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Abstract
Proteins destined for secretion - after removal of the signal sequence - often undergo further proteolytic processing by proprotein convertases (PCs). Prohormones are typically processed in the regulated secretory pathway, while most plasma proteins travel though the constitutive pathway. The complement system is a major proteolytic cascade in the blood, serving as a first line of defense against microbes and also contributing to the immune homeostasis. Several complement components, namely C3, C4, C5 and factor I (FI), are multi-chain proteins that are apparently processed by PCs intracellularly. Cleavage occurs at consecutive basic residues and probably also involves the action of carboxypeptidases. The most likely candidate for the intracellular processing of complement proteins is furin, however, because of the overlapping specificities of basic amino acid residue-specific proprotein convertases, other PCs might be involved. To our surprise, we have recently discovered that processing of another complement protein, mannan-binding lectin-associated serine protease-3 (MASP-3) occurs in the blood by PCSK6 (PACE4). A similar mechanism had been described for the membrane protease corin, which is also activated extracellularly by PCSK6. In this review we intend to point out that the proper functioning of the complement system intimately depends on the action of proprotein convertases. In addition to the non-enzymatic components (C3, C4, C5), two constitutively active complement proteases are directly activated by PCs either intracellularly (FI), or extracellularly (MASP-3), moreover indirectly, through the constitutive activation of pro-factor D by MASP-3, the activity of the alternative pathway also depends on a PC present in the blood.
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Affiliation(s)
| | | | | | - Péter Gál
- *Correspondence: József Dobó, ; Péter Gál,
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2
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Horn N, Wittung-Stafshede P. ATP7A-Regulated Enzyme Metalation and Trafficking in the Menkes Disease Puzzle. Biomedicines 2021; 9:391. [PMID: 33917579 DOI: 10.3390/biomedicines9040391] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Revised: 04/01/2021] [Accepted: 04/02/2021] [Indexed: 12/12/2022] Open
Abstract
Copper is vital for numerous cellular functions affecting all tissues and organ systems in the body. The copper pump, ATP7A is critical for whole-body, cellular, and subcellular copper homeostasis, and dysfunction due to genetic defects results in Menkes disease. ATP7A dysfunction leads to copper deficiency in nervous tissue, liver, and blood but accumulation in other tissues. Site-specific cellular deficiencies of copper lead to loss of function of copper-dependent enzymes in all tissues, and the range of Menkes disease pathologies observed can now be explained in full by lack of specific copper enzymes. New pathways involving copper activated lysosomal and steroid sulfatases link patient symptoms usually related to other inborn errors of metabolism to Menkes disease. Additionally, new roles for lysyl oxidase in activation of molecules necessary for the innate immune system, and novel adapter molecules that play roles in ERGIC trafficking of brain receptors and other proteins, are emerging. We here summarize the current knowledge of the roles of copper enzyme function in Menkes disease, with a focus on ATP7A-mediated enzyme metalation in the secretory pathway. By establishing mechanistic relationships between copper-dependent cellular processes and Menkes disease symptoms in patients will not only increase understanding of copper biology but will also allow for the identification of an expanding range of copper-dependent enzymes and pathways. This will raise awareness of rare patient symptoms, and thus aid in early diagnosis of Menkes disease patients.
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3
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Goicoechea de Jorge E, López Lera A, Bayarri-Olmos R, Yebenes H, Lopez-Trascasa M, Rodríguez de Córdoba S. Common and rare genetic variants of complement components in human disease. Mol Immunol 2018; 102:42-57. [PMID: 29914697 DOI: 10.1016/j.molimm.2018.06.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 06/06/2018] [Accepted: 06/08/2018] [Indexed: 12/21/2022]
Abstract
Genetic variability in the complement system and its association with disease has been known for more than 50 years, but only during the last decade have we begun to understand how this complement genetic variability contributes to the development of diseases. A number of reports have described important genotype-phenotype correlations that associate particular diseases with genetic variants altering specific aspects of the activation and regulation of the complement system. The detailed functional characterization of some of these genetic variants provided key insights into the pathogenic mechanisms underlying these pathologies, which is facilitating the design of specific anti-complement therapies. Importantly, these analyses have sometimes revealed unknown features of the complement proteins. As a whole, these advances have delineated the functional implications of genetic variability in the complement system, which supports the implementation of a precision medicine approach based on the complement genetic makeup of the patients. Here we provide an overview of rare complement variants and common polymorphisms associated with disease and discuss what we have learned from them.
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Affiliation(s)
- Elena Goicoechea de Jorge
- Department of Immunology, Complutense University, Madrid, Spain; Research Institute Hospital 12 de Octubre (imas12), Madrid, Spain
| | - Alberto López Lera
- Research Institute Hospital Universitario La Paz (IdiPaz), Madrid, Spain; Ciber de Enfermedades Raras, Madrid, Spain
| | - Rafael Bayarri-Olmos
- Department of Clinical Immunology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Hugo Yebenes
- Ciber de Enfermedades Raras, Madrid, Spain; Molecular Pathology and Complement Genetics Unit. Centro de Investigaciones Biológicas, CSIC, Madrid, Spain
| | | | - Santiago Rodríguez de Córdoba
- Ciber de Enfermedades Raras, Madrid, Spain; Molecular Pathology and Complement Genetics Unit. Centro de Investigaciones Biológicas, CSIC, Madrid, Spain.
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4
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Oroszlán G, Dani R, Szilágyi A, Závodszky P, Thiel S, Gál P, Dobó J. Extensive Basal Level Activation of Complement Mannose-Binding Lectin-Associated Serine Protease-3: Kinetic Modeling of Lectin Pathway Activation Provides Possible Mechanism. Front Immunol 2017; 8:1821. [PMID: 29326707 PMCID: PMC5741598 DOI: 10.3389/fimmu.2017.01821] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 12/04/2017] [Indexed: 12/01/2022] Open
Abstract
Serine proteases (SPs) are typically synthesized as precursors, termed proenzymes or zymogens, and the fully active form is produced via limited proteolysis by another protease or by autoactivation. The lectin pathway of the complement system is initiated by mannose-binding lectin (MBL)-associated SPs (MASP)-1, and MASP-2, which are known to be present as proenzymes in blood. The third SP of the lectin pathway, MASP-3, was recently shown to be the major activator, and the exclusive “resting blood” activator of profactor D, producing factor D, the initiator protease of the alternative pathway. Because only activated MASP-3 is capable of carrying out this cleavage, it was presumed that a significant fraction of MASP-3 must be present in the active form in resting blood. Here, we aimed to detect active MASP-3 in the blood by a more direct technique and to quantitate the active to zymogen ratio. First, MASPs were partially purified (enriched) from human plasma samples by affinity chromatography using immobilized MBL in the presence of inhibitors. Using this MASP pool, only the zymogen form of MASP-1 was detected by Western blot, whereas over 70% MASP-3 was in an activated form in the same samples. Furthermore, the active to zymogen ratio of MASP-3 showed little individual variation. It is enigmatic how MASP-3, which is not able to autoactivate, is present mostly as an active enzyme, whereas MASP-1, which has a potent autoactivation capability, is predominantly proenzymic in resting blood. In an attempt to explain this phenomenon, we modeled the basal level fluid-phase activation of lectin pathway proteases and their subsequent inactivation by C1 inhibitor and antithrombin using available and newly determined kinetic constants. The model can explain extensive MASP-3 activation only if we assume efficient intracomplex activation of MASP-3 by zymogen MASP-1. On the other hand, the model is in good agreement with the fact that MASP-1 and -2 are predominantly proenzymic and some of them is present in the form of inactive serpin–protease complexes. As an alternative hypothesis, MASP-3 activation by proprotein convertases is also discussed.
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Affiliation(s)
- Gábor Oroszlán
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Ráhel Dani
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - András Szilágyi
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Péter Závodszky
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Steffen Thiel
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Péter Gál
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - József Dobó
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
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5
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Affiliation(s)
- Abishek Iyer
- Centre for Inflammation and Disease Research, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
- ARC Centre of Excellence in Advanced Molecular Imaging, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Weijun Xu
- ARC Centre of Excellence in Advanced Molecular Imaging, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Robert C. Reid
- ARC Centre of Excellence in Advanced Molecular Imaging, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - David P. Fairlie
- Centre for Inflammation and Disease Research, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
- ARC Centre of Excellence in Advanced Molecular Imaging, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
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Pihl R, Jensen L, Hansen AG, Thøgersen IB, Andres S, Dagnæs-Hansen F, Oexle K, Enghild JJ, Thiel S. Analysis of Factor D Isoforms in Malpuech-Michels-Mingarelli-Carnevale Patients Highlights the Role of MASP-3 as a Maturase in the Alternative Pathway of Complement. J Immunol 2017; 199:ji1700518. [PMID: 28794230 DOI: 10.4049/jimmunol.1700518] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 07/10/2017] [Indexed: 11/19/2022]
Abstract
Factor D (FD), which is also known as adipsin, is regarded as the first-acting protease of the alternative pathway (AP) of complement. It has been suggested that FD is secreted as a mature enzyme that does not require subsequent activation. This view was challenged when it was shown that mice lacking mannose-binding lectin (MBL)-associated serine protease-1 (MASP-1) and MASP-3 contain zymogenic FD (pro-FD), and it is becoming evident that MASP-3 is implicated in pro-FD maturation. However, the necessity of MASP-3 for pro-FD cleavage has been questioned, because AP activity is still observed in sera from MASP-1/3-deficient Malpuech-Michels-Mingarelli-Carnevale (3MC) patients. The identification of a novel 3MC patient carrying a previously unidentified MASP-3 G665S mutation prompted us to develop an analytical isoelectric focusing technique that resolves endogenous FD variants in complex samples. This enabled us to show that although 3MC patients predominantly contain pro-FD, they also contain detectable levels of mature FD. Moreover, using isoelectric focusing analysis, we show that both pro-FD and FD are present in the circulation of healthy donors. We characterized the naturally occurring 3MC-associated MASP-3 mutants and found that they all yielded enzymatically inactive proteins. Using MASP-3-depleted human serum, serum from 3MC patients, and Masp1/3-/- mice, we found that lack of enzymatically active MASP-3, or complete MASP-3 deficiency, compromises the conversion of pro-FD to FD. In summary, our observations emphasize that MASP-3 acts as an important maturase in the AP of complement, while also highlighting that there exists MASP-3-independent pro-FD maturation in 3MC patients.
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Affiliation(s)
- Rasmus Pihl
- Department of Biomedicine, Aarhus University, DK-8000 Aarhus, Denmark;
| | - Lisbeth Jensen
- Department of Biomedicine, Aarhus University, DK-8000 Aarhus, Denmark
| | - Annette G Hansen
- Department of Biomedicine, Aarhus University, DK-8000 Aarhus, Denmark
| | - Ida B Thøgersen
- Department of Molecular Biology and Genetics, Aarhus University, DK-8000 Aarhus, Denmark
| | - Stephanie Andres
- Institute of Human Genetics, Technical University Munich, D-81675 München, Germany; and
| | | | - Konrad Oexle
- Institute of Neurogenomics, Helmholtz Zentrum Munich, D-85764 Neuherberg, Germany
| | - Jan J Enghild
- Department of Molecular Biology and Genetics, Aarhus University, DK-8000 Aarhus, Denmark
| | - Steffen Thiel
- Department of Biomedicine, Aarhus University, DK-8000 Aarhus, Denmark
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Mizuno M, Suzuki Y, Ito Y. Complement regulation and kidney diseases: recent knowledge of the double-edged roles of complement activation in nephrology. Clin Exp Nephrol 2017; 22:3-14. [DOI: 10.1007/s10157-017-1405-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 03/14/2017] [Indexed: 12/28/2022]
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8
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Mortensen SA, Skov LL, Kjaer-Sorensen K, Hansen AG, Hansen S, Dagnæs-Hansen F, Jensenius JC, Oxvig C, Thiel S, Degn SE. Endogenous Natural Complement Inhibitor Regulates Cardiac Development. J Immunol 2017; 198:3118-3126. [PMID: 28258200 DOI: 10.4049/jimmunol.1601958] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 02/09/2017] [Indexed: 01/26/2023]
Abstract
Congenital heart defects are a major cause of perinatal mortality and morbidity, affecting >1% of all live births in the Western world, yet a large fraction of such defects have an unknown etiology. Recent studies demonstrated surprising dual roles for immune-related molecules and their effector mechanisms during fetal development and adult homeostasis. In this article, we describe the function of an endogenous complement inhibitor, mannan-binding lectin (MBL)-associated protein (MAp)44, in regulating the composition of a serine protease-pattern recognition receptor complex, MBL-associated serine protease (MASP)-3/collectin-L1/K1 hetero-oligomer, which impacts cardiac neural crest cell migration. We used knockdown and rescue strategies in zebrafish, a model allowing visualization and assessment of heart function, even in the presence of severe functional defects. Knockdown of embryonic expression of MAp44 caused impaired cardiogenesis, lowered heart rate, and decreased cardiac output. These defects were associated with aberrant neural crest cell behavior. We found that MAp44 competed with MASP-3 for pattern recognition molecule interaction, and knockdown of endogenous MAp44 expression could be rescued by overexpression of wild-type MAp44. Our observations provide evidence that immune molecules are centrally involved in the orchestration of cardiac tissue development.
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Affiliation(s)
- Simon A Mortensen
- Department of Biomedicine, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Louise L Skov
- Department of Molecular Biology and Genetics, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Kasper Kjaer-Sorensen
- Department of Molecular Biology and Genetics, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Annette G Hansen
- Department of Biomedicine, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Søren Hansen
- Department of Cancer and Inflammation Research, University of Southern Denmark, DK-5000 Odense, Denmark; and
| | | | - Jens C Jensenius
- Department of Biomedicine, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Claus Oxvig
- Department of Molecular Biology and Genetics, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Steffen Thiel
- Department of Biomedicine, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Søren E Degn
- Department of Biomedicine, Aarhus University, DK-8000 Aarhus C, Denmark; .,Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA 02115
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9
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Wang X, Gao B, Zhu S. Exon Shuffling and Origin of Scorpion Venom Biodiversity. Toxins (Basel) 2016; 9:toxins9010010. [PMID: 28035955 PMCID: PMC5308243 DOI: 10.3390/toxins9010010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 12/13/2016] [Accepted: 12/21/2016] [Indexed: 12/01/2022] Open
Abstract
Scorpion venom is a complex combinatorial library of peptides and proteins with multiple biological functions. A combination of transcriptomic and proteomic techniques has revealed its enormous molecular diversity, as identified by the presence of a large number of ion channel-targeted neurotoxins with different folds, membrane-active antimicrobial peptides, proteases, and protease inhibitors. Although the biodiversity of scorpion venom has long been known, how it arises remains unsolved. In this work, we analyzed the exon-intron structures of an array of scorpion venom protein-encoding genes and unexpectedly found that nearly all of these genes possess a phase-1 intron (one intron located between the first and second nucleotides of a codon) near the cleavage site of a signal sequence despite their mature peptides remarkably differ. This observation matches a theory of exon shuffling in the origin of new genes and suggests that recruitment of different folds into scorpion venom might be achieved via shuffling between body protein-coding genes and ancestral venom gland-specific genes that presumably contributed tissue-specific regulatory elements and secretory signal sequences.
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Affiliation(s)
- Xueli Wang
- Group of Peptide Biology and Evolution, State Key Laboratory of Integrated Management of Pest Insects & Rodents, Institute of Zoology, Chinese Academy of Sciences, 1 Beichen West Road, Chaoyang District, Beijing 100101, China.
| | - Bin Gao
- Group of Peptide Biology and Evolution, State Key Laboratory of Integrated Management of Pest Insects & Rodents, Institute of Zoology, Chinese Academy of Sciences, 1 Beichen West Road, Chaoyang District, Beijing 100101, China.
| | - Shunyi Zhu
- Group of Peptide Biology and Evolution, State Key Laboratory of Integrated Management of Pest Insects & Rodents, Institute of Zoology, Chinese Academy of Sciences, 1 Beichen West Road, Chaoyang District, Beijing 100101, China.
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10
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Abstract
Mannose-binding lectin (MBL), collectin-10, collectin-11, and the ficolins (ficolin-1, ficolin-2, and ficolin-3) are soluble pattern recognition molecules in the lectin complement pathway. These proteins act as mediators of host defense and participate in maintenance of tissue homeostasis. They bind to conserved pathogen-specific structures and altered self-antigens and form complexes with the pentraxins to modulate innate immune functions. All molecules exhibit distinct expression in different tissue compartments, but all are found to a varying degree in the circulation. A common feature of these molecules is their ability to interact with a set of serine proteases named MASPs (MASP-1, MASP-2, and MASP-3). MASP-1 and -2 trigger the activation of the lectin pathway and MASP-3 may be involved in the activation of the alternative pathway of complement. Furthermore, MASPs mediate processes related to coagulation, bradykinin release, and endothelial and platelet activation. Variant alleles affecting expression and structure of the proteins have been associated with a variety of infectious and non-infectious diseases, most commonly as disease modifiers. Notably, the severe 3MC (Malpuech, Michels, Mingarelli, and Carnevale) embryonic development syndrome originates from rare mutations affecting either collectin-11 or MASP-3, indicating a broader functionality of the complement system than previously anticipated. This review summarizes the characteristics of the molecules in the lectin pathway.
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Affiliation(s)
- Peter Garred
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
| | - Ninette Genster
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Katrine Pilely
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Rafael Bayarri-Olmos
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Anne Rosbjerg
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Ying Jie Ma
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mikkel-Ole Skjoedt
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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11
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Dobó J, Szakács D, Oroszlán G, Kortvely E, Kiss B, Boros E, Szász R, Závodszky P, Gál P, Pál G. MASP-3 is the exclusive pro-factor D activator in resting blood: the lectin and the alternative complement pathways are fundamentally linked. Sci Rep 2016; 6:31877. [PMID: 27535802 DOI: 10.1038/srep31877] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 07/29/2016] [Indexed: 11/08/2022] Open
Abstract
MASP-3 was discovered 15 years ago as the third mannan-binding lectin (MBL)-associated serine protease of the complement lectin pathway. Lacking any verified substrate its role remained ambiguous. MASP-3 was shown to compete with a key lectin pathway enzyme MASP-2 for MBL binding, and was therefore considered to be a negative complement regulator. Later, knock-out mice experiments suggested that MASP-1 and/or MASP-3 play important roles in complement pro-factor D (pro-FD) maturation. However, studies on a MASP-1/MASP-3-deficient human patient produced contradicting results. In normal resting blood unperturbed by ongoing coagulation or complement activation, factor D is present predominantly in its active form, suggesting that resting blood contains at least one pro-FD activating proteinase that is not a direct initiator of coagulation or complement activation. We have recently showed that all three MASPs can activate pro-FD in vitro. In resting blood, however, using our previously evolved MASP-1 and MASP-2 inhibitors we proved that neither MASP-1 nor MASP-2 activates pro-FD. Other plasma proteinases, particularly MASP-3, remained candidates for that function. For this study we evolved a specific MASP-3 inhibitor and unambiguously proved that activated MASP-3 is the exclusive pro-FD activator in resting blood, which demonstrates a fundamental link between the lectin and alternative pathways.
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12
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Urquhart J, Roberts R, de Silva D, Shalev S, Chervinsky E, Nampoothiri S, Sznajer Y, Revencu N, Gunasekera R, Suri M, Ellingford J, Williams S, Bhaskar S, Clayton-Smith J. Exploring the genetic basis of 3MC syndrome: Findings in 12 further families. Am J Med Genet A 2016; 170A:1216-24. [DOI: 10.1002/ajmg.a.37564] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 12/22/2015] [Indexed: 12/18/2022]
Affiliation(s)
- Jill Urquhart
- Faculty of Medical and Human Sciences, Institute of Human Development, Manchester Centre for Genomic Medicine, University of Manchester; Manchester Academic Health Science Centre (MAHSC); Manchester United Kingdom
- Manchester Centre for Genomic Medicine, Central Manchester University Hospitals NHS Foundation Trust; MAHSC; Manchester United Kingdom
| | - Rebecca Roberts
- Manchester Medical School; University of Manchester; Manchester United Kingdom
| | - Deepthi de Silva
- Faculty of Medicine, Department of Physiology; University of Kelaniya; Ragama Sri Lanka
| | - Stavit Shalev
- Genetic Institute; Ha'Emek Medical Center; Afula Israel
| | | | | | - Yves Sznajer
- Cliniques Universitaires Saint-Luc; Centre for Human Genetics; Brussels Belgium
| | - Nicole Revencu
- Cliniques Universitaires Saint-Luc; Centre for Human Genetics; Brussels Belgium
| | - Romesh Gunasekera
- Department of Plastic Surgery; Lady Ridgeway Hospital; Colombo Sri Lanka
| | - Mohnish Suri
- Nottingham Clinical Genetics Service, Nottingham University Hospitals NHS Trust; City Hospital Campus; Nottingham United Kingdom
| | - Jamie Ellingford
- Faculty of Medical and Human Sciences, Institute of Human Development, Manchester Centre for Genomic Medicine, University of Manchester; Manchester Academic Health Science Centre (MAHSC); Manchester United Kingdom
- Manchester Centre for Genomic Medicine, Central Manchester University Hospitals NHS Foundation Trust; MAHSC; Manchester United Kingdom
| | - Simon Williams
- Manchester Centre for Genomic Medicine, Central Manchester University Hospitals NHS Foundation Trust; MAHSC; Manchester United Kingdom
| | - Sanjeev Bhaskar
- Manchester Centre for Genomic Medicine, Central Manchester University Hospitals NHS Foundation Trust; MAHSC; Manchester United Kingdom
| | - Jill Clayton-Smith
- Manchester Centre for Genomic Medicine, Central Manchester University Hospitals NHS Foundation Trust; MAHSC; Manchester United Kingdom
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13
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Bajic G, Degn SE, Thiel S, Andersen GR. Complement activation, regulation, and molecular basis for complement-related diseases. EMBO J 2015; 34:2735-57. [PMID: 26489954 DOI: 10.15252/embj.201591881] [Citation(s) in RCA: 240] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Accepted: 09/28/2015] [Indexed: 01/13/2023] Open
Abstract
The complement system is an essential element of the innate immune response that becomes activated upon recognition of molecular patterns associated with microorganisms, abnormal host cells, and modified molecules in the extracellular environment. The resulting proteolytic cascade tags the complement activator for elimination and elicits a pro-inflammatory response leading to recruitment and activation of immune cells from both the innate and adaptive branches of the immune system. Through these activities, complement functions in the first line of defense against pathogens but also contributes significantly to the maintenance of homeostasis and prevention of autoimmunity. Activation of complement and the subsequent biological responses occur primarily in the extracellular environment. However, recent studies have demonstrated autocrine signaling by complement activation in intracellular vesicles, while the presence of a cytoplasmic receptor serves to detect complement-opsonized intracellular pathogens. Furthermore, breakthroughs in both functional and structural studies now make it possible to describe many of the intricate molecular mechanisms underlying complement activation and the subsequent downstream events, as well as its cross talk with, for example, signaling pathways, the coagulation system, and adaptive immunity. We present an integrated and updated view of complement based on structural and functional data and describe the new roles attributed to complement. Finally, we discuss how the structural and mechanistic understanding of the complement system rationalizes the genetic defects conferring uncontrolled activation or other undesirable effects of complement.
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Affiliation(s)
- Goran Bajic
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Søren E Degn
- Department of Biomedicine, Aarhus University, Aarhus, Denmark Program in Cellular and Molecular Medicine, Children's Hospital, Boston, MA, USA
| | - Steffen Thiel
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Gregers R Andersen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
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Kjaer TR, Le LTM, Pedersen JS, Sander B, Golas MM, Jensenius JC, Andersen GR, Thiel S. Structural insights into the initiating complex of the lectin pathway of complement activation. Structure 2015; 23:342-51. [PMID: 25579818 DOI: 10.1016/j.str.2014.10.024] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Revised: 10/18/2014] [Accepted: 10/21/2014] [Indexed: 10/24/2022]
Abstract
The proteolytic cascade of the complement system is initiated when pattern-recognition molecules (PRMs) bind to ligands, resulting in the activation of associated proteases. In the lectin pathway of complement, the complex of mannan-binding lectin (MBL) and MBL-associated serine protease-1 (MASP-1) initiates the pathway by activating a second protease, MASP-2. Here we present a structural study of a PRM/MASP complex and derive the overall architecture of the 450 kDa MBL/MASP-1 complex using small-angle X-ray scattering and electron microscopy. The serine protease (SP) domains from the zymogen MASP-1 dimer protrude from the cone-like MBL tetramer and are separated by at least 20 nm. This suggests that intracomplex activation within a single MASP-1 dimer is unlikely and instead supports intercomplex activation, whereby the MASP SP domains are accessible to nearby PRM-bound MASPs. This activation mechanism differs fundamentally from the intracomplex initiation models previously proposed for both the lectin and the classical pathway.
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Affiliation(s)
- Troels R Kjaer
- Department of Biomedicine, Aarhus University, Bartholins Allé 6 and Wilhelm Meyers Allé 3, 8000 Aarhus, Denmark
| | - Le T M Le
- Department of Clinical Medicine, Aarhus University, Wilhelm Meyers Allé 3, 8000 Aarhus, Denmark
| | - Jan Skov Pedersen
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus, Denmark; Department of Chemistry, Aarhus University, Langelandsgade 140, 8000 Aarhus, Denmark
| | - Bjoern Sander
- Department of Clinical Medicine, Aarhus University, Wilhelm Meyers Allé 3, 8000 Aarhus, Denmark; Center for Stochastic Geometry and Advanced Bioimaging (CSGB), Aarhus University, Wilhelm Meyers Allé 3, 8000 Aarhus, Denmark
| | - Monika M Golas
- Department of Biomedicine, Aarhus University, Bartholins Allé 6 and Wilhelm Meyers Allé 3, 8000 Aarhus, Denmark; Center for Stochastic Geometry and Advanced Bioimaging (CSGB), Aarhus University, Wilhelm Meyers Allé 3, 8000 Aarhus, Denmark
| | - Jens Christian Jensenius
- Department of Biomedicine, Aarhus University, Bartholins Allé 6 and Wilhelm Meyers Allé 3, 8000 Aarhus, Denmark
| | - Gregers R Andersen
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, 8000 Aarhus, Denmark
| | - Steffen Thiel
- Department of Biomedicine, Aarhus University, Bartholins Allé 6 and Wilhelm Meyers Allé 3, 8000 Aarhus, Denmark.
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Wijeyewickrema LC, Duncan RC, Pike RN. The Role of the Lys628 (192) Residue of the Complement Protease, C1s, in Interacting with Peptide and Protein Substrates. Front Immunol 2014; 5:444. [PMID: 25278939 PMCID: PMC4166353 DOI: 10.3389/fimmu.2014.00444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Accepted: 09/01/2014] [Indexed: 11/25/2022] Open
Abstract
The C1s protease of the classical complement pathway propagates the initial activation of this pathway of the system by cleaving and thereby activating the C4 and C2 complement components. This facilitates the formation of the classical pathway C3 convertase (C4bC2a). C1s has a Lys residue located at position 628 (192 in chymotrypsin numbering) of the SP domain that has the potential to partially occlude the S2–S2′ positions of the active site. The 192 residue of serine proteases generally plays an important role in interactions with substrates. We therefore investigated the role of Lys628 (192) in interactions with C4 by altering the Lys residue to either a Gln (found in many other serine proteases) or an Ala residue. The mutant enzymes had altered specificity profiles for a combinatorial peptide substrate library, suggesting that this residue does influence the active site specificity of the protease. Generally, the K628Q mutant had greater activity than wild type enzyme against peptide substrates, while the K628A residue had lowered activity, although this was not always the case. Against peptide substrates containing physiological substrate sequences, the K628Q mutant once again had generally higher activity, but the activity of the wild type and mutant enzymes against a C4 P4–P4′ substrate were similar. Interestingly, alteration of the K628 residue in C1s had a marked effect on the cleavage of C4, reducing cleavage efficiency for both mutants about fivefold. This indicates that this residue plays a different role in cleaving protein versus peptide substrates and that the Lys residue found in the wild type enzyme plays an important role in interacting with the C4 substrate. Understanding the basis of the interaction between C1s and its physiological substrates is likely to lead to insights that can be used to design efficient inhibitors of the enzyme for use in treating diseases caused by inflammation as result of over-activity of the classical complement pathway.
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Affiliation(s)
| | - Renee Charlene Duncan
- Department of Biochemistry and Molecular Biology, Monash University, Melbourne, VIC, Australia
| | - Robert Neil Pike
- Department of Biochemistry and Molecular Biology, Monash University, Melbourne, VIC, Australia
- *Correspondence: Robert Neil Pike, Department of Biochemistry and Molecular Biology, Monash University, Clayton, Melbourne, VIC 3800, Australia e-mail:
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16
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Dobó J, Schroeder V, Jenny L, Cervenak L, Závodszky P, Gál P. Multiple roles of complement MASP-1 at the interface of innate immune response and coagulation. Mol Immunol 2014; 61:69-78. [PMID: 24935208 DOI: 10.1016/j.molimm.2014.05.013] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Revised: 05/26/2014] [Accepted: 05/27/2014] [Indexed: 11/24/2022]
Abstract
MASP-1 is a versatile serine protease that cleaves a number of substrates in human blood. In recent years it became evident that besides playing a crucial role in complement activation MASP-1 also triggers other cascade systems and even cells to mount a more powerful innate immune response. In this review we summarize the latest discoveries about the diverse functions of this multi-faceted protease. Recent studies revealed that among MBL-associated serine proteases, MASP-1 is the one responsible for triggering the lectin pathway via its ability to rapidly autoactivate then cleave MASP-2, and possibly MASP-3. The crystal structure of MASP-1 explains its more relaxed substrate specificity compared to the related complement enzymes. Due to the relaxed specificity, MASP-1 interacts with the coagulation cascade and the kinin generating system, and it can also activate endothelial cells eliciting pro-inflammatory signaling.
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Affiliation(s)
- József Dobó
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok krt. 2, H-1113 Budapest, Hungary
| | - Verena Schroeder
- Department of Clinical Research, University of Bern, and University Clinic of Haematology, University Hospital, Bern, Switzerland
| | - Lorenz Jenny
- Department of Clinical Research, University of Bern, and University Clinic of Haematology, University Hospital, Bern, Switzerland
| | - László Cervenak
- 3rd Department of Internal Medicine, Semmelweis University, Kútvölgyi út 4, H-1125 Budapest, Hungary
| | - Péter Závodszky
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok krt. 2, H-1113 Budapest, Hungary
| | - Péter Gál
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok krt. 2, H-1113 Budapest, Hungary.
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Beltrame MH, Catarino SJ, Goeldner I, Boldt ABW, de Messias-Reason IJ. The lectin pathway of complement and rheumatic heart disease. Front Pediatr 2014; 2:148. [PMID: 25654073 PMCID: PMC4300866 DOI: 10.3389/fped.2014.00148] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 12/29/2014] [Indexed: 12/19/2022] Open
Abstract
The innate immune system is the first line of host defense against infection and is comprised of humoral and cellular mechanisms that recognize potential pathogens within minutes or hours of entry. The effector components of innate immunity include epithelial barriers, phagocytes, and natural killer cells, as well as cytokines and the complement system. Complement plays an important role in the immediate response against microorganisms, including Streptococcus sp. The lectin pathway is one of three pathways by which the complement system can be activated. This pathway is initiated by the binding of mannose-binding lectin (MBL), collectin 11 (CL-K1), and ficolins (Ficolin-1, Ficolin-2, and Ficolin-3) to microbial surface oligosaccharides and acetylated residues, respectively. Upon binding to target molecules, MBL, CL-K1, and ficolins form complexes with MBL-associated serine proteases 1 and 2 (MASP-1 and MASP-2), which cleave C4 and C2 forming the C3 convertase (C4b2a). Subsequent activation of complement cascade leads to opsonization, phagocytosis, and lysis of target microorganisms through the formation of the membrane-attack complex. In addition, activation of complement may induce several inflammatory effects, such as expression of adhesion molecules, chemotaxis and activation of leukocytes, release of reactive oxygen species, and secretion of cytokines and chemokines. In this chapter, we review the general aspects of the structure, function, and genetic polymorphism of lectin-pathway components and discuss most recent understanding on the role of the lectin pathway in the predisposition and clinical progression of Rheumatic Fever.
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Affiliation(s)
- Marcia Holsbach Beltrame
- Department of Clinical Pathology, Hospital de Clínicas, Universidade Federal do Paraná , Curitiba , Brazil
| | - Sandra Jeremias Catarino
- Department of Clinical Pathology, Hospital de Clínicas, Universidade Federal do Paraná , Curitiba , Brazil
| | - Isabela Goeldner
- Department of Clinical Pathology, Hospital de Clínicas, Universidade Federal do Paraná , Curitiba , Brazil
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Pike RN, Wijeyewickrema LC. The molecular switches controlling the interaction between complement proteases of the classical and lectin pathways and their substrates. Curr Opin Struct Biol 2013; 23:820-7. [DOI: 10.1016/j.sbi.2013.07.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Accepted: 07/24/2013] [Indexed: 11/29/2022]
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