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Journal of Thrombosis and Haemostasis :... Dec 2006Allosteric disulfide bonds control protein function by mediating conformational change when they undergo reduction or oxidation. The known allosteric disulfide bonds are... (Review)
Review
Allosteric disulfide bonds control protein function by mediating conformational change when they undergo reduction or oxidation. The known allosteric disulfide bonds are characterized by a particular bond geometry, the -RHStaple. A number of thrombosis and thrombolysis proteins contain one or more disulfide bonds of this type. Tissue factor (TF) was the first hemostasis protein shown to be controlled by an allosteric disulfide bond, the Cys186-Cys209 bond in the membrane-proximal fibronectin type III domain. TF exists in three forms on the cell surface: a cryptic form that is inert, a coagulant form that rapidly binds factor VIIa to initiate coagulation, and a signaling form that binds FVIIa and cleaves protease-activated receptor 2, which functions in inflammation, tumor progression and angiogenesis. Reduction and oxidation of the Cys186-Cys209 disulfide bond is central to the transition between the three forms of TF. The redox state of the bond appears to be controlled by protein disulfide isomerase and NO. Plasmin(ogen), vitronectin, glycoprotein 1balpha, integrin beta(3) and thrombomodulin also contain -RHStaple disulfides, and there is circumstantial evidence that the function of these proteins may involve cleavage/formation of these disulfide bonds.
Topics: Allosteric Site; Animals; Blood Proteins; Disulfides; Enzyme Activation; Fibrinolysin; Fibrinolysis; Glycoproteins; Humans; Immunoglobulins; Integrin beta3; Oxidation-Reduction; Plasminogen; Protein Binding; Protein Conformation; Thrombomodulin; Thromboplastin; Thrombosis; Vitronectin
PubMed: 17002656
DOI: 10.1111/j.1538-7836.2006.02236.x -
International Journal of Cancer Oct 2016Like many cancers, an early diagnosis of melanoma is fundamental to ensure a good prognosis, although an important proportion of stage I-II patients may still develop...
Like many cancers, an early diagnosis of melanoma is fundamental to ensure a good prognosis, although an important proportion of stage I-II patients may still develop metastasis during follow-up. The aim of this work was to discover serum biomarkers in patients diagnosed with primary melanoma that identify those at a high risk of developing metastasis during the follow-up period. Proteomic and mass spectrophotometry analysis was performed on serum obtained from patients who developed metastasis during the first years after surgery for primary tumors and compared with that from patients who remained disease-free for more than 10 years after surgery. Five proteins were selected for validation as prognostic factors in 348 melanoma patients and 100 controls by ELISA: serum amyloid A and clusterin; immune system proteins; the cell adhesion molecules plakoglobin and vitronectin and the antimicrobial protein dermcidin. Compared to healthy controls, melanoma patients have high serum levels of these proteins at the moment of melanoma diagnosis, although the specific values were not related to the histopathological stage of the tumors. However, an analysis based on classification together with multivariate statistics showed that tumor stage, vitronectin and dermcidin levels were associated with the metastatic progression of patients with early-stage melanoma. Although melanoma patients have increased serum dermcidin levels, the REPTree classifier showed that levels of dermcidin <2.98 μg/ml predict metastasis in AJCC stage II patients. These data suggest that vitronectin and dermcidin are potent biomarkers of prognosis, which may help to improve the personalized medical care of melanoma patients and their survival.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Biomarkers, Tumor; Disease Progression; Female; Humans; Male; Melanoma; Middle Aged; Neoplasm Metastasis; Neoplasm Staging; Peptides; Vitronectin; Young Adult
PubMed: 27216146
DOI: 10.1002/ijc.30202 -
Journal of Biomedical Nanotechnology Jun 2013Improvements in osteoconduction of implant biomaterials require focusing on the bone-implant interface, which is a complex multifactorial system. Surface topography of...
Improvements in osteoconduction of implant biomaterials require focusing on the bone-implant interface, which is a complex multifactorial system. Surface topography of implants plays a crucial role at this interface. Nanostructured surfaces have been shown to promote serum protein adsorption and osteoblast adhesion when compared to micro-structured surfaces for bone-implant materials. We studied the influence of the serum proteins fibronectin and vitronectin on the attachment and proliferation of osteoblasts onto nanostructured titania surfaces. Human fetal osteoblastic cells hFOB 1.19 were used as model osteoblasts and were grown on nanoporous TiO2 templates, using Ti6AI4V and commercially pure Ti substrates as controls. Results show a significant increase in cell proliferation'on nanoporous TiO2 over flat substrates. Initial cell attachment data exhibited a significant effect by either fibronectin or vitronectin on cell adhesion at the surface of any of the tested materials. In addition, the extent of cell adhesion was significantly different between the nanoporous TiO2 and both Ti6AI4V and commercially pure Ti substrates, with the first showing the highest surface coverage. There was no significant difference on osteoblast attachment or proliferation between the presence of fibronectin or vitronectin using any of the material substrates. Taken together, these results suggest that the increase in osteoblast attachment and proliferation shown on the nanoporous TiO2 is due to an increase in the adsorption of fibronectin and vitronectin because of the higher surface area and to an enhanced protein unfolding, which allows access to osteoblast binding motifs within these proteins.
Topics: Cell Adhesion; Cell Line; Cell Proliferation; Coated Materials, Biocompatible; Fibronectins; Macromolecular Substances; Materials Testing; Molecular Conformation; Nanostructures; Osteoblasts; Osteogenesis; Particle Size; Porosity; Surface Properties; Titanium; Vitronectin
PubMed: 23858975
DOI: 10.1166/jbn.2013.1601 -
Infection and Immunity Feb 2009Resisting the bactericidal activity of naturally occurring antibodies and complement of normal human serum is an important element in the evasion of innate immunity by...
Localization of the domains of the Haemophilus ducreyi trimeric autotransporter DsrA involved in serum resistance and binding to the extracellular matrix proteins fibronectin and vitronectin.
Resisting the bactericidal activity of naturally occurring antibodies and complement of normal human serum is an important element in the evasion of innate immunity by bacteria. In the gram-negative mucosal pathogen Haemophilus ducreyi, serum resistance is mediated primarily by the trimeric autotransporter DsrA. DsrA also functions as an adhesin for the extracellular matrix proteins fibronectin and vitronectin and mediates attachment of H. ducreyi to keratinocytes. We sought to determine the domain(s) of the 236-residue DsrA protein required for serum resistance and extracellular matrix protein binding. A 140-amino-acid truncated protein containing only the C-terminal portion of the passenger domain and the entire translocator domain of DsrA exhibited binding to fibronectin and vitronectin and conferred serum resistance to an H. ducreyi serum-sensitive strain. A shorter DsrA construct consisting of only 128 amino acids was unable to bind to extracellular matrix proteins but was serum resistant. We concluded that neither fibronectin binding nor vitronectin binding is required for high-level serum resistance in H. ducreyi.
Topics: Amino Acid Sequence; Bacterial Adhesion; Bacterial Proteins; Carrier Proteins; Cell Membrane; Extracellular Matrix; Fibronectins; Gene Deletion; Gene Expression Profiling; Gene Expression Regulation, Bacterial; Haemophilus ducreyi; Molecular Sequence Data; Protein Binding; Protein Structure, Tertiary; Vitronectin
PubMed: 19015257
DOI: 10.1128/IAI.00819-08 -
BioMed Research International 2013After traumatic injuries to the nervous system, regrowing axons encounter a complex microenvironment where mechanisms that promote regeneration compete with inhibitory... (Review)
Review
After traumatic injuries to the nervous system, regrowing axons encounter a complex microenvironment where mechanisms that promote regeneration compete with inhibitory processes. Sprouting and axonal regrowth are key components of functional recovery but are often counteracted by inhibitory molecules. This review covers extracellular matrix molecules that support neuron axonal outgrowth.
Topics: Animals; Cells, Cultured; Disease Models, Animal; Extracellular Matrix Proteins; Fibronectins; Humans; Integrins; Laminin; Nerve Regeneration; Nerve Tissue Proteins; Neurons; Osteopontin; Peripheral Nerve Injuries; Spinal Cord Injuries; Thrombospondins; Vitronectin
PubMed: 24195084
DOI: 10.1155/2013/981695 -
Blood Sep 1986Vitronectin (serum spreading factor), a major serum cell adhesion molecule, was compared with S-protein, the inhibitor of the C5-9 membrane attack complex. Data from the...
Vitronectin (serum spreading factor), a major serum cell adhesion molecule, was compared with S-protein, the inhibitor of the C5-9 membrane attack complex. Data from the literature indicate that S-protein and vitronectin are alpha globulins with the same aminoterminal residues, amino acid compositions, and concentrations in normal plasma (150 to 250 micrograms/mL). Both proteins have been reported to interact with the thrombin-antithrombin complex. The cDNA sequences of vitronectin and S-protein were recently determined and found to be almost identical. In the present studies, rabbit-anti-S-protein and a monoclonal antibody to vitronectin both recognized 65,000- and 75,000-molecular weight (mol wt) polypeptides when plasma or serum proteins were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and transferred to nitrocellulose paper. The 65,000 and 75,000-mol wt polypeptides bound more avidly from serum than plasma to monoclonal anti-vitronectin or heparin coupled to agarose. The presence or absence of the polypeptides constituted a major difference between the heparin-binding proteins of serum and plasma. When complement-activated serum and unactivated serum were separated by gel filtration, vitronectin coeluted with C9 in high-mol-wt fractions of activated serum but not unactivated serum. Purified S-protein was recognized by the monoclonal antibody to vitronectin and promoted spreading of human skin fibroblasts. Both vitronectin and S-protein were degraded by thrombin. On the basis of immunological and functional, as well as biochemical, properties, therefore, S-protein and vitronectin are the same.
Topics: Glycoproteins; Humans; Immunologic Techniques; Molecular Weight; Thrombin; Vitronectin
PubMed: 2427139
DOI: No ID Found -
American Journal of Physiology. Lung... Jun 2016Transforming growth factor-β (TGF-β) is a critical driver of acute lung injury and fibrosis. Injury leads to activation of TGF-β, which regulates changes in the...
Transforming growth factor-β (TGF-β) is a critical driver of acute lung injury and fibrosis. Injury leads to activation of TGF-β, which regulates changes in the cellular and matrix makeup of the lung during the repair and fibrosis phase. TGF-β can also initiate alveolar epithelial cell (AEC) apoptosis. Injury leads to destruction of the laminin-rich basement membrane, which is replaced by a provisional matrix composed of arginine-glycine-aspartate (RGD) motif-containing plasma matrix proteins, including vitronectin and fibronectin. To determine the role of specific matrix proteins on TGF-β-induced apoptosis, we studied primary AECs cultured on different matrix conditions and utilized mice with deletion of vitronectin (Vtn(-/-)) or mice in which the vitronectin RGD motif is mutated to nonintegrin-binding arginine-glycine-glutamate (RGE) (Vtn(RGE/RGE)). We found that AECs cultured on fibronectin and vitronectin or in wild-type mouse serum are resistant to TGF-β-induced apoptosis. In contrast, AECs cultured on laminin or in serum from Vtn(-/-) or Vtn(RGE/RGE) mice undergo robust TGF-β-induced apoptosis. Plasminogen activator inhibitor-1 (PAI-1) sensitizes AECs to greater apoptosis by disrupting AEC engagement to vitronectin. Inhibition of integrin-associated signaling proteins augments AEC apoptosis. Mice with transgenic deletion of PAI-1 have less apoptosis after bleomycin, but deletion of vitronectin or disruption of the vitronectin RGD motif reverses this protection, suggesting that the proapoptotic function of PAI-1 is mediated through vitronectin inhibition. Collectively, these data suggest that integrin-matrix signaling is an important regulator of TGF-β-mediated AEC apoptosis and that PAI-1 functions as a natural regulator of this interaction.
Topics: Alveolar Epithelial Cells; Amino Acid Motifs; Animals; Apoptosis; Cells, Cultured; Integrins; Mice, Inbred C57BL; Mice, Knockout; Protein Interaction Domains and Motifs; Signal Transduction; Transforming Growth Factor beta; Vitronectin
PubMed: 27106291
DOI: 10.1152/ajplung.00424.2015 -
EMBO Reports Jul 2016Components of the plasminogen activation system including urokinase (uPA), its inhibitor (PAI-1) and its cell surface receptor (uPAR) have been implicated in a wide...
Components of the plasminogen activation system including urokinase (uPA), its inhibitor (PAI-1) and its cell surface receptor (uPAR) have been implicated in a wide variety of biological processes related to tissue homoeostasis. Firstly, the binding of uPA to uPAR favours extracellular proteolysis by enhancing cell surface plasminogen activation. Secondly, it promotes cell adhesion and signalling through binding of the provisional matrix protein vitronectin. We now report that uPA and plasmin induces a potent negative feedback on cell adhesion through specific cleavage of the RGD motif in vitronectin. Cleavage of vitronectin by uPA displays a remarkable receptor dependence and requires concomitant binding of both uPA and vitronectin to uPAR Moreover, we show that PAI-1 counteracts the negative feedback and behaves as a proteolysis-triggered stabilizer of uPAR-mediated cell adhesion to vitronectin. These findings identify a novel and highly specific function for the plasminogen activation system in the regulation of cell adhesion to vitronectin. The cleavage of vitronectin by uPA and plasmin results in the release of N-terminal vitronectin fragments that can be detected in vivo, underscoring the potential physiological relevance of the process.
Topics: Amino Acid Motifs; Cell Adhesion; Cell Line, Tumor; Feedback, Physiological; Fibrinolysin; Fibronectins; Gene Expression; Humans; Plasminogen; Plasminogen Activator Inhibitor 1; Protein Binding; Protein Interaction Domains and Motifs; Proteolysis; Urokinase-Type Plasminogen Activator; Vitronectin
PubMed: 27189837
DOI: 10.15252/embr.201541681 -
FEBS Letters Jan 2003
Topics: Biochemistry; Endopeptidases; History, 20th Century; History, 21st Century; Israel; Periodicals as Topic; Vitronectin
PubMed: 12572567
DOI: 10.1016/s0014-5793(02)03787-0 -
Investigative Ophthalmology & Visual... Dec 2020Vitronectin, a cell adhesion and spreading factor, is suspected to play a role in the pathogenesis of age-related macular degeneration (AMD), as it is a major component...
PURPOSE
Vitronectin, a cell adhesion and spreading factor, is suspected to play a role in the pathogenesis of age-related macular degeneration (AMD), as it is a major component of AMD-specific extracellular deposits (e.g., soft drusen, subretinal drusenoid deposits). The present study addressed the impact of AMD-associated non-synonymous variant rs704 in the vitronectin-encoding gene VTN on vitronectin functionality.
METHODS
Effects of rs704 on vitronectin expression and processing were analyzed by semi-quantitative sequencing of VTN transcripts from retinal pigment epithelium (RPE) cells generated from human induced pluripotent stem cells (hiPSCs) and from human neural retina, as well as by western blot analyses on heterologously expressed vitronectin isoforms. Binding of vitronectin isoforms to retinal and endothelial cells was analyzed by western blot. Immunofluorescence staining followed extracellular matrix (ECM) deposition in cultured RPE cells heterologously expressing the vitronectin isoforms. Adhesion of fluorescently labeled RPE or endothelial cells in dependence of recombinant vitronectin or vitronectin-containing ECM was investigated fluorometrically or microscopically. Tube formation and migration assays addressed effects of vitronectin on angiogenesis-related processes.
RESULTS
Variant rs704 affected expression, secretion, and processing but not oligomerization of vitronectin. Cell binding and influence on RPE-mediated ECM deposition differed between AMD-risk-associated and non-AMD-risk-associated protein isoforms. Finally, vitronectin affected adhesion and endothelial tube formation.
CONCLUSIONS
The AMD-risk-associated vitronectin isoform exhibits increased expression and altered functionality in cellular processes related to the sub-RPE aspects of AMD pathology. Although further research is required to address the subretinal disease aspects, this initial study supports an involvement of vitronectin in AMD pathogenesis.
Topics: Blotting, Western; Cell Encapsulation; Cloning, Molecular; Electrophoresis, Polyacrylamide Gel; Extracellular Matrix; Fluorescent Antibody Technique; Genetic Variation; Human Umbilical Vein Endothelial Cells; Humans; Macular Degeneration; Protein Isoforms; Recombinant Proteins; Retina; Retinal Pigment Epithelium; Vitronectin
PubMed: 33259607
DOI: 10.1167/iovs.61.14.2