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Harnessing the Power of Eph/ephrin Biosemiotics for Theranostic Applications. Pharmaceuticals (Basel) 2020; 13:ph13060112. [PMID: 32492868 PMCID: PMC7345574 DOI: 10.3390/ph13060112] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Revised: 05/26/2020] [Accepted: 05/27/2020] [Indexed: 02/07/2023] Open
Abstract
Comprehensive basic biological knowledge of the Eph/ephrin system in the physiologic setting is needed to facilitate an understanding of its role and the effects of pathological processes on its activity, thereby paving the way for development of prospective therapeutic targets. To this end, this review briefly addresses what is currently known and being investigated in order to highlight the gaps and possible avenues for further investigation to capitalize on their diverse potential.
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Salem AF, Gambini L, Udompholkul P, Baggio C, Pellecchia M. Therapeutic Targeting of Pancreatic Cancer via EphA2 Dimeric Agonistic Agents. Pharmaceuticals (Basel) 2020; 13:ph13050090. [PMID: 32397624 PMCID: PMC7281375 DOI: 10.3390/ph13050090] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 04/30/2020] [Accepted: 05/05/2020] [Indexed: 01/05/2023] Open
Abstract
Recently, we reported on potent EphA2 targeting compounds and demonstrated that dimeric versions of such agents can exhibit remarkably increased agonistic activity in cellular assays compared to the monomers. Here we further characterize the activity of dimeric compounds at the structural, biochemical, and cellular level. In particular, we propose a structural model for the mechanism of receptor activation by dimeric agents and characterize the effect of most potent compounds in inducing EphA2 activation and degradation in a pancreatic cancer cell line. These cellular studies indicate that the pro-migratory effects induced by the receptor can be reversed in EphA2 knockout cells, by treatment with either a dimeric natural ligand (ephrinA1-Fc), or by our synthetic agonistic dimers. Based on these data we conclude that the proposed agents hold great potential as possible therapeutics in combination with standard of care, where these could help suppressing a major driver for cell migration and tumor metastases. Finally, we also found that, similar to ephrinA1-Fc, dimeric agents cause a sustained internalization of the EphA2 receptor, hence, with proper derivatizations, these could also be used to deliver chemotherapy selectively to pancreatic tumors.
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Phan NN, Liu S, Wang CY, Hsu HP, Lai MD, Li CY, Chen CF, Chiao CC, Yen MC, Sun Z, Jiang JZ. Overexpressed gene signature of EPH receptor A/B family in cancer patients-comprehensive analyses from the public high-throughput database. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2020; 13:1220-1242. [PMID: 32509099 PMCID: PMC7270671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Accepted: 03/27/2020] [Indexed: 06/11/2023]
Abstract
Although a previous study suggested that erythropoietin-producing hepatoma (EPH) receptors play important roles in tumor progression and the overexpression of EPHs in cancer patients is related to poor prognoses, high-throughput gene expression profiling of EPH family members in different types and subtypes of cancers has so far not been conducted. We herein carried out a series of bioinformatic analyses on expressive profiles of every EPH member across 21 different types of clinical cancers versus matched normal tissues gathered from the Oncomine platform. We validated these results by protein expression study of all EPHs family members by The Human Protein Atlas repository. Our results uncovered the overexpression of most EPH subunits in numerous cancer types, especially the dramatic overexpression of six EPHs members, namely EPHA1, EPHA2, EPHA3, EPHA4 and EPHB1, EPHB2, EPHB3, EPHB4 in bladder, colorectal, esophageal, gastric, and prostate cancers. Furthermore, EPHB2 was specifically highly expressed in cervical cancer, EPHA3 in liver cancer, and EPHB1 in uterine cancer. Collectively, expressive profiles of these EPHs were confirmed and correlated with different cancer subtypes as potential biomarkers. This study provides useful information for further studies on cancer development and clinical treatments.
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Affiliation(s)
- Nam Nhut Phan
- NTT Institute of Hi-Technology, Nguyen Tat Thanh UniversityHo Chi Minh City 700000, Vietnam
| | - Shirui Liu
- Department of Mechanical Engineering, School of Engineering, San Francisco State UniversitySan Francisco, CA 94143, USA
- Department of Mechanical Design Manufacturing and Automation, College of Mechanical Engineering, Taiyuan University of Science and TechnologyShanxi 030024, People’s Republic of China
| | - Chih-Yang Wang
- Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung UniversityTainan 11031, Taiwan
- PhD Program for Cancer Molecular Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical UniversityTaipei 11031, Taiwan
- Graduate Institute of Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical UniversityTaipei 11031, Taiwan
| | - Hui-Ping Hsu
- Department of Surgery, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung UniversityTainan 704, Taiwan
| | - Ming-Derg Lai
- Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung UniversityTainan 11031, Taiwan
| | - Chung-Yen Li
- Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung UniversityTainan 11031, Taiwan
| | - Chien-Fu Chen
- School of Chinese Medicine for Post-Baccalaureate, I-Shou UniversityKaohsiung 84001, Taiwan
| | - Chung-Chieh Chiao
- School of Chinese Medicine for Post-Baccalaureate, I-Shou UniversityKaohsiung 84001, Taiwan
| | - Meng-Chi Yen
- Department of Emergency Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical UniversityKaohsiung 80708, Taiwan
| | - Zhengda Sun
- Department of Radiology, University of CaliforniaSan Francisco, San Francisco, CA 94143, USA
| | - Jia-Zhen Jiang
- Emergency Department, Huashan Hospital North, Fudan UniversityShanghai 201508, People’s Republic of China
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Mudd GE, Brown A, Chen L, van Rietschoten K, Watcham S, Teufel DP, Pavan S, Lani R, Huxley P, Bennett GS. Identification and Optimization of EphA2-Selective Bicycles for the Delivery of Cytotoxic Payloads. J Med Chem 2020; 63:4107-4116. [PMID: 32202781 DOI: 10.1021/acs.jmedchem.9b02129] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Bicycles are constrained bicyclic peptides that represent a promising binding modality for use in targeted drug conjugates. A phage display screen against EphA2, a receptor tyrosine kinase highly expressed in a number of solid tumors, identified a number of Bicycle families with low nanomolar affinity. A Bicycle toxin conjugate (BTC) was generated by derivatization of one of these Bicycles with the potent cytotoxin DM1 via a cleavable linker. This BTC demonstrated potent antitumor activity in vivo but was poorly tolerated, which was hypothesized to be the result of undesired liver uptake caused by poor physicochemical properties. Chemical optimization of a second Bicycle, guided by structural biology, provided a high affinity, metabolically stable Bicycle with improved physicochemical properties. A BTC incorporating this Bicycle also demonstrated potent antitumor activity and was very well tolerated when compared to the initial BTC. Phage display selection followed by chemical optimization of Bicycles can deliver potent drug conjugates with favorable pharmaceutical properties.
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Affiliation(s)
- Gemma E Mudd
- BicycleTx Limited, Building 900, Babraham Research Campus, Cambridge CB22 3AT, United Kingdom
| | - Amy Brown
- BicycleTx Limited, Building 900, Babraham Research Campus, Cambridge CB22 3AT, United Kingdom
| | - Liuhong Chen
- BicycleTx Limited, Building 900, Babraham Research Campus, Cambridge CB22 3AT, United Kingdom
| | | | - Sophie Watcham
- BicycleTx Limited, Building 900, Babraham Research Campus, Cambridge CB22 3AT, United Kingdom
| | - Daniel P Teufel
- BicycleTx Limited, Building 900, Babraham Research Campus, Cambridge CB22 3AT, United Kingdom
| | - Silvia Pavan
- BicycleTx Limited, Building 900, Babraham Research Campus, Cambridge CB22 3AT, United Kingdom
| | - Rachid Lani
- BicycleTx Limited, Building 900, Babraham Research Campus, Cambridge CB22 3AT, United Kingdom
| | - Philip Huxley
- BicycleTx Limited, Building 900, Babraham Research Campus, Cambridge CB22 3AT, United Kingdom
| | - Gavin S Bennett
- BicycleTx Limited, Building 900, Babraham Research Campus, Cambridge CB22 3AT, United Kingdom
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55
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Trenker R, Jura N. Receptor tyrosine kinase activation: From the ligand perspective. Curr Opin Cell Biol 2020; 63:174-185. [PMID: 32114309 PMCID: PMC7813211 DOI: 10.1016/j.ceb.2020.01.016] [Citation(s) in RCA: 99] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 01/27/2020] [Accepted: 01/27/2020] [Indexed: 02/06/2023]
Abstract
Receptor tyrosine kinases (RTKs) are single-span transmembrane receptors in which relatively conserved intracellular kinase domains are coupled to divergent extracellular modules. The extracellular domains initiate receptor signaling upon binding to either soluble or membrane-embedded ligands. The diversity of extracellular domain structures allows for coupling of many unique signaling inputs to intracellular tyrosine phosphorylation. The combinatorial power of this receptor system is further increased by the fact that multiple ligands can typically interact with the same receptor. Such ligands often act as biased agonists and initiate distinct signaling responses via activation of the same receptor. Mechanisms behind such biased agonism are largely unknown for RTKs, especially at the level of receptor-ligand complex structure. Using recent progress in understanding the structures of active RTK signaling units, we discuss selected mechanisms by which ligands couple receptor activation to distinct signaling outputs.
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Affiliation(s)
- Raphael Trenker
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, 94158, USA
| | - Natalia Jura
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, 94158, USA; Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA, 94158, USA.
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56
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Rozbesky D, Jones EY. Cell guidance ligands, receptors and complexes - orchestrating signalling in time and space. Curr Opin Struct Biol 2020; 61:79-85. [PMID: 31862615 PMCID: PMC7171467 DOI: 10.1016/j.sbi.2019.11.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 11/15/2019] [Indexed: 01/28/2023]
Abstract
Members of four cell guidance molecule families (the netrins, slits, ephrins and semaphorins) interact with their cognate cell surface receptors to guide cells during development and maintain tissue homeostasis. Integrated structure and cell-based analyses are providing insight into the mechanisms by which these signalling systems can deliver myriad outcomes that require exquisite accuracy in timing and location. Here we review recent advances in our understanding of the roles of oligomeric states, auto-inhibition, signalling assembly size and composition in cell guidance cue function.
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Affiliation(s)
- Daniel Rozbesky
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford, OX3 7BN, United Kingdom
| | - Edith Yvonne Jones
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford, OX3 7BN, United Kingdom.
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57
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Wagner MJ, Hsiung MS, Gish GD, Bagshaw RD, Doodnauth SA, Soliman MA, Jørgensen C, Tucholska M, Rottapel R. The Shb scaffold binds the Nck adaptor protein, p120 RasGAP, and Chimaerins and thereby facilitates heterotypic cell segregation by the receptor EphB2. J Biol Chem 2020; 295:3932-3944. [PMID: 32060095 PMCID: PMC7086039 DOI: 10.1074/jbc.ra119.009276] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 02/07/2020] [Indexed: 11/06/2022] Open
Abstract
Eph receptors are a family of receptor tyrosine kinases that control directional cell movement during various biological processes, including embryogenesis, neuronal pathfinding, and tumor formation. The biochemical pathways of Eph receptors are context-dependent in part because of the varied composition of a heterotypic, oligomeric, active Eph receptor complex. Downstream of the Eph receptors, little is known about the essential phosphorylation events that define the context and instruct cell movement. Here, we define a pathway that is required for Eph receptor B2 (EphB2)-mediated cell sorting and is conserved among multiple Eph receptors. Utilizing a HEK293 model of EphB2+/ephrinB1+ cell segregation, we found that the scaffold adaptor protein SH2 domain-containing adaptor protein B (Shb) is essential for EphB2 functionality. Further characterization revealed that Shb interacts with known modulators of cytoskeletal rearrangement and cell mobility, including Nck adaptor protein (Nck), p120-Ras GTPase-activating protein (RasGAP), and the α- and β-Chimaerin Rac GAPs. We noted that phosphorylation of Tyr297, Tyr246, and Tyr336 of Shb is required for EphB2-ephrinB1 boundary formation, as well as binding of Nck, RasGAP, and the chimaerins, respectively. Similar complexes were formed in the context of EphA4, EphA8, EphB2, and EphB4 receptor activation. These results indicate that phosphotyrosine-mediated signaling through Shb is essential in EphB2-mediated heterotypic cell segregation and suggest a conserved function for Shb downstream of multiple Eph receptors.
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Affiliation(s)
- Melany J Wagner
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario M5S 1A8, Canada
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario M5G 1X5, Canada
| | - Marilyn S Hsiung
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario M5G 1X5, Canada
| | - Gerald D Gish
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario M5G 1X5, Canada
| | - Rick D Bagshaw
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario M5G 1X5, Canada
| | - Sasha A Doodnauth
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario M5S 1A8, Canada
| | - Mohamed A Soliman
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario M5G 1X5, Canada
| | - Claus Jørgensen
- Cancer Research UK Manchester Institute, University of Manchester, Alderley Park SK10 4TG, United Kingdom
| | - Monika Tucholska
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario M5G 1X5, Canada
| | - Robert Rottapel
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario M5S 1A8, Canada
- Departments of Medicine, Immunology and Medical Biophysics, University of Toronto, Toronto, Ontario M5S, Canada
- Division of Rheumatology, St. Michael's Hospital, Toronto, Ontario M5B 1W8, Canada
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58
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Quantitative phosphoproteomic analysis identifies the potential therapeutic target EphA2 for overcoming sorafenib resistance in hepatocellular carcinoma cells. Exp Mol Med 2020; 52:497-513. [PMID: 32203105 PMCID: PMC7156679 DOI: 10.1038/s12276-020-0404-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 10/24/2019] [Accepted: 02/05/2020] [Indexed: 12/22/2022] Open
Abstract
Limited therapeutic options are available for advanced-stage hepatocellular carcinoma owing to its poor diagnosis. Drug resistance to sorafenib, the only available targeted agent, is commonly reported. The comprehensive elucidation of the mechanisms underlying sorafenib resistance may thus aid in the development of more efficacious therapeutic agents. To clarify the signaling changes contributing to resistance, we applied quantitative phosphoproteomics to analyze the differential phosphorylation changes between parental and sorafenib-resistant HuH-7 cells. Consequently, an average of ~1500 differential phosphoproteins were identified and quantified, among which 533 were significantly upregulated in resistant cells. Further bioinformatic integration via functional categorization annotation, pathway enrichment and interaction linkage analysis led to the discovery of alterations in pathways associated with cell adhesion and motility, cell survival and cell growth and the identification of a novel target, EphA2, in resistant HuH-7R cells. In vitro functional analysis indicated that the suppression of EphA2 function impairs cell proliferation and motility and, most importantly, overcomes sorafenib resistance. The attenuation of sorafenib resistance may be achieved prior to its development through the modulation of EphA2 and the subsequent inhibition of Akt activity. Binding analyses and in silico modeling revealed a ligand mimic lead compound, prazosin, that could abate the ligand-independent oncogenic activity of EphA2. Finally, data obtained from in vivo animal models verified that the simultaneous inhibition of EphA2 with sorafenib treatment can effectively overcome sorafenib resistance and extend the projected survival of resistant tumor-bearing mice. Thus our findings regarding the targeting of EphA2 may provide an effective approach for overcoming sorafenib resistance and may contribute to the management of advanced hepatocellular carcinoma.
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59
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Ricci B, Millner TO, Pomella N, Zhang X, Guglielmi L, Badodi S, Ceric D, Gemma C, Cognolato E, Zhang Y, Brandner S, Barnes MR, Marino S. Polycomb-mediated repression of EphrinA5 promotes growth and invasion of glioblastoma. Oncogene 2020; 39:2523-2538. [PMID: 31988455 PMCID: PMC7082224 DOI: 10.1038/s41388-020-1161-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 12/04/2019] [Accepted: 01/15/2020] [Indexed: 11/22/2022]
Abstract
Glioblastoma (GBM) is the most common and most aggressive intrinsic brain tumour in adults. Integrated transcriptomic and epigenomic analyses of glioblastoma initiating cells (GIC) in a mouse model uncovered a novel epigenetic regulation of EfnA5. In this model, Bmi1 enhances H3K27me3 at the EfnA5 locus and reinforces repression of selected target genes in a cellular context-dependent fashion. EfnA5 mediates Bmi1-dependent proliferation and invasion in vitro and tumour formation in an allograft model. Importantly, we show that this novel Polycomb feed-forward loop is also active in human GIC and we provide pre-clinical evidence of druggability of the EFNA5 signalling pathway in GBM xenografts overexpressing Bmi1.
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Affiliation(s)
- Barbara Ricci
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London, E1 2AT, UK
| | - Thomas O Millner
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London, E1 2AT, UK
| | - Nicola Pomella
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London, E1 2AT, UK
| | - Xinyu Zhang
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London, E1 2AT, UK
| | - Loredana Guglielmi
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London, E1 2AT, UK
| | - Sara Badodi
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London, E1 2AT, UK
| | - Dario Ceric
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London, E1 2AT, UK
| | - Carolina Gemma
- Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital Campus, London, W12 0NN, UK
| | - Erica Cognolato
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London, E1 2AT, UK
| | - Ying Zhang
- Division of Neuropathology, The National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Foundation Trust, Queen Square, London, WC1N 3BG, UK
| | - Sebastian Brandner
- Division of Neuropathology, The National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Foundation Trust, Queen Square, London, WC1N 3BG, UK
| | - Michael R Barnes
- Centre for Translational Bioinformatics, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, EC1M 6BQ, UK
| | - Silvia Marino
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London, E1 2AT, UK.
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60
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Darling TK, Mimche PN, Bray C, Umaru B, Brady LM, Stone C, Eboumbou Moukoko CE, Lane TE, Ayong LS, Lamb TJ. EphA2 contributes to disruption of the blood-brain barrier in cerebral malaria. PLoS Pathog 2020; 16:e1008261. [PMID: 31999807 PMCID: PMC6991964 DOI: 10.1371/journal.ppat.1008261] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 12/07/2019] [Indexed: 01/01/2023] Open
Abstract
Disruption of blood-brain barrier (BBB) function is a key feature of cerebral malaria. Increased barrier permeability occurs due to disassembly of tight and adherens junctions between endothelial cells, yet the mechanisms governing junction disassembly and vascular permeability during cerebral malaria remain poorly characterized. We found that EphA2 is a principal receptor tyrosine kinase mediating BBB breakdown during Plasmodium infection. Upregulated on brain microvascular endothelial cells in response to inflammatory cytokines, EphA2 is required for the loss of junction proteins on mouse and human brain microvascular endothelial cells. Furthermore, EphA2 is necessary for CD8+ T cell brain infiltration and subsequent BBB breakdown in a mouse model of cerebral malaria. Blocking EphA2 protects against BBB breakdown highlighting EphA2 as a potential therapeutic target for cerebral malaria.
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Affiliation(s)
- Thayer K. Darling
- Department of Pathology, University of Utah, Salt Lake City, UT, United States of America
- Department of Pediatric Infectious Diseases, Emory University School of Medicine, Atlanta, GA, United States of America
| | - Patrice N. Mimche
- Department of Pathology, University of Utah, Salt Lake City, UT, United States of America
| | - Christian Bray
- Department of Pediatric Infectious Diseases, Emory University School of Medicine, Atlanta, GA, United States of America
| | - Banlanjo Umaru
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroon
| | - Lauren M. Brady
- Department of Pediatric Infectious Diseases, Emory University School of Medicine, Atlanta, GA, United States of America
| | - Colleen Stone
- Department of Pathology, University of Utah, Salt Lake City, UT, United States of America
| | - Carole Else Eboumbou Moukoko
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroon
- Department of Biological Sciences, University of Douala, Douala, Cameroon
| | - Thomas E. Lane
- Department of Pathology, University of Utah, Salt Lake City, UT, United States of America
| | - Lawrence S. Ayong
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroon
| | - Tracey J. Lamb
- Department of Pathology, University of Utah, Salt Lake City, UT, United States of America
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61
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Westerfield JM, Barrera FN. Membrane receptor activation mechanisms and transmembrane peptide tools to elucidate them. J Biol Chem 2019; 295:1792-1814. [PMID: 31879273 DOI: 10.1074/jbc.rev119.009457] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Single-pass membrane receptors contain extracellular domains that respond to external stimuli and transmit information to intracellular domains through a single transmembrane (TM) α-helix. Because membrane receptors have various roles in homeostasis, signaling malfunctions of these receptors can cause disease. Despite their importance, there is still much to be understood mechanistically about how single-pass receptors are activated. In general, single-pass receptors respond to extracellular stimuli via alterations in their oligomeric state. The details of this process are still the focus of intense study, and several lines of evidence indicate that the TM domain (TMD) of the receptor plays a central role. We discuss three major mechanistic hypotheses for receptor activation: ligand-induced dimerization, ligand-induced rotation, and receptor clustering. Recent observations suggest that receptors can use a combination of these activation mechanisms and that technical limitations can bias interpretation. Short peptides derived from receptor TMDs, which can be identified by screening or rationally developed on the basis of the structure or sequence of their targets, have provided critical insights into receptor function. Here, we explore recent evidence that, depending on the target receptor, TMD peptides cannot only inhibit but also activate target receptors and can accommodate novel, bifunctional designs. Furthermore, we call for more sharing of negative results to inform the TMD peptide field, which is rapidly transforming into a suite of unique tools with the potential for future therapeutics.
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Affiliation(s)
- Justin M Westerfield
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee 37996
| | - Francisco N Barrera
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee 37996.
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62
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The endosomal sorting adaptor HD-PTP is required for ephrin-B:EphB signalling in cellular collapse and spinal motor axon guidance. Sci Rep 2019; 9:11945. [PMID: 31420572 PMCID: PMC6697728 DOI: 10.1038/s41598-019-48421-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 08/02/2019] [Indexed: 12/25/2022] Open
Abstract
The signalling output of many transmembrane receptors that mediate cell-cell communication is restricted by the endosomal sorting complex required for transport (ESCRT), but the impact of this machinery on Eph tyrosine kinase receptor function is unknown. We identified the ESCRT-associated adaptor protein HD-PTP as part of an EphB2 proximity-dependent biotin identification (BioID) interactome, and confirmed this association using co-immunoprecipitation. HD-PTP loss attenuates the ephrin-B2:EphB2 signalling-induced collapse of cultured cells and axonal growth cones, and results in aberrant guidance of chick spinal motor neuron axons in vivo. HD-PTP depletion abrogates ephrin-B2-induced EphB2 clustering, and EphB2 and Src family kinase activation. HD-PTP loss also accelerates ligand-induced EphB2 degradation, contrasting the effects of HD-PTP loss on the relay of signals from other cell surface receptors. Our results link Eph function to the ESCRT machinery and demonstrate a role for HD-PTP in the earliest steps of ephrin-B:EphB signalling, as well as in obstructing premature receptor depletion.
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63
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Liang LY, Patel O, Janes PW, Murphy JM, Lucet IS. Eph receptor signalling: from catalytic to non-catalytic functions. Oncogene 2019; 38:6567-6584. [PMID: 31406248 DOI: 10.1038/s41388-019-0931-2] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 07/23/2019] [Accepted: 07/24/2019] [Indexed: 12/26/2022]
Abstract
Eph receptors, the largest subfamily of receptor tyrosine kinases, are linked with proliferative disease, such as cancer, as a result of their deregulated expression or mutation. Unlike other tyrosine kinases that have been clinically targeted, the development of therapeutics against Eph receptors remains at a relatively early stage. The major reason is the limited understanding on the Eph receptor regulatory mechanisms at a molecular level. The complexity in understanding Eph signalling in cells arises due to following reasons: (1) Eph receptors comprise 14 members, two of which are pseudokinases, EphA10 and EphB6, with relatively uncharacterised function; (2) activation of Eph receptors results in dimerisation, oligomerisation and formation of clustered signalling centres at the plasma membrane, which can comprise different combinations of Eph receptors, leading to diverse downstream signalling outputs; (3) the non-catalytic functions of Eph receptors have been overlooked. This review provides a structural perspective of the intricate molecular mechanisms that drive Eph receptor signalling, and investigates the contribution of intra- and inter-molecular interactions between Eph receptors intracellular domains and their major binding partners. We focus on the non-catalytic functions of Eph receptors with relevance to cancer, which are further substantiated by exploring the role of the two pseudokinase Eph receptors, EphA10 and EphB6. Throughout this review, we carefully analyse and reconcile the existing/conflicting data in the field, to allow researchers to further the current understanding of Eph receptor signalling.
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Affiliation(s)
- Lung-Yu Liang
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia.,Department of Medical Biology, University of Melbourne, Parkville, VIC, 3052, Australia
| | - Onisha Patel
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia.,Department of Medical Biology, University of Melbourne, Parkville, VIC, 3052, Australia
| | - Peter W Janes
- Olivia Newton-John Cancer Research Institute, 145 Studley Road, Heidelberg, VIC, 3084, Australia
| | - James M Murphy
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia. .,Department of Medical Biology, University of Melbourne, Parkville, VIC, 3052, Australia.
| | - Isabelle S Lucet
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia. .,Department of Medical Biology, University of Melbourne, Parkville, VIC, 3052, Australia.
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64
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Darling TK, Lamb TJ. Emerging Roles for Eph Receptors and Ephrin Ligands in Immunity. Front Immunol 2019; 10:1473. [PMID: 31333644 PMCID: PMC6620610 DOI: 10.3389/fimmu.2019.01473] [Citation(s) in RCA: 141] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 06/13/2019] [Indexed: 12/30/2022] Open
Abstract
Eph receptors are the largest family of receptor tyrosine kinases and mediate a myriad of essential processes in humans from embryonic development to adult tissue homeostasis through interactions with membrane-bound ephrin ligands. The ubiquitous expression of Eph receptors and ephrin ligands among the cellular players of the immune system underscores the importance of these molecules in orchestrating an optimal immune response. This review provides an overview of the various roles of Eph receptors and ephrin ligands in immune cell development, activation, and migration. We also discuss the role of Eph receptors in disease pathogenesis as well as the implications of Eph receptors as future immunotherapy targets. Given the diverse and critical roles of Eph receptors and ephrin ligands throughout the immune system during both resting and activated states, this review aims to highlight the critical yet underappreciated roles of this family of signaling molecules in the immune system.
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Affiliation(s)
- Thayer K Darling
- Immunology and Molecular Pathogenesis Program, Emory University Laney Graduate School, Atlanta, GA, United States.,Department of Pathology, University of Utah, Salt Lake City, UT, United States
| | - Tracey J Lamb
- Department of Pathology, University of Utah, Salt Lake City, UT, United States
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65
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Agarwal G, Smith AW, Jones B. Discoidin domain receptors: Micro insights into macro assemblies. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2019; 1866:118496. [PMID: 31229648 DOI: 10.1016/j.bbamcr.2019.06.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 06/12/2019] [Accepted: 06/13/2019] [Indexed: 12/19/2022]
Abstract
Assembly of cell-surface receptors into specific oligomeric states and/or clusters before and after ligand binding is an important feature governing their biological function. Receptor oligomerization can be mediated by specific domains of the receptor, ligand binding, configurational changes or other interacting molecules. In this review we summarize our understanding of the oligomeric state of discoidin domain receptors (DDR1 and DDR2), which belong to the receptor tyrosine kinase family (RTK). DDRs form an interesting system from an oligomerization perspective as their ligand collagen(s) can also undergo supramolecular assembly to form fibrils. Even though DDR1 and DDR2 differ in the domains responsible to form ligand-free dimers they share similarities in binding to soluble, monomeric collagen. However, only DDR1b forms globular clusters in response to monomeric collagen and not DDR2. Interestingly, both DDR1 and DDR2 are assembled into linear clusters by the collagen fibril. Formation of these clusters is important for receptor phosphorylation and is mediated in part by other membrane components. We summarize how the oligomeric status of DDRs shares similarities with other members of the RTK family and with collagen receptors. Unraveling the multiple macro-molecular configurations adopted by this receptor-ligand pair can provide novel insights into the intricacies of cell-matrix interactions.
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Affiliation(s)
- Gunjan Agarwal
- Biomedical Engineering Department, The Ohio State University, Columbus, OH 43210, USA.
| | - Adam W Smith
- Department of Chemistry, University of Akron, Akron, OH 44325, USA
| | - Blain Jones
- Biomedical Engineering Department, The Ohio State University, Columbus, OH 43210, USA
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66
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Cross-Talk between Fibroblast Growth Factor Receptors and Other Cell Surface Proteins. Cells 2019; 8:cells8050455. [PMID: 31091809 PMCID: PMC6562592 DOI: 10.3390/cells8050455] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 05/08/2019] [Accepted: 05/13/2019] [Indexed: 12/14/2022] Open
Abstract
Fibroblast growth factors (FGFs) and their receptors (FGFRs) constitute signaling circuits that transmit signals across the plasma membrane, regulating pivotal cellular processes like differentiation, migration, proliferation, and apoptosis. The malfunction of FGFs/FGFRs signaling axis is observed in numerous developmental and metabolic disorders, and in various tumors. The large diversity of FGFs/FGFRs functions is attributed to a great complexity in the regulation of FGFs/FGFRs-dependent signaling cascades. The function of FGFRs is modulated at several levels, including gene expression, alternative splicing, posttranslational modifications, and protein trafficking. One of the emerging ways to adjust FGFRs activity is through formation of complexes with other integral proteins of the cell membrane. These proteins may act as coreceptors, modulating binding of FGFs to FGFRs and defining specificity of elicited cellular response. FGFRs may interact with other cell surface receptors, like G-protein-coupled receptors (GPCRs) or receptor tyrosine kinases (RTKs). The cross-talk between various receptors modulates the strength and specificity of intracellular signaling and cell fate. At the cell surface FGFRs can assemble into large complexes involving various cell adhesion molecules (CAMs). The interplay between FGFRs and CAMs affects cell–cell interaction and motility and is especially important for development of the central nervous system. This review summarizes current stage of knowledge about the regulation of FGFRs by the plasma membrane-embedded partner proteins and highlights the importance of FGFRs-containing membrane complexes in pathological conditions, including cancer.
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67
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Abstract
A wide range of cell–microenvironmental interactions are mediated by membrane-localized receptors that bind ligands present on another cell or the extracellular matrix. This situation introduces a number of physical effects including spatial organization of receptor–ligand complexes and development of mechanical forces in cells. Unlike traditional experimental approaches, hybrid live cell–supported lipid bilayer (SLB) systems, wherein a live cell interacts with a synthetic substrate supported membrane, allow interrogation of these aspects of receptor signaling. The SLB system directly offers facile control over the identity, density, and mobility of ligands used for engaging cellular receptors. Further, application of various nano- and micropatterning techniques allows for spatial patterning of ligands. In this review, we describe the hybrid live cell–SLB system and its application in uncovering a range of spatial and mechanical aspects of receptor signaling. We highlight the T cell immunological synapse, junctions formed between EphA2- and ephrinA1-expressing cells, and adhesions formed by cadherin and integrin receptors.
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Affiliation(s)
- Kabir H. Biswas
- NTU Institute for Health Technologies, Nanyang Technological University, Singapore 637553
| | - Jay T. Groves
- Department of Chemistry, University of California, Berkeley, California 94720, USA
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68
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Krishnan A, Degnan BM, Degnan SM. The first identification of complete Eph-ephrin signalling in ctenophores and sponges reveals a role for neofunctionalization in the emergence of signalling domains. BMC Evol Biol 2019; 19:96. [PMID: 31023220 PMCID: PMC6485061 DOI: 10.1186/s12862-019-1418-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 03/31/2019] [Indexed: 11/25/2022] Open
Abstract
Background Animals have a greater diversity of signalling pathways than their unicellular relatives, consistent with the evolution and expansion of these pathways occurring in parallel with the origin of animal multicellularity. However, the genomes of sponges and ctenophores – non-bilaterian basal animals – typically encode no, or far fewer, recognisable signalling ligands compared to bilaterians and cnidarians. For instance, the largest subclass of receptor tyrosine kinases (RTKs) in bilaterians, the Eph receptors (Ephs), are present in sponges and ctenophores, but their cognate ligands, the ephrins, have not yet been detected. Results Here, we use an iterative HMM analysis to identify for the first time membrane-bound ephrins in sponges and ctenophores. We also expand the number of Eph-receptor subtypes identified in these animals and in cnidarians. Both sequence and structural analyses are consistent with the Eph ligand binding domain (LBD) and the ephrin receptor binding domain (RBD) having evolved via the co-option of ancient galactose-binding (discoidin-domain)-like and monodomain cupredoxin domains, respectively. Although we did not detect a complete Eph-ephrin signalling pathway in closely-related unicellular holozoans or in other non-metazoan eukaryotes, truncated proteins with Eph receptor LBDs and ephrin RBDs are present in some choanoflagellates. Together, these results indicate that Eph-ephrin signalling was present in the last common ancestor of extant metazoans, and perhaps even in the last common ancestor of animals and choanoflagellates. Either scenario pushes the origin of Eph-ephrin signalling back much earlier than previously reported. Conclusions We propose that the Eph-LBD and ephrin-RBD, which were ancestrally localised in the cytosol, became linked to the extracellular parts of two cell surface proteins before the divergence of sponges and ctenophores from the rest of the animal kingdom. The ephrin-RBD lost the ancestral capacity to bind copper, and the Eph-LBD became linked to an ancient RTK. The identification of divergent ephrin ligands in sponges and ctenophores suggests that these ligands evolve faster than their cognate receptors. As this may be a general phenomena, we propose that the sequence-structure approach used in this study may be usefully applied to other signalling systems where no, or a small number of, ligands have been identified. Electronic supplementary material The online version of this article (10.1186/s12862-019-1418-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Arunkumar Krishnan
- School of Biological Sciences, The University of Queensland, Brisbane, Queensland, Australia.,Present Address: National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD, 20894, USA
| | - Bernard M Degnan
- School of Biological Sciences, The University of Queensland, Brisbane, Queensland, Australia
| | - Sandie M Degnan
- School of Biological Sciences, The University of Queensland, Brisbane, Queensland, Australia.
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69
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Gomez-Soler M, Petersen Gehring M, Lechtenberg BC, Zapata-Mercado E, Hristova K, Pasquale EB. Engineering nanomolar peptide ligands that differentially modulate EphA2 receptor signaling. J Biol Chem 2019; 294:8791-8805. [PMID: 31015204 DOI: 10.1074/jbc.ra119.008213] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 04/18/2019] [Indexed: 11/06/2022] Open
Abstract
The EPH receptor A2 (EphA2) tyrosine kinase plays an important role in a plethora of biological and disease processes, ranging from angiogenesis and cancer to inflammation and parasitic infections. EphA2 is therefore considered an important drug target. Two short peptides previously identified by phage display, named YSA and SWL, are widely used as EphA2-targeting agents owing to their high specificity for this receptor. However, these peptides have only modest (micromolar) potency. Lack of structural information on the binding interactions of YSA and SWL with the extracellular EphA2 ligand-binding domain (LBD) has for many years precluded structure-guided improvements. We now report the high-resolution (1.53-2.20 Å) crystal structures of the YSA peptide and several of its improved derivatives in complex with the EphA2 LBD, disclosing that YSA targets the ephrin-binding pocket of EphA2 and mimics binding features of the ephrin-A ligands. The structural information obtained enabled iterative peptide modifications conferring low nanomolar potency. Furthermore, contacts observed in the crystal structures shed light on how C-terminal features can convert YSA derivatives from antagonists to agonists that likely bivalently interact with two EphA2 molecules to promote receptor oligomerization, autophosphorylation, and downstream signaling. Consistent with this model, quantitative FRET measurements in live cells revealed that the peptide agonists promote the formation of EphA2 oligomeric assemblies. Our findings now enable rational strategies to differentially modify EphA2 signaling toward desired outcomes by using appropriately engineered peptides. Such peptides could be used as research tools to interrogate EphA2 function and to develop pharmacological leads.
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Affiliation(s)
- Maricel Gomez-Soler
- From the Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California 92037 and
| | - Marina Petersen Gehring
- From the Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California 92037 and
| | - Bernhard C Lechtenberg
- From the Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California 92037 and
| | - Elmer Zapata-Mercado
- the Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland 21218
| | - Kalina Hristova
- the Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland 21218
| | - Elena B Pasquale
- From the Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California 92037 and
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70
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Abstract
Cell surface transmembrane receptors often form nanometer- to micrometer-scale clusters to initiate signal transduction in response to environmental cues. Extracellular ligand oligomerization, domain-domain interactions, and binding to multivalent proteins all contribute to cluster formation. Here we review the current understanding of mechanisms driving cluster formation in a series of representative receptor systems: glycosylated receptors, immune receptors, cell adhesion receptors, Wnt receptors, and receptor tyrosine kinases. We suggest that these clusters share properties of systems that undergo liquid-liquid phase separation and could be investigated in this light.
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Affiliation(s)
- Lindsay B Case
- Department of Biophysics and Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA; , ,
| | - Jonathon A Ditlev
- Department of Biophysics and Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA; , ,
| | - Michael K Rosen
- Department of Biophysics and Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA; , ,
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71
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Niethamer TK, Bush JO. Getting direction(s): The Eph/ephrin signaling system in cell positioning. Dev Biol 2019; 447:42-57. [PMID: 29360434 PMCID: PMC6066467 DOI: 10.1016/j.ydbio.2018.01.012] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 12/21/2017] [Accepted: 01/18/2018] [Indexed: 12/16/2022]
Abstract
In vertebrates, the Eph/ephrin family of signaling molecules is a large group of membrane-bound proteins that signal through a myriad of mechanisms and effectors to play diverse roles in almost every tissue and organ system. Though Eph/ephrin signaling has functions in diverse biological processes, one core developmental function is in the regulation of cell position and tissue morphology by regulating cell migration and guidance, cell segregation, and boundary formation. Often, the role of Eph/ephrin signaling is to translate patterning information into physical movement of cells and changes in morphology that define tissue and organ systems. In this review, we focus on recent advances in the regulation of these processes, and our evolving understanding of the in vivo signaling mechanisms utilized in distinct developmental contexts.
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Affiliation(s)
- Terren K Niethamer
- Department of Cell and Tissue Biology, Program in Craniofacial Biology, and Institute of Human Genetics, University of California at San Francisco, San Francisco, CA 94143, USA
| | - Jeffrey O Bush
- Department of Cell and Tissue Biology, Program in Craniofacial Biology, and Institute of Human Genetics, University of California at San Francisco, San Francisco, CA 94143, USA.
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72
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Zeng X, Hunt A, Jin SC, Duran D, Gaillard J, Kahle KT. EphrinB2-EphB4-RASA1 Signaling in Human Cerebrovascular Development and Disease. Trends Mol Med 2019; 25:265-286. [PMID: 30819650 DOI: 10.1016/j.molmed.2019.01.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 01/17/2019] [Accepted: 01/29/2019] [Indexed: 12/13/2022]
Abstract
Recent whole exome sequencing studies in humans have provided novel insight into the importance of the ephrinB2-EphB4-RASA1 signaling axis in cerebrovascular development, corroborating and extending previous work in model systems. Here, we aim to review the human cerebrovascular phenotypes associated with ephrinB2-EphB4-RASA1 mutations, including those recently discovered in Vein of Galen malformation: the most common and severe brain arteriovenous malformation in neonates. We will also discuss emerging paradigms of the molecular and cellular pathophysiology of disease-causing ephrinB2-EphB4-RASA1 mutations, including the potential role of somatic mosaicism. These observations have potential diagnostic and therapeutic implications for patients with rare congenital cerebrovascular diseases and their families.
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Affiliation(s)
- Xue Zeng
- Department of Genetics, Yale School of Medicine, New Haven CT, USA; Laboratory of Human Genetics and Genomics, The Rockefeller University, New York, NY, USA
| | - Ava Hunt
- Department of Neurosurgery, Yale School of Medicine, New Haven CT, USA
| | - Sheng Chih Jin
- Laboratory of Human Genetics and Genomics, The Rockefeller University, New York, NY, USA
| | - Daniel Duran
- Department of Neurosurgery, Yale School of Medicine, New Haven CT, USA
| | - Jonathan Gaillard
- Department of Neurosurgery, Yale School of Medicine, New Haven CT, USA
| | - Kristopher T Kahle
- Department of Neurosurgery, Yale School of Medicine, New Haven CT, USA; Department of Pediatrics, Yale School of Medicine, New Haven CT, USA; Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven CT, USA.
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73
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Won SY, Lee P, Kim HM. Synaptic organizer: Slitrks and type IIa receptor protein tyrosine phosphatases. Curr Opin Struct Biol 2019; 54:95-103. [PMID: 30822649 DOI: 10.1016/j.sbi.2019.01.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 01/24/2019] [Accepted: 01/28/2019] [Indexed: 10/27/2022]
Abstract
Slit-like and Trk-like (Slitrk) family members are leucine-rich repeat (LRR)-containing neuronal transmembrane proteins. Slitrks have been highlighted as key synapse organizers at neuronal synapses through interactions with specific members of the presynaptic type IIa receptor protein tyrosine phosphatase (RPTP) family. Recent structural studies on type IIa RPTP/Slitrk1 complexes have unveiled molecular insights into their binding selectivity and have established the role of higher-order receptor clustering in their synaptogenic activity. Here, we will discuss key structural aspects of Slitrk interactions with type IIa RPTP family members, the biological roles of Slitrks in neurons, and our current knowledge of SLITRK mutations in human diseases.
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Affiliation(s)
- Seoung Youn Won
- Graduate School of Medical Science & Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Pedro Lee
- Graduate School of Medical Science & Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Ho Min Kim
- Graduate School of Medical Science & Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea; Center for Biomolecular & Cellular Structure, Institute for Basic Science (IBS), Daejeon, Republic of Korea.
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74
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Möser C, Lorenz JS, Sajfutdinow M, Smith DM. Pinpointed Stimulation of EphA2 Receptors via DNA-Templated Oligovalence. Int J Mol Sci 2018; 19:ijms19113482. [PMID: 30404153 PMCID: PMC6274923 DOI: 10.3390/ijms19113482] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 11/02/2018] [Indexed: 11/20/2022] Open
Abstract
DNA nanostructures enable the attachment of functional molecules to nearly any unique location on their underlying structure. Due to their single-base-pair structural resolution, several ligands can be spatially arranged and closely controlled according to the geometry of their desired target, resulting in optimized binding and/or signaling interactions. Here, the efficacy of SWL, an ephrin-mimicking peptide that binds specifically to EphrinA2 (EphA2) receptors, increased by presenting up to three of these peptides on small DNA nanostructures in an oligovalent manner. Ephrin signaling pathways play crucial roles in tumor development and progression. Moreover, Eph receptors are potential targets in cancer diagnosis and treatment. Here, the quantitative impact of SWL valency on binding, phosphorylation (key player for activation) and phenotype regulation in EphA2-expressing prostate cancer cells was demonstrated. EphA2 phosphorylation was significantly increased by DNA trimers carrying three SWL peptides compared to monovalent SWL. In comparison to one of EphA2’s natural ligands ephrin-A1, which is known to bind promiscuously to multiple receptors, pinpointed targeting of EphA2 by oligovalent DNA-SWL constructs showed enhanced cell retraction. Overall, we show that DNA scaffolds can increase the potency of weak signaling peptides through oligovalent presentation and serve as potential tools for examination of complex signaling pathways.
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Affiliation(s)
- Christin Möser
- DNA Nanodevices Unit, Department Diagnostics, Fraunhofer Institute for Cell Therapy and Immunology IZI, 04103 Leipzig, Germany.
- Institute of Biochemistry and Biology, Faculty of Science, University of Potsdam, 14476 Potsdam, Germany.
| | - Jessica S Lorenz
- DNA Nanodevices Unit, Department Diagnostics, Fraunhofer Institute for Cell Therapy and Immunology IZI, 04103 Leipzig, Germany.
- Peter Debye Institute for Soft Matter Physics, Faculty of Physics and Earth Sciences, University of Leipzig, 04103 Leipzig, Germany.
| | - Martin Sajfutdinow
- DNA Nanodevices Unit, Department Diagnostics, Fraunhofer Institute for Cell Therapy and Immunology IZI, 04103 Leipzig, Germany.
- Fraunhofer Project Center "Microelectronic and Optical Systems for Biomedicine" (MEOS), 99099 Erfurt, Germany.
| | - David M Smith
- DNA Nanodevices Unit, Department Diagnostics, Fraunhofer Institute for Cell Therapy and Immunology IZI, 04103 Leipzig, Germany.
- Peter Debye Institute for Soft Matter Physics, Faculty of Physics and Earth Sciences, University of Leipzig, 04103 Leipzig, Germany.
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75
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Alves DS, Westerfield JM, Shi X, Nguyen VP, Stefanski KM, Booth KR, Kim S, Morrell-Falvey J, Wang BC, Abel SM, Smith AW, Barrera FN. A novel pH-dependent membrane peptide that binds to EphA2 and inhibits cell migration. eLife 2018; 7:36645. [PMID: 30222105 PMCID: PMC6192698 DOI: 10.7554/elife.36645] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 09/16/2018] [Indexed: 12/19/2022] Open
Abstract
Misregulation of the signaling axis formed by the receptor tyrosine kinase (RTK) EphA2 and its ligand, ephrinA1, causes aberrant cell-cell contacts that contribute to metastasis. Solid tumors are characterized by an acidic extracellular medium. We intend to take advantage of this tumor feature to design new molecules that specifically target tumors. We created a novel pH-dependent transmembrane peptide, TYPE7, by altering the sequence of the transmembrane domain of EphA2. TYPE7 is highly soluble and interacts with the surface of lipid membranes at neutral pH, while acidity triggers transmembrane insertion. TYPE7 binds to endogenous EphA2 and reduces Akt phosphorylation and cell migration as effectively as ephrinA1. Interestingly, we found large differences in juxtamembrane tyrosine phosphorylation and the extent of EphA2 clustering when comparing TYPE7 with activation by ephrinA1. This work shows that it is possible to design new pH-triggered membrane peptides to activate RTK and gain insights on its activation mechanism.
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Affiliation(s)
- Daiane S Alves
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, United States
| | - Justin M Westerfield
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, United States
| | - Xiaojun Shi
- Department of Chemistry, University of Akron, Akron, United States.,Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, United States.,Pharmacology, Case Western Reserve University, Cleveland, United States.,Rammelkamp Center for Research, MetroHealth Medical Center, Cleveland, United States
| | - Vanessa P Nguyen
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, United States
| | - Katherine M Stefanski
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, United States
| | - Kristen R Booth
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, United States
| | - Soyeon Kim
- Department of Chemistry, University of Akron, Akron, United States
| | - Jennifer Morrell-Falvey
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, United States.,Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, United States
| | - Bing-Cheng Wang
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, United States.,Pharmacology, Case Western Reserve University, Cleveland, United States.,Rammelkamp Center for Research, MetroHealth Medical Center, Cleveland, United States
| | - Steven M Abel
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, United States.,National Institute for Mathematical and Biological Synthesis, University of Tennessee, Knoxville, United States
| | - Adam W Smith
- Department of Chemistry, University of Akron, Akron, United States
| | - Francisco N Barrera
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, United States
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76
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TerBush AA, Hafkamp F, Lee HJ, Coscoy L. A Kaposi's Sarcoma-Associated Herpesvirus Infection Mechanism Is Independent of Integrins α3β1, αVβ3, and αVβ5. J Virol 2018; 92:e00803-18. [PMID: 29899108 PMCID: PMC6096800 DOI: 10.1128/jvi.00803-18] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 06/08/2018] [Indexed: 12/24/2022] Open
Abstract
Host receptor usage by Kaposi's sarcoma-associated herpesvirus (KSHV) has been best studied using primary microvascular endothelial and fibroblast cells, although the virus infects a wide variety of cell types in culture and in natural infections. In these two infection models, KSHV adheres to the cell though heparan sulfate (HS) binding and then interacts with a complex of EphA2, xCT, and integrins α3β1, αVβ3, and αVβ5 to catalyze viral entry. We dissected this receptor complex at the genetic level with CRISPR-Cas9 to precisely determine receptor usage in two epithelial cell lines. Surprisingly, we discovered an infection mechanism that requires HS and EphA2 but is independent of αV- and β1-family integrin expression. Furthermore, infection appears to be independent of the EphA2 intracellular domain. We also demonstrated that while two other endogenous Eph receptors were dispensable for KSHV infection, transduced EphA4 and EphA5 significantly enhanced infection of cells lacking EphA2.IMPORTANCE Our data reveal an integrin-independent route of KSHV infection and suggest that multiple Eph receptors besides EphA2 can promote and regulate infection. Since integrins and Eph receptors are large protein families with diverse expression patterns across cells and tissues, we propose that KSHV may engage with several proteins from both families in different combinations to negotiate successful entry into diverse cell types.
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Affiliation(s)
- Allison Alwan TerBush
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA
| | - Florianne Hafkamp
- Graduate School of Life Sciences, Utrecht University, Utrecht, Netherlands
| | - Hee Jun Lee
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA
| | - Laurent Coscoy
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA
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77
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Henderson NT, Dalva MB. EphBs and ephrin-Bs: Trans-synaptic organizers of synapse development and function. Mol Cell Neurosci 2018; 91:108-121. [PMID: 30031105 PMCID: PMC6159941 DOI: 10.1016/j.mcn.2018.07.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 07/17/2018] [Accepted: 07/18/2018] [Indexed: 12/31/2022] Open
Abstract
Synapses are specialized cell-cell junctions that underlie the function of neural circuits by mediating communication between neurons. Both the formation and function of synapses require tight coordination of signaling between pre- and post-synaptic neurons. Trans-synaptic organizing molecules are important mediators of such signaling. Here we discuss how the EphB and ephrin-B families of trans-synaptic organizing proteins direct synapse formation during early development and regulate synaptic function and plasticity at mature synapses. Finally, we highlight recent evidence linking the synaptic organizing role of EphBs and ephrin-Bs to diseases of maladaptive synaptic function and plasticity.
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Affiliation(s)
- Nathan T Henderson
- The Jefferson Synaptic Biology Center, Department of Neuroscience, The Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University, Jefferson Hospital for Neuroscience, Suite 463, 900 Walnut St., Philadelphia, PA 19107, United States
| | - Matthew B Dalva
- The Jefferson Synaptic Biology Center, Department of Neuroscience, The Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University, Jefferson Hospital for Neuroscience, Suite 463, 900 Walnut St., Philadelphia, PA 19107, United States.
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78
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Won SY, Kim HM. Structural Basis for LAR-RPTP-Mediated Synaptogenesis. Mol Cells 2018; 41:622-630. [PMID: 30008201 PMCID: PMC6078854 DOI: 10.14348/molcells.2018.0202] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 06/10/2018] [Accepted: 06/25/2018] [Indexed: 12/28/2022] Open
Abstract
Leukocyte common antigen-related protein tyrosine phosphatases (LAR-RPTPs) are cellular receptors of heparan sulfate (HS) and chondroitin sulfate (CS) proteoglycans that regulate neurite outgrowth and neuronal regeneration. LAR-RPTPs have also received particular attention as the major presynaptic hubs for synapse organization through selective binding to numerous postsynaptic adhesion partners. Recent structural studies on LAR-RPTP-mediated trans-synaptic adhesion complexes have provided significant insight into the molecular basis of their specific interactions, the key codes for their selective binding, as well as the higher-order clustering of LAR-RPTPs necessary for synaptogenic activity. In this review, we summarize the structures of LAR-RPTPs in complex with various postsynaptic adhesion partners and discuss the molecular mechanisms underlying LAR-RPTP-mediated synaptogenesis.
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Affiliation(s)
- Seoung Youn Won
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141,
Korea
| | - Ho Min Kim
- Graduate School of Medical Science & Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141,
Korea
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon 34141,
Korea
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79
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Chavent M, Karia D, Kalli AC, Domański J, Duncan AL, Hedger G, Stansfeld PJ, Seiradake E, Jones EY, Sansom MSP. Interactions of the EphA2 Kinase Domain with PIPs in Membranes: Implications for Receptor Function. Structure 2018; 26:1025-1034.e2. [PMID: 29887500 PMCID: PMC6039763 DOI: 10.1016/j.str.2018.05.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 03/15/2018] [Accepted: 05/08/2018] [Indexed: 11/29/2022]
Abstract
EphA2 is a member of the receptor tyrosine kinase family. Interactions of the cytoplasmic region of EphA2 with the cell membrane are functionally important and yet remain incompletely characterized. Molecular dynamics simulations combined with biochemical studies reveal the interactions of the transmembrane, juxtamembrane (JM), and kinase domains with the membrane. We describe how the kinase domain is oriented relative to the membrane and how the JM region can modulate this interaction. We highlight the role of phosphatidylinositol phosphates (PIPs) in mediating the interaction of the kinase domain with the membrane and, conversely, how positively charged patches at the kinase surface and in the JM region induce the formation of nanoclusters of PIP molecules in the membrane. Integration of these results with those from previous studies enable computational reconstitution of a near complete EphA2 receptor within a membrane, suggesting a role for receptor-lipid interactions in modulation of EphA2.
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Affiliation(s)
- Matthieu Chavent
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK; Institut de Pharmacologie et de Biologie Structurale IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Dimple Karia
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Antreas C Kalli
- Leeds Institute of Cancer and Pathology, St James's University Hospital, University of Leeds, Leeds, UK
| | - Jan Domański
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Anna L Duncan
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - George Hedger
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Phillip J Stansfeld
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Elena Seiradake
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - E Yvonne Jones
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Mark S P Sansom
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK.
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80
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Protein Clusters in Phosphotyrosine Signal Transduction. J Mol Biol 2018; 430:4547-4556. [PMID: 29870724 DOI: 10.1016/j.jmb.2018.05.040] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 05/08/2018] [Accepted: 05/28/2018] [Indexed: 11/20/2022]
Abstract
Signal transduction systems based on tyrosine phosphorylation are central to cell-cell communication in multicellular organisms. Typically, in such a system, the signal is initiated by activating tyrosine kinases associated with transmembrane receptors, which induces tyrosine phosphorylation of the receptor and/or associated proteins. The phosphorylated tyrosines then serve as docking sites for the binding of various downstream effector proteins. It has long been observed that the cooperative association of the receptors and effectors produces higher-order protein assemblies (clusters) following signal activation in virtually all phosphotyrosine signal transduction systems. However, mechanistic studies on how such clustering processes affect signal transduction outcomes have only emerged recently. Here we review current progress in decoding the biophysical consequences of clustering on the behavior of the system, and how clustering affects how these receptors process information.
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81
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Kou CTJ, Kandpal RP. Differential Expression Patterns of Eph Receptors and Ephrin Ligands in Human Cancers. BIOMED RESEARCH INTERNATIONAL 2018; 2018:7390104. [PMID: 29682554 PMCID: PMC5851329 DOI: 10.1155/2018/7390104] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 01/11/2018] [Accepted: 01/22/2018] [Indexed: 12/20/2022]
Abstract
Eph receptors constitute the largest family of receptor tyrosine kinases, which are activated by ephrin ligands that either are anchored to the membrane or contain a transmembrane domain. These molecules play important roles in the development of multicellular organisms, and the physiological functions of these receptor-ligand pairs have been extensively documented in axon guidance, neuronal development, vascular patterning, and inflammation during tissue injury. The recognition that aberrant regulation and expression of these molecules lead to alterations in proliferative, migratory, and invasive potential of a variety of human cancers has made them potential targets for cancer therapeutics. We present here the involvement of Eph receptors and ephrin ligands in lung carcinoma, breast carcinoma, prostate carcinoma, colorectal carcinoma, glioblastoma, and medulloblastoma. The aberrations in their abundances are described in the context of multiple signaling pathways, and differential expression is suggested as the mechanism underlying tumorigenesis.
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Affiliation(s)
- Chung-Ting Jimmy Kou
- Department of Basic Medical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Raj P. Kandpal
- Department of Basic Medical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA
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82
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The EphA2 receptor is activated through induction of distinct, ligand-dependent oligomeric structures. Commun Biol 2018; 1:15. [PMID: 30271902 PMCID: PMC6123813 DOI: 10.1038/s42003-018-0017-7] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 01/28/2018] [Indexed: 01/19/2023] Open
Abstract
The EphA2 receptor tyrosine kinase is capable of activating multiple diverse signaling pathways with roles in processes such as tissue homeostasis and cancer. EphA2 is known to form activated oligomers in the presence of ephrin-A ligands. Here, we characterize the lateral interactions between full-length EphA2 molecules in the plasma membrane in the presence of three types of ligands (dimeric ephrinA1-Fc, monomeric ephrinA1, and an engineered peptide ligand) as well as in the absence of ligand, using a quantitative FRET technique. The data show that EphA2 forms higher-order oligomers and two different types of dimers that all lead to increased EphA2 tyrosine phosphorylation, which is indicative of increased kinase-dependent signaling. We find that different ligands stabilize conformationally distinct oligomers that are assembled through two different interfaces. Our results suggest that these different oligomeric assemblies could have distinct signaling properties, contributing to the diverse activities of the EphA2 receptor. Deo Singh et al. use Fully Quantified Spectral Imaging-FRET to show that the EphA2 receptor forms dimers or higher order oligomers depending on the type of ligand, and that different ligands stabilize EphA2 dimers through distinct interfaces. These findings may explain how EphA2 activates diverse signaling pathways.
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83
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Locke C, Machida K, Tucker CL, Wu Y, Yu J. Optogenetic activation of EphB2 receptor in dendrites induced actin polymerization by activating Arg kinase. Biol Open 2017; 6:1820-1830. [PMID: 29158322 PMCID: PMC5769660 DOI: 10.1242/bio.029900] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Erythropoietin-producing hepatocellular (Eph) receptors regulate a wide array of developmental processes by responding to cell-cell contacts. EphB2 is well-expressed in the brain and known to be important for dendritic spine development, as well as for the maintenance of the synapses, although the mechanisms of these functions have not been fully understood. Here we studied EphB2's functions in hippocampal neurons with an optogenetic approach, which allowed us to specify spatial regions of signal activation and monitor in real-time the consequences of signal activation. We designed and constructed OptoEphB2, a genetically encoded photoactivatable EphB2. Photoactivation of OptoEphB2 in fibroblast cells induced receptor phosphorylation and resulted in cell rounding ------- a well-known cellular response to EphB2 activation. In contrast, local activation of OptoEphb2 in dendrites of hippocampal neurons induces rapid actin polymerization, resulting dynamic dendritic filopodial growth. Inhibition of Rac1 and CDC42 did not abolish OptoEphB2-induced actin polymerization. Instead, we identified Abelson tyrosine-protein kinase 2 (Abl2/Arg) as a necessary effector in OptoEphB2-induced filopodia growth in dendrites. These findings provided new mechanistic insight into EphB2's role in neural development and demonstrated the advantage of OptoEphB as a new tool for studying EphB signaling.
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Affiliation(s)
- Clifford Locke
- Richard D. Berlin Center for Cell Analysis and Modeling, University of Connecticut Health Center, Farmington, CT 06030, USA
| | - Kazuya Machida
- Richard D. Berlin Center for Cell Analysis and Modeling, University of Connecticut Health Center, Farmington, CT 06030, USA
| | | | - Yi Wu
- Richard D. Berlin Center for Cell Analysis and Modeling, University of Connecticut Health Center, Farmington, CT 06030, USA
| | - Ji Yu
- Richard D. Berlin Center for Cell Analysis and Modeling, University of Connecticut Health Center, Farmington, CT 06030, USA
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84
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Eph-ephrin signaling modulated by polymerization and condensation of receptors. Proc Natl Acad Sci U S A 2017; 114:13188-13193. [PMID: 29192024 DOI: 10.1073/pnas.1713564114] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Eph receptor signaling plays key roles in vertebrate tissue boundary formation, axonal pathfinding, and stem cell regeneration by steering cells to positions defined by its ligand ephrin. Some of the key events in Eph-ephrin signaling are understood: ephrin binding triggers the clustering of the Eph receptor, fostering transphosphorylation and signal transduction into the cell. However, a quantitative and mechanistic understanding of how the signal is processed by the recipient cell into precise and proportional responses is largely lacking. Studying Eph activation kinetics requires spatiotemporal data on the number and distribution of receptor oligomers, which is beyond the quantitative power offered by prevalent imaging methods. Here we describe an enhanced fluorescence fluctuation imaging analysis, which employs statistical resampling to measure the Eph receptor aggregation distribution within each pixel of an image. By performing this analysis over time courses extending tens of minutes, the information-rich 4D space (x, y, oligomerization, time) results were coupled to straightforward biophysical models of protein aggregation. This analysis reveals that Eph clustering can be explained by the combined contribution of polymerization of receptors into clusters, followed by their condensation into far larger aggregates. The modeling reveals that these two competing oligomerization mechanisms play distinct roles: polymerization mediates the activation of the receptor by assembling monomers into 6- to 8-mer oligomers; condensation of the preassembled oligomers into large clusters containing hundreds of monomers dampens the signaling. We propose that the polymerization-condensation dynamics creates mechanistic explanation for how cells properly respond to variable ligand concentrations and gradients.
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85
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Zeng L, Zhang L, Wang P, Meng G. Structural basis of host recognition and biofilm formation by Salmonella Saf pili. eLife 2017; 6:28619. [PMID: 29125121 PMCID: PMC5700814 DOI: 10.7554/elife.28619] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2017] [Accepted: 11/08/2017] [Indexed: 12/21/2022] Open
Abstract
Pili are critical in host recognition, colonization and biofilm formation during bacterial infection. Here, we report the crystal structures of SafD-dsc and SafD-SafA-SafA (SafDAA-dsc) in Saf pili. Cell adherence assays show that SafD and SafA are both required for host recognition, suggesting a poly-adhesive mechanism for Saf pili. Moreover, the SafDAA-dsc structure, as well as SAXS characterization, reveals an unexpected inter-molecular oligomerization, prompting the investigation of Saf-driven self-association in biofilm formation. The bead/cell aggregation and biofilm formation assays are used to demonstrate the novel function of Saf pili. Structure-based mutants targeting the inter-molecular hydrogen bonds and complementary architecture/surfaces in SafDAA-dsc dimers significantly impaired the Saf self-association activity and biofilm formation. In summary, our results identify two novel functions of Saf pili: the poly-adhesive and self-associating activities. More importantly, Saf-Saf structures and functional characterizations help to define a pili-mediated inter-cellular oligomerizaiton mechanism for bacterial aggregation, colonization and ultimate biofilm formation.
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Affiliation(s)
- Longhui Zeng
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Rui-Jin Hospital, Shanghai JiaoTong University School of Medicine and School of Life Sciences and Biotechnology, Shanghai JiaoTong University, Shanghai, China
| | - Li Zhang
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Rui-Jin Hospital, Shanghai JiaoTong University School of Medicine and School of Life Sciences and Biotechnology, Shanghai JiaoTong University, Shanghai, China
| | - Pengran Wang
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Rui-Jin Hospital, Shanghai JiaoTong University School of Medicine and School of Life Sciences and Biotechnology, Shanghai JiaoTong University, Shanghai, China
| | - Guoyu Meng
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Rui-Jin Hospital, Shanghai JiaoTong University School of Medicine and School of Life Sciences and Biotechnology, Shanghai JiaoTong University, Shanghai, China
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86
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Won SY, Kim CY, Kim D, Ko J, Um JW, Lee SB, Buck M, Kim E, Heo WD, Lee JO, Kim HM. LAR-RPTP Clustering Is Modulated by Competitive Binding between Synaptic Adhesion Partners and Heparan Sulfate. Front Mol Neurosci 2017; 10:327. [PMID: 29081732 PMCID: PMC5645493 DOI: 10.3389/fnmol.2017.00327] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2017] [Accepted: 09/28/2017] [Indexed: 01/07/2023] Open
Abstract
The leukocyte common antigen-related receptor protein tyrosine phosphatases (LAR-RPTPs) are cellular receptors of heparan sulfate (HS) and chondroitin sulfate (CS) proteoglycans that direct axonal growth and neuronal regeneration. LAR-RPTPs are also synaptic adhesion molecules that form trans-synaptic adhesion complexes by binding to various postsynaptic adhesion ligands, such as Slit- and Trk-like family of proteins (Slitrks), IL-1 receptor accessory protein-like 1 (IL1RAPL1), interleukin-1 receptor accessory protein (IL-1RAcP) and neurotrophin receptor tyrosine kinase C (TrkC), to regulate synaptogenesis. Here, we determined the crystal structure of the human LAR-RPTP/IL1RAPL1 complex and found that lateral interactions between neighboring LAR-RPTP/IL1RAPL1 complexes in crystal lattices are critical for the higher-order assembly and synaptogenic activity of these complexes. Moreover, we found that LAR-RPTP binding to the postsynaptic adhesion ligands, Slitrk3, IL1RAPL1 and IL-1RAcP, but not TrkC, induces reciprocal higher-order clustering of trans-synaptic adhesion complexes. Although LAR-RPTP clustering was induced by either HS or postsynaptic adhesion ligands, the dominant binding of HS to the LAR-RPTP was capable of dismantling pre-established LAR-RPTP-mediated trans-synaptic adhesion complexes. These findings collectively suggest that LAR-RPTP clustering for synaptogenesis is modulated by a complex synapse-organizing protein network.
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Affiliation(s)
- Seoung Youn Won
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea
| | - Cha Yeon Kim
- Graduate School of Nanoscience and Technology, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea
| | - Doyoun Kim
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, South Korea
| | - Jaewon Ko
- Department of Brain & Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, South Korea
| | - Ji Won Um
- Department of Brain & Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, South Korea
| | - Sung Bae Lee
- Department of Brain & Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, South Korea
| | - Matthias Buck
- Department of Physiology and Biophysics, Case Western Reserve University, School of Medicine, Cleveland, OH, United States
| | - Eunjoon Kim
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, South Korea,Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea
| | - Won Do Heo
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea,Center for Cognition and Sociality, Institute for Basic Science (IBS), Daejeon, South Korea,*Correspondence: Ho Min Kim Jie-Oh Lee Won Do Heo
| | - Jie-Oh Lee
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea,*Correspondence: Ho Min Kim Jie-Oh Lee Won Do Heo
| | - Ho Min Kim
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, South Korea,Graduate School of Medical Science & Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea,*Correspondence: Ho Min Kim Jie-Oh Lee Won Do Heo
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87
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Petty A, Idippily N, Bobba V, Geldenhuys WJ, Zhong B, Su B, Wang B. Design and synthesis of small molecule agonists of EphA2 receptor. Eur J Med Chem 2017; 143:1261-1276. [PMID: 29128116 DOI: 10.1016/j.ejmech.2017.10.026] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 10/09/2017] [Accepted: 10/09/2017] [Indexed: 12/30/2022]
Abstract
Ligand-independent activation of EphA2 receptor kinase promotes cancer metastasis and invasion. Activating EphA2 receptor tyrosine kinase with small molecule agonist is a novel strategy to treat EphA2 overexpressing cancer. In this study, we performed a lead optimization of a small molecule Doxazosin that was identified as an EphA2 receptor agonist. 33 new analogs were developed and evaluated; a structure-activity relationship was summarized based on the EphA2 activation of these derivatives. Two new derivative compounds 24 and 27 showed much improved activity compared to Doxazosin. Compound 24 possesses a bulky amide moiety, and compound 27 has a dimeric structure that is very different to the parental compound. Compound 27 with a twelve-carbon linker of the dimer activated the kinase and induced receptor internalization and cell death with the best potency. Another dimer with a six-carbon linker has significantly reduced potency compared to the dimer with a longer linker, suggesting that the length of the linker is critical for the activity of the dimeric agonist. To explore the receptor binding characteristics of the new molecules, we applied a docking study to examine how the small molecule binds to the EphA2 receptor. The results reveal that compounds 24 and 27 form more hydrogen bonds to EphA2 than Doxazosin, suggesting that they may have higher binding affinity to the receptor.
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Affiliation(s)
- Aaron Petty
- Rammelkamp Center for Research and Department of Medicine, MetroHealth Campus, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Nethrie Idippily
- Department of Chemistry, Center for Gene Regulation in Health and Disease, College of Sciences & Health Professions, Cleveland State University, 2121 Euclid Ave., Cleveland, OH, 44115, USA
| | - Viharika Bobba
- Department of Chemistry, Center for Gene Regulation in Health and Disease, College of Sciences & Health Professions, Cleveland State University, 2121 Euclid Ave., Cleveland, OH, 44115, USA
| | - Werner J Geldenhuys
- Department of Pharmaceutical Sciences, School of Pharmacy, Robert C. Byrd Health Sciences Center, West Virginia University, USA
| | - Bo Zhong
- Department of Chemistry, Center for Gene Regulation in Health and Disease, College of Sciences & Health Professions, Cleveland State University, 2121 Euclid Ave., Cleveland, OH, 44115, USA
| | - Bin Su
- Department of Chemistry, Center for Gene Regulation in Health and Disease, College of Sciences & Health Professions, Cleveland State University, 2121 Euclid Ave., Cleveland, OH, 44115, USA.
| | - Bingcheng Wang
- Rammelkamp Center for Research and Department of Medicine, MetroHealth Campus, Case Western Reserve University School of Medicine, Cleveland, OH, USA; Case Comprehensive Cancer Center, Case Western Reserve University School of Medicine, Cleveland, OH, USA.
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88
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Chen Y, Zhang H, Zhang Y. Targeting receptor tyrosine kinase EphB4 in cancer therapy. Semin Cancer Biol 2017; 56:37-46. [PMID: 28993206 DOI: 10.1016/j.semcancer.2017.10.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 09/13/2017] [Accepted: 10/04/2017] [Indexed: 12/12/2022]
Abstract
Eph receptors and their Eph receptor-interacting (ephrin) ligands together form an important cell communication system with diverse roles. Experimental evidence demonstrated Eph receptor bidirectional signaling with both tumor-suppressing and tumor-promoting activities in cancer cells. The tyrosine kinase EphB4, a member of the Eph receptor family, has been associated with tumor angiogenesis, growth and metastasis, thus making it a valuable and attractive target for drug design for therapeutic applications. In the past decade, many studies have focused on elucidating the structure and function of EphB4 in complex with its ligand ephrinB2 for their role in carcinogenesis. Meanwhile, an array of compounds targeting EphB4 have been studied and several selective inhibitors have been tested in clinical studies. This review discusses the structure and function of the EphB4 receptor, analyzes its potential as a target for anticancer therapy, and summarizes the information about inhibitors of EphB4 kinase activity. Conclusively, EphB4 is a challenging but promising therapeutic target in cancer.
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Affiliation(s)
- Yinnan Chen
- School of Molecular Sciences, Arizona State University, Tempe, AZ 85287, USA
| | - Hongmei Zhang
- Department of Endocrinology, Xinhua Hospital affiliated to Shanghai Jiaotong University School of Medicine, 1665 Kongjiang Road, Shanghai 200092, PR China.
| | - Yanmin Zhang
- School of Pharmacy, Health Science Center, Xi'an Jiaotong University, No. 76, Yanta West Street, #54, Xi'an, Shaanxi Province 710061, PR China.
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89
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Bocharov EV. Alternative dimerization of receptor tyrosine kinases with signal transduction through a cellular membrane. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2017. [DOI: 10.1134/s1068162017050041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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90
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Conformational transitions and interactions underlying the function of membrane embedded receptor protein kinases. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:1417-1429. [DOI: 10.1016/j.bbamem.2017.01.025] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 01/06/2017] [Accepted: 01/09/2017] [Indexed: 01/08/2023]
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91
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Tosato G. Ephrin ligands and Eph receptors contribution to hematopoiesis. Cell Mol Life Sci 2017; 74:3377-3394. [PMID: 28589441 PMCID: PMC11107787 DOI: 10.1007/s00018-017-2566-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 05/12/2017] [Accepted: 06/01/2017] [Indexed: 12/12/2022]
Abstract
Hematopoietic stem and progenitor cells reside predominantly in the bone marrow. They supply billions of mature blood cells every day during life through maturation into multilineage progenitors and self-renewal. Newly produced mature cells serve to replenish the pool of circulating blood cells at the end of their life-span. These mature blood cells and a few hematopoietic progenitors normally exit the bone marrow through the sinusoidal vessels, a specialized venous vascular system that spreads throughout the bone marrow. Many signals regulate the coordinated mobilization of hematopoietic cells from the bone marrow to the circulation. In this review, we present recent advances on hematopoiesis and hematopoietic cell mobilization with a focus on the role of Ephrin ligands and their Eph receptors. These constitute a large family of transmembrane ligands and receptors that play critical roles in development and postnatally. New insights point to distinct roles of ephrin and Eph in different aspects of hematopoiesis.
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Affiliation(s)
- Giovanna Tosato
- Laboratory of Cellular Oncology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Building 37, Room 4124, Bethesda, MD, 20892, USA.
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92
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Hanamura K, Washburn HR, Sheffler-Collins SI, Xia NL, Henderson N, Tillu DV, Hassler S, Spellman DS, Zhang G, Neubert TA, Price TJ, Dalva MB. Extracellular phosphorylation of a receptor tyrosine kinase controls synaptic localization of NMDA receptors and regulates pathological pain. PLoS Biol 2017; 15:e2002457. [PMID: 28719605 PMCID: PMC5515392 DOI: 10.1371/journal.pbio.2002457] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 06/12/2017] [Indexed: 11/18/2022] Open
Abstract
Extracellular phosphorylation of proteins was suggested in the late 1800s when it was demonstrated that casein contains phosphate. More recently, extracellular kinases that phosphorylate extracellular serine, threonine, and tyrosine residues of numerous proteins have been identified. However, the functional significance of extracellular phosphorylation of specific residues in the nervous system is poorly understood. Here we show that synaptic accumulation of GluN2B-containing N-methyl-D-aspartate receptors (NMDARs) and pathological pain are controlled by ephrin-B-induced extracellular phosphorylation of a single tyrosine (p*Y504) in a highly conserved region of the fibronectin type III (FN3) domain of the receptor tyrosine kinase EphB2. Ligand-dependent Y504 phosphorylation modulates the EphB-NMDAR interaction in cortical and spinal cord neurons. Furthermore, Y504 phosphorylation enhances NMDAR localization and injury-induced pain behavior. By mediating inducible extracellular interactions that are capable of modulating animal behavior, extracellular tyrosine phosphorylation of EphBs may represent a previously unknown class of mechanism mediating protein interaction and function. The activity of proteins can be finely and reversibly tuned by post-translational modifications. The attachment of phosphate groups to tyrosine residues is one of such modifications. While the existence of extracellular phosphoproteins has been known, the functional significance of extracellular phosphorylation is poorly understood. Here we describe a single extracellular tyrosine whose inducible phosphorylation may represent an archetype for a new class of mechanism mediating protein—protein interaction and regulating protein function. We show that the interaction between EphB2—which occurs upon receptor activation by its ligand ephrin-B—and the N-methyl-D-aspartate receptor (NMDAR) depends on extracellular phosphorylation of EphB2. This interaction regulates the localization of the NMDA receptor to synaptic sites in neurons. In vivo, EphB2 is phosphorylated in response to injury, and the subsequent up-regulation of the interaction between EphB2 and NMDA receptors enhances injury-induced pain behavior and mechanical hypersensitivity in mice. Importantly, our study defines a specific extracellular phosphorylation event as a mechanism driving protein interaction and suggests that extracellular phosphorylation of proteins is an underappreciated mechanism contributing to the development and function of the nervous system and synapse.
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Affiliation(s)
- Kenji Hanamura
- Department of Neuroscience and Farber Institute for Neurosciences, Thomas Jefferson University, Jefferson Hospital for Neuroscience, Philadelphia, Pennsylvania, United States of America
- Department of Neurobiology and Behavior, Gunma University Graduate School of Medicine, Maebashi City, Gunma, Japan
| | - Halley R. Washburn
- Department of Neuroscience and Farber Institute for Neurosciences, Thomas Jefferson University, Jefferson Hospital for Neuroscience, Philadelphia, Pennsylvania, United States of America
| | - Sean I. Sheffler-Collins
- Department of Neuroscience and Farber Institute for Neurosciences, Thomas Jefferson University, Jefferson Hospital for Neuroscience, Philadelphia, Pennsylvania, United States of America
- Neuroscience Graduate Group, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Nan L. Xia
- Department of Neuroscience and Farber Institute for Neurosciences, Thomas Jefferson University, Jefferson Hospital for Neuroscience, Philadelphia, Pennsylvania, United States of America
| | - Nathan Henderson
- Department of Neuroscience and Farber Institute for Neurosciences, Thomas Jefferson University, Jefferson Hospital for Neuroscience, Philadelphia, Pennsylvania, United States of America
| | - Dipti V. Tillu
- Department of Pharmacology, University of Arizona College of Medicine, Tucson, Arizona, United States of America
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, Texas, United States of America
| | - Shayne Hassler
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, Texas, United States of America
| | - Daniel S. Spellman
- Department of Cell Biology and Kimmel Center for Biology and Medicine at the Skirball Institute, New York University School of Medicine, New York, New York, United States of America
| | - Guoan Zhang
- Department of Cell Biology and Kimmel Center for Biology and Medicine at the Skirball Institute, New York University School of Medicine, New York, New York, United States of America
| | - Thomas A. Neubert
- Department of Cell Biology and Kimmel Center for Biology and Medicine at the Skirball Institute, New York University School of Medicine, New York, New York, United States of America
| | - Theodore J. Price
- Department of Pharmacology, University of Arizona College of Medicine, Tucson, Arizona, United States of America
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, Texas, United States of America
| | - Matthew B. Dalva
- Department of Neuroscience and Farber Institute for Neurosciences, Thomas Jefferson University, Jefferson Hospital for Neuroscience, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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93
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Kim MA, Yoon HS, Park SH, Kim DY, Pyo A, Kim HS, Min JJ, Hong Y. Engineering of monobody conjugates for human EphA2-specific optical imaging. PLoS One 2017; 12:e0180786. [PMID: 28686661 PMCID: PMC5501600 DOI: 10.1371/journal.pone.0180786] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2017] [Accepted: 06/21/2017] [Indexed: 02/06/2023] Open
Abstract
In a previous study, we developed an E1 monobody specific for the tumor biomarker hEphA2 [PLoS ONE (2015) 10(7): e0132976]. E1 showed potential as a molecular probe for in vitro and in vivo targeting of cancers overexpressing hEphA2. In the present study, we constructed expression vectors for E1 conjugated to optical reporters such as Renilla luciferase variant 8 (Rluc8) or enhanced green fluorescent protein (EGFP) and purified such recombinant proteins by affinity chromatography in E. coli. E1-Rluc8 and E1-EGFP specifically bound to hEphA2 in human prostate cancer PC3 cells but not in human cervical cancer HeLa cells, which express hEphA2 at high and low levels, respectively. These recombinant proteins maintained >40% activity in mouse serum at 24 h. In vivo optical imaging for 24 h did not detect E1-EGFP signals, whereas E1-Rluc8 showed tumor-specific luminescence signals in PC3 but not in HeLa xenograft mice. E1-Rluc8 signals were detected at 4 h, peaked at 12 h, and were undetectable at 24 h. These results suggest the potential of E1-Rluc8 as an EphA2-specific optical imaging agent.
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MESH Headings
- Animals
- Antibodies, Neoplasm/biosynthesis
- Antibodies, Neoplasm/chemistry
- Biomarkers, Tumor/analysis
- Biomarkers, Tumor/genetics
- Biomarkers, Tumor/metabolism
- Cell Line, Tumor
- Escherichia coli/genetics
- Escherichia coli/metabolism
- Female
- Genes, Reporter
- Genetic Vectors/chemistry
- Genetic Vectors/metabolism
- Green Fluorescent Proteins/genetics
- Green Fluorescent Proteins/metabolism
- HeLa Cells
- Heterografts
- Humans
- Immunoconjugates/chemistry
- Immunoconjugates/metabolism
- Luciferases/genetics
- Luciferases/metabolism
- Male
- Mice, Inbred BALB C
- Mice, Nude
- Optical Imaging
- Organ Specificity
- Protein Engineering
- Receptor, EphA2/analysis
- Receptor, EphA2/genetics
- Receptor, EphA2/metabolism
- Recombinant Fusion Proteins/genetics
- Recombinant Fusion Proteins/metabolism
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Affiliation(s)
- Min-A Kim
- Department of Microbiology, Chonnam National University Medical School, Gwangju, Republic of Korea
- Department of Molecular Medicine (BK21Plus), Chonnam National University Medical School, Gwangju, Republic of Korea
| | - Hee Seung Yoon
- Department of Molecular Medicine (BK21Plus), Chonnam National University Medical School, Gwangju, Republic of Korea
- Department of Nuclear Medicine, Chonnam National University Medical School, Gwangju, Republic of Korea
| | - Seung-Hwan Park
- Biological Resource Center, Korea Research Institute of Bioscience & Biotechnology (KRIBB), Jeongeup, Republic of Korea
| | - Dong-Yeon Kim
- Department of Nuclear Medicine, Chonnam National University Medical School, Gwangju, Republic of Korea
| | - Ayoung Pyo
- Department of Nuclear Medicine, Chonnam National University Medical School, Gwangju, Republic of Korea
| | - Hyeon Sik Kim
- Department of Nuclear Medicine, Chonnam National University Medical School, Gwangju, Republic of Korea
| | - Jung-Joon Min
- Department of Nuclear Medicine, Chonnam National University Medical School, Gwangju, Republic of Korea
| | - Yeongjin Hong
- Department of Microbiology, Chonnam National University Medical School, Gwangju, Republic of Korea
- * E-mail:
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94
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Abstract
Eph-ephrin bidirectional signaling is essential for eye lens transparency in humans and mice. Our previous studies in mouse lenses demonstrate that ephrin-A5 is mainly expressed in the anterior epithelium, where it is required for maintaining the anterior epithelial monolayer. In contrast, EphA2 is localized in equatorial epithelial and fiber cells where it is essential for equatorial epithelial and fiber cell organization and hexagonal cell shape. Immunostaining of lens epithelial and fiber cells reveals that EphA2 and ephrin-A5 are also co-expressed in anterior fiber cell tips, equatorial epithelial cells and newly formed lens fibers, although they are not precisely colocalized. Due to this complex expression pattern and the promiscuous interactions between Eph receptors and ephrin ligands, as well as their complex bidirectional signaling pathways, cataracts in ephrin-A5(-/-) or EphA2(-/-) lenses may arise from loss of function or abnormal signaling mechanisms. To test whether abnormal signaling mechanisms may play a role in cataractogenesis in ephrin-A5(-/-) or EphA2(-/-) lenses, we generated EphA2 and ephrin-A5 double knockout (DKO) mice. We compared the phenotypes of EphA2(-/-) and ephrin-A5(-/-) lenses to that of DKO lenses. DKO lenses displayed an additive lens phenotype that was not significantly different from the two single KO lens phenotypes. Similar to ephrin-A5(-/-) lenses, DKO lenses had abnormal anterior epithelial cells leading to a large mass of epithelial cells that invade into the underlying fiber cell layer, directly resulting in anterior cataracts in ephrin-A5(-/-) and DKO lenses. Yet, similar to EphA2(-/-) lenses, DKO lenses also had abnormal packing of equatorial epithelial cells with disorganized meridional rows, lack of a lens fulcrum and disrupted fiber cells. The DKO lens phenotype rules out abnormal signaling by EphA2 in ephrin-A5(-/-) lenses or by ephrin-A5 in EphA2(-/-) lenses as possible cataract mechanisms. Thus, these results indicate that EphA2 and ephrin-A5 do not form a lens receptor-ligand pair, and that EphA2 and ephrin-A5 have other binding partners in the lens to help align differentiating equatorial epithelial cells or maintain the anterior epithelium, respectively.
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95
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Juskaite V, Corcoran DS, Leitinger B. Collagen induces activation of DDR1 through lateral dimer association and phosphorylation between dimers. eLife 2017; 6. [PMID: 28590245 PMCID: PMC5489314 DOI: 10.7554/elife.25716] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 06/07/2017] [Indexed: 01/04/2023] Open
Abstract
The collagen-binding receptor tyrosine kinase DDR1 (discoidin domain receptor 1) is a drug target for a wide range of human diseases, but the molecular mechanism of DDR1 activation is poorly defined. Here we co-expressed different types of signalling-incompetent DDR1 mutants (‘receiver’) with functional DDR1 (‘donor’) and demonstrate phosphorylation of receiver DDR1 by donor DDR1 in response to collagen. Making use of enforced covalent DDR1 dimerisation, which does not affect receptor function, we show that receiver dimers are phosphorylated in trans by the donor; this process requires the kinase activity of the donor but not that of the receiver. The receiver ectodomain is not required, but phosphorylation in trans is abolished by mutation of the transmembrane domain. Finally, we show that mutant DDR1 that cannot bind collagen is recruited into DDR1 signalling clusters. Our results support an activation mechanism whereby collagen induces lateral association of DDR1 dimers and phosphorylation between dimers. DOI:http://dx.doi.org/10.7554/eLife.25716.001 The membrane surrounding each living cell contains a variety of proteins that carry out different roles. For example, proteins called receptor tyrosine kinases help a cell to receive signals from its external environment. Receptor tyrosine kinases span the membrane so that one part of the protein known as the ectodomain sticks out from the surface of the cell, while another part (called the kinase domain) sits inside the cell. When a signalling molecule binds to the ectodomain, the kinase domain becomes active and starts to add chemical groups called phosphates to other proteins. This process, known as phosphorylation, changes the protein’s activity, which in turn influences the cell’s behaviour. In most cases, the signalling molecule causes two receptor tyrosine kinase proteins to bind to each other and form a “dimer” in which the kinase domains are able to phosphorylate, and thus activate, each other. Female mammals need a receptor tyrosine kinase called DDR1 to develop mammary glands (the glands that produce milk). DDR1 is activated when a signalling molecule called collagen binds to its ectodomain. Unlike many other receptor tyrosine kinases, DDR1 exists as a dimer even before it binds to collagen, so it is not clear how collagen activates DDR1. One possibility is that collagen causes several DDR1 dimers to form clusters on the membrane so that kinases on neighbouring dimers can phosphorylate each other. Juskaite et al. explored this idea by pairing up normal DDR1 proteins with mutant versions that are unable to bind to collagen. The experiments show that when collagen binds to the normal DDR1 molecules, DDR1 dimers do indeed form clusters. This enables the normal protein molecules in neighbouring dimers to phosphorylate each other as well as the mutant proteins. In this way, the clustered DDR1 dimers can become active even if the clusters contain one or more mutant versions that are unable to detect collagen. Further experiments show that specific contacts need to form between neighbouring dimers for this phosphorylation to occur. Abnormal DDR1 activity is associated with several diseases including cancer, inflammation and fibrosis. The findings of Juskaite et al. suggest that developing new drugs that can prevent DDR1 from forming clusters may help to treat people with these conditions. Further work is also needed to analyse the size and structure of DDR1 clusters and investigate if other proteins also associate with the clusters. DOI:http://dx.doi.org/10.7554/eLife.25716.002
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Affiliation(s)
- Victoria Juskaite
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - David S Corcoran
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Birgit Leitinger
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
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96
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A role of the SAM domain in EphA2 receptor activation. Sci Rep 2017; 7:45084. [PMID: 28338017 PMCID: PMC5364462 DOI: 10.1038/srep45084] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 02/17/2017] [Indexed: 11/08/2022] Open
Abstract
Among the 20 subfamilies of protein receptor tyrosine kinases (RTKs), Eph receptors are unique in possessing a sterile alpha motif (SAM domain) at their C-terminal ends. However, the functions of SAM domains in Eph receptors remain elusive. Here we report on a combined cell biology and quantitative fluorescence study to investigate the role of the SAM domain in EphA2 function. We observed elevated tyrosine autophosphorylation levels upon deletion of the EphA2 SAM domain (EphA2ΔS) in DU145 and PC3 prostate cancer cells and a skin tumor cell line derived from EphA1/A2 knockout mice. These results suggest that SAM domain deletion induced constitutive activation of EphA2 kinase activity. In order to explain these effects, we applied fluorescence correlation spectroscopy to investigate the lateral molecular organization of EphA2. Our results indicate that SAM domain deletion (EphA2ΔS-GFP) increases oligomerization compared to the full length receptor (EphA2FL-GFP). Stimulation with ephrinA1, a ligand for EphA2, induced further oligomerization and activation of EphA2FL-GFP. The SAM domain deletion mutant, EphA2ΔS-GFP, also underwent further oligomerization upon ephrinA1 stimulation, but the oligomers were larger than those observed for EphA2FL-GFP. Based on these results, we conclude that the EphA2 SAM domain inhibits kinase activity by reducing receptor oligomerization.
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97
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Peng H, Park JK, Lavker RM. Autophagy and Macropinocytosis: Keeping an Eye on the Corneal/Limbal Epithelia. Invest Ophthalmol Vis Sci 2017; 58:416-423. [PMID: 28118670 PMCID: PMC5270618 DOI: 10.1167/iovs.16-21111] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 12/05/2016] [Indexed: 02/07/2023] Open
Abstract
Autophagy and macropinocytosis are processes that are vital for cellular homeostasis, and help cells respond to stress and take up large amounts of material, respectively. The limbal and corneal epithelia have the machinery necessary to carry out both processes; however, autophagy and macropinocytosis are relatively understudied in these two epithelia. In this Perspectives, we describe the basic principles behind macropinocytosis and autophagy, discuss how these two processes are regulated in the limbal and corneal epithelia, consider how these two processes impact on the physiology of limbal and corneal epithelia, and elaborate on areas of future research in autophagy and macropinocytosis as related to the limbal/corneal epithelia.
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Affiliation(s)
- Han Peng
- Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States
| | - Jong Kook Park
- Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States
| | - Robert M. Lavker
- Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States
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98
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Dong X, Yu Y, Wang Q, Xi Y, Liu Y. Interaction Mechanism and Clustering among RGD Peptides and Integrins. Mol Inform 2016; 36. [DOI: 10.1002/minf.201600069] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 11/27/2016] [Indexed: 02/05/2023]
Affiliation(s)
- Xiuli Dong
- Soft Matter Research Center; Department of Chemistry; Zhejiang University; Hangzhou 310027 PR China
- College of Pharmacy; Binzhou Medical University; Yantai 264003 PR China
| | - Yuping Yu
- Soft Matter Research Center; Department of Chemistry; Zhejiang University; Hangzhou 310027 PR China
| | - Qi Wang
- Soft Matter Research Center; Department of Chemistry; Zhejiang University; Hangzhou 310027 PR China
| | - Ying Xi
- Department of Pharmaceutics; Peking University; Beijing 100191 PR China
| | - Yingchun Liu
- Soft Matter Research Center; Department of Chemistry; Zhejiang University; Hangzhou 310027 PR China
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99
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Sullivan CS, Kümper M, Temple BS, Maness PF. The Neural Cell Adhesion Molecule (NCAM) Promotes Clustering and Activation of EphA3 Receptors in GABAergic Interneurons to Induce Ras Homolog Gene Family, Member A (RhoA)/Rho-associated protein kinase (ROCK)-mediated Growth Cone Collapse. J Biol Chem 2016; 291:26262-26272. [PMID: 27803162 DOI: 10.1074/jbc.m116.760017] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 10/24/2016] [Indexed: 02/03/2023] Open
Abstract
Establishment of a proper balance of excitatory and inhibitory connectivity is achieved during development of cortical networks and adjusted through synaptic plasticity. The neural cell adhesion molecule (NCAM) and the receptor tyrosine kinase EphA3 regulate the perisomatic synapse density of inhibitory GABAergic interneurons in the mouse frontal cortex through ephrin-A5-induced growth cone collapse. In this study, it was demonstrated that binding of NCAM and EphA3 occurred between the NCAM Ig2 domain and EphA3 cysteine-rich domain (CRD). The binding interface was further refined through molecular modeling and mutagenesis and shown to be comprised of complementary charged residues in the NCAM Ig2 domain (Arg-156 and Lys-162) and the EphA3 CRD (Glu-248 and Glu-264). Ephrin-A5 induced co-clustering of surface-bound NCAM and EphA3 in GABAergic cortical interneurons in culture. Receptor clustering was impaired by a charge reversal mutation that disrupted NCAM/EphA3 association, emphasizing the importance of the NCAM/EphA3 binding interface for cluster formation. NCAM enhanced ephrin-A5-induced EphA3 autophosphorylation and activation of RhoA GTPase, indicating a role for NCAM in activating EphA3 signaling through clustering. NCAM-mediated clustering of EphA3 was essential for ephrin-A5-induced growth cone collapse in cortical GABAergic interneurons, and RhoA and a principal effector, Rho-associated protein kinase, mediated the collapse response. This study delineates a mechanism in which NCAM promotes ephrin-A5-dependent clustering of EphA3 through interaction of the NCAM Ig2 domain and the EphA3 CRD, stimulating EphA3 autophosphorylation and RhoA signaling necessary for growth cone repulsion in GABAergic interneurons in vitro, which may extend to remodeling of axonal terminals of interneurons in vivo.
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Affiliation(s)
- Chelsea S Sullivan
- From the Department of Biochemistry and Biophysics, R. L. Juliano Structural Bioinformatics Core, School of Medicine, University of North Carolina, Chapel Hill, North Carolina 27599-7264
| | - Maike Kümper
- From the Department of Biochemistry and Biophysics, R. L. Juliano Structural Bioinformatics Core, School of Medicine, University of North Carolina, Chapel Hill, North Carolina 27599-7264
| | - Brenda S Temple
- From the Department of Biochemistry and Biophysics, R. L. Juliano Structural Bioinformatics Core, School of Medicine, University of North Carolina, Chapel Hill, North Carolina 27599-7264
| | - Patricia F Maness
- From the Department of Biochemistry and Biophysics, R. L. Juliano Structural Bioinformatics Core, School of Medicine, University of North Carolina, Chapel Hill, North Carolina 27599-7264
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100
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Singh DR, Ahmed F, Paul MD, Gedam M, Pasquale EB, Hristova K. The SAM domain inhibits EphA2 interactions in the plasma membrane. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1864:31-38. [PMID: 27776928 DOI: 10.1016/j.bbamcr.2016.10.011] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 09/26/2016] [Accepted: 10/18/2016] [Indexed: 11/18/2022]
Abstract
All members of the Eph receptor family of tyrosine kinases contain a SAM domain near the C terminus, which has been proposed to play a role in receptor homotypic interactions and/or interactions with binding partners. The SAM domain of EphA2 is known to be important for receptor function, but its contribution to EphA2 lateral interactions in the plasma membrane has not been determined. Here we use a FRET-based approach to directly measure the effect of the SAM domain on the stability of EphA2 dimers on the cell surface in the absence of ligand binding. We also investigate the functional consequences of EphA2 SAM domain deletion. Surprisingly, we find that the EphA2 SAM domain inhibits receptor dimerization and decreases EphA2 tyrosine phosphorylation. This role is dramatically different from the role of the SAM domain of the related EphA3 receptor, which we previously found to stabilize EphA3 dimers and increase EphA3 tyrosine phosphorylation in cells in the absence of ligand. Thus, the EphA2 SAM domain likely contributes to a unique mode of EphA2 interaction that leads to distinct signaling outputs.
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Affiliation(s)
- Deo R Singh
- Department of Materials Science and Engineering, Johns Hopkins University, 3400 Charles Street, Baltimore, MD 21218, United States
| | - Fozia Ahmed
- Department of Materials Science and Engineering, Johns Hopkins University, 3400 Charles Street, Baltimore, MD 21218, United States
| | - Michael D Paul
- Program in Molecular Biophysics, Johns Hopkins University, 3400 Charles street, Baltimore, MD 21218, United States
| | - Manasee Gedam
- Department of Materials Science and Engineering, Johns Hopkins University, 3400 Charles Street, Baltimore, MD 21218, United States
| | - Elena B Pasquale
- Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Road, La Jolla, San Diego, CA 92037, United States
| | - Kalina Hristova
- Department of Materials Science and Engineering, Johns Hopkins University, 3400 Charles Street, Baltimore, MD 21218, United States; Program in Molecular Biophysics, Johns Hopkins University, 3400 Charles street, Baltimore, MD 21218, United States.
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