scholarly journals Atroxlysin-III, A Metalloproteinase from the Venom of the Peruvian Pit Viper Snake Bothrops atrox (Jergón) Induces Glycoprotein VI Shedding and Impairs Platelet Function

Molecules ◽  
2019 ◽  
Vol 24 (19) ◽  
pp. 3489 ◽  
Author(s):  
Luciana S. Oliveira ◽  
Maria Inácia Estevão-Costa ◽  
Valéria G. Alvarenga ◽  
Dan E. Vivas-Ruiz ◽  
Armando Yarleque ◽  
...  
Keyword(s):  
Metal Ion ◽  
Type I Collagen ◽  
Divalent Cations ◽  
Type I ◽  
Glycoprotein Vi ◽  
Rich Domain ◽  
Multidomain Structure ◽  
A1 Domain ◽  
Bothrops Atrox ◽  
Α2β1 Integrin

Atroxlysin-III (Atr-III) was purified from the venom of Bothrops atrox. This 56-kDa protein bears N-linked glycoconjugates and is a P-III hemorrhagic metalloproteinase. Its cDNA-deduced amino acid sequence reveals a multidomain structure including a proprotein, a metalloproteinase, a disintegrin-like and a cysteine-rich domain. Its identity with bothropasin and jararhagin from Bothrops jararaca is 97% and 95%, respectively. Its enzymatic activity is metal ion-dependent. The divalent cations, Mg2+ and Ca2+, enhance its activity, whereas excess Zn2+ inhibits it. Chemical modification of the Zn2+-complexing histidine residues within the active site by using diethylpyrocarbonate (DEPC) inactivates it. Atr-III degrades plasma fibronectin, type I-collagen, and mainly the α-chains of fibrinogen and fibrin. The von Willebrand factor (vWF) A1-domain, which harbors the binding site for GPIb, is not hydrolyzed. Platelets interact with collagen via receptors for collagen, glycoprotein VI (GPVI), and α2β1 integrin. Neither the α2β1 integrin nor its collagen-binding A-domain is fragmented by Atr-III. In contrast, Atr-III cleaves glycoprotein VI (GPVI) into a soluble ~55-kDa fragment (sGPVI). Thereby, it inhibits aggregation of platelets which had been stimulated by convulxin, a GPVI agonist. Selectively, Atr-III targets GPVI antagonistically and thus contributes to the antithrombotic effect of envenomation by Bothrops atrox.

scholarly journals Monkey Rotavirus Binding to α2β1 Integrin Requires the α2 I Domain and Is Facilitated by the Homologous β1 Subunit

2003 ◽  
Vol 77 (17) ◽  
pp. 9486-9501 ◽  
Author(s):  
Sarah L. Londrigan ◽  
Kate L. Graham ◽  
Yoshikazu Takada ◽  
Peter Halasz ◽  
Barbara S. Coulson
Keyword(s):  
Metal Ion ◽  
Type I Collagen ◽  
Surface Proteins ◽  
Type I ◽  
Integrin Subunit ◽  
Amino Acid Residues ◽  
Cho Cell ◽  
Human Rotavirus ◽  
Α2β1 Integrin

ABSTRACT Rotaviruses utilize integrins during virus-cell interactions that lead to infection. Cell binding and infection by simian rotavirus SA11 were inhibited by antibodies (Abs) to the inserted (I) domain of the α2 integrin subunit. To determine directly which integrins or other proteins bind rotaviruses, cell surface proteins precipitated by rotaviruses were compared with those precipitated by anti-α2β1 Abs. Two proteins precipitated by SA11 and rhesus rotavirus RRV from MA104 and Caco-2 cells migrated indistinguishably from α2β1 integrin, and SA11 precipitated β1 from α2β1-transfected CHO cells. These viruses specifically precipitated two MA104 cell proteins only, but an additional 160- to 165-kDa protein was precipitated by SA11 from Caco-2 cells. The role of the α2 I domain in rotavirus binding, infection, and growth was examined using CHO cell lines expressing wild-type or mutated human α2 or α2β1. Infectious SA11 and RRV, but not human rotavirus Wa, specifically bound CHO cell-expressed human α2β1 and, to a lesser extent, human α2 combined with hamster β1. Binding was inhibited by anti-α2 I domain monoclonal Abs (MAbs), but not by non-I domain MAbs to α2, and required the presence of the α2 I domain. Amino acid residues 151, 221, and 254 in the metal ion-dependent adhesion site of the α2 I domain that are necessary for type I collagen binding to α2β1 were not essential for rotavirus binding. Rotavirus-α2β1 binding led to increased virus infection and RRV growth. SA11 and RRV require the α2 I domain for binding to α2β1, and their binding to this integrin is distinguishable from that of collagen.

Fibrillar type I collagens enhance platelet-dependent thrombin generation via glycoprotein VI with direct support of α2β1 but not αIIbβ3 integrin

2005 ◽  
Vol 94 (07) ◽  
pp. 107-114 ◽  
Author(s):  
Christelle Lecut ◽  
Martine Jandrot-Perrus ◽  
Marion A. H. Feijge ◽  
Judith M. E. M. Cosemans ◽  
Johan W. M. Heemskerk
Keyword(s):  
Thrombin Generation ◽  
Type I Collagen ◽  
Platelet Rich Plasma ◽  
Procoagulant Activity ◽  
Type I ◽  
Platelet Surface ◽  
Glycoprotein Vi ◽  
Collagen Receptors ◽  
Fibrillar Collagens

SummaryThe role of collagens and collagen receptors was investigated in stimulating platelet-dependent thrombin generation. Fibrillar type-I collagens, including collagen from human heart, were most potent in enhancing thrombin generation, in a way dependent on exposure of phosphatidylserine (PS) at the platelet surface. Soluble, non-fibrillar type-I collagen required pre-activation of integrin α2β1 with Mn2+ for enhancement of thrombin generation. With all preparations, blocking of glycoprotein VI (GPVI) with 9O12 antibody abrogated the collagen-enhanced thrombin generation, regardless of the α2β1 activation state. Blockade of α2β1 alone or antagonism of autocrine thromboxane A2 and ADP were less effective. Blockade of αIIbβ3 with abciximab suppressed thrombin generation in platelet-rich plasma, but this did not abolish the enhancing effect of collagens. The high activity of type-I fibrillar collagens in stimulating GPVI-dependent procoagulant activity was confirmed in whole-blood flow studies, showing that these collagens induced relatively high expression of PS. Together, these results indicate that: i) fibrillar type-I collagen greatly enhances thrombin generation, ii) GPVI-induced platelet activation is principally responsible for the procoagulant activity of fibrillar and non-fibrillar collagens, iii) α2β1 and signaling via autocrine mediators facilitate and amplify this GPVI activity, and iv) αIIbβ3 is not directly involved in the collagen effect.

Dual role of collagen in factor XII–dependent thrombus formation

Blood ◽  
2009 ◽  
Vol 114 (4) ◽  
pp. 881-890 ◽  
Author(s):  
Paola E. J. van der Meijden ◽  
Imke C. A. Munnix ◽  
Jocelyn M. Auger ◽  
José W. P. Govers-Riemslag ◽  
Judith M. E. M. Cosemans ◽  
...  
Keyword(s):  
Thrombin Generation ◽  
Type I Collagen ◽  
Factor Viia ◽  
Thrombus Formation ◽  
Dual Role ◽  
Type I ◽  
Factor Xii ◽  
Glycoprotein Vi

Abstract In vivo mouse models have indicated that the intrinsic coagulation pathway, initiated by factor XII, contributes to thrombus formation in response to major vascular damage. Here, we show that fibrillar type I collagen provoked a dose-dependent shortening of the clotting time of human plasma via activation of factor XII. This activation was mediated by factor XII binding to collagen. Factor XII activation also contributed to the stimulating effect of collagen on thrombin generation in plasma, and increased the effect of platelets via glycoprotein VI activation. Furthermore, in flow-dependent thrombus formation under coagulant conditions, collagen promoted the appearance of phosphatidylserine-exposing platelets and the formation of fibrin. Defective glycoprotein VI signaling (with platelets deficient in LAT or phospholipase Cγ2) delayed and suppressed phosphatidylserine exposure and thrombus formation. Markedly, these processes were also suppressed by absence of factor XII or XI, whereas blocking of tissue factor/factor VIIa was of little effect. Together, these results point to a dual role of collagen in thrombus formation: stimulation of glycoprotein VI signaling via LAT and PLCγ2 to form procoagulant platelets; and activation of factor XII to stimulate thrombin generation and potentiate the formation of platelet-fibrin thrombi.

Function of Glycoprotein VI and Integrin α2β1 in the Procoagulant Response of Single, Collagen-Adherent Platelets

1999 ◽  
Vol 81 (05) ◽  
pp. 782-792 ◽  
Author(s):  
Pia Siljander ◽  
Wim Vuist ◽  
Githa Breikers ◽  
Chris Reutelingsperger ◽  
Michael Barnes ◽  
...  
Keyword(s):  
Type I Collagen ◽  
Type I ◽  
Dependent Manner ◽  
Fibrillar Collagen ◽  
Structural Requirements ◽  
Glycoprotein Vi ◽  
Related Peptide ◽  
Collagen Receptors ◽  
Membrane Blebs ◽  
Bleb Formation

SummaryVarious collagen-based materials were used to assess the structural requirements of collagen for inducing the procoagulant response of adhering platelets, as well as the collagen receptors involved. Cross-linked or monomeric collagen-related peptide (CRP), Gly-Cys-Hyp-(Gly-Pro-Hyp)10-Gly-Cys-Hyp-Gly was highly adhesive for platelets in a glycoprotein VI- (GpVI-)dependent manner. Adhesion was followed by a prolonged increase in cytosolic [Ca2+]i, formation of membrane blebs, exposure of phosphatidylserine (PS) and generation of prothrombinase-stimulating activity. Fibrils of type-I collagen were less adhesive but, once adhered, many of the platelets presented a full procoagulant response. Monomeric type-I collagen was unable to support adhesion, unless Mg2+-dependent integrin α2β1 interactions were facilitated by omission of Ca2+ ions. With all surfaces, however, post-addition of CaCl2 to adhering platelets resulted in a potent Ca2+-influx signal, followed by PS exposure and bleb formation. The procoagulant response elicited by binding to CRP was inhibited by anti-GpVI Fab fragments, but not by impeding integrin α2β1-mediated events. With fibrillar collagen, it was inhibited by blocking either the GpVI- or integrin α2β1- mediated interactions. This suggests that the triple-helical Gly-Pro-Hyp repeat in CRP and analogous sequences in fibrillar collagen stimulate the procoagulant response of adherent platelets by acting as ligands for GpVI. Influx of Ca2+ is required for this response, and adhesion via integrin α2β1 serves to potentiate the signaling effects of GpVI.

scholarly journals Discoidin Domain Receptor 1 Protein Is a Novel Modulator of Megakaryocyte-Collagen Interactions

2013 ◽  
Vol 288 (23) ◽  
pp. 16738-16746 ◽  
Author(s):  
Vittorio Abbonante ◽  
Cristian Gruppi ◽  
Diana Rubel ◽  
Oliver Gross ◽  
Remigio Moratti ◽  
...  
Keyword(s):  
Type I Collagen ◽  
Type I ◽  
Discoidin Domain Receptor ◽  
Glycoprotein Vi ◽  
Protein Levels ◽  
Collagen Receptors ◽  
And Function ◽  
Extracellular Matrix Receptors ◽  
Collagen Receptor ◽  
Discoidin Domain Receptor 1

Growing evidence demonstrates that extracellular matrices regulate many aspects of megakaryocyte (MK) development; however, among the different extracellular matrix receptors, integrin α2β1 and glycoprotein VI are the only collagen receptors studied in platelets and MKs. In this study, we demonstrate the expression of the novel collagen receptor discoidin domain receptor 1 (DDR1) by human MKs at both mRNA and protein levels and provide evidence of DDR1 involvement in the regulation of MK motility on type I collagen through a mechanism based on the activity of SHP1 phosphatase and spleen tyrosine kinase (Syk). Specifically, we demonstrated that inhibition of DDR1 binding to type I collagen, preserving the engagement of the other collagen receptors, glycoprotein VI, α2β1, and LAIR-1, determines a decrease in MK migration due to the reduction in SHP1 phosphatase activity and consequent increase in the phosphorylation level of its main substrate Syk. Consistently, inhibition of Syk activity restored MK migration on type I collagen. In conclusion, we report the expression and function of a novel collagen receptor on human MKs, and we point out that an increasing level of complexity is necessary to better understand MK-collagen interactions in the bone marrow environment.

Metastatic Dissemination of Human Ovarian Epithelial Carcinoma Is Promoted by α2β1-Integrin-Mediated Interaction with Type I Collagen

1998 ◽  
Vol 18 (1) ◽  
pp. 15-26 ◽  
Author(s):  
David A. Fishman ◽  
Alicia Kearns ◽  
Krishna Chilukuri ◽  
Lisa M. Bafetti ◽  
Edel A. O’Toole ◽  
...  
Keyword(s):  
Type I Collagen ◽  
Type I ◽  
Metastatic Dissemination ◽  
Ovarian Epithelial Carcinoma ◽  
Α2β1 Integrin

Platelet α2β1 integrin activation: contribution of ligand internalization and the α2-cytoplasmic domain

Blood ◽  
2003 ◽  
Vol 102 (4) ◽  
pp. 1307-1315 ◽  
Author(s):  
Zhengyan Wang ◽  
Tina M. Leisner ◽  
Leslie V. Parise
Keyword(s):  
Type I Collagen ◽  
Cytoplasmic Tail ◽  
Fluorescein Isothiocyanate ◽  
Activation Process ◽  
Type I ◽  
Collagen Binding ◽  
Cell Permeable Peptide ◽  
A Cell ◽  
Collagen Receptor ◽  
Α2β1 Integrin

Abstract The α2β1 integrin is a major collagen receptor on platelets. Although it has been proposed that α2β1, like αIIbβ3, undergoes agonist-induced activation, neither the potential contributions of α2β1 receptor/ligand internalization to the increase in ligand binding nor the roles of the α2 and β1 cytoplasmic domains in activation of this integrin have been previously explored. Activation of α2β1 was assessed with fluorescein isothiocyanate–labeled soluble type I collagen binding to platelets by flow cytometry. Although collagen internalization in response to agonist activation of platelets was significant, agonist-induced collagen binding still occurred under conditions that block internalization, with minimal changes in cell surface α2β1 expression. Introduction of cell-permeable peptides containing the α2 cytoplasmic tail, and especially the membrane proximal KLGFFKR domain, induced α2β1 activation in resting platelets, whereas a cell-permeable peptide containing the β1 cytoplasmic tail was without effect. Thus, collagen binding to stimulated platelets is increased due to α2β1 activation, in addition to internalization, and the GFFKR motif appears to play an important role in the activation process.

scholarly journals Crosstalk between the α2β1 integrin and c-met/HGF-R regulates innate immunity

Blood ◽  
2008 ◽  
Vol 111 (7) ◽  
pp. 3562-3570 ◽  
Author(s):  
Karissa D. McCall-Culbreath ◽  
Zhengzhi Li ◽  
Mary M. Zutter
Keyword(s):  
Immune Response ◽  
Innate Immunity ◽  
Innate Immune Response ◽  
Cell Activation ◽  
Type I Collagen ◽  
Innate Immune ◽  
Mast Cell Activation ◽  
Type I ◽  
Matrix Metalloproteinase 1 ◽  
Α2β1 Integrin

AbstractData from several investigators suggest that the α2β1 integrin, a receptor for collagens, laminins, decorin, E-cadherin, matrix metalloproteinase-1, endorepellin, and several viruses, is required for innate immunity and regulation of autoimmune/allergic disorders. We demonstrated that the innate immune response to Listeria monocytogenes required α2β1 integrin expression by peritoneal mast cells (PMCs). Ligation of the α2β1 integrin by C1q contained in immune complexes comprised of Listeria and antibody was required for PMC activation in vitro and in vivo. However, ligation of the α2β1 integrin alone was insufficient to activate cytokine secretion, suggesting that one or more additional signals emanating from a coreceptor were required for PMC activation. Here, we demonstrate that C1q, but neither other complement proteins nor FcRγ, is required for early innate immune response to Listeria. The binding of Listeria's Internalin B (InlB) to hepatocyte growth factor receptor (HGF-R)/c-met provides the costimulatory function required for PMC activation. Either HGF or Listeria InlB bound to c-met and either C1q or type I collagen bound to α2β1 integrin stimulates PMC activation. These findings suggest that crosstalk between c-met and the α2β1 integrin may contribute to mast-cell activation in autoimmune and inflammatory disorders.

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