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Ruf M, Cunningham S, Wandersee A, Brox R, Achenbach S, Strobel J, Hackstein H, Schneider S. SERPINC1 c.1247dupC: a novel SERPINC1 gene mutation associated with familial thrombosis results in a secretion defect and quantitative antithrombin deficiency. Thromb J 2024; 22:19. [PMID: 38347553 PMCID: PMC10860291 DOI: 10.1186/s12959-024-00589-5] [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: 08/31/2023] [Accepted: 02/01/2024] [Indexed: 02/16/2024] Open
Abstract
BACKGROUND Antithrombin (AT) is an important anticoagulant in hemostasis. We describe here the characterization of a novel AT mutation associated with clinically relevant thrombosis. A pair of sisters with confirmed type I AT protein deficiency was genetically analyzed on suspicion of an inherited SERPINC1 mutation. A frameshift mutation, c.1247dupC, was identified and the effect of this mutation was examined on the cellular and molecular level. METHODS Plasmids for the expression of wild-type (WT) and mutated SERPINC1 coding sequence (CDS) fused to green fluorescent protein (GFP) or hemagglutinin (HA) tag were transfected into HEK293T cells. Subcellular localization and secretion of the respective fusion proteins were analyzed by confocal laser scanning microscopy and Western blot. RESULTS The c.1247dupC mutation results in a frameshift in the CDS of the SERPINC1 gene and a subsequently altered amino acid sequence (p.Ser417LysfsTer48). This alteration affects the C-terminus of the AT antigen and results in impaired secretion as confirmed by GFP- and HA-tagged mutant AT analyzed in HEK293T cells. CONCLUSION The p.Ser417LysfsTer48 mutation leads to impaired secretion, thus resulting in a quantitative AT deficiency. This is in line with the type I AT deficiency observed in the patients.
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Affiliation(s)
- Maximilian Ruf
- Department of Transfusion Medicine and Hemostaseology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), University Hospital Erlangen, Krankenhausstr. 12, 91054, Erlangen, Germany
| | - Sarah Cunningham
- Department of Transfusion Medicine and Hemostaseology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), University Hospital Erlangen, Krankenhausstr. 12, 91054, Erlangen, Germany
| | - Alexandra Wandersee
- Department of Transfusion Medicine and Hemostaseology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), University Hospital Erlangen, Krankenhausstr. 12, 91054, Erlangen, Germany
| | - Regine Brox
- Department of Transfusion Medicine and Hemostaseology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), University Hospital Erlangen, Krankenhausstr. 12, 91054, Erlangen, Germany
| | - Susanne Achenbach
- Department of Transfusion Medicine and Hemostaseology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), University Hospital Erlangen, Krankenhausstr. 12, 91054, Erlangen, Germany
| | - Julian Strobel
- Department of Transfusion Medicine and Hemostaseology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), University Hospital Erlangen, Krankenhausstr. 12, 91054, Erlangen, Germany
| | - Holger Hackstein
- Department of Transfusion Medicine and Hemostaseology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), University Hospital Erlangen, Krankenhausstr. 12, 91054, Erlangen, Germany
| | - Sabine Schneider
- Department of Transfusion Medicine and Hemostaseology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), University Hospital Erlangen, Krankenhausstr. 12, 91054, Erlangen, Germany.
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D'Acunto E, Gianfrancesco L, Serangeli I, D'Orsi M, Sabato V, Guadagno NA, Bhosale G, Caristi S, Failla AV, De Jaco A, Cacci E, Duchen MR, Lupo G, Galliciotti G, Miranda E. Polymerogenic neuroserpin causes mitochondrial alterations and activates NFκB but not the UPR in a neuronal model of neurodegeneration FENIB. Cell Mol Life Sci 2022; 79:437. [PMID: 35864382 PMCID: PMC9304071 DOI: 10.1007/s00018-022-04463-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 06/10/2022] [Accepted: 07/02/2022] [Indexed: 12/02/2022]
Abstract
The neurodegenerative condition FENIB (familiar encephalopathy with neuroserpin inclusion bodies) is caused by heterozygous expression of polymerogenic mutant neuroserpin (NS), with polymer deposition within the endoplasmic reticulum (ER) of neurons. We generated transgenic neural progenitor cells (NPCs) from mouse fetal cerebral cortex stably expressing either the control protein GFP or human wild type, polymerogenic G392E or truncated (delta) NS. This cellular model makes it possible to study the toxicity of polymerogenic NS in the appropriated cell type by in vitro differentiation to neurons. Our previous work showed that expression of G392E NS in differentiated NPCs induced an adaptive response through the upregulation of several genes involved in the defence against oxidative stress, and that pharmacological reduction of the antioxidant defences by drug treatments rendered G392E NS neurons more susceptible to apoptosis than control neurons. In this study, we assessed mitochondrial distribution and found a higher percentage of perinuclear localisation in G392E NS neurons, particularly in those containing polymers, a phenotype that was enhanced by glutathione chelation and rescued by antioxidant molecules. Mitochondrial membrane potential and contact sites between mitochondria and the ER were reduced in neurons expressing the G392E mutation. These alterations were associated with a pattern of ER stress that involved the ER overload response but not the unfolded protein response. Our results suggest that intracellular accumulation of NS polymers affects the interaction between the ER and mitochondria, causing mitochondrial alterations that contribute to the neuronal degeneration seen in FENIB patients.
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Affiliation(s)
- E D'Acunto
- Department of Biology and Biotechnologies 'Charles Darwin', Sapienza University of Rome, P.le Aldo Moro 5, 00185, Rome, Italy
| | - L Gianfrancesco
- Department of Biology and Biotechnologies 'Charles Darwin', Sapienza University of Rome, P.le Aldo Moro 5, 00185, Rome, Italy
| | - I Serangeli
- Department of Biology and Biotechnologies 'Charles Darwin', Sapienza University of Rome, P.le Aldo Moro 5, 00185, Rome, Italy
| | - M D'Orsi
- Department of Biology and Biotechnologies 'Charles Darwin', Sapienza University of Rome, P.le Aldo Moro 5, 00185, Rome, Italy
| | - V Sabato
- Department of Biology and Biotechnologies 'Charles Darwin', Sapienza University of Rome, P.le Aldo Moro 5, 00185, Rome, Italy
| | - N A Guadagno
- Department of Biology and Biotechnologies 'Charles Darwin', Sapienza University of Rome, P.le Aldo Moro 5, 00185, Rome, Italy
| | - G Bhosale
- Department of Cell and Developmental Biology, University College London, London, UK
| | - S Caristi
- Department of Biology and Biotechnologies 'Charles Darwin', Sapienza University of Rome, P.le Aldo Moro 5, 00185, Rome, Italy
| | - A V Failla
- University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - A De Jaco
- Department of Biology and Biotechnologies 'Charles Darwin', Sapienza University of Rome, P.le Aldo Moro 5, 00185, Rome, Italy
| | - E Cacci
- Department of Biology and Biotechnologies 'Charles Darwin', Sapienza University of Rome, P.le Aldo Moro 5, 00185, Rome, Italy
| | - M R Duchen
- Department of Cell and Developmental Biology, University College London, London, UK
| | - G Lupo
- Department of Biology and Biotechnologies 'Charles Darwin', Sapienza University of Rome, P.le Aldo Moro 5, 00185, Rome, Italy
| | - G Galliciotti
- University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - E Miranda
- Department of Biology and Biotechnologies 'Charles Darwin', Sapienza University of Rome, P.le Aldo Moro 5, 00185, Rome, Italy.
- Pasteur Institute-Cenci Bolognetti Foundation, Sapienza University of Rome, Rome, Italy.
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3
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D'Acunto E, Fra A, Visentin C, Manno M, Ricagno S, Galliciotti G, Miranda E. Neuroserpin: structure, function, physiology and pathology. Cell Mol Life Sci 2021; 78:6409-6430. [PMID: 34405255 PMCID: PMC8558161 DOI: 10.1007/s00018-021-03907-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 07/23/2021] [Accepted: 07/27/2021] [Indexed: 12/24/2022]
Abstract
Neuroserpin is a serine protease inhibitor identified in a search for proteins implicated in neuronal axon growth and synapse formation. Since its discovery over 30 years ago, it has been the focus of active research. Many efforts have concentrated in elucidating its neuroprotective role in brain ischemic lesions, the structural bases of neuroserpin conformational change and the effects of neuroserpin polymers that underlie the neurodegenerative disease FENIB (familial encephalopathy with neuroserpin inclusion bodies), but the investigation of the physiological roles of neuroserpin has increased over the last years. In this review, we present an updated and critical revision of the current literature dealing with neuroserpin, covering all aspects of research including the expression and physiological roles of neuroserpin, both inside and outside the nervous system; its inhibitory and non-inhibitory mechanisms of action; the molecular structure of the monomeric and polymeric conformations of neuroserpin, including a detailed description of the polymerisation mechanism; and the involvement of neuroserpin in human disease, with particular emphasis on FENIB. Finally, we briefly discuss the identification by genome-wide screening of novel neuroserpin variants and their possible pathogenicity.
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Affiliation(s)
- Emanuela D'Acunto
- Department of Biology and Biotechnologies 'Charles Darwin', Sapienza University of Rome, Rome, Italy
| | - Annamaria Fra
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Cristina Visentin
- Department of Biosciences, University of Milan, Milan, Italy
- Institute of Molecular and Translational Cardiology, I.R.C.C.S. Policlinico San Donato, Milan, Italy
| | - Mauro Manno
- Institute of Biophysics, National Research Council of Italy, Palermo, Italy
| | - Stefano Ricagno
- Department of Biosciences, University of Milan, Milan, Italy
| | - Giovanna Galliciotti
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Elena Miranda
- Department of Biology and Biotechnologies 'Charles Darwin', Sapienza University of Rome, Rome, Italy.
- Pasteur Institute-Cenci Bolognetti Foundation, Sapienza University of Rome, Rome, Italy.
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Molecular characterization of four novel serpins in Psoroptes ovis var. cuniculi and their implications in the host-parasite interaction. Int J Biol Macromol 2021; 182:1399-1408. [PMID: 34000318 DOI: 10.1016/j.ijbiomac.2021.05.090] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 05/06/2021] [Accepted: 05/12/2021] [Indexed: 11/23/2022]
Abstract
Psoroptes ovis var. cuniculi infestation rapidly causes skin lesion, cutaneous inflammatory and subsequent adaptive immune response in rabbits. To success feeding and survive on the host skin, this mite should product bioactive molecules to confront host tissue repair and immune defense, but these molecules of this mite remains mostly unknown. Serpins have been proved to involve in diverse biological functions including parasite reproduction, survival and modulating host defense. Limited information is currently available on serpins from Psoroptes mites. Herein, we identified four novel serpins (PsoSP3-PsoSP6) in P. ovis var. cuniculi using bioinformatics and molecular biology techniques. Sequence analysis revealed that PsoSP3-PsoSP6 comprised the common features of typical serpins superfamily including serpin domains, signature or the reactive centre loop (RCL) domain. The recombinant PsoSP4-PsoSP6 (rPsoSP4-rPsoSP6) revealed variable potency inhibition on trypsin, chymotrypsin and elastase except for rPsoSP3 in inhibitory activity assays. By quantitative RT-PCR, the expressions of PsoSP3 and PsoSP4 were higher in juvenile mites (larva and nymph) than in adult mites, however, PsoSP5 and PsoSP6 appeared near-exclusive expression in adult female mites. Immunolocalization showed that native PsoSP4 protein was localized in uterus, whilst native PsoSP3, PsoSP5 and PsoSP6 were specifically localized in the ovarian nutritive cell (ONC) in ovary. Our findings indicated that PsoSP3-PsoSP6 might play critical roles in development and reproduction physiologies. rPsoSP4-rPsoSP6 might participate in modulating host inflammation, immune response and tissue repair.
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5
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Ingwersen T, Linnenberg C, D'Acunto E, Temori S, Paolucci I, Wasilewski D, Mohammadi B, Kirchmair J, Glen RC, Miranda E, Glatzel M, Galliciotti G. G392E neuroserpin causing the dementia FENIB is secreted from cells but is not synaptotoxic. Sci Rep 2021; 11:8766. [PMID: 33888787 PMCID: PMC8062559 DOI: 10.1038/s41598-021-88090-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 04/06/2021] [Indexed: 12/21/2022] Open
Abstract
Familial encephalopathy with neuroserpin inclusion bodies (FENIB) is a progressive neurodegenerative disease caused by point mutations in the gene for neuroserpin, a serine protease inhibitor of the nervous system. Different mutations are known that are responsible for mutant neuroserpin polymerization and accumulation as inclusion bodies in many cortical and subcortical neurons, thereby leading to cell death, dementia and epilepsy. Many efforts have been undertaken to elucidate the molecular pathways responsible for neuronal death. Most investigations have concentrated on analysis of intracellular mechanisms such as endoplasmic reticulum (ER) stress, ER-associated protein degradation (ERAD) and oxidative stress. We have generated a HEK-293 cell model of FENIB by overexpressing G392E-mutant neuroserpin and in this study we examine trafficking and toxicity of this polymerogenic variant. We observed that a small fraction of mutant neuroserpin is secreted via the ER-to-Golgi pathway, and that this release can be pharmacologically regulated. Overexpression of the mutant form of neuroserpin did not stimulate cell death in the HEK-293 cell model. Finally, when treating primary hippocampal neurons with G392E neuroserpin polymers, we did not detect cytotoxicity or synaptotoxicity. Altogether, we report here that a polymerogenic mutant form of neuroserpin is secreted from cells but is not toxic in the extracellular milieu.
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Affiliation(s)
- Thies Ingwersen
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Christian Linnenberg
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
| | - Emanuela D'Acunto
- Department of Biology and Biotechnologies 'Charles Darwin', Sapienza University of Rome, Rome, Italy
| | - Shabnam Temori
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
| | - Irene Paolucci
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
| | - David Wasilewski
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
| | - Behnam Mohammadi
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
| | - Johannes Kirchmair
- Centre for Molecular Informatics, Department of Chemistry, University of Cambridge, Cambridge, UK
- Department of Pharmaceutical Chemistry, Faculty of Life Sciences, University of Vienna, Vienna, Austria
| | - Robert C Glen
- Centre for Molecular Informatics, Department of Chemistry, University of Cambridge, Cambridge, UK
- Division of Systems Medicine, Department of Metabolism Digestion and Reproduction, Imperial College London, London, UK
| | - Elena Miranda
- Department of Biology and Biotechnologies 'Charles Darwin', Sapienza University of Rome, Rome, Italy
- Pasteur Institute - Cenci Bolognetti Foundation, Sapienza University of Rome, Rome, Italy
| | - Markus Glatzel
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
| | - Giovanna Galliciotti
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany.
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6
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Ansari S, Ray A, Ali MF, Bano S, Jairajpuri MA. Contrasting conformational dynamics of β-sheet A and helix F with implications in neuroserpin inhibition and aggregation. Int J Biol Macromol 2021; 176:117-125. [PMID: 33516851 DOI: 10.1016/j.ijbiomac.2021.01.171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 01/18/2021] [Accepted: 01/26/2021] [Indexed: 11/25/2022]
Abstract
Neuroserpin (NS) is an inhibitory protein of serpin super family, its shutter region variants have high propensity to aggregate leading to pathological disorders like familial encephalopathy with NS inclusion bodies (FENIB). Helix F and β-sheet A of NS participate in the tissue plasminogen activator (tPA) inhibition but the mechanism is not yet completely understood. A microsecond (μs) molecular dynamics simulation of the helix F and strand 3A variants showed predominant fluctuations in the loop connecting the strands of β-sheet A. Therefore to understand the role of helix F and strand 3A of β-sheet A, cysteine was incorporated at the position N182 in stand 3A (N182C) and position W154 (W154C) in the helix F using site-directed mutagenesis. Purified variants were further labeled with Alexa Fluor488 C5 maleimide dye. Temperature dependent study using non-denaturing PAGE showed the formation of large aggregates of helix F variant W154C but not the strand 3A N182C variant. Interestingly tPA inhibition was found to be decreased in the labeled N182C with decreased tPA-complex formation as compared to labeled W154C NS variant. The fluorescence emission intensity of the labeled helix F variant W154C decreased in the presence of an increasing concentration of tPA, whereas an increase in emission intensity was observed in labeled strand 3A variant N182C, indicating more exposure of strand 3A and shielding of helix F. Taken together the data shows that helix F has a predominant role in the aggregation but a minor role in the inhibition mechanism.
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Affiliation(s)
- Shoyab Ansari
- Protein Conformation and Enzymology Lab, Department of Biosciences, Jamia Millia Islamia (A Central University), New Delhi 110025, India
| | - Arjun Ray
- Department of Computational Biology, Indraprastha Institute of Information Technology, New Delhi 110020, India
| | - Mohammad Farhan Ali
- Protein Conformation and Enzymology Lab, Department of Biosciences, Jamia Millia Islamia (A Central University), New Delhi 110025, India
| | - Shadabi Bano
- Protein Conformation and Enzymology Lab, Department of Biosciences, Jamia Millia Islamia (A Central University), New Delhi 110025, India
| | - Mohamad Aman Jairajpuri
- Protein Conformation and Enzymology Lab, Department of Biosciences, Jamia Millia Islamia (A Central University), New Delhi 110025, India.
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7
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Faull SV, Elliston ELK, Gooptu B, Jagger AM, Aldobiyan I, Redzej A, Badaoui M, Heyer-Chauhan N, Rashid ST, Reynolds GM, Adams DH, Miranda E, Orlova EV, Irving JA, Lomas DA. The structural basis for Z α 1-antitrypsin polymerization in the liver. SCIENCE ADVANCES 2020; 6:6/43/eabc1370. [PMID: 33087346 PMCID: PMC7577719 DOI: 10.1126/sciadv.abc1370] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Accepted: 09/08/2020] [Indexed: 05/22/2023]
Abstract
The serpinopathies are among a diverse set of conformational diseases that involve the aberrant self-association of proteins into ordered aggregates. α1-Antitrypsin deficiency is the archetypal serpinopathy and results from the formation and deposition of mutant forms of α1-antitrypsin as "polymer" chains in liver tissue. No detailed structural analysis has been performed of this material. Moreover, there is little information on the relevance of well-studied artificially induced polymers to these disease-associated molecules. We have isolated polymers from the liver tissue of Z α1-antitrypsin homozygotes (E342K) who have undergone transplantation, labeled them using a Fab fragment, and performed single-particle analysis of negative-stain electron micrographs. The data show structural equivalence between heat-induced and ex vivo polymers and that the intersubunit linkage is best explained by a carboxyl-terminal domain swap between molecules of α1-antitrypsin.
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Affiliation(s)
- Sarah V Faull
- UCL Respiratory, University College London, 5 University Street, London WC1E 6JF, UK
| | - Emma L K Elliston
- UCL Respiratory, University College London, 5 University Street, London WC1E 6JF, UK
- Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BN, UK
| | - Bibek Gooptu
- Leicester Institute of Structural and Chemical Biology, University of Leicester, Henry Wellcome Building, Lancaster Road, Leicester LE1 7HB, UK
- National Institute for Health Research (NIHR) Leicester BRC-Respiratory, Leicester, UK
- Institute of Structural and Molecular Biology, Birkbeck College, Malet Street, University of London, London WC1E 7HX, UK
| | - Alistair M Jagger
- UCL Respiratory, University College London, 5 University Street, London WC1E 6JF, UK
- Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BN, UK
| | - Ibrahim Aldobiyan
- UCL Respiratory, University College London, 5 University Street, London WC1E 6JF, UK
- Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BN, UK
| | - Adam Redzej
- Institute of Structural and Molecular Biology, Birkbeck College, Malet Street, University of London, London WC1E 7HX, UK
| | - Magd Badaoui
- UCL Respiratory, University College London, 5 University Street, London WC1E 6JF, UK
| | - Nina Heyer-Chauhan
- UCL Respiratory, University College London, 5 University Street, London WC1E 6JF, UK
- Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BN, UK
| | - S Tamir Rashid
- Centre for Stem Cells and Regenerative Medicine and Institute for Liver Studies, King's College London, London WC2R 2LS, UK
| | - Gary M Reynolds
- Centre for Liver Research and NIHR Birmingham Liver Biomedical Research Unit, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
| | - David H Adams
- Centre for Liver Research and NIHR Birmingham Liver Biomedical Research Unit, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
| | - Elena Miranda
- Department of Biology and Biotechnologies "Charles Darwin" and Pasteur Institute-Cenci Bolognetti Foundation, Sapienza University of Rome, Rome, Italy
| | - Elena V Orlova
- Institute of Structural and Molecular Biology, Birkbeck College, Malet Street, University of London, London WC1E 7HX, UK
| | - James A Irving
- UCL Respiratory, University College London, 5 University Street, London WC1E 6JF, UK.
- Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BN, UK
| | - David A Lomas
- UCL Respiratory, University College London, 5 University Street, London WC1E 6JF, UK.
- Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BN, UK
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8
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Visentin C, Broggini L, Sala BM, Russo R, Barbiroli A, Santambrogio C, Nonnis S, Dubnovitsky A, Bolognesi M, Miranda E, Achour A, Ricagno S. Glycosylation Tunes Neuroserpin Physiological and Pathological Properties. Int J Mol Sci 2020; 21:E3235. [PMID: 32375228 PMCID: PMC7247563 DOI: 10.3390/ijms21093235] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 04/30/2020] [Accepted: 05/01/2020] [Indexed: 02/03/2023] Open
Abstract
Neuroserpin (NS) is a member of the serine protease inhibitors superfamily. Specific point mutations are responsible for its accumulation in the endoplasmic reticulum of neurons that leads to a pathological condition named familial encephalopathy with neuroserpin inclusion bodies (FENIB). Wild-type NS presents two N-glycosylation chains and does not form polymers in vivo, while non-glycosylated NS causes aberrant polymer accumulation in cell models. To date, all in vitro studies have been conducted on bacterially expressed NS, de facto neglecting the role of glycosylation in the biochemical properties of NS. Here, we report the expression and purification of human glycosylated NS (gNS) using a novel eukaryotic expression system, LEXSY. Our results confirm the correct N-glycosylation of wild-type gNS. The fold and stability of gNS are not altered compared to bacterially expressed NS, as demonstrated by the circular dichroism and intrinsic tryptophan fluorescence assays. Intriguingly, gNS displays a remarkably reduced polymerisation propensity compared to non-glycosylated NS, in keeping with what was previously observed for wild-type NS in vivo and in cell models. Thus, our results support the relevance of gNS as a new in vitro tool to study the molecular bases of FENIB.
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Affiliation(s)
- Cristina Visentin
- Dipartimento di Bioscienze, Università degli Studi di Milano, Via Celoria, 26, 20133 Milan, Italy; (C.V.); (L.B.); (B.M.S.); (M.B.)
| | - Luca Broggini
- Dipartimento di Bioscienze, Università degli Studi di Milano, Via Celoria, 26, 20133 Milan, Italy; (C.V.); (L.B.); (B.M.S.); (M.B.)
| | - Benedetta Maria Sala
- Dipartimento di Bioscienze, Università degli Studi di Milano, Via Celoria, 26, 20133 Milan, Italy; (C.V.); (L.B.); (B.M.S.); (M.B.)
- Science for Life Laboratory, Department of Medicine Solna, Karolinska Institute, and Division of Infectious Diseases, Karolinska University Hospital, Solna, SE-17176 Stockholm, Sweden;
- Department of Protein Science, School of Engineering Sciences in Chemistry, Biotechnology and Health, AlbaNova University Center, Royal Institute of Technology, SE-10691 Stockholm, Sweden
| | - Rosaria Russo
- Dipartimento di Fisiopatologia Medico-Chirurgica e dei Trapianti, Università degli Studi di Milano, Via Fratelli Cervi, 93, 20090 Segrate, Italy;
| | - Alberto Barbiroli
- Dipartimento di Scienze per gli Alimenti, la Nutrizione e l′Ambiente, Università degli Studi di Milano, Via Celoria, 2, 20133 Milan, Italy;
| | - Carlo Santambrogio
- Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano-Bicocca, Piazza dell’Ateneo Nuovo, 1, 20126 Milan, Italy;
| | - Simona Nonnis
- Departimento di Medicina Veterinaria, Università degli Studi di Milano, Via dell’Università, 6, 26900 Lodi, Italy;
| | - Anatoly Dubnovitsky
- Science for Life Laboratory, Department of Medicine Solna, Karolinska Institutet, and Division of Rheumatology, Karolinska University Hospital, Solna, SE-17176 Stockholm, Sweden;
| | - Martino Bolognesi
- Dipartimento di Bioscienze, Università degli Studi di Milano, Via Celoria, 26, 20133 Milan, Italy; (C.V.); (L.B.); (B.M.S.); (M.B.)
| | - Elena Miranda
- Dipartimento di Biologia e Biotecnologie ‘Charles Darwin’, and Istituto Pasteur - Fondazione Cenci-Bolognetti, Sapienza Università di Roma, Piazzale Aldo Moro, 5, 00185 Rome, Italy;
| | - Adnane Achour
- Science for Life Laboratory, Department of Medicine Solna, Karolinska Institute, and Division of Infectious Diseases, Karolinska University Hospital, Solna, SE-17176 Stockholm, Sweden;
| | - Stefano Ricagno
- Dipartimento di Bioscienze, Università degli Studi di Milano, Via Celoria, 26, 20133 Milan, Italy; (C.V.); (L.B.); (B.M.S.); (M.B.)
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9
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Ali MF, Kaushik A, Gupta D, Ansari S, Jairajpuri MA. Changes in strand 6B and helix B during neuroserpin inhibition: Implication in severity of clinical phenotype. BIOCHIMICA ET BIOPHYSICA ACTA. PROTEINS AND PROTEOMICS 2020; 1868:140363. [PMID: 31954927 DOI: 10.1016/j.bbapap.2020.140363] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 12/19/2019] [Accepted: 01/15/2020] [Indexed: 12/13/2022]
Abstract
Neuroserpin (NS) is predominantly expressed in brain and inhibits tissue-type plasminogen activator (tPA) with implications in brain development and memory. Nature of conformational change in pathological variants in strand 6B and helix B of NS that cause a relatively mild to severe epilepsy (and/or dementia) remains largely elusive. MD simulation with wild type (WT) NS, strand 6B and helix B variants indicated that substitution in this region affects the conformation of the strands 5B, 5A and reactive centre loop. Therefore, we designed variants of NS in strand 6B (I46D and F48S) and helix B (A54F, L55A and L55P) to investigate their role in tPA inhibition mechanism and propensity to aggregate. An interaction analysis showed disturbance of a hydrophobic patch centered at strands 5B, 6B and helix B in I46D and F48S but not in A54F, L55A, L55P and WT NS. Purified I46D, F48S and L55P variants showed decrease in fluorescence emission intensity but have similar α-helical content, however results of A54F and L55A were comparable to WT NS. Analysis of tPA inhibition showed marginal effect on A54F and L55A variant with tPA-NS complex formation. In contrast, I46D, F48S and L55P variants showed massive decrease in tPA inhibition, with no tPA-NS complex formation. Analysis of native PAGE under under polymerization condition showed prompt conversion of I46D, F48S and L55P to latent conformation but not A54F and L55A variants. Identification of these novel conformational changes will aid in the understanding of variable clinical phenotype of shutter region NS variants and other serpins.
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Affiliation(s)
- Mohammad Farhan Ali
- Protein Conformation and Enzymology Lab, Department of Biosciences, Jamia Millia Islamia (A Central University), New Delhi 110025, India
| | - Abhinav Kaushik
- Translational Bioinformatics Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Dinesh Gupta
- Translational Bioinformatics Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Shoyab Ansari
- Protein Conformation and Enzymology Lab, Department of Biosciences, Jamia Millia Islamia (A Central University), New Delhi 110025, India
| | - Mohamad Aman Jairajpuri
- Protein Conformation and Enzymology Lab, Department of Biosciences, Jamia Millia Islamia (A Central University), New Delhi 110025, India.
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10
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Eggenschwiler R, Patronov A, Hegermann J, Fráguas-Eggenschwiler M, Wu G, Cortnumme L, Ochs M, Antes I, Cantz T. A combined in silico and in vitro study on mouse Serpina1a antitrypsin-deficiency mutants. Sci Rep 2019; 9:7486. [PMID: 31097772 PMCID: PMC6522476 DOI: 10.1038/s41598-019-44043-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 05/07/2019] [Indexed: 01/15/2023] Open
Abstract
Certain point-mutations in the human SERPINA1-gene can cause severe α1-antitrypsin-deficiency (A1AT-D). Affected individuals can suffer from loss-of-function lung-disease and from gain-of-function liver-disease phenotypes. However, age of onset and severity of clinical appearance is heterogeneous amongst carriers, suggesting involvement of additional genetic and environmental factors. The generation of authentic A1AT-D mouse-models has been hampered by the complexity of the mouse Serpina1-gene locus and a model with concurrent lung and liver-disease is still missing. Here, we investigate point-mutations in the mouse Serpina1a antitrypsin-orthologue, which are homolog-equivalent to ones known to cause severe A1AT-D in human. We combine in silico and in vitro methods and we find that analyzed mutations do introduce potential disease-causing properties into Serpina1a. Finally, we show that introduction of the King’s-mutation causes inactivation of neutrophil elastase inhibitory-function in both, mouse and human antitrypsin, while the mouse Z-mutant retains activity. This work paves the path to generation of better A1AT-D mouse-models.
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Affiliation(s)
- Reto Eggenschwiler
- Research Group Translational Hepatology and Stem Cell Biology, Cluster of Excellence REBIRTH, Hannover Medical School, Hannover, 30625, Germany. .,Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hannover, 30625, Germany.
| | - Atanas Patronov
- Protein Modelling Group, Department of Life Sciences, Technical University Munich, Freising, 85354, Germany.,TUM School of Life Sciences, Center for Integrated Protein Science (CIPSM), Technical University Munich, Freising, 85354, Germany
| | - Jan Hegermann
- Research Core Unit Electron Microscopy, Hannover Medical School, Hannover, 30625, Germany.,Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, 30625, Germany.,Imaging Platform of the Cluster of Excellence REBIRTH, Hannover Medical School, Hannover, 30625, Germany
| | - Mariane Fráguas-Eggenschwiler
- Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hannover, 30625, Germany.,TWINCORE, Centre for Experimental and Clinical Infection Research, Hannover, 30625, Germany
| | - Guangming Wu
- Max Planck Institute for Molecular Biomedicine, Cell and Developmental Biology, Münster, 48149, Germany
| | - Leon Cortnumme
- Research Group Translational Hepatology and Stem Cell Biology, Cluster of Excellence REBIRTH, Hannover Medical School, Hannover, 30625, Germany.,Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hannover, 30625, Germany
| | - Matthias Ochs
- Research Core Unit Electron Microscopy, Hannover Medical School, Hannover, 30625, Germany.,Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, 30625, Germany.,Imaging Platform of the Cluster of Excellence REBIRTH, Hannover Medical School, Hannover, 30625, Germany.,Institute of Vegetative Anatomy Charité - Universitaetsmedizin Berlin, Berlin, 10115, Germany
| | - Iris Antes
- Protein Modelling Group, Department of Life Sciences, Technical University Munich, Freising, 85354, Germany.,TUM School of Life Sciences, Center for Integrated Protein Science (CIPSM), Technical University Munich, Freising, 85354, Germany
| | - Tobias Cantz
- Research Group Translational Hepatology and Stem Cell Biology, Cluster of Excellence REBIRTH, Hannover Medical School, Hannover, 30625, Germany. .,Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hannover, 30625, Germany. .,Max Planck Institute for Molecular Biomedicine, Cell and Developmental Biology, Münster, 48149, Germany.
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11
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Ali MF, Kaushik A, Kapil C, Gupta D, Jairajpuri MA. A hydrophobic patch surrounding Trp154 in human neuroserpin controls the helix F dynamics with implications in inhibition and aggregation. Sci Rep 2017; 7:42987. [PMID: 28230174 PMCID: PMC5322333 DOI: 10.1038/srep42987] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 01/17/2017] [Indexed: 01/23/2023] Open
Abstract
Neuroserpin (NS) mediated inhibition of tissue-type plasminogen activator (tPA) is important for brain development, synapse formation and memory. Aberrations in helix F and β-sheet A movement during inhibition can directly lead to epilepsy or dementia. Conserved W154 residue in a hydrophobic patch between helix F and β-sheet A is ideally placed to control their movement during inhibition. Molecular Dynamics (MD) simulation on wild type (WT) NS and its two variants (W154A and W154P) demonstrated partial deformation in helix F and conformational differences in strands 1A and 2A only in W154P. A fluorescence and Circular Dichroism (CD) analysis with purified W154 variants revealed a significant red-shift and an increase in α-helical content in W154P as compared to W154A and WT NS. Kinetics of tPA inhibition showed a decline in association rates (ka) for W154A as compared to WT NS with indication of complex formation. Appearance of cleaved without complex formation in W154P indicates that the variant acts as substrate due to conformational misfolding around helix F. Both the variants however showed increased rate of aggregation as compared to WT NS. The hydrophobic patch identified in this study may have importance in helix F dynamics of NS.
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Affiliation(s)
- Mohammad Farhan Ali
- Protein Conformation and Enzymology Lab, Department of Biosciences, Jamia Millia Islamia (A Central University), New Delhi-110025, India
| | - Abhinav Kaushik
- Translational Bioinformatics Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), Aruna Asaf Ali Marg, New Delhi-110067, India
| | - Charu Kapil
- Protein Conformation and Enzymology Lab, Department of Biosciences, Jamia Millia Islamia (A Central University), New Delhi-110025, India
| | - Dinesh Gupta
- Translational Bioinformatics Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), Aruna Asaf Ali Marg, New Delhi-110067, India
| | - Mohamad Aman Jairajpuri
- Protein Conformation and Enzymology Lab, Department of Biosciences, Jamia Millia Islamia (A Central University), New Delhi-110025, India
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12
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Saga G, Sessa F, Barbiroli A, Santambrogio C, Russo R, Sala M, Raccosta S, Martorana V, Caccia S, Noto R, Moriconi C, Miranda E, Grandori R, Manno M, Bolognesi M, Ricagno S. Embelin binds to human neuroserpin and impairs its polymerisation. Sci Rep 2016; 6:18769. [PMID: 26732982 PMCID: PMC4702122 DOI: 10.1038/srep18769] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 11/26/2015] [Indexed: 01/07/2023] Open
Abstract
Neuroserpin (NS) is a serpin inhibitor of tissue plasminogen activator (tPA) in the brain. The polymerisation of NS pathologic mutants is responsible for a genetic dementia known as familial encephalopathy with neuroserpin inclusion bodies (FENIB). So far, a pharmacological treatment of FENIB, i.e. an inhibitor of NS polymerisation, remains an unmet challenge. Here, we present a biophysical characterisation of the effects caused by embelin (EMB a small natural compound) on NS conformers and NS polymerisation. EMB destabilises all known NS conformers, specifically binding to NS molecules with a 1:1 NS:EMB molar ratio without unfolding the NS fold. In particular, NS polymers disaggregate in the presence of EMB, and their formation is prevented. The NS/EMB complex does not inhibit tPA proteolytic activity. Both effects are pharmacologically relevant: firstly by inhibiting the NS polymerisation associated to FENIB, and secondly by potentially antagonizing metastatic processes facilitated by NS activity in the brain.
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Affiliation(s)
- Giorgia Saga
- Dipartimento di Bioscienze and CIMAINA, Università degli Studi di Milano, Milan, Italy
| | - Fabio Sessa
- Dipartimento di Bioscienze and CIMAINA, Università degli Studi di Milano, Milan, Italy
| | - Alberto Barbiroli
- Dipartimento di Scienze per gli Alimenti, la Nutrizione e l′Ambiente, Università degli Studi di Milano, Milan, Italy
| | - Carlo Santambrogio
- Dipartimento di Biotecnologie e Bioscienze, Università Milano-Bicocca, Milan, Italy
| | - Rosaria Russo
- Dipartimento di Fisiopatologia Medico-Chirurgica e dei Trapianti, Università degli Studi di MilanoItaly
| | - Michela Sala
- Dipartimento di Biotecnologie e Bioscienze, Università Milano-Bicocca, Milan, Italy
| | - Samuele Raccosta
- Istituto di Biofisica, National Research Council of Italy, Palermo, Italy
| | - Vincenzo Martorana
- Istituto di Biofisica, National Research Council of Italy, Palermo, Italy
| | - Sonia Caccia
- Dipartimento di Biotecnologie Mediche e Medicina traslazionale, Università degli Studi di Milano, Milan, Italy
| | - Rosina Noto
- Istituto di Biofisica, National Research Council of Italy, Palermo, Italy
| | - Claudia Moriconi
- Dipartimento di Biologia e Biotecnologie Charles Darwin, and Istituto Pasteur – Fondazione Cenci-Bolognetti, Sapienza Università di Roma, Rome, Italy
| | - Elena Miranda
- Dipartimento di Biologia e Biotecnologie Charles Darwin, and Istituto Pasteur – Fondazione Cenci-Bolognetti, Sapienza Università di Roma, Rome, Italy
| | - Rita Grandori
- Dipartimento di Biotecnologie e Bioscienze, Università Milano-Bicocca, Milan, Italy
| | - Mauro Manno
- Istituto di Biofisica, National Research Council of Italy, Palermo, Italy
| | - Martino Bolognesi
- Dipartimento di Bioscienze and CIMAINA, Università degli Studi di Milano, Milan, Italy
- Istituto di Biofisica, National Research Council of Italy, c/o Dipartimento di Bioscienze, Università degli Studi di Milano, Milan, Italy
| | - Stefano Ricagno
- Dipartimento di Bioscienze and CIMAINA, Università degli Studi di Milano, Milan, Italy
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13
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Noto R, Randazzo L, Raccosta S, Caccia S, Moriconi C, Miranda E, Martorana V, Manno M. The stability and activity of human neuroserpin are modulated by a salt bridge that stabilises the reactive centre loop. Sci Rep 2015; 5:13666. [PMID: 26329378 PMCID: PMC4556959 DOI: 10.1038/srep13666] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2015] [Accepted: 08/03/2015] [Indexed: 11/26/2022] Open
Abstract
Neuroserpin (NS) is an inhibitory protein belonging to the serpin family and involved in several pathologies, including the dementia Familial Encephalopathy with Neuroserpin Inclusion Bodies (FENIB), a genetic neurodegenerative disease caused by accumulation of NS polymers. Our Molecular Dynamics simulations revealed the formation of a persistent salt bridge between Glu289 on strand s2C and Arg362 on the Reactive Centre Loop (RCL), a region important for the inhibitory activity of NS. Here, we validated this structural feature by simulating the Glu289Ala mutant, where the salt bridge is not present. Further, MD predictions were tested in vitro by purifying recombinant Glu289Ala NS from E. coli. The thermal and chemical stability along with the polymerisation propensity of both Wild Type and Glu289Ala NS were characterised by circular dichroism, emission spectroscopy and non-denaturant gel electrophoresis, respectively. The activity of both variants against the main target protease, tissue-type plasminogen activator (tPA), was assessed by SDS-PAGE and chromogenic kinetic assay. Our results showed that deletion of the salt bridge leads to a moderate but clear reduction of the overall protein stability and activity.
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Affiliation(s)
- Rosina Noto
- National Research Council of Italy, Institute of Biophysics, Palermo, Italy
| | - Loredana Randazzo
- National Research Council of Italy, Institute of Biophysics, Palermo, Italy
| | - Samuele Raccosta
- National Research Council of Italy, Institute of Biophysics, Palermo, Italy
| | - Sonia Caccia
- Department of Medical Biotechnologies and Translational Medicine, University of Milan, Milan, Italy
| | - Claudia Moriconi
- Department of Biology and Biotechnologies “Charles Darwin” and Pasteur Institute - Cenci Bolognetti Foundation, Sapienza University of Rome, Rome, Italy
| | - Elena Miranda
- Department of Biology and Biotechnologies “Charles Darwin” and Pasteur Institute - Cenci Bolognetti Foundation, Sapienza University of Rome, Rome, Italy
| | - Vincenzo Martorana
- National Research Council of Italy, Institute of Biophysics, Palermo, Italy
| | - Mauro Manno
- National Research Council of Italy, Institute of Biophysics, Palermo, Italy
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14
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Caccia S, Ricagno S, Bolognesi M. Molecular bases of neuroserpin function and pathology. Biomol Concepts 2015; 1:117-30. [PMID: 25961991 DOI: 10.1515/bmc.2010.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Serpins build a large and evolutionary widespread protein superfamily, hosting members that are mainly Ser-protease inhibitors. Typically, serpins display a conserved core domain composed of three main β-sheets and 9-10 α-helices, for a total of approximately 350 amino acids. Neuroserpin (NS) is mostly expressed in neurons and in the central and peripheral nervous systems, where it targets tissue-type plasminogen activator. NS activity is relevant for axogenesis, synaptogenesis and synaptic plasticity. Five (single amino acid) NS mutations are associated with severe neurodegenerative disease in man, leading to early onset dementia, epilepsy and neuronal death. The functional aspects of NS protease inhibition are linked to the presence of a long exposed loop (reactive center loop, RCL) that acts as bait for the incoming partner protease. Large NS conformational changes, associated with the cleavage of the RCL, trap the protease in an acyl-enzyme complex. Contrary to other serpins, this complex has a half-life of approximately 10 min. Conformational flexibility is held to be at the bases of NS polymerization leading to Collins bodies intracellular deposition and neuronal damage in the pathological NS variants. Two main general mechanisms of serpin polymerization are currently discussed. Both models require the swapping of the RCL among neighboring serpin molecules. Specific differences in the size of swapped regions, as well as differences in the folding stage at which polymerization can occur, distinguish the two models. The results provided by recent crystallographic and biophysical studies allow rationalization of the functional and pathological roles played by NS based on the analysis of four three-dimensional structures.
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15
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Noto R, Santangelo MG, Levantino M, Cupane A, Mangione MR, Parisi D, Ricagno S, Bolognesi M, Manno M, Martorana V. Functional and dysfunctional conformers of human neuroserpin characterized by optical spectroscopies and Molecular Dynamics. BIOCHIMICA ET BIOPHYSICA ACTA 2015; 1854:110-7. [PMID: 25450507 PMCID: PMC4332418 DOI: 10.1016/j.bbapap.2014.10.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 09/04/2014] [Accepted: 10/03/2014] [Indexed: 12/12/2022]
Abstract
Neuroserpin (NS) is a serine protease inhibitor (SERPIN) involved in different neurological pathologies, including the Familial Encephalopathy with Neuroserpin Inclusion Bodies (FENIB), related to the aberrant polymerization of NS mutants. Here we present an in vitro and in silico characterization of native neuroserpin and its dysfunctional conformation isoforms: the proteolytically cleaved conformer, the inactive latent conformer, and the polymeric species. Based on circular dichroism and fluorescence spectroscopy, we present an experimental validation of the latent model and highlight the main structural features of the different conformers. In particular, emission spectra of aromatic residues yield distinct conformational fingerprints, that provide a novel and simple spectroscopic tool for selecting serpin conformers in vitro. Based on the structural relationship between cleaved and latent serpins, we propose a structural model for latent NS, for which an experimental crystallographic structure is lacking. Molecular Dynamics simulations suggest that NS conformational stability and flexibility arise from a spatial distribution of intramolecular salt-bridges and hydrogen bonds.
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Affiliation(s)
- Rosina Noto
- Institute of Biophysics, National Research Council of Italy, Palermo, Italy
| | | | - Matteo Levantino
- Department of Physics and Chemistry, University of Palermo, Palermo, Italy
| | - Antonio Cupane
- Department of Physics and Chemistry, University of Palermo, Palermo, Italy
| | | | - Daniele Parisi
- Institute of Biophysics, National Research Council of Italy, Palermo, Italy; Department of Biosciences, Institute of Biophysics CNR, Italy and CIMAINA, University of Milano, Milan, Italy
| | - Stefano Ricagno
- Department of Biosciences, Institute of Biophysics CNR, Italy and CIMAINA, University of Milano, Milan, Italy
| | - Martino Bolognesi
- Department of Biosciences, Institute of Biophysics CNR, Italy and CIMAINA, University of Milano, Milan, Italy
| | - Mauro Manno
- Institute of Biophysics, National Research Council of Italy, Palermo, Italy.
| | - Vincenzo Martorana
- Institute of Biophysics, National Research Council of Italy, Palermo, Italy
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16
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Lee TW, Yang ASP, Brittain T, Birch NP. An analysis approach to identify specific functional sites in orthologous proteins using sequence and structural information: application to neuroserpin reveals regions that differentially regulate inhibitory activity. Proteins 2015; 83:135-52. [PMID: 25363759 DOI: 10.1002/prot.24711] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Revised: 10/22/2014] [Accepted: 10/27/2014] [Indexed: 01/12/2023]
Abstract
The analysis of sequence conservation is commonly used to predict functionally important sites in proteins. We have developed an approach that first identifies highly conserved sites in a set of orthologous sequences using a weighted substitution-matrix-based conservation score and then filters these conserved sites based on the pattern of conservation present in a wider alignment of sequences from the same family and structural information to identify surface-exposed sites. This allows us to detect specific functional sites in the target protein and exclude regions that are likely to be generally important for the structure or function of the wider protein family. We applied our method to two members of the serpin family of serine protease inhibitors. We first confirmed that our method successfully detected the known heparin binding site in antithrombin while excluding residues known to be generally important in the serpin family. We next applied our sequence analysis approach to neuroserpin and used our results to guide site-directed polyalanine mutagenesis experiments. The majority of the mutant neuroserpin proteins were found to fold correctly and could still form inhibitory complexes with tissue plasminogen activator (tPA). Kinetic analysis of tPA inhibition, however, revealed altered inhibitory kinetics in several of the mutant proteins, with some mutants showing decreased association with tPA and others showing more rapid dissociation of the covalent complex. Altogether, these results confirm that our sequence analysis approach is a useful tool that can be used to guide mutagenesis experiments for the detection of specific functional sites in proteins.
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Affiliation(s)
- Tet Woo Lee
- School of Biological Sciences and Centre for Brain Research, University of Auckland, Auckland, New Zealand
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17
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Tan L, Perez J, Mela M, Miranda E, Burling KA, Rouhani FN, DeMeo DL, Haq I, Irving JA, Ordóñez A, Dickens JA, Brantly M, Marciniak SJ, Alexander GJM, Gooptu B, Lomas DA. Characterising the association of latency with α(1)-antitrypsin polymerisation using a novel monoclonal antibody. Int J Biochem Cell Biol 2014; 58:81-91. [PMID: 25462157 PMCID: PMC4305080 DOI: 10.1016/j.biocel.2014.11.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Revised: 10/13/2014] [Accepted: 11/04/2014] [Indexed: 11/27/2022]
Abstract
α1-Antitrypsin is primarily synthesised in the liver, circulates to the lung and protects pulmonary tissues from proteolytic damage. The Z mutant (Glu342Lys) undergoes inactivating conformational change and polymerises. Polymers are retained within the hepatocyte endoplasmic reticulum (ER) in homozygous (PiZZ) individuals, predisposing the individuals to hepatic cirrhosis and emphysema. Latency is an analogous process of inactivating, intra-molecular conformational change and may co-occur with polymerisation. However, the relationship between latency and polymerisation remained unexplored in the absence of a suitable probe. We have developed a novel monoclonal antibody specific for latent α1-antitrypsin and used it in combination with a polymer-specific antibody, to assess the association of both conformers in vitro, in disease and during augmentation therapy. In vitro kinetics analysis showed polymerisation dominated the pathway but latency could be promoted by stabilising monomeric α1-antitrypsin. Polymers were extensively produced in hepatocytes and a cell line expressing Z α1-antitrypsin but the latent protein was not detected despite manipulation of the secretory pathway. However, α1-antitrypsin augmentation therapy contains latent α1-antitrypsin, as did the plasma of 63/274 PiZZ individuals treated with augmentation therapy but 0/264 who were not receiving this medication (p<10(-14)). We conclude that latent α1-antitrypsin is a by-product of the polymerisation pathway, that the intracellular folding environment is resistant to formation of the latent conformer but that augmentation therapy introduces latent α1-antitrypsin into the circulation. A suite of monoclonal antibodies and methodologies developed in this study can characterise α1-antitrypsin folding and conformational transitions, and screen methods to improve augmentation therapy.
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Affiliation(s)
- Lu Tan
- Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Cambridge, UK; Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland
| | - Juan Perez
- Department of Cell Biology, Genetics and Physiology, University of Málaga, Málaga, Spain
| | - Marianna Mela
- Division of Gastroenterology & Hepatology, University Department of Medicine, Cambridge University Hospitals, Cambridge, UK
| | - Elena Miranda
- Department of Biology and Biotechnologies Charles Darwin and Pasteur Institute-Cenci Bolognetti Foundation-University of Rome La Sapienza, Rome, Italy
| | - Keith A Burling
- Core Biochemical Assay Laboratory, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Farshid N Rouhani
- Department of Medicine, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Dawn L DeMeo
- Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, MA, USA
| | - Imran Haq
- Wolfson Institute for Biomedical Research, University College London, London, UK
| | - James A Irving
- Wolfson Institute for Biomedical Research, University College London, London, UK
| | - Adriana Ordóñez
- Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Cambridge, UK
| | - Jennifer A Dickens
- Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Cambridge, UK
| | - Mark Brantly
- Department of Medicine, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Stefan J Marciniak
- Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Cambridge, UK
| | - Graeme J M Alexander
- Division of Gastroenterology & Hepatology, University Department of Medicine, Cambridge University Hospitals, Cambridge, UK
| | - Bibek Gooptu
- Division of Asthma, Allergy and Lung Biology, King's College London, Guy's Hospital, 5th Floor, Tower Wing, London, UK.
| | - David A Lomas
- Wolfson Institute for Biomedical Research, University College London, London, UK.
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18
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Mandas A, Dessì S. Mononuclear cells in dementia. Clin Chim Acta 2014; 431:278-87. [DOI: 10.1016/j.cca.2014.02.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2013] [Revised: 02/15/2014] [Accepted: 02/18/2014] [Indexed: 12/14/2022]
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19
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Trelle MB, Hirschberg D, Jansson A, Ploug M, Roepstorff P, Andreasen PA, Jørgensen TJD. Hydrogen/deuterium exchange mass spectrometry reveals specific changes in the local flexibility of plasminogen activator inhibitor 1 upon binding to the somatomedin B domain of vitronectin. Biochemistry 2012; 51:8256-66. [PMID: 22957734 DOI: 10.1021/bi3008998] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The native fold of plasminogen activator inhibitor 1 (PAI-1) represents an active metastable conformation that spontaneously converts to an inactive latent form. Binding of the somatomedin B domain (SMB) of the endogenous cofactor vitronectin to PAI-1 delays the transition to the latent state and increases the thermal stability of the protein dramatically. We have used hydrogen/deuterium exchange mass spectrometry to assess the inherent structural flexibility of PAI-1 and to monitor the changes induced by SMB binding. Our data show that the PAI-1 core consisting of β-sheet B is rather protected against exchange with the solvent, while the remainder of the molecule is more dynamic. SMB binding causes a pronounced and widespread stabilization of PAI-1 that is not confined to the binding interface with SMB. We further explored the local structural flexibility in a mutationally stabilized PAI-1 variant (14-1B) as well as the effect of stabilizing antibody Mab-1 on wild-type PAI-1. The three modes of stabilizing PAI-1 (SMB, Mab-1, and the mutations in 14-1B) all cause a delayed latency transition, and this effect was accompanied by unique signatures on the flexibility of PAI-1. Reduced flexibility in the region around helices B, C, and I was seen in all three cases, which suggests an involvement of this region in mediating structural flexibility necessary for the latency transition. These data therefore add considerable depth to our current understanding of the local structural flexibility in PAI-1 and provide novel indications of regions that may affect the functional stability of PAI-1.
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Affiliation(s)
- Morten Beck Trelle
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
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Noto R, Santangelo MG, Ricagno S, Mangione MR, Levantino M, Pezzullo M, Martorana V, Cupane A, Bolognesi M, Manno M. The tempered polymerization of human neuroserpin. PLoS One 2012; 7:e32444. [PMID: 22412873 PMCID: PMC3295756 DOI: 10.1371/journal.pone.0032444] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Accepted: 01/31/2012] [Indexed: 11/24/2022] Open
Abstract
Neuroserpin, a member of the serpin protein superfamily, is an inhibitor of proteolytic activity that is involved in pathologies such as ischemia, Alzheimer's disease, and Familial Encephalopathy with Neuroserpin Inclusion Bodies (FENIB). The latter belongs to a class of conformational diseases, known as serpinopathies, which are related to the aberrant polymerization of serpin mutants. Neuroserpin is known to polymerize, even in its wild type form, under thermal stress. Here, we study the mechanism of neuroserpin polymerization over a wide range of temperatures by different techniques. Our experiments show how the onset of polymerization is dependent on the formation of an intermediate monomeric conformer, which then associates with a native monomer to yield a dimeric species. After the formation of small polymers, the aggregation proceeds via monomer addition as well as polymer-polymer association. No further secondary mechanism takes place up to very high temperatures, thus resulting in the formation of neuroserpin linear polymeric chains. Most interesting, the overall aggregation is tuned by the co-occurrence of monomer inactivation (i.e. the formation of latent neuroserpin) and by a mechanism of fragmentation. The polymerization kinetics exhibit a unique modulation of the average mass and size of polymers, which might suggest synchronization among the different processes involved. Thus, fragmentation would control and temper the aggregation process, instead of enhancing it, as typically observed (e.g.) for amyloid fibrillation.
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Affiliation(s)
- Rosina Noto
- Institute of Biophysics, National Research Council of Italy, Palermo, Italy
| | | | - Stefano Ricagno
- Department of Biomolecular Sciences and Biotechnology, Institute of Biophysics CNR and CIMAINA, University of Milano, Milan, Italy
| | | | | | - Margherita Pezzullo
- Department of Biomolecular Sciences and Biotechnology, Institute of Biophysics CNR and CIMAINA, University of Milano, Milan, Italy
| | - Vincenzo Martorana
- Institute of Biophysics, National Research Council of Italy, Palermo, Italy
| | - Antonio Cupane
- Department of Physics, University of Palermo, Palermo, Italy
| | - Martino Bolognesi
- Department of Biomolecular Sciences and Biotechnology, Institute of Biophysics CNR and CIMAINA, University of Milano, Milan, Italy
| | - Mauro Manno
- Institute of Biophysics, National Research Council of Italy, Palermo, Italy
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Santangelo MG, Noto R, Levantino M, Cupane A, Ricagno S, Pezzullo M, Bolognesi M, Mangione MR, Martorana V, Manno M. On the molecular structure of human neuroserpin polymers. Proteins 2012; 80:8-13. [PMID: 22072549 DOI: 10.1002/prot.23197] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Revised: 09/04/2011] [Accepted: 09/14/2011] [Indexed: 11/12/2022]
Abstract
The polymerization of serpins is at the root of a large class of diseases; the molecular structure of serpin polymers has been recently debated. In this work, we study the polymerization kinetics of human neuroserpin by Fourier Transform Infra Red spectroscopy and by time-lapse Size Exclusion Chromatography. First, we show that two distinct neuroserpin polymers, formed at 45 and 85°C, display the same isosbestic points in the Amide I' band, and therefore share common secondary structure features. We also find a concentration independent polymerization rate at 45°C suggesting that the polymerization rate-limiting step is the formation of an activated monomeric species. The polymer structures are consistent with a model that predicts the bare insertion of portions of the reactive center loop into the A β-sheet of neighboring serpin molecule, although with different extents at 45 and 85°C.
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22
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Sarkar A, Zhou C, Meklemburg R, Wintrode P. Local conformational flexibility provides a basis for facile polymer formation in human neuroserpin. Biophys J 2011; 101:1758-65. [PMID: 21961602 PMCID: PMC3183757 DOI: 10.1016/j.bpj.2011.08.037] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Revised: 08/23/2011] [Accepted: 08/25/2011] [Indexed: 10/17/2022] Open
Abstract
Neuroserpin is a regulator of neuronal growth and plasticity. Like other members of the serpin family, neuroserpin undergoes a large conformational change as part of its function. Unlike other serpins such as α(1)-antitrypsin, wild-type neuroserpin will polymerize under near-physiological conditions, and will spontaneously transition to the latent state. To probe the origins of this conformational lability, we have performed hydrogen exchange measurements and molecular-dynamics simulations on human neuroserpin. Hydrogen exchange indicates that neuroserpin has greater flexibility in the breach region and in β-strand 1C compared with α(1)-antitrypsin. Molecular-dynamics simulations show that the distance between the top of β-strands 3 and 5A averages 4.6 Å but becomes as large as 7.5 Å in neuroserpin while it remains stable at ∼3.5 Å in α(1)-antitrypsin. Further simulations show that the stabilizing S340A mutation suppresses these fluctuations in neuroserpin. The first principal component calculated from the simulations shows a movement of helix F away from the face of β-sheet A in neuroserpin while no such movement is evident in α(1)-antitrypsin. The increased mobility of these regions in neuroserpin relative to α(1)-antitrypsin provides a basis for neuroserpin's increased tendency toward the formation of polymers and/or the latent state.
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Affiliation(s)
| | | | | | - Patrick L. Wintrode
- Department of Physiology & Biophysics, Case Western Reserve University, Cleveland, Ohio
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23
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Irving JA, Ekeowa UI, Belorgey D, Haq I, Gooptu B, Miranda E, Pérez J, Roussel BD, Ordóñez A, Dalton LE, Thomas SE, Marciniak SJ, Parfrey H, Chilvers ER, Teckman JH, Alam S, Mahadeva R, Rashid ST, Vallier L, Lomas DA. The serpinopathies studying serpin polymerization in vivo. Methods Enzymol 2011; 501:421-66. [PMID: 22078544 DOI: 10.1016/b978-0-12-385950-1.00018-3] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The serpinopathies result from point mutations in members of the serine protease inhibitor or serpin superfamily. They are characterized by the formation of ordered polymers that are retained within the cell of synthesis. This causes disease by a "toxic gain of function" from the accumulated protein and a "loss of function" as a result of the deficiency of inhibitors that control important proteolytic cascades. The serpinopathies are exemplified by the Z (Glu342Lys) mutant of α₁-antitrypsin that results in the retention of ordered polymers within the endoplasmic reticulum of hepatocytes. These polymers form the intracellular inclusions that are associated with neonatal hepatitis, cirrhosis, and hepatocellular carcinoma. A second example results from mutations in the neurone-specific serpin-neuroserpin to form ordered polymers that are retained as inclusions within subcortical neurones as Collins' bodies. These inclusions underlie the autosomal dominant dementia familial encephalopathy with neuroserpin inclusion bodies or FENIB. There are different pathways to polymer formation in vitro but not all form polymers that are relevant in vivo. It is therefore essential that protein-based structural studies are interpreted in the context of human samples and cell and animal models of disease. We describe here the biochemical techniques, monoclonal antibodies, cell biology, animal models, and stem cell technology that are useful to characterize the serpin polymers that form in vivo.
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Affiliation(s)
- James A Irving
- Department of Medicine, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
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24
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Belorgey D, Irving JA, Ekeowa UI, Freeke J, Roussel BD, Miranda E, Pérez J, Robinson CV, Marciniak SJ, Crowther DC, Michel CH, Lomas DA. Characterisation of serpin polymers in vitro and in vivo. Methods 2010; 53:255-66. [PMID: 21115126 DOI: 10.1016/j.ymeth.2010.11.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2010] [Accepted: 11/21/2010] [Indexed: 10/18/2022] Open
Abstract
Neuroserpin is a member of the serine protease inhibitor or serpin superfamily of proteins. It is secreted by neurones and plays an important role in the regulation of tissue plasminogen activator at the synapse. Point mutations in the neuroserpin gene cause the autosomal dominant dementia familial encephalopathy with neuroserpin inclusion bodies or FENIB. This is one of a group of disorders caused by mutations in the serpins that are collectively known as the serpinopathies. Others include α(1)-antitrypsin deficiency and deficiency of C1 inhibitor, antithrombin and α(1)-antichymotrypsin. The serpinopathies are characterised by delays in protein folding and the retention of ordered polymers of the mutant serpin within the cell of synthesis. The clinical phenotype results from either a toxic gain of function from the inclusions or a loss of function, as there is insufficient protease inhibitor to regulate important proteolytic cascades. We describe here the methods required to characterise the polymerisation of neuroserpin and draw parallels with the polymerisation of α(1)-antitrypsin. It is important to recognise that the conditions in which experiments are performed will have a major effect on the findings. For example, incubation of monomeric serpins with guanidine or urea will produce polymers that are not found in vivo. The characterisation of the pathological polymers requires heating of the folded protein or alternatively the assessment of ordered polymers from cell and animal models of disease or from the tissues of humans who carry the mutation.
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Affiliation(s)
- Didier Belorgey
- Dept. of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, UK
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26
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Ricagno S, Pezzullo M, Barbiroli A, Manno M, Levantino M, Santangelo MG, Bonomi F, Bolognesi M. Two latent and two hyperstable polymeric forms of human neuroserpin. Biophys J 2010; 99:3402-11. [PMID: 21081089 PMCID: PMC2980742 DOI: 10.1016/j.bpj.2010.09.021] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Revised: 09/08/2010] [Accepted: 09/09/2010] [Indexed: 02/02/2023] Open
Abstract
Human neuroserpin (hNS) is a serine protease inhibitor that belongs to the serpin superfamily and is expressed in nervous tissues. The serpin fold is generally characterized by a long exposed loop, termed the reactive center loop, that acts as bait for the target protease. Intramolecular insertion of the reactive center loop into the main serpin β-sheet leads to the serpin latent form. As with other known serpins, hNS pathological mutants have been shown to accumulate as polymers composed of quasi-native protein molecules. Although hNS polymerization has been intensely studied, a general agreement about serpin polymer organization is still lacking. Here we report a biophysical characterization of native hNS that is shown to undergo two distinct conformational transitions, at 55°C and 85°C, both leading to distinct latent and polymeric species. The latent and polymer hNS forms obtained at 45°C and 85°C differ in their chemical and thermal stabilities; furthermore, the hNS polymers also differ in size and morphology. Finally, the 85°C polymer shows a higher content of intermolecular β-sheet interactions than the 45°C polymer. Together, these results suggest a more complex conformational scenario than was previously envisioned, and, in a general context, may help reconcile the current contrasting views on serpin polymerization.
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Affiliation(s)
- Stefano Ricagno
- Dipartimento di Scienze Biomolecolari e Biotecnologie, Centro Interdisciplinare Materiali e Interfacce Nanostrutturati, Università di Milano, Milan, Italy
- Dipartimento di Biochimica, Università di Pavia, Pavia, Italy
- Laboratori di Biotecnologie, Istituto Di Ricovero e Cura a Carattere Scientifico Fondazione Policlinico San Matteo, Pavia, Italy
| | - Margherita Pezzullo
- Dipartimento di Scienze Biomolecolari e Biotecnologie, Centro Interdisciplinare Materiali e Interfacce Nanostrutturati, Università di Milano, Milan, Italy
| | - Alberto Barbiroli
- Sezione di Biochimica, Dipartimento di Scienze Molecolari Agroalimentari, Università di Milano, Milan, Italy
| | - Mauro Manno
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, CNR, Palermo, Italy
| | - Matteo Levantino
- Dipartimento di Scienze Fisiche ed Astronomiche, Università of Palermo, Palermo, Italy
| | | | - Francesco Bonomi
- Sezione di Biochimica, Dipartimento di Scienze Molecolari Agroalimentari, Università di Milano, Milan, Italy
| | - Martino Bolognesi
- Dipartimento di Scienze Biomolecolari e Biotecnologie, Centro Interdisciplinare Materiali e Interfacce Nanostrutturati, Università di Milano, Milan, Italy
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27
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Takehara S, Zhang J, Yang X, Takahashi N, Mikami B, Onda M. Refolding and polymerization pathways of neuroserpin. J Mol Biol 2010; 403:751-62. [PMID: 20691191 DOI: 10.1016/j.jmb.2010.07.047] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2010] [Revised: 07/21/2010] [Accepted: 07/25/2010] [Indexed: 11/29/2022]
Abstract
Neuroserpin is a member of the serpin superfamily, and its mutants are retained within the endoplasmic reticulum of neurons as ordered polymers in association with dementia. It has been proposed that neuroserpin polymers are formed by a conformational change in the folded protein. However, an alternative model whereby polymers are formed during protein folding rather than from the folded protein has recently been proposed. We investigated the refolding and polymerization pathways of wild-type neuroserpin (WT) and of the pathogenic mutants S49P and H338R. Upon refolding, denatured WT immediately formed an initial refolding intermediate I(IN) and then underwent further refolding to the native form through a late refolding intermediate, I(R). The late-onset mutant S49P was also able to refold to the native form through I(IN) and I(R), but the final refolding step proceeded at a slower rate and with a lower refolding yield as compared with WT. The early-onset mutant H338R formed I(R) through the same pathway as S49P, but the protein could not attain the native state and remained as I(R). The I(R)s of the mutants had a long lifespan at 4 °C and thus were purified and characterized. Strikingly, when incubated under physiological conditions, I(R) formed ordered polymers with essentially the same properties as the polymers formed from the native protein. The results show that the mutants have a greater tendency to form polymers during protein folding than to form polymers from the folded protein. Our finding provides insights into biochemical approaches to treating serpinopathies by targeting a polymerogenic folding intermediate.
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Affiliation(s)
- Sayaka Takehara
- Division of Applied Life Sciences, The Graduate School of Agriculture, Kyoto University, Uji, Japan
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28
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Belorgey D, Hägglöf P, Onda M, Lomas DA. pH-dependent stability of neuroserpin is mediated by histidines 119 and 138; implications for the control of beta-sheet A and polymerization. Protein Sci 2010; 19:220-8. [PMID: 19953505 PMCID: PMC2865726 DOI: 10.1002/pro.299] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2009] [Revised: 09/24/2009] [Accepted: 11/16/2009] [Indexed: 11/09/2022]
Abstract
Neuroserpin is a member of the serpin superfamily. Point mutations in the neuroserpin gene underlie the autosomal dominant dementia, familial encephalopathy with neuroserpin inclusion bodies. This is characterized by the retention of ordered polymers of neuroserpin within the endoplasmic reticulum of neurons. pH has been shown to affect the propensity of several serpins to form polymers. In particular, low pH favors the formation of polymers of both alpha(1)-antitrypsin and antithrombin. We report here opposite effects in neuroserpin, with a striking resistance to polymer formation at acidic pH. Mutation of specific histidine residues showed that this effect is not attributable to the shutter domain histidine as would be predicted by analogy with other serpins. Indeed, mutation of the shutter domain His338 decreased neuroserpin stability but had no effect on the pH dependence of polymerization when compared with the wild-type protein. In contrast, mutation of His119 or His138 reduced the polymerization of neuroserpin at both acidic and neutral pH. These residues are at the lower pole of neuroserpin and provide a novel mechanism to control the opening of beta-sheet A and hence polymerization. This mechanism is likely to have evolved to protect neuroserpin from the acidic environment of the secretory granules.
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Affiliation(s)
- Didier Belorgey
- Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Cambridge CB2 0XY, United Kingdom.
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29
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Chiou A, Hägglöf P, Orte A, Chen AY, Dunne PD, Belorgey D, Karlsson-Li S, Lomas DA, Klenerman D. Probing neuroserpin polymerization and interaction with amyloid-beta peptides using single molecule fluorescence. Biophys J 2009; 97:2306-15. [PMID: 19843463 PMCID: PMC2764104 DOI: 10.1016/j.bpj.2009.07.057] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2009] [Revised: 07/10/2009] [Accepted: 07/28/2009] [Indexed: 10/20/2022] Open
Abstract
Neuroserpin is a member of the serine proteinase inhibitor superfamily. It can undergo a conformational transition to form polymers that are associated with the dementia familial encephalopathy with neuroserpin inclusion bodies and the wild-type protein can inhibit the toxicity of amyloid-beta peptides in Alzheimer's disease. We have used a single molecule fluorescence method, two color coincidence detection, to determine the rate-limiting steps of the early stages of the polymerization of fluorophore-labeled neuroserpin and have assessed how this process is altered in the presence of A beta(1-40.) Our data show that neuroserpin polymerization proceeds first by the unimolecular formation of an active monomer, followed by competing processes of both polymerization and formation of a latent monomer from the activated species. These data are not in keeping with the recently proposed domain swap model of polymer formation in which the latent species and activated monomer are likely to be formed by competing pathways directly from the unactivated monomeric serpin. Moreover, the A beta(1-40) peptide forms a weak complex with neuroserpin (dissociation constant of 10 +/- 5 nM) that increases the amount of active monomer thereby increasing the rate of polymerization. The A beta(1-40) is displaced from the complex so that it acts as a catalyst and is not incorporated into neuroserpin polymers.
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Affiliation(s)
- Albert Chiou
- Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
| | - Peter Hägglöf
- Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Cambridge, United Kingdom
| | - Angel Orte
- Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
| | - Allen Yuyin Chen
- Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
| | - Paul D. Dunne
- Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
| | - Didier Belorgey
- Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Cambridge, United Kingdom
| | - Susanna Karlsson-Li
- Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Cambridge, United Kingdom
| | - David A. Lomas
- Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Cambridge, United Kingdom
| | - David Klenerman
- Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
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30
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Gooptu B, Lomas DA. Conformational pathology of the serpins: themes, variations, and therapeutic strategies. Annu Rev Biochem 2009; 78:147-76. [PMID: 19245336 DOI: 10.1146/annurev.biochem.78.082107.133320] [Citation(s) in RCA: 195] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Point mutations cause members of the serine protease inhibitor (serpin) superfamily to undergo a novel conformational transition, forming ordered polymers. These polymers characterize a group of diseases termed the serpinopathies. The formation of polymers underlies the retention of alpha(1)-antitrypsin within hepatocytes and of neuroserpin within neurons to cause cirrhosis and dementia, respectively. Point mutations of antithrombin, C1 inhibitor, alpha(1)-antichymotrypsin, and heparin cofactor II cause a similar conformational transition, resulting in a plasma deficiency that is associated with thrombosis, angioedema, and emphysema. Polymers of serpins can also form in extracellular tissues where they activate inflammatory cascades. This is best described for the Z variant of alpha(1)-antitrypsin in which the proinflammatory properties of polymers provide an explanation for both progressive emphysema and the selective advantage of this mutant allele. Therapeutic strategies are now being developed to block the aberrant conformational transitions and so treat the serpinopathies.
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Affiliation(s)
- Bibek Gooptu
- School of Crystallography, Birkbeck College, University of London, London, UK.
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31
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α1-Antitrypsin deficiency, chronic obstructive pulmonary disease and the serpinopathies. Clin Sci (Lond) 2009; 116:837-50. [DOI: 10.1042/cs20080484] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
α1-Antitrypsin is the prototypical member of the serine proteinase inhibitor or serpin superfamily of proteins. The family includes α1-antichymotrypsin, C1 inhibitor, antithrombin and neuroserpin, which are all linked by a common molecular structure and the same suicidal mechanism for inhibiting their target enzymes. Point mutations result in an aberrant conformational transition and the formation of polymers that are retained within the cell of synthesis. The intracellular accumulation of polymers of mutant α1-antitrypsin and neuroserpin results in a toxic gain-of-function phenotype associated with cirrhosis and dementia respectively. The lack of important inhibitors results in overactivity of proteolytic cascades and diseases such as COPD (chronic obstructive pulmonary disease) (α1-antitrypsin and α1-antichymotrypsin), thrombosis (antithrombin) and angio-oedema (C1 inhibitor). We have grouped these conditions that share the same underlying disease mechanism together as the serpinopathies. In the present review, the molecular and pathophysiological basis of α1-antitrypsin deficiency and other serpinopathies are considered, and we show how understanding this unusual mechanism of disease has resulted in the development of novel therapeutic strategies.
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Takehara S, Onda M, Zhang J, Nishiyama M, Yang X, Mikami B, Lomas DA. The 2.1-A crystal structure of native neuroserpin reveals unique structural elements that contribute to conformational instability. J Mol Biol 2009; 388:11-20. [PMID: 19285087 DOI: 10.1016/j.jmb.2009.03.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2008] [Revised: 03/03/2009] [Accepted: 03/04/2009] [Indexed: 11/23/2022]
Abstract
Neuroserpin is a selective inhibitor of tissue-type plasminogen activator (tPA) that plays an important role in neuronal plasticity, memory, and learning. We report here the crystal structure of native human neuroserpin at 2.1 A resolution. The structure has a helical reactive center loop and an omega loop between strands 1B and 2B. The omega loop contributes to the inhibition of tPA, as deletion of this motif reduced the association rate constant with tPA by threefold but had no effect on the kinetics of interaction with urokinase. Point mutations in neuroserpin cause the formation of ordered intracellular polymers that underlie dementia familial encephalopathy with neuroserpin inclusion bodies (FENIB). Wild-type neuroserpin is also unstable and readily forms polymers under near-physiological conditions in vitro. This is, in part, due to the substitution of a conserved alanine for serine at position 340. The replacement of Ser340 by Ala increased the melting temperature by 3 degrees C and reduced polymerization as compared to wild-type neuroserpin. Similarly, neuroserpin has Asn-Leu-Val at the end of helix F and thus differs markedly from the Gly-X-Ile consensus sequence of the serpins. Restoration of these amino acids to the consensus sequence increased thermal stability and reduced the polymerization of neuroserpin and its transition to the latent conformer. Moreover, introduction of the consensus sequence into S49P neuroserpin that causes FENIB increased the stability and inhibitory activity of the mutant, as well as blocked polymerization and increased the yield of protein during refolding. These data provide a molecular explanation for the inherent instability of neuroserpin and the effect of point mutations that underlie the dementia FENIB.
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Affiliation(s)
- Sayaka Takehara
- Division of Applied Life Sciences, The Graduate School of Agriculture, Kyoto University, Uji 611-0011, Japan
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33
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Takasawa A, Kato I, Takasawa K, Ishii Y, Yoshida T, Shehata MH, Kawaguchi H, Mohafez OMM, Sasahara M, Hiraga K. Mutation-, aging-, and gene dosage-dependent accumulation of neuroserpin (G392E) in endoplasmic reticula and lysosomes of neurons in transgenic mice. J Biol Chem 2008; 283:35606-13. [PMID: 18940798 DOI: 10.1074/jbc.m804125200] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Mutations in human neuroserpin gene cause an autosomal dementia, familial encephalopathy with neuroserpin inclusion bodies (FENIB). We generated and analyzed transgenic mice expressing high levels of either FENIB-type (G392E) or wild-type human neuroserpin in neurons of the central nervous system. G392E neuroserpin accumulated age-dependently in neurons of the neocortex, thalamus, amygdala, pons, and spinal cord of homozygous transgenic mice. Such accumulations were not observed in hemizygous transgenic mice nor in transgenic mice for wild-type neuroserpin. In differential centrifugation of brain homogenates, G392E neuroserpin recovered in the nucleus-rich fraction dramatically increased along with aging, suggesting that the aggregations gradually increase their densities presumably by their conversion into heavier and more compact configurations. In immunoelectron microscopical analyses, immunopositivities for G392E neuroserpin were found not only in endoplasmic reticulum but also in lysosomes. G392E neuroserpin transgenic mice were much more susceptible to seizures induced by kainate administration than nontransgenic mice. Overall, G392E neuroserpin accumulated in the central nervous system neurons of transgenic mice in mutation-, aging-, and gene dosage-dependent manners. The established transgenic mice will be valuable to elucidate not only mechanisms for the formation of G392E neuroserpin aggregations but also pathways for the degradation and/or clearance of the already formed aggregations in neurons.
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Affiliation(s)
- Akira Takasawa
- Department of Biochemistry, University of Toyama, Graduate School of Medicine and Pharmaceutical Sciences, 2630 Sugitani, Toyama 930-0194, Japan
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Miranda E, MacLeod I, Davies MJ, Pérez J, Römisch K, Crowther DC, Lomas DA. The intracellular accumulation of polymeric neuroserpin explains the severity of the dementia FENIB. Hum Mol Genet 2008; 17:1527-39. [PMID: 18267959 PMCID: PMC2387220 DOI: 10.1093/hmg/ddn041] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2007] [Accepted: 02/07/2008] [Indexed: 11/13/2022] Open
Abstract
Familial encephalopathy with neuroserpin inclusion bodies (FENIB) is an autosomal dominant dementia that is characterized by the retention of polymers of neuroserpin as inclusions within the endoplasmic reticulum (ER) of neurons. We have developed monoclonal antibodies that detect polymerized neuroserpin and have used COS-7 cells, stably transfected PC12 cell lines and transgenic Drosophila melanogaster to characterize the cellular handling of all four mutant forms of neuroserpin that cause FENIB. We show a direct correlation between the severity of the disease-causing mutation and the accumulation of neuroserpin polymers in cell and fly models of the disease. Moreover, mutant neuroserpin causes locomotor deficits in the fly allowing us to demonstrate a direct link between polymer accumulation and neuronal toxicity.
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Affiliation(s)
- Elena Miranda
- Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, UK.
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Onda M, Nakatani K, Takehara S, Nishiyama M, Takahashi N, Hirose M. Cleaved serpin refolds into the relaxed state via a stressed conformer. J Biol Chem 2008; 283:17568-78. [PMID: 18390904 DOI: 10.1074/jbc.m709262200] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Serine proteinase inhibitors (serpins) are believed to fold in vivo into a metastable "stressed" state with cleavage of their P1-P1' bond resulting in reactive center loop insertion and a thermostable "relaxed" state. To understand this unique folding mechanism, we investigated the refolding processes of the P1-P1'-cleaved forms of wild type ovalbumin (cl-OVA) and the R339T mutant (cl-R339T). In the native conditions, cl-OVA is trapped as the stressed conformer, whereas cl-R339T attains the relaxed structure. Under urea denaturing conditions, these cleaved proteins completely dissociated into the heavy (Gly(1)-Ala(352)) and light (Ser(353)-Pro(385)) chains. Upon refolding, the heavy chains of both proteins formed essentially the same initial burst refolding intermediates and then reassociated with the light chain counterparts. The reassociated intermediates both refolded into the native states with indistinguishable kinetics. The two refolded proteins, however, had a notable difference in thermostability. cl-OVA refolded into the stressed form with T(m) = 68.4 degrees C, whereas cl-R339T refolded into the relaxed form with T(m) = 85.5 degrees C. To determine whether cl-R339T refolds directly to the relaxed state or through the stressed state, conformational analyses by anion-exchange chromatography and fluorescence measurements were executed. The results showed that cl-R339T refolds first to the stressed conformation and then undergoes the loop insertion. This is the first demonstration that the P1-P1'-cleaved serpin peptide capable of loop insertion refolds to the stressed conformation. This highlights that the stressed conformation of serpins is an inevitable intermediate state on the folding pathway to the relaxed structure.
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Affiliation(s)
- Maki Onda
- Department of Biological Science, Graduate School of Science, Osaka Prefecture University, Gakuencho 1-2, Nakaku, Sakai 599-8570, Japan.
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Zhang Q, Law RHP, Bottomley SP, Whisstock JC, Buckle AM. A structural basis for loop C-sheet polymerization in serpins. J Mol Biol 2008; 376:1348-59. [PMID: 18234218 DOI: 10.1016/j.jmb.2007.12.050] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2007] [Revised: 12/17/2007] [Accepted: 12/20/2007] [Indexed: 10/22/2022]
Abstract
In this study, we report the X-ray crystal structure of an N-terminally truncated variant of the bacterial serpin, tengpin (tengpinDelta42). Our data reveal that tengpinDelta42 adopts a variation of the latent conformation in which the reactive center loop is hyperinserted into the A beta-sheet and removed from the vicinity of the C-sheet. This conformational change leaves the C beta-sheet completely exposed and permits antiparallel edge-strand interactions between the exposed portion of the reactive center loop of one molecule and strand s2C of the C beta-sheet of the neighboring molecule in the crystal lattice. Our structural data thus reveal that tengpinDelta42 forms a loop C-sheet polymer in the crystal lattice. In vivo serpins have a propensity to misfold and form long-chain polymers, a process that underlies serpinopathies such as emphysema, thrombosis and dementia. Native serpins are thought to polymerize via a loop A-sheet mechanism. However, studies on plasminogen activator inhibitor 1 and the S49P variant of human neuroserpin reveal that the latent form of these molecules can also polymerize. Polymerization of latent neuroserpin may be important for the development of familial encephalopathy with neuroserpin inclusion bodies. Our structural data provide a possible mechanism for polymerization by latent serpins.
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Affiliation(s)
- Qingwei Zhang
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Melbourne, VIC 3800, Australia
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37
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Chen PY, Chang WSW, Chou RH, Lai YK, Lin SC, Chi CY, Wu CW. Two non-homologous brain diseases-related genes, SERPINI1 and PDCD10, are tightly linked by an asymmetric bidirectional promoter in an evolutionarily conserved manner. BMC Mol Biol 2007; 8:2. [PMID: 17212813 PMCID: PMC1796892 DOI: 10.1186/1471-2199-8-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2006] [Accepted: 01/09/2007] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Despite of the fact that mammalian genomes are far more spacious than prokaryotic genomes, recent nucleotide sequencing data have revealed that many mammalian genes are arranged in a head-to-head orientation and separated by a small intergenic sequence. Extensive studies on some of these neighboring genes, in particular homologous gene pairs, have shown that these genes are often co-expressed in a symmetric manner and regulated by a shared promoter region. Here we report the identification of two non-homologous brain disease-related genes, with one coding for a serine protease inhibitor (SERPINI1) and the other for a programmed cell death-related gene (PDCD10), being tightly linked together by an asymmetric bidirectional promoter in an evolutionarily conserved fashion. This asymmetric bidirectional promoter, in cooperation with some cis-acting elements, is responsible for the co-regulation of the gene expression pattern as well as the tissue specificity of SERPINI1 and PDCD10. RESULTS While SERPINI1 is predominantly expressed in normal brain and down-regulated in brain tumors, PDCD10 is ubiquitously expressed in all normal tissues but its gene transcription becomes aberrant in different types of cancers. By measuring the luciferase activity in various cell lysates, their 851-bp intergenic sequence was shown to be capable of driving the reporter gene expression in either direction. A 175-bp fragment from nt 1 to 175 in the vicinity of PDCD10 was further determined to function as a minimal bidirectional promoter. A critical regulatory fragment, from nt 176-473 outside the minimal promoter in the intergenic region, was identified to contain a strong repressive element for SERPINI1 and an enhancer for PDCD10. These cis-acting elements may exist to help coordinate the expression and regulation of the two flanking genes. CONCLUSION For all non-homologous genes that have been described to be closely adjacent in the mammalian genomes, the intergenic region of the head-to-head PDCD10-SERPINI1 gene pair provides an interesting and informative example of a complex regulatory system that governs the expression of both genes not only through an asymmetric bidirectional promoter, but also through fine-tuned regulations with some cis-acting elements.
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Affiliation(s)
- Ping-Yen Chen
- President's Laboratory and Institute of Cancer Research, National Health Research Institutes, Zhunan Town, Miaoli County 350, Taiwan, ROC
- Department of Life Sciences, National Tsing Hua University, Hsinchu City 300, Taiwan, ROC
| | - Wun-Shaing W Chang
- President's Laboratory and Institute of Cancer Research, National Health Research Institutes, Zhunan Town, Miaoli County 350, Taiwan, ROC
| | - Ruey-Hwang Chou
- President's Laboratory and Institute of Cancer Research, National Health Research Institutes, Zhunan Town, Miaoli County 350, Taiwan, ROC
| | - Yiu-Kay Lai
- Department of Life Sciences, National Tsing Hua University, Hsinchu City 300, Taiwan, ROC
- Department of Bioresources, Da-Yeh University, Changhua County 515, Taiwan, ROC
| | - Sheng-Chieh Lin
- President's Laboratory and Institute of Cancer Research, National Health Research Institutes, Zhunan Town, Miaoli County 350, Taiwan, ROC
| | - Chia-Yi Chi
- President's Laboratory and Institute of Cancer Research, National Health Research Institutes, Zhunan Town, Miaoli County 350, Taiwan, ROC
| | - Cheng-Wen Wu
- President's Laboratory and Institute of Cancer Research, National Health Research Institutes, Zhunan Town, Miaoli County 350, Taiwan, ROC
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Belorgey D, Hägglöf P, Karlsson-Li S, Lomas DA. Protein misfolding and the serpinopathies. Prion 2007; 1:15-20. [PMID: 19164889 DOI: 10.4161/pri.1.1.3974] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The serpins are the largest superfamily of protease inhibitors. They are found in almost all branches of life including viruses, prokaryotes and eukaryotes. They inhibit their target protease by a unique mechanism that involves a large conformational transition and the translocation of the enzyme from the upper to the lower pole of the protein. This complex mechanism, and the involvement of serpins in important biological regulatory processes, makes them prone to mutation-related diseases. For example the polymerization of mutant alpha(1)-antitrypsin leads to the accumulation of ordered polymers within the endoplasmic reticulum of hepatocytes in association with cirrhosis. An identical process in the neuron specific serpin, neuroserpin, results in the accumulation of polymers in neurons and the dementia FENIB. In both cases there is a clear correlation between the molecular instability, the rate of polymer formation and the severity of disease. A similar process underlies the hepatic retention and plasma deficiency of antithrombin, C1 inhibitor, alpha(1)-antichymotrypsin and heparin co-factor II. The common mechanism of polymerization has allowed us to group these conditions together as a novel class of disease, the serpinopathies.
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Affiliation(s)
- Didier Belorgey
- Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Cambridge, United Kingdom
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Kinghorn KJ, Crowther DC, Sharp LK, Nerelius C, Davis RL, Chang HT, Green C, Gubb DC, Johansson J, Lomas DA. Neuroserpin binds Abeta and is a neuroprotective component of amyloid plaques in Alzheimer disease. J Biol Chem 2006; 281:29268-77. [PMID: 16849336 DOI: 10.1074/jbc.m600690200] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Alzheimer disease is characterized by extracellular plaques composed of Abeta peptides. We show here that these plaques also contain the serine protease inhibitor neuroserpin and that neuroserpin forms a 1:1 binary complex with the N-terminal or middle parts of the Abeta(1-42) peptide. This complex inactivates neuroserpin as an inhibitor of tissue plasminogen activator and blocks the loop-sheet polymerization process that is characteristic of members of the serpin superfamily. In contrast neuroserpin accelerates the aggregation of Abeta(1-42) with the resulting species having an appearance that is distinct from the mature amyloid fibril. Neuroserpin reduces the cytotoxicity of Abeta(1-42) when assessed using standard cell assays, and the interaction has been confirmed in vivo in novel Drosophila models of disease. Taken together, these data show that neuroserpin interacts with Abeta(1-42) to form off-pathway non-toxic oligomers and so protects neurons in Alzheimer disease.
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Affiliation(s)
- Kerri J Kinghorn
- Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Wellcome Trust/Medical Research Council Building, Hills Road, Cambridge CB2 2XY, United Kingdom
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40
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Robertson AS, Belorgey D, Gubb D, Dafforn TR, Lomas DA. Inhibitory Activity of the Drosophila melanogaster Serpin Necrotic Is Dependent on Lysine Residues in the D-helix. J Biol Chem 2006; 281:26437-43. [PMID: 16835244 DOI: 10.1074/jbc.m606085200] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Necrotic is a member of the serine protease inhibitor or serpin superfamily. It is a potent inhibitor of elastase and chymotrypsin type proteases and is responsible for regulating the anti-fungal response in Drosophila melanogaster. Necrotic contains three basic lysine residues within the D-helix that are homologous to those found in the heparin-binding domain of antithrombin and heparin co-factor II. We show here that substitution of all three lysine residues for glutamines caused cellular necrosis and premature death in Drosophila in keeping with a loss of function phenotype. The lysine to glutamine substitutions had no effect on the overall structure of recombinant Necrotic protein but abolished the formation of stable complexes with target proteases. Individual substitutions with either glutamine or alanine demonstrated that lysine 68 was the most critical residue for inhibitory activity. Despite the homology to other serpins, Necrotic did not bind, nor was it activated by sulfated glycans. These data demonstrate a critical role for basic residues within the D-helix (and lysine 68 in particular) in the inhibitory mechanism of the serpin Necrotic.
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Affiliation(s)
- Andrew S Robertson
- Department of Genetics, University of Cambridge, Cambridge CB2 3EH, United Kingdom
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41
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Sharp LK, Mallya M, Kinghorn KJ, Wang Z, Crowther DC, Huntington JA, Belorgey D, Lomas DA. Sugar and alcohol molecules provide a therapeutic strategy for the serpinopathies that cause dementia and cirrhosis. FEBS J 2006; 273:2540-52. [PMID: 16704419 DOI: 10.1111/j.1742-4658.2006.05262.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Mutations in neuroserpin and alpha1-antitrypsin cause these proteins to form ordered polymers that are retained within the endoplasmic reticulum of neurones and hepatocytes, respectively. The resulting inclusions underlie the dementia familial encephalopathy with neuroserpin inclusion bodies (FENIB) and Z alpha1-antitrypsin-associated cirrhosis. Polymers form by a sequential linkage between the reactive centre loop of one molecule and beta-sheet A of another, and strategies that block polymer formation are likely to be successful in treating the associated disease. We show here that glycerol, the sugar alcohol erythritol, the disaccharide trehalose and its breakdown product glucose reduce the rate of polymerization of wild-type neuroserpin and the Ser49Pro mutant that causes dementia. They also attenuate the polymerization of the Z variant of alpha1-antitrypsin. The effect on polymerization was apparent even when these agents had been removed from the buffer. None of these agents had any detectable effect on the structure or inhibitory activity of neuroserpin or alpha1-antitrypsin. These data demonstrate that sugar and alcohol molecules can reduce the polymerization of serpin mutants that cause disease, possibly by binding to and stabilizing beta-sheet A.
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42
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Carrell RW. Cell toxicity and conformational disease. Trends Cell Biol 2005; 15:574-80. [PMID: 16202603 DOI: 10.1016/j.tcb.2005.09.005] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2005] [Revised: 08/10/2005] [Accepted: 09/20/2005] [Indexed: 11/19/2022]
Abstract
Numerous disorders, including Alzheimer's, Parkinson's and other late-onset neurodegenerative diseases, arise from the conformationally driven aggregation of individual proteins. Previous focus on just one end-product of such aggregation - extracellular deposits of amyloid - has diverted attention from what is now recognized as being primarily intracellular disease processes. Recent structural findings show how cytotoxicity can result from even minor changes in conformation that do not lead to amyloid formation, as with the accumulation within the endoplasmic reticulum of intact mutant alpha-1-antitrypsin in hepatocytes and of neuroserpin in neurons. Studies in Alzheimer's and other dementias also indicate that the damage occurs at the stage of the initial intermolecular linkages that precede amyloid formation. The challenge now is to determine the detailed mechanisms of this cytotoxicity.
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Affiliation(s)
- Robin W Carrell
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK CB2 2XY.
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