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Niyonzima YB, Wanjiru DK, Kadokawa H. Exercise-induced muscle hormone "irisin" controls luteinizing hormone and follicle-stimulating hormone secretion by bovine gonadotrophs. Anim Reprod Sci 2024; 266:107516. [PMID: 38823233 DOI: 10.1016/j.anireprosci.2024.107516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Revised: 05/23/2024] [Accepted: 05/27/2024] [Indexed: 06/03/2024]
Abstract
Irisin is a hormone secreted by muscle in response to exercise. The irisin receptor (IrisinR) is a heterodimer of integrin alpha V (ITGAV) and integrin beta 5 (ITGB5) subunits. Since irisin may mediate some beneficial effects of exercise on animal reproduction, we tested the hypothesis that bovine gonadotrophs express IrisinR and irisin stimulates luteinizing hormone (LH) and follicle stimulating hormone (FSH) secretion by gonadotrophs. Reverse transcription polymerase chain reaction was used to detect the mRNA expression of both ITGAV and ITGB5 in the anterior pituitary glands (APs) of post pubertal heifers and mouse gonadotroph cell line "LβT2." Western blotting was used to detect protein expression in bovine APs. Immunofluorescence microscopy, utilizing the same antibody, visualized IrisinR on the plasma membrane of majority of gonadotrophs. We prepared AP cells from healthy postpubertal heifers, cultured them for 3.5 d, and treated them with increasing concentrations (0, 0.01, 0.1, 1, or 10 nM) of irisin for 5 min before either no treatment or gonadotropin-releasing hormone (GnRH) stimulation. After 2 h, media were harvested for LH and FSH assays. Irisin (0.1-10 nM) stimulated basal LH and FSH secretion, and these stimulatory effects were inhibited by the extracellular signal-regulated kinase or SMAD pathway inhibitors. In the presence of GnRH, irisin at 0.01-1 nM stimulated LH and FSH secretion. A higher dose of irisin (10 nM), however, suppressed the GnRH-induced LH and FSH levels. In conclusion, bovine gonadotrophs expressed IrisinR, and irisin controlled LH and FSH secretion from bovine gonadotrophs.
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Affiliation(s)
- Yvan Bienvenu Niyonzima
- Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi-shi, Yamaguchi-ken 1677-1, Japan
| | - Denis Karani Wanjiru
- Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi-shi, Yamaguchi-ken 1677-1, Japan
| | - Hiroya Kadokawa
- Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi-shi, Yamaguchi-ken 1677-1, Japan.
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Radomsky T, Anderson RC, Millar RP, Newton CL. Restoring function to inactivating G protein-coupled receptor variants in the hypothalamic-pituitary-gonadal axis 1. J Neuroendocrinol 2024:e13418. [PMID: 38852954 DOI: 10.1111/jne.13418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 03/30/2024] [Accepted: 05/15/2024] [Indexed: 06/11/2024]
Abstract
G protein-coupled receptors (GPCRs) are central to the functioning of the hypothalamic-pituitary-gonadal axis (HPG axis) and include the rhodopsin-like GPCR family members, neurokinin 3 receptor, kappa-opioid receptor, kisspeptin 1 receptor, gonadotropin-releasing hormone receptor, and the gonadotropin receptors, luteinizing hormone/choriogonadotropin receptor and follicle-stimulating hormone receptor. Unsurprisingly, inactivating variants of these receptors have been implicated in a spectrum of reproductive phenotypes, including failure to undergo puberty, and infertility. Clinical induction of puberty in patients harbouring such variants is possible, but restoration of fertility is not always a realisable outcome, particularly for those patients suffering from primary hypogonadism. Thus, novel pharmaceuticals and/or a fundamental change in approach to treating these patients are required. The increasing wealth of data describing the effects of coding-region genetic variants on GPCR function has highlighted that the majority appear to be dysfunctional as a result of misfolding of the encoded receptor protein, which, in turn, results in impaired receptor trafficking through the secretory pathway to the cell surface. As such, these intracellularly retained receptors may be amenable to 'rescue' using a pharmacological chaperone (PC)-based approach. PCs are small, cell permeant molecules hypothesised to interact with misfolded intracellularly retained proteins, stabilising their folding and promoting their trafficking through the secretory pathway. In support of the use of this approach as a viable therapeutic option, it has been observed that many rescued variant GPCRs retain at least a degree of functionality when 'rescued' to the cell surface. In this review, we examine the GPCR PC research landscape, focussing on the rescue of inactivating variant GPCRs with important roles in the HPG axis, and describe what is known regarding the mechanisms by which PCs restore trafficking and function. We also discuss some of the merits and obstacles associated with taking this approach forward into a clinical setting.
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Affiliation(s)
- Tarryn Radomsky
- Centre for Neuroendocrinology, Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Ross C Anderson
- Centre for Neuroendocrinology, Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Robert P Millar
- Centre for Neuroendocrinology, Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
- Deanery of Biomedical Sciences, University of Edinburgh, Edinburgh, UK
- Faculty of Health Sciences, Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa
- School of Medicine, University of St Andrews, St Andrews, UK
| | - Claire L Newton
- Centre for Neuroendocrinology, Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
- Deanery of Biomedical Sciences, University of Edinburgh, Edinburgh, UK
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Eiden LE, Hernández VS, Jiang SZ, Zhang L. Neuropeptides and small-molecule amine transmitters: cooperative signaling in the nervous system. Cell Mol Life Sci 2022; 79:492. [PMID: 35997826 PMCID: PMC11072502 DOI: 10.1007/s00018-022-04451-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 06/15/2022] [Accepted: 06/23/2022] [Indexed: 12/17/2022]
Abstract
Neuropeptides are expressed in cell-specific patterns throughout mammalian brain. Neuropeptide gene expression has been useful for clustering neurons by phenotype, based on single-cell transcriptomics, and for defining specific functional circuits throughout the brain. How neuropeptides function as first messengers in inter-neuronal communication, in cooperation with classical small-molecule amine transmitters (SMATs) is a current topic of systems neurobiology. Questions include how neuropeptides and SMATs cooperate in neurotransmission at the molecular, cellular and circuit levels; whether neuropeptides and SMATs always co-exist in neurons; where neuropeptides and SMATs are stored in the neuron, released from the neuron and acting, and at which receptors, after release; and how neuropeptides affect 'classical' transmitter function, both directly upon co-release, and indirectly, via long-term regulation of gene transcription and neuronal plasticity. Here, we review an extensive body of data about the distribution of neuropeptides and their receptors, their actions after neuronal release, and their function based on pharmacological and genetic loss- and gain-of-function experiments, that addresses these questions, fundamental to understanding brain function, and development of neuropeptide-based, and potentially combinatorial peptide/SMAT-based, neurotherapeutics.
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Affiliation(s)
- Lee E Eiden
- Section On Molecular Neuroscience, National Institute of Mental Health, Intramural Research Program, National Institutes of Health, 49 Convent Drive, Room 5A38, Bethesda, MD, 20892, USA.
| | - Vito S Hernández
- Department of Physiology, School of Medicine, National Autonomous University of Mexico, Mexico City, Mexico
| | - Sunny Z Jiang
- Section On Molecular Neuroscience, National Institute of Mental Health, Intramural Research Program, National Institutes of Health, 49 Convent Drive, Room 5A38, Bethesda, MD, 20892, USA
| | - Limei Zhang
- Department of Physiology, School of Medicine, National Autonomous University of Mexico, Mexico City, Mexico.
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Panknin O, Wagenfeld A, Bone W, Bender E, Nowak-Reppel K, Fernández-Montalván AE, Nubbemeyer R, Bäurle S, Ring S, Schmees N, Prien O, Schäfer M, Friedrich C, Zollner TM, Steinmeyer A, Mueller T, Langer G. Discovery and Characterization of BAY 1214784, an Orally Available Spiroindoline Derivative Acting as a Potent and Selective Antagonist of the Human Gonadotropin-Releasing Hormone Receptor as Proven in a First-In-Human Study in Postmenopausal Women. J Med Chem 2020; 63:11854-11881. [PMID: 32960053 DOI: 10.1021/acs.jmedchem.0c01076] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The growth of uterine fibroids is sex hormone-dependent and commonly associated with highly incapacitating symptoms. Most treatment options consist of the control of these hormonal effects, ultimately blocking proliferative estrogen signaling (i.e., oral contraceptives/antagonization of human gonadotropin-releasing hormone receptor [hGnRH-R] activity). Full hGnRH-R blockade, however, results in menopausal symptoms and affects bone mineralization, thus limiting treatment duration or demanding estrogen add-back approaches. To overcome such issues, we aimed to identify novel, small-molecule hGnRH-R antagonists. This led to the discovery of compound BAY 1214784, an orally available, potent, and selective hGnRH-R antagonist. Altering the geminal dimethylindoline core of the initial hit compound to a spiroindoline system significantly improved GnRH-R antagonist potencies across several species, mandatory for a successful compound optimization in vivo. In a first-in-human study in postmenopausal women, once daily treatment with BAY 1214784 effectively lowered plasma luteinizing hormone levels by up to 49%, at the same time being associated with low pharmacokinetic variability and good tolerability.
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Affiliation(s)
- Olaf Panknin
- Research & Development, Pharmaceuticals, Bayer AG, Müllerstrasse 170, 13342 Berlin, Germany
| | - Andrea Wagenfeld
- Research & Development, Pharmaceuticals, Bayer AG, Müllerstrasse 170, 13342 Berlin, Germany
| | - Wilhelm Bone
- Research & Development, Pharmaceuticals, Bayer AG, Müllerstrasse 170, 13342 Berlin, Germany
| | - Eckhard Bender
- Research & Development, Pharmaceuticals, Bayer AG, Aprather Weg 18a, 42113 Wuppertal, Germany
| | - Katrin Nowak-Reppel
- Research & Development, Pharmaceuticals, Bayer AG, Müllerstrasse 170, 13342 Berlin, Germany
| | | | - Reinhard Nubbemeyer
- Research & Development, Pharmaceuticals, Bayer AG, Müllerstrasse 170, 13342 Berlin, Germany
| | - Stefan Bäurle
- Research & Development, Pharmaceuticals, Bayer AG, Müllerstrasse 170, 13342 Berlin, Germany
| | - Sven Ring
- Research & Development, Pharmaceuticals, Bayer AG, Müllerstrasse 170, 13342 Berlin, Germany
| | - Norbert Schmees
- Research & Development, Pharmaceuticals, Bayer AG, Müllerstrasse 170, 13342 Berlin, Germany
| | - Olaf Prien
- Research & Development, Pharmaceuticals, Bayer AG, Müllerstrasse 170, 13342 Berlin, Germany
| | - Martina Schäfer
- Research & Development, Pharmaceuticals, Bayer AG, Müllerstrasse 170, 13342 Berlin, Germany
| | - Christian Friedrich
- Research & Development, Pharmaceuticals, Bayer AG, Müllerstrasse 170, 13342 Berlin, Germany
| | - Thomas M Zollner
- Research & Development, Pharmaceuticals, Bayer AG, Müllerstrasse 170, 13342 Berlin, Germany
| | - Andreas Steinmeyer
- Research & Development, Pharmaceuticals, Bayer AG, Müllerstrasse 170, 13342 Berlin, Germany
| | - Thomas Mueller
- Research & Development, Pharmaceuticals, Bayer AG, Aprather Weg 18a, 42113 Wuppertal, Germany
| | - Gernot Langer
- Research & Development, Pharmaceuticals, Bayer AG, Müllerstrasse 170, 13342 Berlin, Germany
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Murányi J, Varga A, Gyulavári P, Pénzes K, Németh CE, Csala M, Pethő L, Csámpai A, Halmos G, Peták I, Vályi-Nagy I. Novel Crizotinib-GnRH Conjugates Revealed the Significance of Lysosomal Trapping in GnRH-Based Drug Delivery Systems. Int J Mol Sci 2019; 20:ijms20225590. [PMID: 31717403 PMCID: PMC6888004 DOI: 10.3390/ijms20225590] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 11/06/2019] [Indexed: 12/11/2022] Open
Abstract
Several promising anti-cancer drug–GnRH (gonadotropin-releasing hormone) conjugates have been developed in the last two decades, although none of them have been approved for clinical use yet. Crizotinib is an effective multi-target kinase inhibitor, approved against anaplastic lymphoma kinase (ALK)- or ROS proto-oncogene 1 (ROS-1)-positive non-small cell lung carcinoma (NSCLC); however, its application is accompanied by serious side effects. In order to deliver crizotinib selectively into the tumor cells, we synthesized novel crizotinib analogues and conjugated them to a [d-Lys6]–GnRH-I targeting peptide. Our most prominent crizotinib–GnRH conjugates, the amide-bond-containing [d-Lys6(crizotinib*)]–GnRH-I and the ester-bond-containing [d-Lys6(MJ55*)]–GnRH-I, were able to bind to GnRH-receptor (GnRHR) and exert a potent c-Met kinase inhibitory effect. The efficacy of compounds was tested on the MET-amplified and GnRHR-expressing EBC-1 NSCLC cells. In vitro pharmacological profiling led to the conclusion that that crizotinib–GnRH conjugates are transported directly into lysosomes, where the membrane permeability of crizotinib is diminished. As a consequence of GnRHR-mediated endocytosis, GnRH-conjugated crizotinib bypasses its molecular targets—the ATP-binding site of RTKs— and is sequestered in the lysosomes. These results explained the lower efficacy of crizotinib–GnRH conjugates in EBC-1 cells, and led to the conclusion that drug escape from the lysosomes is a major challenge in the development of clinically relevant anti-cancer drug–GnRH conjugates.
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Affiliation(s)
- József Murányi
- MTA-SE Pathobiochemistry Research Group, Tűzoltó St. 37-47, H1094 Budapest, Hungary; (A.V.); (P.G.); (K.P.)
- Department of Medical Chemistry, Molecular Biology and Pathobiochemistry, Semmelweis University, H1094 Budapest, Hungary; (C.E.N.); (M.C.)
- Correspondence:
| | - Attila Varga
- MTA-SE Pathobiochemistry Research Group, Tűzoltó St. 37-47, H1094 Budapest, Hungary; (A.V.); (P.G.); (K.P.)
| | - Pál Gyulavári
- MTA-SE Pathobiochemistry Research Group, Tűzoltó St. 37-47, H1094 Budapest, Hungary; (A.V.); (P.G.); (K.P.)
| | - Kinga Pénzes
- MTA-SE Pathobiochemistry Research Group, Tűzoltó St. 37-47, H1094 Budapest, Hungary; (A.V.); (P.G.); (K.P.)
| | - Csilla E. Németh
- Department of Medical Chemistry, Molecular Biology and Pathobiochemistry, Semmelweis University, H1094 Budapest, Hungary; (C.E.N.); (M.C.)
| | - Miklós Csala
- Department of Medical Chemistry, Molecular Biology and Pathobiochemistry, Semmelweis University, H1094 Budapest, Hungary; (C.E.N.); (M.C.)
| | - Lilla Pethő
- MTA-ELTE Research Group of Peptide Chemistry, Eötvös Loránd University, H1117 Budapest, Hungary
| | - Antal Csámpai
- Institute of Chemistry, Eötvös Loránd University, H1117 Budapest, Hungary;
| | - Gábor Halmos
- Department of Biopharmacy, Faculty of Pharmacy, University of Debrecen, H4032 Debrecen, Hungary;
| | - István Peták
- Oncompass Medicine Hungary Ltd., H1024 Budapest, Hungary;
| | - István Vályi-Nagy
- Central Hospital of Southern Pest National Institute of Hematology and Infectious Diseases, H1097 Budapest, Hungary;
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Kaprara A, Huhtaniemi IT. The hypothalamus-pituitary-gonad axis: Tales of mice and men. Metabolism 2018; 86:3-17. [PMID: 29223677 DOI: 10.1016/j.metabol.2017.11.018] [Citation(s) in RCA: 166] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Revised: 11/28/2017] [Accepted: 11/29/2017] [Indexed: 02/06/2023]
Abstract
Reproduction is controlled by the hypothalamic-pituitary-gonadal (HPG) axis. Gonadotropin-releasing hormone (GnRH) neurons play a central role in this axis through production of GnRH, which binds to a membrane receptor on pituitary gonadotrophs and stimulates the biosynthesis and secretion of follicle-stimulating hormone (FSH) and luteinizing hormone (LH). Multiple factors affect GnRH neuron migration, GnRH gene expression, GnRH pulse generator, GnRH secretion, GnRH receptor expression, and gonadotropin synthesis and release. Among them anosmin is involved in the guidance of the GnRH neuron migration, and a loss-of-function mutation in its gene leads to a failure of their migration from the olfactory placode to the hypothalamus, with consequent anosmic hypogonadotropic hypogonadism (Kallmann syndrome). There are also cases of hypogonadotropic hypogonadim with normal sense of smell, due to mutations of other genes. Another protein, kisspeptin plays a crucial role in the regulation of GnRH pulse generator and the pubertal development. GnRH is the main hypothalamic regulator of the release of gonadotropins. Finally, FSH and LH are the essential hormonal regulators of testicular functions, acting through their receptors in Sertoli and Leydig cells, respectively. The main features of the male HPG axis will be described in this review.
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Affiliation(s)
- Athina Kaprara
- Unit of Reproductive Endocrinology, Medical School, Aristotle University of Thessaloniki, Greece.
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Chang JP, Pemberton JG. Comparative aspects of GnRH-Stimulated signal transduction in the vertebrate pituitary - Contributions from teleost model systems. Mol Cell Endocrinol 2018; 463:142-167. [PMID: 28587765 DOI: 10.1016/j.mce.2017.06.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 05/31/2017] [Accepted: 06/01/2017] [Indexed: 02/07/2023]
Abstract
Gonadotropin-releasing hormone (GnRH) is a major regulator of reproduction through actions on pituitary gonadotropin release and synthesis. Although it is often thought that pituitary cells are exposed to only one GnRH, multiple GnRH forms are delivered to the pituitary of teleost fishes; interestingly this can include the cGnRH-II form usually thought to be non-hypophysiotropic. GnRHs can regulate other pituitary cell-types, both directly as well as indirectly, and multiple GnRH receptors (GnRHRs) may also be expressed in the pituitary, and even within a single pituitary cell-type. Literature on the differential actions of native GnRH isoforms in primary pituitary cells is largely derived from teleost fishes. This review will outline the diversity and complexity of GnRH-GnRHR signal transduction found within vertebrate gonadotropes as well as extra-gonadotropic sites with special emphasis on comparative studies from fish models. The implications that GnRHR transduction mechanisms are GnRH isoform-, function-, and cell-specific are also discussed.
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Affiliation(s)
- John P Chang
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada.
| | - Joshua G Pemberton
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada.
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Abstract
Gonadotropin-releasing hormone (GnRH) acts via G-protein coupled receptors on pituitary gonadotropes. These are Gq-coupled receptors that mediate acute effects of GnRH on the exocytotic secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), as well as the chronic regulation of their synthesis. FSH and LH control steroidogenesis and gametogenesis in the gonads so GnRH mediates control of reproduction by the central nervous system. GnRH is secreted in short pulses and the effects of GnRH on its target cells are dependent on the dynamics of these pulses. Here we provide a brief overview of the signaling network activated by GnRH with emphasis on the use of high content imaging for their examination. We also describe computational approaches that we have used to simulate GnRH signaling in order to explore dynamics, noise, and information transfer in this system.
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Nederpelt I, Bunnik J, IJzerman AP, Heitman LH. Kinetic Profile of Neuropeptide–Receptor Interactions. Trends Neurosci 2016; 39:830-839. [DOI: 10.1016/j.tins.2016.09.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 09/26/2016] [Accepted: 09/27/2016] [Indexed: 01/18/2023]
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Williams BL, Akazome Y, Oka Y, Eisthen HL. Dynamic evolution of the GnRH receptor gene family in vertebrates. BMC Evol Biol 2014; 14:215. [PMID: 25344287 PMCID: PMC4232701 DOI: 10.1186/s12862-014-0215-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Accepted: 09/25/2014] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Elucidating the mechanisms underlying coevolution of ligands and receptors is an important challenge in molecular evolutionary biology. Peptide hormones and their receptors are excellent models for such efforts, given the relative ease of examining evolutionary changes in genes encoding for both molecules. Most vertebrates possess multiple genes for both the decapeptide gonadotropin releasing hormone (GnRH) and for the GnRH receptor. The evolutionary history of the receptor family, including ancestral copy number and timing of duplications and deletions, has been the subject of controversy. RESULTS We report here for the first time sequences of three distinct GnRH receptor genes in salamanders (axolotls, Ambystoma mexicanum), which are orthologous to three GnRH receptors from ranid frogs. To understand the origin of these genes within the larger evolutionary context of the gene family, we performed phylogenetic analyses and probabilistic protein homology searches of GnRH receptor genes in vertebrates and their near relatives. Our analyses revealed four points that alter previous views about the evolution of the GnRH receptor gene family. First, the "mammalian" pituitary type GnRH receptor, which is the sole GnRH receptor in humans and previously presumed to be highly derived because it lacks the cytoplasmic C-terminal domain typical of most G-protein coupled receptors, is actually an ancient gene that originated in the common ancestor of jawed vertebrates (Gnathostomata). Second, unlike previous studies, we classify vertebrate GnRH receptors into five subfamilies. Third, the order of subfamily origins is the inverse of previous proposed models. Fourth, the number of GnRH receptor genes has been dynamic in vertebrates and their ancestors, with multiple duplications and losses. CONCLUSION Our results provide a novel evolutionary framework for generating hypotheses concerning the functional importance of structural characteristics of vertebrate GnRH receptors. We show that five subfamilies of vertebrate GnRH receptors evolved early in the vertebrate phylogeny, followed by several independent instances of gene loss. Chief among cases of gene loss are humans, best described as degenerate with respect to GnRH receptors because we retain only a single, ancient gene.
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Ulloa-Aguirre A, Michael Conn P. Pharmacoperones: a new therapeutic approach for diseases caused by misfolded G protein-coupled receptors. ACTA ACUST UNITED AC 2012; 5:13-24. [PMID: 22074574 DOI: 10.2174/187221411794351851] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Accepted: 11/13/2010] [Indexed: 01/10/2023]
Abstract
G Protein-coupled receptors (GPCRs) are cell membrane proteins that recognize specific chemical signals such as drugs and hormones and transduce these signals into cellular responses by activating G-proteins. As is the case for all newly synthesized proteins, GPCRs are subjected to conformational scrutiny at the endoplasmic reticulum prior to processing and trafficking to the cell surface membrane. Because of this stringent quality control screening mechanism, mutations that result in protein misfolding frequently lead to retention in the endoplasmic reticulum, aggregation or other misrouting and, eventually, to disease. This article reviews some patents and new therapeutic opportunities based on the misfolding and retention of otherwise functional GPCRs that represent promising approaches to correct conformational abnormalities leading to distinct disease states.
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Affiliation(s)
- Alfredo Ulloa-Aguirre
- Research Unit in Reproductive Medicine, Hospital de Ginecobstetricia Luis Castelazo Ayala, Instituto Mexicano del Seguro Social, Av. Rio Magdalena 289, 60. piso, Col. Tizapan San Angel, C.P. 01090, Mexico D.F., Mexico.
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Lawrence AJ, Heinz A. Imaging - the interface with pharmacology: looking to the future. Br J Pharmacol 2011; 163:1563-4. [DOI: 10.1111/j.1476-5381.2011.01294.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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Conn PM, Ulloa-Aguirre A. Pharmacological chaperones for misfolded gonadotropin-releasing hormone receptors. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2011; 62:109-41. [PMID: 21907908 DOI: 10.1016/b978-0-12-385952-5.00008-7] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Structural alterations provoked by mutations or genetic variations in the gene sequence of G protein-coupled receptors (GPCRs) may lead to abnormal function of the receptor molecule. Frequently, this leads to disease. While some mutations lead to changes in domains involved in agonist binding, receptor activation, or coupling to effectors, others may cause misfolding and lead to retention/degradation of the protein molecule by the quality control system of the cell. Several strategies, including genetic, chemical, and pharmacological approaches, have been shown to rescue function of trafficking-defective misfolded GPCRs. Among these, pharmacological strategies offer the most promising therapeutic tool to promote proper trafficking of misfolded proteins to the plasma membrane (PM). Pharmacological chaperones or "pharmacoperones" are small compounds that permeate the PM, enter cells, and bind selectively to misfolded proteins and correct folding allowing routing of the target protein to the PM, where the receptor may bind and respond to agonist stimulation. In this review, we describe new therapeutic opportunities based on mislocalization of otherwise functional human gonadotropin-releasing hormone receptors. This particular receptor is highly sensitive to single changes in chemical charge, and its intracellular traffic is delicately balanced between expression at the PM or retention/degradation in the endoplasmic reticulum; it is, therefore, a particularly instructive model to understand both the protein routing and the molecular mechanisms, whereby pharmacoperones rescue misfolded intermediates or conformationally defective receptors.
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Affiliation(s)
- P Michael Conn
- Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, Oregon, USA
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