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Singh KD, Karnik SS. Implications of β-Arrestin biased signaling by angiotensin II type 1 receptor for cardiovascular drug discovery and therapeutics. Cell Signal 2024; 124:111410. [PMID: 39270918 DOI: 10.1016/j.cellsig.2024.111410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2024] [Revised: 09/06/2024] [Accepted: 09/10/2024] [Indexed: 09/15/2024]
Abstract
Angiotensin II receptors, Type 1 (AT1R) and Type 2 (AT2R) are 7TM receptors that play critical roles in both the physiological and pathophysiological regulation of the cardiovascular system. While AT1R blockers (ARBs) have proven beneficial in managing cardiac, vascular and renal maladies they cannot completely halt and reverse the progression of pathologies. Numerous experimental and animal studies have demonstrated that β-arrestin biased AT1R-ligands (such as SII-AngII, S1I8, TRV023, and TRV027) offer cardiovascular benefits by blocking the G protein signaling while retaining the β-arrestin signaling. However, these ligands failed to show improvement in heart-failure outcome over the placebo in a phase IIb clinical trial. One major limitation of current β-arrestin biased AT1R-ligands is that they are peptides with short half-lives, limiting their long-term efficacy in patients. Additionally, β-arrestin biased AT1R-ligand peptides, may inadvertently block AT2R, a promiscuous receptor, potentially negating its beneficial effects in post-myocardial infarction (MI) patients. Therefore, developing a small molecule β-arrestin biased AT1R-ligand with a longer half-life and specificity to AT1R could be more effective in treating heart failure. This approach has the potential to revolutionize the treatment of cardiovascular diseases by offering more sustained and targeted therapeutic effects.
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Affiliation(s)
- Khuraijam Dhanachandra Singh
- Department of Cardiovascular and Metabolic Sciences, Cleveland Clinic Lerner College of Medicine at Case Western Reserve University, Cleveland Clinic, USA.
| | - Sadashiva S Karnik
- Department of Cardiovascular and Metabolic Sciences, Cleveland Clinic Lerner College of Medicine at Case Western Reserve University, Cleveland Clinic, USA.
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2
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Farhadi A, Liu Y, Xu C, Wang X, Li E. The role of the renin-angiotensin system (RAS) in salinity adaptation in Pacific white shrimp ( Litopenaeus vannamei). Front Endocrinol (Lausanne) 2022; 13:1089419. [PMID: 36589833 PMCID: PMC9798321 DOI: 10.3389/fendo.2022.1089419] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 11/30/2022] [Indexed: 12/23/2022] Open
Abstract
The renin-angiotensin system (RAS) is a hormonal system that plays an important role in the regulation of blood pressure and cardiovascular homeostasis in mammals. In fishes, the RAS pathway participates in osmoregulation and salinity adaptation. However, the role of the RAS pathway in invertebrates, particularly in crustaceans, remains unknown. In this study, four key genes of the RAS pathway (LV-ACE, LV-APN, LV-AT1R, and LV-RR) were cloned, characterized, and their expression levels were detected in the eyestalk, hepatopancreas, and muscle of Litopenaeus vannamei during long-term and short-term low salinity stress. The results showed that LV-ACE, LV-APN, LV-AT1R, and LV-RR encode 666, 936, 175, and 323 amino acids, respectively. Low salinity stress downregulated the expression levels of LV-ACE, LV-APN, LV-AT1R, and LV-RR in L. vannamei, indicating that the RAS pathway was suppressed under low salinity. Moreover, these genes play important roles in the regulation of drinking rate, controlling urine output, blood glucose, and blood pressure, indicating that their downregulation probably affected the homeostasis of shrimps. These findings provide novel insights into the mechanism of salinity adaptation in L. vannamei.
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Affiliation(s)
- Ardavan Farhadi
- Key Laboratory of Tropical Hydrobiology and Biotechnology of Hainan Province, Hainan Aquaculture Breeding Engineering Research Center, College of Marine Sciences, Hainan University, Haikou, Hainan, China
| | - Yan Liu
- School of Life Sciences, East China Normal University, Shanghai, China
| | - Chang Xu
- Key Laboratory of Tropical Hydrobiology and Biotechnology of Hainan Province, Hainan Aquaculture Breeding Engineering Research Center, College of Marine Sciences, Hainan University, Haikou, Hainan, China
| | - Xiaodan Wang
- School of Life Sciences, East China Normal University, Shanghai, China
| | - Erchao Li
- Key Laboratory of Tropical Hydrobiology and Biotechnology of Hainan Province, Hainan Aquaculture Breeding Engineering Research Center, College of Marine Sciences, Hainan University, Haikou, Hainan, China
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3
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Fleites LA, Johnson R, Kruse AR, Nachman RJ, Hall DG, MacCoss M, Heck ML. Peptidomics Approaches for the Identification of Bioactive Molecules from Diaphorina citri. J Proteome Res 2020; 19:1392-1408. [PMID: 32037832 DOI: 10.1021/acs.jproteome.9b00509] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Huanglongbing (HLB), a deadly citrus disease, is primarily associated with Candidatus Liberibacter asiaticus (CLas) and spread by the hemipteran insect Diaphorina citri. Control strategies to combat HLB are urgently needed. In this work, we developed and compared workflows for the extraction of the D. citri peptidome, a dynamic set of polypeptides produced by proteolysis and other cellular processes. High-resolution mass spectrometry revealed bias among methods reflecting the physiochemical properties of the peptides: while TCA/acetone-based methods resulted in enrichment of C-terminally amidated peptides, a modification characteristic of bioactive peptides, larger peptides were overrepresented in the aqueous phase of chloroform/methanol extracts, possibly indicative of reduced co-analytical degradation during sample preparation. Parallel reaction monitoring (PRM) was used to validate the structure and upregulation of peptides derived from hemocyanin, a D. citri immune system protein, in insects reared on healthy and CLas-infected trees. Mining of the data sets also revealed 122 candidate neuropeptides, including PK/PBAN family neuropeptides and kinins, biostable analogs of which have known insecticidal properties. Taken together, this information yields new, in-depth insights into peptidomics methodology. Additionally, the putative neuropeptides identified may lead to psyllid mortality if applied to or expressed in citrus, consequently blocking the spread of HLB disease in citrus groves.
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Affiliation(s)
- Laura A Fleites
- Boyce Thompson Institute for Plant Research, Ithaca, New York 14853, United States.,USDA Agricultural Research Service, Robert W. Holley Center for Agriculture and Health, Ithaca, New York, 14853-2901, United States.,Department of Plant Pathology and Plant Microbe Biology, Cornell University, Ithaca, New York 14850-5905, United States
| | - Richard Johnson
- Department of Genome Sciences, University of Washington, Seattle, Washington 98195, United States
| | - Angela R Kruse
- Boyce Thompson Institute for Plant Research, Ithaca, New York 14853, United States.,Department of Plant Pathology and Plant Microbe Biology, Cornell University, Ithaca, New York 14850-5905, United States
| | - Ronald J Nachman
- USDA Agricultural Research Service, Insect Control and Cotton Disease Research Unit, College Station, Texas 77845, United States
| | - David G Hall
- USDA Agricultural Research Service, US Horticulture Research Laboratory, Fort Pierce, Florida 34945, United States
| | - Michael MacCoss
- Department of Genome Sciences, University of Washington, Seattle, Washington 98195, United States
| | - Michelle L Heck
- Boyce Thompson Institute for Plant Research, Ithaca, New York 14853, United States.,USDA Agricultural Research Service, Robert W. Holley Center for Agriculture and Health, Ithaca, New York, 14853-2901, United States.,Department of Plant Pathology and Plant Microbe Biology, Cornell University, Ithaca, New York 14850-5905, United States
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4
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Asada H, Inoue A, Ngako Kadji FM, Hirata K, Shiimura Y, Im D, Shimamura T, Nomura N, Iwanari H, Hamakubo T, Kusano-Arai O, Hisano H, Uemura T, Suno C, Aoki J, Iwata S. The Crystal Structure of Angiotensin II Type 2 Receptor with Endogenous Peptide Hormone. Structure 2019; 28:418-425.e4. [PMID: 31899086 DOI: 10.1016/j.str.2019.12.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 11/11/2019] [Accepted: 12/05/2019] [Indexed: 12/17/2022]
Abstract
Angiotensin II (AngII) is a peptide hormone that plays a key role in regulating blood pressure, and its interactions with the G protein-coupled receptors, AngII type-1 receptor (AT1R) and AngII type-2 receptor (AT2R), are central to its mechanism of action. We solved the crystal structure of human AT2R bound to AngII and its specific antibody at 3.2-Å resolution. AngII (full agonist) and [Sar1, Ile8]-AngII (partial agonist) interact with AT2R in a similar fashion, except at the bottom of the AT2R ligand-binding pocket. In particular, the residues including Met1283.36, which constitute the deep end of the cavity, play important roles in angiotensin receptor (ATR) activation upon AngII binding. These differences that occur upon endogenous ligand binding may contribute to a structural change in AT2R, leading to normalization of the non-canonical coordination of helix 8. Our results will inform the design of more effective ligands for ATRs.
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Affiliation(s)
- Hidetsugu Asada
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan.
| | - Asuka Inoue
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan; Advanced Research & Development Programs for Medical Innovation (PRIME), Chiyoda, Tokyo 100-0004, Japan; Advanced Research & Development Programs for Medical Innovation (LEAP), Chiyoda, Tokyo 100-0004, Japan
| | | | - Kunio Hirata
- RIKEN, SPring-8 Center, Hyogo 679-5165, Japan; Japan Science and Technology Agency (JST), Precursory Research for Embryonic Science and Technology (PRESTO), Saitama 332-0012, Japan
| | - Yuki Shiimura
- Molecular Genetics, Institute of Life Science, Kurume University, Fukuoka 830-0011, Japan
| | - Dohyun Im
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan
| | - Tatsuro Shimamura
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan
| | - Norimichi Nomura
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan
| | - Hiroko Iwanari
- Department of Quantitative Biology and Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo 153-8904, Japan
| | - Takao Hamakubo
- Department of Quantitative Biology and Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo 153-8904, Japan
| | - Osamu Kusano-Arai
- Department of Quantitative Biology and Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo 153-8904, Japan
| | - Hiromi Hisano
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan
| | - Tomoko Uemura
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan
| | - Chiyo Suno
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan
| | - Junken Aoki
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan; Advanced Research & Development Programs for Medical Innovation (LEAP), Chiyoda, Tokyo 100-0004, Japan
| | - So Iwata
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan; RIKEN, SPring-8 Center, Hyogo 679-5165, Japan.
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5
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Singh KD, Unal H, Desnoyer R, Karnik SS. Mechanism of Hormone Peptide Activation of a GPCR: Angiotensin II Activated State of AT 1R Initiated by van der Waals Attraction. J Chem Inf Model 2019; 59:373-385. [PMID: 30608150 DOI: 10.1021/acs.jcim.8b00583] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We present a succession of structural changes involved in hormone peptide activation of a prototypical GPCR. Microsecond molecular dynamics simulation generated conformational ensembles reveal propagation of structural changes through key "microswitches" within human AT1R bound to native hormone. The endocrine octa-peptide angiotensin II (AngII) activates AT1R signaling in our bodies which maintains physiological blood pressure, electrolyte balance, and cardiovascular homeostasis. Excessive AT1R activation is associated with pathogenesis of hypertension and cardiovascular diseases which are treated by sartan drugs. The mechanism of AT1R inhibition by sartans has been elucidated by 2.8 Å X-ray structures, mutagenesis, and computational analyses. Yet, the mechanism of AT1R activation by AngII is unclear. The current study delineates an activation scheme initiated by AngII binding. A van der Waals "grasp" interaction between Phe8AngII with Ile2887.39 in AT1R induced mechanical strain pulling Tyr2927.43 and breakage of critical interhelical H-bonds, first between Tyr2927.43 and Val1083.32 and second between Asn1113.35 and Asn2957.46. Subsequently changes are observed in conserved microswitches DRYTM3, Yx7K(R)TM5, CWxPTM6, and NPxxYTM7 in AT1R. Activating the microswitches in the intracellular region of AT1R may trigger formation of the G-protein binding pocket as well as exposure of helix-8 to cytoplasm. Thus, the active-like conformation of AT1R is initiated by the van der Waals interaction of Phe8AngII with Ile2887.39, followed by systematic reorganization of critical interhelical H-bonds and activation of microswitches.
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Affiliation(s)
- Khuraijam Dhanachandra Singh
- Department of Molecular Cardiology, Lerner Research Institute , Cleveland Clinic Foundation , Cleveland , Ohio 44195 , United States
| | - Hamiyet Unal
- Department of Molecular Cardiology, Lerner Research Institute , Cleveland Clinic Foundation , Cleveland , Ohio 44195 , United States
| | - Russell Desnoyer
- Department of Molecular Cardiology, Lerner Research Institute , Cleveland Clinic Foundation , Cleveland , Ohio 44195 , United States
| | - Sadashiva S Karnik
- Department of Molecular Cardiology, Lerner Research Institute , Cleveland Clinic Foundation , Cleveland , Ohio 44195 , United States
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6
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Singh KD, Unal H, Desnoyer R, Karnik SS. Divergent Spatiotemporal Interaction of Angiotensin Receptor Blocking Drugs with Angiotensin Type 1 Receptor. J Chem Inf Model 2017; 58:182-193. [PMID: 29195045 DOI: 10.1021/acs.jcim.7b00424] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Crystal structures of the human angiotensin II type 1 receptor (AT1R) complex with the antihypertensive agent ZD7155 (PDB id: 4YAY ) and the blood pressure medication Benicar (PDB id: 4ZUD ) showed that binding poses of both antagonists are similar. This finding implies that clinically used angiotensin receptor blocking (ARB) drugs may interact in a similar fashion. However, clinically observed differences in pharmacological and therapeutic efficacies of ARBs lead to the question of whether the dynamic interactions of AT1R with ARBs vary. To address this, we performed induced-fit docking (IFD) of eight clinically used ARBs to AT1R followed by 200 ns molecular dynamic (MD) simulation. The experimental Ki values for ARBs correlated remarkably well with calculated free energy with R2 = 0.95 and 0.70 for AT1R-ARB models generated respectively by IFD and MD simulation. The eight ARB-AT1R complexes share a common set of binding residues. In addition, MD simulation results validated by mutagenesis data discovered distinctive spatiotemporal interactions that display unique bonding between an individual ARB and AT1R. These findings provide a reasonably broader picture reconciling the structure-based observations with clinical studies reporting efficacy variations for ARBs. The unique differences unraveled for ARBs in this study will be useful for structure-based design of the next generation of more potent and selective ARBs.
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Affiliation(s)
- Khuraijam Dhanachandra Singh
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Foundation , Cleveland, Ohio 44195, United States
| | - Hamiyet Unal
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Foundation , Cleveland, Ohio 44195, United States
| | - Russell Desnoyer
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Foundation , Cleveland, Ohio 44195, United States
| | - Sadashiva S Karnik
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Foundation , Cleveland, Ohio 44195, United States
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7
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Billard E, Létourneau M, Hébert TE, Chatenet D. Insight into the role of urotensin II-related peptide tyrosine residue in UT activation. Biochem Pharmacol 2017; 144:100-107. [DOI: 10.1016/j.bcp.2017.08.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Accepted: 08/03/2017] [Indexed: 12/16/2022]
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8
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Biased agonism/antagonism at the AngII-AT1 receptor: Implications for adrenal aldosterone production and cardiovascular therapy. Pharmacol Res 2017; 125:14-20. [PMID: 28511989 DOI: 10.1016/j.phrs.2017.05.009] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 05/03/2017] [Accepted: 05/11/2017] [Indexed: 12/23/2022]
Abstract
Many of the effects of angiotensin II (AngII), including adrenocortical aldosterone release, are mediated by the AngII type 1 receptor (AT1R), a receptor with essential roles in cardiovascular homeostasis. AT1R belongs to the G protein-coupled receptor (GPCR) superfamily, mainly coupling to the Gq/11 type of G proteins. However, it also signals through βarrestins, oftentimes in parallel to eliciting G protein-dependent signaling. This has spurred infinite possibilities for cardiovascular pharmacology, since various beneficial effects are purportedly exerted by AT1R via βarrestins, unlike AT1R-induced G protein-mediated pathways that usually result in damaging cardiovascular effects, including hypertension and aldosterone elevation. Over the past decade however, a number of studies from our group and others have suggested that AT1R-induced βarrestin signaling can also be damaging for the heart, similarly to the G protein-dependent one, with regard to aldosterone regulation. Additionally, AT1R-induced βarrestin signaling in astrocytes from certain areas of the brain may also play a significant role in central regulation of blood pressure and hypertension pathogenesis. These findings have provided the impetus for testing available angiotensin receptor blockers (ARBs) in their efficacy towards blocking both routes (i.e. both G protein- and βarrestin-dependent) of AT1R signaling in vitro and in vivo and also have promoted structure-activity relationship (SAR) studies for the AngII molecule in terms of βarrestin signaling to certain cellular effects, e.g. adrenal aldosterone production. In the present review, we will recount all of these recent studies on adrenal and astrocyte AT1R-dependent βarrestin signaling while underlining their implications for cardiovascular pathophysiology and therapy.
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McAnally D, Siddiquee K, Sharir H, Qi F, Phatak S, Li JL, Berg E, Fishman J, Smith L. A Systematic Approach to Identify Biased Agonists of the Apelin Receptor through High-Throughput Screening. SLAS DISCOVERY 2017; 22:867-878. [PMID: 28314120 DOI: 10.1177/2472555217699158] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Biased agonists are defined by their ability to selectively activate distinct signaling pathways of a receptor, and they hold enormous promise for the development of novel drugs that specifically elicit only the desired therapeutic response and avoid potential adverse effects. Unfortunately, most high-throughput screening (HTS) assays are designed to detect signaling of G protein-coupled receptors (GPCRs) downstream of either G protein or β-arrestin-mediated signaling but not both. A comprehensive drug discovery program seeking biased agonists must employ assays that report on the activity of each compound at multiple discrete pathways, particularly for HTS campaigns. Here, we report a systematic approach to the identification of biased agonists of human apelin receptor (APJ). We synthesized 448 modified versions of apelin and screened them against a cascade of cell-based assays, including intracellular cAMP and β-arrestin recruitment to APJ, simultaneously. The screen yielded potent and highly selective APJ agonists. Representative hits displaying preferential signaling via either G-protein or β-arrestin were subjected to a battery of confirmation assays. These biased agonists will be useful as tools to probe the function and pharmacology of APJ and provide proof of concept of our systematic approach to the discovery of biased ligands. This approach is likely universally applicable to the search for biased agonists of GPCRs.
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Affiliation(s)
- Danielle McAnally
- 1 Conrad Prebys Center for Chemical Genomics, and Center for Metabolic Origins of Disease, Cardiovascular Metabolism Program, Sanford Burnham Prebys Medical Discovery Institute at Lake Nona, Orlando, FL, USA.,2 Center for Metabolic Origins of Disease, Cardiovascular Metabolism Program, Sanford Burnham Prebys Medical Discovery Institute at Lake Nona, Orlando, FL, USA
| | - Khandaker Siddiquee
- 1 Conrad Prebys Center for Chemical Genomics, and Center for Metabolic Origins of Disease, Cardiovascular Metabolism Program, Sanford Burnham Prebys Medical Discovery Institute at Lake Nona, Orlando, FL, USA.,2 Center for Metabolic Origins of Disease, Cardiovascular Metabolism Program, Sanford Burnham Prebys Medical Discovery Institute at Lake Nona, Orlando, FL, USA
| | - Haleli Sharir
- 1 Conrad Prebys Center for Chemical Genomics, and Center for Metabolic Origins of Disease, Cardiovascular Metabolism Program, Sanford Burnham Prebys Medical Discovery Institute at Lake Nona, Orlando, FL, USA.,2 Center for Metabolic Origins of Disease, Cardiovascular Metabolism Program, Sanford Burnham Prebys Medical Discovery Institute at Lake Nona, Orlando, FL, USA
| | - Feng Qi
- 1 Conrad Prebys Center for Chemical Genomics, and Center for Metabolic Origins of Disease, Cardiovascular Metabolism Program, Sanford Burnham Prebys Medical Discovery Institute at Lake Nona, Orlando, FL, USA
| | - Sharangdhar Phatak
- 1 Conrad Prebys Center for Chemical Genomics, and Center for Metabolic Origins of Disease, Cardiovascular Metabolism Program, Sanford Burnham Prebys Medical Discovery Institute at Lake Nona, Orlando, FL, USA
| | - Jian-Liang Li
- 1 Conrad Prebys Center for Chemical Genomics, and Center for Metabolic Origins of Disease, Cardiovascular Metabolism Program, Sanford Burnham Prebys Medical Discovery Institute at Lake Nona, Orlando, FL, USA
| | - Eric Berg
- 3 21st Century Biochemicals Inc., Marlborough, MA, USA
| | | | - Layton Smith
- 1 Conrad Prebys Center for Chemical Genomics, and Center for Metabolic Origins of Disease, Cardiovascular Metabolism Program, Sanford Burnham Prebys Medical Discovery Institute at Lake Nona, Orlando, FL, USA.,2 Center for Metabolic Origins of Disease, Cardiovascular Metabolism Program, Sanford Burnham Prebys Medical Discovery Institute at Lake Nona, Orlando, FL, USA
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10
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Vauquelin G, Fierens FLP, Gáborik Z, Le Minh T, De Backer JP, Hunyady L, Vanderheyden PML. Role of basic amino acids of the human angiotensin type 1 receptor in the binding of the non-peptide antagonist candesartan. J Renin Angiotensin Aldosterone Syst 2016; 2:S32-S36. [DOI: 10.1177/14703203010020010501] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
To explain the insurmountable/long-lasting binding of biphenyltetrazole-containing AT1-receptor antagonists such as candesartan, to the human angiotensin II type 1-receptor, a model is proposed in which the basic amino acids Lys199 and Arg 167 of the receptor interact respectively with the carboxylate and the tetrazole group of the antagonists. To validate this model, we have investigated the impact of substitution of Lys199 by Ala or Gln and of Arg167 by Ala on the binding properties of [3H]candesartan and on competition binding by candesartan, EXP3174, irbesartan, losartan, angiotensin II (Ang II) and [Sar1-Ile8]angiotensin. Our results indicate that both amino acids play an important role in the AT1-receptor ligand binding. Whereas the negative charge of Lys 199 is involved in an ionic bond with the end-standing carboxylate group of the peptide ligands, its polarity also contributes to the non-peptide antagonist binding. Substitution of Arg167 by Ala completely abolished [3H]Ang II, as well as [3H] candesartan, binding. Whereas these results are in line with the proposed model, it cannot be excluded that both amino acid residues are important for the structural integrity of the AT1-receptor with respect to its ligand binding properties.
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Affiliation(s)
- Georges Vauquelin
- Department of Molecular and Biochemical Pharmacology,
Institute for Molecular Biology and Biotechnology, Free University of Brussels
(VUB), B-1640 Sint-Genesius Rode, Belgium, gvauquel@ vub.ac.be
| | - Frederik LP Fierens
- Department of Molecular and Biochemical Pharmacology,
Institute for Molecular Biology and Biotechnology, Free University of Brussels
(VUB), B-1640 Sint-Genesius Rode, Belgium
| | - Zsuzsanna Gáborik
- Department of Physiology, Semmelweis University Medical
School, H-1444 Budapest, PO Box 259, Hungary
| | - Tam Le Minh
- Department of Molecular and Biochemical Pharmacology,
Institute for Molecular Biology and Biotechnology, Free University of Brussels
(VUB), B-1640 Sint-Genesius Rode, Belgium
| | - Jean-Paul De Backer
- Department of Molecular and Biochemical Pharmacology,
Institute for Molecular Biology and Biotechnology, Free University of Brussels
(VUB), B-1640 Sint-Genesius Rode, Belgium
| | - László Hunyady
- Department of Physiology, Semmelweis University Medical
School, H-1444 Budapest, PO Box 259, Hungary
| | - Patrick ML Vanderheyden
- Department of Molecular and Biochemical Pharmacology,
Institute for Molecular Biology and Biotechnology, Free University of Brussels
(VUB), B-1640 Sint-Genesius Rode, Belgium
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11
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Hunyady L, Gáborik Z, Vauquelin G, Catt KJ. Review: Structural requirements for signalling and regulation of AT1-receptors. J Renin Angiotensin Aldosterone Syst 2016; 2:S16-S23. [DOI: 10.1177/14703203010020010301] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Affiliation(s)
- László Hunyady
- Department of Physiology, Semmelweis University Medical
School, Budapest, Hungary,
| | - Zsuzsanna Gáborik
- Department of Physiology, Semmelweis University Medical
School, Budapest, Hungary
| | - Georges Vauquelin
- Department of Molecular and Biochemical Pharmacology,
Institute of Molecular Biology and Biotechnology, Free University of Brussels
(VUB), Sint-Genesius Rode, Belgium
| | - Kevin J Catt
- Endocrinology and Reproduction Research Branch, National
Institute of Child Health and Human Development, National Institutes of Health,
Bethesda, USA
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12
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Distinctions between non-peptide angiotensin II AT1-receptor antagonists. J Renin Angiotensin Aldosterone Syst 2016; 2:S24-S31. [DOI: 10.1177/14703203010020010401] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
A far-reaching understanding of the molecular action mechanism of AT1-receptor antagonists (AIIAs) was obtained by using CHO cells expressing transfected human AT 1-receptors. In this model, direct [3H]-antagonist binding and inhibition of agonist-induced responses (inositol phosphate accumulation) can be measured under identical experimental conditions. Whereas preincubation with a surmountable AIIA (losartan) causes parallel shifts of the angiotensin II (Ang II) concentration-response curve, insurmountable antagonists also cause partial (i.e., 30% for irbesartan, 50% for valsartan, 70% for EXP3174,) to almost complete (95% for candesartan) reductions of the maximal response. The main conclusions are that all investigated antagonists are competitive with respect to Ang II. They bind to a common or overlapping site on the receptor in a mutually exclusive way. Insurmountable inhibition is related to the slow dissociation rate of the antagonist-receptor complex (t 1/2 of 7 minutes for irbesartan, 17 minutes for valsartan, 30 minutes for EXP3174 and 120 minutes for candesartan). Antagonist-bound AT1-receptors can adopt a fast and a slow reversible state. This is responsible for the partial nature of the insurmountable inhibition. The long-lasting effect of candesartan, the active metabolite of candesartan cilexetil, in vascular smooth muscle contraction studies, as well as in in vivo experiments on rat and in clinical studies, is compatible with its slow dissociation from, and continuous recycling between AT1-receptors. This recycling, or `rebinding' takes place because of the very high affinity of candesartan for the AT1-receptor.
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13
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Valero TR, Sturchler E, Jafferjee M, Rengo G, Magafa V, Cordopatis P, McDonald P, Koch WJ, Lymperopoulos A. Structure-activity relationship study of angiotensin II analogs in terms of β-arrestin-dependent signaling to aldosterone production. Pharmacol Res Perspect 2016; 4:e00226. [PMID: 27069636 PMCID: PMC4804318 DOI: 10.1002/prp2.226] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 02/02/2016] [Accepted: 02/05/2016] [Indexed: 12/11/2022] Open
Abstract
The known angiotensin II (AngII) physiological effect of aldosterone synthesis and secretion induction, a steroid hormone that contributes to the pathology of postmyocardial infarction (MI) heart failure (HF), is mediated by both Gq/11 proteins and β-arrestins, both of which couple to the AngII type 1 receptors (AT1Rs) of adrenocortical zona glomerulosa (AZG) cells. Over the past several years, AngII analogs with increased selectivity ("bias") toward β-arrestin-dependent signaling at the AT1R have been designed and described, starting with SII, the gold-standard β-arrestin-"biased" AngII analog. In this study, we examined the relative potencies of an extensive series of AngII peptide analogs at relative activation of G proteins versus β-arrestins by the AT1R. The major structural difference of these peptides from SII was their varied substitutions at position 5, rather than position 4 of native AngII. Three of them were found biased for β-arrestin activation and extremely potent at stimulating aldosterone secretion in AZG cells in vitro, much more potent than SII in that regard. Finally, the most potent of these three ([Sar(1), Cys(Et)(5), Leu(8)]-AngII, CORET) was further examined in post-MI rats progressing to HF and overexpressing adrenal β-arrestin1 in vivo. Consistent with the in vitro studies, CORET was found to exacerbate the post-MI hyperaldosteronism, and, consequently, cardiac function of the post-MI animals in vivo. Finally, our data suggest that increasing the size of position 5 of the AngII peptide sequence results in directly proportional increases in AT1R-dependent β-arrestin activation. These findings provide important insights for AT1R pharmacology and future AngII-targeted drug development.
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Affiliation(s)
- Thairy Reyes Valero
- Department of Pharmaceutical Sciences Laboratory for the Study of Neurohormonal Control of the Circulation Nova Southeastern University College of Pharmacy Fort Lauderdale Florida 33328
| | | | - Malika Jafferjee
- Department of Pharmaceutical Sciences Laboratory for the Study of Neurohormonal Control of the Circulation Nova Southeastern University College of Pharmacy Fort Lauderdale Florida 33328
| | - Giuseppe Rengo
- Salvatore Maugeri Foundation-Scientific Institute of Telese Terme Telese Terme Italy
| | - Vassiliki Magafa
- Department of Pharmacy Laboratory of Pharmacognosy & Chemistry of Natural Products University of Patras Patras Greece
| | - Paul Cordopatis
- Department of Pharmacy Laboratory of Pharmacognosy & Chemistry of Natural Products University of Patras Patras Greece
| | - Patricia McDonald
- Translational Research Institute Scripps Florida Jupiter Florida 33458
| | - Walter J Koch
- Center for Translational Medicine Temple University Philadelphia Pennsylvania 19140
| | - Anastasios Lymperopoulos
- Department of Pharmaceutical Sciences Laboratory for the Study of Neurohormonal Control of the Circulation Nova Southeastern University College of Pharmacy Fort Lauderdale Florida 33328
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14
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Karnik SS, Unal H, Kemp JR, Tirupula KC, Eguchi S, Vanderheyden PML, Thomas WG. International Union of Basic and Clinical Pharmacology. XCIX. Angiotensin Receptors: Interpreters of Pathophysiological Angiotensinergic Stimuli [corrected]. Pharmacol Rev 2015; 67:754-819. [PMID: 26315714 PMCID: PMC4630565 DOI: 10.1124/pr.114.010454] [Citation(s) in RCA: 215] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The renin angiotensin system (RAS) produced hormone peptides regulate many vital body functions. Dysfunctional signaling by receptors for RAS peptides leads to pathologic states. Nearly half of humanity today would likely benefit from modern drugs targeting these receptors. The receptors for RAS peptides consist of three G-protein-coupled receptors—the angiotensin II type 1 receptor (AT1 receptor), the angiotensin II type 2 receptor (AT2 receptor), the MAS receptor—and a type II trans-membrane zinc protein—the candidate angiotensin IV receptor (AngIV binding site). The prorenin receptor is a relatively new contender for consideration, but is not included here because the role of prorenin receptor as an independent endocrine mediator is presently unclear. The full spectrum of biologic characteristics of these receptors is still evolving, but there is evidence establishing unique roles of each receptor in cardiovascular, hemodynamic, neurologic, renal, and endothelial functions, as well as in cell proliferation, survival, matrix-cell interaction, and inflammation. Therapeutic agents targeted to these receptors are either in active use in clinical intervention of major common diseases or under evaluation for repurposing in many other disorders. Broad-spectrum influence these receptors produce in complex pathophysiological context in our body highlights their role as precise interpreters of distinctive angiotensinergic peptide cues. This review article summarizes findings published in the last 15 years on the structure, pharmacology, signaling, physiology, and disease states related to angiotensin receptors. We also discuss the challenges the pharmacologist presently faces in formally accepting newer members as established angiotensin receptors and emphasize necessary future developments.
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Affiliation(s)
- Sadashiva S Karnik
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
| | - Hamiyet Unal
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
| | - Jacqueline R Kemp
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
| | - Kalyan C Tirupula
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
| | - Satoru Eguchi
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
| | - Patrick M L Vanderheyden
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
| | - Walter G Thomas
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
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15
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Abstract
There are many reported examples of small structural modifications to GPCR-targeted ligands leading to major changes in their functional activity, converting agonists into antagonists or vice versa. These shifts in functional activity are often accompanied by negligible changes in binding affinity. The current perspective focuses on outlining and analyzing various approaches that have been used to interconvert GPCR agonists, partial agonists, and antagonists in order to achieve the intended functional activity at a GPCR of therapeutic interest. An improved understanding of specific structural modifications that are likely to alter the functional activity of a GPCR ligand may be of use to researchers designing GPCR-targeted drugs and/or probe compounds, specifically in cases where a particular ligand exhibits good potency but not the preferred functional activity at the GPCR of choice.
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Affiliation(s)
- Peter I Dosa
- Institute for Therapeutics Discovery and Development, Department of Medicinal Chemistry, University of Minnesota , 717 Delaware Street SE, Minneapolis, Minnesota 55414, United States
| | - Elizabeth Ambrose Amin
- Department of Medicinal Chemistry and Minnesota Supercomputing Institute for Advanced Computational Research, University of Minnesota , 717 Delaware Street SE, Minneapolis, Minnesota 55414, United States
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16
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Cabana J, Holleran B, Leduc R, Escher E, Guillemette G, Lavigne P. Identification of Distinct Conformations of the Angiotensin-II Type 1 Receptor Associated with the Gq/11 Protein Pathway and the β-Arrestin Pathway Using Molecular Dynamics Simulations. J Biol Chem 2015; 290:15835-15854. [PMID: 25934394 DOI: 10.1074/jbc.m114.627356] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Indexed: 01/14/2023] Open
Abstract
Biased signaling represents the ability of G protein-coupled receptors to engage distinct pathways with various efficacies depending on the ligand used or on mutations in the receptor. The angiotensin-II type 1 (AT1) receptor, a prototypical class A G protein-coupled receptor, can activate various effectors upon stimulation with the endogenous ligand angiotensin-II (AngII), including the Gq/11 protein and β-arrestins. It is believed that the activation of those two pathways can be associated with distinct conformations of the AT1 receptor. To verify this hypothesis, microseconds of molecular dynamics simulations were computed to explore the conformational landscape sampled by the WT-AT1 receptor, the N111G-AT1 receptor (constitutively active and biased for the Gq/11 pathway), and the D74N-AT1 receptor (biased for the β-arrestin1 and -2 pathways) in their apo-forms and in complex with AngII. The molecular dynamics simulations of the AngII-WT-AT1, N111G-AT1, and AngII-N111G-AT1 receptors revealed specific structural rearrangements compared with the initial and ground state of the receptor. Simulations of the D74N-AT1 receptor revealed that the mutation stabilizes the receptor in the initial ground state. The presence of AngII further stabilized the ground state of the D74N-AT1 receptor. The biased agonist [Sar(1),Ile(8)]AngII also showed a preference for the ground state of the WT-AT1 receptor compared with AngII. These results suggest that activation of the Gq/11 pathway is associated with a specific conformational transition stabilized by the agonist, whereas the activation of the β-arrestin pathway is linked to the stabilization of the ground state of the receptor.
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Affiliation(s)
- Jérôme Cabana
- Departments of Pharmacology, Faculty of Medicine and Health Sciences, Institut de Pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4; PROTEO (Quebec Network on Protein Structure, Function, and Engineering), Université Laval, Québec, Québec G1V 0A6, Canada
| | - Brian Holleran
- Departments of Pharmacology, Faculty of Medicine and Health Sciences, Institut de Pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4
| | - Richard Leduc
- Departments of Pharmacology, Faculty of Medicine and Health Sciences, Institut de Pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4
| | - Emanuel Escher
- Departments of Pharmacology, Faculty of Medicine and Health Sciences, Institut de Pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4
| | - Gaétan Guillemette
- Departments of Pharmacology, Faculty of Medicine and Health Sciences, Institut de Pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4
| | - Pierre Lavigne
- PROTEO (Quebec Network on Protein Structure, Function, and Engineering), Université Laval, Québec, Québec G1V 0A6, Canada; Biochemistry, Faculty of Medicine and Health Sciences, Institut de Pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4.
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17
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Domazet I, Holleran BJ, Richard A, Vandenberghe C, Lavigne P, Escher E, Leduc R, Guillemette G. Characterization of Angiotensin II Molecular Determinants Involved in AT1 Receptor Functional Selectivity. Mol Pharmacol 2015; 87:982-95. [PMID: 25808928 DOI: 10.1124/mol.114.097337] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 03/24/2015] [Indexed: 01/14/2023] Open
Abstract
The octapeptide angiotensin II (AngII) exerts a variety of cardiovascular effects through the activation of the AngII type 1 receptor (AT1), a G protein-coupled receptor. The AT1 receptor engages and activates several signaling pathways, including heterotrimeric G proteins Gq and G12, as well as the extracellular signal-regulated kinases (ERK) 1/2 pathway. Additionally, following stimulation, βarrestin is recruited to the AT1 receptor, leading to receptor desensitization. It is increasingly recognized that specific ligands selectively bind and favor the activation of some signaling pathways over others, a concept termed ligand bias or functional selectivity. A better understanding of the molecular basis of functional selectivity may lead to the development of better therapeutics with fewer adverse effects. In the present study, we developed assays allowing the measurement of six different signaling modalities of the AT1 receptor. Using a series of AngII peptide analogs that were modified in positions 1, 4, and 8, we sought to better characterize the molecular determinants of AngII that underlie functional selectivity of the AT1 receptor in human embryonic kidney 293 cells. The results reveal that position 1 of AngII does not confer functional selectivity, whereas position 4 confers a bias toward ERK signaling over Gq signaling, and position 8 confers a bias toward βarrestin recruitment over ERK activation and Gq signaling. Interestingly, the analogs modified in position 8 were also partial agonists of the protein kinase C (PKC)-dependent ERK pathway via atypical PKC isoforms PKCζ and PKCι.
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Affiliation(s)
- Ivana Domazet
- Department of Pharmacology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Brian J Holleran
- Department of Pharmacology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Alexandra Richard
- Department of Pharmacology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Camille Vandenberghe
- Department of Pharmacology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Pierre Lavigne
- Department of Pharmacology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Emanuel Escher
- Department of Pharmacology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Richard Leduc
- Department of Pharmacology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Gaétan Guillemette
- Department of Pharmacology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
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18
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Balakumar P, Jagadeesh G. Structural determinants for binding, activation, and functional selectivity of the angiotensin AT1 receptor. J Mol Endocrinol 2014; 53:R71-92. [PMID: 25013233 DOI: 10.1530/jme-14-0125] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The renin-angiotensin system (RAS) plays an important role in the pathophysiology of cardiovascular disorders. Pharmacologic interventions targeting the RAS cascade have led to the discovery of renin inhibitors, angiotensin-converting enzyme inhibitors, and AT(1) receptor blockers (ARBs) to treat hypertension and some cardiovascular and renal disorders. Mutagenesis and modeling studies have revealed that differential functional outcomes are the results of multiple active states conformed by the AT(1) receptor upon interaction with angiotensin II (Ang II). The binding of agonist is dependent on both extracellular and intramembrane regions of the receptor molecule, and as a consequence occupies more extensive area of the receptor than a non-peptide antagonist. Both agonist and antagonist bind to the same intramembrane regions to interfere with each other's binding to exhibit competitive, surmountable interaction. The nature of interactions with the amino acids in the receptor is different for each of the ARBs given the small differences in the molecular structure between drugs. AT(1) receptors attain different conformation states after binding various Ang II analogues, resulting in variable responses through activation of multiple signaling pathways. These include both classical and non-classical pathways mediated through growth factor receptor transactivations, and provide cross-communication between downstream signaling molecules. The structural requirements for AT(1) receptors to activate extracellular signal-regulated kinases 1 and 2 through G proteins, or G protein-independently through β-arrestin, are different. We review the structural and functional characteristics of Ang II and its analogs and antagonists, and their interaction with amino acid residues in the AT(1) receptor.
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Affiliation(s)
- Pitchai Balakumar
- Pharmacology UnitFaculty of Pharmacy, AIMST University, Semeling, 08100 Bedong, Kedah Darul Aman, MalaysiaDivision of Cardiovascular and Renal ProductsCenter for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, Maryland 20993, USA
| | - Gowraganahalli Jagadeesh
- Pharmacology UnitFaculty of Pharmacy, AIMST University, Semeling, 08100 Bedong, Kedah Darul Aman, MalaysiaDivision of Cardiovascular and Renal ProductsCenter for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, Maryland 20993, USA
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19
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Tirupula KC, Desnoyer R, Speth RC, Karnik SS. Atypical signaling and functional desensitization response of MAS receptor to peptide ligands. PLoS One 2014; 9:e103520. [PMID: 25068582 PMCID: PMC4113456 DOI: 10.1371/journal.pone.0103520] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2014] [Accepted: 07/01/2014] [Indexed: 11/19/2022] Open
Abstract
MAS is a G protein-coupled receptor (GPCR) implicated in multiple physiological processes. Several physiological peptide ligands such as angiotensin-(1-7), angiotensin fragments and neuropeptide FF (NPFF) are reported to act on MAS. Studies of conventional G protein signaling and receptor desensitization upon stimulation of MAS with the peptide ligands are limited so far. Therefore, we systematically analyzed G protein signals activated by the peptide ligands. MAS-selective non-peptide ligands that were previously shown to activate G proteins were used as controls for comparison on a common cell based assay platform. Activation of MAS by the non-peptide agonist (1) increased intracellular calcium and D-myo-inositol-1-phosphate (IP1) levels which are indicative of the activation of classical Gαq-phospholipase C signaling pathways, (2) decreased Gαi mediated cAMP levels and (3) stimulated Gα12-dependent expression of luciferase reporter. In all these assays, MAS exhibited strong constitutive activity that was inhibited by the non-peptide inverse agonist. Further, in the calcium response assay, MAS was resistant to stimulation by a second dose of the non-peptide agonist after the first activation has waned suggesting functional desensitization. In contrast, activation of MAS by the peptide ligand NPFF initiated a rapid rise in intracellular calcium with very weak IP1 accumulation which is unlike classical Gαq-phospholipase C signaling pathway. NPFF only weakly stimulated MAS-mediated activation of Gα12 and Gαi signaling pathways. Furthermore, unlike non-peptide agonist-activated MAS, NPFF-activated MAS could be readily re-stimulated the second time by the agonists. Functional assays with key ligand binding MAS mutants suggest that NPFF and non-peptide ligands bind to overlapping regions. Angiotensin-(1-7) and other angiotensin fragments weakly potentiated an NPFF-like calcium response at non-physiological concentrations (≥100 µM). Overall, our data suggest that peptide ligands induce atypical signaling and functional desensitization of MAS.
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Affiliation(s)
- Kalyan C. Tirupula
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Russell Desnoyer
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Robert C. Speth
- Department of Pharmaceutical Sciences, College of Pharmacy, Nova Southeastern University, Fort Lauderdale, Florida, United States of America
| | - Sadashiva S. Karnik
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
- * E-mail:
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20
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Unal H, Karnik SS. Constitutive activity in the angiotensin II type 1 receptor: discovery and applications. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2014; 70:155-74. [PMID: 24931196 DOI: 10.1016/b978-0-12-417197-8.00006-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The pathophysiological actions of the renin-angiotensin system hormone, angiotensin II (AngII), are mainly mediated by the AngII type 1 (AT1) receptor, a GPCR. The intrinsic spontaneous activity of the AT1 receptor in native tissues is difficult to detect due to its low expression levels. However, factors such as the membrane environment, interaction with autoantibodies, and mechanical stretch are known to increase G protein signaling in the absence of AngII. Naturally occurring and disease-causing activating mutations have not been identified in AT1 receptor. Constitutively active mutants (CAMs) of AT1 receptor have been engineered using molecular modeling and site-directed mutagenesis approaches among which substitution of Asn(111) in the transmembrane helix III with glycine or serine results in the highest basal activity of the receptor. Transgenic animal models expressing the CAM AT1 receptors that mimic various in vivo disease conditions have been useful research tools for discovering the pathophysiological role of AT1 receptor and evaluating the therapeutic potential of inverse agonists. This chapter summarizes the studies on the constitutive activity of AT1 receptor in recombinant as well as physiological systems. The impact of the availability of CAM AT1 receptors on our understanding of the molecular mechanisms underlying receptor activation and inverse agonism is described.
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Affiliation(s)
- Hamiyet Unal
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Sadashiva S Karnik
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA.
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21
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Wu J, You J, Wang S, Zhang L, Gong H, Zou Y. Insights Into the Activation and Inhibition of Angiotensin II Type 1 Receptor in the Mechanically Loaded Heart. Circ J 2014; 78:1283-9. [DOI: 10.1253/circj.cj-14-0470] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Jian Wu
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University
| | - Jieyun You
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University
| | - Shijun Wang
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University
| | - Li Zhang
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University
| | - Hui Gong
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University
| | - Yunzeng Zou
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University
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22
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Reassessment of the unique mode of binding between angiotensin II type 1 receptor and their blockers. PLoS One 2013; 8:e79914. [PMID: 24260317 PMCID: PMC3832659 DOI: 10.1371/journal.pone.0079914] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Accepted: 09/25/2013] [Indexed: 11/30/2022] Open
Abstract
While the molecular structures of angiotensin II (Ang II) type 1 (AT1) receptor blockers (ARBs) are very similar, they are also slightly different. Although each ARB has been shown to exhibit a unique mode of binding to AT1 receptor, different positions of the AT1 receptor have been analyzed and computational modeling has been performed using different crystal structures for the receptor as a template and different kinds of software. Therefore, we systematically analyzed the critical positions of the AT1 receptor, Tyr113, Tyr184, Lys199, His256 and Gln257 using a mutagenesis study, and subsequently performed computational modeling of the binding of ARBs to AT1 receptor using CXCR4 receptor as a new template and a single version of software. The interactions between Tyr113 in the AT1 receptor and the hydroxyl group of olmesartan, between Lys199 and carboxyl or tetrazole groups, and between His256 or Gln257 and the tetrazole group were studied. The common structure, a tetrazole group, of most ARBs similarly bind to Lys199, His256 and Gln257 of AT1 receptor. Lys199 in the AT1 receptor binds to the carboxyl group of EXP3174, candesartan and azilsartan, whereas oxygen in the amidecarbonyl group of valsartan may bind to Lys199. The benzimidazole portion of telmisartan may bind to a lipophilic pocket that includes Tyr113. On the other hand, the n-butyl group of irbesartan may bind to Tyr113. In conclusion, we confirmed that the slightly different structures of ARBs may be critical for binding to AT1 receptor and for the formation of unique modes of binding.
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23
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Sungkaworn T, Jiarpinitnun C, Chaiyakunvat P, Chatsudthipong V. Bivalent angiotensin II suppresses oxidative stress-induced hyper-responsiveness of angiotensin II receptor type I. Eur J Med Chem 2013; 63:629-34. [DOI: 10.1016/j.ejmech.2013.02.041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Revised: 01/07/2013] [Accepted: 02/25/2013] [Indexed: 11/16/2022]
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24
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Miura SI, Matsuo Y, Nakayama A, Tomita S, Suematsu Y, Saku K. Ability of the new AT1 receptor blocker azilsartan to block angiotensin II-induced AT1 receptor activation after wash-out. J Renin Angiotensin Aldosterone Syst 2013; 15:7-12. [DOI: 10.1177/1470320313482170] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Shin-ichiro Miura
- Department of Cardiology, Fukuoka University Hospital, Japan
- Department of Molecular Cardiovascular Therapeutics, Fukuoka University School of Medicine, Japan
- Department of Molecular Cardiology, Lerner Research Institute, The Cleveland Clinic Foundation, USA
| | - Yoshino Matsuo
- Department of Cardiology, Fukuoka University Hospital, Japan
| | - Asuka Nakayama
- Department of Cardiology, Fukuoka University Hospital, Japan
| | - Sayo Tomita
- Department of Cardiology, Fukuoka University Hospital, Japan
| | | | - Keijiro Saku
- Department of Cardiology, Fukuoka University Hospital, Japan
- Department of Molecular Cardiovascular Therapeutics, Fukuoka University School of Medicine, Japan
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25
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Unal H, Jagannathan R, Bhatnagar A, Tirupula K, Desnoyer R, Karnik SS. Long range effect of mutations on specific conformational changes in the extracellular loop 2 of angiotensin II type 1 receptor. J Biol Chem 2012; 288:540-51. [PMID: 23139413 DOI: 10.1074/jbc.m112.392514] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The topology of the second extracellular loop (ECL2) and its interaction with ligands is unique in each G protein-coupled receptor. When the orthosteric ligand pocket located in the transmembrane (TM) domain is occupied, ligand-specific conformational changes occur in the ECL2. In more than 90% of G protein-coupled receptors, ECL2 is tethered to the third TM helix via a disulfide bond. Therefore, understanding the extent to which the TM domain and ECL2 conformations are coupled is useful. To investigate this, we examined conformational changes in ECL2 of the angiotensin II type 1 receptor (AT1R) by introducing mutations in distant sites that alter the activation state equilibrium of the AT1R. Differential accessibility of reporter cysteines introduced at four conformation-sensitive sites in ECL2 of these mutants was measured. Binding of the agonist angiotensin II (AngII) and inverse agonist losartan in wild-type AT1R changed the accessibility of reporter cysteines, and the pattern was consistent with ligand-specific "lid" conformations of ECL2. Without agonist stimulation, the ECL2 in the gain of function mutant N111G assumed a lid conformation similar to AngII-bound wild-type AT1R. In the presence of inverse agonists, the conformation of ECL2 in the N111G mutant was similar to the inactive state of wild-type AT1R. In contrast, AngII did not induce a lid conformation in ECL2 in the loss of function D281A mutant, which is consistent with the reduced AngII binding affinity in this mutant. However, a lid conformation was induced by [Sar(1),Gln(2),Ile(8)] AngII, a specific analog that binds to the D281A mutant with better affinity than AngII. These results provide evidence for the emerging paradigm of domain coupling facilitated by long range interactions at distant sites on the same receptor.
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Affiliation(s)
- Hamiyet Unal
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195, USA
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26
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Miura SI, Okabe A, Matsuo Y, Karnik SS, Saku K. Unique binding behavior of the recently approved angiotensin II receptor blocker azilsartan compared with that of candesartan. Hypertens Res 2012; 36:134-9. [PMID: 23034464 DOI: 10.1038/hr.2012.147] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The angiotensin II type 1 (AT(1)) receptor blocker (ARB) candesartan strongly reduces blood pressure (BP) in patients with hypertension and has been shown to have cardioprotective effects. A new ARB, azilsartan, was recently approved and has been shown to provide a more potent 24-h sustained antihypertensive effect than candesartan. However, the molecular interactions of azilsartan with the AT(1) receptor that could explain its strong BP-lowering activity are not yet clear. To address this issue, we examined the binding affinities of ARBs for the AT(1) receptor and their inverse agonist activity toward the production of inositol phosphate (IP), and we constructed docking models for the interactions between ARBs and the receptor. Azilsartan, unlike candesartan, has a unique moiety, a 5-oxo-1,2,4-oxadiazole, in place of a tetrazole ring. Although the results regarding the binding affinities of azilsartan and candesartan demonstrated that these ARBs interact with the same sites in the AT(1) receptor (Tyr(113), Lys(199) and Gln(257)), the hydrogen bonding between the oxadiazole of azilsartan-Gln(257) is stronger than that between the tetrazole of candesartan-Gln(257), according to molecular docking models. An examination of the inhibition of IP production by ARBs using constitutively active mutant receptors indicated that inverse agonist activity required azilsartan-Gln(257) interaction and that azilsartan had a stronger interaction with Gln(257) than candesartan. Thus, we speculate that azilsartan has a unique binding behavior to the AT(1) receptor due to its 5-oxo-1,2,4-oxadiazole moiety and induces stronger inverse agonism. This property of azilsartan may underlie its previously demonstrated superior BP-lowering efficacy compared with candesartan and other ARBs.
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Affiliation(s)
- Shin-ichiro Miura
- Department of Cardiology, Fukuoka University School of Medicine, 7-45-1 Nanakuma, Jonan-ku, Fukuoka, Japan.
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27
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Moitra S, Tirupula KC, Klein-Seetharaman J, Langmead CJ. A minimal ligand binding pocket within a network of correlated mutations identified by multiple sequence and structural analysis of G protein coupled receptors. BMC BIOPHYSICS 2012; 5:13. [PMID: 22748306 PMCID: PMC3478154 DOI: 10.1186/2046-1682-5-13] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Accepted: 06/21/2012] [Indexed: 01/07/2023]
Abstract
Background G protein coupled receptors (GPCRs) are seven helical transmembrane proteins that function as signal transducers. They bind ligands in their extracellular and transmembrane regions and activate cognate G proteins at their intracellular surface at the other side of the membrane. The relay of allosteric communication between the ligand binding site and the distant G protein binding site is poorly understood. In this study, GREMLIN
[1], a recently developed method that identifies networks of co-evolving residues from multiple sequence alignments, was used to identify those that may be involved in communicating the activation signal across the membrane. The GREMLIN-predicted long-range interactions between amino acids were analyzed with respect to the seven GPCR structures that have been crystallized at the time this study was undertaken. Results GREMLIN significantly enriches the edges containing residues that are part of the ligand binding pocket, when compared to a control distribution of edges drawn from a random graph. An analysis of these edges reveals a minimal GPCR binding pocket containing four residues (T1183.33, M2075.42, Y2686.51 and A2927.39). Additionally, of the ten residues predicted to have the most long-range interactions (A1173.32, A2726.55, E1133.28, H2115.46, S186EC2, A2927.39, E1223.37, G902.57, G1143.29 and M2075.42), nine are part of the ligand binding pocket. Conclusions We demonstrate the use of GREMLIN to reveal a network of statistically correlated and functionally important residues in class A GPCRs. GREMLIN identified that ligand binding pocket residues are extensively correlated with distal residues. An analysis of the GREMLIN edges across multiple structures suggests that there may be a minimal binding pocket common to the seven known GPCRs. Further, the activation of rhodopsin involves these long-range interactions between extracellular and intracellular domain residues mediated by the retinal domain.
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Affiliation(s)
- Subhodeep Moitra
- Computer Science Department, Carnegie Mellon University, Gates Hillman Center, 5000 Forbes Avenue, Pittsburgh, PA, USA
| | - Kalyan C Tirupula
- Department of Structural Biology, University of Pittsburgh School of Medicine, Rm. 2051, Biomedical Science Tower 3, 3501 Fifth Avenue, Pittsburgh, PA, USA
| | - Judith Klein-Seetharaman
- Department of Structural Biology, University of Pittsburgh School of Medicine, Rm. 2051, Biomedical Science Tower 3, 3501 Fifth Avenue, Pittsburgh, PA, USA
| | - Christopher James Langmead
- Computer Science Department, Carnegie Mellon University, Gates Hillman Center, 5000 Forbes Avenue, Pittsburgh, PA, USA
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28
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Miura SI, Kiya Y, Hanzawa H, Nakao N, Fujino M, Imaizumi S, Matsuo Y, Yanagisawa H, Koike H, Komuro I, Karnik SS, Saku K. Small molecules with similar structures exhibit agonist, neutral antagonist or inverse agonist activity toward angiotensin II type 1 receptor. PLoS One 2012; 7:e37974. [PMID: 22719858 PMCID: PMC3375280 DOI: 10.1371/journal.pone.0037974] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Accepted: 05/01/2012] [Indexed: 11/29/2022] Open
Abstract
Small differences in the chemical structures of ligands can be responsible for agonism, neutral antagonism or inverse agonism toward a G-protein-coupled receptor (GPCR). Although each ligand may stabilize the receptor conformation in a different way, little is known about the precise conformational differences. We synthesized the angiotensin II type 1 receptor blocker (ARB) olmesartan, R239470 and R794847, which induced inverse agonism, antagonism and agonism, respectively, and then investigated the ligand-specific changes in the receptor conformation with respect to stabilization around transmembrane (TM)3. The results of substituted cysteine accessibility mapping studies support the novel concept that ligand-induced changes in the conformation of TM3 play a role in stabilizing GPCR. Although the agonist-, neutral antagonist and inverse agonist-binding sites in the AT(1) receptor are similar, each ligand induced specific conformational changes in TM3. In addition, all of the experimental data were obtained with functional receptors in a native membrane environment (in situ).
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Affiliation(s)
- Shin-ichiro Miura
- Department of Cardiology, Fukuoka University School of Medicine, Fukuoka, Japan.
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29
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Yasuda N, Akazawa H, Ito K, Shimizu I, Kudo-Sakamoto Y, Yabumoto C, Yano M, Yamamoto R, Ozasa Y, Minamino T, Naito AT, Oka T, Shiojima I, Tamura K, Umemura S, Paradis P, Nemer M, Komuro I. Agonist-Independent Constitutive Activity of Angiotensin II Receptor Promotes Cardiac Remodeling in Mice. Hypertension 2012; 59:627-33. [DOI: 10.1161/hypertensionaha.111.175208] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The angiotensin II (Ang II) type 1 (AT
1
) receptor mainly mediates the physiological and pathological actions of Ang II, but recent studies have suggested that AT
1
receptor inherently shows spontaneous constitutive activity even in the absence of Ang II in culture cells. To elucidate the role of Ang II–independent AT
1
receptor activation in the pathogenesis of cardiac remodeling, we generated transgenic mice overexpressing AT
1
receptor under the control of α-myosin heavy chain promoter in angiotensinogen-knockout background (AT
1
Tg-AgtKO mice). In AT
1
Tg-AgtKO hearts, redistributions of the Gα
q11
subunit into cytosol and phosphorylation of extracellular signal-regulated kinases were significantly increased, compared with angiotensinogen-knockout mice hearts, suggesting that the AT
1
receptor is constitutively activated independent of Ang II. As a consequence, AT
1
Tg-AgtKO mice showed spontaneous systolic dysfunction and chamber dilatation, accompanied by severe interstitial fibrosis. Progression of cardiac remodeling in AT
1
Tg-AgtKO mice was prevented by treatment with candesartan, an inverse agonist for the AT
1
receptor, but not by its derivative candesartan-7H, deficient of inverse agonism attributed to a lack of the carboxyl group at the benzimidazole ring. Our results demonstrate that constitutive activity of the AT
1
receptor under basal conditions contributes to the cardiac remodeling even in the absence of Ang II, when the AT
1
receptor is upregulated in the heart.
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Affiliation(s)
- Noritaka Yasuda
- From the Department of Cardiovascular Science and Medicine (N.Y., K.I., Ip.S., R.Y., Y.O., T.M.), Chiba University Graduate School of Medicine, Chiba, Japan; Departments of Cardiovascular Medicine (H.A, Y.K.-S., C.Y., M.Y., T.O., I.K.) and Cardiovascular Regenerative Medicine (A.T.N., Ic.S.), Osaka University Graduate School of Medicine, Suita, Japan; Department of Medical Science and Cardiorenal Medicine (K.T., S.U.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Lady Davis
| | - Hiroshi Akazawa
- From the Department of Cardiovascular Science and Medicine (N.Y., K.I., Ip.S., R.Y., Y.O., T.M.), Chiba University Graduate School of Medicine, Chiba, Japan; Departments of Cardiovascular Medicine (H.A, Y.K.-S., C.Y., M.Y., T.O., I.K.) and Cardiovascular Regenerative Medicine (A.T.N., Ic.S.), Osaka University Graduate School of Medicine, Suita, Japan; Department of Medical Science and Cardiorenal Medicine (K.T., S.U.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Lady Davis
| | - Kaoru Ito
- From the Department of Cardiovascular Science and Medicine (N.Y., K.I., Ip.S., R.Y., Y.O., T.M.), Chiba University Graduate School of Medicine, Chiba, Japan; Departments of Cardiovascular Medicine (H.A, Y.K.-S., C.Y., M.Y., T.O., I.K.) and Cardiovascular Regenerative Medicine (A.T.N., Ic.S.), Osaka University Graduate School of Medicine, Suita, Japan; Department of Medical Science and Cardiorenal Medicine (K.T., S.U.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Lady Davis
| | - Ippei Shimizu
- From the Department of Cardiovascular Science and Medicine (N.Y., K.I., Ip.S., R.Y., Y.O., T.M.), Chiba University Graduate School of Medicine, Chiba, Japan; Departments of Cardiovascular Medicine (H.A, Y.K.-S., C.Y., M.Y., T.O., I.K.) and Cardiovascular Regenerative Medicine (A.T.N., Ic.S.), Osaka University Graduate School of Medicine, Suita, Japan; Department of Medical Science and Cardiorenal Medicine (K.T., S.U.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Lady Davis
| | - Yoko Kudo-Sakamoto
- From the Department of Cardiovascular Science and Medicine (N.Y., K.I., Ip.S., R.Y., Y.O., T.M.), Chiba University Graduate School of Medicine, Chiba, Japan; Departments of Cardiovascular Medicine (H.A, Y.K.-S., C.Y., M.Y., T.O., I.K.) and Cardiovascular Regenerative Medicine (A.T.N., Ic.S.), Osaka University Graduate School of Medicine, Suita, Japan; Department of Medical Science and Cardiorenal Medicine (K.T., S.U.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Lady Davis
| | - Chizuru Yabumoto
- From the Department of Cardiovascular Science and Medicine (N.Y., K.I., Ip.S., R.Y., Y.O., T.M.), Chiba University Graduate School of Medicine, Chiba, Japan; Departments of Cardiovascular Medicine (H.A, Y.K.-S., C.Y., M.Y., T.O., I.K.) and Cardiovascular Regenerative Medicine (A.T.N., Ic.S.), Osaka University Graduate School of Medicine, Suita, Japan; Department of Medical Science and Cardiorenal Medicine (K.T., S.U.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Lady Davis
| | - Masamichi Yano
- From the Department of Cardiovascular Science and Medicine (N.Y., K.I., Ip.S., R.Y., Y.O., T.M.), Chiba University Graduate School of Medicine, Chiba, Japan; Departments of Cardiovascular Medicine (H.A, Y.K.-S., C.Y., M.Y., T.O., I.K.) and Cardiovascular Regenerative Medicine (A.T.N., Ic.S.), Osaka University Graduate School of Medicine, Suita, Japan; Department of Medical Science and Cardiorenal Medicine (K.T., S.U.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Lady Davis
| | - Rie Yamamoto
- From the Department of Cardiovascular Science and Medicine (N.Y., K.I., Ip.S., R.Y., Y.O., T.M.), Chiba University Graduate School of Medicine, Chiba, Japan; Departments of Cardiovascular Medicine (H.A, Y.K.-S., C.Y., M.Y., T.O., I.K.) and Cardiovascular Regenerative Medicine (A.T.N., Ic.S.), Osaka University Graduate School of Medicine, Suita, Japan; Department of Medical Science and Cardiorenal Medicine (K.T., S.U.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Lady Davis
| | - Yukako Ozasa
- From the Department of Cardiovascular Science and Medicine (N.Y., K.I., Ip.S., R.Y., Y.O., T.M.), Chiba University Graduate School of Medicine, Chiba, Japan; Departments of Cardiovascular Medicine (H.A, Y.K.-S., C.Y., M.Y., T.O., I.K.) and Cardiovascular Regenerative Medicine (A.T.N., Ic.S.), Osaka University Graduate School of Medicine, Suita, Japan; Department of Medical Science and Cardiorenal Medicine (K.T., S.U.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Lady Davis
| | - Tohru Minamino
- From the Department of Cardiovascular Science and Medicine (N.Y., K.I., Ip.S., R.Y., Y.O., T.M.), Chiba University Graduate School of Medicine, Chiba, Japan; Departments of Cardiovascular Medicine (H.A, Y.K.-S., C.Y., M.Y., T.O., I.K.) and Cardiovascular Regenerative Medicine (A.T.N., Ic.S.), Osaka University Graduate School of Medicine, Suita, Japan; Department of Medical Science and Cardiorenal Medicine (K.T., S.U.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Lady Davis
| | - Atsuhiko T. Naito
- From the Department of Cardiovascular Science and Medicine (N.Y., K.I., Ip.S., R.Y., Y.O., T.M.), Chiba University Graduate School of Medicine, Chiba, Japan; Departments of Cardiovascular Medicine (H.A, Y.K.-S., C.Y., M.Y., T.O., I.K.) and Cardiovascular Regenerative Medicine (A.T.N., Ic.S.), Osaka University Graduate School of Medicine, Suita, Japan; Department of Medical Science and Cardiorenal Medicine (K.T., S.U.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Lady Davis
| | - Toru Oka
- From the Department of Cardiovascular Science and Medicine (N.Y., K.I., Ip.S., R.Y., Y.O., T.M.), Chiba University Graduate School of Medicine, Chiba, Japan; Departments of Cardiovascular Medicine (H.A, Y.K.-S., C.Y., M.Y., T.O., I.K.) and Cardiovascular Regenerative Medicine (A.T.N., Ic.S.), Osaka University Graduate School of Medicine, Suita, Japan; Department of Medical Science and Cardiorenal Medicine (K.T., S.U.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Lady Davis
| | - Ichiro Shiojima
- From the Department of Cardiovascular Science and Medicine (N.Y., K.I., Ip.S., R.Y., Y.O., T.M.), Chiba University Graduate School of Medicine, Chiba, Japan; Departments of Cardiovascular Medicine (H.A, Y.K.-S., C.Y., M.Y., T.O., I.K.) and Cardiovascular Regenerative Medicine (A.T.N., Ic.S.), Osaka University Graduate School of Medicine, Suita, Japan; Department of Medical Science and Cardiorenal Medicine (K.T., S.U.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Lady Davis
| | - Kouichi Tamura
- From the Department of Cardiovascular Science and Medicine (N.Y., K.I., Ip.S., R.Y., Y.O., T.M.), Chiba University Graduate School of Medicine, Chiba, Japan; Departments of Cardiovascular Medicine (H.A, Y.K.-S., C.Y., M.Y., T.O., I.K.) and Cardiovascular Regenerative Medicine (A.T.N., Ic.S.), Osaka University Graduate School of Medicine, Suita, Japan; Department of Medical Science and Cardiorenal Medicine (K.T., S.U.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Lady Davis
| | - Satoshi Umemura
- From the Department of Cardiovascular Science and Medicine (N.Y., K.I., Ip.S., R.Y., Y.O., T.M.), Chiba University Graduate School of Medicine, Chiba, Japan; Departments of Cardiovascular Medicine (H.A, Y.K.-S., C.Y., M.Y., T.O., I.K.) and Cardiovascular Regenerative Medicine (A.T.N., Ic.S.), Osaka University Graduate School of Medicine, Suita, Japan; Department of Medical Science and Cardiorenal Medicine (K.T., S.U.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Lady Davis
| | - Pierre Paradis
- From the Department of Cardiovascular Science and Medicine (N.Y., K.I., Ip.S., R.Y., Y.O., T.M.), Chiba University Graduate School of Medicine, Chiba, Japan; Departments of Cardiovascular Medicine (H.A, Y.K.-S., C.Y., M.Y., T.O., I.K.) and Cardiovascular Regenerative Medicine (A.T.N., Ic.S.), Osaka University Graduate School of Medicine, Suita, Japan; Department of Medical Science and Cardiorenal Medicine (K.T., S.U.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Lady Davis
| | - Mona Nemer
- From the Department of Cardiovascular Science and Medicine (N.Y., K.I., Ip.S., R.Y., Y.O., T.M.), Chiba University Graduate School of Medicine, Chiba, Japan; Departments of Cardiovascular Medicine (H.A, Y.K.-S., C.Y., M.Y., T.O., I.K.) and Cardiovascular Regenerative Medicine (A.T.N., Ic.S.), Osaka University Graduate School of Medicine, Suita, Japan; Department of Medical Science and Cardiorenal Medicine (K.T., S.U.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Lady Davis
| | - Issei Komuro
- From the Department of Cardiovascular Science and Medicine (N.Y., K.I., Ip.S., R.Y., Y.O., T.M.), Chiba University Graduate School of Medicine, Chiba, Japan; Departments of Cardiovascular Medicine (H.A, Y.K.-S., C.Y., M.Y., T.O., I.K.) and Cardiovascular Regenerative Medicine (A.T.N., Ic.S.), Osaka University Graduate School of Medicine, Suita, Japan; Department of Medical Science and Cardiorenal Medicine (K.T., S.U.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Lady Davis
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30
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Doi N, Yamakawa N, Matsumoto H, Yamamoto Y, Nagano T, Matsumura N, Horisawa K, Yanagawa H. DNA display selection of peptide ligands for a full-length human G protein-coupled receptor on CHO-K1 cells. PLoS One 2012; 7:e30084. [PMID: 22253889 PMCID: PMC3254644 DOI: 10.1371/journal.pone.0030084] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Accepted: 12/09/2011] [Indexed: 12/25/2022] Open
Abstract
The G protein-coupled receptors (GPCRs), which form the largest group of transmembrane proteins involved in signal transduction, are major targets of currently available drugs. Thus, the search for cognate and surrogate peptide ligands for GPCRs is of both basic and therapeutic interest. Here we describe the application of an in vitro DNA display technology to screening libraries of peptide ligands for full-length GPCRs expressed on whole cells. We used human angiotensin II (Ang II) type-1 receptor (hAT1R) as a model GPCR. Under improved selection conditions using hAT1R-expressing Chinese hamster ovary (CHO)-K1 cells as bait, we confirmed that Ang II gene could be enriched more than 10,000-fold after four rounds of selection. Further, we successfully selected diverse Ang II-like peptides from randomized peptide libraries. The results provide more precise information on the sequence-function relationships of hAT1R ligands than can be obtained by conventional alanine-scanning mutagenesis. Completely in vitro DNA display can overcome the limitations of current display technologies and is expected to prove widely useful for screening diverse libraries of mutant peptide and protein ligands for receptors that can be expressed functionally on the surface of CHO-K1 cells.
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Affiliation(s)
- Nobuhide Doi
- Department of Biosciences and Informatics, Keio University, Yokohama, Japan.
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31
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Kiya Y, Miura SI, Matsuo Y, Karnik SS, Saku K. Abilities of candesartan and other AT(1) receptor blockers to impair angiotensin II-induced AT(1) receptor activation after wash-out. J Renin Angiotensin Aldosterone Syst 2011; 13:76-83. [PMID: 21824992 DOI: 10.1177/1470320311417478] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Angiotensin II (Ang II) binds to Ang II type 1 (AT(1)) receptor and evokes cell signaling, and subsequently stimulates vasoconstriction and cell proliferation, which eventually lead to cardiovascular disease. Since most AT(1) receptor blockers (ARBs) have molecular (differential) effects, we evaluated the specific features of candesartan and compared the abilities of candesartan and other ARBs (olmesartan, telmisartan, valsartan, irbesartan and losartan) to bind to and activate AT(1) receptors using a cell-based wash-out assay. Each ARB blocked Ang II-induced extracellular signal-regulated kinase (ERK) activation and inositol phosphate production to different degrees after wash-out. In addition, a small difference in the molecular structure, i.e. a carboxyl group, between candesartan and candesartan-7H was associated with a difference in the degree of this blocking effect. In addition, interaction between Gln(257) in the AT(1) receptor and the carboxyl group of candesartan may be partially associated with the effect of candesartan after wash-out. Although our findings regarding the molecular effects of ARB are based on basic research, these findings may lead to an exciting new area in the clinical application of ARBs.
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Affiliation(s)
- Yoshihiro Kiya
- Department of Cardiology, Fukuoka University School of Medicine, Jonan-ku, Fukuoka, Japan
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32
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Jones ES, Del Borgo MP, Kirsch JF, Clayton D, Bosnyak S, Welungoda I, Hausler N, Unabia S, Perlmutter P, Thomas WG, Aguilar MI, Widdop RE. A Single β-Amino Acid Substitution to Angiotensin II Confers AT
2
Receptor Selectivity and Vascular Function. Hypertension 2011; 57:570-6. [DOI: 10.1161/hypertensionaha.110.164301] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Emma S. Jones
- From the Department of Pharmacology (E.S.J., J.F.K., S.B., I.W., R.E.W.), Department of Biochemistry and Molecular Biology (M.P.D.B., D.C., S.U., M.-I.A.), and School of Chemistry (N.H., P.P.), Monash University, Clayton, Victoria, Australia; School of Biomedical Sciences (W.G.T.), University of Queensland, Brisbane, Queensland, Australia
| | - Mark P. Del Borgo
- From the Department of Pharmacology (E.S.J., J.F.K., S.B., I.W., R.E.W.), Department of Biochemistry and Molecular Biology (M.P.D.B., D.C., S.U., M.-I.A.), and School of Chemistry (N.H., P.P.), Monash University, Clayton, Victoria, Australia; School of Biomedical Sciences (W.G.T.), University of Queensland, Brisbane, Queensland, Australia
| | - Julian F. Kirsch
- From the Department of Pharmacology (E.S.J., J.F.K., S.B., I.W., R.E.W.), Department of Biochemistry and Molecular Biology (M.P.D.B., D.C., S.U., M.-I.A.), and School of Chemistry (N.H., P.P.), Monash University, Clayton, Victoria, Australia; School of Biomedical Sciences (W.G.T.), University of Queensland, Brisbane, Queensland, Australia
| | - Daniel Clayton
- From the Department of Pharmacology (E.S.J., J.F.K., S.B., I.W., R.E.W.), Department of Biochemistry and Molecular Biology (M.P.D.B., D.C., S.U., M.-I.A.), and School of Chemistry (N.H., P.P.), Monash University, Clayton, Victoria, Australia; School of Biomedical Sciences (W.G.T.), University of Queensland, Brisbane, Queensland, Australia
| | - Sanja Bosnyak
- From the Department of Pharmacology (E.S.J., J.F.K., S.B., I.W., R.E.W.), Department of Biochemistry and Molecular Biology (M.P.D.B., D.C., S.U., M.-I.A.), and School of Chemistry (N.H., P.P.), Monash University, Clayton, Victoria, Australia; School of Biomedical Sciences (W.G.T.), University of Queensland, Brisbane, Queensland, Australia
| | - Iresha Welungoda
- From the Department of Pharmacology (E.S.J., J.F.K., S.B., I.W., R.E.W.), Department of Biochemistry and Molecular Biology (M.P.D.B., D.C., S.U., M.-I.A.), and School of Chemistry (N.H., P.P.), Monash University, Clayton, Victoria, Australia; School of Biomedical Sciences (W.G.T.), University of Queensland, Brisbane, Queensland, Australia
| | - Nicholas Hausler
- From the Department of Pharmacology (E.S.J., J.F.K., S.B., I.W., R.E.W.), Department of Biochemistry and Molecular Biology (M.P.D.B., D.C., S.U., M.-I.A.), and School of Chemistry (N.H., P.P.), Monash University, Clayton, Victoria, Australia; School of Biomedical Sciences (W.G.T.), University of Queensland, Brisbane, Queensland, Australia
| | - Sharon Unabia
- From the Department of Pharmacology (E.S.J., J.F.K., S.B., I.W., R.E.W.), Department of Biochemistry and Molecular Biology (M.P.D.B., D.C., S.U., M.-I.A.), and School of Chemistry (N.H., P.P.), Monash University, Clayton, Victoria, Australia; School of Biomedical Sciences (W.G.T.), University of Queensland, Brisbane, Queensland, Australia
| | - Patrick Perlmutter
- From the Department of Pharmacology (E.S.J., J.F.K., S.B., I.W., R.E.W.), Department of Biochemistry and Molecular Biology (M.P.D.B., D.C., S.U., M.-I.A.), and School of Chemistry (N.H., P.P.), Monash University, Clayton, Victoria, Australia; School of Biomedical Sciences (W.G.T.), University of Queensland, Brisbane, Queensland, Australia
| | - Walter G. Thomas
- From the Department of Pharmacology (E.S.J., J.F.K., S.B., I.W., R.E.W.), Department of Biochemistry and Molecular Biology (M.P.D.B., D.C., S.U., M.-I.A.), and School of Chemistry (N.H., P.P.), Monash University, Clayton, Victoria, Australia; School of Biomedical Sciences (W.G.T.), University of Queensland, Brisbane, Queensland, Australia
| | - Marie-Isabel Aguilar
- From the Department of Pharmacology (E.S.J., J.F.K., S.B., I.W., R.E.W.), Department of Biochemistry and Molecular Biology (M.P.D.B., D.C., S.U., M.-I.A.), and School of Chemistry (N.H., P.P.), Monash University, Clayton, Victoria, Australia; School of Biomedical Sciences (W.G.T.), University of Queensland, Brisbane, Queensland, Australia
| | - Robert E. Widdop
- From the Department of Pharmacology (E.S.J., J.F.K., S.B., I.W., R.E.W.), Department of Biochemistry and Molecular Biology (M.P.D.B., D.C., S.U., M.-I.A.), and School of Chemistry (N.H., P.P.), Monash University, Clayton, Victoria, Australia; School of Biomedical Sciences (W.G.T.), University of Queensland, Brisbane, Queensland, Australia
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A small difference in the molecular structure of angiotensin II receptor blockers induces AT₁ receptor-dependent and -independent beneficial effects. Hypertens Res 2010; 33:1044-52. [PMID: 20668453 DOI: 10.1038/hr.2010.135] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Angiotensin II (Ang II) type 1 (AT₁) receptor blockers (ARBs) induce multiple pharmacological beneficial effects, but not all ARBs have the same effects and the molecular mechanisms underlying their actions are not certain. In this study, irbesartan and losartan were examined because of their different molecular structures (irbesartan has a cyclopentyl group whereas losartan has a chloride group). We analyzed the binding affinity and production of inositol phosphate (IP), monocyte chemoattractant protein-1 (MCP-1) and adiponectin. Compared with losartan, irbesartan showed a significantly higher binding affinity and slower dissociation rate from the AT₁ receptor and a significantly higher degree of inverse agonism and insurmountability toward IP production. These effects of irbesartan were not seen with the AT₁-Y113A mutant receptor. On the basis of the molecular modeling of the ARBs-AT₁ receptor complex and a mutagenesis study, the phenyl group at Tyr(113) in the AT₁ receptor and the cyclopentyl group of irbesartan may form a hydrophobic interaction that is stronger than the losartan-AT₁ receptor interaction. Interestingly, irbesartan inhibited MCP-1 production more strongly than losartan. This effect was mediated by the inhibition of nuclear factor-kappa B activation that was independent of the AT₁ receptor in the human coronary endothelial cells. In addition, irbesartan, but not losartan, induced significant adiponectin production that was mediated by peroxisome proliferator-activated receptor-γ activation in 3T3-L1 adipocytes, and this effect was not mediated by the AT₁ receptor. In conclusion, irbesartan induced greater beneficial effects than losartan due to small differences between their molecular structures, and these differential effects were both dependent on and independent of the AT₁ receptor.
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34
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Miura SI, Karnik SS, Saku K. Review: angiotensin II type 1 receptor blockers: class effects versus molecular effects. J Renin Angiotensin Aldosterone Syst 2010; 12:1-7. [PMID: 20603272 DOI: 10.1177/1470320310370852] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Highly selective angiotensin II (Ang II) type 1 (AT(1)) receptor blockers (ARBs) are now available. The AT(1) receptor is a member of the G protein-coupled receptor (GPCR) superfamily and block the diverse effects of Ang II. Several ARBs are available for clinical use. Most ARBs have common molecular structures (biphenyl-tetrazol and imidazole groups) and it is clear that ARBs have 'class effects'. On the other hand, recent clinical studies have demonstrated that not all ARBs have the same effects, and some benefits conferred by ARBs may not be class effects, and instead may be 'molecular effects'. In addition, each ARB has been clearly shown to have specific molecular effects in basic experimental studies, and these effects may be due to small differences in the molecular structure of each ARB. However, it is controversial whether ARBs have molecular effects in a clinical setting. Although the presence of molecular effects for each ARB based on experimental studies may not directly influence the clinical outcome, this possibility has not been adequately evaluated. This review focuses on the class effects versus molecular effects of ARBs from bench to bedside.
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Affiliation(s)
- Shin-ichiro Miura
- Department of Cardiology, Fukuoka University School of Medicine, Fukuoka, Japan.
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35
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Fillion D, Lemieux G, Basambombo LL, Lavigne P, Guillemette G, Leduc R, Escher E. The amino-terminus of angiotensin II contacts several ectodomains of the angiotensin II receptor AT1. J Med Chem 2010; 53:2063-75. [PMID: 20146480 DOI: 10.1021/jm9015747] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
G protein-coupled receptors (GPCRs) are the largest family of cell surface receptors and major targets for drug development. Herein, we sought to identify the regions of the human angiotensin II (AngII) type 1 (hAT(1)) receptor binding cleft that interact with all positions of the AngII using photoaffinity labeling. We conducted a complete iterative walk-through of the AngII sequence with either p-benzoyl-L-phenylalanine (Bpa) or p-[3-(trifluoromethyl)-3H-diazirin-3-yl]-L-phenylalanine (Tdf) to yield two series of eight photoreactive analogues. Pharmacological properties assessment of these sixteen analogues showed that the CAM receptor has a structure-activity relationship (SAR) more amenable to the amino acid substitutions at positions 1, 2, 3, and 5 of AngII than the WT receptor. Photoaffinity labeling of the CAM receptor with the selected analogues, which exhibit different but complementary photochemical properties, suggested that the AngII amino-terminus resides in a hydrophilic environment and interacts simultaneously with different regions of the hAT(1) receptor, including several ectodomains.
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Affiliation(s)
- Dany Fillion
- Department of Pharmacology, Faculty of Medicine and Health Sciences, Universite de Sherbrooke, Sherbrooke, QC, Canada
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36
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Unal H, Jagannathan R, Bhat MB, Karnik SS. Ligand-specific conformation of extracellular loop-2 in the angiotensin II type 1 receptor. J Biol Chem 2010; 285:16341-50. [PMID: 20299456 DOI: 10.1074/jbc.m109.094870] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The orientation of the second extracellular loop (ECL2) is divergent in G-protein coupled receptor (GPCR) structures determined. This discovery provoked the question, is the ECL2 conformation differentially regulated in the GPCRs that respond to diffusible ligands? We have determined the conformation of the ECL2 of the angiotensin II type 1 receptor by reporter-cysteine accessibility mapping in different receptor states (i.e. empty, agonist-bound and antagonist-bound). We introduced cysteines at each position of ECL2 of an N-terminal epitope-tagged receptor surrogate lacking all non-essential cysteines and then measured reaction of these with a cysteine-reactive biotin probe. The ability of biotinylated mutant receptors to react with a steptavidin-HRP-conjugated antibody was used as the basis for examining differences in accessibility. Two segments of ECL2 were accessible in the empty receptor, indicating an open conformation of ECL2. These segments were inaccessible in the ligand-bound states of the receptor. Using the accessibility constraint, we performed molecular dynamics simulation to predict ECL2 conformation in different states of the receptor. Analysis suggested that a lid conformation similar to that of ECL2 in rhodopsin was induced upon binding both agonist and antagonist, but exposing different accessible segments delimited by the highly conserved disulfide bond. Our study reveals the ability of ECL2 to interact with diffusing ligands and to adopt a ligand-specific lid conformation, thus, slowing down dissociation of ligands when bound. Distinct conformations induced by the bound agonist and the antagonist around the conserved disulfide bond suggest an important role for this disulfide bond in producing different functional states of the receptor.
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Affiliation(s)
- Hamiyet Unal
- Department of Molecular Cardiology, Lerner Research Institute, The Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA
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37
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Akazawa H, Yasuda N, Miura SI, Komuro I. Assessment of Inverse Agonism for the Angiotensin II Type 1 Receptor. Methods Enzymol 2010; 485:25-35. [DOI: 10.1016/b978-0-12-381296-4.00002-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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38
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Molecular mechanisms of the antagonistic action between AT1 and AT2 receptors. Biochem Biophys Res Commun 2009; 391:85-90. [PMID: 19896468 DOI: 10.1016/j.bbrc.2009.11.008] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2009] [Accepted: 11/02/2009] [Indexed: 11/23/2022]
Abstract
Although angiotensin II (Ang II) binds to Ang II type 1 (AT(1)) and type 2 (AT(2)) receptors, AT(1) and AT(2) receptors have antagonistic actions with regard to cell signaling. The molecular mechanisms that underlie this antagonism are not well understood. We examined AT(1) and AT(2) receptor-induced signal cross-talk in the cytoplasm and the importance of the hetero-dimerization of AT(1) receptor with AT(2) receptor on the cell surface. AT(1) and AT(2) receptors showed antagonistic effects toward inositol phosphate production. AT(1) receptors mainly formed homo-dimers, rather than hetero-dimers with AT(2) receptor, on the cell surface as determined by immunoprecipitation, and subsequently induced cell signals. AT(2) receptor mainly formed homo-dimers, rather than hetero-dimers with AT(1) receptor, on the cell surface. The expression levels of homo-dimerized AT(1) receptor or AT(2) receptor on the cell surface did not change after treatment with Ang II, the AT(1) receptor antagonist telmisartan or the AT(2) receptor antagonist PD123319. Finally, AT(1) and AT(2) receptor-induced signals antagonized phospholipase C-beta(3) phosphorylation. In conclusion, Ang II-induced AT(1) receptor signals may be mainly blocked by AT(2) receptor signals through their negative cross-talk in the cytoplasm rather than by the hetero-dimerization of both receptors on the cell surface. The proper balance of the expression levels of AT(1) and AT(2) receptors might be critical for the antagonistic action between these receptors.
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Akazawa H, Yasuda N, Komuro I. Mechanisms and functions of agonist-independent activation in the angiotensin II type 1 receptor. Mol Cell Endocrinol 2009; 302:140-7. [PMID: 19059460 DOI: 10.1016/j.mce.2008.11.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2008] [Revised: 11/06/2008] [Accepted: 11/06/2008] [Indexed: 11/23/2022]
Abstract
The angiotensin II (AngII) type 1 (AT(1)) receptor is a seven-transmembrane G protein-coupled receptor, and is involved in regulating the physiological and pathological process of the cardiovascular system. Systemically and locally generated AngII has agonistic action on AT(1) receptor, but recent studies have demonstrated that AT(1) receptor inherently shows spontaneous activity even in the absence of AngII. Furthermore, mechanical stress can activate AT(1) receptor by inducing conformational switch without the involvement of AngII, and induce cardiac hypertrophy in vivo. These agonist-independent activities of AT(1) receptor can be inhibited by inverse agonists, but not by neutral antagonists. Considerable attention has been directed to molecular mechanisms and clinical implications of agonist-independent AT(1) receptor activation, and inverse agonist activity emerges as an important pharmacological parameter for AT(1) receptor blockers that will improve efficacy and expand therapeutic potentials in cardiovascular medicine.
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Affiliation(s)
- Hiroshi Akazawa
- Division of Cardiovascular Pathophysiology, Chiba University Graduate School of Medicine, Chuo-ku, Chiba, Japan
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40
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Bhuiyan MA, Hossain M, Miura SI, Nakamura T, Ozaki M, Nagatomo T. Constitutively Active Mutant N111G of Angiotensin II Type 1 (AT1) Receptor Induces Homologous Internalization Through Mediation of AT1-Receptor Antagonist. J Pharmacol Sci 2009; 111:227-34. [DOI: 10.1254/jphs.09202fp] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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41
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Aplin M, Bonde MM, Hansen JL. Molecular determinants of angiotensin II type 1 receptor functional selectivity. J Mol Cell Cardiol 2009; 46:15-24. [DOI: 10.1016/j.yjmcc.2008.09.123] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2008] [Revised: 09/09/2008] [Accepted: 09/18/2008] [Indexed: 01/14/2023]
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42
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Essential role of TM V and VI for binding the C-terminal sequences of Des-Arg-kinins. Int Immunopharmacol 2008; 8:282-8. [DOI: 10.1016/j.intimp.2007.09.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2007] [Revised: 08/31/2007] [Accepted: 09/02/2007] [Indexed: 11/20/2022]
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43
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Conformational switch of angiotensin II type 1 receptor underlying mechanical stress-induced activation. EMBO Rep 2008; 9:179-86. [PMID: 18202720 DOI: 10.1038/sj.embor.7401157] [Citation(s) in RCA: 145] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2007] [Revised: 11/27/2007] [Accepted: 11/28/2007] [Indexed: 12/19/2022] Open
Abstract
The angiotensin II type 1 (AT(1)) receptor is a G protein-coupled receptor that has a crucial role in the development of load-induced cardiac hypertrophy. Here, we show that cell stretch leads to activation of the AT(1) receptor, which undergoes an anticlockwise rotation and a shift of transmembrane (TM) 7 into the ligand-binding pocket. As an inverse agonist, candesartan suppressed the stretch-induced helical movement of TM7 through the bindings of the carboxyl group of candesartan to the specific residues of the receptor. A molecular model proposes that the tight binding of candesartan to the AT(1) receptor stabilizes the receptor in the inactive conformation, preventing its shift to the active conformation. Our results show that the AT(1) receptor undergoes a conformational switch that couples mechanical stress-induced activation and inverse agonist-induced inactivation.
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44
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Miura SI, Kiya Y, Kanazawa T, Imaizumi S, Fujino M, Matsuo Y, Karnik SS, Saku K. Differential bonding interactions of inverse agonists of angiotensin II type 1 receptor in stabilizing the inactive state. Mol Endocrinol 2008; 22:139-46. [PMID: 17901125 PMCID: PMC2725753 DOI: 10.1210/me.2007-0312] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2007] [Accepted: 09/20/2007] [Indexed: 01/06/2023] Open
Abstract
Although the sartan family of angiotensin II type 1 (AT(1)) receptor blockers (ARBs), which includes valsartan, olmesartan, and losartan, have a common pharmacophore structure, their effectiveness in therapy differs. Although their efficacy may be related to their binding strength, this notion has changed with a better understanding of the molecular mechanism. Therefore, we hypothesized that each ARB differs with regard to its molecular interactions with AT(1) receptor in inducing inverse agonism. Interactions between valsartan and residues Ser(105), Ser(109), and Lys(199) were important for binding. Valsartan is a strong inverse agonist of constitutive inositol phosphate production by the wild-type and N111G mutant receptors. Substituted cysteine accessibility mapping studies indicated that valsartan, but not losartan, which has only weak inverse agonism, may stabilize the N111G receptor in an inactive state upon binding. In addition, the inverse agonism by valsatan was mostly abolished with S105A/S109A/K199Q substitutions in the N111G background. Molecular modeling suggested that Ser(109) and Lys(199) bind to phenyl and tetrazole groups of valsartan, respectively. Ser(105) is a candidate for binding to the carboxyl group of valsartan. Thus, the most critical interaction for inducing inverse agonism involves transmembrane (TM) V (Lys(199)) of AT(1) receptor although its inverse agonist potency is comparable to olmesartan, which bonds with TM III (Tyr(113)) and TM VI (His(256)). These results provide new insights into improving ARBs and development of new G protein-coupled receptor antagonists.
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Affiliation(s)
- Shin-ichiro Miura
- Department of Cardiology, Fukuoka University School of Medicine, Jonan-Ku, Fukuoka 814-0180, Japan.
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45
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Yasuda N, Akazawa H, Qin Y, Zou Y, Komuro I. A novel mechanism of mechanical stress-induced angiotensin II type 1–receptor activation without the involvement of angiotensin II. Naunyn Schmiedebergs Arch Pharmacol 2007; 377:393-9. [DOI: 10.1007/s00210-007-0215-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2007] [Accepted: 10/31/2007] [Indexed: 01/01/2023]
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46
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Wakisaka O, Takahashi N, Shinohara T, Ooie T, Nakagawa M, Yonemochi H, Hara M, Shimada T, Saikawa T, Yoshimatsu H. Hyperthermia treatment prevents angiotensin II-mediated atrial fibrosis and fibrillation via induction of heat-shock protein 72. J Mol Cell Cardiol 2007; 43:616-26. [PMID: 17884089 DOI: 10.1016/j.yjmcc.2007.08.005] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2007] [Revised: 07/19/2007] [Accepted: 08/02/2007] [Indexed: 12/01/2022]
Abstract
We tested the hypothesis that atrial fibrosis and atrial fibrillation (AF) evoked by angiotensin II (AII) could be prevented by the induction of heat-shock protein 72 (HSP72) by hyperthermia (HT). In cultured atrial fibroblasts isolated from male Sprague-Dawley rats, HT (42 degrees C) was applied for 30 min. AII (100 nmol/L) was added to the medium 8 h later. HT induced the expression of HSP72, which was associated with the attenuation of AII-induced extracellular signal-regulated kinase (ERK1/ERK2) phosphorylation, alpha-smooth muscle actin (alpha-SMA) expression, transforming growth factor-beta(1) secretion, collagen synthesis, and expression of collagen type I and tissue inhibitor of metalloproteinases-1. A small interfering RNA targeting HSP72 abolished these anti-fibrotic effects of HT. In male Sprague-Dawley rats in vivo, an osmotic mini-pump was subcutaneously implanted for continuous infusion of AII (400 ng/kg/min). Whole-body HT (43 degrees C, 20 min) was applied 24 h before and 7, 14, and 21 days after the start of the AII infusion. Repeated HT led to the induction of HSP72 expression, which resulted in an attenuation of AII-induced left atrial fibrosis. In an electrophysiological study using isolated perfused heart, continuous AII caused slowing of interatrial conduction without affecting atrial refractoriness. In AII-treated hearts, extrastimuli from the right atrial appendage resulted in a high incidence of repetitive atrial responses, which were suppressed by treatment with HT. Our results suggest that HT treatment is effective in suppressing AII-mediated atrial fibrosis and AF via induction of HSP72 at least in parts, and is thus expected to be a novel strategy for prevention of AF.
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Affiliation(s)
- Osamu Wakisaka
- Department of Internal Medicine 1, Faculty of Medicine, Oita University, Oita, 1-1 Idaigaoka, Hasama, Oita 879-5593, Japan
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47
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Oliveira L, Costa-Neto CM, Nakaie CR, Schreier S, Shimuta SI, Paiva ACM. The Angiotensin II AT1 Receptor Structure-Activity Correlations in the Light of Rhodopsin Structure. Physiol Rev 2007; 87:565-92. [PMID: 17429042 DOI: 10.1152/physrev.00040.2005] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The most prevalent physiological effects of ANG II, the main product of the renin-angiotensin system, are mediated by the AT1 receptor, a rhodopsin-like AGPCR. Numerous studies of the cardiovascular effects of synthetic peptide analogs allowed a detailed mapping of ANG II's structural requirements for receptor binding and activation, which were complemented by site-directed mutagenesis studies on the AT1 receptor to investigate the role of its structure in ligand binding, signal transduction, phosphorylation, binding to arrestins, internalization, desensitization, tachyphylaxis, and other properties. The knowledge of the high-resolution structure of rhodopsin allowed homology modeling of the AT1 receptor. The models thus built and mutagenesis data indicate that physiological (agonist binding) or constitutive (mutated receptor) activation may involve different degrees of expansion of the receptor's central cavity. Residues in ANG II structure seem to control these conformational changes and to dictate the type of cytosolic event elicited during the activation. 1) Agonist aromatic residues (Phe8 and Tyr4) favor the coupling to G protein, and 2) absence of these residues can favor a mechanism leading directly to receptor internalization via phosphorylation by specific kinases of the receptor's COOH-terminal Ser and Thr residues, arrestin binding, and clathrin-dependent coated-pit vesicles. On the other hand, the NH2-terminal residues of the agonists ANG II and [Sar1]-ANG II were found to bind by two distinct modes to the AT1 receptor extracellular site flanked by the COOH-terminal segments of the EC-3 loop and the NH2-terminal domain. Since the [Sar1]-ligand is the most potent molecule to trigger tachyphylaxis in AT1 receptors, it was suggested that its corresponding binding mode might be associated with this special condition of receptors.
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Affiliation(s)
- Laerte Oliveira
- Department of Biophysics, Escola Paulista de Medicina, Federal University of São Paulo, Brazil.
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48
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Ambühl PM, Tissot AC, Fulurija A, Maurer P, Nussberger J, Sabat R, Nief V, Schellekens C, Sladko K, Roubicek K, Pfister T, Rettenbacher M, Volk HD, Wagner F, Müller P, Jennings GT, Bachmann MF. A vaccine for hypertension based on virus-like particles: preclinical efficacy and phase I safety and immunogenicity. J Hypertens 2007; 25:63-72. [PMID: 17143175 DOI: 10.1097/hjh.0b013e32800ff5d6] [Citation(s) in RCA: 155] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Despite the availability of efficacious drugs, the success of treating hypertension is limited by patients' inconsistent drug intake. Immunization against angiotensin II may offer a valuable alternative to conventional drugs for the treatment of hypertension, because vaccines induce relatively long-lasting effects and do not require daily dosing. Here we describe the preclinical development and the phase I clinical trial testing of a virus-like particle (VLP)-based antihypertensive vaccine. METHODS AND RESULTS An angiotensin II-derived peptide was conjugated to the VLP Qbeta (AngQb). AngQb was highly immunogenic in mice and rats. To test for efficacy, spontaneously hypertensive rats (SHR) were immunized with 400 microg AngQb or VLP alone. Group mean systolic blood pressure (SBP) was reduced by up to 21 mmHg (159 +/- 2 versus 180 +/- 5 mmHg, P < 0.001), and total angiotensin II levels (antibody-bound and free) were increased ninefold (85 +/- 20 versus 9 +/- 1 pmol/l, P = 0.002) compared with VLP controls. SHR treated with the angiotensin-converting enzyme (ACE) inhibitor ramipril (1 mg/kg per day by mouth) reached an SBP of 155 +/- 2 mmHg. Twelve healthy volunteers of a placebo-controlled randomized phase I trial were injected once with 100 microg AngQb. Angiotensin II-specific antibodies were raised in all subjects (100% responder rate) and AngQb was well tolerated. CONCLUSIONS AngQb reduces blood pressure in SHR to levels obtained with an ACE inhibitor, and is immunogenic and well tolerated in humans. Therefore, vaccination against angiotensin II has the potential to become a useful antihypertensive treatment providing long-lasting effects and improving patient compliance.
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Reis RI, Santos EL, Pesquero JB, Oliveira L, Schanstra JP, Bascands JL, Pecher C, Paiva ACM, Costa-Neto CM. Participation of transmembrane proline 82 in angiotensin II AT1 receptor signal transduction. ACTA ACUST UNITED AC 2007; 140:32-6. [PMID: 17239455 DOI: 10.1016/j.regpep.2006.11.028] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2006] [Revised: 06/07/2006] [Accepted: 11/10/2006] [Indexed: 11/20/2022]
Abstract
Most of the classical physiological effects of the octapeptide angiotensin II (AngII) are produced by activating the AT1 receptor which belongs to the G-protein coupled receptor family (GPCR). Peptidic GPCRs may be functionally divided in three regions: (i) extracellular domains involved in ligand binding; (ii) intracellular domains implicated in agonist-induced coupling to G protein and (iii) seven transmembrane domains (TM) involved in signal transduction. The TM regions of such receptors have peculiar characteristics such as the presence of proline residues. In this project we aimed to investigate the participation of two highly conserved proline residues (Pro82 and Pro162), located in TM II and TM IV, respectively, in AT1 receptor signal transduction. Both mutations did not cause major alterations in AngII affinity. Functional assays indicated that the P162A mutant did not influence the signal transduction. On the other hand, a potent deleterious effect of P82A mutation on signal transduction was observed. We believe that the Pro82 residue is crucial to signal transduction, although it is not possible to say yet if this is due to a direct participation or if due to a structural rearrangement of TM II. In this last hypothesis, the removal of proline residue might be correlated to a removal of a kink, which in turn can be involved in the correct positioning of residues involved in signal transduction.
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MESH Headings
- Amino Acid Sequence
- Angiotensin II/metabolism
- Animals
- Binding, Competitive
- COS Cells
- Chlorocebus aethiops
- Computer Simulation
- Models, Biological
- Models, Molecular
- Molecular Sequence Data
- Mutagenesis, Site-Directed/methods
- Mutation
- Proline/chemistry
- Proline/genetics
- Protein Binding
- Rats
- Receptor, Angiotensin, Type 1/chemistry
- Receptor, Angiotensin, Type 1/genetics
- Receptor, Angiotensin, Type 1/metabolism
- Receptors, G-Protein-Coupled/metabolism
- Signal Transduction/genetics
- Signal Transduction/physiology
- Structure-Activity Relationship
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Affiliation(s)
- Rosana I Reis
- Department of Biochemistry and Immunology, Faculty of Medicine of Ribeirão Preto, University of São Paulo, 14049-900 Ribeirão Preto, Brazil
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Szidonya L, Süpeki K, Karip E, Turu G, Várnai P, Clark AJL, Hunyady L. AT1 receptor blocker-insensitive mutant AT1A angiotensin receptors reveal the presence of G protein-independent signaling in C9 cells. Biochem Pharmacol 2007; 73:1582-92. [PMID: 17284329 DOI: 10.1016/j.bcp.2007.01.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2006] [Revised: 12/28/2006] [Accepted: 01/03/2007] [Indexed: 01/01/2023]
Abstract
Although mutant receptors are highly useful to dissect the signal transduction pathways of receptors, they are difficult to study in physiological target tissues, due to the presence of endogenous receptors. To study AT(1) angiotensin receptors in their physiological environment, we constructed a mutant receptor, which differs only from the AT(1A) receptor in its reduced affinity for candesartan, a biphenylimidazole antagonist. We have determined that the conserved S109Y substitution of the rat AT(1A) receptor eliminates its candesartan binding, without exerting any major effect on its angiotensin II and peptide angiotensin receptor antagonist binding, internalization kinetics, beta-arrestin binding, and potency or efficacy of the inositol phosphate response. To demonstrate the usefulness of this mutant receptor in signal transduction studies, we combined it with substitution of the highly conserved DRY sequence with AAY, which abolishes G protein activation. In rat C9 hepatocytes the S109Y receptor caused ERK activation with the same mechanism as the endogenous AT(1) receptor. After combination with the DRY/AAY mutation G protein-independent ERK activation was detected demonstrating that this approach can be used to study the angiotensin II-stimulated signaling pathways in cells endogenously expressing AT(1) receptors.
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Affiliation(s)
- László Szidonya
- Department of Physiology, Semmelweis University, Budapest, Hungary
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