1
|
Yao Z, Fan Y, Lin L, Kellems RE, Xia Y. Tissue transglutaminase: a multifunctional and multisite regulator in health and disease. Physiol Rev 2024; 104:281-325. [PMID: 37712623 DOI: 10.1152/physrev.00003.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 09/07/2023] [Accepted: 09/10/2023] [Indexed: 09/16/2023] Open
Abstract
Tissue transglutaminase (TG2) is a widely distributed multifunctional protein involved in a broad range of cellular and metabolic functions carried out in a variety of cellular compartments. In addition to transamidation, TG2 also functions as a Gα signaling protein, a protein disulfide isomerase (PDI), a protein kinase, and a scaffolding protein. In the nucleus, TG2 modifies histones and transcription factors. The PDI function catalyzes the trimerization and activation of heat shock factor-1 in the nucleus and regulates the oxidation state of several mitochondrial complexes. Cytosolic TG2 modifies proteins by the addition of serotonin or other primary amines and in this way affects cell signaling. Modification of protein-bound glutamines reduces ubiquitin-dependent proteasomal degradation. At the cell membrane, TG2 is associated with G protein-coupled receptors (GPCRs), where it functions in transmembrane signaling. TG2 is also found in the extracellular space, where it functions in protein cross-linking and extracellular matrix stabilization. Of particular importance in transglutaminase research are recent findings concerning the role of TG2 in gene expression, protein homeostasis, cell signaling, autoimmunity, inflammation, and hypoxia. Thus, TG2 performs a multitude of functions in multiple cellular compartments, making it one of the most versatile cellular proteins. Additional evidence links TG2 with multiple human diseases including preeclampsia, hypertension, cardiovascular disease, organ fibrosis, cancer, neurodegenerative diseases, and celiac disease. In conclusion, TG2 provides a multifunctional and multisite response to physiological stress.
Collapse
Affiliation(s)
- Zhouzhou Yao
- National Medical Metabolomics International Collaborative Research Center, Central South University, Changsha, Hunan, People's Republic of China
- Department of Otolaryngology-Head and Neck Surgery, Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China
| | - Yuhua Fan
- National Medical Metabolomics International Collaborative Research Center, Central South University, Changsha, Hunan, People's Republic of China
- Department of Otolaryngology-Head and Neck Surgery, Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China
| | - Lizhen Lin
- National Medical Metabolomics International Collaborative Research Center, Central South University, Changsha, Hunan, People's Republic of China
- Department of Endocrinology, Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China
| | - Rodney E Kellems
- Department of Biochemistry and Molecular Biology, The University of Texas McGovern Medical School at Houston, Houston, Texas, United States
| | - Yang Xia
- National Medical Metabolomics International Collaborative Research Center, Central South University, Changsha, Hunan, People's Republic of China
- Department of Otolaryngology-Head and Neck Surgery, Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China
| |
Collapse
|
2
|
Syed Mohammed RD, Ablan FDO, McCann NM, Hindi MM, Maurer MC. Transglutaminase Activities of Blood Coagulant Factor XIII Are Dependent on the Activation Pathways and on the Substrates. Thromb Haemost 2023; 123:380-392. [PMID: 36473493 PMCID: PMC10719020 DOI: 10.1055/a-1993-4193] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Factor XIII (FXIII) catalyzes formation of γ-glutamyl-ε-lysyl crosslinks between reactive glutamines (Q) and lysines (K). In plasma, FXIII is activated proteolytically (FXIII-A*) by the concerted action of thrombin and Ca2+. Cellular FXIII is activated nonproteolytically (FXIII-A°) by elevation of physiological Ca2+ concentrations. FXIII-A targets plasmatic and cellular substrates, but questions remain on correlating FXIII activation, resultant conformational changes, and crosslinking function to different physiological substrates. To address these issues, the characteristics of FXIII-A* versus FXIII-A° that contribute to transglutaminase activity and substrate specificities were investigated. Crosslinking of lysine mimics into a series of Q-containing substrates were measured using in-gel fluorescence, mass spectrometry, and UV-Vis spectroscopy. Covalent incorporation of fluorescent monodansylcadaverine revealed that FXIII-A* exhibits greater activity than FXIII-A° toward Q residues within Fbg αC (233-425 WT, Q328P Seoul II, and Q328PQ366N) and actin. FXIII-A* and FXIII-A° displayed similar activities toward α2-antiplasmin (α2AP), fibronectin, and Fbg αC (233-388, missing FXIII-binding site αC 389-402). Furthermore, the N-terminal α2AP peptide (1-15) exhibited similar kinetic properties for FXIII-A* and FXIII-A°. MALDI-TOF mass spectrometry assays with glycine ethyl ester and Fbg αC (233-425 WT, αC E396A, and truncated αC (233-388) further documented that FXIII-A* exerts greater benefit from the αC 389-402 binding site than FXIII-A°. Conformational properties of FXIII-A* versus A° are proposed to help promote transglutaminase function toward different substrates. A combination of protein substrate disorder and secondary FXIII-binding site exposure are utilized to control activity and specificity. From these studies, greater understandings of how FXIII-A targets different substrates are achieved.
Collapse
Affiliation(s)
| | | | | | - Mohammed M. Hindi
- Department of Chemistry, University of Louisville, Louisville, KY, USA
| | - Muriel C. Maurer
- Department of Chemistry, University of Louisville, Louisville, KY, USA
| |
Collapse
|
3
|
Neuronal and Endothelial Transglutaminase-2 Expression during Experimental Autoimmune Encephalomyelitis and Multiple Sclerosis. Neuroscience 2020; 461:140-154. [PMID: 33253822 DOI: 10.1016/j.neuroscience.2020.11.034] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Revised: 11/17/2020] [Accepted: 11/18/2020] [Indexed: 12/17/2022]
Abstract
Transglutiminase-2 (TG2) is a multifunctional enzyme that has been implicated in the pathogenesis of experimental autoimmune encephalomyelitis (EAE) and multiple sclerosis (MS) using global knockout mice and TG2 selective inhibitors. Previous studies have identified the expression of TG2 in subsets of macrophages-microglia and astrocytes after EAE. The aims of the current investigation were to examine neuronal expression of TG2 in rodent models of chronic-relapsing and non-relapsing EAE and through co-staining with intracellular and cell death markers, provide insight into the putative role of TG2 in neuronal pathology during disease progression. Here we report that under normal physiological conditions there is a low basal expression of TG2 in the nucleus of neurons, however following EAE or MS, robust induction of cytoplasmic TG2 occurs in most neurons surrounding perivascular lesion sites. Importantly, TG2-positive neurons also labeled for phosphorylated Extracellular signal-regulated kinase 1/2 (ERK1/2) and the apoptotic marker cleaved caspase-3. In white and gray matter lesions, high levels of TG2 were also found within the vasculature and endothelial cells as well as in tissue migrating pericytes or fibroblasts, though rarely did TG2 colocalize with cells identified with glial cell markers (astrocytes, oligodendrocytes and microglia). TG2 induction occurred concurrently with the upregulation of the blood vessel permeability factor and angiogenic molecule Vascular Endothelial Growth Factor (VEGF). Extracellular TG2 was found to juxtapose with fibronectin, within and surrounding blood vessels. Though molecular and pharmacological studies have implicated TG2 in the induction and severity of EAE, the cell autonomous functions of this multifunctional enzyme during disease progression remains to be elucidated.
Collapse
|
4
|
Characteristic fragment ions associated with dansyl cadaverine and biotin cadaverine adducts on glutamine. Anal Biochem 2020; 600:113718. [PMID: 32335065 DOI: 10.1016/j.ab.2020.113718] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 02/18/2020] [Accepted: 04/03/2020] [Indexed: 12/16/2022]
Abstract
Glutamine residues susceptible to transglutaminase-catalyzed crosslinking can be identified by incorporation of dansyl cadaverine or biotin cadaverine. Bacterial transglutaminase and human transglutaminase 2 were used to modify residues in beta-casein with dansyl cadaverine. Bacterial transglutaminase was used to modify residues in human butyrylcholinesterase with biotin cadaverine. Tryptic peptides were analyzed by LC-MS/MS on an Orbitrap Fusion Lumos mass spectrometer. Modified residues were identified in Protein Prospector searches of mass spectrometry data. The MS/MS spectra from modified casein included intense peaks at 336.2, 402.2, and 447.2 for fragments of dansyl cadaverine adducts on glutamine. The MS/MS spectra from modified butyrylcholinesterase included intense peaks at 329.2, 395.2, and 440.2 for fragments of biotin cadaverine adducts on glutamine. No evidence for transglutaminase-catalyzed adducts on glutamic acid, aspartic acid, or asparagine was found. Consistent with expectation, it was concluded that bacterial transglutaminase and human transglutaminase 2 specifically modify glutamine. The characteristic ions associated with dansyl cadaverine and biotin cadaverine adducts on glutamine are useful markers for modified peptides.
Collapse
|
5
|
Bader M. Serotonylation: Serotonin Signaling and Epigenetics. Front Mol Neurosci 2019; 12:288. [PMID: 31824263 PMCID: PMC6881384 DOI: 10.3389/fnmol.2019.00288] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Accepted: 11/12/2019] [Indexed: 01/01/2023] Open
Abstract
Serotonylation, the covalent linkage of serotonin to proteins has been discovered more than 60 years ago but only recently the mechanisms and first functions have been elucidated. It has been found that transglutaminases (TG) such as TG2 and the blood coagulation factor XIIIa are the enzymes which catalyze the linkage of serotonin and other monoamines to distinct glutamine (Gln) residues of target proteins. The first target proteins, small G-proteins and extracellular matrix constituents, were found in platelets and are pivotally involved in platelet aggregation and the formation of thrombi. The serotonylation of the same proteins is also involved in insulin secretion and in the proliferation of pulmonary vascular smooth muscle cells and thereby in the pathogenesis of pulmonary arterial hypertension (PAH). Recently histones have been described as targets of serotonylation opening the area of transcriptional control to this posttranslational protein modification. Future studies will certainly reveal further target proteins, signaling pathways, cellular processes, and diseases, in which serotonylation or, more general, monoaminylation is important.
Collapse
Affiliation(s)
- Michael Bader
- Max-Delbrück Center for Molecular Medicine, Berlin, Germany.,Institute for Biology, University of Lübeck, Lübeck, Germany.,Charité University Medicine, Berlin, Germany.,German Center for Cardiovascular Research (DZHK), Partner Site Berlin, Berlin, Germany
| |
Collapse
|
6
|
Schmitt LR, Henderson R, Barrett A, Darula Z, Issaian A, D'Alessandro A, Clendenen N, Hansen KC. Mass spectrometry-based molecular mapping of native FXIIIa cross-links in insoluble fibrin clots. J Biol Chem 2019; 294:8773-8778. [PMID: 31028172 DOI: 10.1074/jbc.ac119.007981] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 04/22/2019] [Indexed: 12/31/2022] Open
Abstract
The roles of factor XIIIa-specific cross-links in thrombus formation, regression, or probability for embolization are largely unknown. A molecular understanding of fibrin architecture at the level of these cross-links could inform the development of therapeutic strategies to prevent the sequelae of thromboembolism. Here, we present an MS-based method to map native factor XIIIa cross-links in the insoluble matrix component of whole-blood or plasma-fibrin clots and in in vivo thrombi. Using a chaotrope-insoluble digestion method and quantitative cross-linking MS, we identified the previously mapped fibrinogen peptides that are responsible for covalent D-dimer association, as well as dozens of novel cross-links in the αC region of fibrinogen α. Our findings expand the known native cross-linked species from one to over 100 and suggest distinct antiparallel registries for interprotofibril association and covalent attachment of serpins that regulate clot dissolution.
Collapse
Affiliation(s)
| | - Rachel Henderson
- Anesthesiology, University of Colorado School of Medicine, Aurora, Colorado 80045 and
| | | | - Zsuzsanna Darula
- Laboratory of Proteomics Research, Biological Research Center of the Hungarian Academy of Sciences, H-6701 Szeged, Hungary
| | - Aaron Issaian
- From the Departments of Biochemistry and Molecular Genetics and
| | | | - Nathan Clendenen
- Anesthesiology, University of Colorado School of Medicine, Aurora, Colorado 80045 and
| | - Kirk C Hansen
- From the Departments of Biochemistry and Molecular Genetics and
| |
Collapse
|
7
|
Fibronectin Facilitates Enterovirus 71 Infection by Mediating Viral Entry. J Virol 2018; 92:JVI.02251-17. [PMID: 29467312 DOI: 10.1128/jvi.02251-17] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 02/13/2018] [Indexed: 11/20/2022] Open
Abstract
Fibronectin (FN) is a high-molecular-weight extracellular matrix protein that contains the RGDS motif, which is required to bind to integrins. Synthetic RGDS peptides have been reported to compete with FN to bind to the cell surface and inhibit the function of FN. Here, we identified that synthetic RGDS peptides significantly inhibit human enterovirus 71 (EV71) infection in cell cultures. In addition, mice treated with RGDS peptides and infected with EV71 had a significantly higher survival rate and a lower viral load than the control group. Because RGDS peptides affect the function of FN, we questioned whether FN may play a role in virus infection. Our study indicates that overexpression of FN enhanced EV71 infection. In contrast, knockout of FN significantly reduced viral yield and decreased the viral binding to host cells. Furthermore, EV71 entry, rather than intracellular viral replication, was blocked by FN inhibitor pretreatment. Next, we found that FN could interact with the EV71 capsid protein VP1, and further truncated-mutation assays indicated that the D2 domain of FN could interact with the N-terminal fragment of VP1. Taken together, our results demonstrate that the host factor FN binds to EV71 particles and facilitates EV71 entry, providing a potential therapy target for EV71 infection.IMPORTANCE Hand, foot, and mouth disease outbreaks have occurred frequently in recent years, sometimes causing severe neurological complications and even death in infants and young children worldwide. Unfortunately, no effective antiviral drugs are available for human enterovirus 71 (EV71), one of the viruses that cause hand, foot, and mouth disease. The infection process and the host factors involved remain unknown, although several receptors have been identified. In this study, we found that the host factor fibronectin (FN) facilitated EV71 replication by interacting with EV71 particles and further mediated their entry. The RGDS peptide, an FN inhibitor, significantly inhibited EV71 replication in both RD cells and mice. In conclusion, our research identified a new host factor involved in EV71 infection, providing a new potential antiviral target for EV71 treatment.
Collapse
|
8
|
|
9
|
Abstract
Fibronectin is a large vertebrate glycoprotein that is found in soluble and insoluble forms and involved in diverse processes. Protomeric fibronectin is a dimer of subunits, each of which comprises 29-31 modules - 12 type I, two type II and 15-17 type III. Plasma fibronectin is secreted by hepatocytes and circulates in a compact conformation before it binds to cell surfaces, converts to an extended conformation and is assembled into fibronectin fibrils. Here we review biophysical and structural studies that have shed light on how plasma fibronectin transitions from the compact to the extended conformation. The three types of modules each have a well-organized secondary and tertiary structure as defined by NMR and crystallography and have been likened to "beads on a string". There are flexible sequences in the N-terminal tail, between the fifth and sixth type I modules, between the first two and last two of the type III modules, and at the C-terminus. Several specific module-module interactions have been identified that likely maintain the compact quaternary structure of circulating fibronectin. The quaternary structure is perturbed in response to binding events, including binding of fibronectin to the surface of vertebrate cells for fibril assembly and to bacterial adhesins.
Collapse
Affiliation(s)
- Lisa M Maurer
- a Departments of Biomolecular Chemistry and Medicine , University of Wisconsin-Madison , Madison , WI , United States
| | - Wenjiang Ma
- a Departments of Biomolecular Chemistry and Medicine , University of Wisconsin-Madison , Madison , WI , United States
| | - Deane F Mosher
- a Departments of Biomolecular Chemistry and Medicine , University of Wisconsin-Madison , Madison , WI , United States
| |
Collapse
|
10
|
Ranking reactive glutamines in the fibrinogen αC region that are targeted by blood coagulant factor XIII. Blood 2016; 127:2241-8. [PMID: 26951791 DOI: 10.1182/blood-2015-09-672303] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2015] [Accepted: 02/24/2016] [Indexed: 01/09/2023] Open
Abstract
Factor XIIIa (FXIIIa) introduces covalent γ-glutamyl-ε-lysyl crosslinks into the blood clot network. These crosslinks involve both the γ and α chains of fibrin. The C-terminal portion of the fibrin α chain extends into the αC region (210-610). Crosslinks within this region help generate a stiffer clot, which is more resistant to fibrinolysis. Fibrinogen αC (233-425) contains a binding site for FXIIIa and three glutamines Q237, Q328, and Q366 that each participate in physiological crosslinking reactions. Although these glutamines were previously identified, their reactivities toward FXIIIa have not been ranked. Matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry and nuclear magnetic resonance (NMR) methods were thus used to directly characterize these three glutamines and probe for sources of FXIIIa substrate specificity. Glycine ethyl ester (GEE) and ammonium chloride served as replacements for lysine. Mass spectrometry and 2D heteronuclear single quantum coherence NMR revealed that Q237 is rapidly crosslinked first by FXIIIa followed by Q366 and Q328. Both (15)NH4Cl and (15)N-GEE could be crosslinked to the three glutamines in αC (233-425) with a similar order of reactivity as observed with the MALDI-TOF mass spectrometry assay. NMR studies using the single αC mutants Q237N, Q328N, and Q366N demonstrated that no glutamine is dependent on another to react first in the series. Moreover, the remaining two glutamines of each mutant were both still reactive. Further characterization of Q237, Q328, and Q366 is important because they are located in a fibrinogen region susceptible to physiological truncations and mutation. The current results suggest that these glutamines play distinct roles in fibrin crosslinking and clot architecture.
Collapse
|
11
|
Enhanced B-Cell Receptor Recognition of the Autoantigen Transglutaminase 2 by Efficient Catalytic Self-Multimerization. PLoS One 2015; 10:e0134922. [PMID: 26244572 PMCID: PMC4526674 DOI: 10.1371/journal.pone.0134922] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 07/10/2015] [Indexed: 12/20/2022] Open
Abstract
A hallmark of the gluten-driven enteropathy celiac disease is autoantibody production towards the enzyme transglutaminase 2 (TG2) that catalyzes the formation of covalent protein-protein cross-links. Activation of TG2-specific B cells likely involves gluten-specific CD4 T cells as production of the antibodies is dependent on disease-associated HLA-DQ allotypes and dietary intake of gluten. IgA plasma cells producing TG2 antibodies with few mutations are abundant in the celiac gut lesion. These plasma cells and serum antibodies to TG2 drop rapidly after initiation of a gluten-free diet, suggestive of extrafollicular responses or germinal center reactions of short duration. High antigen avidity is known to promote such responses, and is also important for breakage of self-tolerance. We here inquired whether TG2 avidity could be a feature relevant to celiac disease. Using recombinant enzyme we show by dynamic light scattering and gel electrophoresis that TG2 efficiently utilizes itself as a substrate due to conformation-dependent homotypic association, which involves the C-terminal domains of the enzyme. This leads to the formation of covalently linked TG2 multimers. The presence of exogenous substrate such as gluten peptide does not inhibit TG2 self-cross-linking, but rather results in formation of TG2-TG2-gluten complexes. The celiac disease autoantibody epitopes, clustered in the N-terminal part of TG2, are conserved in the TG2-multimers as determined by mass spectrometry and immunoprecipitation analysis. TG2 multimers are superior to TG2 monomer in activating A20 B cells transduced with TG2-specific B-cell receptor, and uptake of TG2-TG2-gluten multimers leads to efficient activation of gluten-specific T cells. Efficient catalytic self-multimerization of TG2 and generation of multivalent TG2 antigen decorated with gluten peptides suggest a mechanism by which self-reactive B cells are activated to give abundant numbers of plasma cells in celiac disease. Importantly, high avidity of the antigen could explain why TG2-specific plasma cells show signs of an extrafollicular generation pathway.
Collapse
|
12
|
Cardoso I, Stamnaes J, Andersen JT, Melino G, Iversen R, Sollid LM. Transglutaminase 2 interactions with extracellular matrix proteins as probed with celiac disease autoantibodies. FEBS J 2015; 282:2063-75. [PMID: 25808416 DOI: 10.1111/febs.13276] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Revised: 03/02/2015] [Accepted: 03/20/2015] [Indexed: 11/29/2022]
Abstract
Transglutaminases have been implicated in various human diseases. A prominent example is the involvement of transglutaminase 2 (TG2) in the gluten-sensitive enteropathy celiac disease, where the enzyme is both the target of autoantibodies and responsible for the generation of immunogenic gluten epitopes. Here, we aimed to characterize the microenvironment of TG2 in the extracellular matrix (ECM) in order to gain insights into the antigenic structures that are recognized by autoantibodies in celiac disease. A panel of TG2-specific mAbs established from gut plasma cells of celiac disease patients was employed as probes to characterize the interactions between TG2 and ECM constituents. With immunofluorescence staining, microplate protein-binding and surface plasmon resonance assays, we found that the main epitope (epitope 1) recognized by TG2-specific gut plasma cells overlaps with the fibronectin (FN)-binding site of TG2. Furthermore, we found that the same TG2 amino acids that are involved in binding of epitope 1 mAbs are also important for efficient binding of FN. Notably, epitope 1 mAbs recognize TG2 in tissue sections, suggesting that some TG2 in the extracellular matrix has interaction partners in addition to FN. We demonstrate that collagen VI is a strong candidate, on the basis of its tissue expression pattern and ability to bind TG2. Collagen VI may thus serve as a matrix for deposition of TG2 in a context that can also be recognized by epitope 1-targeting autoantibodies.
Collapse
Affiliation(s)
- Inês Cardoso
- Centre for Immune Regulation and Department of Immunology, University of Oslo and Oslo University Hospital, Oslo, Norway
| | - Jorunn Stamnaes
- Centre for Immune Regulation and Department of Immunology, University of Oslo and Oslo University Hospital, Oslo, Norway
| | - Jan Terje Andersen
- Centre for Immune Regulation and Department of Immunology, University of Oslo and Oslo University Hospital, Oslo, Norway
| | - Gerry Melino
- Medical Research Council Toxicology Unit, Leicester, UK.,Department of Experimental Medicine and Surgery, University of Rome "Tor Vergata", Rome, Italy
| | - Rasmus Iversen
- Centre for Immune Regulation and Department of Immunology, University of Oslo and Oslo University Hospital, Oslo, Norway
| | - Ludvig M Sollid
- Centre for Immune Regulation and Department of Immunology, University of Oslo and Oslo University Hospital, Oslo, Norway
| |
Collapse
|
13
|
Activity-regulating structural changes and autoantibody epitopes in transglutaminase 2 assessed by hydrogen/deuterium exchange. Proc Natl Acad Sci U S A 2014; 111:17146-51. [PMID: 25404341 DOI: 10.1073/pnas.1407457111] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The multifunctional enzyme transglutaminase 2 (TG2) is the target of autoantibodies in the gluten-sensitive enteropathy celiac disease. In addition, the enzyme is responsible for deamidation of gluten peptides, which are subsequently targeted by T cells. To understand the regulation of TG2 activity and the enzyme's role as an autoantigen in celiac disease, we have addressed structural properties of TG2 in solution by using hydrogen/deuterium exchange monitored by mass spectrometry. We demonstrate that Ca(2+) binding, which is necessary for TG2 activity, induces structural changes in the catalytic core domain of the enzyme. Cysteine oxidation was found to abolish these changes, suggesting a mechanism whereby disulfide bond formation inactivates the enzyme. Further, by using TG2-specific human monoclonal antibodies generated from intestinal plasma cells of celiac disease patients, we observed that binding of TG2 by autoantibodies can induce structural changes that could be relevant for the pathogenesis. Detailed mapping of two of the main epitopes targeted by celiac disease autoantibodies revealed that they are located adjacent to each other in the N-terminal part of the TG2 molecule.
Collapse
|
14
|
|
15
|
Factor XIII-A transglutaminase acts as a switch between preadipocyte proliferation and differentiation. Blood 2014; 124:1344-53. [PMID: 24934257 DOI: 10.1182/blood-2013-12-543223] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Factor XIII-A (FXIII-A) transglutaminase (TG) was recently identified as a potential causative obesity gene in human white adipose tissue (WAT). Here, we have examined the role of TG activity and the role of protein crosslinking in adipogenesis. Mouse WAT and preadipocytes showed abundant TG activity arising from FXIII-A. FXIII-A was localized to the cell surface and acted as a negative regulator of adipogenesis by promoting assembly of fibronectin (FN) from plasma into preadipocyte extracellular matrix. This modulated cytoskeletal dynamics and maintained the preadipocyte state. FXIII-A-assembled plasma FN (pFN) matrix promoted preadipocyte proliferation and potentiated the proproliferative effects of insulin (INS) while suppressing the prodifferentiating INS signaling. FXIII-A-deficient mouse embryonic fibroblasts showed increased lipid accumulation and decreased proliferation as well as decreased pFN assembly into extracellular matrix. Thus, FXIII-A serves as a preadipocyte-bound proliferation/differentiation switch that mediates effects of hepatocyte-produced circulating pFN.
Collapse
|
16
|
Früh SM, Spycher PR, Mitsi M, Burkhardt MA, Vogel V, Schoen I. Functional Modification of Fibronectin by N-Terminal FXIIIa-Mediated Transamidation. Chembiochem 2014; 15:1481-6. [DOI: 10.1002/cbic.201402099] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Indexed: 01/09/2023]
|
17
|
Cui C, Wang S, Myneni VD, Hitomi K, Kaartinen MT. Transglutaminase activity arising from Factor XIIIA is required for stabilization and conversion of plasma fibronectin into matrix in osteoblast cultures. Bone 2014; 59:127-38. [PMID: 24246248 DOI: 10.1016/j.bone.2013.11.006] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Revised: 11/08/2013] [Accepted: 11/10/2013] [Indexed: 11/19/2022]
Abstract
Circulating plasma fibronectin (pFN), produced by hepatocytes, is a major component of the noncollagenous bone matrix where it was recently shown in vivo in mice to control the biomechanical quality as well as the mineral-to-matrix ratio in bone. FN fibrillogenesis is a process generally requiring FN binding to cellular integrins, and cellular tension to elongate and assemble the molecule. Whether soluble pFN undergoes cell-mediated assembly in bone is not fully established. FN is a well-known substrate for transglutaminases (TGs), which are protein-crosslinking enzymes capable of stabilizing macromolecular structures. The role of this modification regarding the function of FN in bone matrix has remained unknown. Osteoblasts express two TGs-transglutaminase 2 and Factor XIIIA-and we have shown that Factor XIIIA is the main TG active during osteoblast differentiation. In the present study, conducted using MC3T3-E1 osteoblast cultures and bone marrow stromal cells, we demonstrate that pFN requires a TG-mediated crosslinking step to form osteoblast matrix in vitro. This modification step is specific for pFN; cellular FN (EDA-FN) does not serve as a TG substrate. Inhibition of pFN assembly using a TG inhibitor, or depletion of pFN from cell culture serum, dramatically decreased total FN matrix assembly in the osteoblast cultures and affected both the quantity and quality of the type I collagen matrix, and decreased lysyl oxidase and alkaline phosphatase levels, resulting in decreased mineralization. Experiments with isozyme-specific substrate peptides showed that FXIIIA is responsible for the crosslinking of pFN. Addition of exogenous preactivated FXIIIA to osteoblast cultures promoted pFN assembly from the media into matrix. Exogenous TG2 had no effect. Analysis of pFN and EDA-FN fibrils by immunofluorescence microscopy demonstrated that they form distinct matrix network, albeit with minor overlap, suggesting different functions for the two FN forms. Further analysis using EDA-FN blocking antibody showed that it regulated preosteoblast proliferation whereas pFN depletion from the serum had no effect on this process. In conclusion, our study shows that pFN assembly into bone matrix in vitro requires FXIIIA transglutaminase activity making pFN assembly an active, osteoblast-mediated process.
Collapse
Affiliation(s)
- Cui Cui
- Division of Biomedical Sciences, Faculty of Dentistry, McGill University, Montreal, QC, Canada
| | - Shuai Wang
- Division of Biomedical Sciences, Faculty of Dentistry, McGill University, Montreal, QC, Canada
| | - Vamsee D Myneni
- Division of Biomedical Sciences, Faculty of Dentistry, McGill University, Montreal, QC, Canada
| | - Kiyotaka Hitomi
- Department of Applied Molecular Biosciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa, Nagoya, Japan
| | - Mari T Kaartinen
- Division of Biomedical Sciences, Faculty of Dentistry, McGill University, Montreal, QC, Canada; Division of Experimental Medicine, Department of Medicine, Faculty of Medicine, McGill University, Montreal, QC, Canada.
| |
Collapse
|
18
|
Abstract
Fibrillins constitute the backbone of extracellular multifunctional assemblies present in elastic and non-elastic matrices, termed microfibrils. Assembly of fibrillins into microfibrils and their homoeostasis is poorly understood and is often compromised in connective tissue disorders such as Marfan syndrome and other fibrillinopathies. Using interaction mapping studies, we demonstrate that fibrillins require the complete gelatin-binding region of fibronectin for interaction, which comprises domains FNI6-FNI9. However, the interaction of fibrillin-1 with the gelatin-binding domain of fibronectin is not involved in fibrillin-1 network assembly mediated by human skin fibroblasts. We show further that the fibronectin network is essential for microfibril homoeostasis in early stages. Fibronectin is present in extracted mature microfibrils from tissue and cells as well as in some in situ microfibrils observed at the ultrastructural level, indicating an extended mechanism for the involvement of fibronectin in microfibril assembly and maturation.
Collapse
|
19
|
Penumatsa KC, Fanburg BL. Transglutaminase 2-mediated serotonylation in pulmonary hypertension. Am J Physiol Lung Cell Mol Physiol 2013; 306:L309-15. [PMID: 24375797 DOI: 10.1152/ajplung.00321.2013] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The monoamine serotonin (5-HT) has been previously implicated in pulmonary arterial remodeling and is considered a potential therapeutic target for the disease pulmonary arterial hypertension (PAH). More recently, it has been recognized that the enzyme tissue transglutaminase (TG2) mediates cross-linking of proteins with 5-HT, a posttranslational process of monoaminylation known as "serotonylation." TG2 activity and serotonylation of protein participate in both smooth muscle proliferation and contraction produced by 5-HT. Indeed, markedly increased TG2 activity has now been identified in lung tissue of an experimental rodent model of pulmonary hypertension, and elevated serotonylation of fibronectin and the signaling molecule Rho, downstream products of transglutamidation, have been found in blood of patients with PAH. The basic mechanism by which TG2 is activated and the potential role(s) of serotonylated proteins in pulmonary hypertension remain a mystery. In the present review we have tried to address the current understanding of 5-HT metabolism in pulmonary hypertension and relate it to what is currently known about the evolving cellular process of serotonylation.
Collapse
Affiliation(s)
- K C Penumatsa
- Pulmonary, Critical Care and Sleep Division, Tufts Medical Center, 800 Washington St., #257, Boston, MA 02111.
| | | |
Collapse
|
20
|
Identification of a novel zinc metalloprotease through a global analysis of Clostridium difficile extracellular proteins. PLoS One 2013; 8:e81306. [PMID: 24303041 PMCID: PMC3841139 DOI: 10.1371/journal.pone.0081306] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Accepted: 10/11/2013] [Indexed: 01/05/2023] Open
Abstract
Clostridium difficile is a major cause of infectious diarrhea worldwide. Although the cell surface proteins are recognized to be important in clostridial pathogenesis, biological functions of only a few are known. Also, apart from the toxins, proteins exported by C. difficile into the extracellular milieu have been poorly studied. In order to identify novel extracellular factors of C. difficile, we analyzed bacterial culture supernatants prepared from clinical isolates, 630 and R20291, using liquid chromatography-tandem mass spectrometry. The majority of the proteins identified were non-canonical extracellular proteins. These could be largely classified into proteins associated to the cell wall (including CWPs and extracellular hydrolases), transporters and flagellar proteins. Seven unknown hypothetical proteins were also identified. One of these proteins, CD630_28300, shared sequence similarity with the anthrax lethal factor, a known zinc metallopeptidase. We demonstrated that CD630_28300 (named Zmp1) binds zinc and is able to cleave fibronectin and fibrinogen in vitro in a zinc-dependent manner. Using site-directed mutagenesis, we identified residues important in zinc binding and enzymatic activity. Furthermore, we demonstrated that Zmp1 destabilizes the fibronectin network produced by human fibroblasts. Thus, by analyzing the exoproteome of C. difficile, we identified a novel extracellular metalloprotease that may be important in key steps of clostridial pathogenesis.
Collapse
|
21
|
Iversen R, Di Niro R, Stamnaes J, Lundin KEA, Wilson PC, Sollid LM. Transglutaminase 2-specific autoantibodies in celiac disease target clustered, N-terminal epitopes not displayed on the surface of cells. THE JOURNAL OF IMMUNOLOGY 2013; 190:5981-91. [PMID: 23690478 DOI: 10.4049/jimmunol.1300183] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The gluten-sensitive enteropathy celiac disease is tightly associated with the production of autoantibodies specific for the enzyme transglutaminase 2 (TG2). The mechanisms underlying the activation of autoreactive B cells, however, are not well defined. To gain more insight into this autoimmune response we have characterized the binding of TG2 by a panel of human mAbs generated by expression cloning of Ig genes from single plasma cells of the celiac disease lesion. The Abs were highly specific to TG2 and bound preferentially to the open, Ca(2+)-activated enzyme conformation. Epitope mapping revealed that they recognize few distinct conformational epitopes that cluster in the N-terminal half of the enzyme. Two of the epitopes were overlapping with the fibronectin binding site in TG2, and none of the epitopes was accessible when TG2 was in a cell surface-bound form. Based on our findings, we propose that the autoantibodies are generated against the soluble, catalytically active enzyme, whereas Abs reactive with cell surface-associated TG2 are absent from the response due to negative selection of B cells recognizing membrane-bound self-Ag. The findings give insight into the mechanisms controlling the formation of anti-TG2 autoantibodies in celiac disease.
Collapse
Affiliation(s)
- Rasmus Iversen
- Centre for Immune Regulation, University of Oslo and Oslo University Hospital, N-0372 Oslo, Norway
| | | | | | | | | | | |
Collapse
|
22
|
Lin JCY, Chou CC, Gao S, Wu SC, Khoo KH, Lin CH. An in Vivo Tagging Method Reveals that Ras Undergoes Sustained Activation upon Transglutaminase-Mediated Protein Serotonylation. Chembiochem 2013; 14:813-7. [DOI: 10.1002/cbic.201300050] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Indexed: 12/17/2022]
|
23
|
Tsujimoto I, Moriya K, Sakai K, Dickneite G, Sakai T. Critical role of factor XIII in the initial stages of carbon tetrachloride-induced adult liver remodeling. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 179:3011-9. [PMID: 22019897 PMCID: PMC3260829 DOI: 10.1016/j.ajpath.2011.08.037] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2011] [Revised: 08/05/2011] [Accepted: 08/24/2011] [Indexed: 12/29/2022]
Abstract
The transglutaminase-mediated, covalent cross-linking of proteins is an essential step in tissue remodeling after injury. This process provides tissues with extra rigidity and resistance against proteolytic degradation. Plasma coagulation factor XIII (FXIII) is a transglutaminase that promotes cross-linking of the extracellular matrix (ECM) components fibrin and fibronectin to form a provisional matrix in response to tissue damage. However, the functional requirement for this FXIII-mediated cross-linked provisional matrix in adult tissue remodeling remains to be defined. Although it has been proposed that the formation FXIII-mediated fibrin-fibronectin provisional matrix is a critical step for ECM remodeling, we show in an FXIII subunit A-deficient murine model of acute liver injury that the lack of FXIII subunit A did not interfere with collagen reconstruction and resolution after liver injury. Furthermore, FXIIIA deficiency caused significantly increased hepatocyte apoptosis and a delay in hepatocyte regeneration after injury, which were accompanied by a significantly high induction of p53 expression. These findings suggest novel functions of FXIII that the FXIII-mediated covalently cross-linked matrix could promote survival signals for hepatocytes in adult tissue remodeling.
Collapse
Affiliation(s)
- Ikuko Tsujimoto
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195, USA
| | | | | | | | | |
Collapse
|