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Leclerc NR, Dunne TM, Shrestha S, Johnson CP, Kelley JB. TOR signaling regulates GPCR levels on the plasma membrane and suppresses the Saccharomyces cerevisiae mating pathway. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.09.593412. [PMID: 38798445 PMCID: PMC11118302 DOI: 10.1101/2024.05.09.593412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Saccharomyces cerevisiae respond to mating pheromone through the GPCRs Ste2 and Ste3, which promote growth of a mating projection in response to ligand binding. This commitment to mating is nutritionally and energetically taxing, and so we hypothesized that the cell may suppress mating signaling during starvation. We set out to investigate negative regulators of the mating pathway in nutritionally depleted environments. Here, we report that nutrient deprivation led to loss of Ste2 from the plasma membrane. Recapitulating this effect with nitrogen starvation led us to hypothesize that it was due to TORC1 signaling. Rapamycin inhibition of TORC1 impacted membrane levels of all yeast GPCRs. Inhibition of TORC1 also dampened mating pathway output. Deletion analysis revealed that TORC1 repression leads to α-arrestin-directed CME through TORC2-Ypk1 signaling. We then set out to determine whether major downstream effectors of the TOR complexes also downregulate pathway output during mating. We found that autophagy contributes to pathway downregulation through analysis of strains lacking ATG8 . We also show that Ypk1 significantly reduced pathway output. Thus, both autophagy machinery and TORC2-Ypk1 signaling serve as attenuators of pheromone signaling during mating. Altogether, we demonstrate that the stress-responsive TOR complexes coordinate GPCR endocytosis and reduce the magnitude of pheromone signaling, in ligand-independent and ligand-dependent contexts. One Sentence Summary TOR signaling regulates the localization of all Saccharomyces cerevisiae GPCRs during starvation and suppress the mating pathway in the presence and absence of ligand.
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Maaliki D, Jaffa AA, Nasser S, Sahebkar A, Eid AH. Adrenoceptor Desensitization: Current Understanding of Mechanisms. Pharmacol Rev 2024; 76:358-387. [PMID: 38697858 DOI: 10.1124/pharmrev.123.000831] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 01/15/2024] [Accepted: 01/18/2024] [Indexed: 05/05/2024] Open
Abstract
G-protein coupled receptors (GPCRs) transduce a wide range of extracellular signals. They are key players in the majority of biologic functions including vision, olfaction, chemotaxis, and immunity. However, as essential as most of them are to body function and homeostasis, overactivation of GPCRs has been implicated in many pathologic diseases such as cancer, asthma, and heart failure (HF). Therefore, an important feature of G protein signaling systems is the ability to control GPCR responsiveness, and one key process to control overstimulation involves initiating receptor desensitization. A number of steps are appreciated in the desensitization process, including cell surface receptor phosphorylation, internalization, and downregulation. Rapid or short-term desensitization occurs within minutes and involves receptor phosphorylation via the action of intracellular protein kinases, the binding of β-arrestins, and the consequent uncoupling of GPCRs from their cognate heterotrimeric G proteins. On the other hand, long-term desensitization occurs over hours to days and involves receptor downregulation or a decrease in cell surface receptor protein level. Of the proteins involved in this biologic phenomenon, β-arrestins play a particularly significant role in both short- and long-term desensitization mechanisms. In addition, β-arrestins are involved in the phenomenon of biased agonism, where the biased ligand preferentially activates one of several downstream signaling pathways, leading to altered cellular responses. In this context, this review discusses the different patterns of desensitization of the α 1-, α 2- and the β adrenoceptors and highlights the role of β-arrestins in regulating physiologic responsiveness through desensitization and biased agonism. SIGNIFICANCE STATEMENT: A sophisticated network of proteins orchestrates the molecular regulation of GPCR activity. Adrenoceptors are GPCRs that play vast roles in many physiological processes. Without tightly controlled desensitization of these receptors, homeostatic imbalance may ensue, thus precipitating various diseases. Here, we critically appraise the mechanisms implicated in adrenoceptor desensitization. A better understanding of these mechanisms helps identify new druggable targets within the GPCR desensitization machinery and opens exciting therapeutic fronts in the treatment of several pathologies.
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Affiliation(s)
- Dina Maaliki
- Department of Pharmacology and Toxicology, American University of Beirut, Beirut, Lebanon (D.M.); School of Medicine, University of South Carolina, Columbia, South Carolina (A.A.J.); Keele University, Staffordshire, United Kingdom (S.N.); Applied Biomedical Research Center, Mashhad University of Medical Sciences, Mashhad, Iran (A.S.); Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran (A.S.); and Department of Basic Medical Sciences, College of Medicine, QU Health, Qatar University, Doha, Qatar (A.H.E.)
| | - Aneese A Jaffa
- Department of Pharmacology and Toxicology, American University of Beirut, Beirut, Lebanon (D.M.); School of Medicine, University of South Carolina, Columbia, South Carolina (A.A.J.); Keele University, Staffordshire, United Kingdom (S.N.); Applied Biomedical Research Center, Mashhad University of Medical Sciences, Mashhad, Iran (A.S.); Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran (A.S.); and Department of Basic Medical Sciences, College of Medicine, QU Health, Qatar University, Doha, Qatar (A.H.E.)
| | - Suzanne Nasser
- Department of Pharmacology and Toxicology, American University of Beirut, Beirut, Lebanon (D.M.); School of Medicine, University of South Carolina, Columbia, South Carolina (A.A.J.); Keele University, Staffordshire, United Kingdom (S.N.); Applied Biomedical Research Center, Mashhad University of Medical Sciences, Mashhad, Iran (A.S.); Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran (A.S.); and Department of Basic Medical Sciences, College of Medicine, QU Health, Qatar University, Doha, Qatar (A.H.E.)
| | - Amirhossein Sahebkar
- Department of Pharmacology and Toxicology, American University of Beirut, Beirut, Lebanon (D.M.); School of Medicine, University of South Carolina, Columbia, South Carolina (A.A.J.); Keele University, Staffordshire, United Kingdom (S.N.); Applied Biomedical Research Center, Mashhad University of Medical Sciences, Mashhad, Iran (A.S.); Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran (A.S.); and Department of Basic Medical Sciences, College of Medicine, QU Health, Qatar University, Doha, Qatar (A.H.E.)
| | - Ali H Eid
- Department of Pharmacology and Toxicology, American University of Beirut, Beirut, Lebanon (D.M.); School of Medicine, University of South Carolina, Columbia, South Carolina (A.A.J.); Keele University, Staffordshire, United Kingdom (S.N.); Applied Biomedical Research Center, Mashhad University of Medical Sciences, Mashhad, Iran (A.S.); Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran (A.S.); and Department of Basic Medical Sciences, College of Medicine, QU Health, Qatar University, Doha, Qatar (A.H.E.)
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Zhang F, Liu C, Chen Z, Zhao C. A novel PDIA3/FTO/USP20 positive feedback regulatory loop induces osteogenic differentiation of preosteoblast in osteoporosis. Cell Biol Int 2024; 48:541-550. [PMID: 38321831 DOI: 10.1002/cbin.12134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 12/05/2023] [Accepted: 01/01/2024] [Indexed: 02/08/2024]
Abstract
Osteoporosis is a chronic skeletal disease and the major source of risk for fractures in aged people. It is urgent to investigate the mechanism regulating osteoporosis for developing potential treatment and prevention strategies. Osteogenic differentiation of preosteoblast enhances bone formation, which might be a promising strategy for treatment and prevention of osteoporosis. Protein disulfide isomerase family A, member 3 (PDIA3) could induce bone formation, yet the role of PDIA3 in osteogenic differentiation of preosteoblast remains unknown. In this study, m6 A RNA methylation was detected by methylated RNA immunoprecipitation (MeRIP), while mRNA stability was identified by RNA decay assay. Besides, protein-protein interaction and protein phosphorylation were determined using co-immunoprecipitation (Co-IP). Herein, results revealed that PDIA3 promoted osteogenic differentiation of preosteoblast MC3T3-E1. Besides, PDIA3 mRNA methylation was suppressed by FTO alpha-ketoglutarate dependent dioxygenase (FTO) as RNA methylation reduced PDIA3 mRNA stability during osteogenic differentiation of MC3T3-E1 cells. Moreover, ubiquitin specific peptidase 20 (USP20) improved FTO level through inhibiting FTO degradation while PDIA3 increased FTO level by enhancing USP20 phosphorylation during osteogenic differentiation of MC3T3-E1 cells, suggesting a positive feedback regulatory loop between PDIA3 and FTO. In summary, these findings indicated the mechanism of PDIA3 regulating osteogenic differentiation of preosteoblast and provided potential therapeutic targets for osteoporosis.
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Affiliation(s)
- Fei Zhang
- First Department of Orthopaedics, Zhongshan City People's Hospital, Zhongshan, Guangdong, China
| | - Chen Liu
- Surgery Department, Zhongshan Port Hospital, Zhongshan, Guangdong, China
| | - Zhiyong Chen
- Department of Neurosurgery, The Affiliated Hospital of Jinan University, Guangzhou, China
- Minimally Invasive Treatment Center for Pituitary Adenoma of Jinan University, Guangzhou, China
| | - Chengyi Zhao
- Second Department of Orthopaedics, Zhongshan City People's Hospital, Zhongshan, Guangdong, China
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Zhang L, Wu JH, Jean-Charles PY, Murali P, Zhang W, Jazic A, Kaur S, Nepliouev I, Stiber JA, Snow K, Freedman NJ, Shenoy SK. Phosphorylation of USP20 on Ser334 by IRAK1 promotes IL-1β-evoked signaling in vascular smooth muscle cells and vascular inflammation. J Biol Chem 2023; 299:104911. [PMID: 37311534 PMCID: PMC10362797 DOI: 10.1016/j.jbc.2023.104911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 05/11/2023] [Accepted: 06/05/2023] [Indexed: 06/15/2023] Open
Abstract
Reversible lysine-63 (K63) polyubiquitination regulates proinflammatory signaling in vascular smooth muscle cells (SMCs) and plays an integral role in atherosclerosis. Ubiquitin-specific peptidase 20 (USP20) reduces NFκB activation triggered by proinflammatory stimuli, and USP20 activity attenuates atherosclerosis in mice. The association of USP20 with its substrates triggers deubiquitinase activity; this association is regulated by phosphorylation of USP20 on Ser334 (mouse) or Ser333 (human). USP20 Ser333 phosphorylation was greater in SMCs of atherosclerotic segments of human arteries as compared with nonatherosclerotic segments. To determine whether USP20 Ser334 phosphorylation regulates proinflammatory signaling, we created USP20-S334A mice using CRISPR/Cas9-mediated gene editing. USP20-S334A mice developed ∼50% less neointimal hyperplasia than congenic WT mice after carotid endothelial denudation. WT carotid SMCs showed substantial phosphorylation of USP20 Ser334, and WT carotids demonstrated greater NFκB activation, VCAM-1 expression, and SMC proliferation than USP20-S334A carotids. Concordantly, USP20-S334A primary SMCs in vitro proliferated and migrated less than WT SMCs in response to IL-1β. An active site ubiquitin probe bound to USP20-S334A and USP20-WT equivalently, but USP20-S334A associated more avidly with TRAF6 than USP20-WT. IL-1β induced less K63-linked polyubiquitination of TRAF6 and less downstream NFκB activity in USP20-S334A than in WT SMCs. Using in vitro phosphorylation with purified IRAK1 and siRNA-mediated gene silencing of IRAK1 in SMCs, we identified IRAK1 as a novel kinase for IL-1β-induced USP20 Ser334 phosphorylation. Our findings reveal novel mechanisms regulating IL-1β-induced proinflammatory signaling: by phosphorylating USP20 Ser334, IRAK1 diminishes the association of USP20 with TRAF6 and thus augments NFκB activation, SMC inflammation, and neointimal hyperplasia.
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Affiliation(s)
- Lisheng Zhang
- Department of Medicine (Cardiology), Duke University Medical Center, Durham, North Carolina, USA
| | - Jiao-Hui Wu
- Department of Medicine (Cardiology), Duke University Medical Center, Durham, North Carolina, USA
| | - Pierre-Yves Jean-Charles
- Department of Medicine (Cardiology), Duke University Medical Center, Durham, North Carolina, USA
| | - Pavitra Murali
- Department of Medicine (Cardiology), Duke University Medical Center, Durham, North Carolina, USA
| | - Wenli Zhang
- Department of Medicine (Cardiology), Duke University Medical Center, Durham, North Carolina, USA
| | - Aeva Jazic
- Department of Medicine (Cardiology), Duke University Medical Center, Durham, North Carolina, USA
| | - Suneet Kaur
- Department of Medicine (Cardiology), Duke University Medical Center, Durham, North Carolina, USA
| | - Igor Nepliouev
- Department of Medicine (Cardiology), Duke University Medical Center, Durham, North Carolina, USA
| | - Jonathan A Stiber
- Department of Medicine (Cardiology), Duke University Medical Center, Durham, North Carolina, USA
| | - Kamie Snow
- Department of Medicine (Cardiology), Duke University Medical Center, Durham, North Carolina, USA
| | - Neil J Freedman
- Department of Medicine (Cardiology), Duke University Medical Center, Durham, North Carolina, USA; Department of Cell Biology, Duke University Medical Center, Durham, North Carolina, USA.
| | - Sudha K Shenoy
- Department of Medicine (Cardiology), Duke University Medical Center, Durham, North Carolina, USA; Department of Cell Biology, Duke University Medical Center, Durham, North Carolina, USA.
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Kaur S, Sokrat B, Capozzi ME, El K, Bai Y, Jazic A, Han B, Krishnakumar K, D'Alessio DA, Campbell JE, Bouvier M, Shenoy SK. The Ubiquitination Status of the Glucagon Receptor determines Signal Bias. J Biol Chem 2023; 299:104690. [PMID: 37037304 DOI: 10.1016/j.jbc.2023.104690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 03/03/2023] [Accepted: 03/31/2023] [Indexed: 04/12/2023] Open
Abstract
The pancreatic hormone glucagon activates the glucagon receptor (GCGR), a class B seven-transmembrane G protein-coupled receptor (GPCR) that couples to the stimulatory heterotrimeric Gs protein and provokes protein kinase A-dependent signaling cascades vital to hepatic glucose metabolism and islet insulin secretion. Glucagon-stimulation also initiates recruitment of the endocytic adaptors, β-arrestin1 and β-arrestin2, which regulate desensitization and internalization of the GCGR. Unlike many other GPCRs, the GCGR expressed at the plasma membrane is constitutively ubiquitinated and upon agonist-activation, internalized GCGRs are deubiquitinated at early endosomes and recycled via Rab4-containing vesicles. Herein we report a novel link between the ubiquitination status and signal transduction mechanism of the GCGR. In the deubiquitinated state, coupling of the GCGR to Gs is diminished, while binding to β-arrestin is enhanced with signaling biased to a β-arrestin1-dependent p38 mitogen activated protein kinase (MAPK) pathway. This ubiquitin-dependent signaling bias arises through the modification of lysine333 (K333) on the cytoplasmic face of transmembrane helix V. Compared with the GCGR-WT, the mutant GCGR-K333R has impaired ubiquitination, diminished G protein coupling and protein kinase A signaling, but unimpaired potentiation of glucose-stimulated-insulin secretion in response to agonist-stimulation, which involves p38 MAPK signaling. Both WT and GCGR-K333R promote the formation of glucagon-induced β-arrestin1-dependent p38 signaling scaffold that requires canonical upstream MAPK-Kinase3, but is independent of Gs, Gi and β-arrestin2. Thus ubiquitination/deubiquitination at K333 in the GCGR defines the activation of distinct transducers with the potential to influence various facets of glucagon signaling in health and disease.
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Affiliation(s)
- Suneet Kaur
- Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
| | - Badr Sokrat
- Department of Biochemistry and Molecular Medicine, University of Montreal, Montreal, Quebec, H3T 1J4 Canada; Institute for Research in Immunology and Cancer, University of Montreal, Montreal, Quebec, H3T 1J4 Canada
| | - Megan E Capozzi
- Division of Endocrinology, Department of Medicine, Duke Molecular Physiology Institute, Duke University, Durham, NC 27710, USA
| | - Kimberley El
- Division of Endocrinology, Department of Medicine, Duke Molecular Physiology Institute, Duke University, Durham, NC 27710, USA
| | - Yushi Bai
- Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
| | - Aeva Jazic
- Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
| | - Bridgette Han
- Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
| | - Kaavya Krishnakumar
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford CA 94305
| | - David A D'Alessio
- Division of Endocrinology, Department of Medicine, Duke Molecular Physiology Institute, Duke University, Durham, NC 27710, USA
| | - Jonathan E Campbell
- Division of Endocrinology, Department of Medicine, Duke Molecular Physiology Institute, Duke University, Durham, NC 27710, USA
| | - Michel Bouvier
- Department of Biochemistry and Molecular Medicine, University of Montreal, Montreal, Quebec, H3T 1J4 Canada; Institute for Research in Immunology and Cancer, University of Montreal, Montreal, Quebec, H3T 1J4 Canada
| | - Sudha K Shenoy
- Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA; Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA.
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Qin B, Zhou L, Wang F, Wang Y. Ubiquitin-specific protease 20 in human disease: emerging role and therapeutic implications. Biochem Pharmacol 2022; 206:115352. [DOI: 10.1016/j.bcp.2022.115352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Revised: 11/06/2022] [Accepted: 11/15/2022] [Indexed: 11/23/2022]
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The emerging role of ubiquitin-specific protease 20 in tumorigenesis and cancer therapeutics. Cell Death Dis 2022; 13:434. [PMID: 35508480 PMCID: PMC9068925 DOI: 10.1038/s41419-022-04853-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 04/02/2022] [Accepted: 04/12/2022] [Indexed: 12/13/2022]
Abstract
As a critical member of the ubiquitin-specific proteolytic enzyme family, ubiquitin-specific peptidase 20 (USP20) regulates the stability of proteins via multiple signaling pathways. In addition, USP20 upregulation is associated with various cellular biological processes, such as cell cycle progression, proliferation, migration, and invasion. Emerging studies have revealed the pivotal role of USP20 in the tumorigenesis of various cancer types, such as breast cancer, colon cancer, lung cancer, gastric cancer and adult T cell leukemia. In our review, we highlight the different mechanisms of USP20 in various tumor types and demonstrate that USP20 regulates the stability of multiple proteins. Therefore, regulating the activity of USP20 is a novel tumor treatment. However, the clinical significance of USP20 in cancer treatment merits more evidence. Finally, different prospects exist for the continued research focus of USP20.
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Jean-Charles PY, Rajiv V, Sarker S, Han S, Bai Y, Masoudi A, Shenoy SK. A single phenylalanine residue in β-arrestin2 critically regulates its binding to G protein-coupled receptors. J Biol Chem 2022; 298:101837. [PMID: 35307348 PMCID: PMC9052155 DOI: 10.1016/j.jbc.2022.101837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 03/07/2022] [Accepted: 03/08/2022] [Indexed: 12/05/2022] Open
Abstract
Arrestins and their yeast homologs, arrestin-related trafficking adaptors (ARTs), share a stretch of 29 amino acids called the ART motif. However, the functionality of that motif is unknown. We now report that deleting this motif prevents agonist-induced ubiquitination of β-arrestin2 (β-arr2) and blocks its association with activated G protein–coupled receptors (GPCRs). Within the ART motif, we have identified a conserved phenylalanine residue, Phe116, that is critical for the formation of β-arr2–GPCR complexes. β-arr2 Phe116Ala mutant has negligible effect on blunting β2-adrenergic receptor–induced cAMP generation unlike β-arr2, which promotes rapid desensitization. Furthermore, available structures for inactive and inositol hexakisphosphate 6–activated forms of bovine β-arr2 revealed that Phe116 is ensconced in a hydrophobic pocket, whereas the adjacent Phe117 and Phe118 residues are not. Mutagenesis of Phe117 and Phe118, but not Phe116, preserves GPCR interaction of β-arr2. Surprisingly, Phe116 is dispensable for the association of β-arr2 with its non-GPCR partners. β-arr2 Phe116Ala mutant presents a significantly reduced protein half-life compared with β-arr2 and undergoes constitutive Lys-48-linked polyubiquitination, which tags proteins for proteasomal degradation. We also found that Phe116 is critical for agonist-dependent β-arr2 ubiquitination with Lys-63-polyubiquitin linkages that are known mediators of protein scaffolding and signal transduction. Finally, we have shown that β-arr2 Phe116Ala interaction with activated β2-adrenergic receptor can be rescued with an in-frame fusion of ubiquitin. Taken together, we conclude that Phe116 preserves structural stability of β-arr2, regulates the formation of β-arr2–GPCR complexes that inhibit G protein signaling, and promotes subsequent ubiquitin-dependent β-arr2 localization and trafficking.
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Affiliation(s)
- Pierre-Yves Jean-Charles
- Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, North Carolina, USA
| | - Vishwaesh Rajiv
- Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, North Carolina, USA
| | - Subhodeep Sarker
- Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, North Carolina, USA
| | - Sangoh Han
- Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, North Carolina, USA
| | - Yushi Bai
- Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, North Carolina, USA
| | - Ali Masoudi
- Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, North Carolina, USA
| | - Sudha K Shenoy
- Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, North Carolina, USA; Department of Cell Biology, Duke University Medical Center, Durham, North Carolina, USA.
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Tyagi A, Haq S, Ramakrishna S. Redox regulation of DUBs and its therapeutic implications in cancer. Redox Biol 2021; 48:102194. [PMID: 34814083 PMCID: PMC8608616 DOI: 10.1016/j.redox.2021.102194] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 11/19/2021] [Indexed: 02/06/2023] Open
Abstract
Reactive oxygen species (ROS) act as a double-edged sword in cancer, where low levels of ROS are beneficial but excessive accumulation leads to cancer progression. Elevated levels of ROS in cancer are counteracted by the antioxidant defense system. An imbalance between ROS generation and the antioxidant system alters gene expression and cellular signaling, leading to cancer progression or death. Post-translational modifications, such as ubiquitination, phosphorylation, and SUMOylation, play a critical role in the maintenance of ROS homeostasis by controlling ROS production and clearance. Recent evidence suggests that deubiquitinating enzymes (DUBs)-mediated ubiquitin removal from substrates is regulated by ROS. ROS-mediated oxidation of the catalytic cysteine (Cys) of DUBs, leading to their reversible inactivation, has emerged as a key mechanism regulating DUB-controlled cellular events. A better understanding of the mechanism by which DUBs are susceptible to ROS and exploring the ways to utilize ROS to pharmacologically modulate DUB-mediated signaling pathways might provide new insight for anticancer therapeutics. This review assesses the recent findings regarding ROS-mediated signaling in cancers, emphasizes DUB regulation by oxidation, highlights the relevant recent findings, and proposes directions of future research based on the ROS-induced modifications of DUB activity.
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Affiliation(s)
- Apoorvi Tyagi
- Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul, 04763, South Korea
| | - Saba Haq
- Department of Life Science, College of Natural Sciences, Hanyang University, Seoul, 04763, South Korea
| | - Suresh Ramakrishna
- Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul, 04763, South Korea; College of Medicine, Hanyang University, Seoul, 04763, South Korea.
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Li H, Wang F, Guo X, Jiang Y. Decreased MEF2A Expression Regulated by Its Enhancer Methylation Inhibits Autophagy and May Play an Important Role in the Progression of Alzheimer's Disease. Front Neurosci 2021; 15:682247. [PMID: 34220439 PMCID: PMC8242211 DOI: 10.3389/fnins.2021.682247] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 05/12/2021] [Indexed: 12/29/2022] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease characterized by amyloid plaques and neurofibrillary tangles which significantly affects people's life quality. Recently, AD has been found to be closely related to autophagy. The aim of this study was to identify autophagy-related genes associated with the pathogenesis of AD from multiple types of microarray and sequencing datasets using bioinformatics methods and to investigate their role in the pathogenesis of AD in order to identify novel strategies to prevent and treat AD. Our results showed that the autophagy-related genes were significantly downregulated in AD and correlated with the pathological progression. Furthermore, enrichment analysis showed that these autophagy-related genes were regulated by the transcription factor myocyte enhancer factor 2A (MEF2A), which had been confirmed using si-MEF2A. Moreover, the single-cell sequencing data suggested that MEF2A was highly expressed in microglia. Methylation microarray analysis showed that the methylation level of the enhancer region of MEF2A in AD was significantly increased. In conclusion, our results suggest that AD related to the increased methylation level of MEF2A enhancer reduces the expression of MEF2A and downregulates the expression of autophagy-related genes which are closely associated with AD pathogenesis, thereby inhibiting autophagy.
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Affiliation(s)
- Hui Li
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, China
| | - Feng Wang
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, China
| | - Xuqi Guo
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, China
| | - Yugang Jiang
- Tianjin Institute of Environmental and Operational Medicine, Tianjin, China
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Expression, purification and characterization of the second DUSP domain of deubiquitinase USP20/VDU2. Protein Expr Purif 2021; 181:105836. [PMID: 33529762 DOI: 10.1016/j.pep.2021.105836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 01/18/2021] [Accepted: 01/27/2021] [Indexed: 11/22/2022]
Abstract
Deubiquitinase USP20/VDU2 (VHL-interacting Deubiquitinating Enzyme 2) has been proved to play vital roles in multiple cellular processes by controlling the life-span of substrate proteins including hypoxia-inducible factor HIF1α, β2-adrenergic receptor, and type 2 iodothyronine deiodinase etc. USP20 contains four distinct structural domains, which include the N-terminal zinc-finger ubiquitin binding domain (ZnF-UBP), the catalytic domain (USP domain), and two tandem DUSP domains (DUSP1 and DUSP2). Here in this study, we report the setting up of the production approach for USP20 DUSP2, and the NMR characterization of the produced target protein. With the assistance of GB1 tag and glycerol, both the solubility and stability of USP20 DUSP2 are significantly enhanced. And by using the optimized protein production procedure, monomeric and stable 15N, 13C-labeled USP20 DUSP2 sample for NMR data acquisition was obtained. The secondary structural elements of USP20 DUSP2 were then revealed by the analysis of recorded NMR spectra, and USP20 DUSP2 forms an AB3 fold in solution. The production protocol and NMR characterization results reported in this manuscript could be utilized in the extended structural and functional studies of USP20 DUSP2.
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12
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Yang Y, Ding Y, Zhou C, Wen Y, Zhang N. Structural and functional studies of USP20 ZnF-UBP domain by NMR. Protein Sci 2019; 28:1606-1619. [PMID: 31278784 DOI: 10.1002/pro.3675] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 06/30/2019] [Accepted: 07/01/2019] [Indexed: 12/19/2022]
Abstract
Deubiquitinase USP20/VDU2 has been demonstrated to play important roles in multiple cellular processes by controlling the life span of substrate proteins including hypoxia-inducible factor HIF1α, and so forth. USP20 contains four distinct structural domains including the N-terminal zinc-finger ubiquitin binding domain (ZnF-UBP), the catalytic domain (USP domain), and two tandem DUSP domains, and none of the structures for these four domains has been solved. Meanwhile, except for the ZnF-UBP domain, the biological functions for USP20's catalytic domain and tandem DUSP domains have been at least partially clarified. Here in this study, we determined the solution structure of USP20 ZnF-UBP domain and investigated its binding properties with mono-ubiquitin and poly-ubiquitin (K48-linked di-ubiquitin) by using NMR and molecular modeling techniques. USP20's ZnF-UBP domain forms a spherically shaped fold consisting of a central β-sheet with either one α-helix or two α-helices packed on each side of the sheet. However, although having formed a canonical core structure essential for ubiquitin recognition, USP20 ZnF-UBP presents weak ubiquitin binding capacity. The structural basis for understanding USP20 ZnF-UBP's ubiquitin binding capacity was revealed by NMR data-driven docking. Although the electrostatic interactions between D264 of USP5 (E87 in USP20 ZnF-UBP) and R74 of ubiquitin are kept, the loss of the extensive interactions formed between ubiquitin's di-glycine motif and the conserved and non-conserved residues of USP20 ZnF-UBP domain (W41, E55, and Y84) causes a significant decrease in its binding affinity to ubiquitin. Our findings indicate that USP20 ZnF-UBP domain might have a physiological role unrelated to its ubiquitin binding capacity.
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Affiliation(s)
- Yuanyuan Yang
- Department of Analytical Chemistry, Shanghai Institute of Materia Medica Chinese Academy of Sciences, Shanghai, China.,University of the Chinese Academy of Sciences, Beijing, China
| | - Yiluan Ding
- Department of Analytical Chemistry, Shanghai Institute of Materia Medica Chinese Academy of Sciences, Shanghai, China
| | - Chen Zhou
- Department of Analytical Chemistry, Shanghai Institute of Materia Medica Chinese Academy of Sciences, Shanghai, China
| | - Yi Wen
- Oxford Instruments Technology (Shanghai) Co., Ltd, Shanghai, China
| | - Naixia Zhang
- Department of Analytical Chemistry, Shanghai Institute of Materia Medica Chinese Academy of Sciences, Shanghai, China.,University of the Chinese Academy of Sciences, Beijing, China
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13
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Jean-Charles PY, Wu JH, Zhang L, Kaur S, Nepliouev I, Stiber JA, Brian L, Qi R, Wertman V, Shenoy SK, Freedman NJ. USP20 (Ubiquitin-Specific Protease 20) Inhibits TNF (Tumor Necrosis Factor)-Triggered Smooth Muscle Cell Inflammation and Attenuates Atherosclerosis. Arterioscler Thromb Vasc Biol 2019; 38:2295-2305. [PMID: 30354204 DOI: 10.1161/atvbaha.118.311071] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Objective- Signaling that activates NFκB (nuclear factor κB) in smooth muscle cells (SMCs) is integral to atherosclerosis and involves reversible ubiquitination that activates proteins downstream of proatherogenic receptors. Deubiquitination of these proteins is mediated by USP20 (ubiquitin-specific protease 20), among other deubiquitinases. We sought to determine whether USP20 activity in SMCs decreases atherosclerosis. Approach and Results- To address this question, we used male Ldlr-/- mice without (control) or with SMC-specific expression of murine USP20 (SMC-USP20-transgenic) or its dominant-negative (DN; C154S/H643Q) mutant (SMC-DN-USP20-transgenic). Before the appearance of intimal macrophages, NFκB activation in aortic medial SMCs was greater in SMC-DN-USP20-transgenic than in control mice. After 16 weeks on a Western diet, SMC-DN-USP20-transgenic mice had 46% greater brachiocephalic artery atheroma area than control mice. Congruently, aortic atherosclerosis assessed en face was 21% greater than control in SMC-DN-USP20-transgenic mice and 13% less than control in SMC-USP20-transgenic mice. In response to TNF (tumor necrosis factor), SMCs from SMC-DN-USP20-transgenic mice showed ≈3-fold greater NFκB activation than control SMCs. Silencing USP20 in SMCs with siRNA (small interfering RNA) augmented NFκB activation by ≈50% in response to either TNF or IL-1β (interleukin-1β). Coimmunoprecipitation experiments revealed that USP20 associates with several components of the TNFR1 (TNF receptor-1) signaling pathway, including RIPK1 (receptor-interacting protein kinase 1), a critical checkpoint in TNF-induced NFκB activation and inflammation. TNF evoked ≈2-fold more RIPK1 ubiquitination in SMC-DN-USP20-transgenic than in control SMCs, and RIPK1 was deubiquitinated by purified USP20 in vitro. Conclusions- USP20 attenuates TNF- and IL-1β-evoked atherogenic signaling in SMCs, by deubiquitinating RIPK1, among other signaling intermediates.
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Affiliation(s)
- Pierre-Yves Jean-Charles
- From the Departments of Medicine (Cardiology) (P.-Y.J.-C., J.-H.W., L.Z., S.K., I.N., J.A.S., L.B., R.Q., V.W., S.K.S., N.J.F.), Duke University Medical Center, Durham, NC
| | - Jiao-Hui Wu
- From the Departments of Medicine (Cardiology) (P.-Y.J.-C., J.-H.W., L.Z., S.K., I.N., J.A.S., L.B., R.Q., V.W., S.K.S., N.J.F.), Duke University Medical Center, Durham, NC
| | - Lisheng Zhang
- From the Departments of Medicine (Cardiology) (P.-Y.J.-C., J.-H.W., L.Z., S.K., I.N., J.A.S., L.B., R.Q., V.W., S.K.S., N.J.F.), Duke University Medical Center, Durham, NC
| | - Suneet Kaur
- From the Departments of Medicine (Cardiology) (P.-Y.J.-C., J.-H.W., L.Z., S.K., I.N., J.A.S., L.B., R.Q., V.W., S.K.S., N.J.F.), Duke University Medical Center, Durham, NC
| | - Igor Nepliouev
- From the Departments of Medicine (Cardiology) (P.-Y.J.-C., J.-H.W., L.Z., S.K., I.N., J.A.S., L.B., R.Q., V.W., S.K.S., N.J.F.), Duke University Medical Center, Durham, NC
| | - Jonathan A Stiber
- From the Departments of Medicine (Cardiology) (P.-Y.J.-C., J.-H.W., L.Z., S.K., I.N., J.A.S., L.B., R.Q., V.W., S.K.S., N.J.F.), Duke University Medical Center, Durham, NC
| | - Leigh Brian
- From the Departments of Medicine (Cardiology) (P.-Y.J.-C., J.-H.W., L.Z., S.K., I.N., J.A.S., L.B., R.Q., V.W., S.K.S., N.J.F.), Duke University Medical Center, Durham, NC
| | - Rui Qi
- From the Departments of Medicine (Cardiology) (P.-Y.J.-C., J.-H.W., L.Z., S.K., I.N., J.A.S., L.B., R.Q., V.W., S.K.S., N.J.F.), Duke University Medical Center, Durham, NC
| | - Virginia Wertman
- From the Departments of Medicine (Cardiology) (P.-Y.J.-C., J.-H.W., L.Z., S.K., I.N., J.A.S., L.B., R.Q., V.W., S.K.S., N.J.F.), Duke University Medical Center, Durham, NC
| | - Sudha K Shenoy
- From the Departments of Medicine (Cardiology) (P.-Y.J.-C., J.-H.W., L.Z., S.K., I.N., J.A.S., L.B., R.Q., V.W., S.K.S., N.J.F.), Duke University Medical Center, Durham, NC.,Cell Biology (S.K.S., N.J.F.), Duke University Medical Center, Durham, NC
| | - Neil J Freedman
- From the Departments of Medicine (Cardiology) (P.-Y.J.-C., J.-H.W., L.Z., S.K., I.N., J.A.S., L.B., R.Q., V.W., S.K.S., N.J.F.), Duke University Medical Center, Durham, NC.,Cell Biology (S.K.S., N.J.F.), Duke University Medical Center, Durham, NC
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14
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Zhang MX, Cai Z, Zhang M, Wang XM, Wang Y, Zhao F, Zhou J, Luo MH, Zhu Q, Xu Z, Zeng WB, Zhong B, Lin D. USP20 Promotes Cellular Antiviral Responses via Deconjugating K48-Linked Ubiquitination of MITA. THE JOURNAL OF IMMUNOLOGY 2019; 202:2397-2406. [PMID: 30814308 DOI: 10.4049/jimmunol.1801447] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 02/04/2019] [Indexed: 12/31/2022]
Abstract
Mediator of IRF3 activation ([MITA] also known as STING) is a direct sensor of cyclic dinucleotide and critically mediates cytoplasmic DNA--triggered innate immune signaling. The activity of MITA is extensively regulated by ubiquitination and deubiquitination. In this study, we report that USP20 interacts with and removes K48-linked ubiquitin chains from MITA after HSV-1 infection, thereby stabilizing MITA and promoting cellular antiviral responses. Deletion of USP20 accelerates HSV-1-induced degradation of MITA and impairs phosphorylation of IRF3 and IκBα as well as subsequent induction of type I IFNs and proinflammatory cytokines after HSV-1 infection or cytoplasmic DNA challenge. Consistently, Usp20 -/- mice produce decreased type I IFNs and proinflammatory cytokines, exhibit increased susceptibility to lethal HSV-1 infection, and aggravated HSV-1 replication compared with Usp20 +/+ mice. In addition, complement of MITA into Usp20 -/- cells fully restores HSV-1-triggered signaling and inhibits HSV-1 infection. These findings suggest a crucial role of USP20 in maintaining the stability of MITA and promoting innate antiviral signaling.
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Affiliation(s)
- Meng-Xin Zhang
- College of Life Sciences, Wuhan University, Wuhan 430072, China.,Medical Research Institute, School of Medicine, Wuhan University, Wuhan 430071, China
| | - Zeng Cai
- College of Life Sciences, Wuhan University, Wuhan 430072, China.,Medical Research Institute, School of Medicine, Wuhan University, Wuhan 430071, China
| | - Man Zhang
- College of Life Sciences, Wuhan University, Wuhan 430072, China.,Medical Research Institute, School of Medicine, Wuhan University, Wuhan 430071, China
| | - Xiao-Meng Wang
- College of Life Sciences, Wuhan University, Wuhan 430072, China.,Medical Research Institute, School of Medicine, Wuhan University, Wuhan 430071, China
| | - Yaqin Wang
- Reproductive Medical Center, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Fei Zhao
- State Key Laboratory of Virology, Chinese Academy of Sciences Center for Excellence in Brain Science and Intelligence Technology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China
| | - Jing Zhou
- State Key Laboratory of Virology, Chinese Academy of Sciences Center for Excellence in Brain Science and Intelligence Technology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China
| | - Min-Hua Luo
- State Key Laboratory of Virology, Chinese Academy of Sciences Center for Excellence in Brain Science and Intelligence Technology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China
| | - Qiyun Zhu
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730046, China
| | - Zhigao Xu
- Department of Pathology, Center for Pathology and Molecular Diagnostics, Zhongnan Hospital of Wuhan University, Wuhan 430071, China; and
| | - Wen-Bo Zeng
- State Key Laboratory of Virology, Chinese Academy of Sciences Center for Excellence in Brain Science and Intelligence Technology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China;
| | - Bo Zhong
- College of Life Sciences, Wuhan University, Wuhan 430072, China; .,Medical Research Institute, School of Medicine, Wuhan University, Wuhan 430071, China
| | - Dandan Lin
- Cancer Center, Renmin Hospital of Wuhan University, Wuhan 430060, China
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15
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Abstract
Ubiquitination of G protein-coupled receptors (GPCRs) is an important dynamic posttranslational modification that has been linked to the intracellular trafficking of internalized GPCRs to lysosomes. Ubiquitination of GPCRs is mediated by specific E3 ubiquitin ligases that are scaffolded by the adaptor proteins called β-arrestins. Traditionally, detection of GPCR ubiquitination is achieved by using ubiquitin antibodies to Western blot immunoprecipitates of detergent-solubilized GPCRs expressed in heterologous cells. However, studies have also shown that bioluminescence resonance energy transfer (BRET)-based techniques can reveal ubiquitination of GPCRs in intact cells and in real time. This chapter describes a step-by-step protocol to evaluate ubiquitination of GPCRs using the BRET methodology.
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16
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Yu SMW, Jean-Charles PY, Abraham DM, Kaur S, Gareri C, Mao L, Rockman HA, Shenoy SK. The deubiquitinase ubiquitin-specific protease 20 is a positive modulator of myocardial β 1-adrenergic receptor expression and signaling. J Biol Chem 2018; 294:2500-2518. [PMID: 30538132 DOI: 10.1074/jbc.ra118.004926] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 11/23/2018] [Indexed: 12/27/2022] Open
Abstract
Reversible ubiquitination of G protein-coupled receptors regulates their trafficking and signaling; whether deubiquitinases regulate myocardial β1-adrenergic receptors (β1ARs) is unknown. We report that ubiquitin-specific protease 20 (USP20) deubiquitinates and attenuates lysosomal trafficking of the β1AR. β1AR-induced phosphorylation of USP20 Ser-333 by protein kinase A-α (PKAα) was required for optimal USP20-mediated regulation of β1AR lysosomal trafficking. Both phosphomimetic (S333D) and phosphorylation-impaired (S333A) USP20 possess intrinsic deubiquitinase activity equivalent to WT activity. However, unlike USP20 WT and S333D, the S333A mutant associated poorly with the β1AR and failed to deubiquitinate the β1AR. USP20-KO mice showed normal baseline systolic function but impaired β1AR-induced contractility and relaxation. Dobutamine stimulation did not increase cAMP in USP20-KO left ventricles (LVs), whereas NKH477-induced adenylyl cyclase activity was equivalent to WT. The USP20 homolog USP33, which shares redundant roles with USP20, had no effect on β1AR ubiquitination, but USP33 was up-regulated in USP20-KO hearts suggesting compensatory regulation. Myocardial β1AR expression in USP20-KO was drastically reduced, whereas β2AR expression was maintained as determined by radioligand binding in LV sarcolemmal membranes. Phospho-USP20 was significantly increased in LVs of wildtype (WT) mice after a 1-week catecholamine infusion and a 2-week chronic pressure overload induced by transverse aortic constriction (TAC). Phospho-USP20 was undetectable in β1AR KO mice subjected to TAC, suggesting a role for USP20 phosphorylation in cardiac response to pressure overload. We conclude that USP20 regulates β1AR signaling in vitro and in vivo Additionally, β1AR-induced USP20 phosphorylation may serve as a feed-forward mechanism to stabilize β1AR expression and signaling during pathological insults to the myocardium.
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Affiliation(s)
- Samuel Mon-Wei Yu
- From the Department of Medicine, Division of Cardiology, Duke University Medical Center, Durham, North Carolina 27710
| | - Pierre-Yves Jean-Charles
- From the Department of Medicine, Division of Cardiology, Duke University Medical Center, Durham, North Carolina 27710
| | - Dennis M Abraham
- From the Department of Medicine, Division of Cardiology, Duke University Medical Center, Durham, North Carolina 27710
| | - Suneet Kaur
- From the Department of Medicine, Division of Cardiology, Duke University Medical Center, Durham, North Carolina 27710
| | - Clarice Gareri
- From the Department of Medicine, Division of Cardiology, Duke University Medical Center, Durham, North Carolina 27710
| | - Lan Mao
- From the Department of Medicine, Division of Cardiology, Duke University Medical Center, Durham, North Carolina 27710
| | - Howard A Rockman
- From the Department of Medicine, Division of Cardiology, Duke University Medical Center, Durham, North Carolina 27710
| | - Sudha K Shenoy
- From the Department of Medicine, Division of Cardiology, Duke University Medical Center, Durham, North Carolina 27710
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17
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Dores MR, Trejo J. Endo-lysosomal sorting of G-protein-coupled receptors by ubiquitin: Diverse pathways for G-protein-coupled receptor destruction and beyond. Traffic 2018; 20:101-109. [PMID: 30353650 DOI: 10.1111/tra.12619] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2018] [Revised: 10/14/2018] [Accepted: 10/15/2018] [Indexed: 02/06/2023]
Abstract
Ubiquitin is covalently attached to substrate proteins in the form of a single ubiquitin moiety or polyubiquitin chains and has been generally linked to protein degradation, however, distinct types of ubiquitin linkages are also used to control other critical cellular processes like cell signaling. Over forty mammalian G protein-coupled receptors (GPCRs) have been reported to be ubiquitinated, but despite the diverse and rich complexity of GPCR signaling, ubiquitin has been largely ascribed to receptor degradation. Indeed, GPCR ubiquitination targets the receptors for degradation by lysosome, which is mediated by the Endosomal Sorting Complexes Required for Transport (ESCRT) machinery, and the proteasome. This has led to the view that ubiquitin and ESCRTs primarily function as the signal to target GPCRs for destruction. Contrary to this conventional view, studies indicate that ubiquitination of certain GPCRs and canonical ubiquitin-binding ESCRTs are not required for receptor degradation and revealed that diverse and complex pathways exist to regulate endo-lysosomal sorting of GPCRs. In other studies, GPCR ubiquitination has been shown to drive signaling and not receptor degradation and further revealed novel insight into the mechanisms by which GPCRs trigger the activity of the ubiquitination machinery. Here, we discuss the diverse pathways by which ubiquitin controls GPCR endo-lysosomal sorting and beyond.
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Affiliation(s)
- Michael R Dores
- Department of Biology, Hofstra University, Hempstead, New York
| | - JoAnn Trejo
- Department of Pharmacology, School of Medicine, University of California, San Diego, La Jolla, California
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18
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Deubiquitinating Enzymes Related to Autophagy: New Therapeutic Opportunities? Cells 2018; 7:cells7080112. [PMID: 30126257 PMCID: PMC6116007 DOI: 10.3390/cells7080112] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 08/13/2018] [Accepted: 08/17/2018] [Indexed: 12/21/2022] Open
Abstract
Autophagy is an evolutionary conserved catabolic process that allows for the degradation of intracellular components by lysosomes. This process can be triggered by nutrient deprivation, microbial infections or other challenges to promote cell survival under these stressed conditions. However, basal levels of autophagy are also crucial for the maintenance of proper cellular homeostasis by ensuring the selective removal of protein aggregates and dysfunctional organelles. A tight regulation of this process is essential for cellular survival and organismal health. Indeed, deregulation of autophagy is associated with a broad range of pathologies such as neuronal degeneration, inflammatory diseases, and cancer progression. Ubiquitination and deubiquitination of autophagy substrates, as well as components of the autophagic machinery, are critical regulatory mechanisms of autophagy. Here, we review the main evidence implicating deubiquitinating enzymes (DUBs) in the regulation of autophagy. We also discuss how they may constitute new therapeutic opportunities in the treatment of pathologies such as cancers, neurodegenerative diseases or infections.
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19
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Gupta MK, Mohan ML, Naga Prasad SV. G Protein-Coupled Receptor Resensitization Paradigms. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2018; 339:63-91. [PMID: 29776605 DOI: 10.1016/bs.ircmb.2018.03.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cellular responses to extracellular milieu/environment are driven by cell surface receptors that transmit the signal into the cells resulting in a synchronized and measured response. The ability to provide such exquisite responses to changes in external environment is mediated by the tight and yet, deliberate regulation of cell surface receptor function. In this regard, the seven transmembrane G protein-coupled receptors (GPCRs) are the largest family of cell surface receptors that regulate responses like cardiac contractility, vision, and olfaction including platelet activation. GPCRs regulate these plethora of events through GPCR-activation, -desensitization, and -resensitization. External stimuli (ligands or agonists) activate GPCR initiating downstream signals. The activated GPCR undergoes inactivation or desensitization by phosphorylation and binding of β-arrestin resulting in diminution of downstream signals. The desensitized GPCRs are internalized into endosomes, wherein they undergo dephosphorylation or resensitization by protein phosphatase to be recycled back to the cell membrane as naïve GPCR ready for the next wave of stimuli. Despite the knowledge that activation, desensitization, and resensitization shoulder an equal role in maintaining GPCR function, major advances have been made in understanding activation and desensitization compared to resensitization. However, increasing evidence shows that resensitization is exquisitely regulated process, thereby contributing to the dynamic regulation of GPCR function. In recognition of these observations, in this chapter we discuss the key advances on the mechanistic underpinning that drive and regulate GPCR function with a focus on resensitization.
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Affiliation(s)
- Manveen K Gupta
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Maradumane L Mohan
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Sathyamangla V Naga Prasad
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States.
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20
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Steyfkens F, Zhang Z, Van Zeebroeck G, Thevelein JM. Multiple Transceptors for Macro- and Micro-Nutrients Control Diverse Cellular Properties Through the PKA Pathway in Yeast: A Paradigm for the Rapidly Expanding World of Eukaryotic Nutrient Transceptors Up to Those in Human Cells. Front Pharmacol 2018; 9:191. [PMID: 29662449 PMCID: PMC5890159 DOI: 10.3389/fphar.2018.00191] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Accepted: 02/20/2018] [Indexed: 12/17/2022] Open
Abstract
The nutrient composition of the medium has dramatic effects on many cellular properties in the yeast Saccharomyces cerevisiae. In addition to the well-known specific responses to starvation for an essential nutrient, like nitrogen or phosphate, the presence of fermentable sugar or a respirative carbon source leads to predominance of fermentation or respiration, respectively. Fermenting and respiring cells also show strong differences in other properties, like storage carbohydrate levels, general stress tolerance and cellular growth rate. However, the main glucose repression pathway, which controls the switch between respiration and fermentation, is not involved in control of these properties. They are controlled by the protein kinase A (PKA) pathway. Addition of glucose to respiring yeast cells triggers cAMP synthesis, activation of PKA and rapid modification of its targets, like storage carbohydrate levels, general stress tolerance and growth rate. However, starvation of fermenting cells in a glucose medium for any essential macro- or micro-nutrient counteracts this effect, leading to downregulation of PKA and its targets concomitant with growth arrest and entrance into G0. Re-addition of the lacking nutrient triggers rapid activation of the PKA pathway, without involvement of cAMP as second messenger. Investigation of the sensing mechanism has revealed that the specific high-affinity nutrient transporter(s) induced during starvation function as transporter-receptors or transceptors for rapid activation of PKA upon re-addition of the missing substrate. In this way, transceptors have been identified for amino acids, ammonium, phosphate, sulfate, iron, and zinc. We propose a hypothesis for regulation of PKA activity by nutrient transceptors to serve as a conceptual framework for future experimentation. Many properties of transceptors appear to be similar to those of classical receptors and nutrient transceptors may constitute intermediate forms in the development of receptors from nutrient transporters during evolution. The nutrient-sensing transceptor system in yeast for activation of the PKA pathway has served as a paradigm for similar studies on candidate nutrient transceptors in other eukaryotes and we succinctly discuss the many examples of transceptors that have already been documented in other yeast species, filamentous fungi, plants, and animals, including the examples in human cells.
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Affiliation(s)
- Fenella Steyfkens
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Leuven, Belgium.,Center for Microbiology, VIB, Flanders, Belgium
| | - Zhiqiang Zhang
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Leuven, Belgium.,Center for Microbiology, VIB, Flanders, Belgium
| | - Griet Van Zeebroeck
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Leuven, Belgium.,Center for Microbiology, VIB, Flanders, Belgium
| | - Johan M Thevelein
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Leuven, Belgium.,Center for Microbiology, VIB, Flanders, Belgium
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21
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Kim JH, Seo D, Kim SJ, Choi DW, Park JS, Ha J, Choi J, Lee JH, Jung SM, Seo KW, Lee EW, Lee YS, Cheong H, Choi CY, Park SH. The deubiquitinating enzyme USP20 stabilizes ULK1 and promotes autophagy initiation. EMBO Rep 2018; 19:embr.201744378. [PMID: 29487085 DOI: 10.15252/embr.201744378] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 01/29/2018] [Accepted: 02/05/2018] [Indexed: 12/12/2022] Open
Abstract
Autophagy begins with the formation of autophagosomes, a process that depends on the activity of the serine/threonine kinase ULK1 (hATG1). Although earlier studies indicated that ULK1 activity is regulated by dynamic polyubiquitination, the deubiquitinase involved in the regulation of ULK1 remained unknown. In this study, we demonstrate that ubiquitin-specific protease 20 (USP20) acts as a positive regulator of autophagy initiation through stabilizing ULK1. At basal state, USP20 binds to and stabilizes ULK1 by removing the ubiquitin moiety, thereby interfering with the lysosomal degradation of ULK1. The stabilization of basal ULK1 protein levels is required for the initiation of starvation-induced autophagy, since the depletion of USP20 by RNA interference inhibits LC3 puncta formation, a marker of autophagic flux. At later stages of autophagy, USP20 dissociates from ULK1, resulting in enhanced ULK1 degradation and apoptosis. Taken together, our findings provide the first evidence that USP20 plays a crucial role in autophagy initiation by maintaining the basal expression level of ULK1.
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Affiliation(s)
- Jun Hwan Kim
- Department of Biological Sciences, Sungkyunkwan University, Suwon, Korea
| | - Dongyeob Seo
- Department of Biological Sciences, Sungkyunkwan University, Suwon, Korea
| | - Sun-Jick Kim
- Department of Biological Sciences, Sungkyunkwan University, Suwon, Korea
| | - Dong Wook Choi
- Department of Biological Sciences, Sungkyunkwan University, Suwon, Korea
| | - Jin Seok Park
- Department of Biological Sciences, Sungkyunkwan University, Suwon, Korea
| | - Jihoon Ha
- Department of Biological Sciences, Sungkyunkwan University, Suwon, Korea
| | - Jungwon Choi
- Division of Cancer Biology, Research Institute, National Cancer Center, Goyang, Korea
| | - Ji-Hyung Lee
- Department of Biological Sciences, Sungkyunkwan University, Suwon, Korea
| | - Su Myung Jung
- Department of Biological Sciences, Sungkyunkwan University, Suwon, Korea
| | - Kyoung-Wan Seo
- Department of Biological Sciences, Sungkyunkwan University, Suwon, Korea
| | - Eun-Woo Lee
- Division of Biomedical Science, Korea Research Institute of Bioscience & Biotechnology, Daejeon, Korea
| | - Youn Sook Lee
- Department of Biological Sciences, Sungkyunkwan University, Suwon, Korea
| | - Heesun Cheong
- Division of Cancer Biology, Research Institute, National Cancer Center, Goyang, Korea
| | - Cheol Yong Choi
- Department of Biological Sciences, Sungkyunkwan University, Suwon, Korea
| | - Seok Hee Park
- Department of Biological Sciences, Sungkyunkwan University, Suwon, Korea
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22
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Jean-Charles PY, Yu SMW, Abraham D, Kommaddi RP, Mao L, Strachan RT, Zhang ZS, Bowles DE, Brian L, Stiber JA, Jones SN, Koch WJ, Rockman HA, Shenoy SK. Mdm2 regulates cardiac contractility by inhibiting GRK2-mediated desensitization of β-adrenergic receptor signaling. JCI Insight 2017; 2:95998. [PMID: 28878120 DOI: 10.1172/jci.insight.95998] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 07/27/2017] [Indexed: 12/22/2022] Open
Abstract
The oncoprotein Mdm2 is a RING domain-containing E3 ubiquitin ligase that ubiquitinates G protein-coupled receptor kinase 2 (GRK2) and β-arrestin2, thereby regulating β-adrenergic receptor (βAR) signaling and endocytosis. Previous studies showed that cardiac Mdm2 expression is critical for controlling p53-dependent apoptosis during early embryonic development, but the role of Mdm2 in the developed adult heart is unknown. We aimed to identify if Mdm2 affects βAR signaling and cardiac function in adult mice. Using Mdm2/p53-KO mice, which survive for 9-12 months, we identified a critical and potentially novel role for Mdm2 in the adult mouse heart through its regulation of cardiac β1AR signaling. While baseline cardiac function was mostly similar in both Mdm2/p53-KO and wild-type (WT) mice, isoproterenol-induced cardiac contractility in Mdm2/p53-KO was significantly blunted compared with WT mice. Isoproterenol increased cAMP in left ventricles of WT but not of Mdm2/p53-KO mice. Additionally, while basal and forskolin-induced calcium handling in isolated Mdm2/p53-KO and WT cardiomyocytes were equivalent, isoproterenol-induced calcium handling in Mdm2/p53-KO was impaired. Mdm2/p53-KO hearts expressed 2-fold more GRK2 than WT. GRK2 polyubiquitination via lysine-48 linkages was significantly reduced in Mdm2/p53-KO hearts. Tamoxifen-inducible cardiomyocyte-specific deletion of Mdm2 in adult mice also led to a significant increase in GRK2, and resulted in severely impaired cardiac function, high mortality, and no detectable βAR responsiveness. Gene delivery of either Mdm2 or GRK2-CT in vivo using adeno-associated virus 9 (AAV9) effectively rescued β1AR-induced cardiac contractility in Mdm2/p53-KO. These findings reveal a critical p53-independent physiological role of Mdm2 in adult hearts, namely, regulation of GRK2-mediated desensitization of βAR signaling.
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Affiliation(s)
| | | | | | | | - Lan Mao
- Department of Medicine, Division of Cardiology, and
| | | | | | - Dawn E Bowles
- Department of Surgery, Duke University Medical Center, Durham, North Carolina, USA
| | - Leigh Brian
- Department of Medicine, Division of Cardiology, and
| | | | - Stephen N Jones
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Walter J Koch
- Center for Translational Medicine, Department of Pharmacology, Temple University School of Medicine, Philadelphia, Pennsylvania, USA
| | - Howard A Rockman
- Department of Medicine, Division of Cardiology, and.,Department of Cell Biology, and.,Department of Molecular Genetics, Duke University Medical Center, Durham, North Carolina, USA
| | - Sudha K Shenoy
- Department of Medicine, Division of Cardiology, and.,Department of Cell Biology, and
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23
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Deubiquitylating enzymes in receptor endocytosis and trafficking. Biochem J 2017; 473:4507-4525. [PMID: 27941029 DOI: 10.1042/bcj20160826] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 09/15/2016] [Accepted: 09/16/2016] [Indexed: 12/25/2022]
Abstract
In recent times, our knowledge of the roles ubiquitin plays in multiple cellular processes has expanded exponentially, with one example being the role of ubiquitin in receptor endocytosis and trafficking. This has prompted a multitude of studies examining how the different machinery involved in the addition and removal of ubiquitin can influence this process. Multiple deubiquitylating enzymes (DUBs) have been implicated either in facilitating receptor endocytosis and lysosomal degradation or in rescuing receptor levels by preventing endocytosis and/or promoting recycling to the plasma membrane. In this review, we will discuss in detail what is currently known about the role of DUBs in regulating the endocytosis of various transmembrane receptors and ion channels. We will also expand upon the role DUBs play in receptor sorting at the multivesicular body to determine whether a receptor is recycled or trafficked to the lysosome for degradation. Finally, we will briefly discuss how the DUBs implicated in these processes may contribute to the pathogenesis of a range of diseases, and thus the potential these have as therapeutic targets.
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24
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Regulation of G Protein-Coupled Receptors by Ubiquitination. Int J Mol Sci 2017; 18:ijms18050923. [PMID: 28448471 PMCID: PMC5454836 DOI: 10.3390/ijms18050923] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 04/20/2017] [Accepted: 04/23/2017] [Indexed: 02/07/2023] Open
Abstract
G protein-coupled receptors (GPCRs) comprise the largest family of membrane receptors that control many cellular processes and consequently often serve as drug targets. These receptors undergo a strict regulation by mechanisms such as internalization and desensitization, which are strongly influenced by posttranslational modifications. Ubiquitination is a posttranslational modification with a broad range of functions that is currently gaining increased appreciation as a regulator of GPCR activity. The role of ubiquitination in directing GPCRs for lysosomal degradation has already been well-established. Furthermore, this modification can also play a role in targeting membrane and endoplasmic reticulum-associated receptors to the proteasome. Most recently, ubiquitination was also shown to be involved in GPCR signaling. In this review, we present current knowledge on the molecular basis of GPCR regulation by ubiquitination, and highlight the importance of E3 ubiquitin ligases, deubiquitinating enzymes and β-arrestins. Finally, we discuss classical and newly-discovered functions of ubiquitination in controlling GPCR activity.
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25
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Wang C, Yang C, Ji J, Jiang J, Shi M, Cai Q, Yu Y, Zhu Z, Zhang J. Deubiquitinating enzyme USP20 is a positive regulator of Claspin and suppresses the malignant characteristics of gastric cancer cells. Int J Oncol 2017; 50:1136-1146. [PMID: 28350092 PMCID: PMC5363881 DOI: 10.3892/ijo.2017.3904] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2016] [Accepted: 01/23/2017] [Indexed: 11/29/2022] Open
Abstract
The aim of the present study was to investigate the clinical significance, the biological function and the mechanisms of USP20 in gastric cancer. The expression of USP20 in 89 pairs of primary gastric cancer and peritumoral gastric tissues specimens were measured by immunohistochemistry. The correlation of USP20 expression with the survival and the clinicopathological characteristics of patients were analyzed. Moreover, the underlying mechanisms of ectopic USP20 expression and its impact on GC cells were also investigated. We found that the expression of USP20 is relatively low in GC tissues and negatively correlated with tumor size, tumor invasion and TNM staging. High expression of USP20 in GC predicted longer survival. Experimentally, small interfering RNA-mediated knockdown of USP20 expression significantly promoted cell proliferation, accelerated G1-S phase transition and attenuated the autophagy activity. Overexpression of USP20 led to the inhibition of proliferation, G1-S cell cycle transition delay and autophagy activation. Mechanistically, we confirmed that silencing the expression of USP20 in GC cells could reduce Claspin protein levels without altering Claspin mRNA levels, which is involved in the antitumor activity of USP20. Furthermore, the expression level of Claspin was relatively higher in peritumoral tissue than that of GC tissues and higher expression of Claspin in GC was also correlated with good prognosis of patients. Given its pivotal role in gastric tumorigenesis and progression, USP20 functioned as the tumor suppressor in GC and possessed promising value to be a therapeutic target for GC.
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Affiliation(s)
- Chao Wang
- Department of Oncology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, P.R. China
| | - Chen Yang
- Department of Oncology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, P.R. China
| | - Jun Ji
- Department of Surgery, Shanghai Key Laboratory of Gastric Neoplasms, Shanghai Institute of Digestive Surgery, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, P.R. China
| | - Jinling Jiang
- Department of Oncology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, P.R. China
| | - Min Shi
- Department of Oncology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, P.R. China
| | - Qu Cai
- Department of Surgery, Shanghai Key Laboratory of Gastric Neoplasms, Shanghai Institute of Digestive Surgery, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, P.R. China
| | - Yingyan Yu
- Department of Surgery, Shanghai Key Laboratory of Gastric Neoplasms, Shanghai Institute of Digestive Surgery, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, P.R. China
| | - Zhenggang Zhu
- Department of Oncology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, P.R. China
| | - Jun Zhang
- Department of Oncology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, P.R. China
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26
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Rajagopal S, Shenoy SK. GPCR desensitization: Acute and prolonged phases. Cell Signal 2017; 41:9-16. [PMID: 28137506 DOI: 10.1016/j.cellsig.2017.01.024] [Citation(s) in RCA: 195] [Impact Index Per Article: 27.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Accepted: 01/25/2017] [Indexed: 01/04/2023]
Abstract
G protein-coupled receptors (GPCRs) transduce a wide array of extracellular signals and regulate virtually every aspect of physiology. While GPCR signaling is essential, overstimulation can be deleterious, resulting in cellular toxicity or uncontrolled cellular growth. Accordingly, nature has developed a number of mechanisms for limiting GPCR signaling, which are broadly referred to as desensitization, and refer to a decrease in response to repeated or continuous stimulation. Short-term desensitization occurs over minutes, and is primarily associated with β-arrestins preventing G protein interaction with a GPCR. Longer-term desensitization, referred to as downregulation, occurs over hours to days, and involves receptor internalization into vesicles, degradation in lysosomes and decreased receptor mRNA levels through unclear mechanisms. Phosphorylation of the receptor by GPCR kinases (GRKs) and the recruitment of β-arrestins is critical to both these short- and long-term desensitization mechanisms. In addition to phosphorylation, both the GPCR and β-arrestins are modified post-translationally in several ways, including by ubiquitination. For many GPCRs, receptor ubiquitination promotes degradation of agonist-activated receptors in the lysosomes. Other proteins also play important roles in desensitization, including phosphodiesterases, RGS family proteins and A-kinase-anchoring proteins. Together, this intricate network of kinases, ubiquitin ligases, and adaptor proteins orchestrate the acute and prolonged desensitization of GPCRs.
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Affiliation(s)
| | - Sudha K Shenoy
- Department of Medicine (Cardiology), Durham, NC, USA; Department of Cell Biology, Duke University Medical Center, Durham, NC, USA.
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27
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Jean-Charles PY, Freedman NJ, Shenoy SK. Chapter Nine - Cellular Roles of Beta-Arrestins as Substrates and Adaptors of Ubiquitination and Deubiquitination. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2016; 141:339-69. [PMID: 27378762 DOI: 10.1016/bs.pmbts.2016.04.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
β-Arrestin1 and β-arrestin2 are homologous adaptor proteins that are ubiquitously expressed in mammalian cells. They belong to a four-member family of arrestins that regulate the vast family of seven-transmembrane receptors that couple to heterotrimeric G proteins (7TMRs or GPCRs), and that modulate 7TMR signal transduction. β-Arrestins were originally identified in the context of signal inhibition via the 7TMRs because they competed with and thereby blocked G protein coupling to 7TMRs. Currently, in addition to their role as desensitizers of signaling, β-arrestins are appreciated as multifunctional adaptors that mediate trafficking and signal transduction of not only 7TMRs, but a growing list of additional receptors, ion channels, and nonreceptor proteins. β-Arrestins' interactions with their multifarious partners are based on their dynamic conformational states rather than particular domain-domain interactions. β-Arrestins adopt activated conformations upon 7TMR association. In addition, β-arrestins undergo various posttranslational modifications that are choreographed by activated 7TMRs, including phosphorylation, ubiquitination, acetylation, nitrosylation, and SUMOylation. Ubiquitination of β-arrestins is critical for their high-affinity interaction with 7TMRs as well as with endocytic adaptor proteins and signaling kinases. β-Arrestins also function as critical adaptors for ubiquitination and deubiquitination of various cellular proteins, and thereby affect the longevity of signal transducers and the intensity of signal transmission.
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Affiliation(s)
- P-Y Jean-Charles
- Department of Medicine (Cardiology), Duke University Medical Center, Durham, North Carolina, United States
| | - N J Freedman
- Department of Medicine (Cardiology), Duke University Medical Center, Durham, North Carolina, United States; Department of Cell Biology, Duke University Medical Center, Durham, North Carolina, United States
| | - S K Shenoy
- Department of Medicine (Cardiology), Duke University Medical Center, Durham, North Carolina, United States; Department of Cell Biology, Duke University Medical Center, Durham, North Carolina, United States.
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28
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Jean-Charles PY, Rajiv V, Shenoy SK. Ubiquitin-Related Roles of β-Arrestins in Endocytic Trafficking and Signal Transduction. J Cell Physiol 2016; 231:2071-80. [PMID: 26790995 DOI: 10.1002/jcp.25317] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 01/20/2016] [Indexed: 12/25/2022]
Abstract
The non-visual arrestins, β-arrestin1, and β-arrestin2 were originally identified as proteins that bind to seven-transmembrane receptors (7TMRs, also called G protein-coupled receptors, GPCRs) and block heterotrimeric G protein activation, thus leading to desensitization of transmembrane signaling. However, as subsequent discoveries have continually demonstrated, their functionality is not constrained to desensitization. They are now recognized for their critical roles in mediating intracellular trafficking of 7TMRs, growth factor receptors, ion transporters, ion channels, nuclear receptors, and non-receptor proteins. Additionally, they function as crucial mediators of ubiquitination of 7TMRs as well as other receptors and non-receptor proteins. Recently, emerging studies suggest that a class of proteins with predicted structural features of β-arrestins regulate substrate ubiquitination in yeast and higher mammals, lending support to the idea that the adaptor role of β-arrestins in protein ubiquitination is evolutionarily conserved. β-arrestins also function as scaffolds for kinases and transduce signals from 7TMRs through pathways that do not require G protein activation. Remarkably, the endocytic and scaffolding functions of β-arrestin are intertwined with its ubiquitination status; the dynamic and site specific ubiquitination on β-arrestin plays a critical role in stabilizing β-arrestin-7TMR association and the formation of signalosomes. This review summarizes the current findings on ubiquitin-dependent regulation of 7TMRs as well as β-arrestins and the potential role of reversible ubiquitination as a "biological switch" in signal transduction. J. Cell. Physiol. 231: 2071-2080, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
| | - Vishwaesh Rajiv
- Department of Medicine (Cardiology), Duke University Medical Center, Durham, North Carolina
| | - Sudha K Shenoy
- Department of Medicine (Cardiology), Duke University Medical Center, Durham, North Carolina.,Department of Cell Biology, Duke University Medical Center, Durham, North Carolina
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29
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Jean-Charles PY, Zhang L, Wu JH, Han SO, Brian L, Freedman NJ, Shenoy SK. Ubiquitin-specific Protease 20 Regulates the Reciprocal Functions of β-Arrestin2 in Toll-like Receptor 4-promoted Nuclear Factor κB (NFκB) Activation. J Biol Chem 2016; 291:7450-64. [PMID: 26839314 DOI: 10.1074/jbc.m115.687129] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Indexed: 12/19/2022] Open
Abstract
Toll-like receptor 4 (TLR4) promotes vascular inflammatory disorders such as neointimal hyperplasia and atherosclerosis. TLR4 triggers NFκB signaling through the ubiquitin ligase TRAF6 (tumor necrosis factor receptor-associated factor 6). TRAF6 activity can be impeded by deubiquitinating enzymes like ubiquitin-specific protease 20 (USP20), which can reverse TRAF6 autoubiquitination, and by association with the multifunctional adaptor protein β-arrestin2. Although β-arrestin2 effects on TRAF6 suggest an anti-inflammatory role, physiologic β-arrestin2 promotes inflammation in atherosclerosis and neointimal hyperplasia. We hypothesized that anti- and proinflammatory dimensions of β-arrestin2 activity could be dictated by β-arrestin2's ubiquitination status, which has been linked with its ability to scaffold and localize activated ERK1/2 to signalosomes. With purified proteins and in intact cells, our protein interaction studies showed that TRAF6/USP20 association and subsequent USP20-mediated TRAF6 deubiquitination were β-arrestin2-dependent. Generation of transgenic mice with smooth muscle cell-specific expression of either USP20 or its catalytically inactive mutant revealed anti-inflammatory effects of USP20in vivoandin vitro Carotid endothelial denudation showed that antagonizing smooth muscle cell USP20 activity increased NFκB activation and neointimal hyperplasia. We found that β-arrestin2 ubiquitination was promoted by TLR4 and reversed by USP20. The association of USP20 with β-arrestin2 was augmented when β-arrestin2 ubiquitination was prevented and reduced when β-arrestin2 ubiquitination was rendered constitutive. Constitutive β-arrestin2 ubiquitination also augmented NFκB activation. We infer that pro- and anti-inflammatory activities of β-arrestin2 are determined by β-arrestin2 ubiquitination and that changes in USP20 expression and/or activity can therefore regulate inflammatory responses, at least in part, by defining the ubiquitination status of β-arrestin2.
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Affiliation(s)
| | | | - Jiao-Hui Wu
- From the Departments of Medicine (Cardiology) and
| | - Sang-Oh Han
- From the Departments of Medicine (Cardiology) and
| | - Leigh Brian
- From the Departments of Medicine (Cardiology) and
| | - Neil J Freedman
- From the Departments of Medicine (Cardiology) and Cell Biology, Duke University Medical Center, Durham, North Carolina 27710
| | - Sudha K Shenoy
- From the Departments of Medicine (Cardiology) and Cell Biology, Duke University Medical Center, Durham, North Carolina 27710
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30
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Jean-Charles PY, Snyder JC, Shenoy SK. Chapter One - Ubiquitination and Deubiquitination of G Protein-Coupled Receptors. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2016; 141:1-55. [PMID: 27378754 DOI: 10.1016/bs.pmbts.2016.05.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The seven-transmembrane containing G protein-coupled receptors (GPCRs) constitute the largest family of cell-surface receptors. Transmembrane signaling by GPCRs is fundamental to many aspects of physiology including vision, olfaction, cardiovascular, and reproductive functions as well as pain, behavior and psychomotor responses. The duration and magnitude of signal transduction is tightly controlled by a series of coordinated trafficking events that regulate the cell-surface expression of GPCRs at the plasma membrane. Moreover, the intracellular trafficking profiles of GPCRs can correlate with the signaling efficacy and efficiency triggered by the extracellular stimuli that activate GPCRs. Of the various molecular mechanisms that impart selectivity, sensitivity and strength of transmembrane signaling, ubiquitination of the receptor protein plays an important role because it defines both trafficking and signaling properties of the activated GPCR. Ubiquitination of proteins was originally discovered in the context of lysosome-independent degradation of cytosolic proteins by the 26S proteasome; however a large body of work suggests that ubiquitination also orchestrates the downregulation of membrane proteins in the lysosomes. In the case of GPCRs, such ubiquitin-mediated lysosomal degradation engenders long-term desensitization of transmembrane signaling. To date about 40 GPCRs are known to be ubiquitinated. For many GPCRs, ubiquitination plays a major role in postendocytic trafficking and sorting to the lysosomes. This chapter will focus on the patterns and functional roles of GPCR ubiquitination, and will describe various molecular mechanisms involved in GPCR ubiquitination.
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Affiliation(s)
- P-Y Jean-Charles
- Department of Medicine (Cardiology), Duke University Medical Center, Durham, NC, United States
| | - J C Snyder
- Department of Cell Biology, Duke University Medical Center, Durham, NC, United States
| | - S K Shenoy
- Department of Medicine (Cardiology), Duke University Medical Center, Durham, NC, United States; Department of Cell Biology, Duke University Medical Center, Durham, NC, United States.
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31
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Grimsey NJ, Coronel LJ, Cordova IC, Trejo J. Recycling and Endosomal Sorting of Protease-activated Receptor-1 Is Distinctly Regulated by Rab11A and Rab11B Proteins. J Biol Chem 2015; 291:2223-36. [PMID: 26635365 DOI: 10.1074/jbc.m115.702993] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Indexed: 11/06/2022] Open
Abstract
Protease-activated receptor-1 (PAR1) is a G protein-coupled receptor that undergoes proteolytic irreversible activation by coagulant and anti-coagulant proteases. Given the irreversible activation of PAR1, signaling by the receptor is tightly regulated through desensitization and intracellular trafficking. PAR1 displays both constitutive and agonist-induced internalization. Constitutive internalization of PAR1 is important for generating an internal pool of naïve receptors that replenish the cell surface and facilitate resensitization, whereas agonist-induced internalization of PAR1 is critical for terminating G protein signaling. We showed that PAR1 constitutive internalization is mediated by the adaptor protein complex-2 (AP-2), whereas AP-2 and epsin control agonist-induced PAR1 internalization. However, the mechanisms that regulate PAR1 recycling are not known. In the present study we screened a siRNA library of 140 different membrane trafficking proteins to identify key regulators of PAR1 intracellular trafficking. In addition to known mediators of PAR1 endocytosis, we identified Rab11B as a critical regulator of PAR1 trafficking. We found that siRNA-mediated depletion of Rab11B and not Rab11A blocks PAR1 recycling, which enhanced receptor lysosomal degradation. Although Rab11A is not required for PAR1 recycling, depletion of Rab11A resulted in intracellular accumulation of PAR1 through disruption of basal lysosomal degradation of the receptor. Moreover, enhanced degradation of PAR1 observed in Rab11B-deficient cells is blocked by depletion of Rab11A and the autophagy related-5 protein, suggesting that PAR1 is shuttled to an autophagic degradation pathway in the absence of Rab11B recycling. Together these findings suggest that Rab11A and Rab11B differentially regulate intracellular trafficking of PAR1 through distinct endosomal sorting mechanisms.
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Affiliation(s)
- Neil J Grimsey
- From the Department of Pharmacology, School of Medicine, University of California, San Diego, La Jolla, California 92093
| | - Luisa J Coronel
- From the Department of Pharmacology, School of Medicine, University of California, San Diego, La Jolla, California 92093
| | - Isabel Canto Cordova
- From the Department of Pharmacology, School of Medicine, University of California, San Diego, La Jolla, California 92093
| | - JoAnn Trejo
- From the Department of Pharmacology, School of Medicine, University of California, San Diego, La Jolla, California 92093
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32
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Magraoui FE, Reidick C, Meyer HE, Platta HW. Autophagy-Related Deubiquitinating Enzymes Involved in Health and Disease. Cells 2015; 4:596-621. [PMID: 26445063 PMCID: PMC4695848 DOI: 10.3390/cells4040596] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 09/15/2015] [Accepted: 09/30/2015] [Indexed: 02/06/2023] Open
Abstract
Autophagy is an evolutionarily-conserved process that delivers diverse cytoplasmic components to the lysosomal compartment for either recycling or degradation. This involves the removal of protein aggregates, the turnover of organelles, as well as the elimination of intracellular pathogens. In this situation, when only specific cargoes should be targeted to the lysosome, the potential targets can be selectively marked by the attachment of ubiquitin in order to be recognized by autophagy-receptors. Ubiquitination plays a central role in this process, because it regulates early signaling events during the induction of autophagy and is also used as a degradation-tag on the potential autophagic cargo protein. Here, we review how the ubiquitin-dependent steps of autophagy are balanced or counteracted by deubiquitination events. Moreover, we highlight the functional role of the corresponding deubiquitinating enzymes and discuss how they might be involved in the occurrence of cancer, neurodegenerative diseases or infection with pathogenic bacteria.
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Affiliation(s)
- Fouzi El Magraoui
- Biomedizinische Forschung, Human Brain Proteomics II, Leibniz-Institut für Analytische Wissenschaften - ISAS -e.V. 44139 Dortmund, Germany.
| | - Christina Reidick
- Biochemie Intrazellulärer Transportprozesse, Ruhr-Universität Bochum, 44801 Bochum, Germany.
| | - Hemut E Meyer
- Biomedizinische Forschung, Human Brain Proteomics II, Leibniz-Institut für Analytische Wissenschaften - ISAS -e.V. 44139 Dortmund, Germany.
| | - Harald W Platta
- Biochemie Intrazellulärer Transportprozesse, Ruhr-Universität Bochum, 44801 Bochum, Germany.
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33
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Rinaldi L, Sepe M, Donne RD, Feliciello A. A dynamic interface between ubiquitylation and cAMP signaling. Front Pharmacol 2015; 6:177. [PMID: 26388770 PMCID: PMC4559665 DOI: 10.3389/fphar.2015.00177] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 08/06/2015] [Indexed: 01/01/2023] Open
Abstract
Phosphorylation waves drive the propagation of signals generated in response to hormones and growth factors in target cells. cAMP is an ancient second messenger implicated in key biological functions. In mammals, most of the effects elicited by cAMP are mediated by protein kinase A (PKA). Activation of the kinase by cAMP results in the phosphorylation of a variety of cellular substrates, leading to differentiation, proliferation, survival, metabolism. The identification of scaffold proteins, namely A-Kinase Anchor proteins (AKAPs), that localize PKA in specific cellular districts, provided critical cues for our understanding of the role played by cAMP in cell biology. Multivalent complexes are assembled by AKAPs and include signaling enzymes, mRNAs, adapter molecules, receptors and ion channels. A novel development derived from the molecular analysis of these complexes nucleated by AKAPs is represented by the presence of components of the ubiquitin-proteasome system (UPS). More to it, the AKAP complex can be regulated by the UPS, eliciting relevant effects on downstream cAMP signals. This represents a novel, yet previously unpredicted interface between compartmentalized signaling and the UPS. We anticipate that impairment of these regulatory mechanisms could promote cell dysfunction and disease. Here, we will focus on the reciprocal regulation between cAMP signaling and UPS, and its relevance to human degenerative and proliferative disorders.
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Affiliation(s)
- Laura Rinaldi
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, University of Naples Federico II , Naples, Italy
| | - Maria Sepe
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, University of Naples Federico II , Naples, Italy
| | - Rossella Delle Donne
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, University of Naples Federico II , Naples, Italy
| | - Antonio Feliciello
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, University of Naples Federico II , Naples, Italy
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