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Matoušková Z, Orsághová K, Srb P, Pytelková J, Kukačka Z, Buša M, Hajdušek O, Šíma R, Fábry M, Novák P, Horn M, Kopáček P, Mareš M. An Unusual Two-Domain Thyropin from Tick Saliva: NMR Solution Structure and Highly Selective Inhibition of Cysteine Cathepsins Modulated by Glycosaminoglycans. Int J Mol Sci 2024; 25:2240. [PMID: 38396918 PMCID: PMC10889554 DOI: 10.3390/ijms25042240] [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: 12/12/2023] [Revised: 02/02/2024] [Accepted: 02/10/2024] [Indexed: 02/25/2024] Open
Abstract
The structure and biochemical properties of protease inhibitors from the thyropin family are poorly understood in parasites and pathogens. Here, we introduce a novel family member, Ir-thyropin (IrThy), which is secreted in the saliva of Ixodes ricinus ticks, vectors of Lyme borreliosis and tick-borne encephalitis. The IrThy molecule consists of two consecutive thyroglobulin type-1 (Tg1) domains with an unusual disulfide pattern. Recombinant IrThy was found to inhibit human host-derived cathepsin proteases with a high specificity for cathepsins V, K, and L among a wide range of screened cathepsins exhibiting diverse endo- and exopeptidase activities. Both Tg1 domains displayed inhibitory activities, but with distinct specificity profiles. We determined the spatial structure of one of the Tg1 domains by solution NMR spectroscopy and described its reactive center to elucidate the unique inhibitory specificity. Furthermore, we found that the inhibitory potency of IrThy was modulated in a complex manner by various glycosaminoglycans from host tissues. IrThy was additionally regulated by pH and proteolytic degradation. This study provides a comprehensive structure-function characterization of IrThy-the first investigated thyropin of parasite origin-and suggests its potential role in host-parasite interactions at the tick bite site.
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Affiliation(s)
- Zuzana Matoušková
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 16610 Praha, Czech Republic; (Z.M.); (K.O.); (M.B.); (M.F.); (M.H.)
- Department of Biochemistry, Faculty of Science, Charles University, Hlavova 8, 12800 Praha, Czech Republic
| | - Katarína Orsághová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 16610 Praha, Czech Republic; (Z.M.); (K.O.); (M.B.); (M.F.); (M.H.)
- First Faculty of Medicine, Charles University, Katerinska 32, 12108 Praha, Czech Republic
| | - Pavel Srb
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 16610 Praha, Czech Republic; (Z.M.); (K.O.); (M.B.); (M.F.); (M.H.)
| | - Jana Pytelková
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 16610 Praha, Czech Republic; (Z.M.); (K.O.); (M.B.); (M.F.); (M.H.)
| | - Zdeněk Kukačka
- Institute of Microbiology, Czech Academy of Sciences, Prumyslova 595, 25250 Vestec, Czech Republic
| | - Michal Buša
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 16610 Praha, Czech Republic; (Z.M.); (K.O.); (M.B.); (M.F.); (M.H.)
| | - Ondřej Hajdušek
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Branisovska 31, 37005 Ceske Budejovice, Czech Republic
| | - Radek Šíma
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Branisovska 31, 37005 Ceske Budejovice, Czech Republic
- Biopticka Laborator, Mikulasske Namesti 4, 32600 Plzen, Czech Republic
| | - Milan Fábry
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 16610 Praha, Czech Republic; (Z.M.); (K.O.); (M.B.); (M.F.); (M.H.)
| | - Petr Novák
- Institute of Microbiology, Czech Academy of Sciences, Prumyslova 595, 25250 Vestec, Czech Republic
| | - Martin Horn
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 16610 Praha, Czech Republic; (Z.M.); (K.O.); (M.B.); (M.F.); (M.H.)
| | - Petr Kopáček
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Branisovska 31, 37005 Ceske Budejovice, Czech Republic
| | - Michael Mareš
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo n. 2, 16610 Praha, Czech Republic; (Z.M.); (K.O.); (M.B.); (M.F.); (M.H.)
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Perišić Nanut M, Pečar Fonović U, Jakoš T, Kos J. The Role of Cysteine Peptidases in Hematopoietic Stem Cell Differentiation and Modulation of Immune System Function. Front Immunol 2021; 12:680279. [PMID: 34335582 PMCID: PMC8322073 DOI: 10.3389/fimmu.2021.680279] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Accepted: 07/01/2021] [Indexed: 01/21/2023] Open
Abstract
Cysteine cathepsins are primarily involved in the degradation and recycling of proteins in endo-lysosomal compartments but are also gaining recognition as pivotal proteolytic contributors to various immune functions. Through their extracellular proteolytic activities within the hematopoietic stem cell niche, they are involved in progenitor cell mobilization and differentiation. Cysteine cathepsins, such as cathepsins L and S contribute to antigen-induced adaptive immunity through major histocompatibility complex class II antigen presentation whereas cathepsin X regulates T-cell migration. By regulating toll-like receptor signaling and cytokine secretion cysteine cathepsins activate innate immune cells and affect their functional differentiation. Cathepsins C and H are expressed in cytotoxic T lymphocytes and natural killer cells and are involved in processing of pro-granzymes into proteolytically active forms. Cytoplasmic activities of cathepsins B and L contribute to the maintenance of homeostasis of the adaptive immune response by regulating cell death of T and B lymphocytes. The expression pattern, localization, and activity of cysteine cathepsins is tightly connected to their function in immune cells. Furthermore, cysteine cathepsins together with their endogenous inhibitors, serve as mediators in the interplay between cancer and immune cells that results in immune cell anergy. The aim of the present article is to review the mechanisms of dysregulation of cysteine cathepsins and their inhibitors in relation to immune dysfunction to address new possibilities for regulation of their function.
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Affiliation(s)
| | | | - Tanja Jakoš
- Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia
| | - Janko Kos
- Department of Biotechnology, Jožef Stefan Institute, Ljubljana, Slovenia.,Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia
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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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Sage J, Leblanc-Noblesse E, Nizard C, Sasaki T, Schnebert S, Perrier E, Kurfurst R, Brömme D, Lalmanach G, Lecaille F. Cleavage of nidogen-1 by cathepsin S impairs its binding to basement membrane partners. PLoS One 2012; 7:e43494. [PMID: 22952693 PMCID: PMC3429489 DOI: 10.1371/journal.pone.0043494] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Accepted: 07/23/2012] [Indexed: 11/18/2022] Open
Abstract
Cathepsin S (catS), which is expressed in normal human keratinocytes and localized close to the dermal-epidermal junction (DEJ) degrades some of major basement membrane (BM) constituents. Among them, catS readily hydrolyzed in a time and dose dependent manner human nidogen-1 (nid-1) and nidogen-2, which are key proteins in the BM structure. CatS preferentially cleaved nid-1 at both acid and neutral pH. Hydrolysis of nid-1 was hampered in murine ctss−/− spleen lysates pretreated with inhibitors of other classes of proteases. Nid-1 was cleaved within its G2 and G3 globular domains that are both involved in interactions with other BM components. Binding assays with soluble and immobilized ligands indicated that catS altered the formation of complexes between nid-1 and other BM components. Assuming that the cleavage of nid-1 impairs its ability to crosslink with BM partners and perturbs the viscoelastic properties of BM matrix, these data indicate that catS may participate in BM proteolysis, in addition to already identified proteases.
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Affiliation(s)
- Juliette Sage
- INSERM, UMR 1100, Pathologies Respiratoires: protéolyse et aérosolthérapie, Centre d’Etude des Pathologies Respiratoires, Tours, France
- Université François Rabelais, UMR 1100, Tours, France
- Louis Vuitton Moët Hennessy (LVMH-Recherche), Saint Jean de Braye, France
| | | | - Carine Nizard
- Louis Vuitton Moët Hennessy (LVMH-Recherche), Saint Jean de Braye, France
- Laboratoire de Pharmacologie Cellulaire de l’Ecole Pratique des Hautes Etudes, Centre de Recherche des Cordeliers, Paris, France
| | - Takako Sasaki
- Department of Experimental Medicine I, Nikolaus-Fiebiger Center for Molecular Medicine, University of Erlangen-Nuremberg, Erlangen, Germany
| | | | - Eric Perrier
- Louis Vuitton Moët Hennessy (LVMH-Recherche), Saint Jean de Braye, France
| | - Robin Kurfurst
- Louis Vuitton Moët Hennessy (LVMH-Recherche), Saint Jean de Braye, France
| | - Dieter Brömme
- University of British Columbia, Department of Oral Biological and Medical Sciences, Vancouver, British Columbia, Canada
| | - Gilles Lalmanach
- INSERM, UMR 1100, Pathologies Respiratoires: protéolyse et aérosolthérapie, Centre d’Etude des Pathologies Respiratoires, Tours, France
- Université François Rabelais, UMR 1100, Tours, France
| | - Fabien Lecaille
- INSERM, UMR 1100, Pathologies Respiratoires: protéolyse et aérosolthérapie, Centre d’Etude des Pathologies Respiratoires, Tours, France
- Université François Rabelais, UMR 1100, Tours, France
- * E-mail:
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Suban D, Zajc T, Renko M, Turk B, Turk V, Dolenc I. Cathepsin C and plasma glutamate carboxypeptidase secreted from Fischer rat thyroid cells liberate thyroxin from the N-terminus of thyroglobulin. Biochimie 2011; 94:719-26. [PMID: 22127294 DOI: 10.1016/j.biochi.2011.10.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2011] [Accepted: 10/30/2011] [Indexed: 11/28/2022]
Abstract
The release of a thyroid hormone from thyroglobulin is controlled by a complex regulatory system. We focused on the extracellular action of two lysosomal enzymes, cathepsin C (catC, dipeptidyl peptidase I) and PGCP (lysosomal dipeptidase), on thyroglobulin, and their ability to liberate the hormone thyroxin. Cathepsin C, an exopeptidase, removes dipeptides from the N-terminus of substrates, and PGCP hydrolyses dipeptides to amino acids. In vitro experiments proved that cathepsin C removes up to 12 amino acids from the N-terminus of porcine thyroglobulin, including a dipeptide with thyroxin on position 5. The newly formed N-terminus, Arg-Pro-, was not hydrolysed further by cathepsin C. Cell culture experiments with FRTL-5 cell line showed localization of cathepsin C and PGCP and their secretion into the medium. Secretion of the active cathepsin C from FRTL-5 cells is stimulated by TSH, insulin, and/or somatostatin. The released enzymes liberate thyroxin from porcine thyroglobulin added to media. The hormone liberation can be reduced by synthetic inhibitors of cysteine proteinases and metalloproteinases. Additionally, we show that TSH, insulin, and/or somatostatin induce up-regulation of N-acetylglucosaminyltransferase 1, the enzyme responsible for the initiation of biosynthesis of hybrid and complex N-glycosylation of proteins.
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Affiliation(s)
- Dejan Suban
- Department of Biochemistry and Molecular and Structural Biology, Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia
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Rainger J, van Beusekom E, Ramsay JK, McKie L, Al-Gazali L, Pallotta R, Saponari A, Branney P, Fisher M, Morrison H, Bicknell L, Gautier P, Perry P, Sokhi K, Sexton D, Bardakjian TM, Schneider AS, Elcioglu N, Ozkinay F, Koenig R, Mégarbané A, Semerci CN, Khan A, Zafar S, Hennekam R, Sousa SB, Ramos L, Garavelli L, Furga AS, Wischmeijer A, Jackson IJ, Gillessen-Kaesbach G, Brunner HG, Wieczorek D, van Bokhoven H, FitzPatrick DR. Loss of the BMP antagonist, SMOC-1, causes Ophthalmo-acromelic (Waardenburg Anophthalmia) syndrome in humans and mice. PLoS Genet 2011; 7:e1002114. [PMID: 21750680 PMCID: PMC3131273 DOI: 10.1371/journal.pgen.1002114] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2010] [Accepted: 04/15/2011] [Indexed: 01/23/2023] Open
Abstract
Ophthalmo-acromelic syndrome (OAS), also known as Waardenburg Anophthalmia syndrome, is defined by the combination of eye malformations, most commonly bilateral anophthalmia, with post-axial oligosyndactyly. Homozygosity mapping and subsequent targeted mutation analysis of a locus on 14q24.2 identified homozygous mutations in SMOC1 (SPARC-related modular calcium binding 1) in eight unrelated families. Four of these mutations are nonsense, two frame-shift, and two missense. The missense mutations are both in the second Thyroglobulin Type-1 (Tg1) domain of the protein. The orthologous gene in the mouse, Smoc1, shows site- and stage-specific expression during eye, limb, craniofacial, and somite development. We also report a targeted pre-conditional gene-trap mutation of Smoc1 (Smoc1tm1a) that reduces mRNA to ∼10% of wild-type levels. This gene-trap results in highly penetrant hindlimb post-axial oligosyndactyly in homozygous mutant animals (Smoc1tm1a/tm1a). Eye malformations, most commonly coloboma, and cleft palate occur in a significant proportion of Smoc1tm1a/tm1a embryos and pups. Thus partial loss of Smoc-1 results in a convincing phenocopy of the human disease. SMOC-1 is one of the two mammalian paralogs of Drosophila Pentagone, an inhibitor of decapentaplegic. The orthologous gene in Xenopus laevis, Smoc-1, also functions as a Bone Morphogenic Protein (BMP) antagonist in early embryogenesis. Loss of BMP antagonism during mammalian development provides a plausible explanation for both the limb and eye phenotype in humans and mice. Ophthalmo-acromelic syndrome (OAS) is a rare congenital genetic disorder involving complete absence of the eyes and limb malformations, with missing or fused bones in the feet and hands. In this paper we report the identification of genetic changes to both copies of the SMOC1 gene as the cause of most cases of OAS. We have identified eight different mutations in this gene in unrelated individuals, and six of these mutations are predicted to completely abolish SMOC-1 function. We have also genetically disrupted the mouse Smoc1 gene to produce only 10% of normal levels. These animals, called Smoc1tm1a/tm1a mice, have similar hindlimb malformations to those seen in the limbs of human OAS patients, resulting in missing toes in some mice and fusion of toes in others. Smoc1tm1a/tm1a embryos and pups also have eye malformations but these are milder than those seen in human cases, perhaps because, unlike the human cases, the mice still have some residual function of the gene. We suggest that the normal function of SMOC-1 may be to regulate an important class of growth factors, called Bone Morphogenetic Proteins (BMPs), which are essential for normal embryonic development.
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Affiliation(s)
- Joe Rainger
- Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital, Edinburgh, United Kingdom
| | - Ellen van Beusekom
- Department of Human Genetics, Institute for Genetic and Metabolic Disorders and Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Jacqueline K. Ramsay
- Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital, Edinburgh, United Kingdom
| | - Lisa McKie
- Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital, Edinburgh, United Kingdom
| | - Lihadh Al-Gazali
- Departments of Paediatrics, Faculty of Medicine and Health Sciences, United Arab Emirates University, Al-Ain, United Arab Emirates
| | - Rosanna Pallotta
- Regional Service for Diagnosis, Prevention, and Care of Birth Defects, Department of Medicine and Aging Sciences, Section of Preventive and Social Pediatrics, G. D'Annunzio University, Chieti, Italy
| | - Anita Saponari
- Regional Service for Diagnosis, Prevention, and Care of Birth Defects, Department of Medicine and Aging Sciences, Section of Preventive and Social Pediatrics, G. D'Annunzio University, Chieti, Italy
| | - Peter Branney
- Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital, Edinburgh, United Kingdom
| | - Malcolm Fisher
- Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital, Edinburgh, United Kingdom
| | - Harris Morrison
- Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital, Edinburgh, United Kingdom
| | - Louise Bicknell
- Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital, Edinburgh, United Kingdom
| | - Philippe Gautier
- Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital, Edinburgh, United Kingdom
| | - Paul Perry
- Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital, Edinburgh, United Kingdom
| | - Kishan Sokhi
- Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital, Edinburgh, United Kingdom
- Department of Orthopaedics and Trauma, University of Edinburgh, Royal Infirmary of Edinburgh, Little France, Edinburgh, United Kingdom
| | - David Sexton
- Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital, Edinburgh, United Kingdom
| | - Tanya M. Bardakjian
- Division of Genetics, Department of Pediatrics, Albert Einstein Medical Center, Philadelphia, Pennsylvania, United States of America
| | - Adele S. Schneider
- Division of Genetics, Department of Pediatrics, Albert Einstein Medical Center, Philadelphia, Pennsylvania, United States of America
| | - Nursel Elcioglu
- Department of Pediatric Genetics, Marmara University Hospital, Istanbul, Turkey
| | - Ferda Ozkinay
- Ege University, Medical Faculty, Department of Pediatrics, Izmir, Turkey
| | - Rainer Koenig
- Institut für Humangenetik der Johann Wolfgang Goethe Universität, Frankfurt, Germany
| | - Andre Mégarbané
- Unité de Génétique Médicale, Faculté de Médecine, Université Saint Joseph, Beirut, Lebanon
| | - C. Nur Semerci
- Department of Medical Genetics, School of Medicine, Pamukkale University, Denizli, Turkey
| | - Ayesha Khan
- Al-Shifa Trust Eye Hospital, Rawalpindi, Pakistan
| | - Saemah Zafar
- Al-Shifa Trust Eye Hospital, Rawalpindi, Pakistan
| | - Raoul Hennekam
- Department of Pediatrics and Department of Translational Genetics, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Sérgio B. Sousa
- Serviço Genética Médica, Hospital Pediátrico de Coimbra, Portugal
| | - Lina Ramos
- Serviço Genética Médica, Hospital Pediátrico de Coimbra, Portugal
| | - Livia Garavelli
- Department of Clinical Genetics, S. Maria Nuova Hospital, Reggio Emilia, Italy
| | | | - Anita Wischmeijer
- Department of Clinical Genetics, S. Maria Nuova Hospital, Reggio Emilia, Italy
| | - Ian J. Jackson
- Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital, Edinburgh, United Kingdom
| | | | - Han G. Brunner
- Department of Human Genetics, Institute for Genetic and Metabolic Disorders and Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Dagmar Wieczorek
- Institut für Humangenetik, Universitätsklinikum Essen, Essen, Germany
| | - Hans van Bokhoven
- Department of Human Genetics, Institute for Genetic and Metabolic Disorders and Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
- * E-mail: (DRF); (HvB)
| | - David R. FitzPatrick
- Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital, Edinburgh, United Kingdom
- * E-mail: (DRF); (HvB)
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Abstract
Thyroglobulin type-1 repeats are primarily found in thyroglobulin and several other functionally unrelated proteins. Because a few of them exhibit inhibitory activity against cysteine proteases they were named thyropins (thyroglobulin type-1 domain protease inhibitors). In contrast to cystatins, the best-characterized group of papain-like protease inhibitors, they exhibit greater selectivity in their interactions with target proteases. Interestingly, a few members inhibit aspartic protease cathepsin D and metalloproteases. In contrast to the inhibitory fragment of the major histocompatibility complex class II-associated p41 form of invariant chain, whose structural integrity appears mandatory for its inhibitory properties, short polypeptides derived from insulin-like growth factor-binding proteins exhibit the same activity as the structure of the whole fragment. Taken together, the results indicate that the thyroglobulin type-1 repeat is a structural motif occasionally employed as an inhibitor of proteases.
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Affiliation(s)
- Marko Mihelic
- Department of Biochemistry, Molecular and Structural Biology, Jozef Stefan Institute, Jamova 39, SI-1000, Ljubljana, Slovenia
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Novinec M, Kordis D, Turk V, Lenarcic B. Diversity and Evolution of the Thyroglobulin Type-1 Domain Superfamily. Mol Biol Evol 2005; 23:744-55. [PMID: 16368776 DOI: 10.1093/molbev/msj082] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Multidomain proteins are gaining increasing consideration for their puzzling, flexible utilization in nature. The presence of the characteristic thyroglobulin type-1 (Tg1) domain as a protein module in a variety of multicellular organisms suggests pivotal roles for this building block. To gain insight into the evolution of Tg1 domains, we performed searches of protein, expressed sequence tag, and genome databases. Tg1 domains were found to be Metazoa specific, and we retrieved a total of 170 Tg1 domain-containing protein sequences. Their architectures revealed a wide taxonomic distribution of proteins containing Tg1 domains followed or preceded by secreted protein, acidic, rich in cysteines (SPARC)-type extracellular calcium-binding domains. Other proteins contained lineage-specific domain combinations of peptidase inhibitory modules or domains with different biological functions. Phylogenetic analysis showed that Tg1 domains are highly conserved within protein structures, whereas insertion into novel proteins is followed by rapid diversification. Seven different basic types of protein architecture containing the Tg1 domain were identified in vertebrates. We examined the evolution of these protein groups by combining Tg1 domain phylogeny with additional analyses based on other characteristic domains. Testicans and secreted modular calcium binding protein (SMOCs) evolved from invertebrate homologs by introduction of vertebrate-specific domains, nidogen evolved by insertion of a Tg1 domain into a preexisting architecture, and the remaining four have unique architectures. Thyroglobulin, Trops, and the major histocompatibility complex class II-associated invariant chain are vertebrate specific, while an insulin-like growth factor-binding protein and nidogen were also identified in urochordates. Among vertebrates, we observed differences in protein repertoires, which result from gene duplication and domain duplication. Members of five groups have been characterized at the molecular level. All exhibit subtle differences in their specificities and function either as peptidase inhibitors (thyropins), substrates, or both. As far as the sequence is concerned, only a few conserved residues were identified. In combination with structural data, our analysis shows that the Tg1 domain fold is highly adaptive and comprises a relatively well-conserved core surrounded by highly variable loops that account for its multipurpose function in the animal kingdom.
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Affiliation(s)
- Marko Novinec
- Department of Biochemistry and Molecular Biology, JoZef Stefan Institute, Jamova 39, Ljubljana, Slovenia
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Park YN, Arvan P. The Acetylcholinesterase Homology Region Is Essential for Normal Conformational Maturation and Secretion of Thyroglobulin. J Biol Chem 2004; 279:17085-9. [PMID: 14764582 DOI: 10.1074/jbc.m314042200] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Secretion of thyroglobulin (Tg, a large homodimeric glycoprotein) is essential to deliver Tg to its site of iodination for thyroxine biosynthesis. An L2263P missense mutation in Tg has been proposed as the molecular defect causing congenital goitrous hypothyroidism in cog/cog mice due to perturbed Tg homodimerization, resulting in its retention within the endoplasmic reticulum. The mutation falls within a carboxyl-terminal region of Tg with high structural similarity to the entirety of acetylcholinesterase (AChE), a secretory protein that also forms homodimers. We provide new evidence that authentic AChE and the cholinesterase-like domain of Tg share a common tertiary structure. Moreover, we find that a Tg truncation, deleted of the cholinesterase-like region (but not a comparably sized deletion of internal Tg regions), blocks Tg export. Appending to this truncation a cDNA encoding authentic AChE results in translation of a chimeric protein in which AChE is present in a native, enzymatically active (albeit latent) conformation, and this fully rescues Tg secretion. Introduction of the cog mutation inhibits AChE enzyme activity, and established denaturing mutations of AChE block secretion of the Tg. Additional studies show that the native structure of the AChE region functions as a "dimerization domain," facilitating intracellular transport of Tg to the site of thyroid hormonogenesis.
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Affiliation(s)
- Young-Nam Park
- Division of Metabolism, Endocrinology, and Diabetes and the Program of Cellular and Molecular Biology, University of Michigan Medical Center, Ann Arbor, Michigan 48109, USA
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