1
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Esteban JJ, Mason JR, Kaminski J, Ramachandran R, Luyt LG. A survey of stapling methods to increase affinity, activity, and stability of ghrelin analogues. RSC Med Chem 2024; 15:254-266. [PMID: 38283230 PMCID: PMC10809362 DOI: 10.1039/d3md00441d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 11/29/2023] [Indexed: 01/30/2024] Open
Abstract
The growth hormone secretagogue receptor (GHSR) is a G protein-coupled receptor which regulates various important physiological and pathophysiological processes in the body such as energy homeostasis, growth hormone secretion and regulation of appetite. As a result, it has been postulated as a potential therapeutic target for the treatment of cancer cachexia and other metabolic disorders, as well as a potential imaging agent target for cancers and cardiovascular diseases. Ghrelin is the primary high affinity endogenous ligand for GHSR and has limited secondary structure in solution, which makes it proteolytically unstable. This inherent instability in ghrelin can be overcome by incorporating helix-inducing staples that stabilize its structure and improve affinity and activity. We present an analysis of different stapling methods at positions 12 and 16 of ghrelin(1-20) analogues with the goal of increasing proteolytic stability and to retain or improve affinity and activity towards the GHSR. Ghrelin(1-20) analogues were modified with a wide range of chemical staples, including a lactam staple, triazole staple, hydrocarbon staple, Glaser staple, and xylene-thioether staple. Once synthesized, the receptor affinity and α-helicity were measured using competitive binding assays and circular dichroism spectroscopy, respectively. Generally, an increase in alpha-helicity using a flexible staple linker led to improved affinity towards GHSR. Ghrelin(1-20) analogues with a lactam, triazole, and hydrocarbon staple resulted in helical analogues with stronger affinity towards GHSR than unstapled ghrelin(1-20), a compound that lacks helical character. Compounds were also investigated for their agonist activity through β-arrestin 1 & 2 recruitment BRET assays and for their metabolic stability through serum stability analysis.
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Affiliation(s)
- Juan J Esteban
- Department of Chemistry, University of Western Ontario 1151 Richmond Street London Ontario N6A 3K7 Canada
| | - Julia R Mason
- Department of Chemistry, University of Western Ontario 1151 Richmond Street London Ontario N6A 3K7 Canada
| | - Jakob Kaminski
- Department of Chemistry, University of Western Ontario 1151 Richmond Street London Ontario N6A 3K7 Canada
| | - Rithwik Ramachandran
- Department of Physiology and Pharmacology, University of Western Ontario 1151 Richmond Street London Ontario N6A 5C1 Canada
| | - Leonard G Luyt
- Department of Chemistry, University of Western Ontario 1151 Richmond Street London Ontario N6A 3K7 Canada
- Departments of Medical Imaging and Oncology, University of Western Ontario 1151 Richmond Street London Ontario N6A 3K7 Canada
- London Regional Cancer Program, Lawson Health Research Institute 800 Commissioners Road East London Ontario N6A 4L6 Canada
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2
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Azmi MB, Sehgal SA, Asif U, Musani S, Abedin MFE, Suri A, Ahmed SDH, Qureshi SA. Genetic insights into obesity: in silico identification of pathogenic SNPs in MBOAT4 gene and their structural molecular dynamics consequences. J Biomol Struct Dyn 2023:1-17. [PMID: 37921712 DOI: 10.1080/07391102.2023.2274970] [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: 07/04/2023] [Accepted: 10/18/2023] [Indexed: 11/04/2023]
Abstract
Membrane Bound O-Acyltransferase Domain-Containing 4 (MBOAT4) protein catalyzes ghrelin acylation, leading to prominent ghrelin activity, hence characterizing its role as an anti-obesity target. We extracted 625 exonic SNPs from the ENSEMBL database and one phenotype-based missense mutation associated with obesity (A46T) from the HGMD (Human Gene Mutation Database). These were differentiated on deleterious missense SNPs of the MBOAT4 gene through MAF (minor allele frequency: <0.01) cut-off criteria in relation to some bioinformatics-based supervised machine learning tools. We found 8 rare-coding and harmful missense SNPs. The consensus classifier (PredictSNP) tool predicted that the SNP (G57S, C: rs561065025) was the most pathogenic. Several trained in silico algorithms have predicted decreased protein stability [ΔΔG (kcal/mol)] function in the presence of these rare-coding pathogenic mutations in the MBOAT4 gene. Then, a stereochemical quality check (i.e. validation and assessment) of the 3D model was performed, followed by a blind cavity docking approach, used to search for druggable cavities and molecular interactions with citrus flavonoids of the Rutaceae family, ranked with energetic estimations. Significant interactions with Phloretin 3',5'-Di-C-Glucoside were also observed at R304, W306, N307, A311, L314 and H338 with (iGEMDOCK: -95.82 kcal/mol and AutoDock: -7.80 kcal/mol). The RMSD values and other variables of MD simulation analyses on this protein further validated its significant interactions with the above flavonoids. The MBOAT4 gene and its molecular interactions could serve as an interventional future anti-obesity target. The current study's findings will benefit future prospects for large population-based studies and drug development, particularly for generating personalized medicine.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Muhammad Bilal Azmi
- Department of Biochemistry, Dow Medical College, Dow University of Health Sciences, Karachi, Pakistan
| | - Sheikh Arslan Sehgal
- Department of Bioinformatics, Institute of Biochemistry, Biotechnology and Bioinformatics, The Islamia University of Bahawalpur, Bahawalpur, Pakistan
| | - Uzma Asif
- Department of Biochemistry, Medicine Program, Batterjee Medical College, Jeddah, Saudi Arabia
| | - Sarah Musani
- Dow Medical College, Dow University of Health Sciences, Karachi, Pakistan
| | | | - Azeema Suri
- Dow Medical College, Dow University of Health Sciences, Karachi, Pakistan
| | - Syed Danish Haseen Ahmed
- Department of Biochemistry, Dow Medical College, Dow University of Health Sciences, Karachi, Pakistan
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3
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Rahman QFA, Jufri NF, Hamid A. Hyperphagia in Prader-Willi syndrome with obesity: From development to pharmacological treatment. Intractable Rare Dis Res 2023; 12:5-12. [PMID: 36873672 PMCID: PMC9976092 DOI: 10.5582/irdr.2022.01127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 02/10/2023] [Accepted: 02/25/2023] [Indexed: 03/03/2023] Open
Abstract
Prader-Willi syndrome (PWS) is a rare genetic disorder due to lack of genes expression inherited from the paternal chromosome 15q11-q13 region usually from paternal deletions, maternal uniparental disomy 15 or imprinting defect. There are two different nutritional stages reported in an individual with PWS; first stage during infancy marked by feeding and growth difficulties and second stage where hyperphagia starts and leads to development of obesity. However, the exact mechanism of hyperphagia development, from having difficulties in feeding during early years to insatiable appetite after they grow is still unknown and is the focused in this review. The keywords used for literature search such as "Prader-Willi syndrome", "hyperphagia", "obesity", and "treatment" were used to create the search strings by using synonyms in order to retrieve the relevant records from PubMed, Scopus and Science Direct. The possible mechanism of hyperphagia can be classed into hormonal abnormalities such as increase in ghrelin and leptin from infancy to adulthood. Low level of hormones was observed in the thyroid, insulin and peptide YY at certain ages. Neuronal abnormalities contributed by Orexin A and brain structure alteration was documented at 4-30 years old. Treatment in the form of drugs such as livoletide, topiramate, and diazoxide could potentially alleviate these abnormalities and make hyperphagia less prominent in PWS. The approaches are important to regulate the hormonal changes and neuronal involvement as potentially controlling hyperphagia and obesity.
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Affiliation(s)
| | - Nurul Farhana Jufri
- Address correspondence to:Nurul Farhana Jufri, Biomedical Science Program, Center for Toxicology and Health Risk Studies, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, Kuala Lumpur 50300, Malaysia. E-mail:
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4
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Bukhari SNA. An insight into the multifunctional role of ghrelin and structure activity relationship studies of ghrelin receptor ligands with clinical trials. Eur J Med Chem 2022; 235:114308. [PMID: 35344905 DOI: 10.1016/j.ejmech.2022.114308] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Revised: 02/06/2022] [Accepted: 03/18/2022] [Indexed: 11/30/2022]
Abstract
Ghrelin is a multifunctional gastrointestinal acylated peptide, primarily synthesized in the stomach and regulates the secretion of growth hormone and energy homeostasis. It plays a central role in modulating the diverse biological, physiological and pathological functions in vertebrates. The synthesis of ghrelin receptor ligands after the finding of growth hormone secretagogue developed from Met-enkephalin led to reveal the endogenous ligand ghrelin and the receptors. Subsequently, many peptides, small molecules and peptidomimetics focusing on the ghrelin receptor, GHS-R1a, were derived. In this review, the key features of ghrelin's structure, forms, its bio-physiological functions, pathological roles and therapeutic potential have been highlighted. A few peptidomimetics and pseudo peptide synthetic perspectives have also been discussed to make ghrelin receptor ligands, clinical trials and their success.
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Affiliation(s)
- Syed Nasir Abbas Bukhari
- Department of Pharmaceutical Chemistry, College of Pharmacy, Jouf University, Sakaka, Aljouf, 2014, Saudi Arabia.
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5
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Davis TR, Pierce MR, Novak SX, Hougland JL. Ghrelin octanoylation by ghrelin O-acyltransferase: protein acylation impacting metabolic and neuroendocrine signalling. Open Biol 2021; 11:210080. [PMID: 34315274 PMCID: PMC8316800 DOI: 10.1098/rsob.210080] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The acylated peptide hormone ghrelin impacts a wide range of physiological processes but is most well known for controlling hunger and metabolic regulation. Ghrelin requires a unique posttranslational modification, serine octanoylation, to bind and activate signalling through its cognate GHS-R1a receptor. Ghrelin acylation is catalysed by ghrelin O-acyltransferase (GOAT), a member of the membrane-bound O-acyltransferase (MBOAT) enzyme family. The ghrelin/GOAT/GHS-R1a system is defined by multiple unique aspects within both protein biochemistry and endocrinology. Ghrelin serves as the only substrate for GOAT within the human proteome and, among the multiple hormones involved in energy homeostasis and metabolism such as insulin and leptin, acts as the only known hormone in circulation that directly stimulates appetite and hunger signalling. Advances in GOAT enzymology, structural modelling and inhibitor development have revolutionized our understanding of this enzyme and offered new tools for investigating ghrelin signalling at the molecular and organismal levels. In this review, we briefly summarize the current state of knowledge regarding ghrelin signalling and ghrelin/GOAT enzymology, discuss the GOAT structural model in the context of recently reported MBOAT enzyme superfamily member structures, and highlight the growing complement of GOAT inhibitors that offer options for both ghrelin signalling studies and therapeutic applications.
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Affiliation(s)
- Tasha R Davis
- Department of Chemistry, Syracuse University, Syracuse, NY 13244 USA
| | - Mariah R Pierce
- Department of Chemistry, Syracuse University, Syracuse, NY 13244 USA
| | - Sadie X Novak
- Department of Chemistry, Syracuse University, Syracuse, NY 13244 USA
| | - James L Hougland
- Department of Chemistry, Syracuse University, Syracuse, NY 13244 USA.,BioInspired Syracuse, Syracuse University, Syracuse, NY 13244 USA
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6
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Montégut L, Lopez-Otin C, Magnan C, Kroemer G. Old Paradoxes and New Opportunities for Appetite Control in Obesity. Trends Endocrinol Metab 2021; 32:264-294. [PMID: 33707095 DOI: 10.1016/j.tem.2021.02.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 02/09/2021] [Accepted: 02/11/2021] [Indexed: 12/13/2022]
Abstract
Human obesity is accompanied by alterations in the blood concentrations of multiple circulating appetite regulators. Paradoxically, most of the appetite-inhibitory hormones are elevated in nonsyndromic obesity, while most of the appetite stimulatory hormones are reduced, perhaps reflecting vain attempts of regulation by inefficient feedback circuitries. In this context, it is important to understand which appetite regulators exhibit a convergent rather than paradoxical behavior and hence are likely to contribute to the maintenance of the obese state. Pharmacological interventions in obesity should preferentially consist of the supplementation of deficient appetite inhibitors or the neutralization of excessive appetite stimulators. Here, we critically analyze the current literature on appetite-regulatory peptide hormones. We propose a short-list of appetite modulators that may constitute the best candidates for therapeutic interventions.
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Affiliation(s)
- Léa Montégut
- Centre de Recherche des Cordeliers, Equipe labellisée par la Ligue Contre le Cancer, Université de Paris, Sorbonne Université, INSERM U1138, Institut Universitaire de France, Paris, France; Metabolomics and Cell Biology Platforms, Institut Gustave Roussy, Villejuif, France
| | - Carlos Lopez-Otin
- Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Instituto Universitario de Oncología del Principado de Asturias (IUOPA), Universidad de Oviedo, 33006, Oviedo, Spain
| | | | - Guido Kroemer
- Centre de Recherche des Cordeliers, Equipe labellisée par la Ligue Contre le Cancer, Université de Paris, Sorbonne Université, INSERM U1138, Institut Universitaire de France, Paris, France; Metabolomics and Cell Biology Platforms, Institut Gustave Roussy, Villejuif, France; Unité de Biologie Fonctionnelle et Adaptative, Sorbonne Paris Cité, CNRS UMR8251, Université Paris Diderot, Paris, France; Pôle de Biologie, Hôpital Européen Georges Pompidou, AP-, HP, Paris, France; Suzhou Institute for Systems Medicine, Chinese Academy of Medical Sciences, Suzhou, China; Karolinska Institute, Department of Women's and Children's Health, Karolinska University Hospital, Stockholm, Sweden.
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7
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Suazo KF, Park KY, Distefano MD. A Not-So-Ancient Grease History: Click Chemistry and Protein Lipid Modifications. Chem Rev 2021; 121:7178-7248. [PMID: 33821625 DOI: 10.1021/acs.chemrev.0c01108] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Protein lipid modification involves the attachment of hydrophobic groups to proteins via ester, thioester, amide, or thioether linkages. In this review, the specific click chemical reactions that have been employed to study protein lipid modification and their use for specific labeling applications are first described. This is followed by an introduction to the different types of protein lipid modifications that occur in biology. Next, the roles of click chemistry in elucidating specific biological features including the identification of lipid-modified proteins, studies of their regulation, and their role in diseases are presented. A description of the use of protein-lipid modifying enzymes for specific labeling applications including protein immobilization, fluorescent labeling, nanostructure assembly, and the construction of protein-drug conjugates is presented next. Concluding remarks and future directions are presented in the final section.
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Affiliation(s)
- Kiall F Suazo
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Keun-Young Park
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Mark D Distefano
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
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8
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Tosti L, Hang Y, Debnath O, Tiesmeyer S, Trefzer T, Steiger K, Ten FW, Lukassen S, Ballke S, Kühl AA, Spieckermann S, Bottino R, Ishaque N, Weichert W, Kim SK, Eils R, Conrad C. Single-Nucleus and In Situ RNA-Sequencing Reveal Cell Topographies in the Human Pancreas. Gastroenterology 2021; 160:1330-1344.e11. [PMID: 33212097 DOI: 10.1053/j.gastro.2020.11.010] [Citation(s) in RCA: 92] [Impact Index Per Article: 30.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 10/30/2020] [Accepted: 11/03/2020] [Indexed: 12/15/2022]
Abstract
BACKGROUND & AIMS Molecular evidence of cellular heterogeneity in the human exocrine pancreas has not been yet established because of the local concentration and cascade of hydrolytic enzymes that can rapidly degrade cells and RNA upon pancreatic resection. We sought to better understand the heterogeneity and cellular composition of the pancreas in neonates and adults in healthy and diseased conditions using single-cell sequencing approaches. METHODS We innovated single-nucleus RNA-sequencing protocols and profiled more than 120,000 cells from pancreata of adult and neonatal human donors. We validated the single-nucleus findings using RNA fluorescence in situ hybridization, in situ sequencing, and computational approaches. RESULTS We created the first comprehensive atlas of human pancreas cells including epithelial and nonepithelial constituents, and uncovered 3 distinct acinar cell types, with possible implications for homeostatic and inflammatory processes of the pancreas. The comparison with neonatal single-nucleus sequencing data showed a different cellular composition of the endocrine tissue, highlighting the tissue dynamics occurring during development. By applying spatial cartography, involving cell proximity mapping through in situ sequencing, we found evidence of specific cell type neighborhoods, dynamic topographies in the endocrine and exocrine pancreas, and principles of morphologic organization of the organ. Furthermore, similar analyses in chronic pancreatitis biopsy samples showed the presence of acinar-REG+ cells, a reciprocal association between macrophages and activated stellate cells, and a new potential role of tuft cells in this disease. CONCLUSIONS Our human pancreas cell atlas can be interrogated to understand pancreatic cell biology and provides a crucial reference set for comparisons with diseased tissue samples to map the cellular foundations of pancreatic diseases.
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Affiliation(s)
- Luca Tosti
- Center for Digital Health, Berlin Institute of Health and Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Yan Hang
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, California; Stanford Diabetes Research Center, Stanford University School of Medicine, Stanford, California
| | - Olivia Debnath
- Center for Digital Health, Berlin Institute of Health and Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Sebastian Tiesmeyer
- Center for Digital Health, Berlin Institute of Health and Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Timo Trefzer
- Center for Digital Health, Berlin Institute of Health and Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Katja Steiger
- Institute of Pathology, Technische Universität München, Munich, Germany
| | - Foo Wei Ten
- Center for Digital Health, Berlin Institute of Health and Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Sören Lukassen
- Center for Digital Health, Berlin Institute of Health and Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Simone Ballke
- Stanford Diabetes Research Center, Stanford University School of Medicine, Stanford, California
| | - Anja A Kühl
- iPATH.Berlin, Berlin Institute of Health and Charité - Universitätsmedizin Berlin, corporate member of Freie Universität, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Simone Spieckermann
- iPATH.Berlin, Berlin Institute of Health and Charité - Universitätsmedizin Berlin, corporate member of Freie Universität, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Rita Bottino
- Institute of Cellular Therapeutics, Allegheny Health Network, Pittsburgh, Pennsylvania
| | - Naveed Ishaque
- Center for Digital Health, Berlin Institute of Health and Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Wilko Weichert
- Institute of Pathology, Technische Universität München, Munich, Germany
| | - Seung K Kim
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, California; Stanford Diabetes Research Center, Stanford University School of Medicine, Stanford, California; Department of Medicine, Endocrinology Division, Stanford University School of Medicine, Stanford, California.
| | - Roland Eils
- Center for Digital Health, Berlin Institute of Health and Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany; Health Data Science Unit, Medical Faculty and BioQuant, University of Heidelberg, Heidelberg, Germany.
| | - Christian Conrad
- Center for Digital Health, Berlin Institute of Health and Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany.
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9
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Song L, Yuan J, Liu Y, Zhang D, Zhang C, Lin Q, Li M, Su K, Li Y, Gao G, Ma R, Dong J. Ghrelin system is involved in improvements in glucose metabolism mediated by hyperbaric oxygen treatment in a streptozotocin‑induced type 1 diabetes mouse model. Mol Med Rep 2020; 22:3767-3776. [PMID: 32901885 PMCID: PMC7533472 DOI: 10.3892/mmr.2020.11481] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 07/28/2020] [Indexed: 12/17/2022] Open
Abstract
Type 1 diabetes mellitus (T1DM) is an autoimmune disorder for which the only effective therapy is insulin replacement. Hyperbaric oxygen (HBO) therapy has demonstrated potential in improving hyperglycemia and as a treatment option for T1DM. Ghrelin and HBO have been previously reported to exert proliferative, anti-apoptotic and anti-inflammatory effects in pancreatic cells. The present study investigated the mechanism underlying HBO- and ghrelin system-mediated regulation of glucose metabolism. Male C57BL/6 mice were intraperitoneally injected with streptozotocin (STZ; 150 mg/kg) to induce T1DM before the diabetic mice were randomly assigned into the T1DM and T1DM + HBO groups. Mice in the T1DM + HBO group received HBO (1 h; 100% oxygen; 2 atmospheres absolute) daily for 2 weeks. Significantly lower blood glucose levels and food intake were observed in mice in the T1DM + HBO group. Following HBO treatment, islet β-cell area were increased whereas those of α-cell were decreased in the pancreas. In addition, greater hepatic glycogen storage in liver was observed, which coincided with higher pancreatic glucose transporter 2 (GLUT2) expression levels and reduced hepatic GLUT2 membrane trafficking. There were also substantially higher total plasma ghrelin concentrations and gastric ghrelin-O-acyl transferase (GOAT) expression levels in mice in the T1DM + HBO group. HBO treatment also abolished reductions in pancreatic GOAT expression levels in T1DM mice. Additionally, hepatic growth hormone secretagogue receptor-1a levels were found to be lower in mice in the T1DM + HBO group compared with those in the T1DM group. These results suggest that HBO administration improved glucose metabolism in a STZ-induced T1DM mouse model. The underlying mechanism involves improved insulin-release, glucose-sensing and regulation of hepatic glycogen storage, an observation that was also likely dependent on the ghrelin signalling system.
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Affiliation(s)
- Limin Song
- Department of Special Medicine, Medical College, Qingdao University, Qingdao, Shandong 266071, P.R. China
| | - Junhua Yuan
- Department of Special Medicine, Medical College, Qingdao University, Qingdao, Shandong 266071, P.R. China
| | - Yuan Liu
- Department of Special Medicine, Medical College, Qingdao University, Qingdao, Shandong 266071, P.R. China
| | - Di Zhang
- Department of Special Medicine, Medical College, Qingdao University, Qingdao, Shandong 266071, P.R. China
| | - Caishun Zhang
- Department of Special Medicine, Medical College, Qingdao University, Qingdao, Shandong 266071, P.R. China
| | - Qian Lin
- Department of Special Medicine, Medical College, Qingdao University, Qingdao, Shandong 266071, P.R. China
| | - Manwen Li
- Department of Special Medicine, Medical College, Qingdao University, Qingdao, Shandong 266071, P.R. China
| | - Kaizhen Su
- Department of Clinical Medicine, Medical College, Qingdao University, Qingdao, Shandong 266071, P.R. China
| | - Yanrun Li
- Department of Clinical Medicine, Medical College, Qingdao University, Qingdao, Shandong 266071, P.R. China
| | - Guangkai Gao
- Department of Hyperbaric Medicine, Hospital of Chinese People's Liberation Army, Qingdao, Shandong 266072, P.R. China
| | - Ruixia Ma
- Department of Nephrology, Affiliated Hospital of Qingdao University, Qingdao, Shandong 266005, P.R. China
| | - Jing Dong
- Department of Special Medicine, Medical College, Qingdao University, Qingdao, Shandong 266071, P.R. China
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10
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Shiimura Y, Horita S, Hamamoto A, Asada H, Hirata K, Tanaka M, Mori K, Uemura T, Kobayashi T, Iwata S, Kojima M. Structure of an antagonist-bound ghrelin receptor reveals possible ghrelin recognition mode. Nat Commun 2020; 11:4160. [PMID: 32814772 PMCID: PMC7438500 DOI: 10.1038/s41467-020-17554-1] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 07/08/2020] [Indexed: 01/17/2023] Open
Abstract
Ghrelin is a gastric peptide hormone with important physiological functions. The unique feature of ghrelin is its Serine 3 acyl-modification, which is essential for ghrelin’s activity. However, it remains to be elucidated why the acyl-modification of ghrelin is necessary for activity. To address these questions, we solved the crystal structure of the ghrelin receptor bound to antagonist. The ligand-binding pocket of the ghrelin receptor is bifurcated by a salt bridge between E124 and R283. A striking feature of the ligand-binding pocket of the ghrelin receptor is a wide gap (crevasse) between the TM6 and TM7 bundles that is rich in hydrophobic amino acids, including a cluster of phenylalanine residues. Mutagenesis analyses suggest that the interaction between the gap structure and the acyl acid moiety of ghrelin may participate in transforming the ghrelin receptor into an active conformation. Ghrelin is a gastric peptide hormone with important physiological functions, including growth hormone release and appetite-stimulating activity. Here, authors solved the crystal structure of the ghrelin receptor bound to antagonist and suggested a possible mechanism of activation by acyl-modified ghrelin.
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Affiliation(s)
- Yuki Shiimura
- Division of Molecular Genetics, Institute of Life Science, Kurume University, Fukuoka, Japan.,Department of Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Shoichiro Horita
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Akie Hamamoto
- Division of Molecular Genetics, Institute of Life Science, Kurume University, Fukuoka, Japan
| | - Hidetsugu Asada
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Kunio Hirata
- RIKEN, SPring-8 Center, Hyogo, Japan.,Japan Science and Technology Agency (JST), Precursory Research for Embryonic Science and Technology (PRESTO), Saitama, Japan
| | - Misuzu Tanaka
- Division of Molecular Genetics, Institute of Life Science, Kurume University, Fukuoka, Japan
| | - Kenji Mori
- Department of Biochemistry, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan
| | - Tomoko Uemura
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Takuya Kobayashi
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - So Iwata
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto, Japan. .,Japan Science and Technology Agency (JST), Precursory Research for Embryonic Science and Technology (PRESTO), Saitama, Japan.
| | - Masayasu Kojima
- Division of Molecular Genetics, Institute of Life Science, Kurume University, Fukuoka, Japan.
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11
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Tan Q, Orsso CE, Deehan EC, Triador L, Field CJ, Tun HM, Han JC, Müller TD, Haqq AM. Current and emerging therapies for managing hyperphagia and obesity in Prader-Willi syndrome: A narrative review. Obes Rev 2020; 21:e12992. [PMID: 31889409 DOI: 10.1111/obr.12992] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 12/07/2019] [Accepted: 12/09/2019] [Indexed: 12/16/2022]
Abstract
In early childhood, individuals with Prader-Willi syndrome (PWS) experience excess weight gain and severe hyperphagia with food compulsivity, which often leads to early onset morbid obesity. Effective treatments for appetite suppression and weight control are currently unavailable for PWS. Our aim to further understand the pathogenesis of PWS led us to carry out a comprehensive search of the current and emerging therapies for managing hyperphagia and extreme weight gain in PWS. A literature search was performed using PubMed and the following keywords: "PWS" AND "therapy" OR "[drug name]"; reference lists, pharmaceutical websites, and the ClinicalTrials.gov registry were also reviewed. Articles presenting data from current standard treatments in PWS and also clinical trials of pharmacological agents in the pipeline were selected. Current standard treatments include dietary restriction/modifications, exercise, and growth hormone replacement, which appear to have limited efficacy for appetite and weight control in patients with PWS. The long-term safety and effectiveness of bariatric surgery in PWS remains unknown. However, many promising pharmacotherapies are in development and, if approved, will bring much needed choices into the PWS pharmacological armamentarium. With the progress that is currently being made in our understanding of PWS, an effective treatment may not be far off.
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Affiliation(s)
- Qiming Tan
- Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada
| | - Camila E Orsso
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada
| | - Edward C Deehan
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada
| | - Lucila Triador
- Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada
| | - Catherine J Field
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada
| | - Hein Min Tun
- HKU-Pasteur Research Pole, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, SAR, China
| | - Joan C Han
- Departments of Pediatrics and Physiology, College of Medicine, University of Tennessee Health Science Center and Children's Foundation Research Institute, Le Bonheur Children's Hospital, Memphis, Tennessee, USA
| | - Timo D Müller
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center at Helmholtz Zentrum München, Neuherberg, Germany.,Department of Pharmacology and Experimental Therapy, Institute of Experimental and Clinical Pharmacology and Toxicology, Eberhard Karls University Hospitals and Clinics, Tübingen, Germany
| | - Andrea M Haqq
- Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada.,Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada
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12
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Raghay K, Akki R, Bensaid D, Errami M. Ghrelin as an anti-inflammatory and protective agent in ischemia/reperfusion injury. Peptides 2020; 124:170226. [PMID: 31786283 DOI: 10.1016/j.peptides.2019.170226] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 11/27/2019] [Accepted: 11/27/2019] [Indexed: 02/06/2023]
Abstract
Ischemia/reperfusion (I/R) continue to be the most frequent cause of damaged tissues. Injured tissues resulted from the first ischemic insult, which is determined by the interruption in the blood supply, followed by subsequent impairment induced by reperfusion. In addition, ischemia-reperfusion injury is mediated by tumor necrosis factor (TNF) and other cytokines that activate complements and proteases responsible for free radical production. However, earlier studies have reported the protective roles of bioactive peptides during ischemia reperfusion injury. In fact, ghrelin is a peptide hormone discovered since 1999 as GH secretagogue and its production was identified in gastric X/A-like endocrine cells in rats and P/D1 type cells in humans. To date, this peptide receives growing attention due to its pleiotropic action in the organism and its role in maintaining energy homeostasis. Ghrelin is also involved in stress responses, assuming a modulatory action on immune pathways. Previous studies have identified many other functions related to an anti-inflammatory role in ischemia reperfusion injury. Under these challenging conditions, studies described acylated and unacylated ghrelin in activation and/or inhibition processes related to ischemia-reperfusion injury. The aim of this article is to provide a minireview about ghrelin mechanisms involved in the proinflammatory response of I/R injury. However, the regulatory processes of ghrelin in this pathologic event are still very limited and warrant further investigation.
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Affiliation(s)
- K Raghay
- Department of Biology, Faculty of Sciences, Abdelmalek Essaadi University, Tetouan, Morocco.
| | - R Akki
- Department of Biology, Faculty of Sciences, Abdelmalek Essaadi University, Tetouan, Morocco.
| | - D Bensaid
- Department of Biology, Faculty of Sciences, Abdelmalek Essaadi University, Tetouan, Morocco.
| | - M Errami
- Department of Biology, Faculty of Sciences, Abdelmalek Essaadi University, Tetouan, Morocco.
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13
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Soleyman-Jahi S, Sadeghi F, Pastaki Khoshbin A, Khani L, Roosta V, Zendehdel K. Attribution of Ghrelin to Cancer; Attempts to Unravel an Apparent Controversy. Front Oncol 2019; 9:1014. [PMID: 31681567 PMCID: PMC6805778 DOI: 10.3389/fonc.2019.01014] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 09/20/2019] [Indexed: 12/21/2022] Open
Abstract
Ghrelin is an endogenous peptide hormone mainly produced in the stomach. It has been known to regulate energy homeostasis, stimulate secretion of growth hormone, and mediate many other physiologic effects. Various effects attributed to ghrelin contribute to many aspects of cancer development and progression. Accordingly, a large body of evidence has emerged about the association of ghrelin with several types of cancer in scales of cell-line, animal, and human studies. However, existing data are controversial. This controversy occurs in two main domains: one is the controversial results in local effects of ghrelin on different types of human cancer cell-lines; the second is the apparent disagreement in the results of in-vitro and clinical studies that investigated ghrelin association to one type of cancer. These inconsistencies have hampered the indications to consider ghrelin as a potential tumor biomarker or therapeutic agent in cancer patients. Previous studies have reviewed different parts of current literature about the ghrelin-cancer relationship. Although they have highlighted these controversial results in various ways, no specific recommendations have been given to address it. In this study, we comprehensively reviewed in-vitro, in-vivo, and clinical studies and attempted to use the following approaches to unravel the inconsistencies detected: (a) to distinguish local and systemic effects of ghrelin in interpreting its summary clinical role in each cancer; (b) scrutinizing factors that regulate local effects of ghrelin and could justify different effects of ghrelin on different cancer cell-lines. These approaches could have notable implications for future in-vitro and clinical studies.
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Affiliation(s)
- Saeed Soleyman-Jahi
- Division of Gastroenterology, School of Medicine, Washington University in St. Louis, St. Louis, MO, United States.,Cancer Immunology Project, Universal Scientific Education and Research Network, St. Louis, MO, United States.,Cancer Research Center, Cancer Institute of Iran, Tehran University of Medical Sciences, Tehran, Iran
| | - Fatemeh Sadeghi
- Cancer Research Center, Cancer Institute of Iran, Tehran University of Medical Sciences, Tehran, Iran.,Cancer Immunology Project, Universal Scientific Education and Research Network, Tehran, Iran.,Department of Immunology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Amin Pastaki Khoshbin
- Cancer Immunology Project, Universal Scientific Education and Research Network, Tehran, Iran.,School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Leila Khani
- Department of Immunology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Venus Roosta
- School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Kazem Zendehdel
- Cancer Research Center, Cancer Institute of Iran, Tehran University of Medical Sciences, Tehran, Iran
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14
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Rasineni K, Kubik JL, Casey CA, Kharbanda KK. Inhibition of Ghrelin Activity by Receptor Antagonist [d-Lys-3] GHRP-6 Attenuates Alcohol-Induced Hepatic Steatosis by Regulating Hepatic Lipid Metabolism. Biomolecules 2019; 9:biom9100517. [PMID: 31546643 PMCID: PMC6843513 DOI: 10.3390/biom9100517] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 09/18/2019] [Accepted: 09/19/2019] [Indexed: 01/13/2023] Open
Abstract
Alcoholic steatosis, characterized by an accumulation of triglycerides in hepatocytes, is one of the earliest pathological changes in the progression of alcoholic liver disease. In our previous study, we showed that alcohol-induced increase in serum ghrelin levels impair insulin secretion from pancreatic β-cells. The consequent reduction in the circulating insulin levels promote adipose-derived fatty acid mobilization to ultimately contribute to hepatic steatosis. In this study, we determined whether inhibition of ghrelin activity in chronic alcohol-fed rats could improve hepatic lipid homeostasis at the pancreas-adipose-liver axis. Adult Wistar rats were fed Lieber-DeCarli control or an ethanol liquid diet for 7 weeks. At 6 weeks, a subset of rats in each group were injected with either saline or ghrelin receptor antagonist, [d-Lys-3] GHRP-6 (DLys; 9 mg/kg body weight) for 5 days and all rats were sacrificed 2 days later. DLys treatment of ethanol rats improved pancreatic insulin secretion, normalized serum insulin levels, and the adipose lipid metabolism, as evidenced by the decreased serum free fatty acids (FFA). DLys treatment of ethanol rats also significantly decreased the circulating FFA uptake, de novo hepatic fatty acid synthesis ultimately attenuating alcoholic steatosis. To summarize, inhibition of ghrelin activity reduced alcoholic steatosis by improving insulin secretion, normalizing serum insulin levels, inhibiting adipose lipolysis, and preventing fatty acid uptake and synthesis in the liver. Our studies provided new insights on the important role of ghrelin in modulating the pancreas-adipose-liver, and promoting adipocyte lipolysis and hepatic steatosis. The findings offer a therapeutic approach of not only preventing alcoholic liver injury but also treating it.
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Affiliation(s)
- Karuna Rasineni
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA.
- Research Service, Veterans' Affairs Nebraska-Western Iowa Health Care System, Omaha, NE 68105, USA.
| | - Jacy L Kubik
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA.
- Research Service, Veterans' Affairs Nebraska-Western Iowa Health Care System, Omaha, NE 68105, USA.
| | - Carol A Casey
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA.
- Research Service, Veterans' Affairs Nebraska-Western Iowa Health Care System, Omaha, NE 68105, USA.
| | - Kusum K Kharbanda
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA.
- Research Service, Veterans' Affairs Nebraska-Western Iowa Health Care System, Omaha, NE 68105, USA.
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15
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Rasineni K, Casey CA, Kharbanda KK. Reply to "Letter to Editor: Chronic alcohol exposure alters circulating insulin and ghrelin levels in hepatic steatosis: a translational research perspective". Am J Physiol Gastrointest Liver Physiol 2019; 317:G361-G362. [PMID: 31461305 PMCID: PMC6774088 DOI: 10.1152/ajpgi.00143.2019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 06/03/2019] [Indexed: 01/31/2023]
Affiliation(s)
- Karuna Rasineni
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, Nebraska
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, Nebraska
| | - Carol A Casey
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, Nebraska
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, Nebraska
| | - Kusum K Kharbanda
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, Nebraska
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, Nebraska
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16
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Campaña MB, Irudayanathan FJ, Davis TR, McGovern-Gooch KR, Loftus R, Ashkar M, Escoffery N, Navarro M, Sieburg MA, Nangia S, Hougland JL. The ghrelin O-acyltransferase structure reveals a catalytic channel for transmembrane hormone acylation. J Biol Chem 2019; 294:14166-14174. [PMID: 31413115 DOI: 10.1074/jbc.ac119.009749] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 08/12/2019] [Indexed: 01/17/2023] Open
Abstract
Integral membrane proteins represent a large and diverse portion of the proteome and are often recalcitrant to purification, impeding studies essential for understanding protein structure and function. By combining co-evolutionary constraints and computational modeling with biochemical validation through site-directed mutagenesis and enzyme activity assays, we demonstrate here a synergistic approach to structurally model purification-resistant topologically complex integral membrane proteins. We report the first structural model of a eukaryotic membrane-bound O-acyltransferase (MBOAT), ghrelin O-acyltransferase (GOAT), which modifies the metabolism-regulating hormone ghrelin. Our structure, generated in the absence of any experimental structural data, revealed an unanticipated strategy for transmembrane protein acylation with catalysis occurring in an internal channel connecting the endoplasmic reticulum lumen and cytoplasm. This finding validated the power of our approach to generate predictive structural models for other experimentally challenging integral membrane proteins. Our results illuminate novel aspects of membrane protein function and represent key steps for advancing structure-guided inhibitor design to target therapeutically important but experimentally intractable membrane proteins.
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Affiliation(s)
- Maria B Campaña
- Department of Chemistry, Syracuse University, Syracuse, New York 13244
| | | | - Tasha R Davis
- Department of Chemistry, Syracuse University, Syracuse, New York 13244
| | | | - Rosemary Loftus
- Department of Chemistry, Syracuse University, Syracuse, New York 13244
| | - Mohammad Ashkar
- Department of Chemistry, Syracuse University, Syracuse, New York 13244
| | - Najae Escoffery
- Department of Chemistry, Syracuse University, Syracuse, New York 13244
| | - Melissa Navarro
- Department of Chemistry, Syracuse University, Syracuse, New York 13244
| | | | - Shikha Nangia
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, New York 13244 .,Syracuse Biomaterials Institute, Syracuse University, Syracuse, New York 13244
| | - James L Hougland
- Department of Chemistry, Syracuse University, Syracuse, New York 13244 .,Syracuse Biomaterials Institute, Syracuse University, Syracuse, New York 13244
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