1
|
Kameda H, Yamamoto M, Tone Y, Tone M, Melmed S. Proton Sensitivity of Corticotropin-Releasing Hormone Receptor 1 Signaling to Proopiomelanocortin in Male Mice. Endocrinology 2019; 160:276-291. [PMID: 30535142 PMCID: PMC6324021 DOI: 10.1210/en.2018-00920] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2018] [Accepted: 12/03/2018] [Indexed: 12/20/2022]
Abstract
Because an acidic cellular microenvironment is engendered by inflammation and may determine cell differentiation, we elucidated the impact of acidic conditions on induction of proopiomelanocortin (POMC) expression. Here, we demonstrate mechanisms for proton sensitivity of CRH receptor 1 (CRHR1) signaling to POMC and ACTH production. Low pH (6.8) resulted in doubling of POMC expression and ACTH production in pituitary cell line AtT-20 and in primary mouse pituitary cells. Using CRISPR knockout, we show that CRHR1 is necessary for acid-induced POMC expression, and this induction is mediated by CRHR1 histidine residues and calmodulin-dependent protein kinase II in both pituitary corticotroph cells and in nonpituitary cell lines expressing ectopic ACTH. In contrast, CRH ligand binding affinity to CRHR1 was decreased with acidic pH, implying that proton-induced POMC expression prevails in acidic conditions independently of CRH ligand binding. The results indicate that proton-induced CRHR1 signaling regulates ACTH production in response to an acidic microenvironment.
Collapse
Affiliation(s)
- Hiraku Kameda
- Pituitary Center, Cedars-Sinai Medical Center, Los Angeles, California
| | - Masaaki Yamamoto
- Pituitary Center, Cedars-Sinai Medical Center, Los Angeles, California
| | - Yukiko Tone
- Research Division of Immunology, Pacific Heart Lung and Blood Institute, Los Angeles, California
| | - Masahide Tone
- Research Division of Immunology, Pacific Heart Lung and Blood Institute, Los Angeles, California
| | - Shlomo Melmed
- Pituitary Center, Cedars-Sinai Medical Center, Los Angeles, California
- Correspondence: Shlomo Melmed, MD, Room 2015, Cedars-Sinai Medical Center, 8700 Beverly Boulevard, Los Angeles, California 90048. E-mail:
| |
Collapse
|
2
|
Karageorgos V, Venihaki M, Sakellaris S, Pardalos M, Kontakis G, Matsoukas MT, Gravanis A, Margioris A, Liapakis G. Current understanding of the structure and function of family B GPCRs to design novel drugs. Hormones (Athens) 2018; 17:45-59. [PMID: 29858864 DOI: 10.1007/s42000-018-0009-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 01/25/2018] [Indexed: 01/10/2023]
Abstract
Family B of G-protein-coupled receptors (GPCRs) and their ligands play a central role in a number of homeostatic mechanisms in the endocrine, gastrointestinal, skeletal, immune, cardiovascular and central nervous systems. Alterations in family B GPCR-regulated homeostatic mechanisms may cause a variety of potentially life-threatening conditions, signifying the necessity to develop novel ligands targeting these receptors. Obtaining structural and functional information on family B GPCRs will accelerate the development of novel drugs to target these receptors. Family B GPCRs are proteins that span the plasma membrane seven times, thus forming seven transmembrane domains (TM1-TM7) which are connected to each other by three extracellular (EL) and three intracellular (IL) loops. In addition, these receptors have a long extracellular N-domain and an intracellular C-tail. The upper parts of the TMs and ELs form the J-domain of receptors. The C-terminal region of peptides first binds to the N-domain of receptors. This 'first-step' interaction orients the N-terminal region of peptides towards the J-domain of receptors, thus resulting in a 'second-step' of ligand-receptor interaction that activates the receptor. Activation-associated structural changes of receptors are transmitted through TMs to their intracellular regions and are responsible for their interaction with the G proteins and activation of the latter, thus resulting in a biological effect. This review summarizes the current information regarding the structure and function of family B GPCRs and their physiological and pathophysiological roles.
Collapse
Affiliation(s)
- Vlasios Karageorgos
- Department of Pharmacology, School of Medicine, University of Crete, Voutes, 71003, Heraklion, Crete, Greece
| | - Maria Venihaki
- Department of Clinical Chemistry, School of Medicine, University of Crete, Heraklion, Crete, Greece
| | - Stelios Sakellaris
- Department of Pharmacology, School of Medicine, University of Crete, Voutes, 71003, Heraklion, Crete, Greece
| | - Michail Pardalos
- Department of Pharmacology, School of Medicine, University of Crete, Voutes, 71003, Heraklion, Crete, Greece
| | - George Kontakis
- Department of Orthopedics, University Hospital of Heraklion, Crete, Greece
| | | | - Achille Gravanis
- Department of Pharmacology, School of Medicine, University of Crete, Voutes, 71003, Heraklion, Crete, Greece
| | - Andreas Margioris
- Department of Clinical Chemistry, School of Medicine, University of Crete, Heraklion, Crete, Greece
| | - George Liapakis
- Department of Pharmacology, School of Medicine, University of Crete, Voutes, 71003, Heraklion, Crete, Greece.
| |
Collapse
|
3
|
Extending the Structural View of Class B GPCRs. Trends Biochem Sci 2017; 42:946-960. [PMID: 29132948 DOI: 10.1016/j.tibs.2017.10.003] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2017] [Revised: 10/02/2017] [Accepted: 10/09/2017] [Indexed: 01/27/2023]
Abstract
The secretin-like class B family of G protein-coupled receptors (GPCRs) are key players in hormonal homeostasis. Recent structures of various receptors in complex with a variety of orthosteric and allosteric ligands provide fundamental new insights into the function and mechanism of class B GPCRs, including: (i) ligand-induced changes in the relative orientation of the extracellular and transmembrane receptor domains; (ii) intramolecular interaction networks that stabilize conformational changes to accommodate intracellular G protein binding; and (iii) allosteric modulation of receptor activation. This review provides a comprehensive analysis of the structural, biochemical, and pharmacological data on class B GPCRs for understanding ligand-receptor interaction and modulation mechanisms and assessing the potential implications for drug discovery for the secretin-like GPCR family.
Collapse
|
4
|
Culhane KJ, Liu Y, Cai Y, Yan ECY. Transmembrane signal transduction by peptide hormones via family B G protein-coupled receptors. Front Pharmacol 2015; 6:264. [PMID: 26594176 PMCID: PMC4633518 DOI: 10.3389/fphar.2015.00264] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 10/23/2015] [Indexed: 01/28/2023] Open
Abstract
Although family B G protein-coupled receptors (GPCRs) contain only 15 members, they play key roles in transmembrane signal transduction of hormones. Family B GPCRs are drug targets for developing therapeutics for diseases ranging from metabolic to neurological disorders. Despite their importance, the molecular mechanism of activation of family B GPCRs remains largely unexplored due to the challenges in expression and purification of functional receptors to the quantity for biophysical characterization. Currently, there is no crystal structure available of a full-length family B GPCR. However, structures of key domains, including the extracellular ligand binding regions and seven-helical transmembrane regions, have been solved by X-ray crystallography and NMR, providing insights into the mechanisms of ligand recognition and selectivity, and helical arrangements within the cell membrane. Moreover, biophysical and biochemical methods have been used to explore functions, key residues for signaling, and the kinetics and dynamics of signaling processes. This review summarizes the current knowledge of the signal transduction mechanism of family B GPCRs at the molecular level and comments on the challenges and outlook for mechanistic studies of family B GPCRs.
Collapse
Affiliation(s)
- Kelly J Culhane
- Department of Molecular Biophysics and Biochemistry, Yale University New Haven, CT, USA
| | - Yuting Liu
- Department of Chemistry, Yale University New Haven, CT, USA
| | - Yingying Cai
- Department of Chemistry, Yale University New Haven, CT, USA
| | - Elsa C Y Yan
- Department of Chemistry, Yale University New Haven, CT, USA
| |
Collapse
|
5
|
Conformational states of the full-length glucagon receptor. Nat Commun 2015; 6:7859. [PMID: 26227798 PMCID: PMC4532856 DOI: 10.1038/ncomms8859] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Accepted: 06/18/2015] [Indexed: 01/06/2023] Open
Abstract
Class B G protein-coupled receptors are composed of an extracellular domain (ECD) and a seven-transmembrane (7TM) domain, and their signalling is regulated by peptide hormones. Using a hybrid structural biology approach together with the ECD and 7TM domain crystal structures of the glucagon receptor (GCGR), we examine the relationship between full-length receptor conformation and peptide ligand binding. Molecular dynamics (MD) and disulfide crosslinking studies suggest that apo-GCGR can adopt both an open and closed conformation associated with extensive contacts between the ECD and 7TM domain. The electron microscopy (EM) map of the full-length GCGR shows how a monoclonal antibody stabilizes the ECD and 7TM domain in an elongated conformation. Hydrogen/deuterium exchange (HDX) studies and MD simulations indicate that an open conformation is also stabilized by peptide ligand binding. The combined studies reveal the open/closed states of GCGR and suggest that glucagon binds to GCGR by a conformational selection mechanism.
Collapse
|
6
|
Hollenstein K, de Graaf C, Bortolato A, Wang MW, Marshall FH, Stevens RC. Insights into the structure of class B GPCRs. Trends Pharmacol Sci 2013; 35:12-22. [PMID: 24359917 DOI: 10.1016/j.tips.2013.11.001] [Citation(s) in RCA: 161] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Revised: 10/30/2013] [Accepted: 11/01/2013] [Indexed: 02/08/2023]
Abstract
The secretin-like (class B) family of G protein-coupled receptors (GPCRs) are key players in hormonal homeostasis and are interesting drug targets for the treatment of several metabolic disorders (such as type 2 diabetes, osteoporosis, and obesity) and nervous system diseases (such as migraine, anxiety, and depression). The recently solved crystal structures of the transmembrane domains of the human glucagon receptor and human corticotropin-releasing factor receptor 1 have opened up new opportunities to study the structure and function of class B GPCRs. The current review shows how these structures offer more detailed explanations to previous biochemical and pharmacological studies of class B GPCRs, and provides new insights into their interactions with ligands.
Collapse
Affiliation(s)
- Kaspar Hollenstein
- Heptares Therapeutics Ltd, BioPark, Broadwater Road, Welwyn Garden City, AL7 3AX, UK
| | - Chris de Graaf
- Division of Medicinal Chemistry, Faculty of Sciences, Amsterdam Institute for Molecules, Medicines and Systems (AIMMS), VU University Amsterdam, De Boelelaan 1083, 1081 HV Amsterdam, The Netherlands
| | - Andrea Bortolato
- Heptares Therapeutics Ltd, BioPark, Broadwater Road, Welwyn Garden City, AL7 3AX, UK
| | - Ming-Wei Wang
- The National Center for Drug Screening and the CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences (CAS), 189 Guo Shou Jing Road, Shanghai, 201203, China
| | - Fiona H Marshall
- Heptares Therapeutics Ltd, BioPark, Broadwater Road, Welwyn Garden City, AL7 3AX, UK.
| | - Raymond C Stevens
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
| |
Collapse
|
7
|
Coin I, Katritch V, Sun T, Xiang Z, Siu FY, Beyermann M, Stevens RC, Wang L. Genetically encoded chemical probes in cells reveal the binding path of urocortin-I to CRF class B GPCR. Cell 2013; 155:1258-69. [PMID: 24290358 DOI: 10.1016/j.cell.2013.11.008] [Citation(s) in RCA: 139] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Revised: 08/26/2013] [Accepted: 11/07/2013] [Indexed: 01/19/2023]
Abstract
Molecular determinants regulating the activation of class B G-protein-coupled receptors (GPCRs) by native peptide agonists are largely unknown. We have investigated here the interaction between the corticotropin releasing factor receptor type 1 (CRF1R) and its native 40-mer peptide ligand Urocortin-I directly in mammalian cells. By incorporating unnatural amino acid photochemical and new click-chemical probes into the intact receptor expressed in the native membrane of live cells, 44 intermolecular spatial constraints have been derived for the ligand-receptor interaction. The data were analyzed in the context of the recently resolved crystal structure of CRF1R transmembrane domain and existing extracellular domain structures, yielding a complete conformational model for the peptide-receptor complex. Structural features of the receptor-ligand complex yield molecular insights on the mechanism of receptor activation and the basis for discrimination between agonist and antagonist function.
Collapse
Affiliation(s)
- Irene Coin
- Jack H. Skirball Center for Chemical Biology and Proteomics, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | | | | | | | | | | | | | | |
Collapse
|
8
|
Barwell J, Gingell JJ, Watkins HA, Archbold JK, Poyner DR, Hay DL. Calcitonin and calcitonin receptor-like receptors: common themes with family B GPCRs? Br J Pharmacol 2012; 166:51-65. [PMID: 21649645 DOI: 10.1111/j.1476-5381.2011.01525.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The calcitonin receptor (CTR) and calcitonin receptor-like receptor (CLR) are two of the 15 human family B (or Secretin-like) GPCRs. CTR and CLR are of considerable biological interest as their pharmacology is moulded by interactions with receptor activity-modifying proteins. They also have therapeutic relevance for many conditions, such as osteoporosis, diabetes, obesity, lymphatic insufficiency, migraine and cardiovascular disease. In light of recent advances in understanding ligand docking and receptor activation in both the family as a whole and in CLR and CTR specifically, this review reflects how applicable general family B GPCR themes are to these two idiosyncratic receptors. We review the main functional domains of the receptors; the N-terminal extracellular domain, the juxtamembrane domain and ligand interface, the transmembrane domain and the intracellular C-terminal domain. Structural and functional findings from the CLR and CTR along with other family B GPCRs are critically appraised to gain insight into how these domains may function. The ability for CTR and CLR to interact with receptor activity-modifying proteins adds another level of sophistication to these receptor systems but means careful consideration is needed when trying to apply generic GPCR principles. This review encapsulates current thinking in the realm of family B GPCR research by highlighting both conflicting and recurring themes and how such findings relate to two unusual but important receptors, CTR and CLR.
Collapse
Affiliation(s)
- James Barwell
- School of Life and Health Sciences, Aston University, Aston Triangle, Birmingham, UK
| | | | | | | | | | | |
Collapse
|
9
|
Coin I, Perrin MH, Vale WW, Wang L. Photo-cross-linkers incorporated into G-protein-coupled receptors in mammalian cells: a ligand comparison. Angew Chem Int Ed Engl 2011; 50:8077-81. [PMID: 21751313 DOI: 10.1002/anie.201102646] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2011] [Indexed: 01/07/2023]
Abstract
Capturing the right ligand at the right spot: a well-balanced system for non-natural amino acid mutagenesis allows the ligand binding sites of a class II G-protein coupled receptor to be mapped and distinct binding domains to be identified for different ligands in the native environment of mammalian cells.
Collapse
Affiliation(s)
- Irene Coin
- Jack H. Skirball Center for Chemical Biology and Proteomics, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | | | | | | |
Collapse
|
10
|
Coin I, Perrin MH, Vale WW, Wang L. Photo-Cross-Linkers Incorporated into G-Protein-Coupled Receptors in Mammalian Cells: A Ligand Comparison. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201102646] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
11
|
Gkountelias K, Papadokostaki M, Javitch JA, Liapakis G. Exploring the binding site crevice of a family B G protein-coupled receptor, the type 1 corticotropin releasing factor receptor. Mol Pharmacol 2010; 78:785-93. [PMID: 20664003 DOI: 10.1124/mol.110.065474] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Family B of G protein-coupled receptors (GPCRs) is composed of receptors that bind peptides, such as secretin, glucagon, parathyroid hormone, and corticotropin releasing factor (CRF), which play critical physiological roles. These receptors, like all GPCRs, share a common structural motif of seven membrane-spanning segments, which have been proposed to bind small ligands, such as antalarmin, a nonpeptide antagonist of the type 1 receptor for CRF (CRF(1)). This leads to the hypothesis that as for family A GPCRs, the binding sites of small ligands for family B GPCRs are on the surface of a water-accessible crevice, the binding-site crevice, which is formed by the membrane-spanning segments and extends from the extracellular surface of the receptor into the plane of the membrane. To test this hypothesis we have begun to obtain structural information about family B GPCRs, using as a prototype the CRF(1), by determining the ability of sulfhydryl-specific methanethiosulfonate derivatives, such as the methanethiosulfonate-ethylammonium (MTSEA), to react with CRF(1) and thus irreversibly inhibit (125)I-Tyr(0)-sauvagine binding. We found that MTSEA inhibited (125)I-Tyr(0)-sauvagine binding to CRF(1) and that antalarmin protected against this irreversible inhibition. To identify the susceptible cysteine(s), we mutated, one at a time, four endogenous cysteines to serine. Mutation to serine of Cys211, Cys233, or Cys364 decreased the susceptibility of sauvagine binding to irreversible inhibition by MTSEA. Thus, Cys211, Cys233, and Cys364 at the cytoplasmic ends of the third, fourth, and seventh membrane-spanning segments, respectively, are exposed in the binding site crevice of CRF(1).
Collapse
Affiliation(s)
- Kostas Gkountelias
- Department of Pharmacology, Faculty of Medicine, University of Crete, Heraklion 71003, Crete, Greece
| | | | | | | |
Collapse
|
12
|
D'Aoust JP, Tiberi M. Role of the extracellular amino terminus and first membrane-spanning helix of dopamine D1 and D5 receptors in shaping ligand selectivity and efficacy. Cell Signal 2010; 22:106-16. [DOI: 10.1016/j.cellsig.2009.09.020] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2009] [Accepted: 09/14/2009] [Indexed: 01/28/2023]
|