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Lay CS, Kilpatrick LE, Craggs PD, Hill SJ. Use of NanoBiT and NanoBRET to characterise interleukin-23 receptor dimer formation in living cells. Br J Pharmacol 2023; 180:1444-1459. [PMID: 36560872 PMCID: PMC10953408 DOI: 10.1111/bph.16018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 12/02/2022] [Accepted: 12/19/2022] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND AND PURPOSE Interleukin-23 (IL-23) and its receptor are important drug targets for the treatment of auto-inflammatory diseases. IL-23 binds to a receptor complex composed of two single transmembrane spanning proteins IL23R and IL12Rβ1. In this study, we aimed to gain further understanding of how ligand binding induces signalling of IL-23 receptor complexes using the proximity-based techniques of NanoLuc Binary Technology (NanoBiT) and Bioluminescence Resonance Energy Transfer (BRET). EXPERIMENTAL APPROACH To monitor the formation of IL-23 receptor complexes, we developed a split luciferase (NanoBiT) assay whereby heteromerisation of receptor subunits can be measured through luminescence. The affinity of NanoBiT complemented complexes for IL-23 was measured using NanoBRET, and cytokine-induced signal transduction was measured using a phospho-STAT3 AlphaLISA assay. KEY RESULTS NanoBiT measurements demonstrated that IL-23 receptor complexes formed to an equal degree in the presence and absence of ligand. NanoBRET measurements confirmed that these complexes bound IL-23 with a picomolar binding affinity. Measurement of STAT3 phosphorylation demonstrated that pre-formed IL-23 receptor complexes induced signalling following ligand binding. It was also demonstrated that synthetic ligand-independent signalling could be induced by high affinity (HiBit) but not low affinity (SmBit) NanoBiT crosslinking of the receptor N-terminal domains. CONCLUSIONS AND IMPLICATIONS These results indicate that receptor complexes form prior to ligand binding and are not sufficient to induce signalling alone. Our findings indicate that IL-23 induces a conformational change in heteromeric receptor complexes, to enable signal transduction. These observations have direct implications for drug discovery efforts to target the IL-23 receptor.
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Affiliation(s)
- Charles S. Lay
- Division of Physiology, Pharmacology and Neuroscience, School of Life SciencesUniversity of NottinghamNottinghamUK
- Centre of Membrane Proteins and ReceptorsUniversity of Birmingham and NottinghamThe MidlandsUK
- Medicine Design, Medicinal Science and TechnologyGlaxoSmithKlineStevenageUK
| | - Laura E. Kilpatrick
- Centre of Membrane Proteins and ReceptorsUniversity of Birmingham and NottinghamThe MidlandsUK
- Division of Bimolecular Science and Medicinal Chemistry, School of Pharmacy, Biodiscovery InstituteUniversity of NottinghamNottinghamUK
| | - Peter D. Craggs
- Medicine Design, Medicinal Science and TechnologyGlaxoSmithKlineStevenageUK
- Crick‐GSK Biomedical LinklabsGlaxoSmithKlineStevenageUK
| | - Stephen J. Hill
- Division of Physiology, Pharmacology and Neuroscience, School of Life SciencesUniversity of NottinghamNottinghamUK
- Centre of Membrane Proteins and ReceptorsUniversity of Birmingham and NottinghamThe MidlandsUK
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Pandita P, Bhalla R, Saini A, Mani I. Emerging tools for studying receptor endocytosis and signaling. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2023; 194:19-48. [PMID: 36631193 DOI: 10.1016/bs.pmbts.2022.10.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Ligands, agonists, or antagonists use receptor-mediated endocytosis (RME) to reach their intracellular targets. After the internalization of ligand-receptor complexes, it traffics through different subcellular organelles such as early endosome, recycling endosome, lysosome, etc. Further, after the ligand binding to the receptor, different second messengers are generated, such as cGMP, cAMP, IP3, etc. Several methods have been used, such as radioligand binding assay, western blotting, co-immunoprecipitation (co-IP), qRT-PCR, immunofluorescence and confocal microscopy, microRNA/siRNA, and bioassays to understand the various events, such as internalization, subcellular trafficking, signaling, metabolic degradation, etc. This chapter briefly discusses the key principles and methods used to study internalization, subcellular trafficking, signaling, and metabolic degradation of numerous receptors.
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Affiliation(s)
- Pratiksha Pandita
- Faculty of Medicine, Department of Infectious Disease, Imperial College London, London, United Kingdom
| | - Rhea Bhalla
- ICMR-National Institute of Virology, Pune, Maharashtra, India
| | - Ashok Saini
- Department of Microbiology, Institute of Home Economics, University of Delhi, New Delhi, India
| | - Indra Mani
- Department of Microbiology, Gargi College, University of Delhi, New Delhi, India.
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Chiloiro S, Bianchi A, Giampietro A, Pontecorvi A, Raverot G, Marinis LD. Second line treatment of acromegaly: Pasireotide or Pegvisomant? Best Pract Res Clin Endocrinol Metab 2022; 36:101684. [PMID: 35931640 DOI: 10.1016/j.beem.2022.101684] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Acromegaly is a chronic disease with an increased mortality in case of persistently active disease. The treatment of acromegaly is mainly based on the surgical resection of the GH secreting pituitary tumor and, in cases with persistent disease, on the medical therapy with first generation somatostatin analogues (first gen-SSAs). Data from national registries, meta-analysis and epidemiology studies showed that 24%-65% of acromegaly patients treated with first gen-SSA did not reach the control of disease, requiring second line therapies, as the second gen-SSAs and the GH receptor antagonist. According to the high efficacy of these treatments and their molecular mechanisms of action, the choice of second line therapies should be personalized. In this review, we summarize the evidence on clinical, molecular and morphological aspects that may predict the response to second line therapies, in order to integrate and translate in the clinical practice for a patient-tailored therapeutic approach.
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Affiliation(s)
- Sabrina Chiloiro
- Pituitary Unit, Division of Endocrinology and Metabolism, Fondazione Policlinico Universitario A. Gemelli, IRCCS, Largo A. Gemelli, number 8, Rome, Italy; Dipartimento di Medicina e Chirurgia Traslazionale, Università Cattolica del Sacro Cuore, Rome, Italy.
| | - Antonio Bianchi
- Pituitary Unit, Division of Endocrinology and Metabolism, Fondazione Policlinico Universitario A. Gemelli, IRCCS, Largo A. Gemelli, number 8, Rome, Italy; Dipartimento di Medicina e Chirurgia Traslazionale, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Antonella Giampietro
- Pituitary Unit, Division of Endocrinology and Metabolism, Fondazione Policlinico Universitario A. Gemelli, IRCCS, Largo A. Gemelli, number 8, Rome, Italy; Dipartimento di Medicina e Chirurgia Traslazionale, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Alfredo Pontecorvi
- Pituitary Unit, Division of Endocrinology and Metabolism, Fondazione Policlinico Universitario A. Gemelli, IRCCS, Largo A. Gemelli, number 8, Rome, Italy; Dipartimento di Medicina e Chirurgia Traslazionale, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Gérald Raverot
- Fédération d'endocrinologie, Centre de référence Maladies Rares Hypophysaires (HYPO), Hospices Civils de Lyon, Groupement hospitalier Est, Bron, France; Université Lyon 1, Lyon, France; Inserm U1052, CNRS UMR5286, Cancer Research Center of Lyon, 69372, Lyon, France
| | - Laura De Marinis
- Pituitary Unit, Division of Endocrinology and Metabolism, Fondazione Policlinico Universitario A. Gemelli, IRCCS, Largo A. Gemelli, number 8, Rome, Italy; Dipartimento di Medicina e Chirurgia Traslazionale, Università Cattolica del Sacro Cuore, Rome, Italy
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Downes CEJ, McClure BJ, McDougal DP, Heatley SL, Bruning JB, Thomas D, Yeung DT, White DL. JAK2 Alterations in Acute Lymphoblastic Leukemia: Molecular Insights for Superior Precision Medicine Strategies. Front Cell Dev Biol 2022; 10:942053. [PMID: 35903543 PMCID: PMC9315936 DOI: 10.3389/fcell.2022.942053] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 06/16/2022] [Indexed: 11/13/2022] Open
Abstract
Acute lymphoblastic leukemia (ALL) is the most common pediatric cancer, arising from immature lymphocytes that show uncontrolled proliferation and arrested differentiation. Genomic alterations affecting Janus kinase 2 (JAK2) correlate with some of the poorest outcomes within the Philadelphia-like subtype of ALL. Given the success of kinase inhibitors in the treatment of chronic myeloid leukemia, the discovery of activating JAK2 point mutations and JAK2 fusion genes in ALL, was a breakthrough for potential targeted therapies. However, the molecular mechanisms by which these alterations activate JAK2 and promote downstream signaling is poorly understood. Furthermore, as clinical data regarding the limitations of approved JAK inhibitors in myeloproliferative disorders matures, there is a growing awareness of the need for alternative precision medicine approaches for specific JAK2 lesions. This review focuses on the molecular mechanisms behind ALL-associated JAK2 mutations and JAK2 fusion genes, known and potential causes of JAK-inhibitor resistance, and how JAK2 alterations could be targeted using alternative and novel rationally designed therapies to guide precision medicine approaches for these high-risk subtypes of ALL.
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Affiliation(s)
- Charlotte EJ. Downes
- Blood Cancer Program, Precision Cancer Medicine Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, Australia
- School of Biological Sciences, Faculty of Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Barbara J. McClure
- Blood Cancer Program, Precision Cancer Medicine Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, Australia
- Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Daniel P. McDougal
- School of Biological Sciences, Faculty of Sciences, University of Adelaide, Adelaide, SA, Australia
- Institute for Photonics and Advanced Sensing (IPAS), University of Adelaide, Adelaide, SA, Australia
| | - Susan L. Heatley
- Blood Cancer Program, Precision Cancer Medicine Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, Australia
- Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA, Australia
- Australian and New Zealand Children’s Oncology Group (ANZCHOG), Clayton, VIC, Australia
| | - John B. Bruning
- School of Biological Sciences, Faculty of Sciences, University of Adelaide, Adelaide, SA, Australia
- Institute for Photonics and Advanced Sensing (IPAS), University of Adelaide, Adelaide, SA, Australia
| | - Daniel Thomas
- Blood Cancer Program, Precision Cancer Medicine Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, Australia
- Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA, Australia
| | - David T. Yeung
- Blood Cancer Program, Precision Cancer Medicine Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, Australia
- Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA, Australia
- Department of Haematology, Royal Adelaide Hospital and SA Pathology, Adelaide, SA, Australia
| | - Deborah L. White
- Blood Cancer Program, Precision Cancer Medicine Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, Australia
- School of Biological Sciences, Faculty of Sciences, University of Adelaide, Adelaide, SA, Australia
- Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA, Australia
- Australian and New Zealand Children’s Oncology Group (ANZCHOG), Clayton, VIC, Australia
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5
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Lay CS, Bridges A, Goulding J, Briddon SJ, Soloviev Z, Craggs PD, Hill SJ. Probing the binding of interleukin-23 to individual receptor components and the IL-23 heteromeric receptor complex in living cells using NanoBRET. Cell Chem Biol 2022; 29:19-29.e6. [PMID: 34038748 PMCID: PMC8790524 DOI: 10.1016/j.chembiol.2021.05.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 04/06/2021] [Accepted: 05/04/2021] [Indexed: 02/07/2023]
Abstract
Interleukin-23 (IL-23) is a pro-inflammatory cytokine involved in the host defense against pathogens but is also implicated in the development of several autoimmune disorders. The IL-23 receptor has become a key target for drug discovery, but the exact mechanism of the receptor ligand interaction remains poorly understood. In this study the affinities of IL-23 for its individual receptor components (IL23R and IL12Rβ1) and the heteromeric complex formed between them have been measured in living cells using NanoLuciferase-tagged full-length proteins. Here, we demonstrate that TAMRA-tagged IL-23 has a greater than 7-fold higher affinity for IL12Rβ1 than IL23R. However, in the presence of both receptor subunits, IL-23 affinity is increased more than three orders of magnitude to 27 pM. Furthermore, we show that IL-23 induces a potent change in the position of the N-terminal domains of the two receptor subunits, consistent with a conformational change in the heteromeric receptor structure.
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Affiliation(s)
- Charles S Lay
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK; Centre of Membrane Proteins and Receptors, Universities of Birmingham and Nottingham, The Midlands, UK; Medicine Design, Medicinal Science and Technology, GlaxoSmithKline, Stevenage SG1 2NY, UK
| | - Angela Bridges
- Protein and Cellular Sciences, Medicinal Science and Technology, GlaxoSmithKline, Stevenage SG1 2NY, UK
| | - Joelle Goulding
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK; Centre of Membrane Proteins and Receptors, Universities of Birmingham and Nottingham, The Midlands, UK
| | - Stephen J Briddon
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK; Centre of Membrane Proteins and Receptors, Universities of Birmingham and Nottingham, The Midlands, UK
| | - Zoja Soloviev
- Protein and Cellular Sciences, Medicinal Science and Technology, GlaxoSmithKline, Stevenage SG1 2NY, UK
| | - Peter D Craggs
- Medicine Design, Medicinal Science and Technology, GlaxoSmithKline, Stevenage SG1 2NY, UK; GSK-Francis Crick Institute Linklabs, Medicinal Science and Technology, GlaxoSmithKline, Stevenage SG1 2NY, UK.
| | - Stephen J Hill
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK; Centre of Membrane Proteins and Receptors, Universities of Birmingham and Nottingham, The Midlands, UK.
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Yasmin F, Zeeshan MH, Ullah I. The role of fenofibrate in the treatment of COVID-19. Ann Med Surg (Lond) 2021; 74:102974. [PMID: 34745595 PMCID: PMC8563083 DOI: 10.1016/j.amsu.2021.102974] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 10/14/2021] [Accepted: 10/28/2021] [Indexed: 01/18/2023] Open
Affiliation(s)
- Farah Yasmin
- Department of Internal Medicine, Dow Medical College, Dow University of Health Sciences, Karachi, Pakistan
| | - Muhammad Hamayl Zeeshan
- Department of Internal Medicine, Dow Medical College, Dow University of Health Sciences, Karachi, Pakistan
| | - Irfan Ullah
- Department of Community Medicine, Kabir Medical College (Gandhara University), Peshawar, Pakistan
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7
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Davies SP, Mycroft-West CJ, Pagani I, Hill HJ, Chen YH, Karlsson R, Bagdonaite I, Guimond SE, Stamataki Z, De Lima MA, Turnbull JE, Yang Z, Vicenzi E, Skidmore MA, Khanim FL, Richardson A. The Hyperlipidaemic Drug Fenofibrate Significantly Reduces Infection by SARS-CoV-2 in Cell Culture Models. Front Pharmacol 2021; 12:660490. [PMID: 34421587 PMCID: PMC8377159 DOI: 10.3389/fphar.2021.660490] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 06/28/2021] [Indexed: 12/15/2022] Open
Abstract
The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic has caused a significant number of fatalities and worldwide disruption. To identify drugs to repurpose to treat SARS-CoV-2 infections, we established a screen to measure the dimerization of angiotensin-converting enzyme 2 (ACE2), the primary receptor for the virus. This screen identified fenofibric acid, the active metabolite of fenofibrate. Fenofibric acid also destabilized the receptor-binding domain (RBD) of the viral spike protein and inhibited RBD binding to ACE2 in enzyme-linked immunosorbent assay (ELISA) and whole cell-binding assays. Fenofibrate and fenofibric acid were tested by two independent laboratories measuring infection of cultured Vero cells using two different SARS-CoV-2 isolates. In both settings at drug concentrations, which are clinically achievable, fenofibrate and fenofibric acid reduced viral infection by up to 70%. Together with its extensive history of clinical use and its relatively good safety profile, this study identifies fenofibrate as a potential therapeutic agent requiring an urgent clinical evaluation to treat SARS-CoV-2 infection.
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Affiliation(s)
- Scott P Davies
- Institute for Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
| | - Courtney J Mycroft-West
- Molecular and Structural Bioscience, School of Life Sciences, Keele University, Staffordshire, United Kingdom
| | - Isabel Pagani
- Viral Pathogenesis and Biosafety Unit, San Raffaele Scientific Institute Via Olgettina, Milano, Italy
| | - Harriet J Hill
- Institute for Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
| | - Yen-Hsi Chen
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Richard Karlsson
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Ieva Bagdonaite
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Scott E Guimond
- Molecular and Structural Bioscience, School of Life Sciences, Keele University, Staffordshire, United Kingdom
| | - Zania Stamataki
- Institute for Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
| | - Marcelo Andrade De Lima
- Molecular and Structural Bioscience, School of Life Sciences, Keele University, Staffordshire, United Kingdom
| | - Jeremy E Turnbull
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Zhang Yang
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Elisa Vicenzi
- Viral Pathogenesis and Biosafety Unit, San Raffaele Scientific Institute Via Olgettina, Milano, Italy
| | - Mark A Skidmore
- Molecular and Structural Bioscience, School of Life Sciences, Keele University, Staffordshire, United Kingdom
| | - Farhat L Khanim
- School of Biomedical Sciences, Institute for Clinical Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Alan Richardson
- School of Pharmacy and Bioengineering, Keele University, Staffordshire, United Kingdom
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Chhabra Y, Lee CMM, Müller AF, Brooks AJ. GHR signalling: Receptor activation and degradation mechanisms. Mol Cell Endocrinol 2021; 520:111075. [PMID: 33181235 DOI: 10.1016/j.mce.2020.111075] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 11/01/2020] [Accepted: 11/03/2020] [Indexed: 12/21/2022]
Abstract
Growth hormone (GH) actions via initiating cell signalling through the GH receptor (GHR) are important for many physiological processes, in addition to its well-known role in regulating growth. The activation of JAK-STAT signalling by GH is well characterized, however knowledge on GH activation of SRC family kinases (SFKs) is still limited. In this review we summarise the collective knowledge on the activation, regulation, and downstream signalling of GHR. We highlight studies on GH activation of SFKs and the important outcome of this signalling pathway with a focus on the different degradation mechanisms that can regulate GHR availability since this is an area that warrants further study considering its role in tumour progression.
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Affiliation(s)
- Yash Chhabra
- The University of Queensland Diamantina Institute, The University of Queensland, Woolloongabba, QLD, 4102, Australia; Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, 21231, USA
| | - Christine M M Lee
- The University of Queensland Diamantina Institute, The University of Queensland, Woolloongabba, QLD, 4102, Australia
| | - Alexandra Franziska Müller
- The University of Queensland Diamantina Institute, The University of Queensland, Woolloongabba, QLD, 4102, Australia
| | - Andrew J Brooks
- The University of Queensland Diamantina Institute, The University of Queensland, Woolloongabba, QLD, 4102, Australia.
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Frank SJ. Classical and novel GH receptor signaling pathways. Mol Cell Endocrinol 2020; 518:110999. [PMID: 32835785 PMCID: PMC7799394 DOI: 10.1016/j.mce.2020.110999] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 08/12/2020] [Accepted: 08/17/2020] [Indexed: 12/16/2022]
Abstract
In this review, I summarize historical and recent features of the classical pathways activated by growth hormone (GH) through the cell surface GH receptor (GHR). GHR is a cytokine receptor superfamily member that signals by activating the non-receptor tyrosine kinase, JAK2, and members of the Src family kinases. Activation of the GHR engages STATs, PI3K, and ERK pathways, among others, and details of these now-classical pathways are presented. Modulating elements, including the SOCS proteins, phosphatases, and regulated GHR metalloproteolysis, are discussed. In addition, a novel physical and functional interaction of GHR with IGF-1R is summarized and discussed in terms of its mechanisms, consequences, and physiological and therapeutic implications.
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Affiliation(s)
- Stuart J Frank
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Alabama at Birmingham, Birmingham, 1720 2nd Avenue South, BDB 485, AL, 35294-0012, USA; Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA; Endocrinology Section, Medical Service, Veterans Affairs Medical Center, Birmingham, AL, 35233, USA.
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10
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Strous GJ, Almeida ADS, Putters J, Schantl J, Sedek M, Slotman JA, Nespital T, Hassink GC, Mol JA. Growth Hormone Receptor Regulation in Cancer and Chronic Diseases. Front Endocrinol (Lausanne) 2020; 11:597573. [PMID: 33312162 PMCID: PMC7708378 DOI: 10.3389/fendo.2020.597573] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 10/14/2020] [Indexed: 12/14/2022] Open
Abstract
The GHR signaling pathway plays important roles in growth, metabolism, cell cycle control, immunity, homeostatic processes, and chemoresistance via both the JAK/STAT and the SRC pathways. Dysregulation of GHR signaling is associated with various diseases and chronic conditions such as acromegaly, cancer, aging, metabolic disease, fibroses, inflammation and autoimmunity. Numerous studies entailing the GHR signaling pathway have been conducted for various cancers. Diverse factors mediate the up- or down-regulation of GHR signaling through post-translational modifications. Of the numerous modifications, ubiquitination and deubiquitination are prominent events. Ubiquitination by E3 ligase attaches ubiquitins to target proteins and induces proteasomal degradation or starts the sequence of events that leads to endocytosis and lysosomal degradation. In this review, we discuss the role of first line effectors that act directly on the GHR at the cell surface including ADAM17, JAK2, SRC family member Lyn, Ubc13/CHIP, proteasome, βTrCP, CK2, STAT5b, and SOCS2. Activity of all, except JAK2, Lyn and STAT5b, counteract GHR signaling. Loss of their function increases the GH-induced signaling in favor of aging and certain chronic diseases, exemplified by increased lung cancer risk in case of a mutation in the SOCS2-GHR interaction site. Insight in their roles in GHR signaling can be applied for cancer and other therapeutic strategies.
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Affiliation(s)
- Ger J. Strous
- Department of Cell Biology, Centre for Molecular Medicine, University Medical Centre Utrecht, Utrecht, Netherlands
- BIMINI Biotech B.V., Leiden, Netherlands
| | - Ana Da Silva Almeida
- Department of Cell Biology, Centre for Molecular Medicine, University Medical Centre Utrecht, Utrecht, Netherlands
| | - Joyce Putters
- Department of Cell Biology, Centre for Molecular Medicine, University Medical Centre Utrecht, Utrecht, Netherlands
| | - Julia Schantl
- Department of Cell Biology, Centre for Molecular Medicine, University Medical Centre Utrecht, Utrecht, Netherlands
| | - Magdalena Sedek
- Department of Cell Biology, Centre for Molecular Medicine, University Medical Centre Utrecht, Utrecht, Netherlands
| | - Johan A. Slotman
- Department of Cell Biology, Centre for Molecular Medicine, University Medical Centre Utrecht, Utrecht, Netherlands
| | - Tobias Nespital
- Department of Cell Biology, Centre for Molecular Medicine, University Medical Centre Utrecht, Utrecht, Netherlands
| | - Gerco C. Hassink
- Department of Cell Biology, Centre for Molecular Medicine, University Medical Centre Utrecht, Utrecht, Netherlands
| | - Jan A. Mol
- Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands
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Mohammadian Khonsari N, Mohammad Poor Nami S, Hakak-Zargar B, Voth T. Mutations of uncertain significance in heterozygous variants as a possible cause of severe short stature: a case report. Mol Cell Pediatr 2020; 7:11. [PMID: 32935225 PMCID: PMC7492327 DOI: 10.1186/s40348-020-00104-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 08/25/2020] [Indexed: 11/13/2022] Open
Abstract
Background Linear bone growth is achieved by the division of chondrocytes at the growth plate and is regulated by endocrine and paracrine factors such as growth hormone. Mutations that negatively affect chondrogenesis can be a contributor to short stature. One such mutation can occur in the ACAN gene, causing short stature and advanced bone age. Similarly, mutations in growth hormone receptors (GHR) can lead to Laron syndrome (LS), one of the several disorders that are collectively called growth hormone insensitivity syndrome (GHI). Another example is Floating-Harbor syndrome (FHS), a rare autosomal dominant due to mutations in the SRCAP gene that can also result in short stature. Case presentation We report the case of a 6-year-old female with concomitant mutations in the three genes mentioned above. The mutations reported here were found on genetic studies and are usually benign, causing a variant of undetermined significance. However, our patient’s phenotype could only be explained by the compounded effects of pathogenic mutations of these genes. Some of the same mutations were also found in the patient’s father and her paternal grandfather. Both also presented with short stature, though not to the same degree as our patient. While these mutations are often reported to be insignificant, they gave rise to severe short stature and a specific phenotype in the patient when presented together. We think that even though the GHI spectrum is inherited through an autosomal recessive pattern, the sum of these heterozygous mutations resulted in severe short stature despite the limited GHI seen in our patient, the father, and the grandfather, through a rare ACAN and SRCAP mutation that, to our knowledge, has not been previously reported as a pathogenic mutation in the literature. Conclusion We investigated the possible synergistic effects of these variations on exacerbation or masking of the signs and symptoms of GHI with the hope of providing a better understanding of these genes and their function through our rare case.
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Affiliation(s)
| | | | - Benyamin Hakak-Zargar
- Faculty of Health Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Tessa Voth
- Department of Biomedical Physiology and Kinesiology, Faculty of Science, Simon Fraser University, Burnaby, British Columbia, Canada
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12
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Wilmes S, Hafer M, Vuorio J, Tucker JA, Winkelmann H, Löchte S, Stanly TA, Pulgar Prieto KD, Poojari C, Sharma V, Richter CP, Kurre R, Hubbard SR, Garcia KC, Moraga I, Vattulainen I, Hitchcock IS, Piehler J. Mechanism of homodimeric cytokine receptor activation and dysregulation by oncogenic mutations. Science 2020; 367:643-652. [PMID: 32029621 PMCID: PMC8117407 DOI: 10.1126/science.aaw3242] [Citation(s) in RCA: 94] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 10/08/2019] [Accepted: 12/20/2019] [Indexed: 12/11/2022]
Abstract
Homodimeric class I cytokine receptors are assumed to exist as preformed dimers that are activated by ligand-induced conformational changes. We quantified the dimerization of three prototypic class I cytokine receptors in the plasma membrane of living cells by single-molecule fluorescence microscopy. Spatial and spatiotemporal correlation of individual receptor subunits showed ligand-induced dimerization and revealed that the associated Janus kinase 2 (JAK2) dimerizes through its pseudokinase domain. Oncogenic receptor and hyperactive JAK2 mutants promoted ligand-independent dimerization, highlighting the formation of receptor dimers as the switch responsible for signal activation. Atomistic modeling and molecular dynamics simulations based on a detailed energetic analysis of the interactions involved in dimerization yielded a mechanistic blueprint for homodimeric class I cytokine receptor activation and its dysregulation by individual mutations.
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Affiliation(s)
- Stephan Wilmes
- Department of Biology and Center of Cellular Nanoanalytics, University of Osnabrück, 49076 Osnabrück, Germany
- Division of Cell Signalling and Immunology, School of Life Sciences, University of Dundee, Dundee, UK
| | - Maximillian Hafer
- Department of Biology and Center of Cellular Nanoanalytics, University of Osnabrück, 49076 Osnabrück, Germany
| | - Joni Vuorio
- Department of Physics, University of Helsinki, Helsinki, Finland
- Computational Physics Laboratory, Tampere University, Tampere, Finland
| | - Julie A Tucker
- York Biomedical Research Institute and Department of Biology, University of York, Heslington, York YO10 5DD, UK
| | - Hauke Winkelmann
- Department of Biology and Center of Cellular Nanoanalytics, University of Osnabrück, 49076 Osnabrück, Germany
| | - Sara Löchte
- Department of Biology and Center of Cellular Nanoanalytics, University of Osnabrück, 49076 Osnabrück, Germany
| | - Tess A Stanly
- York Biomedical Research Institute and Department of Biology, University of York, Heslington, York YO10 5DD, UK
| | - Katiuska D Pulgar Prieto
- York Biomedical Research Institute and Department of Biology, University of York, Heslington, York YO10 5DD, UK
| | - Chetan Poojari
- Department of Physics, University of Helsinki, Helsinki, Finland
| | - Vivek Sharma
- Department of Physics, University of Helsinki, Helsinki, Finland
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Christian P Richter
- Department of Biology and Center of Cellular Nanoanalytics, University of Osnabrück, 49076 Osnabrück, Germany
| | - Rainer Kurre
- Department of Biology and Center of Cellular Nanoanalytics, University of Osnabrück, 49076 Osnabrück, Germany
| | - Stevan R Hubbard
- Skirball Institute and Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
| | - K Christopher Garcia
- Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA, USA
- Department of Molecular and Cellular Physiology and Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Ignacio Moraga
- Division of Cell Signalling and Immunology, School of Life Sciences, University of Dundee, Dundee, UK
| | - Ilpo Vattulainen
- Department of Physics, University of Helsinki, Helsinki, Finland.
- Computational Physics Laboratory, Tampere University, Tampere, Finland
| | - Ian S Hitchcock
- York Biomedical Research Institute and Department of Biology, University of York, Heslington, York YO10 5DD, UK.
| | - Jacob Piehler
- Department of Biology and Center of Cellular Nanoanalytics, University of Osnabrück, 49076 Osnabrück, Germany.
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13
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Botta J, Appelhans J, McCormick PJ. Continuing challenges in targeting oligomeric GPCR-based drugs. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2020; 169:213-245. [DOI: 10.1016/bs.pmbts.2019.11.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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14
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T618I CSF3R mutations in chronic neutrophilic leukemia induce oncogenic signals through aberrant trafficking and constitutive phosphorylation of the O-glycosylated receptor form. Biochem Biophys Res Commun 2019; 523:208-213. [PMID: 31848046 DOI: 10.1016/j.bbrc.2019.12.030] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 12/05/2019] [Indexed: 12/19/2022]
Abstract
Activating mutations in the membrane-proximal region of the colony-stimulating factor 3 receptor (CSF3R) are a hallmark of chronic neutrophilic leukemia (CNL) with the T618I mutation being most common. The mechanisms underlying constitutive activation of the T618I CSF3R and its signal propagation are poorly understood. Ligand-independent activation of the T618I CSF3R has previously been attributed to loss of receptor O-glycosylation and increased receptor dimerization. Here, we show that the T618I CSF3R is indeed glycosylated but undergoes enhanced spontaneous internalization and degradation that results in a marked decrease in its surface expression. Inhibition of the proteasome dramatically increases expression of the O-glycosylated T618I CSF3R. We also demonstrate that the O-glycosylated wild-type CSF3R is tyrosine phosphorylated in response to ligand but constitutively phosphorylated in cells expressing T618I CSF3R. Constitutive tyrosine phosphorylation of the O-glycosylated T618I receptor form correlated with activation of JAK2 and both the mutant receptor and JAK2 were found to be constitutively ubiquitinated. These observations provide novel insights into the mechanisms of oncogenic signaling by T618I CSF3R mutations in CNL.
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15
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Storr HL, Chatterjee S, Metherell LA, Foley C, Rosenfeld RG, Backeljauw PF, Dauber A, Savage MO, Hwa V. Nonclassical GH Insensitivity: Characterization of Mild Abnormalities of GH Action. Endocr Rev 2019; 40:476-505. [PMID: 30265312 PMCID: PMC6607971 DOI: 10.1210/er.2018-00146] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 07/31/2018] [Indexed: 12/12/2022]
Abstract
GH insensitivity (GHI) presents in childhood with growth failure and in its severe form is associated with extreme short stature and dysmorphic and metabolic abnormalities. In recent years, the clinical, biochemical, and genetic characteristics of GHI and other overlapping short stature syndromes have rapidly expanded. This can be attributed to advancing genetic techniques and a greater awareness of this group of disorders. We review this important spectrum of defects, which present with phenotypes at the milder end of the GHI continuum. We discuss their clinical, biochemical, and genetic characteristics. The objective of this review is to clarify the definition, identification, and investigation of this clinically relevant group of growth defects. We also review the therapeutic challenges of mild GHI.
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Affiliation(s)
- Helen L Storr
- Centre for Endocrinology, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, United Kingdom
| | - Sumana Chatterjee
- Centre for Endocrinology, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, United Kingdom
| | - Louise A Metherell
- Centre for Endocrinology, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, United Kingdom
| | - Corinne Foley
- Division of Endocrinology, Cincinnati Center for Growth Disorders, Cincinnati Children’s Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Ron G Rosenfeld
- Department of Pediatrics, Oregon Health and Science University, Portland, Oregon
| | - Philippe F Backeljauw
- Division of Endocrinology, Cincinnati Center for Growth Disorders, Cincinnati Children’s Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Andrew Dauber
- Division of Endocrinology, Cincinnati Center for Growth Disorders, Cincinnati Children’s Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Martin O Savage
- Centre for Endocrinology, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, United Kingdom
| | - Vivian Hwa
- Division of Endocrinology, Cincinnati Center for Growth Disorders, Cincinnati Children’s Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, Ohio
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16
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Zabeau L, Wauman J, Dam J, Van Lint S, Burg E, De Geest J, Rogge E, Silva A, Jockers R, Tavernier J. A novel leptin receptor antagonist uncouples leptin's metabolic and immune functions. Cell Mol Life Sci 2019; 76:1201-1214. [PMID: 30659329 PMCID: PMC11105424 DOI: 10.1007/s00018-019-03004-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 12/28/2018] [Accepted: 01/02/2019] [Indexed: 12/19/2022]
Abstract
Leptin links body energy stores to high energy demanding processes like reproduction and immunity. Based on leptin's role in autoimmune diseases and cancer, several leptin and leptin receptor (LR) antagonists have been developed, but these intrinsically lead to unwanted weight gain. Here, we report on the uncoupling of leptin's metabolic and immune functions based on the cross talk with the epidermal growth factor receptor (EGFR). We show that both receptors spontaneously interact and, remarkably, that this complex can partially overrule the lack of LR activation by a leptin antagonistic mutein. Moreover, this leptin mutant induces EGFR phosphorylation comparable to wild-type leptin. Exploiting this non-canonical leptin signalling pathway, we identified a camelid single-domain antibody that selectively inhibits this LR-EGFR cross talk without interfering with homotypic LR signalling. Administration in vivo showed that this single-domain antibody did not interfere with leptin's metabolic functions, but could reverse the leptin-driven protection against starvation-induced thymic and splenic atrophy. These findings offer new opportunities for the design and clinical application of selective leptin and LR antagonists that avoid unwanted metabolic side effects.
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Affiliation(s)
- Lennart Zabeau
- Faculty of Medicine and Health Sciences, VIB-UGent Center for Medical Biotechnology, Flanders Institute for Biotechnology, Ghent University, A. Baertsoenkaai 3, 9000, Ghent, Belgium
| | - Joris Wauman
- Faculty of Medicine and Health Sciences, VIB-UGent Center for Medical Biotechnology, Flanders Institute for Biotechnology, Ghent University, A. Baertsoenkaai 3, 9000, Ghent, Belgium
| | - Julie Dam
- Inserm U1016, CNRS UMR 8104, Univ. Paris Descartes, Sorbonne Paris Cité, Institut Cochin, 22 rue Méchain, 75014, Paris, France
| | - Sandra Van Lint
- Faculty of Medicine and Health Sciences, VIB-UGent Center for Medical Biotechnology, Flanders Institute for Biotechnology, Ghent University, A. Baertsoenkaai 3, 9000, Ghent, Belgium
| | - Elianne Burg
- Faculty of Medicine and Health Sciences, VIB-UGent Center for Medical Biotechnology, Flanders Institute for Biotechnology, Ghent University, A. Baertsoenkaai 3, 9000, Ghent, Belgium
| | - Jennifer De Geest
- Faculty of Medicine and Health Sciences, VIB-UGent Center for Medical Biotechnology, Flanders Institute for Biotechnology, Ghent University, A. Baertsoenkaai 3, 9000, Ghent, Belgium
| | - Elke Rogge
- Faculty of Medicine and Health Sciences, VIB-UGent Center for Medical Biotechnology, Flanders Institute for Biotechnology, Ghent University, A. Baertsoenkaai 3, 9000, Ghent, Belgium
| | - Anisia Silva
- Inserm U1016, CNRS UMR 8104, Univ. Paris Descartes, Sorbonne Paris Cité, Institut Cochin, 22 rue Méchain, 75014, Paris, France
| | - Ralf Jockers
- Inserm U1016, CNRS UMR 8104, Univ. Paris Descartes, Sorbonne Paris Cité, Institut Cochin, 22 rue Méchain, 75014, Paris, France
| | - Jan Tavernier
- Faculty of Medicine and Health Sciences, VIB-UGent Center for Medical Biotechnology, Flanders Institute for Biotechnology, Ghent University, A. Baertsoenkaai 3, 9000, Ghent, Belgium.
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17
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Yang Q, Wang L, He J, Wei H, Yang Z, Huang X. Arabinogalactan Proteins Are the Possible Extracellular Molecules for Binding Exogenous Cerium(III) in the Acidic Environment Outside Plant Cells. FRONTIERS IN PLANT SCIENCE 2019; 10:153. [PMID: 30842782 PMCID: PMC6391350 DOI: 10.3389/fpls.2019.00153] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Accepted: 01/29/2019] [Indexed: 05/29/2023]
Abstract
Rare earth elements [REE(III)] increasingly accumulate in the atmosphere and can be absorbed by plant leaves. Our previous study showed that after treatment of REE(III) on plant, REE(III) is first bound by some extracellular molecules of plant cells, and then the endocytosis of leaf cells will be initiated, which terminates the endocytic inertia of leaf cells. Identifying the extracellular molecules for binding REE(III) is the crucial first step to elucidate the mechanism of REE(III) initiating the endocytosis in leaf cells. Unfortunately, the molecules are unknown. Here, cerium(III) [Ce(III)] and Arabidopsis served as a representative of REE(III) and plants, respectively. By using interdisciplinary methods such as confocal laser scanning microscopy, immune-Au and fluorescent labeling, transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), ultraviolet-visible spectroscopy, circular dichroism spectroscopy, fluorescent spectrometry and molecular dynamics simulation, we obtained two important discoveries: first, the arabinogalactan proteins (AGP) inside leaf cells were sensitively increased in protein expression and recruited onto the plasma membrane; second, to verify whether AGP can bind to Ce(III) in the acidic environment outside leaf cells, by choosing fasciclin-like AGP11 (AtFLA11) as a representative of AGP, we found that Ce(III) can form stable [Ce(H2O)7](III)-AtFLA11 complexes with an apparent binding constant of 1.44 × 10-6 in simulated acidic environment outside leaf cells, in which the secondary and tertiary structure of AtFLA11 was changed. The structural change in AtFLA11 and the interaction between AtFLA11 and Ce(III) were enhanced with increasing the concentration of Ce(III). Therefore, AtFLA11 can serve as Lewis bases to coordinately bind to Ce(III), which broke traditional chemical principle. The results confirmed that AGP can be the possible extracellular molecules for binding to exogenous Ce(III) outside leaf cells, and provided references for elucidating the mechanism of REE(III) initiating the endocytosis in leaf cells.
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Affiliation(s)
- Qing Yang
- National and Local Joint Engineering Research Center of Biomedical Functional Materials, Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing, China
| | - Lihong Wang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China
| | - Jingfang He
- National and Local Joint Engineering Research Center of Biomedical Functional Materials, Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing, China
| | - Haiyan Wei
- National and Local Joint Engineering Research Center of Biomedical Functional Materials, Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing, China
| | - Zhenbiao Yang
- Center for Plant Cell Biology, Institute for Integrative Genome Biology, University of California, Riverside, Riverside, CA, United States
| | - Xiaohua Huang
- National and Local Joint Engineering Research Center of Biomedical Functional Materials, Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing, China
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18
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Gorby C, Martinez-Fabregas J, Wilmes S, Moraga I. Mapping Determinants of Cytokine Signaling via Protein Engineering. Front Immunol 2018; 9:2143. [PMID: 30319612 PMCID: PMC6170656 DOI: 10.3389/fimmu.2018.02143] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 08/30/2018] [Indexed: 12/21/2022] Open
Abstract
Cytokines comprise a large family of secreted ligands that are critical for the regulation of immune homeostasis. Cytokines initiate signaling via dimerization or oligomerization of the cognate receptor subunits, triggering the activation of the Janus Kinases (JAKs)/ signal transducer and activator of transcription (STATs) pathway and the induction of specific gene expression programs and bioactivities. Deregulation of cytokines or their downstream signaling pathways are at the root of many human disorders including autoimmunity and cancer. Identifying and understanding the mechanistic principles that govern cytokine signaling will, therefore, be highly important in order to harness the therapeutic potential of cytokines. In this review, we will analyze how biophysical (ligand-receptor binding geometry and affinity) and cellular (receptor trafficking and intracellular abundance of signaling molecules) parameters shape the cytokine signalosome and cytokine functional pleiotropy; from the initial cytokine binding to its receptor to the degradation of the cytokine receptor complex in the proteasome and/or lysosome. We will also discuss how combining advanced protein engineering with detailed signaling and functional studies has opened promising avenues to tackle complex questions in the cytokine signaling field.
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Affiliation(s)
- Claire Gorby
- Division of Cell Signaling and Immunology, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Jonathan Martinez-Fabregas
- Division of Cell Signaling and Immunology, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Stephan Wilmes
- Division of Cell Signaling and Immunology, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Ignacio Moraga
- Division of Cell Signaling and Immunology, School of Life Sciences, University of Dundee, Dundee, United Kingdom
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19
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Mazziotti G, Frara S, Giustina A. Pituitary Diseases and Bone. Endocr Rev 2018; 39:440-488. [PMID: 29684108 DOI: 10.1210/er.2018-00005] [Citation(s) in RCA: 95] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Accepted: 04/16/2018] [Indexed: 12/12/2022]
Abstract
Neuroendocrinology of bone is a new area of research based on the evidence that pituitary hormones may directly modulate bone remodeling and metabolism. Skeletal fragility associated with high risk of fractures is a common complication of several pituitary diseases such as hypopituitarism, Cushing disease, acromegaly, and hyperprolactinemia. As in other forms of secondary osteoporosis, pituitary diseases generally affect bone quality more than bone quantity, and fractures may occur even in the presence of normal or low-normal bone mineral density as measured by dual-energy X-ray absorptiometry, making difficult the prediction of fractures in these clinical settings. Treatment of pituitary hormone excess and deficiency generally improves skeletal health, although some patients remain at high risk of fractures, and treatment with bone-active drugs may become mandatory. The aim of this review is to discuss the physiological, pathophysiological, and clinical insights of bone involvement in pituitary diseases.
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Affiliation(s)
| | - Stefano Frara
- Institute of Endocrinology, Università Vita-Salute San Raffaele, Milan, Italy
| | - Andrea Giustina
- Institute of Endocrinology, Università Vita-Salute San Raffaele, Milan, Italy
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20
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Berry R, McGinnis GR, Banerjee RR, Young ME, Frank SJ. Differential tissue response to growth hormone in mice. FEBS Open Bio 2018; 8:1146-1154. [PMID: 29988606 PMCID: PMC6026699 DOI: 10.1002/2211-5463.12444] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 04/11/2018] [Accepted: 05/02/2018] [Indexed: 12/29/2022] Open
Abstract
Growth hormone (GH) has been shown to act directly on multiple tissues throughout the body. Historically, it was believed that GH acted directly in the liver and only indirectly in other tissues via insulin-like growth hormone 1 (IGF-1). Despite extensive work to describe GH action in individual tissues, a comparative analysis of acute GH signaling in key metabolic tissues has not been performed. Herein, we address this knowledge gap. Acute tissue response to human recombinant GH was assessed in mice by measuring signaling via phospho-STAT5 immunoblotting. STAT5 activation is an easily and reliably detected early marker of GH receptor engagement. We found differential tissue sensitivities; liver and kidney were equally GH-sensitive and more sensitive than white adipose tissue, heart, and muscle (gastrocnemius). Gastrocnemius had the greatest maximal response compared to heart, liver, white adipose tissue, and whole kidney. Differences in maximum responsiveness were positively correlated with tissue STAT5 abundance, while differences in sensitivity were not explained by differences in GH receptor levels. Thus, GH sensitivity and responsiveness of distinct metabolic tissues differ and may impact physiology and disease.
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Affiliation(s)
- Ryan Berry
- Department of MedicineDivision of Endocrinology, Diabetes, and MetabolismUniversity of Alabama at BirminghamALUSA
| | - Graham R. McGinnis
- Department of MedicineDivision of Cardiovascular DiseaseUniversity of Alabama at BirminghamALUSA
| | - Ronadip R. Banerjee
- Department of MedicineDivision of Endocrinology, Diabetes, and MetabolismUniversity of Alabama at BirminghamALUSA
| | - Martin E. Young
- Department of MedicineDivision of Cardiovascular DiseaseUniversity of Alabama at BirminghamALUSA
| | - Stuart J. Frank
- Department of MedicineDivision of Endocrinology, Diabetes, and MetabolismUniversity of Alabama at BirminghamALUSA
- Department of Cell, Developmental, and Integrative BiologyUniversity of Alabama at BirminghamALUSA
- Endocrinology SectionMedical ServiceVeterans Affairs Medical CenterBirminghamALUSA
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21
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Wójcik M, Krawczyńska A, Antushevich H, Herman AP. Post-Receptor Inhibitors of the GHR-JAK2-STAT Pathway in the Growth Hormone Signal Transduction. Int J Mol Sci 2018; 19:E1843. [PMID: 29932147 PMCID: PMC6073700 DOI: 10.3390/ijms19071843] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Revised: 06/15/2018] [Accepted: 06/19/2018] [Indexed: 02/06/2023] Open
Abstract
The growth hormone (GH) plays a key role in the regulation of metabolic processes in an organism. Determination of the correct structure and functioning of the growth hormone receptor (GHR) allowed for a more detailed research of its post-receptor regulators, which substantially influences its signal transduction. This review is focused on the description of the post-receptor inhibitors of the GHR-JAK2-STAT pathway, which is one of the most important pathways in the transduction of the somatotropic axis signal. The aim of this review is the short characterization of the main post-receptor inhibitors, such as: cytokine-inducible SH2-containing protein (CIS), Suppressors of Cytokine Signaling (SOCS) 1, 2 and 3, sirtuin 1 (SIRT1), protein inhibitors of activated STAT (PIAS) 1, 3 and PIAS4, protein tyrosine phosphatases (PTP) 1B and H1, Src homology 2 (SH2) domain containing protein tyrosine phosphatase (SHP) 1, 2 and signal regulatory protein (SIRP) α1. The equilibrium between these regulators activity and inhibition is of special concern because, as many studies showed, even slight imbalance may disrupt the GH activity causing serious diseases. The regulation of the described inhibitors expression and activity may be a point of interest for pharmaceutical industry.
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Affiliation(s)
- Maciej Wójcik
- The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, ul. Instytucka 3, 05-110 Jabłonna, Poland.
| | - Agata Krawczyńska
- The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, ul. Instytucka 3, 05-110 Jabłonna, Poland.
| | - Hanna Antushevich
- The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, ul. Instytucka 3, 05-110 Jabłonna, Poland.
| | - Andrzej Przemysław Herman
- The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, ul. Instytucka 3, 05-110 Jabłonna, Poland.
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22
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Growth Hormone Receptor Mutations Related to Individual Dwarfism. Int J Mol Sci 2018; 19:ijms19051433. [PMID: 29748515 PMCID: PMC5983672 DOI: 10.3390/ijms19051433] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Revised: 04/20/2018] [Accepted: 05/07/2018] [Indexed: 12/21/2022] Open
Abstract
Growth hormone (GH) promotes body growth by binding with two GH receptors (GHRs) at the cell surface. GHRs interact with Janus kinase, signal transducers, and transcription activators to stimulate metabolic effects and insulin-like growth factor (IGF) synthesis. However, process dysfunctions in the GH⁻GHR⁻IGF-1 axis cause animal dwarfism. If, during the GH process, GHR is not successfully recognized and/or bound, or GHR fails to transmit the GH signal to IGF-1, the GH dysfunction occurs. The goal of this review was to focus on the GHR mutations that lead to failures in the GH⁻GHR⁻IGF-1 signal transaction process in the dwarf phenotype. Until now, more than 90 GHR mutations relevant to human short stature (Laron syndrome and idiopathic short stature), including deletions, missense, nonsense, frameshift, and splice site mutations, and four GHR defects associated with chicken dwarfism, have been described. Among the 93 identified mutations of human GHR, 68 occur extracellularly, 13 occur in GHR introns, 10 occur intracellularly, and two occur in the transmembrane. These mutations interfere with the interaction between GH and GHRs, GHR dimerization, downstream signaling, and the expression of GHR. These mutations cause aberrant functioning in the GH-GHR-IGF-1 axis, resulting in defects in the number and diameter of muscle fibers as well as bone development.
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23
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Dehkhoda F, Lee CMM, Medina J, Brooks AJ. The Growth Hormone Receptor: Mechanism of Receptor Activation, Cell Signaling, and Physiological Aspects. Front Endocrinol (Lausanne) 2018; 9:35. [PMID: 29487568 PMCID: PMC5816795 DOI: 10.3389/fendo.2018.00035] [Citation(s) in RCA: 160] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 01/29/2018] [Indexed: 01/02/2023] Open
Abstract
The growth hormone receptor (GHR), although most well known for regulating growth, has many other important biological functions including regulating metabolism and controlling physiological processes related to the hepatobiliary, cardiovascular, renal, gastrointestinal, and reproductive systems. In addition, growth hormone signaling is an important regulator of aging and plays a significant role in cancer development. Growth hormone activates the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) signaling pathway, and recent studies have provided a new understanding of the mechanism of JAK2 activation by growth hormone binding to its receptor. JAK2 activation is required for growth hormone-mediated activation of STAT1, STAT3, and STAT5, and the negative regulation of JAK-STAT signaling comprises an important step in the control of this signaling pathway. The GHR also activates the Src family kinase signaling pathway independent of JAK2. This review covers the molecular mechanisms of GHR activation and signal transduction as well as the physiological consequences of growth hormone signaling.
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Affiliation(s)
- Farhad Dehkhoda
- The University of Queensland Diamantina Institute, Translational Research Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Christine M. M. Lee
- The University of Queensland Diamantina Institute, Translational Research Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Johan Medina
- The University of Queensland Diamantina Institute, Translational Research Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Andrew J. Brooks
- The University of Queensland Diamantina Institute, Translational Research Institute, The University of Queensland, Brisbane, QLD, Australia
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24
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Moia S, Tessaris D, Einaudi S, de Sanctis L, Bona G, Bellone S, Prodam F. Compound heterozygosity for two GHR missense mutations in a patient affected by Laron Syndrome: a case report. Ital J Pediatr 2017; 43:94. [PMID: 29025428 PMCID: PMC5639735 DOI: 10.1186/s13052-017-0411-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 09/26/2017] [Indexed: 11/25/2022] Open
Abstract
Background Mutations localized in the Growth Hormone Receptor (GHR) gene are often associated with the pathogenesis of Laron Syndrome, an autosomal recessive hereditary disorder characterized by severe growth retardation. Biochemically, patients present normal to high circulating GH levels, in presence of very low or undetectable IGF-I levels, which do not rise after rhGH treatment. Case presentation We describe the case of a 3.8 years old girl with symmetrical short stature (−3.76 SDS), low IGF-1 and IGFBP-3, in presence of normal GH levels. Parents were not relatives and there was no family history of short stature. During the second day of birth, she developed severe hypoglycaemia that required glucose infusion. She presented frontal bossing and depressed nasal bridge. IGF-1 generation test showed no response, suggesting a GH resistance evidence. In the hypothesis of Laron Syndrome, we decided to perform a molecular analysis of Growth Hormone Receptor (GHR) gene. This analysis demonstrated that the patient was compound heterozygote for two missense mutations. Conclusions GHR gene mutations are a well demonstrated cause of GH insensitivity. In heterozygous patients, probably the normal stature may be achieved by a compensatory mechanism of GH secretion or signalling. On the contrary, in homozygous or compound heterozygous patients these compensatory mechanisms are inadequate, and short stature may be the consequence.
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Affiliation(s)
- Stefania Moia
- Division of Pediatrics, Department of Health Sciences, University of Piemonte Orientale, Novara, Italy
| | - Daniele Tessaris
- Pediatric Endocrinology, Regina Margherita Children Hospital, University of Turin, Torino, Italy
| | - Silvia Einaudi
- Pediatric Endocrinology, Regina Margherita Children Hospital, University of Turin, Torino, Italy
| | - Luisa de Sanctis
- Pediatric Endocrinology, Regina Margherita Children Hospital, University of Turin, Torino, Italy
| | - Gianni Bona
- Division of Pediatrics, Department of Health Sciences, University of Piemonte Orientale, Novara, Italy
| | - Simonetta Bellone
- Division of Pediatrics, Department of Health Sciences, University of Piemonte Orientale, Novara, Italy
| | - Flavia Prodam
- Division of Pediatrics, Department of Health Sciences, University of Piemonte Orientale, Novara, Italy. .,Division of Endocrinology, Department of Translational Medicine, University of Piemonte Orientale, Novara, Italy.
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Liu Y, Jiang J, Lepik B, Zhang Y, Zinn KR, Frank SJ. Subdomain 2, Not the Transmembrane Domain, Determines the Dimerization Partner of Growth Hormone Receptor and Prolactin Receptor. Endocrinology 2017; 158:3235-3248. [PMID: 28977606 PMCID: PMC5659695 DOI: 10.1210/en.2017-00469] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 07/27/2017] [Indexed: 01/09/2023]
Abstract
Growth hormone receptor (GHR) and prolactin (PRL) receptor (PRLR) are homologous transmembrane class I cytokine receptors. In humans, GH interacts with GHR homodimers or PRLR homodimers and PRL interacts with only PRLR homodimers to promote signaling. In human breast cancer cells endogenously expressing both receptors, GHR and PRLR specifically coimmunoprecipitate. We previously devised a split luciferase complementation assay to study GHR and PRLR assemblages. In this technique, firefly luciferase is split into two fragments (N- and C-terminal fragments of the luciferase), each without enzyme activity and tethered to the tails of two receptors. The fragments restore luciferase activity when brought close to each other by the receptors. Real-time ligand-induced complementation changes reflect the arrangement of receptors and indicate that GHR/PRLR is arranged as a heteromultimer comprised of GHR-GHR homodimers and PRLR-PRLR homodimers. We now dissect determinants for GHR and PRLR homodimerization versus heteroassociation. GHR and PRLR have extracellular domains comprised of the ligand-binding N-terminal subdomain 1 and a membrane-proximal subdomain 2 (S2), which fosters receptor-receptor contact. Based on previous studies of S2 versus the transmembrane domain (TMD) in GHR dimerization, we constructed GHR(PRLRS2), GHR(PRLRS2-TMD), and GHR(PRLRTMD), replacing GHR's S2 alone, S2 plus TMD, and TMD alone with PRLR's counterpart. We tested by complementation the ability of these chimeras and GHR or PRLR to homodimerize or heteroassociate. Comparing various combinations, we found GHR(PRLRS2) and GHR(PRLRS2-TMD) behaved as PRLR, whereas GHR(PRLRTMD) behaved as GHR regarding their dimerization partners. We conclude that S2 of GHR and PRLR, rather than their TMDs, determines their dimerization partner.
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Affiliation(s)
- Ying Liu
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Jing Jiang
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Bradford Lepik
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Yue Zhang
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Kurt R. Zinn
- Department of Radiology, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Stuart J. Frank
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Alabama at Birmingham, Birmingham, Alabama 35294
- Endocrinology Section, Medical Service, Veterans Affairs Medical Center, Birmingham, Alabama 35233
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama 35294
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Timmermans-Sprang EPM, Gracanin A, Mol JA. Molecular Signaling of Progesterone, Growth Hormone, Wnt, and HER in Mammary Glands of Dogs, Rodents, and Humans: New Treatment Target Identification. Front Vet Sci 2017; 4:53. [PMID: 28451590 PMCID: PMC5389977 DOI: 10.3389/fvets.2017.00053] [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: 09/01/2016] [Accepted: 03/28/2017] [Indexed: 12/21/2022] Open
Abstract
Mammary tumors are the most common form of neoplasia in the bitch. Female dogs are protected when they are spayed before the first estrus cycle, but this effect readily disappears and is already absent when dogs are spayed after the second heat. As the ovaries are removed during spaying, ovarian steroids are assumed to play an essential role in tumor development. The sensitivity toward tumor development is already present during early life, which may be caused by early mutations in stem cells during the first estrus cycles. Later on in life, tumors arise that are mostly steroid-receptor positive, although a small subset of tumors overexpressing human epidermal growth factor 2 (HER2) and some lacking estrogen receptor, progesterone receptor (PR), and HER2 (triple negative) are present, as is the situation in humans. Progesterone (P4), acting through PR, is the major steroid involved in outgrowth of mammary tissue. PRs are expressed in two forms, the progesterone receptor A (PRA) and progesterone receptor B (PRB) isoforms derived from splice variants from a single gene. The dog and the whole family of canids have only a functional PRA isoform, whereas the PRB isoform, if expressed at all, is devoid of intrinsic biological activity. In human breast cancer, overexpression of the PRA isoform is related to more aggressive carcinomas making the dog a unique model to study PRA-related mammary cancer. Administration of P4 to adult dogs results in local mammary expression of growth hormone (GH) and wing less-type mouse mammary tumor virus integration site family 4 (Wnt4). Both proteins play a role in activation of mammary stem cells. In this review, we summarize what is known on P4, GH, and Wnt signaling in canine mammary cancer, how the family of HER receptors could interact with this signaling, and what this means for comparative and translational oncological aspects of human breast cancer development.
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Affiliation(s)
| | - Ana Gracanin
- Department of Clinical Sciences of Companion Animals, Utrecht University, Utrecht, Netherlands
| | - Jan A Mol
- Department of Clinical Sciences of Companion Animals, Utrecht University, Utrecht, Netherlands
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Vairamani K, Merjaneh L, Casano-Sancho P, Sanli ME, David A, Metherell LA, Savage MO, Del Pozo JS, Backeljauw PF, Rosenfeld RG, Aisenberg J, Dauber A, Hwa V. Novel Dominant-Negative GH Receptor Mutations Expands the Spectrum of GHI and IGF-I Deficiency. J Endocr Soc 2017; 1:345-358. [PMID: 29188236 PMCID: PMC5686656 DOI: 10.1210/js.2016-1119] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Context: Autosomal-recessive mutations in the growth hormone receptor (GHR) are the most common causes for primary growth hormone insensitivity (GHI) syndrome with classical GHI phenotypically characterized by severe short stature and marked insulin-like growth factor (IGF)-I deficiency. We report three families with dominant-negative heterozygous mutations in the intracellular domain of the GHR causing a nonclassical GHI phenotype. Objective: To determine if the identified GHR heterozygous variants exert potential dominant-negative effects and are the cause for the GHI phenotype in our patients. Results: All three mutations (c.964dupG, c.920_921insTCTCAAAGATTACA, and c.945+2T>C) are predicted to result in frameshift and early protein termination. In vitro functional analysis of variants c.964dupG and c.920_921insTCTCAAAGATTACA (c.920_921ins14) suggests that these variants are expressed as truncated proteins and, when coexpressed with wild-type GHR, mimicking the heterozygous state in our patients, exert dominant-negative effects. Additionally, we provide evidence that a combination therapy of recombinant human growth hormone (rhGH) and rhIGF-I improved linear growth to within normal range for one of our previously reported patients with a characterized, dominant-negative GHR (c.899dupC) mutation. Conclusion: Dominant-negative GHR mutations are causal of the mild GHI with substantial growth failure observed in our patients. Heterozygous defects in the intracellular domain of GHR should, therefore, be considered in cases of idiopathic short stature and IGF-I deficiency. Combination therapy of rhGH and rhIGF-I improved growth in one of our patients.
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Affiliation(s)
- Kanimozhi Vairamani
- Cincinnati Center for Growth Disorders, Division of Endocrinology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229
| | - Lina Merjaneh
- Division of Endocrinology & Diabetes, Seattle Children's Hospital, Seattle, Washington 98105
| | - Paula Casano-Sancho
- Division of Pediatric Endocrinology, Sant Joan de Déu Hospital, Center in Diabetes and Associated Metabolic Disorders, 08950 Barcelona, Spain
| | - Merve Emecen Sanli
- Cincinnati Center for Growth Disorders, Division of Endocrinology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229
| | - Alessia David
- Centre for Bioinformatics and System Biology, Department of Life Sciences, Imperial College London, London, SW7 2AZ, United Kingdom
| | - Louise A Metherell
- Centre for Endocrinology, William Harvey Research Institute, John Vane Science Centre, Queen Mary, University of London, Charterhouse Square, London, EC1M 6BQ, United Kingdom
| | - Martin O Savage
- Centre for Endocrinology, William Harvey Research Institute, John Vane Science Centre, Queen Mary, University of London, Charterhouse Square, London, EC1M 6BQ, United Kingdom
| | - Jaime Sánchez Del Pozo
- Pediatric Endocrinology and Dysmorphology Unit, Hospital 12 de Octubre, 28041 Madrid, Spain
| | - Philippe F Backeljauw
- Cincinnati Center for Growth Disorders, Division of Endocrinology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229
| | - Ron G Rosenfeld
- Department of Pediatrics, Oregon Health & Science University, Portland, Oregon 97239
| | - Javier Aisenberg
- Pediatrics Endocrinology, Hackensack University Medical Center, Hackensack, New Jersey 07601
| | - Andrew Dauber
- Cincinnati Center for Growth Disorders, Division of Endocrinology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229
| | - Vivian Hwa
- Cincinnati Center for Growth Disorders, Division of Endocrinology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229
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Wauman J, Zabeau L, Tavernier J. The Leptin Receptor Complex: Heavier Than Expected? Front Endocrinol (Lausanne) 2017; 8:30. [PMID: 28270795 PMCID: PMC5318964 DOI: 10.3389/fendo.2017.00030] [Citation(s) in RCA: 103] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 02/01/2017] [Indexed: 12/31/2022] Open
Abstract
Under normal physiological conditions, leptin and the leptin receptor (ObR) regulate the body weight by balancing food intake and energy expenditure. However, this adipocyte-derived hormone also directs peripheral processes, including immunity, reproduction, and bone metabolism. Leptin, therefore, can act as a metabolic switch connecting the body's nutritional status to high energy consuming processes. We provide an extensive overview of current structural insights on the leptin-ObR interface and ObR activation, coupling to signaling pathways and their negative regulation, and leptin functioning under normal and pathophysiological conditions (obesity, autoimmunity, cancer, … ). We also discuss possible cross-talk with other receptor systems on the receptor (extracellular) and signaling cascade (intracellular) levels.
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Affiliation(s)
- Joris Wauman
- Cytokine Receptor Laboratory, Faculty of Medicine and Health Sciences, Department of Biochemistry, Ghent University, Ghent, Belgium
- VIB Medical Biotechnology Center, VIB, Ghent, Belgium
| | - Lennart Zabeau
- Cytokine Receptor Laboratory, Faculty of Medicine and Health Sciences, Department of Biochemistry, Ghent University, Ghent, Belgium
- VIB Medical Biotechnology Center, VIB, Ghent, Belgium
| | - Jan Tavernier
- Cytokine Receptor Laboratory, Faculty of Medicine and Health Sciences, Department of Biochemistry, Ghent University, Ghent, Belgium
- VIB Medical Biotechnology Center, VIB, Ghent, Belgium
- *Correspondence: Jan Tavernier,
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Kopchick JJ. Lessons learned from studies with the growth hormone receptor. Growth Horm IGF Res 2016; 28:21-25. [PMID: 26216709 DOI: 10.1016/j.ghir.2015.06.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 06/02/2015] [Indexed: 11/17/2022]
Abstract
Findings related to GH's biological activities have continued to be a fascinating topic over the past decade. Below, I will review several items related to the actions of GH including the GH/GHR interaction, pegvisomant (a GH receptor antagonist), GHR gene disruptions in mice, and clinical consequences of human GHR gene mutations.
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Affiliation(s)
- John J Kopchick
- Growth Hormone Research Society, Edison Biotechnology Institute & Dept. of Biomedical Sciences, HCOM, Ohio University, Athens, OH 45701, United States.
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30
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Liu Y, Zhang Y, Jiang J, Lobie PE, Paulmurugan R, Langenheim JF, Chen WY, Zinn KR, Frank SJ. GHR/PRLR Heteromultimer Is Composed of GHR Homodimers and PRLR Homodimers. Mol Endocrinol 2016; 30:504-17. [PMID: 27003442 DOI: 10.1210/me.2015-1319] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
GH receptor (GHR) and prolactin (PRL) receptor (PRLR) are homologous transmembrane cytokine receptors. Each prehomodimerizes and ligand binding activates Janus Kinase 2 (JAK2)-signal transducer and activator of transcription (STAT) signaling pathways by inducing conformational changes within receptor homodimers. In humans, GHR is activated by GH, whereas PRLR is activated by both GH and PRL. We previously devised a split luciferase complementation assay, in which 1 receptor is fused to an N-terminal luciferase (Nluc) fragment, and the other receptor is fused to a C-terminal luciferase (Cluc) fragment. When receptors approximate, luciferase activity (complementation) results. Using this assay, we reported ligand-independent GHR-GHR complementation and GH-induced complementation changes characterized by acute augmentation above basal signal, consistent with induction of conformational changes that bring GHR cytoplasmic tails closer. We also demonstrated association between GHR and PRLR in T47D human breast cancer cells by coimmunoprecipitation, suggesting that, in addition to forming homodimers, these receptors form hetero-assemblages with functional consequences. We now extend these analyses to examine basal and ligand-induced complementation of coexpressed PRLR-Nluc and PRLR-Cluc chimeras and coexpressed GHR-Nluc and PRLR-Cluc chimeras. We find that PRLR-PRLR and GHR-PRLR form specifically interacting ligand-independent assemblages and that either GH or PRL augments PRLR-PRLR complementation, much like the GH-induced changes in GHR-GHR dimers. However, in contrast to the complementation patterns for GHR-GHR or PRLR-PRLR homomers, both GH and PRL caused decline in luciferase activity for GHR-PRLR heteromers. These and other data suggest that GHR and PRLR associate in complexes comprised of GHR-GHR/PRLR-PRLR heteromers consisting of GHR homodimers and PRLR homodimers, rather than GHR-PRLR heterodimers.
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Affiliation(s)
- Ying Liu
- Department of Medicine (Y.L., Y.Z., J.J., S.J.F.), Division of Endocrinology, Diabetes, and Metabolism; Department of Radiology (K.R.Z.); and Department of Cell, Developmental, and Integrative Biology (S.J.F.), University of Alabama at Birmingham, Birmingham, Alabama 35294; Cancer Science Institute of Singapore and Department of Pharmacology (P.E.L.), National University of Singapore, Singapore 119077; Department of Radiology (R.P.), Stanford University School of Medicine, Palo Alto, California 94304; Department of Biological Sciences (J.F.L., W.Y.C.), Clemson University, Clemson, South Carolina 29634; and Endocrinology Section (S.J.F.), Medical Service, Veterans Affairs Medical Center, Birmingham, Alabama 35233
| | - Yue Zhang
- Department of Medicine (Y.L., Y.Z., J.J., S.J.F.), Division of Endocrinology, Diabetes, and Metabolism; Department of Radiology (K.R.Z.); and Department of Cell, Developmental, and Integrative Biology (S.J.F.), University of Alabama at Birmingham, Birmingham, Alabama 35294; Cancer Science Institute of Singapore and Department of Pharmacology (P.E.L.), National University of Singapore, Singapore 119077; Department of Radiology (R.P.), Stanford University School of Medicine, Palo Alto, California 94304; Department of Biological Sciences (J.F.L., W.Y.C.), Clemson University, Clemson, South Carolina 29634; and Endocrinology Section (S.J.F.), Medical Service, Veterans Affairs Medical Center, Birmingham, Alabama 35233
| | - Jing Jiang
- Department of Medicine (Y.L., Y.Z., J.J., S.J.F.), Division of Endocrinology, Diabetes, and Metabolism; Department of Radiology (K.R.Z.); and Department of Cell, Developmental, and Integrative Biology (S.J.F.), University of Alabama at Birmingham, Birmingham, Alabama 35294; Cancer Science Institute of Singapore and Department of Pharmacology (P.E.L.), National University of Singapore, Singapore 119077; Department of Radiology (R.P.), Stanford University School of Medicine, Palo Alto, California 94304; Department of Biological Sciences (J.F.L., W.Y.C.), Clemson University, Clemson, South Carolina 29634; and Endocrinology Section (S.J.F.), Medical Service, Veterans Affairs Medical Center, Birmingham, Alabama 35233
| | - Peter E Lobie
- Department of Medicine (Y.L., Y.Z., J.J., S.J.F.), Division of Endocrinology, Diabetes, and Metabolism; Department of Radiology (K.R.Z.); and Department of Cell, Developmental, and Integrative Biology (S.J.F.), University of Alabama at Birmingham, Birmingham, Alabama 35294; Cancer Science Institute of Singapore and Department of Pharmacology (P.E.L.), National University of Singapore, Singapore 119077; Department of Radiology (R.P.), Stanford University School of Medicine, Palo Alto, California 94304; Department of Biological Sciences (J.F.L., W.Y.C.), Clemson University, Clemson, South Carolina 29634; and Endocrinology Section (S.J.F.), Medical Service, Veterans Affairs Medical Center, Birmingham, Alabama 35233
| | - Ramasamy Paulmurugan
- Department of Medicine (Y.L., Y.Z., J.J., S.J.F.), Division of Endocrinology, Diabetes, and Metabolism; Department of Radiology (K.R.Z.); and Department of Cell, Developmental, and Integrative Biology (S.J.F.), University of Alabama at Birmingham, Birmingham, Alabama 35294; Cancer Science Institute of Singapore and Department of Pharmacology (P.E.L.), National University of Singapore, Singapore 119077; Department of Radiology (R.P.), Stanford University School of Medicine, Palo Alto, California 94304; Department of Biological Sciences (J.F.L., W.Y.C.), Clemson University, Clemson, South Carolina 29634; and Endocrinology Section (S.J.F.), Medical Service, Veterans Affairs Medical Center, Birmingham, Alabama 35233
| | - John F Langenheim
- Department of Medicine (Y.L., Y.Z., J.J., S.J.F.), Division of Endocrinology, Diabetes, and Metabolism; Department of Radiology (K.R.Z.); and Department of Cell, Developmental, and Integrative Biology (S.J.F.), University of Alabama at Birmingham, Birmingham, Alabama 35294; Cancer Science Institute of Singapore and Department of Pharmacology (P.E.L.), National University of Singapore, Singapore 119077; Department of Radiology (R.P.), Stanford University School of Medicine, Palo Alto, California 94304; Department of Biological Sciences (J.F.L., W.Y.C.), Clemson University, Clemson, South Carolina 29634; and Endocrinology Section (S.J.F.), Medical Service, Veterans Affairs Medical Center, Birmingham, Alabama 35233
| | - Wen Y Chen
- Department of Medicine (Y.L., Y.Z., J.J., S.J.F.), Division of Endocrinology, Diabetes, and Metabolism; Department of Radiology (K.R.Z.); and Department of Cell, Developmental, and Integrative Biology (S.J.F.), University of Alabama at Birmingham, Birmingham, Alabama 35294; Cancer Science Institute of Singapore and Department of Pharmacology (P.E.L.), National University of Singapore, Singapore 119077; Department of Radiology (R.P.), Stanford University School of Medicine, Palo Alto, California 94304; Department of Biological Sciences (J.F.L., W.Y.C.), Clemson University, Clemson, South Carolina 29634; and Endocrinology Section (S.J.F.), Medical Service, Veterans Affairs Medical Center, Birmingham, Alabama 35233
| | - Kurt R Zinn
- Department of Medicine (Y.L., Y.Z., J.J., S.J.F.), Division of Endocrinology, Diabetes, and Metabolism; Department of Radiology (K.R.Z.); and Department of Cell, Developmental, and Integrative Biology (S.J.F.), University of Alabama at Birmingham, Birmingham, Alabama 35294; Cancer Science Institute of Singapore and Department of Pharmacology (P.E.L.), National University of Singapore, Singapore 119077; Department of Radiology (R.P.), Stanford University School of Medicine, Palo Alto, California 94304; Department of Biological Sciences (J.F.L., W.Y.C.), Clemson University, Clemson, South Carolina 29634; and Endocrinology Section (S.J.F.), Medical Service, Veterans Affairs Medical Center, Birmingham, Alabama 35233
| | - Stuart J Frank
- Department of Medicine (Y.L., Y.Z., J.J., S.J.F.), Division of Endocrinology, Diabetes, and Metabolism; Department of Radiology (K.R.Z.); and Department of Cell, Developmental, and Integrative Biology (S.J.F.), University of Alabama at Birmingham, Birmingham, Alabama 35294; Cancer Science Institute of Singapore and Department of Pharmacology (P.E.L.), National University of Singapore, Singapore 119077; Department of Radiology (R.P.), Stanford University School of Medicine, Palo Alto, California 94304; Department of Biological Sciences (J.F.L., W.Y.C.), Clemson University, Clemson, South Carolina 29634; and Endocrinology Section (S.J.F.), Medical Service, Veterans Affairs Medical Center, Birmingham, Alabama 35233
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Ramos-Leví AM, Bernabeu I, Sampedro-Núñez M, Marazuela M. Genetic Predictors of Response to Different Medical Therapies in Acromegaly. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2016; 138:85-114. [PMID: 26940388 DOI: 10.1016/bs.pmbts.2015.10.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
In the era of predictive medicine, management of diseases is evolving into a more personal and individualized approach, as more data are available regarding clinical, biochemical, radiological, molecular, histopathological, and genetic aspects. In the particular setting of acromegaly, which is a rare, chronic, debilitating, and disfiguring disease, an optimized approach deems even more necessary, especially because of an associated increased morbidity and mortality, the impact on patients' quality of life, and the increased cost of frequently necessary life-long treatments. In this paper, we review the available studies that address potential genetic influences on acromegaly, their role in the outcome, and response to treatments, as well as their contribution to the risk of developing side effects. We focus mainly on pharmacogenetic factors involved during treatment with dopamine agonists, somatostatin analogs, and pegvisomant. Specifically, mutations in dopamine receptors, somatostatin receptors, growth hormone receptors, and metabolic pathways involved in growth hormone action; polymorphisms in the insulin-like growth factor and the insulin-like growth factor binding proteins; and polymorphisms in other genes that may determine differences in the frequency of developing adverse events.
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Affiliation(s)
- Ana M Ramos-Leví
- Department of Endocrinology and Nutrition, Hospital Universitario la Princesa, Instituto de Investigación Princesa, Universidad Autónoma de Madrid, Madrid, Spain
| | - Ignacio Bernabeu
- Department of Endocrinology and Nutrition, Complejo Hospitalario Universitario de Santiago de Compostela, Servicio Gallego de Salud (SERGAS); Universidad de Santiago de Compostela, La Coruña, Spain
| | - Miguel Sampedro-Núñez
- Department of Endocrinology and Nutrition, Hospital Universitario la Princesa, Instituto de Investigación Princesa, Universidad Autónoma de Madrid, Madrid, Spain
| | - Mónica Marazuela
- Department of Endocrinology and Nutrition, Hospital Universitario la Princesa, Instituto de Investigación Princesa, Universidad Autónoma de Madrid, Madrid, Spain.
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Nespital T, van der Velden LM, Mensinga A, van der Vaart ED, Strous GJ. Fos-Zippered GH Receptor Cytosolic Tails Act as Jak2 Substrates and Signal Transducers. Mol Endocrinol 2016; 30:290-301. [PMID: 26859362 DOI: 10.1210/me.2015-1315] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Members of the Janus kinase (Jak) family initiate the majority of downstream signaling events of the cytokine receptor family. The prevailing principle is that the receptors act in dimers: 2 Jak2 molecules bind to the cytosolic tails of a cytokine receptor family member and initiate Jak-signal transducer and activator of transcription signaling upon a conformational change in the receptor complex, induced by the cognate cytokine. Due to the complexity of signaling complexes, there is a strong need for in vitro model systems. To investigate the molecular details of the Jak2 interaction with the GH receptor (GHR), we used cytosolic tails provided with leucine zippers derived from c-Fos to mimic the dimerized state of GHR. Expressed together with Jak2, fos-zippered tails, but not unzippered tails, were stabilized. In addition, the Jak-signal transducer and activator of transcription signaling pathway was activated by the fos-zippered tails. The stabilization depended also on α-helix rotation of the zippers. Fos-zippered GHR tails and Jak2, both purified from baculovirus-infected insect cells, interacted via box1 with a binding affinity of approximately 40nM. As expected, the Jak kinase inhibitor Ruxolitinib inhibited the stabilization but did not affect the c-Fos-zippered GHR tail-Jak2 interaction. Analysis by blue-native gel electrophoresis revealed high molecular-weight complexes containing both Jak2 and nonphosphorylated GHR tails, whereas Jak2-dissociated tails were highly phosphorylated and monomeric, implying that Jak2 detaches from its substrate upon phosphorylation.
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Affiliation(s)
- Tobias Nespital
- Department of Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
| | - Lieke M van der Velden
- Department of Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
| | - Anneloes Mensinga
- Department of Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
| | - Elisabeth D van der Vaart
- Department of Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
| | - Ger J Strous
- Department of Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
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Groothuizen FS, Poger D, Mark AE. Activating the Prolactin Receptor: Effect of the Ligand on the Conformation of the Extracellular Domain. J Chem Theory Comput 2015; 6:3274-83. [PMID: 26616789 DOI: 10.1021/ct1003934] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The prolactin receptor resides on the surface of the cell as a preformed dimer. This suggests that cell signaling is triggered by conformational changes within the extracellular domain of the receptors. Here, by using atomistic molecular dynamics simulations, we show that the removal of the ligand placental lactogen from the dimeric form of the prolactin receptor results in a relative reorientation of the two extracellular domains by 20-30°, which corresponds to a clockwise rotation of the domains with respect to each other. Such a mechanism of activation for the prolactin receptor is similar to that proposed previously in the case of the growth hormone receptor. In addition to the effect of the removal of the ligand, the mechanical coupling between the extracellular and transmembrane domains within a model membrane was also examined.
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Affiliation(s)
- Flora S Groothuizen
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia, and Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - David Poger
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia, and Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Alan E Mark
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia, and Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
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Kwon MJ, Park J, Jang S, Eom CY, Oh ES. The Conserved Phenylalanine in the Transmembrane Domain Enhances Heteromeric Interactions of Syndecans. J Biol Chem 2015; 291:872-81. [PMID: 26601939 DOI: 10.1074/jbc.m115.685040] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Indexed: 11/06/2022] Open
Abstract
The transmembrane domain (TMD) of the syndecans, a family of transmembrane heparin sulfate proteoglycans, is involved in forming homo- and heterodimers and oligomers that transmit signaling events. Recently, we reported that the unique phenylalanine in TMD positively regulates intramolecular interactions of syndecan-2. Besides the unique phenylalanine, syndecan-2 contains a conserved phenylalanine (SDC2-Phe-169) that is present in all syndecan TMDs, but its function has not been determined. We therefore investigated the structural role of SDC2-Phe-169 in syndecan TMDs. Replacement of SDC2-Phe-169 by tyrosine (S2F169Y) did not affect SDS-resistant homodimer formation but significantly reduced SDS-resistant heterodimer formation between syndecan-2 and -4, suggesting that SDC2-Phe-169 is involved in the heterodimerization/oligomerization of syndecans. Similarly, in an in vitro binding assay, a syndecan-2 mutant (S2(F169Y)) showed a significantly reduced interaction with syndecan-4. FRET assays showed that heteromolecular interactions between syndecan-2 and -4 were reduced in HEK293T cells transfected with S2(F169Y) compared with syndecan-2. Moreover, S2(F169Y) reduced downstream reactions mediated by the heterodimerization of syndecan-2 and -4, including Rac activity, cell migration, membrane localization of PKCα, and focal adhesion formation. The conserved phenylalanine in syndecan-1 and -3 also showed heterodimeric interaction with syndecan-2 and -4. Taken together, these findings suggest that the conserved phenylalanine in the TMD of syndecans is crucial in regulating heteromeric interactions of syndecans.
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Affiliation(s)
- Mi-Jung Kwon
- From the Department of Life Sciences, Research Center for Cellular Homeostasis, Ewha Womans University, Seoul 120-750, Korea and
| | - Jisu Park
- From the Department of Life Sciences, Research Center for Cellular Homeostasis, Ewha Womans University, Seoul 120-750, Korea and
| | - Sinae Jang
- the Seoul Center, Korea Basic Science Institute, Seoul 136-075, Korea
| | - Chi-Yong Eom
- the Seoul Center, Korea Basic Science Institute, Seoul 136-075, Korea
| | - Eok-Soo Oh
- From the Department of Life Sciences, Research Center for Cellular Homeostasis, Ewha Womans University, Seoul 120-750, Korea and
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Loyau J, Malinge P, Daubeuf B, Shang L, Elson G, Kosco-Vilbois M, Fischer N, Rousseau F. Maximizing the potency of an anti-TLR4 monoclonal antibody by exploiting proximity to Fcγ receptors. MAbs 2015; 6:1621-30. [PMID: 25484053 PMCID: PMC4622919 DOI: 10.4161/19420862.2014.975098] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
In order to treat Toll like receptor 4 (TLR4)-mediated diseases, we generated a potent antagonistic antibody directed against human TLR4, Hu 15C1. This antibody's potency can be modulated by engaging not only TLR4 but also Fcγ receptors (FcγR), a mechanism that is driven by avidity and not cell signaling. Here, using various formats of the antibody, we further dissect the relative contributions of the Fv and Fc portions of Hu 15C1, discovering that the relationship to potency of the different antibody arms is not linear. First, as could be anticipated, we observed that Hu 15C1 co-engages up to 3 receptors on the same plasma membrane, i.e., 2 TLR4 molecules (via its variable regions) and either FcγRI or FcγRIIA (via the Fc). The Kd of these interactions are in the nM range (3 nM of the Fv for TLR4 and 47 nM of the Fc for FcγRI). However, unexpectedly, neutralization experiments revealed that, due to the low level of cell surface TLR4 expression, the avidity afforded by engagement through 2 Fv arms was significantly limited. In contrast, the antibody's neutralization capacity increases by 3 logs when able to exploit Fc-FcγR interactions. Taken together, these results demonstrate an unforeseen level of contribution by FcγRs to an antibody's effectiveness when targeting a cell surface protein of relatively low abundance. These findings highlight an exploitable mechanism by which FcγR-bearing cells may be more powerfully targeted, envisioned to be broadly applicable to other reagents aimed at neutralizing cell surface targets on cells co-expressing FcγRs.
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Key Words
- DAMP, damage-associated molecular pattern
- Fc gamma receptors
- Fc, fragment crystallizable
- FcγR, Fc gamma receptor
- Fv, fragment variable
- IL, interleukin
- IVIg, intravenous immunoglobulin
- Ig, immunoglobulin
- LPS, lipopolysaccharide
- PAMP, pathogen-associated molecular pattern
- TLR, Toll-like receptor
- TLR4
- affinity maturation
- antibody
- avidity
- mAb, monoclonal antibody
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Maruyama IN. Activation of transmembrane cell-surface receptors via a common mechanism? The "rotation model". Bioessays 2015; 37:959-67. [PMID: 26241732 PMCID: PMC5054922 DOI: 10.1002/bies.201500041] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
It has long been thought that transmembrane cell-surface receptors, such as receptor tyrosine kinases and cytokine receptors, among others, are activated by ligand binding through ligand-induced dimerization of the receptors. However, there is growing evidence that prior to ligand binding, various transmembrane receptors have a preformed, yet inactive, dimeric structure on the cell surface. Various studies also demonstrate that during transmembrane signaling, ligand binding to the extracellular domain of receptor dimers induces a rotation of transmembrane domains, followed by rearrangement and/or activation of intracellular domains. The paper here describes transmembrane cell-surface receptors that are known or proposed to exist in dimeric form prior to ligand binding, and discusses how these preformed dimers are activated by ligand binding.
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Affiliation(s)
- Ichiro N Maruyama
- Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa, Japan
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37
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Leptin: From structural insights to the design of antagonists. Life Sci 2015; 140:49-56. [PMID: 25998027 DOI: 10.1016/j.lfs.2015.04.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 04/28/2015] [Accepted: 04/29/2015] [Indexed: 12/20/2022]
Abstract
After its discovery in 1994, it soon became clear that leptin acts as an adipocyte-derived hormone with a central role in the control of body weight and energy homeostasis. However, a growing body of evidence has revealed that leptin is a pleiotropic cytokine with activities on many peripheral cell types. Inappropriate leptin signaling can promote autoimmunity, certain cardiovascular diseases, elevated blood pressure and cancer, which makes leptin and the leptin receptor interesting targets for antagonism. Profound insights in the leptin receptor (LR) activation mechanisms are a prerequisite for the rational design of these antagonists. In this review, we focus on the molecular mechanisms underlying leptin receptor activation and signaling. We also discuss the current strategies to interfere with leptin signaling and their therapeutic potential.
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Lim SV, Marenzana M, Hopkinson M, List EO, Kopchick JJ, Pereira M, Javaheri B, Roux JP, Chavassieux P, Korbonits M, Chenu C. Excessive growth hormone expression in male GH transgenic mice adversely alters bone architecture and mechanical strength. Endocrinology 2015; 156:1362-71. [PMID: 25646711 PMCID: PMC4399323 DOI: 10.1210/en.2014-1572] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Patients with acromegaly have a higher prevalence of vertebral fractures despite normal bone mineral density (BMD), suggesting that GH overexpression has adverse effects on skeletal architecture and strength. We used giant bovine GH (bGH) transgenic mice to analyze the effects of high serum GH levels on BMD, architecture, and mechanical strength. Five-month-old hemizygous male bGH mice were compared with age- and sex-matched nontransgenic littermates controls (NT; n=16/group). Bone architecture and BMD were analyzed in tibia and lumbar vertebrae using microcomputed tomography. Femora were tested to failure using three-point bending and bone cellular activity determined by bone histomorphometry. bGH transgenic mice displayed significant increases in body weight and bone lengths. bGH tibia showed decreases in trabecular bone volume fraction, thickness, and number compared with NT ones, whereas trabecular pattern factor and structure model index were significantly increased, indicating deterioration in bone structure. Although cortical tissue perimeter was increased in transgenic mice, cortical thickness was reduced. bGH mice showed similar trabecular BMD but reduced trabecular thickness in lumbar vertebra relative to controls. Cortical BMD and thickness were significantly reduced in bGH lumbar vertebra. Mechanical testing of femora confirmed that bGH femora have decreased intrinsic mechanical properties compared with NT ones. Bone turnover is increased in favor of bone resorption in bGH tibia and vertebra compared with controls, and serum PTH levels is also enhanced in bGH mice. These data collectively suggest that high serum GH levels negatively affect bone architecture and quality at multiple skeletal sites.
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Affiliation(s)
- S V Lim
- Department of Comparative and Biomedical Sciences (S.V.L., M.H., M.P., B.J., C.C.), Royal Veterinary College, London NW1 0TU, United Kingdom; Imperial College (M.M.), London SW7 2AZ, United Kingdom; Edison Biotechnology Institute (E.O.L., J.J.K.), Ohio University, Ohio 45701; INSERM Unité Mixte de Recherche 1033 and Université de Lyon (J.P.R., P.C.), 69372 Lyon Cedex 08, France; and Department of Endocrinology (M.K.), Barts and the London School of Medicine, Queen Mary University of London, London EC1A 6BQ, United Kingdom
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39
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Moraga I, Wernig G, Wilmes S, Gryshkova V, Richter CP, Hong WJ, Sinha R, Guo F, Fabionar H, Wehrman TS, Krutzik P, Demharter S, Plo I, Weissman IL, Minary P, Majeti R, Constantinescu SN, Piehler J, Garcia KC. Tuning cytokine receptor signaling by re-orienting dimer geometry with surrogate ligands. Cell 2015; 160:1196-208. [PMID: 25728669 PMCID: PMC4766813 DOI: 10.1016/j.cell.2015.02.011] [Citation(s) in RCA: 120] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Revised: 01/22/2015] [Accepted: 02/03/2015] [Indexed: 01/07/2023]
Abstract
Most cell-surface receptors for cytokines and growth factors signal as dimers, but it is unclear whether remodeling receptor dimer topology is a viable strategy to "tune" signaling output. We utilized diabodies (DA) as surrogate ligands in a prototypical dimeric receptor-ligand system, the cytokine Erythropoietin (EPO) and its receptor (EpoR), to dimerize EpoR ectodomains in non-native architectures. Diabody-induced signaling amplitudes varied from full to minimal agonism, and structures of these DA/EpoR complexes differed in EpoR dimer orientation and proximity. Diabodies also elicited biased or differential activation of signaling pathways and gene expression profiles compared to EPO. Non-signaling diabodies inhibited proliferation of erythroid precursors from patients with a myeloproliferative neoplasm due to a constitutively active JAK2V617F mutation. Thus, intracellular oncogenic mutations causing ligand-independent receptor activation can be counteracted by extracellular ligands that re-orient receptors into inactive dimer topologies. This approach has broad applications for tuning signaling output for many dimeric receptor systems.
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Affiliation(s)
- Ignacio Moraga
- Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, California, 94305-5345, USA,Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, California, 94305-5345, USA
| | - Gerlinde Wernig
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California, 94305-5345, USA,Department of Pathology, Division of Hematopathology, Stanford University School of Medicine, Stanford, California, 94305-5345, USA
| | - Stephan Wilmes
- Division of Biophysics, Department of Biology, University of Osnabrück, 49076, Germany
| | - Vitalina Gryshkova
- Ludwig Institute For Cancer Research and de Duve Institute, Université catholique de Louvain, B-1200 Brussels, Belgium
| | | | - Wan-Jen Hong
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California, 94305-5345, USA,Department of Internal Medicine, Division of Hematology, Stanford University School of Medicine, Stanford, California, 94305-5345, USA
| | - Rahul Sinha
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California, 94305-5345, USA
| | - Feng Guo
- Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, California, 94305-5345, USA,Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, California, 94305-5345, USA
| | - Hyna Fabionar
- DiscoveRx, 42501 Albrae St, Fremont, California, 94538, USA
| | - Tom S. Wehrman
- Primity Bio, 3350 Scott blvd ste 6101, Santa Clara, CA 95054
| | - Peter Krutzik
- Primity Bio, 3350 Scott blvd ste 6101, Santa Clara, CA 95054
| | - Samuel Demharter
- Department of Computer Science Wolfson Building, University of Oxford, Oxford OX1 3QD, United Kingdom
| | - Isabelle Plo
- Institut Gustave Roussy, INSERM U1009, 94805, Villejuif, France
| | - Irving L. Weissman
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California, 94305-5345, USA
| | - Peter Minary
- Department of Computer Science Wolfson Building, University of Oxford, Oxford OX1 3QD, United Kingdom
| | - Ravindra Majeti
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California, 94305-5345, USA,Department of Internal Medicine, Division of Hematology, Stanford University School of Medicine, Stanford, California, 94305-5345, USA
| | - Stefan N. Constantinescu
- Ludwig Institute For Cancer Research and de Duve Institute, Université catholique de Louvain, B-1200 Brussels, Belgium
| | - Jacob Piehler
- Division of Biophysics, Department of Biology, University of Osnabrück, 49076, Germany
| | - K. Christopher Garcia
- Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, California, 94305-5345, USA,Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, California, 94305-5345, USA,Correspondence to:
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40
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The molecular basis for functional plasticity in type I interferon signaling. Trends Immunol 2015; 36:139-49. [DOI: 10.1016/j.it.2015.01.002] [Citation(s) in RCA: 136] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Revised: 01/13/2015] [Accepted: 01/13/2015] [Indexed: 01/16/2023]
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41
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The thrombopoietin receptor P106L mutation functionally separates receptor signaling activity from thrombopoietin homeostasis. Blood 2014; 125:1159-69. [PMID: 25538044 DOI: 10.1182/blood-2014-07-587170] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The interaction between thrombopoietin (THPO) and its receptor c-Mpl regulates downstream cytokine signaling and platelet homeostasis. Hereditary mutations of c-Mpl can either result in loss-of-function and thrombocytopenia or in gain-of-function and thrombocythemia (HT), and are important models to analyze the mechanism of c-Mpl activity. We have analyzed the effect of the c-Mpl P106L gain-of-function and the nearby loss-of-function R102P and F104S mutations, which cause HT or thrombocytopenia, respectively, on posttranslational processing, intracellular trafficking, cell surface expression, and cell proliferation. In contrast to R102P and F104S, the P106L mutant confers cytokine-independent growth and stimulates downstream signaling after THPO treatment in Ba/F3 cells. Despite their opposite function, R102P and P106L, both lead to abnormal subcellular receptor distribution, lack of membrane localization, impaired glycosylation, and elevated THPO serum levels in effected patients. These findings indicate that the activation of downstream signaling by c-Mpl P106L does not require correct processing, trafficking, and cell surface expression of c-Mpl, whereas the negative feedback loop controlling THPO serum levels requires cell surface expression of the receptor. Thus, we propose that the P106L mutation functionally separates the activity of c-Mpl in downstream signaling from that in maintaining platelet homeostasis.
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42
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Wang X, Yang L, Wang H, Shao F, Yu J, Jiang H, Han Y, Gong D, Gu Z. Growth hormone-regulated mRNAs and miRNAs in chicken hepatocytes. PLoS One 2014; 9:e112896. [PMID: 25386791 PMCID: PMC4227886 DOI: 10.1371/journal.pone.0112896] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Accepted: 10/16/2014] [Indexed: 12/02/2022] Open
Abstract
Growth hormone (GH) is a key regulatory factor in animal growth, development and metabolism. Based on the expression level of the GH receptor, the chicken liver is a major target organ of GH, but the biological effects of GH on the chicken liver are not fully understood. In this work we identified mRNAs and miRNAs that are regulated by GH in primary hepatocytes from female chickens through RNA-seq, and analyzed the functional relevance of these mRNAs and miRNAs through GO enrichment analysis and miRNA target prediction. A total of 164 mRNAs were found to be differentially expressed between GH-treated and control chicken hepatocytes, of which 112 were up-regulated and 52 were down-regulated by GH. A total of 225 chicken miRNAs were identified by the RNA-Seq analysis. Among these miRNAs 16 were up-regulated and 1 miRNA was down-regulated by GH. The GH-regulated mRNAs were mainly involved in growth and metabolism. Most of the GH-upregulated or GH-downregulated miRNAs were predicted to target the GH-downregulated or GH-upregulated mRNAs, respectively, involved in lipid metabolism. This study reveals that GH regulates the expression of many mRNAs involved in metabolism in female chicken hepatocytes, which suggests that GH plays an important role in regulating liver metabolism in female chickens. The results of this study also support the hypothesis that GH regulates lipid metabolism in chicken liver in part by regulating the expression of miRNAs that target the mRNAs involved in lipid metabolism.
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Affiliation(s)
- Xingguo Wang
- Department of Life Science and Technology, Changshu Institute of Technology, Changshu, P R China
- College of Animal Science and Technology, Yangzhou University, Yangzhou, P R China
| | - Lei Yang
- Department of Life Science and Technology, Changshu Institute of Technology, Changshu, P R China
| | - Huijuan Wang
- Department of Life Science and Technology, Changshu Institute of Technology, Changshu, P R China
| | - Fang Shao
- Department of Life Science and Technology, Changshu Institute of Technology, Changshu, P R China
| | - JianFeng Yu
- Department of Life Science and Technology, Changshu Institute of Technology, Changshu, P R China
| | - Honglin Jiang
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
| | - Yaoping Han
- Department of Life Science and Technology, Changshu Institute of Technology, Changshu, P R China
| | - Daoqing Gong
- College of Animal Science and Technology, Yangzhou University, Yangzhou, P R China
| | - Zhiliang Gu
- Department of Life Science and Technology, Changshu Institute of Technology, Changshu, P R China
- * E-mail:
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43
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Peelman F, Zabeau L, Moharana K, Savvides SN, Tavernier J. 20 years of leptin: insights into signaling assemblies of the leptin receptor. J Endocrinol 2014; 223:T9-23. [PMID: 25063754 DOI: 10.1530/joe-14-0264] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Leptin plays a central role in the control of body weight and energy homeostasis, but is a pleiotropic cytokine with activities on many peripheral cell types. In this review, we discuss the interaction of leptin with its receptor, and focus on the structural and mechanistic aspects of the extracellular aspects of leptin receptor (LR) activation. We provide an extensive overview of all structural information that has been obtained for leptin and its receptor via X-ray crystallography, electron microscopy, small-angle X-ray scattering, homology modeling, and mutagenesis studies. The available knowledge is integrated into putative models toward a recapitulation of the LR activation mechanism.
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Affiliation(s)
- Frank Peelman
- Department of Medical Protein ResearchFaculty of Medicine and Health Sciences, Flanders Institute for Biotechnology (VIB), Ghent University, A. Baertsoenkaai 3, 9000 Ghent, BelgiumUnit for Structural BiologyLaboratory for Protein Biochemistry and Biomolecular Engineering (L-ProBE), Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
| | - Lennart Zabeau
- Department of Medical Protein ResearchFaculty of Medicine and Health Sciences, Flanders Institute for Biotechnology (VIB), Ghent University, A. Baertsoenkaai 3, 9000 Ghent, BelgiumUnit for Structural BiologyLaboratory for Protein Biochemistry and Biomolecular Engineering (L-ProBE), Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
| | - Kedar Moharana
- Department of Medical Protein ResearchFaculty of Medicine and Health Sciences, Flanders Institute for Biotechnology (VIB), Ghent University, A. Baertsoenkaai 3, 9000 Ghent, BelgiumUnit for Structural BiologyLaboratory for Protein Biochemistry and Biomolecular Engineering (L-ProBE), Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
| | - Savvas N Savvides
- Department of Medical Protein ResearchFaculty of Medicine and Health Sciences, Flanders Institute for Biotechnology (VIB), Ghent University, A. Baertsoenkaai 3, 9000 Ghent, BelgiumUnit for Structural BiologyLaboratory for Protein Biochemistry and Biomolecular Engineering (L-ProBE), Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
| | - Jan Tavernier
- Department of Medical Protein ResearchFaculty of Medicine and Health Sciences, Flanders Institute for Biotechnology (VIB), Ghent University, A. Baertsoenkaai 3, 9000 Ghent, BelgiumUnit for Structural BiologyLaboratory for Protein Biochemistry and Biomolecular Engineering (L-ProBE), Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
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44
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Gan Y, Buckels A, Liu Y, Zhang Y, Paterson AJ, Jiang J, Zinn KR, Frank SJ. Human GH receptor-IGF-1 receptor interaction: implications for GH signaling. Mol Endocrinol 2014; 28:1841-54. [PMID: 25211187 DOI: 10.1210/me.2014-1174] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
GH signaling yields multiple anabolic and metabolic effects. GH binds the transmembrane GH receptor (GHR) to activate the intracellular GHR-associated tyrosine kinase, Janus kinase 2 (JAK2), and downstream signals, including signal transducer and activator of transcription 5 (STAT5) activation and IGF-1 gene expression. Some GH effects are partly mediated by GH-induced IGF-1 via IGF-1 receptor (IGF-1R), a tyrosine kinase receptor. We previously demonstrated in non-human cells that GH causes formation of a GHR-JAK2-IGF-1R complex and that presence of IGF-1R (even without IGF-1 binding) augments proximal GH signaling. In this study, we use human LNCaP prostate cancer cells as a model system to further study the IGF-1R's role in GH signaling. GH promoted JAK2 and GHR tyrosine phosphorylation and STAT5 activation in LNCaP cells. By coimmunoprecipitation and a new split luciferase complementation assay, we find that GH augments GHR/IGF-1R complex formation, which is inhibited by a Fab of an antagonistic anti-GHR monoclonal antibody. Short hairpin RNA-mediated IGF-1R silencing in LNCaP cells reduced GH-induced GHR, JAK2, and STAT5 phosphorylation. Similarly, a soluble IGF-1R extracellular domain fragment (sol IGF-1R) interacts with GHR in response to GH and blunts GH signaling. Sol IGF-1R also markedly inhibits GH-induced IGF-1 gene expression in both LNCaP cells and mouse primary osteoblast cells. On the basis of these and other findings, we propose a model in which IGF-1R augments GH signaling by allowing a putative IGF-1R-associated molecule that regulates GH signaling to access the activated GHR/JAK2 complex and envision sol IGF-1R as a dominant-negative inhibitor of this IGF-1R-mediated augmentation. Physiological implications of this new model are discussed.
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Affiliation(s)
- Yujun Gan
- Department of Medicine (Y.G., A.B., Y.L., Y.Z., A.J.P., J.J., S.J.F.), Division of Endocrinology, Diabetes, and Metabolism, and Departments of Radiology (K.R.Z.) and Cell, Developmental, and Integrative Biology (S.J.F.), University of Alabama at Birmingham, Birmingham, Alabama 35294; and Endocrinology Section (S.J.F.), Medical Service, Veterans Affairs Medical Center, Birmingham, Alabama 35233
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45
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Liu Y, Berry PA, Zhang Y, Jiang J, Lobie PE, Paulmurugan R, Langenheim JF, Chen WY, Zinn KR, Frank SJ. Dynamic analysis of GH receptor conformational changes by split luciferase complementation. Mol Endocrinol 2014; 28:1807-19. [PMID: 25188449 DOI: 10.1210/me.2014-1153] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The transmembrane GH receptor (GHR) exists at least in part as a preformed homodimer on the cell surface. Structural and biochemical studies suggest that GH binds GHR in a 1:2 stoichiometry to effect acute GHR conformational changes that trigger the activation of the receptor-associated tyrosine kinase, Janus kinase 2 (JAK2), and downstream signaling. Despite information about GHR-GHR association derived from elegant fluorescence resonance energy transfer/bioluminescence resonance energy transfer studies, an assessment of the dynamics of GH-induced GHR conformational changes has been lacking. To this end, we used a split luciferase complementation assay that allowed detection in living cells of specific ligand-independent GHR-GHR interaction. Furthermore, GH treatment acutely augmented complementation of enzyme activity between GHRs fused, respectively, to N- and C-terminal fragments of firefly luciferase. Analysis of the temporal pattern of GH-induced complementation changes, pharmacological manipulation, genetic alteration of JAK2 levels, and truncation of the GHR intracellular domain (ICD) tail suggested that GH acutely enhances proximity of the GHR homodimer partners independent of the presence of JAK2, phosphorylation of GHR-luciferase chimeras, or an intact ICD. However, subsequent reduction of complementation requires JAK2 kinase activity and the ICD tail. This conclusion is in contrast to existing models of the GHR activation process.
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Affiliation(s)
- Ying Liu
- Department of Medicine (Y.L., P.A.B., Y.Z., J.J., S.J.F.), Division of Endocrinology, Diabetes, and Metabolism, and Departments of Radiology (K.R.Z.), and Cell, Developmental, and Integrative Biology (S.J.F.), University of Alabama at Birmingham, Birmingham, Alabama 35294; Cancer Science Institute of Singapore and Department of Pharmacology (P.E.L.), National University of Singapore, Singapore 119077; Department of Radiology (R.P.), Stanford University School of Medicine, Palo Alto, California 94304; Department of Biological Sciences (J.F.L., W.Y.C.), Clemson University, Clemson, South Carolina 29634; and Endocrinology Section (S.J.F.), Medical Service, Veterans Affairs Medical Center, Birmingham, Alabama 35233
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Waters MJ, Brooks AJ, Chhabra Y. A new mechanism for growth hormone receptor activation of JAK2, and implications for related cytokine receptors. JAKSTAT 2014; 3:e29569. [PMID: 25101218 PMCID: PMC4119067 DOI: 10.4161/jkst.29569] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Revised: 06/11/2014] [Accepted: 06/12/2014] [Indexed: 11/25/2022] Open
Abstract
The growth hormone receptor was the first cytokine receptor to be cloned and crystallized, and provides a valuable exemplar for activation of its cognate kinase, JAK2. We review progress in understanding its activation mechanism, in particular the molecular movements made by this constitutively dimerized receptor in response to ligand binding, and how these lead to a separation of JAK-binding Box1 motifs. Such a separation leads to removal of the pseudokinase inhibitory domain from the kinase domain of a partner JAK2 bound to the receptor, and vice versa, leading to apposition of the kinase domains and transactivation. This may be a general mechanism for class I cytokine receptor action.
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Affiliation(s)
- Michael J Waters
- Institute for Molecular Bioscience; The University of Queensland; St. Lucia, QLD Australia
| | - Andrew J Brooks
- Institute for Molecular Bioscience; The University of Queensland; St. Lucia, QLD Australia
| | - Yash Chhabra
- Institute for Molecular Bioscience; The University of Queensland; St. Lucia, QLD Australia
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Brooks AJ, Dai W, O'Mara ML, Abankwa D, Chhabra Y, Pelekanos RA, Gardon O, Tunny KA, Blucher KM, Morton CJ, Parker MW, Sierecki E, Gambin Y, Gomez GA, Alexandrov K, Wilson IA, Doxastakis M, Mark AE, Waters MJ. Mechanism of activation of protein kinase JAK2 by the growth hormone receptor. Science 2014; 344:1249783. [PMID: 24833397 DOI: 10.1126/science.1249783] [Citation(s) in RCA: 280] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Signaling from JAK (Janus kinase) protein kinases to STAT (signal transducers and activators of transcription) transcription factors is key to many aspects of biology and medicine, yet the mechanism by which cytokine receptors initiate signaling is enigmatic. We present a complete mechanistic model for activation of receptor-bound JAK2, based on an archetypal cytokine receptor, the growth hormone receptor. For this, we used fluorescence resonance energy transfer to monitor positioning of the JAK2 binding motif in the receptor dimer, substitution of the receptor extracellular domains with Jun zippers to control the position of its transmembrane (TM) helices, atomistic modeling of TM helix movements, and docking of the crystal structures of the JAK2 kinase and its inhibitory pseudokinase domain with an opposing kinase-pseudokinase domain pair. Activation of the receptor dimer induced a separation of its JAK2 binding motifs, driven by a ligand-induced transition from a parallel TM helix pair to a left-handed crossover arrangement. This separation leads to removal of the pseudokinase domain from the kinase domain of the partner JAK2 and pairing of the two kinase domains, facilitating trans-activation. This model may well generalize to other class I cytokine receptors.
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Affiliation(s)
- Andrew J Brooks
- The University of Queensland, Institute for Molecular Bioscience (IMB), St Lucia, Queensland 4072, Australia.
| | - Wei Dai
- Department of Chemical and Biomolecular Engineering, University of Houston, Houston, TX 77004, USA
| | - Megan L O'Mara
- The University of Queensland, School of Chemistry and Molecular Biosciences, St Lucia, Queensland 4072, Australia
| | - Daniel Abankwa
- The University of Queensland, Institute for Molecular Bioscience (IMB), St Lucia, Queensland 4072, Australia
| | - Yash Chhabra
- The University of Queensland, Institute for Molecular Bioscience (IMB), St Lucia, Queensland 4072, Australia
| | - Rebecca A Pelekanos
- The University of Queensland, Institute for Molecular Bioscience (IMB), St Lucia, Queensland 4072, Australia
| | - Olivier Gardon
- The University of Queensland, Institute for Molecular Bioscience (IMB), St Lucia, Queensland 4072, Australia
| | - Kathryn A Tunny
- The University of Queensland, Institute for Molecular Bioscience (IMB), St Lucia, Queensland 4072, Australia
| | - Kristopher M Blucher
- The University of Queensland, Institute for Molecular Bioscience (IMB), St Lucia, Queensland 4072, Australia
| | - Craig J Morton
- Biota Structural Biology Laboratory and Australian Cancer Research Foundation (ACRF) Rational Drug Discovery Centre, St Vincent's Institute of Medical Research, Fitzroy, Victoria 3065, Australia
| | - Michael W Parker
- Biota Structural Biology Laboratory and Australian Cancer Research Foundation (ACRF) Rational Drug Discovery Centre, St Vincent's Institute of Medical Research, Fitzroy, Victoria 3065, Australia. Department of Biochemistry and Molecular Biology and Bio21 Institute, University of Melbourne, Parkville, Victoria 3052, Australia
| | - Emma Sierecki
- The University of Queensland, Institute for Molecular Bioscience (IMB), St Lucia, Queensland 4072, Australia
| | - Yann Gambin
- The University of Queensland, Institute for Molecular Bioscience (IMB), St Lucia, Queensland 4072, Australia
| | - Guillermo A Gomez
- The University of Queensland, Institute for Molecular Bioscience (IMB), St Lucia, Queensland 4072, Australia
| | - Kirill Alexandrov
- The University of Queensland, Institute for Molecular Bioscience (IMB), St Lucia, Queensland 4072, Australia
| | - Ian A Wilson
- Scripps Research Institute, La Jolla, CA 92037, USA
| | - Manolis Doxastakis
- Department of Chemical and Biomolecular Engineering, University of Houston, Houston, TX 77004, USA
| | - Alan E Mark
- The University of Queensland, Institute for Molecular Bioscience (IMB), St Lucia, Queensland 4072, Australia. The University of Queensland, School of Chemistry and Molecular Biosciences, St Lucia, Queensland 4072, Australia
| | - Michael J Waters
- The University of Queensland, Institute for Molecular Bioscience (IMB), St Lucia, Queensland 4072, Australia.
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Affiliation(s)
- James A Wells
- Pharmaceutical Chemistry; Cellular and Molecular Pharmacology, University of California, San Francisco, 1700 4th Street, San Francisco, CA 94158, USA.
| | - Anthony A Kossiakoff
- Biochemistry and Molecular Biology, University of Chicago, Chicago, IL 60637, USA.
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Moharana K, Zabeau L, Peelman F, Ringler P, Stahlberg H, Tavernier J, Savvides S. Structural and Mechanistic Paradigm of Leptin Receptor Activation Revealed by Complexes with Wild-Type and Antagonist Leptins. Structure 2014; 22:866-77. [DOI: 10.1016/j.str.2014.04.012] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Revised: 04/17/2014] [Accepted: 04/24/2014] [Indexed: 12/18/2022]
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Sedek M, van der Velden LM, Strous GJ. Multimeric growth hormone receptor complexes serve as signaling platforms. J Biol Chem 2013; 289:65-73. [PMID: 24280222 DOI: 10.1074/jbc.m113.523373] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Growth hormone (GH) signaling is required for promoting longitudinal body growth, stem cell activation, differentiation, and survival and for regulation of metabolism. Failure to adequately regulate GH signaling leads to disease: excessive GH signaling has been connected to cancer, and GH insensitivity has been reported in cachexia patients. Since its discovery in 1989, the receptor has served a pivotal role as the prototype cytokine receptor both structurally and functionally. Phosphorylation and ubiquitylation regulate the GH receptor (GHR) at the cell surface: two ubiquitin ligases (SCF(βTrCP2) and CHIP) determine the GH responsiveness of cells by controlling its endocytosis, whereas JAK2 initiates the JAK/STAT pathway. We used blue native electrophoresis to identify phosphorylated and ubiquitylated receptor intermediates. We show that GHRs occur as ∼500-kDa complexes that dimerize into active ∼900-kDa complexes upon GH binding. The dimerized complexes act as platforms for transient interaction with JAK2 and ubiquitin ligases. If GH and receptors are made in the same cell (autocrine mode), only limited numbers of ∼900-kDa complexes are formed. The experiments reveal the dynamic changes in post-translational modifications during GH-induced signaling events and show that relatively simple cytokine receptors like GHRs are able to form higher order protein complexes. Insight in the complex formation of cytokine receptors is crucially important for engineering cytokines that control ligand-induced cell responses and for generating a new class of therapeutic agents for a wide range of diseases.
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Affiliation(s)
- Magdalena Sedek
- From the Department of Cell Biology and Institute of Biomembranes, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands
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