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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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Lofrumento DD, Miraglia A, La Pesa V, Treglia AS, Chieppa M, De Nuccio F, Nicolardi G, Miele C, Beguinot F, Garbi C, Di Jeso B. Increased hexosamine biosynthetic pathway flux alters cell-cell adhesion in INS-1E cells and murine islets. Endocrine 2023; 81:492-502. [PMID: 37306934 PMCID: PMC10403402 DOI: 10.1007/s12020-023-03412-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Accepted: 05/28/2023] [Indexed: 06/13/2023]
Abstract
PURPOSE In type 2 Diabetes, β-cell failure is caused by loss of cell mass, mostly by apoptosis, but also by simple dysfunction (dedifferentiation, decline of glucose-stimulated insulin secretion). Apoptosis and dysfunction are caused, at least in part, by glucotoxicity, in which increased flux of glucose in the hexosamine biosynthetic pathway plays a role. In this study, we sought to clarify whether increased hexosamine biosynthetic pathway flux affects another important aspect of β-cell physiology, that is β-cell-β-cell homotypic interactions. METHODS We used INS-1E cells and murine islets. The expression and cellular distribution of E-cadherin and β-catenin was evaluated by immunofluorescence, immunohistochemistry and western blot. Cell-cell adhesion was examined by the hanging-drop aggregation assay, islet architecture by isolation and microscopic observation. RESULTS E-cadherin expression was not changed by increased hexosamine biosynthetic pathway flux, however, there was a decrease of cell surface, and an increase in intracellular E-cadherin. Moreover, intracellular E-cadherin delocalized, at least in part, from the Golgi complex to the endoplasmic reticulum. Beta-catenin was found to parallel the E-cadherin redistribution, showing a dislocation from the plasmamembrane to the cytosol. These changes had as a phenotypic consequence a decreased ability of INS-1E to aggregate. Finally, in ex vivo experiments, glucosamine was able to alter islet structure and to decrease surface abundandance of E-cadherin and β-catenin. CONCLUSION Increased hexosamine biosynthetic pathway flux alters E-cadherin cellular localization both in INS-1E cells and murine islets and affects cell-cell adhesion and islet morphology. These changes are likely caused by alterations of E-cadherin function, highlighting a new potential target to counteract the consequences of glucotoxicity on β-cells.
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Affiliation(s)
| | - Alessandro Miraglia
- DiSTeBA, Centro Ecotekne, Strada Monteroni, University of Salento, 73100, Lecce, Italy
| | - Velia La Pesa
- Institute of Experimental Neurology and Division of Neuroscience, Neuropathology Unit, IRCCS San Raffaele Scientific Institute, 20132, Milan, Italy
| | | | - Marcello Chieppa
- DiSTeBA, Centro Ecotekne, Strada Monteroni, University of Salento, 73100, Lecce, Italy
| | - Francesco De Nuccio
- DiSTeBA, Centro Ecotekne, Strada Monteroni, University of Salento, 73100, Lecce, Italy
| | - Giuseppe Nicolardi
- DiSTeBA, Centro Ecotekne, Strada Monteroni, University of Salento, 73100, Lecce, Italy
| | - Claudia Miele
- CNR, IEOS and DiSMeT, Via S. Pansini 5, University "Federico II", Naples, Italy
| | - Francesco Beguinot
- CNR, IEOS and DiSMeT, Via S. Pansini 5, University "Federico II", Naples, Italy
| | - Corrado Garbi
- Dip. Medicina Molecolare e Biotecnologie Mediche, Via S. Pansini 5, University "Federico II", Naples, Italy
| | - Bruno Di Jeso
- DiSTeBA, Centro Ecotekne, Strada Monteroni, University of Salento, 73100, Lecce, Italy.
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3
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Liu R, Tian JL, Huang XL, Song YZ. Genetic Factors Causing Thyroid Dyshormonogenesis as the Major Etiologies for Primary Congenital Hypothyroidism: Clinical and Genetic Characterization of 33 Patients. J Clin Med 2022; 11:7313. [PMID: 36555929 PMCID: PMC9786654 DOI: 10.3390/jcm11247313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/01/2022] [Accepted: 12/07/2022] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND AND AIMS Although the significance of primary congenital hypothyroidism (CH) is supported by an increasing amount of evidence, the clinical and genetic characteristics of this condition are still poorly understood. This study aimed to explore the underlying genetic etiologies in a cohort of primary CH patients. SUBJECTS AND METHODS The clinical data of 33 patients with primary CH were collected and analyzed via a cross-sectional study. Genetic analysis was performed by high-throughput sequencing and Sanger verification, and the pathogenicity of the novel missense variants was predicted using a variety of comprehensive bioinformatic tools. RESULTS Among the 33 patients, 22 (22/33, 66.7%) harbored pathogenic variants in the causative genes of thyroid dysgenesis or dyshormonogenesis, with DUOX2 (15/33, 45.5%) topping the list, followed by TG, TPO, DUOXA2 and PAX8. Four novel genetic variants were detected, including a pathogenic frameshift and three likely pathogenic missense variants. Positive neonatal screening for TSH, neonatal jaundice and abnormal thyroid morphology were the main positive findings among all cases. Although 31 of the total 33 CH patients exhibited normal anthropometric and social performance, the other 2 had poor prognosis in this study. CONCLUSIONS This study reported 33 new CH patients bearing four novel genetic variants, which enriched the variant spectrum of CH genes. In this cohort, genetic factors causing thyroid dyshormonogenesis were the main etiologies of CH development. Most patients exhibited a favorable prognosis; however, systematic management remains a challenge in achieving improved clinical outcomes for CH patients.
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Affiliation(s)
- Rui Liu
- Department of Pediatrics, The First Affiliated Hospital, Jinan University, Guangzhou 510630, China
| | - Jing-Li Tian
- Department of Pediatrics, Huizhou No. 2 Women’s and Children’s Healthcare Hospital, Huizhou 516000, China
| | - Xiao-Ling Huang
- Neonatal Screening Center, Dongguan Maternal and Child Healthcare Hospital, Dongguan 523125, China
| | - Yuan-Zong Song
- Department of Pediatrics, The First Affiliated Hospital, Jinan University, Guangzhou 510630, China
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4
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Zhang X, Malik B, Young C, Zhang H, Larkin D, Liao XH, Refetoff S, Liu M, Arvan P. Maintaining the thyroid gland in mutant thyroglobulin-induced hypothyroidism requires thyroid cell proliferation that must continue in adulthood. J Biol Chem 2022; 298:102066. [PMID: 35618019 PMCID: PMC9213252 DOI: 10.1016/j.jbc.2022.102066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 05/17/2022] [Accepted: 05/18/2022] [Indexed: 11/14/2022] Open
Abstract
Congenital hypothyroidism with biallelic thyroglobulin (Tg protein, encoded by the TG gene) mutation is an endoplasmic reticulum (ER) storage disease. Many patients (and animal models) grow an enlarged thyroid (goiter), yet some do not. In adulthood, hypothyroid TGcog/cog mice (bearing a Tg-L2263P mutation) exhibit a large goiter, whereas adult WIC rats bearing the TGrdw/rdw mutation (Tg-G2298R) exhibit a hypoplastic thyroid. Homozygous TG mutation has been linked to thyroid cell death, and cytotoxicity of the Tg-G2298R protein was previously thought to explain the lack of goiter in WIC-TGrdw/rdw rats. However, recent studies revealed that TGcog/cog mice also exhibit widespread ER stress–mediated thyrocyte death, yet under continuous feedback stimulation, thyroid cells proliferate in excess of their demise. Here, to examine the relative proteotoxicity of the Tg-G2298R protein, we have used CRISPR–CRISPR-associated protein 9 technology to generate homozygous TGrdw/rdw knock-in mice in a strain background identical to that of TGcog/cog mice. TGrdw/rdw mice exhibit similar phenotypes of defective Tg protein folding, thyroid histological abnormalities, hypothyroidism, and growth retardation. TGrdw/rdw mice do not show evidence of greater ER stress response or stress-mediated cell death than TGcog/cog mice, and both mouse models exhibit sustained thyrocyte proliferation, with comparable goiter growth. In contrast, in WIC-TGrdw/rdw rats, as a function of aging, the thyrocyte proliferation rate declines precipitously. We conclude that the mutant Tg-G2298R protein is not intrinsically more proteotoxic than Tg-L2263P; rather, aging-dependent difference in maintenance of cell proliferation is the limiting factor, which accounts for the absence of goiter in adult WIC-TGrdw/rdw rats.
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Affiliation(s)
- Xiaohan Zhang
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical Center, Ann Arbor, Michigan, USA
| | - Bhoomanyu Malik
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical Center, Ann Arbor, Michigan, USA
| | - Crystal Young
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical Center, Ann Arbor, Michigan, USA
| | - Hao Zhang
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical Center, Ann Arbor, Michigan, USA
| | - Dennis Larkin
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical Center, Ann Arbor, Michigan, USA
| | - Xiao-Hui Liao
- Departments of Medicine, Pediatrics, and Committee on Genetics, The University of Chicago, Chicago Illinois, USA
| | - Samuel Refetoff
- Departments of Medicine, Pediatrics, and Committee on Genetics, The University of Chicago, Chicago Illinois, USA
| | - Ming Liu
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Peter Arvan
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical Center, Ann Arbor, Michigan, USA.
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5
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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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6
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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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7
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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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8
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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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9
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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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10
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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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11
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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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12
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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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13
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Zhang X, Shao S, Zhao L, Yang R, Zhao M, Fang L, Li M, Chen W, Song Y, Xu C, Zhou X, Zhao J, Gao L. ER stress contributes to high-fat diet-induced decrease of thyroglobulin and hypothyroidism. Am J Physiol Endocrinol Metab 2019; 316:E510-E518. [PMID: 30620634 DOI: 10.1152/ajpendo.00194.2018] [Citation(s) in RCA: 10] [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] [Indexed: 01/30/2023]
Abstract
Recent studies revealed the emerging role of excess uptake of lipids in the development of hypothyroidism. However, the underlying mechanism is largely unknown. We investigated the effect of high-fat diet (HFD) on thyroid function and the role of endoplasmic reticulum (ER) in HFD-induced hypothyroidism. Male Sprague-Dawley rats were fed with HFD or control diet for 18 wk. HFD rats showed an impaired thyroid function, with decreased thyroglobulin (Tg) level. We found the ER stress was triggered in HFD rat thyroid glands and palmitate-treated thyrocytes. Luminal swelling of ER in thyroid epithelial cells of HFD rats was also observed. The rate of Tg degradation increased in palmitate-treated thyrocytes. In addition, applying 4-phenyl butyric acid to alleviate ER stress in HFD rats improved the decrease of Tg and thyroid function. Withdrawal of the HFD improved thyroid function . In conclusion, we demonstrate that ER stress mediates the HFD-induced hypothyroidism, probably by impairing the production of Tg, and attenuation of ER stress improves thyroid function. Our study provides the understanding of how HFD induces hypothyroidism.
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Affiliation(s)
- Xiaohan Zhang
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong University , Shandong , China
- Shandong Provincial Key Laboratory of Endocrinology and Lipid Metabolism, Ji-nan, Shandong , China
- Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Ji-nan, Shandong , China
| | - Shanshan Shao
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong University , Shandong , China
- Shandong Provincial Key Laboratory of Endocrinology and Lipid Metabolism, Ji-nan, Shandong , China
- Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Ji-nan, Shandong , China
| | - Lifang Zhao
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong University , Shandong , China
- Shandong Provincial Key Laboratory of Endocrinology and Lipid Metabolism, Ji-nan, Shandong , China
- Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Ji-nan, Shandong , China
| | - Rui Yang
- Experimental Animal Center, Shandong Provincial Hospital Affiliated to Shandong University, Ji-nan, Shandong , China
| | - Meng Zhao
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong University , Shandong , China
- Shandong Provincial Key Laboratory of Endocrinology and Lipid Metabolism, Ji-nan, Shandong , China
- Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Ji-nan, Shandong , China
| | - Li Fang
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong University , Shandong , China
- Shandong Provincial Key Laboratory of Endocrinology and Lipid Metabolism, Ji-nan, Shandong , China
- Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Ji-nan, Shandong , China
| | - Mengzhu Li
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong University , Shandong , China
- Shandong Provincial Key Laboratory of Endocrinology and Lipid Metabolism, Ji-nan, Shandong , China
- Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Ji-nan, Shandong , China
| | - Wenbin Chen
- Scientific Center, Shandong Provincial Hospital Affiliated to Shandong University, Ji-nan, Shandong , China
| | - Yongfeng Song
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong University , Shandong , China
- Shandong Provincial Key Laboratory of Endocrinology and Lipid Metabolism, Ji-nan, Shandong , China
- Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Ji-nan, Shandong , China
| | - Chao Xu
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong University , Shandong , China
- Shandong Provincial Key Laboratory of Endocrinology and Lipid Metabolism, Ji-nan, Shandong , China
- Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Ji-nan, Shandong , China
| | - Xiaoming Zhou
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong University , Shandong , China
- Shandong Provincial Key Laboratory of Endocrinology and Lipid Metabolism, Ji-nan, Shandong , China
- Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Ji-nan, Shandong , China
| | - Jiajun Zhao
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong University , Shandong , China
- Shandong Provincial Key Laboratory of Endocrinology and Lipid Metabolism, Ji-nan, Shandong , China
- Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Ji-nan, Shandong , China
| | - Ling Gao
- Shandong Provincial Key Laboratory of Endocrinology and Lipid Metabolism, Ji-nan, Shandong , China
- Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Ji-nan, Shandong , China
- Scientific Center, Shandong Provincial Hospital Affiliated to Shandong University, Ji-nan, Shandong , China
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14
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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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15
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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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16
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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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17
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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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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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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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20
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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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21
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Gidalevitz T, Stevens F, Argon Y. Orchestration of secretory protein folding by ER chaperones. BIOCHIMICA ET BIOPHYSICA ACTA 2013; 1833:2410-24. [PMID: 23507200 PMCID: PMC3729627 DOI: 10.1016/j.bbamcr.2013.03.007] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Revised: 02/27/2013] [Accepted: 03/01/2013] [Indexed: 02/06/2023]
Abstract
The endoplasmic reticulum is a major compartment of protein biogenesis in the cell, dedicated to production of secretory, membrane and organelle proteins. The secretome has distinct structural and post-translational characteristics, since folding in the ER occurs in an environment that is distinct in terms of its ionic composition, dynamics and requirements for quality control. The folding machinery in the ER therefore includes chaperones and folding enzymes that introduce, monitor and react to disulfide bonds, glycans, and fluctuations of luminal calcium. We describe the major chaperone networks in the lumen and discuss how they have distinct modes of operation that enable cells to accomplish highly efficient production of the secretome. This article is part of a Special Issue entitled: Functional and structural diversity of endoplasmic reticulum.
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Affiliation(s)
- Tali Gidalevitz
- Department of Biology, Drexel University, Drexel University, 418 Papadakis Integrated Science Bldg, 3245 Chestnut Street, Philadelphia, PA 19104
| | | | - Yair Argon
- Division of Cell Pathology, Department of Pathology and Lab Medicine, The Children's Hospital of Philadelphia and the University of Pennsylvania, 3615 Civic Center Blvd., Philadelphia, PA 19104, USA, , Phone: 267-426-5131, Fax: 267-426-5165)
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22
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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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