] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2013] [Accepted: 09/28/2013] [Indexed: 12/23/2022] Open
Abstract
Cholesterol is one of the major lipid components of the plasma membrane in mammalian cells and is involved in the regulation of a number of ion channels. The present study investigates how large conductance Ca2+-activated K+ (BK) channels are regulated by membrane cholesterol in BK-HEK 293 cells expressing both the α-subunit hKCa1.1 and the auxiliary β1-subunit or in hKCa1.1-HEK 293 cells expressing only the α-subunit hKCa1.1 using approaches of electrophysiology, molecular biology, and immunocytochemistry. Membrane cholesterol was depleted in these cells with methyl-β-cyclodextrin (MβCD), and enriched with cholesterol-saturated MβCD (MβCD-cholesterol) or low-density lipoprotein (LDL). We found that BK current density was decreased by cholesterol enrichment in BK-HEK 293 cells, with a reduced expression of KCa1.1 protein, but not the β1-subunit protein. This effect was fully countered by the proteasome inhibitor lactacystin or the lysosome function inhibitor bafilomycin A1. Interestingly, in hKCa1.1-HEK 293 cells, the current density was not affected by cholesterol enrichment, but directly decreased by MβCD, suggesting that the down-regulation of BK channels by cholesterol depends on the auxiliary β1-subunit. The reduced KCa1.1 channel protein expression was also observed in cultured human coronary artery smooth muscle cells with cholesterol enrichment using MβCD-cholesterol or LDL. These results demonstrate the novel information that cholesterol down-regulates BK channels by reducing KCa1.1 protein expression via increasing the channel protein degradation, and the effect is dependent on the auxiliary β1-subunit.
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Affiliation(s)
- Wei Wu
- Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - Yan Wang
- Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, China
- Department of Physiology and Pathophysiology, School of Medicine, Xi'an Jiaotong University, Xi'an, China
| | - Xiu-Ling Deng
- Department of Physiology and Pathophysiology, School of Medicine, Xi'an Jiaotong University, Xi'an, China
| | - Hai-Ying Sun
- Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - Gui-Rong Li
- Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, China
- Department of Physiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, China
- * E-mail:
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58
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Lewis DJ, Williams TC, Beck SL. Foamy macrophage responses in the rat lung following exposure to inhaled pharmaceuticals: a simple, pragmatic approach for inhaled drug development. J Appl Toxicol 2013; 34:319-31. [DOI: 10.1002/jat.2950] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Revised: 09/18/2013] [Accepted: 09/18/2013] [Indexed: 12/31/2022]
Affiliation(s)
- David J. Lewis
- Safety Assessment, GlaxoSmithKline; Ware Herts SG12 0DP UK
| | | | - Steven L. Beck
- Safety Assessment, GlaxoSmithKline; Ware Herts SG12 0DP UK
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59
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Broekman DC, Guðmundsson GH, Maier VH. Differential regulation of cathelicidin in salmon and cod. FISH & SHELLFISH IMMUNOLOGY 2013; 35:532-538. [PMID: 23727282 DOI: 10.1016/j.fsi.2013.05.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Revised: 04/29/2013] [Accepted: 05/06/2013] [Indexed: 06/02/2023]
Abstract
Antimicrobial peptides (AMPs) are an important component of innate immunity in vertebrates. The cathelicidin family of AMPs is well characterized in mammals and has also been reported in several fish species. In this study we investigated the regulation of cathelicidin expression in a gadoid and a salmonid cell-line in order to dissect the signalling pathways involved. For this, fish cells were treated with microbial lysates, purified microbial components and commercial signalling inhibitors and expression of cathelicidin was assessed with quantitative real-time PCR (qPCR). We found that cathelicidin expression was induced in both cell lines in response to microbial stimuli, but the response patterns differed in these evolutionary distant fish species. Our data suggest that in salmonids, pattern recognition receptors such as TLR5 may be involved in the stimulation of cathelicidin expression and that the signalling cascade can include PI3-kinase and cellular trafficking compartments. A detailed knowledge of the regulating factors involved in AMP-related defence responses, including cathelicidin, could help in developing strategies to enhance the immune defence of fish.
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Affiliation(s)
- Daniela C Broekman
- Institute of Biology, University of Iceland, Sturlagata 7, 101 Reykjavik, Iceland
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60
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Kim SE, Overholtzer M. Autophagy proteins regulate cell engulfment mechanisms that participate in cancer. Semin Cancer Biol 2013; 23:329-36. [PMID: 23726896 DOI: 10.1016/j.semcancer.2013.05.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 05/09/2013] [Accepted: 05/21/2013] [Indexed: 12/21/2022]
Abstract
Recent evidence has uncovered cross-regulation of mechanisms of cell engulfment by proteins of the autophagy pathway, in what is called LC3-Associated Phagocytosis, or LAP. By LAP, lysosome fusion to phagosomes and the degradation of engulfed extracellular cargo are facilitated by autophagy proteins that lipidate LC3 onto phagosome membranes. Here we discuss the contexts where LAP is known to occur by focusing on potential roles in tumorigenesis, including predicted consequences of LAP inhibition.
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Affiliation(s)
- Sung Eun Kim
- BCMB Allied Program, Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065, USA; Cell Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA
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61
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Bhattacharya A, Eissa NT. Autophagy and autoimmunity crosstalks. Front Immunol 2013; 4:88. [PMID: 23596443 PMCID: PMC3625920 DOI: 10.3389/fimmu.2013.00088] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Accepted: 04/01/2013] [Indexed: 01/03/2023] Open
Abstract
Autophagy, initially viewed as a conserved bulk-degradation mechanism, has emerged as a central player in a multitude of immune functions. Autophagy is important in host defense against intracellular and extracellular pathogens, metabolic syndromes, immune cell homeostasis, antigen processing and presentation, and maintenance of tolerance. The observation that the above processes are implicated in triggering or exacerbating autoimmunity raises the possibility that autophagy is involved in mediating autoimmune processes, either directly or as a consequence of innate or adaptive functions mediated by the pathway. Genome-wide association studies have shown association between single nucleotide polymorphisms (SNPs) in autophagy related gene 5 (Atg5), and Atg16l1 with susceptibility to systemic lupus erythematosus (SLE) and Crohn’s disease, respectively. Enhanced expression of Atg5 was also reported in blood of mice with experimental autoimmune encephalomyelitis (EAE), a mouse model of multiple sclerosis (MS), and in T cells isolated from blood or brain tissues from patients with active relapse of MS. This review explores the roles of autophagy pathway in the innate and adaptive immune systems on regulating or mediating the onset, progression, or exacerbation of autoimmune processes.
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62
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Leung KKK, Shilton BH. Chloroquine binding reveals flavin redox switch function of quinone reductase 2. J Biol Chem 2013; 288:11242-51. [PMID: 23471972 DOI: 10.1074/jbc.m113.457002] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Quinone reductase 2 (NQO2) is an FAD-linked enzyme and the only known human target of two antimalarial drugs, primaquine (PQ) and chloroquine (CQ). The structural differences between oxidized and reduced NQO2 and the structural basis for inhibition by PQ and CQ were investigated by x-ray crystallography. Structures of oxidized NQO2 in complex with PQ and CQ were solved at 1.4 Å resolution. CQ binds preferentially to reduced NQO2, and upon reduction of NQO2-CQ crystals, the space group changed from P2(1)2(1)2(1) to P2(1), with 1-Å decreases in all three unit cell dimensions. The change in crystal packing originated in the negative charge and 4-5º bend in the reduced isoalloxazine ring of FAD, which resulted in a new mode of CQ binding and closure of a flexible loop (Phe(126)-Leu(136)) over the active site. This first structure of a reduced quinone reductase shows that reduction of the FAD cofactor and binding of a specific inhibitor lead to global changes in NQO2 structure and is consistent with a functional role for NQO2 as a flavin redox switch.
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Affiliation(s)
- Kevin K K Leung
- Department of Biochemistry, University of Western Ontario, London, Ontario N6A 5C1, Canada
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63
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Urh M, Rosenberg M. HaloTag, a Platform Technology for Protein Analysis. CURRENT CHEMICAL GENOMICS 2012; 6:72-8. [PMID: 23213345 PMCID: PMC3480824 DOI: 10.2174/1875397301206010072] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Revised: 08/03/2012] [Accepted: 08/05/2012] [Indexed: 01/01/2023]
Abstract
Understanding protein function and interaction is central to the elucidation of biological processes. Systematic analysis of protein interactions have shown that the eukaryotic proteome is highly interconnected and that biological function frequently depends on the orchestrated action of many proteins. Perturbation of these functions or interactions can lead to various disease states and pharmacologic intervention can result in corrective therapies. The fact that proteins rarely act in isolation, but rather comprise complex machines that stably and/or transiently interact with many different partners at different times, demands the need for robust tools that allow comprehensive global analyses of these events. Here we describe a powerful protein fusion technology, the HaloTag platform, and how it enables the study of many facets of protein biology by offering a broad choice of applications. We review the development of the key aspects of the technology and it's performance in both in vitro and in vivo applications. In particular, we focus on HaloTag's multifunctional utility in protein imaging, protein isolation and display, and in the study of protein complexes and interactions. We demonstrate it's potential to help elucidate important facets of proteomic biology across complex biological systems at the biochemical, cell-based and whole animal level.
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Gostner JM, Schröcksnadel S, Becker K, Jenny M, Schennach H, Uberall F, Fuchs D. Antimalarial drug chloroquine counteracts activation of indoleamine (2,3)-dioxygenase activity in human PBMC. FEBS Open Bio 2012; 2:241-5. [PMID: 23650606 PMCID: PMC3642164 DOI: 10.1016/j.fob.2012.08.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Revised: 08/08/2012] [Accepted: 08/13/2012] [Indexed: 01/17/2023] Open
Abstract
Antimalarial chloroquine is also used for the treatment of immune-mediated diseases. The interference of chloroquine with interferon-γ-induced tryptophan breakdown and neopterin production has been investigated in human peripheral blood mononuclear cells (PBMC) in vitro. Micromolar concentrations (2–50 μM) of chloroquine dose-dependently suppressed mitogen-induced tryptophan breakdown in PBMC but not in the myelomonocytic THP-1-Blue cell line, after 48 h of treatment. In stimulated PBMC, neopterin production was super-induced by 10 μM chloroquine, while it was significantly suppressed at a concentration of 50 μM. These anti-inflammatory effects may relate to the therapeutic benefit of chloroquine in inflammatory conditions and may widen the spectrum of its clinical applications.
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Affiliation(s)
- Johanna M Gostner
- Division of Medical Biochemistry, Biocenter, Innsbruck Medical University, 6020 Innsbruck, Austria
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Ruppert SM, Li W, Zhang G, Carlson AL, Limaye A, Durum SK, Khaled AR. The major isoforms of Bim contribute to distinct biological activities that govern the processes of autophagy and apoptosis in interleukin-7 dependent lymphocytes. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1823:1877-93. [PMID: 22728771 DOI: 10.1016/j.bbamcr.2012.06.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2011] [Revised: 06/01/2012] [Accepted: 06/14/2012] [Indexed: 12/22/2022]
Abstract
Bim is a BH3-only member of the Bcl-2 family that enables the death of T-cells. Partial rescue of cytokine-deprived T-cells occurs when Bim and the receptor for the T-cell growth factor, interleukin-7, are deleted, implicating Bim as a possible target of interleukin-7-mediated signaling. Alternative splicing yields three major isoforms: BimEL, BimL and BimS. To study the effect of Bim deficiency and define the function of the major isoforms, Bim-containing and Bim-deficient T-cells, dependent on interleukin-7 for growth, were used. Loss of total Bim in interleukin-7-deprived T-cells resulted in delayed apoptosis. However, loss of Bim also impeded the later degradative phase of autophagy. p62, an autophagy-adaptor protein which is normally degraded, accumulated in Bim deficient cells. To explain this, BimL was found to support acidification of lysosomes that later may associate with autophagic vesicles. Key findings showed that inhibition of lysosomal acidification accelerated death upon interleukin-7 withdrawal only in Bim-containing T-cells. intereukin-7 dependent T-cells lacking Bim were less sensitive to inhibition of lysosomal acidification. BimL co-immunoprecipitated with dynein and Lamp1-containing vesicles, indicating BimL could be an adaptor for dynein to facilitate loading of lysosomes. In Bim deficient T-cells, lysosome-tracking probes revealed vesicles of less acidic pH. Over-expression of BimL restored acidic vesicles in Bim deficient T-cells, while other isoforms, BimEL and BimS, promoted intrinsic cell death. These results reveal a novel role for BimL in lysosomal positioning that may be required for the formation of degradative autolysosomes.
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Affiliation(s)
- Shannon M Ruppert
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32827, USA
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Shrivastava A, Khanna D. Antimalarials: Reversing the autoimmune “mal-area”? INDIAN JOURNAL OF RHEUMATOLOGY 2012. [DOI: 10.1016/j.injr.2012.04.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Al-Bari MAA, Shinohara M, Nagai Y, Takayanagi H. Inhibitory effect of chloroquine on bone resorption reveals the key role of lysosomes in osteoclast differentiation and function. Inflamm Regen 2012. [DOI: 10.2492/inflammregen.32.222] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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He Y, VanHook AM. Science Signaling
Podcast: 5 July 2011. Sci Signal 2011. [DOI: 10.1126/scisignal.2002276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The anti-inflammatory effects of chloroquine are mediated by inhibition of the lysosome, which enhances glucocorticoid signaling.
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Affiliation(s)
- Yuanzheng He
- Laboratory of Structural Sciences, Van Andel Research Institute, 333 Bostwick Avenue, NE, Grand Rapids, MI 49503, USA
| | - Annalisa M. VanHook
- Web Editor, Science Signaling, American Association for the Advancement of Science, 1200 New York Avenue, NW, Washington, DC 20005, USA
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