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Tang X, Miao Y, Cao L, Liu Y, Zhu X, Zhang J, Wang D, Li X, Zhang L, Huo J, Chen J. Adverse outcome pathway exploration of furan-induced liver fibrosis in rats: Genotoxicity pathway or oxidative stress pathway through CYP2E1 activation? CHEMOSPHERE 2023; 341:139998. [PMID: 37657698 DOI: 10.1016/j.chemosphere.2023.139998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 08/23/2023] [Accepted: 08/25/2023] [Indexed: 09/03/2023]
Abstract
Furan is a widespread endogenous contaminant in heat-processed foods that can accumulate rapidly in the food chain and has been widely detected in foods, such as wheat, bread, coffee, canned meat products, and baby food. Dietary exposure to this chemical may bring health risk. Furan is classified as a possible category 2B human carcinogen by the International Agency for Research on Cancer, with the liver as its primary target organ. Hepatic fibrosis is the most important nontumoral harmful effect of furan and also an important event in the carcinogenesis of furan. Although the specific mechanism of furan-induced liver fibrosis is still unclear, it may involve oxidative stress and genetic toxicity, in which the activation of cytochrome P450 2E1 (CYP2E1) may be the key event. Thus, we conducted a study using an integrating multi-endpoint genotoxicity platform in 120-day in vivo subchronic toxicity test in rats. Results showed that the rats with activated CYP2E1 exhibited DNA double-strand breaks in D4, gene mutations in D60, and increased expression of reactive oxygen species and nuclear factor erythroid 2-related factor 2 in D120. Necrosis, apoptosis, hepatic stellate cell activation, and fibrosis also occurred in the liver, suggesting that furan can independently affect liver fibrosis through oxidative stress and genotoxicity pathways. Point of Departure (PoD) was obtained by benchmark-dose (BMD) method to establish health-based guidance values. The human equivalent dose of PoD derived from BMDL05 was 2.26 μg/kg bw/d. The findings laid a foundation for the safety evaluation and risk assessment of furan and provided data for the further construction and improvement of the adverse outcome pathway network in liver fibrosis.
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Affiliation(s)
- Xinyao Tang
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, Sichuan, China; Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province, Chengdu, Sichuan, China
| | - Yeqiu Miao
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, Sichuan, China; Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province, Chengdu, Sichuan, China
| | - Li Cao
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, Sichuan, China; Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province, Chengdu, Sichuan, China
| | - Yufei Liu
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, Sichuan, China; Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province, Chengdu, Sichuan, China
| | - Xia Zhu
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, Sichuan, China; Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province, Chengdu, Sichuan, China
| | - Jing Zhang
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, Sichuan, China; Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province, Chengdu, Sichuan, China
| | - Dongxia Wang
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, Sichuan, China; Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province, Chengdu, Sichuan, China
| | - Xiaomeng Li
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, Sichuan, China; Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province, Chengdu, Sichuan, China
| | - Lishi Zhang
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, Sichuan, China; Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province, Chengdu, Sichuan, China
| | - Jiao Huo
- Department of Nutrition and Food Safety, Chongqing Center for Disease Control and Prevention, Chongqing, China.
| | - Jinyao Chen
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, Sichuan, China; Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province, Chengdu, Sichuan, China.
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2
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Citterio CE, Kim K, Rajesh B, Pena K, Clarke OB, Arvan P. Structural features of thyroglobulin linked to protein trafficking. Protein Sci 2023; 32:e4784. [PMID: 37717261 PMCID: PMC10578121 DOI: 10.1002/pro.4784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Revised: 09/06/2023] [Accepted: 09/14/2023] [Indexed: 09/19/2023]
Abstract
Thyroglobulin must pass endoplasmic reticulum (ER) quality control to become secreted for thyroid hormone synthesis. Defective thyroglobulin, blocked in trafficking, can cause hypothyroidism. Thyroglobulin is a large protein (~2750 residues) spanning regions I-II-III plus a C-terminal cholinesterase-like domain. The cholinesterase-like domain functions as an intramolecular chaperone for regions I-II-III, but the folding pathway leading to successful thyroglobulin trafficking remains largely unknown. Here, informed by the recent three-dimensional structure of thyroglobulin as determined by cryo-electron microscopy, we have bioengineered three novel classes of mutants yielding three entirely distinct quality control phenotypes. Specifically, upon expressing recombinant thyroglobulin, we find that first, mutations eliminating a disulfide bond enclosing a 200-amino acid loop in region I have surprisingly little impact on the ability of thyroglobulin to fold to a secretion-competent state. Next, we have identified a mutation on the surface of the cholinesterase-like domain that has no discernible effect on regional folding yet affects contact between distinct regions and thereby triggers impairment in the trafficking of full-length thyroglobulin. Finally, we have probed a conserved disulfide in the cholinesterase-like domain that interferes dramatically with local folding, and this defect then impacts on global folding, blocking the entire thyroglobulin in the ER. These data highlight variants with distinct effects on ER quality control, inhibiting domain-specific folding; folding via regional contact; neither; or both.
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Affiliation(s)
- Cintia E. Citterio
- Division of Metabolism, Endocrinology & Diabetes, Department of Internal MedicineUniversity of MichiganAnn ArborMichiganUSA
- Department of Biomedical and Pharmaceutical SciencesChapman UniversityIrvineCaliforniaUSA
| | - Kookjoo Kim
- Departments of Anesthesiology, and Physiology and Cellular BiophysicsIrving Institute for Clinical and Translational Research, Columbia University Irving Medical CenterNew YorkNew YorkUSA
| | - Bhavana Rajesh
- Division of Metabolism, Endocrinology & Diabetes, Department of Internal MedicineUniversity of MichiganAnn ArborMichiganUSA
| | - Kevin Pena
- Division of Metabolism, Endocrinology & Diabetes, Department of Internal MedicineUniversity of MichiganAnn ArborMichiganUSA
| | - Oliver Biggs Clarke
- Departments of Anesthesiology, and Physiology and Cellular BiophysicsIrving Institute for Clinical and Translational Research, Columbia University Irving Medical CenterNew YorkNew YorkUSA
| | - Peter Arvan
- Division of Metabolism, Endocrinology & Diabetes, Department of Internal MedicineUniversity of MichiganAnn ArborMichiganUSA
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3
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Tous C, Muñoz-Redondo C, Bravo-Gil N, Gavilan A, Fernández RM, Antiñolo J, Navarro-González E, Antiñolo G, Borrego S. Identification of Novel Candidate Genes for Familial Thyroid Cancer by Whole Exome Sequencing. Int J Mol Sci 2023; 24:ijms24097843. [PMID: 37175550 PMCID: PMC10178269 DOI: 10.3390/ijms24097843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 04/17/2023] [Accepted: 04/23/2023] [Indexed: 05/15/2023] Open
Abstract
Thyroid carcinoma (TC) can be classified as medullary (MTC) and non-medullary (NMTC). While most TCs are sporadic, familial forms of MTC and NMTC also exist (less than 1% and 3-9% of all TC cases, respectively). Germline mutations in RET are found in more than 95% of familial MTC, whereas familial NMTC shows a high degree of genetic heterogeneity. Herein, we aimed to identify susceptibility genes for familial NMTC and non-RET MTC by whole exome sequencing in 58 individuals belonging to 18 Spanish families with these carcinomas. After data analysis, 53 rare candidate segregating variants were identified in 12 of the families, 7 of them located in previously TC-associated genes. Although no common mutated genes were detected, biological processes regulating functions such as cell proliferation, differentiation, survival and adhesion were enriched. The reported functions of the identified genes together with pathogenicity and structural predictions, reinforced the candidacy of 36 of them, suggesting new loci related to TC and novel genotype-phenotype correlations. Therefore, our strategy provides clues to possible molecular mechanisms underlying familial forms of MTC and NMTC. These new molecular findings and clinical data of patients may be helpful for the early detection, development of tailored therapies and optimizing patient management.
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Affiliation(s)
- Cristina Tous
- Department of Maternofetal Medicine, Genetics and Reproduction, Institute of Biomedicine of Seville, University Hospital Virgen del Rocío/CSIC/University of Seville, 41013 Seville, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), 41013 Seville, Spain
| | - Carmen Muñoz-Redondo
- Department of Maternofetal Medicine, Genetics and Reproduction, Institute of Biomedicine of Seville, University Hospital Virgen del Rocío/CSIC/University of Seville, 41013 Seville, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), 41013 Seville, Spain
| | - Nereida Bravo-Gil
- Department of Maternofetal Medicine, Genetics and Reproduction, Institute of Biomedicine of Seville, University Hospital Virgen del Rocío/CSIC/University of Seville, 41013 Seville, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), 41013 Seville, Spain
| | - Angela Gavilan
- Department of Maternofetal Medicine, Genetics and Reproduction, Institute of Biomedicine of Seville, University Hospital Virgen del Rocío/CSIC/University of Seville, 41013 Seville, Spain
| | - Raquel María Fernández
- Department of Maternofetal Medicine, Genetics and Reproduction, Institute of Biomedicine of Seville, University Hospital Virgen del Rocío/CSIC/University of Seville, 41013 Seville, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), 41013 Seville, Spain
| | - Juan Antiñolo
- Department of Maternofetal Medicine, Genetics and Reproduction, Institute of Biomedicine of Seville, University Hospital Virgen del Rocío/CSIC/University of Seville, 41013 Seville, Spain
| | - Elena Navarro-González
- Center for Biomedical Network Research on Rare Diseases (CIBERER), 41013 Seville, Spain
- Department of Endocrinology and Nutrition, University Hospital Virgen del Rocío, 41013 Seville, Spain
| | - Guillermo Antiñolo
- Department of Maternofetal Medicine, Genetics and Reproduction, Institute of Biomedicine of Seville, University Hospital Virgen del Rocío/CSIC/University of Seville, 41013 Seville, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), 41013 Seville, Spain
| | - Salud Borrego
- Department of Maternofetal Medicine, Genetics and Reproduction, Institute of Biomedicine of Seville, University Hospital Virgen del Rocío/CSIC/University of Seville, 41013 Seville, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), 41013 Seville, Spain
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Siffo S, Gomes Pio M, Martínez EB, Lachlan K, Walker J, Weill J, González-Sarmiento R, Rivolta CM, Targovnik HM. The p.Pro2232Leu variant in the ChEL domain of thyroglobulin gene causes intracellular transport disorder and congenital hypothyroidism. Endocrine 2023; 80:47-53. [PMID: 36547798 DOI: 10.1007/s12020-022-03284-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 12/08/2022] [Indexed: 12/24/2022]
Abstract
Thyroglobulin (TG), the predominant glycoprotein of the thyroid gland, functions as matrix protein in thyroid hormonegenesis. TG deficiency results in thyroid dyshormonogenesis. These variants produce a heterogeneous spectrum of congenital goitre, with an autosomal recessive mode of inheritance. The purpose of this study was to identify and functionally characterize new variants in the TG gene in order to increase the understanding of the molecular mechanisms responsible for thyroid dyshormonogenesis. A total of four patients from two non-consanguineous families with marked alteration of TG synthesis were studied. The two families were previously analysed in our laboratory, only one deleterious allele, in each one, was detected after sequencing the TG gene (c.2359 C > T [p.Arg787*], c.5560 G > T [p.Glu1854*]). These findings were confirmed in the present studies by Next-Generation Sequencing. The single nucleotide coding variants of the TG gene were then analyzed to predict the possible variant causing the disease. The p.Pro2232Leu (c.6695 C > T), identified in both families, showing a low frequency population in gnomAD v2.1.1 database and protein homology, amino acid prediction, and 3D modeling analysis predict a potential pathogenic effect of this variant. We also transiently express p.Pro2232Leu in a full-length rat TG cDNA clone and confirmed that this point variant was sufficient to cause intracellular retention of mutant TG in HEK293T cells. Consequently, each family carried a compound heterozygous for p.Arg787*/p.Pro2232Leu or p.Glu1854*/p.Pro2232Leu variants. In conclusion, our results confirm the pathophysiological importance of altered TG folding as a consequence of missense variants located in the ChEL domain of TG.
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Affiliation(s)
- Sofia Siffo
- Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina
- CONICET-Universidad de Buenos Aires. Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Mauricio Gomes Pio
- Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina
- CONICET-Universidad de Buenos Aires. Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Elena Bueno Martínez
- Unidad de Medicina Molecular-Departamento de Medicina, IBMCC and IBSAL. Universidad de Salamanca-CSIC, Salamanca, España
| | - Katherine Lachlan
- Wessex Clinical Genetics Service, University Hospital Southampton, Princess Anne Hospital, SO16 5YA, Southampton, UK
| | - Joanna Walker
- Portsmouth Hospitals NHS Trust, Queen Alexandra Hospital, Cosham, PO6 3LY, Portsmouth, UK
| | - Jacques Weill
- Clinique de Pédiatrie, Hôpital Jeanne de Flandre, Centre Hospitalier Regional Universitaire de Lille, Lille, France
| | - Rogelio González-Sarmiento
- Unidad de Medicina Molecular-Departamento de Medicina, IBMCC and IBSAL. Universidad de Salamanca-CSIC, Salamanca, España
| | - Carina M Rivolta
- Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina
- CONICET-Universidad de Buenos Aires. Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Héctor M Targovnik
- Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina.
- CONICET-Universidad de Buenos Aires. Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina.
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5
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Hepatocellular BChE as a therapeutic target to ameliorate hypercholesterolemia through PRMT5 selective degradation to restore LDL receptor transcription. Life Sci 2022; 293:120336. [PMID: 35065166 DOI: 10.1016/j.lfs.2022.120336] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 01/03/2022] [Accepted: 01/14/2022] [Indexed: 11/22/2022]
Abstract
AIMS Individuals with nonalcoholic hepatosteatosis (NAFLD) have a worse atherogenic lipoprotein profile and are susceptible to cardiovascular diseases. The MEK-ERK signaling cascades are central regulators of the levels of LDL receptor (LDLR), a major determinant of circulating cholesterol. It is elusive how hepatic steatosis contributes to dyslipidemia, especially hypercholesterolemia. MAIN METHODS The effects of BChE on signaling pathways were determined by immunoblotting in a BChE knockout hepatocyte cell line. DiI-LDL probe was used to explore the effect of BChE expression on LDL internalization. Co-immunoprecipitation and LC-MS were used to explore the interacting proteins with BChE. Finally, a hepatocyte-restricted BChE silencing mouse model was established by AAV8-Tbg-shRNA, and the hypercholesterolemia was induced by 65% kcal% high-fat, high-sucrose diet feeding. MAIN FINDINGS Here we demonstrate that butyrylcholinesterase (BChE) governs the LDL receptor levels and LDL uptake capacity through the MEK-ERK signaling cascades to promote Ldlr transcription. BChE interacts and co-localizes with PRMT5, a protein methylation modifier controlling the ERK signaling. PRMT5 regulates LDLR-dependent LDL uptake and is a substrate of chaperone-mediated autophagy (CMA). BChE deficiency induces the PRTM5 degradation dependent on CMA activity, possibly through facilitating the HSC70 (Heat shock cognate 71 kDa) recognition of PRMT5. Remarkably, in vivo hepatocyte-restricted BChE silencing reduces plasma cholesterol levels substantially. In contrast, the BChE knockout mice are predisposed to hypercholesterolemia. SIGNIFICANCE Taken together, these findings outline a regulatory role for the BChE-PRMT5-ERK-LDLR axis in hepatocyte cholesterol metabolism, and suggest that targeting liver BChE is an effective therapeutic strategy to treat hypercholesterolemia.
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6
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Adaixo R, Steiner EM, Righetto RD, Schmidt A, Stahlberg H, Taylor NMI. Cryo-EM structure of native human thyroglobulin. Nat Commun 2022; 13:61. [PMID: 35013249 PMCID: PMC8748809 DOI: 10.1038/s41467-021-27693-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 12/02/2021] [Indexed: 01/26/2023] Open
Abstract
The thyroglobulin (TG) protein is essential to thyroid hormone synthesis, plays a vital role in the regulation of metabolism, development and growth and serves as intraglandular iodine storage. Its architecture is conserved among vertebrates. Synthesis of triiodothyronine (T3) and thyroxine (T4) hormones depends on the conformation, iodination and post-translational modification of TG. Although structural information is available on recombinant and deglycosylated endogenous human thyroglobulin (hTG) from patients with goiters, the structure of native, fully glycosylated hTG remained unknown. Here, we present the cryo-electron microscopy structure of native and fully glycosylated hTG from healthy thyroid glands to 3.2 Å resolution. The structure provides detailed information on hormonogenic and glycosylation sites. We employ liquid chromatography–mass spectrometry (LC-MS) to validate these findings as well as other post-translational modifications and proteolytic cleavage sites. Our results offer insights into thyroid hormonogenesis of native hTG and provide a fundamental understanding of clinically relevant mutations. The iodinated thyroglobulin functions as iodine storage and carrier protein and a precursor for thyroid hormone (TH) biogenesis. Here, the authors report the structure of native, fully glycosylated human thyroglobulin, revealing the location of the hTg hormonogenic and glycosylation sites.
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Affiliation(s)
- Ricardo Adaixo
- Center for Cellular Imaging and NanoAnalytics, Biozentrum, University of Basel, Mattenstrasse 26, 4058, Basel, Switzerland
| | - Eva M Steiner
- Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark
| | - Ricardo D Righetto
- Center for Cellular Imaging and NanoAnalytics, Biozentrum, University of Basel, Mattenstrasse 26, 4058, Basel, Switzerland
| | - Alexander Schmidt
- Proteomics Core Facility, Biozentrum, University of Basel, Klingelbergstrasse 72, 4058, Basel, Switzerland
| | - Henning Stahlberg
- Center for Cellular Imaging and NanoAnalytics, Biozentrum, University of Basel, Mattenstrasse 26, 4058, Basel, Switzerland. .,Lab. of Biol. Electron Microscopy, Institute of Physics, SB, EPFL, and Department of Fund. Microbiol., Faculty of Biology and Medicine, UNIL, 1015, Lausanne, Switzerland.
| | - Nicholas M I Taylor
- Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark.
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7
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Pio MG, Siffo S, Scheps KG, Molina MF, Adrover E, Abelleyro MM, Rivolta CM, Targovnik HM. Curating the gnomAD database: Report of novel variants in the thyrogobulin gene using in silico bioinformatics algorithms. Mol Cell Endocrinol 2021; 534:111359. [PMID: 34119605 DOI: 10.1016/j.mce.2021.111359] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 06/01/2021] [Accepted: 06/02/2021] [Indexed: 01/09/2023]
Abstract
Thyroglobulin (TG) is a large glycosylated protein of 2767 amino acids, secreted by the thyrocytes into the follicular lumen. It plays an essential role in the process of thyroid hormone synthesis. TG gene variants lead to permanent congenital hypothyroidism. In the present work, we report a detailed population and bioinformatic prediction analyses of the TG variants indexed in the Genome Aggregation Database (gnomAD). The results showed a clear predominance of nonsense variants in the European (Finnish), European (Non-Finnish) and Ashkenazi Jewish ethnic groups, whereas the splice site variants predominate in South Asian and African/African-American populations. In total, 282 novel TG variants were described (47 missense involving the wild-type cysteine residues, 177 missense located in the ChEL domain and 58 splice site variants) which were not reported in the literature and that would have deleterious effects in prediction programs. In the gnomAD population, the estimated prevalence of heterozygous carriers of the potentially damaging variants was 1:320. In conclusion, we provide an updated and curated reference source for the diagnosis of thyroid disease, mainly to congenital hypothyroidism due to TG deficiency. The identification and characterization of TG variants is undoubtedly a valuable approach to study the TG structure/function relations and an important tool for clinical diagnosis and genetic counseling.
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Affiliation(s)
- Mauricio Gomes Pio
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Sofia Siffo
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Karen G Scheps
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Maricel F Molina
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Ezequiela Adrover
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Miguel M Abelleyro
- CONICET-Academia Nacional de Medicina, Instituto de Medicina Experimental (IMEX), Buenos Aires, Argentina
| | - Carina M Rivolta
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Héctor M Targovnik
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina.
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8
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Zhang X, Kellogg AP, Citterio CE, Zhang H, Larkin D, Morishita Y, Targovnik HM, Balbi VA, Arvan P. Thyroid hormone synthesis continues despite biallelic thyroglobulin mutation with cell death. JCI Insight 2021; 6:148496. [PMID: 33914707 PMCID: PMC8262357 DOI: 10.1172/jci.insight.148496] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 04/28/2021] [Indexed: 11/17/2022] Open
Abstract
Complete absence of thyroid hormone is incompatible with life in vertebrates. Thyroxine is synthesized within thyroid follicles upon iodination of thyroglobulin conveyed from the endoplasmic reticulum (ER), via the Golgi complex, to the extracellular follicular lumen. In congenital hypothyroidism from biallelic thyroglobulin mutation, thyroglobulin is misfolded and cannot advance from the ER, eliminating its secretion and triggering ER stress. Nevertheless, untreated patients somehow continue to synthesize sufficient thyroxine to yield measurable serum levels that sustain life. Here, we demonstrate that TGW2346R/W2346R humans, TGcog/cog mice, and TGrdw/rdw rats exhibited no detectable ER export of thyroglobulin, accompanied by severe thyroidal ER stress and thyroid cell death. Nevertheless, thyroxine was synthesized, and brief treatment of TGrdw/rdw rats with antithyroid drug was lethal to the animals. When untreated, remarkably, thyroxine was synthesized on the mutant thyroglobulin protein, delivered via dead thyrocytes that decompose within the follicle lumen, where they were iodinated and cannibalized by surrounding live thyrocytes. As the animals continued to grow goiters, circulating thyroxine increased. However, when TGrdw/rdw rats age, they cannot sustain goiter growth that provided the dying cells needed for ongoing thyroxine synthesis, resulting in profound hypothyroidism. These results establish a disease mechanism wherein dead thyrocytes support organismal survival.
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Affiliation(s)
- Xiaohan Zhang
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan, Ann Arbor, Michigan, USA
| | - Aaron P Kellogg
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan, Ann Arbor, Michigan, USA
| | - Cintia E Citterio
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan, Ann Arbor, Michigan, USA.,Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo, Buenos Aires, Argentina
| | - Hao Zhang
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan, Ann Arbor, Michigan, USA
| | - Dennis Larkin
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan, Ann Arbor, Michigan, USA
| | - Yoshiaki Morishita
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan, Ann Arbor, Michigan, USA.,Division of Diabetes, Department of Internal Medicine, Aichi Medical University, Nagakute, Japan
| | - Héctor M Targovnik
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo, Buenos Aires, Argentina
| | - Viviana A Balbi
- Department of Endocrinology and Growth, Hospital de Niños Sor María Ludovica, La Plata, Argentina
| | - Peter Arvan
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan, Ann Arbor, Michigan, USA
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9
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Citterio CE, Rivolta CM, Targovnik HM. Structure and genetic variants of thyroglobulin: Pathophysiological implications. Mol Cell Endocrinol 2021; 528:111227. [PMID: 33689781 DOI: 10.1016/j.mce.2021.111227] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 01/22/2021] [Accepted: 02/23/2021] [Indexed: 02/07/2023]
Abstract
Thyroglobulin (TG) plays a main role in the biosynthesis of thyroid hormones (TH), and, thus, it is involved in a wide range of vital functions throughout the life cycle of all vertebrates. Deficiency of TH production due to TG genetic variants causes congenital hypothyroidism (CH), with devastating consequences such as intellectual disability and impaired growth if untreated. To this day, 229 variations in the human TG gene have been identified while the 3D structure of TG has recently appeared. Although TG deficiency is thought to be of autosomal recessive inheritance, the introduction of massive sequencing platforms led to the identification of a variety of monoallelic TG variants (combined with mutations in other thyroid gene products) opening new questions regarding the possibility of oligogenic inheritance of the disease. In this review we discuss remarkable advances in the understanding of the TG architecture and the pathophysiology of CH associated with TG defects, providing new insights for the management of congenital disorders as well as counseling benefits for families with a history of TG abnormalities. Moreover, we summarize relevant aspects of TH synthesis within TG and offer an updated analysis of animal and cellular models of TG deficiency for pathophysiological studies of thyroid dyshormonogenesis while highlighting perspectives for new investigations. All in all, even though there has been sustained progress in understanding the role of TG in thyroid pathophysiology during the past 50 years, functional characterization of TG variants remains an important area of study for future advancement in the field.
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Affiliation(s)
- Cintia E Citterio
- Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires. Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Carina M Rivolta
- Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires. Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Héctor M Targovnik
- Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires. Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina.
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10
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Morishita Y, Kellogg AP, Larkin D, Chen W, Vadrevu S, Satin L, Liu M, Arvan P. Cell death-associated lipid droplet protein CIDE-A is a noncanonical marker of endoplasmic reticulum stress. JCI Insight 2021; 6:143980. [PMID: 33661766 PMCID: PMC8119190 DOI: 10.1172/jci.insight.143980] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 03/02/2021] [Indexed: 01/05/2023] Open
Abstract
Secretory protein misfolding has been linked to ER stress and cell death. We expressed a TGrdw transgene encoding TG-G(2298)R, a misfolded mutant thyroglobulin reported to be linked to thyroid cell death. When the TGrdw transgene was expressed at low level in thyrocytes of TGcog/cog mice that experienced severe ER stress, we observed increased thyrocyte cell death and increased expression of CIDE-A (cell death-inducing DFFA-like effector-A, a protein of lipid droplets) in whole thyroid gland. Here we demonstrate that acute ER stress in cultured PCCL3 thyrocytes increases Cidea mRNA levels, maintained at least in part by increased mRNA stability, while being negatively regulated by activating transcription factor 6 - with similar observations that ER stress increases Cidea mRNA levels in other cell types. CIDE-A protein is sensitive to proteasomal degradation yet is stabilized by ER stress, and elevated expression levels accompany increased cell death. Unlike acute ER stress, PCCL3 cells adapted and surviving chronic ER stress maintained a disproportionately lower relative mRNA level of Cidea compared with that of other, classical ER stress markers, as well as a blunted Cidea mRNA response to a new, unrelated acute ER stress challenge. We suggest that CIDE-A is a novel marker linked to a noncanonical ER stress response program, with implications for cell death and survival.
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Affiliation(s)
- Yoshiaki Morishita
- Division of Metabolism, Endocrinology & Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
- Division of Diabetes, Department of Internal Medicine, Aichi Medical University, Aichi, Japan
| | - Aaron P. Kellogg
- Division of Metabolism, Endocrinology & Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Dennis Larkin
- Division of Metabolism, Endocrinology & Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Wei Chen
- Division of Metabolism, Endocrinology & Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Suryakiran Vadrevu
- Department of Pharmacology, University of Michigan Medical Center, Ann Arbor, Michigan, USA
| | - Leslie Satin
- Division of Metabolism, Endocrinology & Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
- Department of Pharmacology, University of Michigan Medical Center, Ann Arbor, Michigan, USA
| | - Ming Liu
- Division of Metabolism, Endocrinology & Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
- Department of Endocrinology & Diabetes, Tianjin Medical University, Tianjin, China
| | - Peter Arvan
- Division of Metabolism, Endocrinology & Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
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11
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Wright MT, Kouba L, Plate L. Thyroglobulin Interactome Profiling Defines Altered Proteostasis Topology Associated With Thyroid Dyshormonogenesis. Mol Cell Proteomics 2020; 20:100008. [PMID: 33581410 PMCID: PMC7950113 DOI: 10.1074/mcp.ra120.002168] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Revised: 10/15/2020] [Accepted: 11/18/2020] [Indexed: 12/02/2022] Open
Abstract
Thyroglobulin (Tg) is a secreted iodoglycoprotein serving as the precursor for triiodothyronine and thyroxine hormones. Many characterized Tg gene mutations produce secretion-defective variants resulting in congenital hypothyroidism. Tg processing and secretion is controlled by extensive interactions with chaperone, trafficking, and degradation factors comprising the secretory proteostasis network. While dependencies on individual proteostasis network components are known, the integration of proteostasis pathways mediating Tg protein quality control and the molecular basis of mutant Tg misprocessing remain poorly understood. We employ a multiplexed quantitative affinity purification-mass spectrometry approach to define the Tg proteostasis interactome and changes between WT and several congenital hypothyroidism variants. Mutant Tg processing is associated with common imbalances in proteostasis engagement including increased chaperoning, oxidative folding, and engagement by targeting factors for endoplasmic reticulum-associated degradation. Furthermore, we reveal mutation-specific changes in engagement with N-glycosylation components, suggesting distinct requirements for 1 Tg variant on dual engagement of both oligosaccharyltransferase complex isoforms for degradation. Modulating dysregulated proteostasis components and pathways may serve as a therapeutic strategy to restore Tg secretion and thyroid hormone biosynthesis.
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Affiliation(s)
- Madison T Wright
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee, USA
| | - Logan Kouba
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Lars Plate
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee, USA; Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA.
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12
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Bruellman RJ, Watanabe Y, Ebrhim RS, Creech MK, Abdullah MA, Dumitrescu AM, Refetoff S, Weiss RE. Increased Prevalence of TG and TPO Mutations in Sudanese Children With Congenital Hypothyroidism. J Clin Endocrinol Metab 2020; 105:5684913. [PMID: 31867598 PMCID: PMC7093074 DOI: 10.1210/clinem/dgz297] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Accepted: 12/17/2019] [Indexed: 12/21/2022]
Abstract
CONTEXT Congenital hypothyroidism (CH) is due to dyshormonogenesis in 10% to 15% of subjects worldwide but accounts for 60% of CH cases in the Sudan. OBJECTIVE To investigate the molecular basis of CH in Sudanese families. DESIGN Clinical phenotype reporting and serum thyroid hormone measurements. Deoxyribonucelic acid extraction for whole-exome sequencing and Sanger sequencing. SETTING University research center. PATIENTS Twenty-six Sudanese families with CH. INTERVENTION Clinical evaluation, thyroid function tests, genetic sequencing, and analysis. Our samples and information regarding samples from the literature were used to compare TG (thyroglobulin) and TPO (thyroid peroxidase) mutation rates in the Sudanese population with all populations. RESULTS Mutations were found in dual-oxidase 1 (DUOX1), dual-oxidase 2 (DUOX2), iodotyrosine deiodinase (IYD), solute-carrier (SLC) 26A4, SLC26A7, SLC5A5, TG, and TPO genes. The molecular basis of the CH in 7 families remains unknown. TG mutations were significantly higher on average in the Sudanese population compared with the average number of TG mutations in other populations (P < 0.05). CONCLUSIONS All described mutations occur in domains important for protein structure and function, predicting the CH phenotype. Genotype prediction based on phenotype includes low or undetectable thyroglobulin levels for TG gene mutations and markedly higher thyroglobulin levels for TPO mutations. The reasons for higher incidence of TG gene mutations include gene length and possible positive genetic selection due to endemic iodine deficiency.
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Affiliation(s)
- Ryan J Bruellman
- Department of Medicine, University of Miami Miller School of Medicine, Miami, Florida
| | - Yui Watanabe
- Department of Medicine, University of Miami Miller School of Medicine, Miami, Florida
| | - Reham S Ebrhim
- Department of Paediatrics and Child Health, Faculty of Medicine, University of Almughtaribeen, Khartoum, Sudan
| | - Matthew K Creech
- Department of Medicine, University of Miami Miller School of Medicine, Miami, Florida
| | - Mohamed A Abdullah
- Department of Paediatrics and Child Health, Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Alexandra M Dumitrescu
- Department of Medicine, The University of Chicago, Chicago, Illinois
- Committee on Molecular Medicine and Nutrition, The University of Chicago, Chicago, Illinois
| | - Samuel Refetoff
- Department of Medicine, The University of Chicago, Chicago, Illinois
- Department of Pediatrics, The University of Chicago, Chicago, Illinois
- Committee on Genetics, The University of Chicago, Chicago, Illinois
| | - Roy E Weiss
- Department of Medicine, University of Miami Miller School of Medicine, Miami, Florida
- Correspondence and Reprint Requests: Roy E. Weiss, MD, PhD, University of Miami Miller School of Medicine, 1120 NW 14th Street, Room 310F, Miami, Florida 33136. E-mail:
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13
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Citterio CE, Siffo S, Moya CM, Pio MG, Molina MF, Scheps KG, Rey OA, Arvan P, Rivolta CM, Targovnik HM. p.L571P in the linker domain of rat thyroglobulin causes intracellular retention. Mol Cell Endocrinol 2020; 505:110719. [PMID: 31972331 DOI: 10.1016/j.mce.2020.110719] [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: 09/30/2019] [Revised: 01/14/2020] [Accepted: 01/14/2020] [Indexed: 12/14/2022]
Abstract
Thyroglobulin (TG), a large glycosylated protein secreted by thyrocytes into the thyroid follicular lumen, plays an essential role in thyroid hormone biosynthesis. Rattus norvegicus TG (rTG) is encoded by a large single copy gene, 186-kb long, located on chromosome 7 composed of 48 exons encoding a 8461-kb mRNA. Although the TG gene displays sequence variability, many missense mutations do not impose any adverse effect on the TG protein, whereas other nucleotide substitutions may affect its TG stability and/or TG intracellular trafficking. In order to gain a further understanding of the protein domains regulating its intracellular fate, we cloned a full-length cDNA from rTG into the pcDNA6/V5-His B expression vector. However, transient expression of the cDNA in HEK293T cells showed that the encoded protein was not a wild-type molecule, as it was unable to be secreted in the culture supernatant. Sequencing analyses revealed three random mutations, which accidentally emerged during the course of cloning: c.1712T>C [p.L571P] in the linker domain (amino acid positions 360 to 604), c.2027A>G [p.Q676R] in TG type 1-6 repeat and c.2720A>G [p.Q907R] in the TG type 1-7 repeat. Expression of cDNAs encoding a combination of two mutations [p.Q676R-p.Q907R], [p.L571P-p.Q907R] or [p.L571P-p.Q676R] indicated that any TG bearing the p.L571P substitution was trapped intracellularly. Indeed, we expressed the single point mutant p.L571P and confirmed that this point mutation was sufficient to cause intracellular retention of mutant TG in HEK293T cells. Endo H analysis showed that the p.L571P mutant is completely sensitive to the enzyme, whereas the will-type TG acquires full N-glycan modifications in Golgi apparatus. This data suggest that the p.L571P mutant contains the mannose-type N-glycan, that was added at the first stage of glycosylation. Complex-type N-glycan formation in the Golgi apparatus does not occur, consistent with defective endoplasmic reticulum exit of the mutant TG. Moreover, predictive analysis of the 3D linker domain showed that the p.L571P mutation would result in a significant protein conformational change. In conclusion, our studies identified a novel amino acid residue within the linker domain of TG associated with its conformational maturation and intracellular trafficking.
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Affiliation(s)
- Cintia E Citterio
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Sofia Siffo
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Christian M Moya
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina
| | - Mauricio Gomes Pio
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Maricel F Molina
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Karen G Scheps
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Osvaldo A Rey
- CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Peter Arvan
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical School, Ann Arbor, USA
| | - Carina M Rivolta
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Héctor M Targovnik
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina.
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14
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Targovnik HM, Scheps KG, Rivolta CM. Defects in protein folding in congenital hypothyroidism. Mol Cell Endocrinol 2020; 501:110638. [PMID: 31751626 DOI: 10.1016/j.mce.2019.110638] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 10/21/2019] [Accepted: 11/01/2019] [Indexed: 12/26/2022]
Abstract
Primary congenital hypothyroidism (CH) is the most common endocrine disease in children and one of the most common preventable causes of both cognitive and motor deficits. CH is a heterogeneous group of thyroid disorders in which inadequate production of thyroid hormone occurs due to defects in proteins involved in the gland organogenesis (dysembryogenesis) or in multiple steps of thyroid hormone biosynthesis (dyshormonogenesis). Dysembryogenesis is associated with genes responsible for the development or growth of thyroid cells: such as NKX2-1, FOXE1, PAX8, NKX2-5, TSHR, TBX1, CDCA8, HOXD3 and HOXB3 resulting in agenesis, hypoplasia or ectopia of thyroid gland. Nevertheless, the etiology of the dysembryogenesis remains unknown for most cases. In contrast, the majority of patients with dyshormonogenesis has been linked to mutations in the SLC5A5, SLC26A4, SLC26A7, TPO, DUOX1, DUOX2, DUOXA1, DUOXA2, IYD or TG genes, which usually originate goiter. About 800 genetic mutations have been reported to cause CH in patients so far, including missense, nonsense, in-frame deletion and splice-site variations. Many of these mutations are implicated in specific domains, cysteine residues or glycosylation sites, affecting the maturation of nascent proteins that go through the secretory pathway. Consequently, misfolded proteins are permanently entrapped in the endoplasmic reticulum (ER) and are translocated to the cytosol for proteasomal degradation by the ER-associated degradation (ERAD) machinery. Despite of all these remarkable advances in the field of the CH pathogenesis, several points on the development of this disease remain to be elucidated. The continuous study of thyroid gene mutations with the application of new technologies will be useful for the understanding of the intrinsic mechanisms related to CH. In this review we summarize the present status of knowledge on the disorders in the protein folding caused by thyroid genes mutations.
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Affiliation(s)
- Héctor M Targovnik
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina.
| | - Karen G Scheps
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Carina M Rivolta
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
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15
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Abstract
In humans, the thyroid hormones T3 and T4 are synthesized in the thyroid gland in a process that crucially involves the iodoglycoprotein thyroglobulin. The overall structure of thyroglobulin is conserved in all vertebrates. Upon thyroglobulin delivery from thyrocytes to the follicular lumen of the thyroid gland via the secretory pathway, multiple tyrosine residues can become iodinated to form mono-iodotyrosine (MIT) and/or di-iodotyrosine (DIT); however, selective tyrosine residues lead to preferential formation of T4 and T3 at distinct sites. T4 formation involves oxidative coupling between two DIT side chains, and de novo T3 formation involves coupling between an MIT donor and a DIT acceptor. Thyroid hormone synthesis is stimulated by TSH activating its receptor (TSHR), which upregulates the activity of many thyroid gene products involved in hormonogenesis. Additionally, TSH regulates post-translational changes in thyroglobulin that selectively enhance its capacity for T3 formation - this process is important in iodide deficiency and in Graves disease. 167 different mutations, many of which are newly discovered, are now known to exist in TG (encoding human thyroglobulin) that can lead to defective thyroid hormone synthesis, resulting in congenital hypothyroidism.
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Affiliation(s)
- Cintia E Citterio
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología y Biotecnología/Cátedra de Genética, Buenos Aires, Argentina
- CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Héctor M Targovnik
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología y Biotecnología/Cátedra de Genética, Buenos Aires, Argentina
- CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Peter Arvan
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical School, Ann Arbor, MI, USA.
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16
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Pfeifer A, Rusinek D, Żebracka-Gala J, Czarniecka A, Chmielik E, Zembala-Nożyńska E, Wojtaś B, Gielniewski B, Szpak-Ulczok S, Oczko-Wojciechowska M, Krajewska J, Polańska J, Jarząb B. Novel TG-FGFR1 and TRIM33-NTRK1 transcript fusions in papillary thyroid carcinoma. Genes Chromosomes Cancer 2019; 58:558-566. [PMID: 30664823 PMCID: PMC6594006 DOI: 10.1002/gcc.22737] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 01/14/2019] [Accepted: 01/15/2019] [Indexed: 02/06/2023] Open
Abstract
Papillary thyroid carcinoma (PTC) is most common among all thyroid cancers. Multiple genomic alterations occur in PTC, and gene rearrangements are one of them. Here we screened 14 tumors for novel fusion transcripts by RNA‐Seq. Two samples harboring RET/PTC1 and RET/PTC3 rearrangements were positive controls whereas the remaining ones were negative regarding the common PTC alterations. We used Sanger sequencing to validate potential fusions. We detected 2 novel potentially oncogenic transcript fusions: TG‐FGFR1 and TRIM33‐NTRK1. We detected 4 novel fusion transcripts of unknown significance accompanying the TRIM33‐NTRK1 fusion: ZSWIM5‐TP53BP2, TAF4B‐WDR1, ABI2‐MTA3, and ARID1B‐PSMA1. Apart from confirming the presence of RET/PTC1 and RET/PTC3 in positive control samples, we also detected known oncogenic fusion transcripts in remaining samples: TFG‐NTRK1, ETV6‐NTRK3, MKRN1‐BRAF, EML4‐ALK, and novel isoform of CCDC6‐RET.
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Affiliation(s)
- Aleksandra Pfeifer
- Department of Nuclear Medicine and Endocrine Oncology, Maria Sklodowska-Curie Institute - Oncology Center Gliwice Branch, Gliwice, Poland
| | - Dagmara Rusinek
- Department of Nuclear Medicine and Endocrine Oncology, Maria Sklodowska-Curie Institute - Oncology Center Gliwice Branch, Gliwice, Poland
| | - Jadwiga Żebracka-Gala
- Department of Nuclear Medicine and Endocrine Oncology, Maria Sklodowska-Curie Institute - Oncology Center Gliwice Branch, Gliwice, Poland
| | - Agnieszka Czarniecka
- Department of Oncological and Reconstructive Surgery, Maria Sklodowska-Curie Institute - Oncology Center Gliwice Branch, Gliwice, Poland
| | - Ewa Chmielik
- Tumor Pathology Department, Maria Sklodowska-Curie Institute - Oncology Center Gliwice Branch, Gliwice, Poland
| | - Ewa Zembala-Nożyńska
- Tumor Pathology Department, Maria Sklodowska-Curie Institute - Oncology Center Gliwice Branch, Gliwice, Poland
| | - Bartosz Wojtaś
- Laboratory of Molecular Neurobiology, Neurobiology Center, Nencki Institute of Experimental Biology, Warsaw, Poland
| | - Bartłomiej Gielniewski
- Laboratory of Molecular Neurobiology, Neurobiology Center, Nencki Institute of Experimental Biology, Warsaw, Poland
| | - Sylwia Szpak-Ulczok
- Department of Nuclear Medicine and Endocrine Oncology, Maria Sklodowska-Curie Institute - Oncology Center Gliwice Branch, Gliwice, Poland
| | - Małgorzata Oczko-Wojciechowska
- Department of Nuclear Medicine and Endocrine Oncology, Maria Sklodowska-Curie Institute - Oncology Center Gliwice Branch, Gliwice, Poland
| | - Jolanta Krajewska
- Department of Nuclear Medicine and Endocrine Oncology, Maria Sklodowska-Curie Institute - Oncology Center Gliwice Branch, Gliwice, Poland
| | - Joanna Polańska
- Faculty of Automatic Control, Electronics and Computer Science, Silesian University of Technology, Gliwice, Poland
| | - Barbara Jarząb
- Department of Nuclear Medicine and Endocrine Oncology, Maria Sklodowska-Curie Institute - Oncology Center Gliwice Branch, Gliwice, Poland
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17
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Siffo S, Adrover E, Citterio CE, Miras MB, Balbi VA, Chiesa A, Weill J, Sobrero G, González VG, Papendieck P, Martinez EB, Gonzalez-Sarmiento R, Rivolta CM, Targovnik HM. Molecular analysis of thyroglobulin mutations found in patients with goiter and hypothyroidism. Mol Cell Endocrinol 2018; 473:1-16. [PMID: 29275168 DOI: 10.1016/j.mce.2017.12.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 11/22/2017] [Accepted: 12/18/2017] [Indexed: 01/23/2023]
Abstract
Thyroid dyshormonogenesis due to thyroglobulin (TG) gene mutations have an estimated incidence of approximately 1 in 100,000 newborns. The clinical spectrum ranges from euthyroid to mild or severe hypothyroidism. Up to now, one hundred seventeen deleterious mutations in the TG gene have been identified and characterized. The purpose of the present study was to identify and characterize new mutations in the TG gene. We report eight patients from seven unrelated families with goiter, hypothyroidism and low levels of serum TG. All patients underwent clinical, biochemical and image evaluation. Sequencing of DNA, genotyping, as well as bioinformatics analysis were performed. Molecular analyses revealed three novel inactivating TG mutations: c.5560G>T [p.E1835*], c.7084G>C [p.A2343P] and c.7093T>C [p.W2346R], and four previously reported mutations: c.378C>A [p.Y107*], c.886C>T [p.R277*], c.1351C>T [p.R432*] and c.7007G>A [p.R2317Q]. Two patients carried homozygous mutations (p.R277*/p.R277*, p.W2346R/p.W2346R), four were compound heterozygous mutations (p.Y107*/p.R277* (two unrelated patients), p.R432*/p.A2343P, p.Y107*/p.R2317Q) and two siblings from another family had a single p.E1835* mutated allele. Additionally, we include the analysis of 48 patients from 31 unrelated families with TG mutations identified in our present and previous studies. Our observation shows that mutations in both TG alleles were found in 27 families (9 as homozygote and 18 as heterozygote compound), whereas in the remaining four families only one mutated allele was detected. The majority of the detected mutations occur in exons 4, 7, 38 and 40. 28 different mutations were identified, 33 of the 96 TG alleles encoded the change p.R277*. In conclusion, our results confirm the genetic heterogeneity of TG defects and the pathophysiological importance of the predicted TG misfolding and therefore thyroid hormone formation as a consequence of truncated TG proteins and/or missense mutations located within its ACHE-like domain.
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Affiliation(s)
- Sofia Siffo
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Ezequiela Adrover
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Cintia E Citterio
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Mirta B Miras
- Servicio de Endocrinología, Hospital de Niños Santísima Trinidad, Córdoba, Argentina
| | - Viviana A Balbi
- Servicio de Endocrinología, Hospital de Niños "Sor María Ludovica", La Plata, Argentina
| | - Ana Chiesa
- Centro de Investigaciones Endocrinológicas, CEDIE-CONICET, División Endocrinología, Hospital de Niños "Ricardo Gutiérrez", Buenos Aires, Argentina
| | - Jacques Weill
- Clinique de Pédiatrie, Hôpital Jeanne de Flandre, Centre Hospitalier Regional Universitaire de Lille, Lille, France
| | - Gabriela Sobrero
- Servicio de Endocrinología, Hospital de Niños Santísima Trinidad, Córdoba, Argentina
| | - Verónica G González
- Servicio de Endocrinología, Hospital de Niños "Sor María Ludovica", La Plata, Argentina
| | - Patricia Papendieck
- Centro de Investigaciones Endocrinológicas, CEDIE-CONICET, División Endocrinología, Hospital de Niños "Ricardo Gutiérrez", Buenos Aires, Argentina
| | - Elena Bueno Martinez
- Unidad de Medicina Molecular-Departamento de Medicina, IBMCC and IBSAL, Universidad de Salamanca-CSIC, Salamanca, Spain
| | - Rogelio Gonzalez-Sarmiento
- Unidad de Medicina Molecular-Departamento de Medicina, IBMCC and IBSAL, Universidad de Salamanca-CSIC, Salamanca, Spain
| | - Carina M Rivolta
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Héctor M Targovnik
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina.
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18
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Citterio CE, Morishita Y, Dakka N, Veluswamy B, Arvan P. Relationship between the dimerization of thyroglobulin and its ability to form triiodothyronine. J Biol Chem 2018; 293:4860-4869. [PMID: 29440273 DOI: 10.1074/jbc.ra118.001786] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2018] [Revised: 02/06/2018] [Indexed: 01/23/2023] Open
Abstract
Thyroglobulin (TG) is the most abundant thyroid gland protein, a dimeric iodoglycoprotein (660 kDa). TG serves as the protein precursor in the synthesis of thyroid hormones tetraiodothyronine (T4) and triiodothyronine (T3). The primary site for T3 synthesis in TG involves an iodotyrosine acceptor at the antepenultimate Tyr residue (at the extreme carboxyl terminus of the protein). The carboxyl-terminal region of TG comprises a cholinesterase-like (ChEL) domain followed by a short unique tail sequence. Despite many studies, the monoiodotyrosine donor residue needed for the coupling reaction to create T3 at this evolutionarily conserved site remains unidentified. In this report, we have utilized a novel, convenient immunoblotting assay to detect T3 formation after protein iodination in vitro, enabling the study of T3 formation in recombinant TG secreted from thyrocytes or heterologous cells. With this assay, we confirm the antepenultimate residue of TG as a major T3-forming site, but also demonstrate that the side chain of this residue intimately interacts with the same residue in the apposed monomer of the TG dimer. T3 formation in TG, or the isolated carboxyl-terminal region, is inhibited by mutation of this antepenultimate residue, but we describe the first substitution mutation that actually increases T3 hormonogenesis by engineering a novel cysteine, 10 residues upstream of the antepenultimate residue, allowing for covalent association of the unique tail sequences, and that helps to bring residues Tyr2744 from apposed monomers into closer proximity.
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Affiliation(s)
- Cintia E Citterio
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105; Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología y Biotecnología/Cátedra de Genética, Buenos Aires C1113AAD, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires C1120AAR, Argentina
| | - Yoshiaki Morishita
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105
| | - Nada Dakka
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105
| | - Balaji Veluswamy
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105
| | - Peter Arvan
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105.
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19
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Bourne Y, Marchot P. Hot Spots for Protein Partnerships at the Surface of Cholinesterases and Related α/β Hydrolase Fold Proteins or Domains-A Structural Perspective. Molecules 2017; 23:molecules23010035. [PMID: 29295471 PMCID: PMC5943944 DOI: 10.3390/molecules23010035] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 12/21/2017] [Accepted: 12/21/2017] [Indexed: 12/12/2022] Open
Abstract
The hydrolytic enzymes acetyl- and butyryl-cholinesterase, the cell adhesion molecules neuroligins, and the hormonogenic macromolecule thyroglobulin are a few of the many members of the α/β hydrolase fold superfamily of proteins. Despite their distinctive functions, their canonical subunits, with a molecular surface area of ~20,000 Å2, they share binding patches and determinants for forming homodimers and for accommodating structural subunits or protein partners. Several of these surface regions of high functional relevance have been mapped through structural or mutational studies, while others have been proposed based on biochemical data or molecular docking studies. Here, we review these binding interfaces and emphasize their specificity versus potentially multifunctional character.
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Affiliation(s)
- Yves Bourne
- Centre National de la Recherche Scientifique, Aix-Marseille Université, "Architecture et Fonction des Macromolécules Biologiques" Laboratory, 13288 Marseille, France.
| | - Pascale Marchot
- Centre National de la Recherche Scientifique, Aix-Marseille Université, "Architecture et Fonction des Macromolécules Biologiques" Laboratory, 13288 Marseille, France.
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20
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Abstract
While some autoimmune disorders remain extremely rare, others largely predominate the epidemiology of human autoimmunity. Notably, these include psoriasis, diabetes, vitiligo, thyroiditis, rheumatoid arthritis and multiple sclerosis. Thus, despite the quasi-infinite number of "self" antigens that could theoretically trigger autoimmune responses, only a limited set of antigens, referred here as superautoantigens, induce pathogenic adaptive responses. Several lines of evidence reviewed in this paper indicate that, irrespective of the targeted organ (e.g. thyroid, pancreas, joints, brain or skin), a significant proportion of superautoantigens are highly expressed in the synaptic compartment of the central nervous system (CNS). Such an observation applies notably for GAD65, AchR, ribonucleoproteins, heat shock proteins, collagen IV, laminin, tyrosine hydroxylase and the acetylcholinesterase domain of thyroglobulin. It is also argued that cognitive alterations have been described in a number of autoimmune disorders, including psoriasis, rheumatoid arthritis, lupus, Crohn's disease and autoimmune thyroiditis. Finally, the present paper points out that a great majority of the "incidental" autoimmune conditions notably triggered by neoplasms, vaccinations or microbial infections are targeting the synaptic or myelin compartments. On this basis, the concept of an immunological homunculus, proposed by Irun Cohen more than 25 years ago, is extended here in a model where physiological autoimmunity against brain superautoantigens confers both: i) a crucial evolutionary-determined advantage via cognition-promoting autoimmunity; and ii) a major evolutionary-determined vulnerability, leading to the emergence of autoimmune disorders in Homo sapiens. Moreover, in this theoretical framework, the so called co-development/co-evolution model, both the development (at the scale of an individual) and evolution (at the scale of species) of the antibody and T-cell repertoires are coupled to those of the neural repertoires (i.e. the distinct neuronal populations and synaptic circuits supporting cognitive and sensorimotor functions). Clinical implications and future experimental insights are also presented and discussed.
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Affiliation(s)
- Serge Nataf
- Bank of Tissues and Cells, Lyon University Hospital (Hospices Civils de Lyon), CarMeN Laboratory, INSERM 1060, INRA 1397, INSA Lyon, Université Claude Bernard Lyon-1, Lyon, F-69000, France
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21
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Abstract
Thyroglobulin (Tg) is a vertebrate secretory protein synthesized in the thyrocyte endoplasmic reticulum (ER), where it acquires N-linked glycosylation and conformational maturation (including formation of many disulfide bonds), leading to homodimerization. Its primary functions include iodide storage and thyroid hormonogenesis. Tg consists largely of repeating domains, and many tyrosyl residues in these domains become iodinated to form monoiodo- and diiodotyrosine, whereas only a small portion of Tg structure is dedicated to hormone formation. Interestingly, evolutionary ancestors, dependent upon thyroid hormone for development, synthesize thyroid hormones without the complete Tg protein architecture. Nevertheless, in all vertebrates, Tg follows a strict pattern of region I, II-III, and the cholinesterase-like (ChEL) domain. In vertebrates, Tg first undergoes intracellular transport through the secretory pathway, which requires the assistance of thyrocyte ER chaperones and oxidoreductases, as well as coordination of distinct regions of Tg, to achieve a native conformation. Curiously, regions II-III and ChEL behave as fully independent folding units that could function as successful secretory proteins by themselves. However, the large Tg region I (bearing the primary T4-forming site) is incompetent by itself for intracellular transport, requiring the downstream regions II-III and ChEL to complete its folding. A combination of nonsense mutations, frameshift mutations, splice site mutations, and missense mutations in Tg occurs spontaneously to cause congenital hypothyroidism and thyroidal ER stress. These Tg mutants are unable to achieve a native conformation within the ER, interfering with the efficiency of Tg maturation and export to the thyroid follicle lumen for iodide storage and hormonogenesis.
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Affiliation(s)
- Bruno Di Jeso
- Laboratorio di Patologia Generale (B.D.J.), Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, 73100 Lecce, Italy; and Division of Metabolism, Endocrinology, and Diabetes (P.A.), University of Michigan Medical School, Ann Arbor, Michigan 48105
| | - Peter Arvan
- Laboratorio di Patologia Generale (B.D.J.), Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, 73100 Lecce, Italy; and Division of Metabolism, Endocrinology, and Diabetes (P.A.), University of Michigan Medical School, Ann Arbor, Michigan 48105
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22
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Le SN, Porebski BT, McCoey J, Fodor J, Riley B, Godlewska M, Góra M, Czarnocka B, Banga JP, Hoke DE, Kass I, Buckle AM. Modelling of Thyroid Peroxidase Reveals Insights into Its Enzyme Function and Autoantigenicity. PLoS One 2015; 10:e0142615. [PMID: 26623656 PMCID: PMC4666655 DOI: 10.1371/journal.pone.0142615] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 10/23/2015] [Indexed: 11/18/2022] Open
Abstract
Thyroid peroxidase (TPO) catalyses the biosynthesis of thyroid hormones and is a major autoantigen in Hashimoto's disease--the most common organ-specific autoimmune disease. Epitope mapping studies have shown that the autoimmune response to TPO is directed mainly at two surface regions on the molecule: immunodominant regions A and B (IDR-A, and IDR-B). TPO has been a major target for structural studies for over 20 years; however, to date, the structure of TPO remains to be determined. We have used a molecular modelling approach to investigate plausible modes of TPO structure and dimer organisation. Sequence features of the C-terminus are consistent with a coiled-coil dimerization motif that most likely anchors the TPO dimer in the apical membrane of thyroid follicular cells. Two contrasting models of TPO were produced, differing in the orientation and exposure of their active sites relative to the membrane. Both models are equally plausible based upon the known enzymatic function of TPO. The "trans" model places IDR-B on the membrane-facing side of the myeloperoxidase (MPO)-like domain, potentially hindering access of autoantibodies, necessitating considerable conformational change, and perhaps even dissociation of the dimer into monomers. IDR-A spans MPO- and CCP-like domains and is relatively fragmented compared to IDR-B, therefore most likely requiring domain rearrangements in order to coalesce into one compact epitope. Less epitope fragmentation and higher solvent accessibility of the "cis" model favours it slightly over the "trans" model. Here, IDR-B clusters towards the surface of the MPO-like domain facing the thyroid follicular lumen preventing steric hindrance of autoantibodies. However, conformational rearrangements may still be necessary to allow full engagement with autoantibodies, with IDR-B on both models being close to the dimer interface. Taken together, the modelling highlights the need to consider the oligomeric state of TPO, its conformational properties, and its proximity to the membrane, when interpreting epitope-mapping data.
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Affiliation(s)
- Sarah N. Le
- Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, Australia
| | - Benjamin T. Porebski
- Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, Australia
| | - Julia McCoey
- Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, Australia
| | - James Fodor
- Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, Australia
| | - Blake Riley
- Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, Australia
| | - Marlena Godlewska
- The Centre of Postgraduate Medical Education, Department of Biochemistry and Molecular Biology, Warsaw, Poland
| | - Monika Góra
- Institute of Biochemistry and Biophysics PAS, Department of Genetics, Warsaw, Poland
| | - Barbara Czarnocka
- The Centre of Postgraduate Medical Education, Department of Biochemistry and Molecular Biology, Warsaw, Poland
| | - J Paul Banga
- King's College London School of Medicine, Division of Diabetes and Nutrition Sciences, London, United Kingdom
| | - David E. Hoke
- Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, Australia
| | - Itamar Kass
- Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, Australia
- * E-mail: (AMB); (IK)
| | - Ashley M. Buckle
- Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, Australia
- * E-mail: (AMB); (IK)
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23
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Citterio CE, Morales CM, Bouhours-Nouet N, Machiavelli GA, Bueno E, Gatelais F, Coutant R, González-Sarmiento R, Rivolta CM, Targovnik HM. Novel compound heterozygous Thyroglobulin mutations c.745+1G>A/c.7036+2T>A associated with congenital goiter and hypothyroidism in a Vietnamese family. Identification of a new cryptic 5' splice site in the exon 6. Mol Cell Endocrinol 2015; 404:102-12. [PMID: 25633667 DOI: 10.1016/j.mce.2015.01.032] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2014] [Revised: 12/17/2014] [Accepted: 01/21/2015] [Indexed: 10/24/2022]
Abstract
Several patients were identified with dyshormonogenesis caused by mutations in the thyroglobulin (TG) gene. These defects are inherited in an autosomal recessive manner and affected individuals are either homozygous or compound heterozygous for the mutations. The aim of the present study was to identify new TG mutations in a patient of Vietnamese origin affected by congenital hypothyroidism, goiter and low levels of serum TG. DNA sequencing identified the presence of compound heterozygous mutations in the TG gene: the maternal mutation consists of a novel c.745+1G>A (g.IVS6 + 1G>A), whereas the hypothetical paternal mutation consists of a novel c.7036+2T>A (g.IVS40 + 2T>A). The father was not available for segregation analysis. Ex-vivo splicing assays and subsequent RT-PCR analyses were performed on mRNA isolated from the eukaryotic-cells transfected with normal and mutant expression vectors. Minigene analysis of the c.745+1G>A mutant showed that the exon 6 is skipped during pre-mRNA splicing or partially included by use of a cryptic 5' splice site located to 55 nucleotides upstream of the authentic exon 6/intron 6 junction site. The functional analysis of c.7036+2T>A mutation showed a complete skipping of exon 40. The theoretical consequences of splice site mutations, predicted with the bioinformatics tool NNSplice, Fsplice, SPL, SPLM and MaxEntScan programs were investigated and evaluated in relation with the experimental evidence. These analyses predicted that both mutant alleles would result in the abolition of the authentic splice donor sites. The c.745+1G>A mutation originates two putative truncated proteins of 200 and 1142 amino acids, whereas c.7036+2T>A mutation results in a putative truncated protein of 2277 amino acids. In conclusion, we show that the c.745+1G>A mutation promotes the activation of a new cryptic donor splice site in the exon 6 of the TG gene. The functional consequences of these mutations could be structural changes in the protein molecule that alter the biosynthesis of thyroid hormones.
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Affiliation(s)
- Cintia E Citterio
- Laboratorio de Genética y Biología Molecular, Instituto de Inmunología, Genética y Metabolismo (INIGEM, CONICET-UBA), Hospital de Clínicas "José de San Martín", C1120AAR Buenos Aires, Argentina; Cátedra de Genética y Biología Molecular (FFyB-UBA), C1113AAD Buenos Aires, Argentina
| | - Cecilia M Morales
- Laboratorio de Genética y Biología Molecular, Instituto de Inmunología, Genética y Metabolismo (INIGEM, CONICET-UBA), Hospital de Clínicas "José de San Martín", C1120AAR Buenos Aires, Argentina; Cátedra de Genética y Biología Molecular (FFyB-UBA), C1113AAD Buenos Aires, Argentina
| | - Natacha Bouhours-Nouet
- Unité Endocrinologie Diabétologie Pédiatrique and Centre des Maladies Rares de la Réceptivité Hormonale, CHU-Angers, 49933 Angers CEDEX 9, France
| | - Gloria A Machiavelli
- Laboratorio de Genética y Biología Molecular, Instituto de Inmunología, Genética y Metabolismo (INIGEM, CONICET-UBA), Hospital de Clínicas "José de San Martín", C1120AAR Buenos Aires, Argentina; Cátedra de Genética y Biología Molecular (FFyB-UBA), C1113AAD Buenos Aires, Argentina
| | - Elena Bueno
- Unidad de Medicina Molecular, Departamento de Medicina, Facultad de Medicina, Universidad de Salamanca, 37007 Salamanca, España
| | - Frédérique Gatelais
- Unité Endocrinologie Diabétologie Pédiatrique and Centre des Maladies Rares de la Réceptivité Hormonale, CHU-Angers, 49933 Angers CEDEX 9, France
| | - Regis Coutant
- Unité Endocrinologie Diabétologie Pédiatrique and Centre des Maladies Rares de la Réceptivité Hormonale, CHU-Angers, 49933 Angers CEDEX 9, France
| | - Rogelio González-Sarmiento
- Unidad de Medicina Molecular, Departamento de Medicina, Facultad de Medicina, Universidad de Salamanca, 37007 Salamanca, España
| | - Carina M Rivolta
- Laboratorio de Genética y Biología Molecular, Instituto de Inmunología, Genética y Metabolismo (INIGEM, CONICET-UBA), Hospital de Clínicas "José de San Martín", C1120AAR Buenos Aires, Argentina; Cátedra de Genética y Biología Molecular (FFyB-UBA), C1113AAD Buenos Aires, Argentina; Unidad de Medicina Molecular, Departamento de Medicina, Facultad de Medicina, Universidad de Salamanca, 37007 Salamanca, España
| | - Héctor M Targovnik
- Laboratorio de Genética y Biología Molecular, Instituto de Inmunología, Genética y Metabolismo (INIGEM, CONICET-UBA), Hospital de Clínicas "José de San Martín", C1120AAR Buenos Aires, Argentina; Cátedra de Genética y Biología Molecular (FFyB-UBA), C1113AAD Buenos Aires, Argentina; Unidad de Medicina Molecular, Departamento de Medicina, Facultad de Medicina, Universidad de Salamanca, 37007 Salamanca, España.
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24
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Di Jeso B, Morishita Y, Treglia AS, Lofrumento DD, Nicolardi G, Beguinot F, Kellogg AP, Arvan P. Transient covalent interactions of newly synthesized thyroglobulin with oxidoreductases of the endoplasmic reticulum. J Biol Chem 2014; 289:11488-11496. [PMID: 24599957 DOI: 10.1074/jbc.m113.520767] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Newly synthesized thyroglobulin (Tg), the thyroid prohormone, forms detectable high molecular weight mixed disulfide adducts: until now, only Tg "adduct B" was identified as primarily engaging the endoplasmic reticulum oxidoreductases ERp57 and protein disulfide isomerase. Here, we demonstrate that the faster migrating Tg adduct C primarily engages the CaBP1/P5 oxidoreductase, whereas the slower migrating Tg adduct A primarily engages ERp72. Upon siRNA-mediated knockdown of CaBP1/P5 or ERp72, adducts C or A, respectively, are decreased. Within the three Tg adduct bands that do not exhibit a precursor-product relationship, Tg exhibits distinct oxidation patterns. We present evidence suggesting that disulfide maturation occurs within Tg monomers engaged in each of the adduct bands. Moreover, the same Tg substrate molecules can form simultaneous mixed disulfides with both CaBP1/P5 and protein disulfide isomerase, although these are generally viewed as components of distinct oxidoreductase-chaperone protein complexes. Such substrate-oxidoreductase combinations offer Tg the potential for simultaneous oxidative maturation along different parallel tracks leading to the native state.
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Affiliation(s)
- Bruno Di Jeso
- Laboratorio di Patologia Generale, Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, 73100 Lecce, Italy,.
| | - Yoshiaki Morishita
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105
| | - Antonella S Treglia
- Laboratorio di Patologia Generale, Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, 73100 Lecce, Italy
| | - Dario D Lofrumento
- Laboratorio di Anatomia Umana, Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Universita' del Salento, 73100 Lecce, Italy, and
| | - Giuseppe Nicolardi
- Laboratorio di Anatomia Umana, Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Universita' del Salento, 73100 Lecce, Italy, and
| | - Francesco Beguinot
- Dipartimento di Scienze Mediche Traslazionali e Istituto di Endocrinologia ed Oncologia Sperimentale, Centro Nazionale delle Ricerche, Università Federico II, 80131 Napoli, Italy
| | - Aaron P Kellogg
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105
| | - Peter Arvan
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105,.
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25
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Citterio CE, Rossetti LC, Souchon PF, Morales C, Thouvard-Viprey M, Salmon-Musial AS, Mauran PLA, Doco-Fenzy M, González-Sarmiento R, Rivolta CM, De Brasi CD, Targovnik HM. Novel mutational mechanism in the thyroglobulin gene: imperfect DNA inversion as a cause for hereditary hypothyroidism. Mol Cell Endocrinol 2013; 381:220-9. [PMID: 23933148 DOI: 10.1016/j.mce.2013.07.034] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2013] [Revised: 07/21/2013] [Accepted: 07/31/2013] [Indexed: 10/26/2022]
Abstract
The objective of this study was to perform genetic analysis in three brothers of Turkish origin born from consanguineus parents and affected by congenital hypothyroidism, goiter and low levels of serum TG. The combination of sequencing of DNA, PCR mapping, quantitative real-time PCR, inverse-PCR (I-PCR), multiplex PCR and bioinformatics analysis were used in order to detect TG mutations. We demonstrated that the three affected siblings are homozygous for a DNA inversion of 16,962bp in the TG gene associated with two deleted regions at both sides of the inversion limits. The inversion region includes the first 9bp of exon 48, 1015bp of intron 47, 191bp of exon 47, 1523bp of intron 46, 135bp of exon 46 and the last 14,089bp of intron 45. The proximal deletion corresponds to 27bp of TG intron 45, while the distal deletion spans the last 230bp of TG exon 48 and the first 588bp of intergenic region downstream TG end. The parents were heterozygous carriers of the complex rearrangement. In conclusion, a novel large imperfect DNA inversion within the TG gene was identified by the strategy of I-PCR. This aberration was not detectable by normal sequencing of the exons and exon/intron boundaries. Remarkably, the finding represents the first description of a TG deficiency disease caused by a DNA inversion.
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Affiliation(s)
- Cintia E Citterio
- Laboratorio de Genética y Biología Molecular, Instituto de Inmunología, Genética y Metabolismo (INIGEM, CONICET-UBA), Hospital de Clínicas "José de San Martín", C1120AAR Buenos Aires, Argentina; Cátedra de Genética y Biología Molecular (FFyB-UBA), C1113AAD Buenos Aires, Argentina
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Molecular Assembly of Thyroglobulin Induced by In Vitro Nitric Oxide Treatments: Implication Its Role in Thyroid Cells. Protein J 2013; 32:619-25. [DOI: 10.1007/s10930-013-9524-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Gualeni B, Rajpar MH, Kellogg A, Bell PA, Arvan P, Boot-Handford RP, Briggs MD. A novel transgenic mouse model of growth plate dysplasia reveals that decreased chondrocyte proliferation due to chronic ER stress is a key factor in reduced bone growth. Dis Model Mech 2013; 6:1414-25. [PMID: 24046357 PMCID: PMC3820264 DOI: 10.1242/dmm.013342] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Accepted: 09/05/2013] [Indexed: 01/09/2023] Open
Abstract
Disease mechanisms leading to different forms of chondrodysplasia include extracellular matrix (ECM) alterations and intracellular stress resulting in abnormal changes to chondrocyte proliferation and survival. Delineating the relative contribution of these two disease mechanisms is a major challenge in understanding disease pathophysiology in genetic skeletal diseases and a prerequisite for developing effective therapies. To determine the influence of intracellular stress and changes in chondrocyte phenotype to the development of chondrodysplasia, we targeted the expression of the G2320R mutant form of thyroglobulin to the endoplasmic reticulum (ER) of resting and proliferating chondrocytes. Previous studies on this mutant protein have shown that it induces intracellular aggregates and causes cell stress and death in the thyroid gland. The expression and retention of this exogenous mutant protein in resting and proliferating chondrocytes resulted in a chronic cell stress response, growth plate dysplasia and reduced bone growth, without inducing any alterations to the architecture and organization of the cartilage ECM. More significantly, the decreased bone growth seemed to be the direct result of reduced chondrocyte proliferation in the proliferative zone of growth plates in transgenic mice, without transcriptional activation of a classical unfolded protein response (UPR) or apoptosis. Overall, these data show that mutant protein retention in the ER of resting and proliferative zone chondrocytes is sufficient to cause disrupted bone growth. The specific disease pathways triggered by mutant protein retention do not necessarily involve a prototypic UPR, but all pathways impact upon chondrocyte proliferation in the cartilage growth plate.
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Affiliation(s)
- Benedetta Gualeni
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Manchester, M13 9PT, UK
| | - M. Helen Rajpar
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Manchester, M13 9PT, UK
| | - Aaron Kellogg
- University of Michigan Health System, Ann Arbor, MI 48109, USA
| | - Peter A. Bell
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Manchester, M13 9PT, UK
| | - Peter Arvan
- University of Michigan Health System, Ann Arbor, MI 48109, USA
| | - Raymond P. Boot-Handford
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Manchester, M13 9PT, UK
| | - Michael D. Briggs
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Manchester, M13 9PT, UK
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Agretti P, De Marco G, Di Cosmo C, Ferrarini E, Montanelli L, Bagattini B, Vitti P, Tonacchera M. Congenital hypothyroidism caused by a novel homozygous mutation in the thyroglobulin gene. Eur J Pediatr 2013; 172:959-64. [PMID: 23455760 DOI: 10.1007/s00431-013-1976-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Revised: 02/07/2013] [Accepted: 02/12/2013] [Indexed: 12/28/2022]
Abstract
UNLABELLED Congenital hypothyroidism (CH) due to thyroglobulin (TG) deficit is an autosomal recessive disease (OMIM #274700) characterized by hypothyroidism, goiter, low serum TG, and a negative perchlorate discharge test. The aim of this study was to perform the genetic analysis of the TG gene in two sisters born from consanguineus parents and affected by CH and low serum TG levels. The index patient and her sister were identified at neonatal screening for CH and treated with L-thyroxine (L-T4). After discontinuation of L-T4 therapy, hypothyroidism was confirmed, serum TG was undetectable, and no organification defect after (123)I scintigraphy and perchlorate test was shown; thyroid ultrasound showed a eutopic gland of normal size. DNA was extracted from peripheral white blood cells of the two sisters and the father. All 48 exons of TG gene were amplified by polymerase chain reaction and subjected to direct sequencing. A novel homozygous point mutation in exon 10 of TG gene was identified in the patient and her sister. The mutation determined a stop codon at position 768 (R768X) resulting in an early truncated protein or in the complete absence of the protein. The father (euthyroid) was heterozygous carrier of the mutation. CONCLUSION Genetic analysis of TG gene was performed in two sisters affected by CH. A novel point mutation of the TG gene determining a stop codon at position 768 of the protein was identified. The early truncated nonfunctioning protein or the absence of the protein due to the premature degradation of abnormal mRNA may be responsible of the observed phenotype.
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Affiliation(s)
- Patrizia Agretti
- Dipartimento di Medicina Clinica e Sperimentale, Sezione di Endocrinologia, Università di Pisa, Azienda Ospedaliero-Universitaria Pisana, Pisa, Italy
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Wright J, Wang X, Haataja L, Kellogg AP, Lee J, Liu M, Arvan P. Dominant protein interactions that influence the pathogenesis of conformational diseases. J Clin Invest 2013; 123:3124-34. [PMID: 23722904 DOI: 10.1172/jci67260] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Accepted: 03/28/2013] [Indexed: 02/06/2023] Open
Abstract
Misfolding of exportable proteins can trigger endocrinopathies. For example, misfolding of insulin can result in autosomal dominant mutant INS gene-induced diabetes of youth, and misfolding of thyroglobulin can result in autosomal recessive congenital hypothyroidism with deficient thyroglobulin. Both proinsulin and thyroglobulin normally form homodimers; the mutant versions of both proteins misfold in the ER, triggering ER stress, and, in both cases, heterozygosity creates potential for cross-dimerization between mutant and WT gene products. Here, we investigated these two ER-retained mutant secretory proteins and the selectivity of their interactions with their respective WT counterparts. In both cases and in animal models of these diseases, we found that conditions favoring an increased stoichiometry of mutant gene product dominantly inhibited export of the WT partner, while increased relative level of the WT gene product helped to rescue secretion of the mutant partner. Surprisingly, the bidirectional consequences of secretory blockade and rescue occur simultaneously in the same cells. Thus, in the context of heterozygosity, expression level and stability of WT subunits may be a critical factor influencing the effect of protein misfolding on clinical phenotype. These results offer new insight into dominant as well as recessive inheritance of conformational diseases and offer opportunities for the development of new therapies.
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Affiliation(s)
- Jordan Wright
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical Center, Ann Arbor, Michigan, USA
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Colin IM, Denef JF, Lengelé B, Many MC, Gérard AC. Recent insights into the cell biology of thyroid angiofollicular units. Endocr Rev 2013; 34:209-38. [PMID: 23349248 PMCID: PMC3610675 DOI: 10.1210/er.2012-1015] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Accepted: 11/07/2012] [Indexed: 01/06/2023]
Abstract
In thyrocytes, cell polarity is of crucial importance for proper thyroid function. Many intrinsic mechanisms of self-regulation control how the key players involved in thyroid hormone (TH) biosynthesis interact in apical microvilli, so that hazardous biochemical processes may occur without detriment to the cell. In some pathological conditions, this enzymatic complex is disrupted, with some components abnormally activated into the cytoplasm, which can lead to further morphological and functional breakdown. When iodine intake is altered, autoregulatory mechanisms outside the thyrocytes are activated. They involve adjacent capillaries that, together with thyrocytes, form the angiofollicular units (AFUs) that can be considered as the functional and morphological units of the thyroid. In response to iodine shortage, a rapid expansion of the microvasculature occurs, which, in addition to nutrients and oxygen, optimizes iodide supply. These changes are triggered by angiogenic signals released from thyrocytes via a reactive oxygen species/hypoxia-inducible factor/vascular endothelial growth factor pathway. When intra- and extrathyrocyte autoregulation fails, other forms of adaptation arise, such as euthyroid goiters. From onset, goiters are morphologically and functionally heterogeneous due to the polyclonal nature of the cells, with nodules distributed around areas of quiescent AFUs containing globules of compact thyroglobulin (Tg) and surrounded by a hypotrophic microvasculature. Upon TSH stimulation, quiescent AFUs are activated with Tg globules undergoing fragmentation into soluble Tg, proteins involved in TH biosynthesis being expressed and the local microvascular network extending. Over time and depending on physiological needs, AFUs may undergo repetitive phases of high, moderate, or low cell and tissue activity, which may ultimately culminate in multinodular goiters.
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Affiliation(s)
- Ides M Colin
- Pôle de Morphologie, Institut de Recherche Expérimentale et Clinique, Secteur des Sciences de la Santé, Université Catholique de Louvain (UCL), UCL-5251, 52 Avenue E. Mounier, B-1200, Bruxelles, Belgium.
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Citterio CE, Machiavelli GA, Miras MB, Gruñeiro-Papendieck L, Lachlan K, Sobrero G, Chiesa A, Walker J, Muñoz L, Testa G, Belforte FS, González-Sarmiento R, Rivolta CM, Targovnik HM. New insights into thyroglobulin gene: molecular analysis of seven novel mutations associated with goiter and hypothyroidism. Mol Cell Endocrinol 2013; 365:277-91. [PMID: 23164529 DOI: 10.1016/j.mce.2012.11.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2012] [Revised: 10/25/2012] [Accepted: 11/05/2012] [Indexed: 11/21/2022]
Abstract
The thyroglobulin (TG) gene is organized in 48 exons, spanning over 270 kb on human chromosome 8q24. Up to now, 62 inactivating mutations in the TG gene have been identified in patients with congenital goiter and endemic or non-endemic simple goiter. The purpose of the present study was to identify and characterize new mutations in the TG gene. We report 13 patients from seven unrelated families with goiter, hypothyroidism and low levels of serum TG. All patients underwent clinical, biochemical and imaging evaluation. Single-strand conformation polymorphism (SSCP) analysis, endonuclease restriction analysis, sequencing of DNA, genotyping, population screening, and bioinformatics studies were performed. Molecular analyses revealed seven novel inactivating TG mutations: c.378C>A [p.Y107X], c.2359C>T [p.R768X], c.2736delG [p.R893fsX946], c.3842G>A [p.C1262Y], c.5466delA [p.K1803fsX1833], c.6000C>G [p.C1981W] and c.6605C>G [p.P2183R] and three previously reported mutations: c.886C>T [p.R277X], c.6701C>A [p.A2215D] and c.7006C>T [p.R2317X]. Six patients from two families were homozygous for p.R277X mutation, four were compound heterozygous mutations (p.Y107X/p.C1262Y, p.R893fsX946/p.A2215D, p.K1803fsX1832/p.R2317X), one carried three identified mutations (p.R277X/p.C1981W-p.P2183R) together with a hypothetical micro deletion and the remaining two siblings from another family with typical phenotype had a single p.R768X mutated allele. In conclusion, our results confirm the genetic heterogeneity of TG defects and the pathophysiological importance of altered TG folding as a consequency of truncated TG proteins and missense mutations located in ACHE-like domain or that replace cysteine.
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Affiliation(s)
- Cintia E Citterio
- Laboratorio de Genética y Biología Molecular, Instituto de Inmunología, Genética y Metabolismo, Hospital de Clínicas José de San Martín, C1120AAR Buenos Aires, Argentina
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De Jaco A, Dubi N, Camp S, Taylor P. Congenital hypothyroidism mutations affect common folding and trafficking in the α/β-hydrolase fold proteins. FEBS J 2012; 279:4293-305. [PMID: 23035660 DOI: 10.1111/febs.12019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Revised: 09/27/2012] [Accepted: 09/28/2012] [Indexed: 12/19/2022]
Abstract
The α/β-hydrolase fold superfamily of proteins is composed of structurally related members that, despite great diversity in their catalytic, recognition, adhesion and chaperone functions, share a common fold governed by homologous residues and conserved disulfide bridges. Non-synonymous single nucleotide polymorphisms within the α/β-hydrolase fold domain in various family members have been found for congenital endocrine, metabolic and nervous system disorders. By examining the amino acid sequence from the various proteins, mutations were found to be prevalent in conserved residues within the α/β-hydrolase fold of the homologous proteins. This is the case for the thyroglobulin mutations linked to congenital hypothyroidism. To address whether correct folding of the common domain is required for protein export, we inserted the thyroglobulin mutations at homologous positions in two correlated but simpler α/β-hydrolase fold proteins known to be exported to the cell surface: neuroligin3 and acetylcholinesterase. Here we show that these mutations in the cholinesterase homologous region alter the folding properties of the α/β-hydrolase fold domain, which are reflected in defects in protein trafficking, folding and function, and ultimately result in retention of the partially processed proteins in the endoplasmic reticulum. Accordingly, mutations at conserved residues may be transferred amongst homologous proteins to produce common processing defects despite disparate functions, protein complexity and tissue-specific expression of the homologous proteins. More importantly, a similar assembly of the α/β-hydrolase fold domain tertiary structure among homologous members of the superfamily is required for correct trafficking of the proteins to their final destination.
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Affiliation(s)
- Antonella De Jaco
- Department of Pharmacology, Skaggs School of Pharmacy & Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, USA.
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Belkadi A, Jacques C, Savagner F, Malthièry Y. Phylogenetic analysis of the human thyroglobulin regions. Thyroid Res 2012; 5:3. [PMID: 22549183 PMCID: PMC3464141 DOI: 10.1186/1756-6614-5-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Accepted: 05/01/2012] [Indexed: 02/02/2023] Open
Abstract
Thyroglobulin is a large protein present in all vertebrates. It is synthesized in the thyrocytes and exported to lumen of the thyroid follicle, where its tyrosine residues are iodinated . The iodinated thyroglobulin is reintegrated into the cell and processed (cleaved to free its two extremities) for thyroid hormone synthesis. Thyroglobulin sequence analysis has identified four regions of the molecule: Tg1, Tg2, Tg3 and ChEL. Structural abnormalities and mutations result in different pathological consequences, depending on the thyroglobulin region affected. We carried out a bioinformatic analysis of thyroglobulin, determining the origin and the function of each region. Our results suggest that the Tg1 region acts as a binding protein on the apical membrane, the Tg2 region is involved in protein adhesion and the Tg3 region is involved in determining the three-dimensional structure of the protein. The ChEL domain is involved in thyroglobulin transport, dimerization and adhesion. The presence of repetitive domains in the Tg1, Tg2 and Tg3 regions suggests that these domains may have arisen through duplication.
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Affiliation(s)
- Abdelaziz Belkadi
- INSERM U694, Institut Biologie Santé (IBS), rue des Capucins, F-49100 Angers, France.
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34
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Abstract
In vertebrates, the thyroglobulin (Tg) gene product must be exported to the lumen of thyroid follicles for thyroid hormone synthesis. In toto, Tg is composed of multiple type-1 repeats connected by linker and hinge (altogether considered as "region I," nearly 1,200 residues); regions II-III (~720 residues); and cholinesterase-like (ChEL) domain (~570 residues). Regions II-III and ChEL rapidly acquire competence for secretion, yet regions I-II-III require 20 min to become a partially mature disulfide isomer; stabilization of a fully oxidized form requires ChEL. Transition from partially mature to mature Tg occurs as a discrete "jump" in mobility by nonreducing SDS-PAGE, suggesting formation of at most a few final pairings of Cys residues that may be separated by significant intervening primary sequence. Using two independent approaches, we have investigated which portion of Tg is engaged in this late stage of its maturation. First, we demonstrate that this event is linked to oxidation involving region I. Introduction of the Tg-C1245R mutation in the hinge (identical to that causing human goitrous hypothyroidism) inhibits this maturation, although the Cys-1245 partner remains unidentified. Second, we find that Tg truncated after its fourth type-1 repeat is a fully independent secretory protein. Together, the data indicate that final acquisition of secretory competence includes conformational maturation in the interval between linker and hinge segments of region I.
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Affiliation(s)
- Jaemin Lee
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical Center, Ann Arbor, Michigan 48109, USA
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Abstract
Thyroglobulin (precursor for thyroid hormone synthesis) is a large secreted glycoprotein comprising contiguous region I (multiple type-1 repeating units engaging the first ∼1,191 residues, followed by a ∼245-residue hinge region), regions II-III (multiple type-2 and 3 repeating units, comprising ∼720 residues), and the C-terminal cholinesterase-like (ChEL) domain (∼570 residues). A signal peptide attached to ChEL makes an independent secretory protein that binds to I-II-III, stabilizing it and rescuing the secretion of I-II-III that would otherwise be trapped in the endoplasmic reticulum (ER). In this study, we found that a signal peptide attached to regions II-III also makes for an efficient secretory protein that neither demonstrably interacts nor has its secretion enhanced by the presence of secretory ChEL. By contrast, region I, either with or without the hinge region, cannot be secreted on its own and remains in the ER where it is bound to ER chaperones BiP and GRP94. Whereas ChEL can rescue secretion of I-II-III, it can rescue I-II only very weakly, and region I not at all. Yet, ChEL begins to rescue region I in cells that also co-express secretory II-III. The data suggest that conformational maturation of region I is a limiting step in the thyroglobulin maturation process, and this step is facilitated by the presence of both regions II-III and ChEL. Mutations causing hypothyroidism might induce solely local/regional misfolding or may interfere more globally by impeding interactions between regions that are required for thyroglobulin secretion.
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Affiliation(s)
- Jaemin Lee
- Division of Metabolism, Endocrinology, and Diabetes, the University of Michigan Medical Center, Ann Arbor, Michigan 48109-0678, USA
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Peteiro-Gonzalez D, Lee J, Rodriguez-Fontan J, Castro-Piedras I, Cameselle-Teijeiro J, Beiras A, Bravo SB, Alvarez CV, Hardy DM, Targovnik HM, Arvan P, Lado-Abeal J. New insights into thyroglobulin pathophysiology revealed by the study of a family with congenital goiter. J Clin Endocrinol Metab 2010; 95:3522-6. [PMID: 20410234 PMCID: PMC2928901 DOI: 10.1210/jc.2009-2109] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Thyroglobulin (TG) gene mutations cause congenital hypothyroidism (CH) with goiter. A founder effect has been proposed for some frequent mutations. Mutated proteins have a defect in intracellular transport causing intracellular retention with ultrastructural changes that resemble an endoplasmic reticulum storage disease. OBJECTIVE To reveal new aspects of thyroglobulin pathophysiology through clinical, cellular, molecular, and genetic studies in a family presenting with CH due to TG mutations from Galicia, an iodine-deficient area of Spain. DESIGN The included clinical evaluation of family members, DNA sequencing for TG gene mutation and haplotyping analysis, ultrastructural analysis of thyroid tissue specimens from affected subjects, analysis of effects of mutations found on TG gene transcription, and in vitro studies of cellular production and secretion of mutated proteins. SETTING Locations included primary care and university hospitals. RESULTS Family members with CH, mental retardation, and goiter were compound heterozygous for c.886C-->T (p.R277X) and g.IVS35+1delG. For c.886C-->T, a founder effect cannot be excluded, and its transcription was hardly detectable. g.IVS35+1delG caused an in-frame deletion in exon 35 and produced a protein that, although synthesized, could not be secreted. Ultrastructural analyses showed morphological changes consistent with an endoplasmic reticulum storage disease. CONCLUSION The shorter thyroglobulin resulting from the novel g.IVS35+1delG was retained within the endoplasmic reticulum of thyrocytes, and together with p.R227X caused severe hypothyroidism with goiter. p.R277X, the most commonly described TG mutation, is caused by a TG exon-7 highly mutation-prone region, and the possibility that some cases were introduced to South America from Galicia cannot be excluded.
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Affiliation(s)
- D Peteiro-Gonzalez
- Unidade de Enfermedades Tiroideas e Metabolicas, School of Medicine, University of Santiago de Compostela, E-15782 Spain
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Wang X, Lee J, Di Jeso B, Treglia AS, Comoletti D, Dubi N, Taylor P, Arvan P. Cis and trans actions of the cholinesterase-like domain within the thyroglobulin dimer. J Biol Chem 2010; 285:17564-73. [PMID: 20353937 PMCID: PMC2878521 DOI: 10.1074/jbc.m110.111641] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2010] [Revised: 03/26/2010] [Indexed: 11/06/2022] Open
Abstract
Thyroglobulin (Tg, precursor for thyroid hormone synthesis) is a large secreted glycoprotein composed of upstream regions I-II-III, followed by the approximately 570 residue cholinesterase-like (ChEL) domain. ChEL has two identified functions: 1) homodimerization, and 2) binding to I-II-III that facilitates I-II-III oxidative maturation required for intracellular protein transport. Like its homologs in the acetylcholinesterase (AChE) family, ChEL possesses two carboxyl-terminal alpha-helices. We find that a Tg-AChE chimera (swapping AChE in place of ChEL) allows for dimerization with monomeric AChE, proving exposure of the carboxyl-terminal helices within the larger context of Tg. Further, we establish that perturbing trans-helical interaction blocks homodimerization of the Tg ChEL domain. Additionally, ChEL can associate with neuroligins (a related family of cholinesterase-like proteins), demonstrating potential for Tg cross-dimerization between non-identical partners. Indeed, when mutant rdw-Tg (Tg-G2298R, defective for protein secretion) is co-expressed with wild-type Tg, the two proteins cross-dimerize and secretion of rdw-Tg is partially restored. Moreover, we find that AChE and soluble neuroligins also can bind to the upstream Tg regions I-II-III; however, they cannot rescue secretion, because they cannot facilitate oxidative maturation of I-II-III. These data suggest that specific properties of distinct Tg ChEL mutants may result in distinct patterns of Tg monomer folding, cross-dimerization with wild-type Tg, and variable secretion behavior in heterozygous patients.
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Affiliation(s)
- Xiaofan Wang
- From the Division of Metabolism, Endocrinology and Diabetes, and
| | - Jaemin Lee
- From the Division of Metabolism, Endocrinology and Diabetes, and
- Program of Cell and Molecular Biology, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0678
| | - Bruno Di Jeso
- the Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Facolta di Scienze MFN, Università degli Studi di Lecce, Strada Provincale Lecce-Monteroni, 73100 Lecce, Italy, and
| | - A. Sonia Treglia
- the Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Facolta di Scienze MFN, Università degli Studi di Lecce, Strada Provincale Lecce-Monteroni, 73100 Lecce, Italy, and
| | - Davide Comoletti
- the Department of Pharmacology, University of California San Diego, La Jolla, California 92093
| | - Noga Dubi
- the Department of Pharmacology, University of California San Diego, La Jolla, California 92093
| | - Palmer Taylor
- the Department of Pharmacology, University of California San Diego, La Jolla, California 92093
| | - Peter Arvan
- From the Division of Metabolism, Endocrinology and Diabetes, and
- Program of Cell and Molecular Biology, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0678
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