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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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Hassan HA, Essawi ML, Mekkawy MK, Mazen I. Novel mutations of the LHCGR gene in two families with 46,XY DSD causing Leydig cell hypoplasia I. Hormones (Athens) 2020; 19:573-579. [PMID: 32666356 DOI: 10.1007/s42000-020-00226-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 06/21/2020] [Indexed: 10/23/2022]
Abstract
PURPOSE Leydig cell hypoplasia is a rare autosomal recessive 46,XY disorder of sexual development (DSD). It is caused by homozygous or compound heterozygous inactivating mutations in the human luteinizing hormone/chorionic gonadotropin hormone receptor (LHCGR) gene. In Leydig cell hypoplasia type I, patients are characterized by predominantly female external genitalia, which usually go unrecognized until the age of puberty. METHODS This study reports three patients descending from two unrelated families. We performed clinical, hormonal, histopathological, molecular, and bioinformatics studies for the studied cases. RESULTS All investigations suggested 46,XY DSD and Leydig cell hypoplasia. Molecular analysis showed two novel homozygous inactivating mutations (p.Glu148Ter and p.Leu104Pro) within the extracellular domain of the LHCGR gene. CONCLUSION Although the mutations of the LHCGR gene are distributed heterogeneously, without hotspot or recurrent mutations, about one fifth of the reported mutations worldwide have been detected in Arab patients. This is probably due to the high consanguinity rate in these populations, which increases the percentage of autosomal recessive disorders and the homozygous LHCGR gene mutations.
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Affiliation(s)
- Heba Amin Hassan
- Medical Molecular Genetics Department, Division of Human Genetics and Genome Research, National Research Centre, 33 El Buhouth St., Dokki, Cairo, 12311, Egypt.
| | - M L Essawi
- Medical Molecular Genetics Department, Division of Human Genetics and Genome Research, National Research Centre, 33 El Buhouth St., Dokki, Cairo, 12311, Egypt
| | - M K Mekkawy
- Human Cytogenetics Department, Division of Human Genetics and Genome Research, National Research Centre, Cairo, Egypt
| | - I Mazen
- Clinical Genetics Department, Division of Human Genetics and Genome Research, National Research Centre, Cairo, Egypt
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Althumairy D, Zhang X, Baez N, Barisas G, Roess DA, Bousfield GR, Crans DC. Glycoprotein G-protein Coupled Receptors in Disease: Luteinizing Hormone Receptors and Follicle Stimulating Hormone Receptors. Diseases 2020; 8:E35. [PMID: 32942611 PMCID: PMC7565105 DOI: 10.3390/diseases8030035] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/22/2020] [Accepted: 08/26/2020] [Indexed: 12/14/2022] Open
Abstract
Signal transduction by luteinizing hormone receptors (LHRs) and follicle-stimulating hormone receptors (FSHRs) is essential for the successful reproduction of human beings. Both receptors and the thyroid-stimulating hormone receptor are members of a subset of G-protein coupled receptors (GPCRs) described as the glycoprotein hormone receptors. Their ligands, follicle-stimulating hormone (FSH) and luteinizing hormone (LH) and a structurally related hormone produced in pregnancy, human chorionic gonadotropin (hCG), are large protein hormones that are extensively glycosylated. Although the primary physiologic functions of these receptors are in ovarian function and maintenance of pregnancy in human females and spermatogenesis in males, there are reports of LHRs or FSHRs involvement in disease processes both in the reproductive system and elsewhere. In this review, we evaluate the aggregation state of the structure of actively signaling LHRs or FSHRs, their functions in reproduction as well as summarizing disease processes related to receptor mutations affecting receptor function or expression in reproductive and non-reproductive tissues. We will also present novel strategies for either increasing or reducing the activity of LHRs signaling. Such approaches to modify signaling by glycoprotein receptors may prove advantageous in treating diseases relating to LHRs or FSHRs function in addition to furthering the identification of new strategies for modulating GPCR signaling.
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Affiliation(s)
- Duaa Althumairy
- Cell and Molecular Biology Program, Colorado State University, Fort Collins, CO 80523, USA; (D.A.); (G.B.)
- Department of Biological Sciences, King Faisal University, Al-Ahsa 31982, Saudi Arabia
| | - Xiaoping Zhang
- Department of Chemistry, Colorado State University, Fort Collins, CO 80523, USA; (X.Z.); (N.B.)
| | - Nicholas Baez
- Department of Chemistry, Colorado State University, Fort Collins, CO 80523, USA; (X.Z.); (N.B.)
| | - George Barisas
- Cell and Molecular Biology Program, Colorado State University, Fort Collins, CO 80523, USA; (D.A.); (G.B.)
- Department of Chemistry, Colorado State University, Fort Collins, CO 80523, USA; (X.Z.); (N.B.)
| | - Deborah A. Roess
- Department of Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA;
| | - George R. Bousfield
- Department of Biological Sciences, Wichita State University, Wichita, KS 67260, USA;
| | - Debbie C. Crans
- Cell and Molecular Biology Program, Colorado State University, Fort Collins, CO 80523, USA; (D.A.); (G.B.)
- Department of Chemistry, Colorado State University, Fort Collins, CO 80523, USA; (X.Z.); (N.B.)
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Matsushima N, Takatsuka S, Miyashita H, Kretsinger RH. Leucine Rich Repeat Proteins: Sequences, Mutations, Structures and Diseases. Protein Pept Lett 2019; 26:108-131. [PMID: 30526451 DOI: 10.2174/0929866526666181208170027] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 11/26/2018] [Accepted: 11/26/2018] [Indexed: 12/18/2022]
Abstract
Mutations in the genes encoding Leucine Rich Repeat (LRR) containing proteins are associated with over sixty human diseases; these include high myopia, mitochondrial encephalomyopathy, and Crohn's disease. These mutations occur frequently within the LRR domains and within the regions that shield the hydrophobic core of the LRR domain. The amino acid sequences of fifty-five LRR proteins have been published. They include Nod-Like Receptors (NLRs) such as NLRP1, NLRP3, NLRP14, and Nod-2, Small Leucine Rich Repeat Proteoglycans (SLRPs) such as keratocan, lumican, fibromodulin, PRELP, biglycan, and nyctalopin, and F-box/LRR-repeat proteins such as FBXL2, FBXL4, and FBXL12. For example, 363 missense mutations have been identified. Replacement of arginine, proline, or cysteine by another amino acid, or the reverse, is frequently observed. The diverse effects of the mutations are discussed based on the known structures of LRR proteins. These mutations influence protein folding, aggregation, oligomerization, stability, protein-ligand interactions, disulfide bond formation, and glycosylation. Most of the mutations cause loss of function and a few, gain of function.
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Affiliation(s)
- Norio Matsushima
- Center for Medical Education, Sapporo Medical University, Sapporo 060-8556, Japan.,Institute of Tandem Repeats, Noboribetsu 059-0464, Japan
| | - Shintaro Takatsuka
- Center for Medical Education, Sapporo Medical University, Sapporo 060-8556, Japan
| | - Hiroki Miyashita
- Institute of Tandem Repeats, Noboribetsu 059-0464, Japan.,Hokubu Rinsho Co., Ltd, Sapporo 060-0061, Japan
| | - Robert H Kretsinger
- Department of Biology, University of Virginia, Charlottesville, VA 22904, United States
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Qiao J, Han B. Diseases caused by mutations in luteinizing hormone/chorionic gonadotropin receptor. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2018; 161:69-89. [PMID: 30711030 DOI: 10.1016/bs.pmbts.2018.09.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Accumulating evidence showed that the luteinizing hormone/chorionic gonadotropin receptor (LHCGR) is an essential regulator of sexual development and reproduction from zebrafish to human. Activating and inactivating mutations of LHCGR gene have been identified from patients of different phenotypes. Familial male-limited precocious puberty, Leydig cell hypoplasia, and empty follicle syndrome are caused by LHCGR mutations. More than 50 mutations have been reported from subjects of different ethnic backgrounds. Functional analyses of the mutant LHCGR revealed multiple defects, including cell surface expression, ligand binding, and signaling. The difference of the two native ligands and signaling pathway activated by LHCGR are illustrated. Potential therapeutic implications from the analyses of the naturally occurring LHCGR mutations, such as pharmacological chaperones, are highlighted.
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Affiliation(s)
- Jie Qiao
- Department of Endocrinology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China.
| | - Bing Han
- Department of Endocrinology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
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Newton CL, Anderson RC, Katz AA, Millar RP. Loss-of-Function Mutations in the Human Luteinizing Hormone Receptor Predominantly Cause Intracellular Retention. Endocrinology 2016; 157:4364-4377. [PMID: 27533885 DOI: 10.1210/en.2016-1104] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Mutations in G protein-coupled receptors (GPCRs) have been identified for many endocrine hormone signaling deficiencies. Inactivating mutations can impair ligand binding, receptor activation/coupling to signaling pathways, or can cause receptor misfolding and consequent impaired expression at the cell membrane. Here we examine the cell surface expression, ligand binding, and signaling of a range of mutant human luteinizing hormone receptors (LHRs) identified as causing reproductive dysfunction in human patients. The data obtained reveal how mutations in GPCRs can have diverse and severely deleterious effects on receptor function. Furthermore, it was found that impaired functionality of the majority of the mutant LHRs was due to reduced expression at the cell surface (14/20) while only two mutations caused impaired binding affinity and two impaired in signaling. An additional two mutations were found to cause no impairment of receptor function. These data demonstrate that the majority of LHR mutations lead to intracellular retention and highlight the potential for novel pharmacological chaperone therapeutics that can "rescue" expression/function of retained mutant GPCRs.
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Affiliation(s)
- Claire Louise Newton
- Centre for Neuroendocrinology (C.L.N., R.C.A., R.P.M.), Faculty of Health Sciences, University of Pretoria, Pretoria, 0001, South Africa; Department of Immunology (C.L.N), Faculty of Health Sciences, University of Pretoria, Pretoria, 0001, South Africa; UCT/MRC Receptor Biology Research Unit, Department of Integrative Biomedical Sciences and Institute of Infectious Diseases and Molecular Medicine (C.L.N., R.C.A., A.A.K., R.P.M.), Faculty of Health Sciences, University of Cape Town, Cape Town 7700, South Africa; Department of Zoology and Entomology (R.C.A), Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria, 0028, South Africa; SAMRC Gynaecology Cancer Research Centre (A.A.K), Department of Integrative Biomedical Sciences and Institute of Infectious Diseases and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, 7700, South Africa; and Department of Physiology (R.P.M), Faculty of Health Sciences, University of Pretoria, Pretoria, 0007, South Africa
| | - Ross Calley Anderson
- Centre for Neuroendocrinology (C.L.N., R.C.A., R.P.M.), Faculty of Health Sciences, University of Pretoria, Pretoria, 0001, South Africa; Department of Immunology (C.L.N), Faculty of Health Sciences, University of Pretoria, Pretoria, 0001, South Africa; UCT/MRC Receptor Biology Research Unit, Department of Integrative Biomedical Sciences and Institute of Infectious Diseases and Molecular Medicine (C.L.N., R.C.A., A.A.K., R.P.M.), Faculty of Health Sciences, University of Cape Town, Cape Town 7700, South Africa; Department of Zoology and Entomology (R.C.A), Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria, 0028, South Africa; SAMRC Gynaecology Cancer Research Centre (A.A.K), Department of Integrative Biomedical Sciences and Institute of Infectious Diseases and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, 7700, South Africa; and Department of Physiology (R.P.M), Faculty of Health Sciences, University of Pretoria, Pretoria, 0007, South Africa
| | - Arieh Anthony Katz
- Centre for Neuroendocrinology (C.L.N., R.C.A., R.P.M.), Faculty of Health Sciences, University of Pretoria, Pretoria, 0001, South Africa; Department of Immunology (C.L.N), Faculty of Health Sciences, University of Pretoria, Pretoria, 0001, South Africa; UCT/MRC Receptor Biology Research Unit, Department of Integrative Biomedical Sciences and Institute of Infectious Diseases and Molecular Medicine (C.L.N., R.C.A., A.A.K., R.P.M.), Faculty of Health Sciences, University of Cape Town, Cape Town 7700, South Africa; Department of Zoology and Entomology (R.C.A), Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria, 0028, South Africa; SAMRC Gynaecology Cancer Research Centre (A.A.K), Department of Integrative Biomedical Sciences and Institute of Infectious Diseases and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, 7700, South Africa; and Department of Physiology (R.P.M), Faculty of Health Sciences, University of Pretoria, Pretoria, 0007, South Africa
| | - Robert Peter Millar
- Centre for Neuroendocrinology (C.L.N., R.C.A., R.P.M.), Faculty of Health Sciences, University of Pretoria, Pretoria, 0001, South Africa; Department of Immunology (C.L.N), Faculty of Health Sciences, University of Pretoria, Pretoria, 0001, South Africa; UCT/MRC Receptor Biology Research Unit, Department of Integrative Biomedical Sciences and Institute of Infectious Diseases and Molecular Medicine (C.L.N., R.C.A., A.A.K., R.P.M.), Faculty of Health Sciences, University of Cape Town, Cape Town 7700, South Africa; Department of Zoology and Entomology (R.C.A), Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria, 0028, South Africa; SAMRC Gynaecology Cancer Research Centre (A.A.K), Department of Integrative Biomedical Sciences and Institute of Infectious Diseases and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, 7700, South Africa; and Department of Physiology (R.P.M), Faculty of Health Sciences, University of Pretoria, Pretoria, 0007, South Africa
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Nistal M, Paniagua R, González-Peramato P, Reyes-Múgica M. Perspectives in Pediatric Pathology, Chapter 6. Male Undermasculinization. Pediatr Dev Pathol 2015; 18:279-96. [PMID: 25105706 DOI: 10.2350/14-04-1465-pb.1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Normal male development requires three conditions: (1) adequate differentiation of the fetal testis; (2) synthesis and secretion of testicular hormones; and (3) effective action of these hormones on target organs. This requires the combined action of the inhibitory anti-müllerian hormone (AMH, secreted by Sertoli cells) to block the development of the uterus and fallopian tubes from the müllerian duct, together with the trophic stimulus of testosterone (a Leydig cell product), which leads to virilization of the wolffian ducts. Additionally, the development of external genitalia depends on the conversion of testosterone to dihydrotestosterone by the enzyme 5-α-reductase. Failure of any of these mechanisms leads to deficient virilization or the so-called "male pseudohermaphroditism" syndromes.
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Affiliation(s)
- Manuel Nistal
- 1 Pathology, Hospital La Paz, Universidad Autónoma de Madrid, Calle Arzobispo Morcillo #2, Madrid 28029, Spain
| | - Ricardo Paniagua
- 2 Department of Cell Biology, Universidad de Alcala, Madrid, Spain
| | - Pilar González-Peramato
- 1 Pathology, Hospital La Paz, Universidad Autónoma de Madrid, Calle Arzobispo Morcillo #2, Madrid 28029, Spain
| | - Miguel Reyes-Múgica
- 3 Department of Pathology, Children's Hospital of Pittsburgh of UPMC, One Children's Hospital Drive, 4401 Penn Avenue, Pittsburgh, PA 15224, USA
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Troppmann B, Kleinau G, Krause G, Gromoll J. Structural and functional plasticity of the luteinizing hormone/choriogonadotrophin receptor. Hum Reprod Update 2013; 19:583-602. [DOI: 10.1093/humupd/dmt023] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Aizen J, Kowalsman N, Kobayashi M, Hollander L, Sohn YC, Yoshizaki G, Niv MY, Levavi-Sivan B. Experimental and computational study of inter- and intra- species specificity of gonadotropins for various gonadotropin receptors. Mol Cell Endocrinol 2012; 364:89-100. [PMID: 22954681 DOI: 10.1016/j.mce.2012.08.013] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2012] [Revised: 08/20/2012] [Accepted: 08/21/2012] [Indexed: 12/22/2022]
Abstract
The gonadotropins follicle-stimulating hormone (FSH) and luteinizing hormone (LH) and their receptors play critical roles in vertebrate reproduction. In order to study intra- and interspecies ligand promiscuity of gonadotropins, COS-7 cells were transiently transfected with one of the gonadotropin receptor genes, FSHR or LHR, and tested for activation by gonadotropins from representative fish orders: Aquilliformes (eel; e), Salmoniformes (trout; tr), and Perciformes (tilapia; ta), and of mammalian origin: porcine (p), bovine (b) and human (h). The study reveals complex relations between the gonadotropin hormones and their receptors. Each gonadotropin activated its own cognate receptor. However, taLHR was also activated by hCG and eLHR was activated by hFSH, hCG, and trFSH. For FSHR, the only cross-reactivity detected was for hFSHR, which was activated by pFSH and bFSH. These findings are of great interest and applicability in the context of activation of various GTHRs by their ligands and by ligands from other vertebrates. Analysis of the three-dimensional models of the structures highlights the importance of residues outside of the currently established hormone-receptor interface region. In addition, the interface residues in taFSHR and the effect of exon duplication, which causes an insert in the LRR domain, are suggested to affect the interaction and binding of taFSH.
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Affiliation(s)
- Joseph Aizen
- The Robert H. Smith Faculty of Agriculture, Food and Environment, Department of Animal Sciences, The Hebrew University of Jerusalem, Rehovot 76100, Israel
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Rescue of expression and signaling of human luteinizing hormone G protein-coupled receptor mutants with an allosterically binding small-molecule agonist. Proc Natl Acad Sci U S A 2011; 108:7172-6. [PMID: 21482767 DOI: 10.1073/pnas.1015723108] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Naturally occurring mutations of G protein-coupled receptors (GPCRs) causing misfolding and failure to traffic to the cell surface can result in disease states. Some small-molecule orthosteric ligands can rescue such misfolded receptors, presumably by facilitating their correct folding and shuttling to the plasma membrane. Here we show that a cell-permeant, allosterically binding small-molecule agonist (Org 42599) rescues the folding and cell surface expression, and therefore target cell signaling, of mutant human luteinizing hormone (LH) receptors (A593P and S616Y) that cause Leydig cell hypoplasia in man. Both mutant receptors were retained in the cytoplasm whereas WT receptor localized at the cell membrane, and binding of LH to cells expressing the mutant receptors was markedly lower than to those expressing the WT receptor. Incubation with Org 42599 increased mutant receptor expression, cell surface localization, and the proportion of mutant receptor in the mature glycosylated form. Importantly, although LH stimulated little (S616Y) or no (A593P) activation of cells expressing mutant receptors, incubation of cells with Org 42599 facilitated rescue of expression and stimulation by the native ligand, LH. Although Org 42599 could activate these receptors, it could not displace (125)I-labeled human LH binding to the WT receptor, indicating that it acts in an allosteric manner. Here we demonstrate a small-molecule GPCR allosteric agonist that functionally rescues intracellularly retained mutant LH receptors by facilitating their cell surface expression. This approach may have application for treatment of infertile patients bearing such mutations and, more broadly, for other misfolded GPCR mutants resulting in human pathologic processes.
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Segaloff DL. Chapter 4 Diseases Associated with Mutations of the Human Lutropin Receptor. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2009; 89:97-114. [DOI: 10.1016/s1877-1173(09)89004-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Rocha A, Gómez A, Zanuy S, Cerdá-Reverter JM, Carrillo M. Molecular characterization of two sea bass gonadotropin receptors: cDNA cloning, expression analysis, and functional activity. Mol Cell Endocrinol 2007; 272:63-76. [PMID: 17543442 DOI: 10.1016/j.mce.2007.04.007] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2006] [Revised: 04/19/2007] [Accepted: 04/21/2007] [Indexed: 10/23/2022]
Abstract
The follicle-stimulating hormone (FSH) and the luteinizing hormone (LH) play central roles in vertebrate reproduction. They act through their cognate receptors to stimulate testicular and ovarian functions. The present study reports the cloning and characterization of two sea bass (Dicentrarchus labrax) cDNAs encoding a FSH receptor (sbsFSHR) and a LH receptor (sbsLHR). The mature proteins display typical features of the glycoprotein hormone receptor family members, but the sbsFSHR also contains some remarkable differences when compared with other fish or mammalian FSHRs. Among them, a distinct extracellular N-terminal cysteine domain as regards to its length and cysteine number, and the presence of an extra leucine-rich repeat. Expression analysis revealed that the sbsFSHR is exclusively expressed in gonadal tissues, specifically in the follicular wall of previtellogenic and early-vitellogenic follicles. On the contrary, sbsLHR mRNA was found to be widely distributed in sea bass somatic tissues. When stably expressed in mammalian cell lines, sbsFSHR was specifically stimulated by bovine FSH, while sbsLHR was activated by both bovine LH and FSH. Nevertheless, specific stimulation of the sbsLHR was observed when recombinant sea bass gonadotropins were used. The isolation of a FSHR and a LHR in sea bass opens new ways to study gonadotropin action in this species.
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Affiliation(s)
- Ana Rocha
- Department of Fish Physiology and Biotechnology, Instituto de Acuicultura de Torre la Sal, Consejo Superior de Investigaciones Cientificas, 12595 Torre la Sal, Ribera de Cabanes, Castellón, Spain
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