Role of Fc receptor γ-chain in platelet glycoprotein Ib–mediated signaling

Wu, Yi; Suzuki‐Inoue, Katsue; Satoh, Kaneo; Asazuma, Naoki; Yatomi, Yutaka; Berndt, Michael C.; Ozaki, Yukio

doi:10.1182/blood.v97.12.3836

Cited by 117 publications

(130 citation statements)

References 53 publications

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“…This leads to binding and phosphorylation of Syk and the ultimate activation of phospholipase C␥2 and other effector molecules. The binding of VWF to the GPIb-IX-V complex has also been shown to result in phosphorylation of FcR␥ (22). Finally, FcR␥ has been observed to physically associate with GPIb␣ after platelet stimulation with alboaggregin A, which binds to both GPIb␣ and GPVI (23).…”

Section: Discussionmentioning

confidence: 94%

“…In fact, studies with other GPIb␣-specific toxins have raised the possibility of a role for FcR␥ in signal transduction initiated by engagement of the GPIb-IX-V complex. The physical proximity of the GPIb-IX-V complex, Fc␥ RIIA, and FcR␥ has been recorded, and there is evidence for functional interrelationships between these molecules (21,22). Cross-linking of the GPIb-IX-V complex and Fc␥ RIIA results in tyrosine phosphorylation of the immunoreceptor tyrosine-based activation motif in both Fc␥ RIIA and FcR␥ (21).…”

Section: Discussionmentioning

confidence: 99%

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Convulxin Binds to Native, Human Glycoprotein Ibα

Kanaji¹,

Kanaji²,

Furihata³

et al. 2003

Journal of Biological Chemistry

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Convulxin (CVX), a C-type snake protein from Crotalus durissus terrificus venom, is the quintessential agonist for studies of the collagen receptor, glycoprotein VI (GPVI) and its role in platelet adhesion to collagens. In this study, CVX, purified from venom, behaves as expected, i.e. it binds to platelet GPVI and recombinant human GPVI, induces platelet aggregation and platelet prothrombinase activity, and binds uniquely to GPVI in ligand blots of SDS-denatured proteins. Nonetheless, we find that CVX has a dual specificity for both GPVI and native but not denatured human GPIb␣. First, CVX binds to human GPIb␣ expressed on the surface of CHO cells. Second, CVX binds weakly to murine platelet GPIb␣ but more strongly to human platelet GPIb␣, as evidenced by comparative binding to wild-type, GPVI(؊/؊), FcR␥ (؊/؊), and human GPIb transgenic mice. Third, the binding of CVX to human GPIb␣ is inhibited by soluble, recombinant human GPVI. Fourth, CVX binding to GPIb␣ is disrupted by phenylalanine substitutions at GPIb␣ tyrosine-276, tyrosine-278, and tyrosine-279, which also disrupts von Willebrand factor and ␣-thrombin binding to GPIb␣. Fifth, CVX binding to GPIb␣ on Chinese hamster ovary cell transfectants is inhibited by function-blocking murine monoclonal anti-GPIb␣ antibodies. Lastly, CVX fails to bind to denatured GPIb␣ in detergent extracts of platelets. Three separate preparations of CVX (two purified by the authors; one obtained commercially) produced equivalent results. These results indicate that CVX exhibits dual specificity for both native GPIb␣ and GPVI. Furthermore, the binding site on GPIb␣ for CVX may be close to that for von Willebrand factor. Therefore, a contribution of GPIb␣ to CVX-induced platelet responses needs to be carefully re-evaluated.Convulxin (CVX) 1 is a 72-kDa protein from Crotalus durissus terrificus venom that has been shown to bind strongly to the platelet-specific collagen receptor, glycoprotein VI (GPVI) (1, 2).The active protein is composed of two disulfide-linked subunits, CVX␣ (13.9 kDa) and CVX␤ (12.6 kDa), which noncovalently assemble into a tridimeric complex (␣ ␤) 3 (3). Both subunits have been cloned and sequenced and exhibit homology with the carbohydrate recognition domain of C-type lectins (4, 5).C-type snake proteins are produced in the venom of numerous true vipers and pit vipers (5). They can be composed of homodimers or heterodimers, often present in multiples, each subunit exhibiting homology to the carbohydrate recognition domain of C-type lectins. Unlike the C-type lectins, however, the subunits of the heterodimeric C-type proteins, such as CVX, do not retain the mannose or galactose recognition sequences and, thus, no longer bind carbohydrate. The ability to bind calcium is retained and may be critical for their activity.A number of the C-type viper venom proteins target platelet receptors, including the glycoprotein Ib (GPIb) complex and GPVI. The majority, including alboaggregin A (6) and alboluxin (7), exhibit dual specificity for these receptors, whereas only...

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Section: Discussionmentioning

confidence: 94%

Section: Discussionmentioning

confidence: 99%

Convulxin Binds to Native, Human Glycoprotein Ibα

Kanaji¹,

Kanaji²,

Furihata³

et al. 2003

Journal of Biological Chemistry

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“…It has also been shown that phosphoinositide (PI) 3-kinase is linked to GPIb-IX-V, via 14-3-3x, and that src kinase is activated by engagement of GPIb-IX-V (1, 2, 26). Additional studies support a role for Fc receptor g-chain (FcRg) in GPIb-IX-Vdependent signalling, since GPIb-IX-V and FcRg are coprecipitated (27), and GPIb-dependent signals are altered in FcRg-deficient platelets (28). FcgRIIa is also associated with GPIb-IX-V (1).…”

Section: Gpib-ix-vmentioning

confidence: 99%

“…Dual receptor occupancy by these ligands could initiate signalling by cross-linking GPIb-IX-V and GPVI (and thus FcRg). Third, both GPIb-IX-V-and GPVI-mediated signaling may involve FcRg (27,28,36,38). FcRg directly associates with GPVI, supporting its surface expression.…”

Section: Co-association Of Gpib-ix-v and Gpvi?mentioning

confidence: 99%

Platelet Interactions in Thrombosis

et al. 2004

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SummaryPatho/physiological platelet aggregate (thrombus) formation is initiated by engagement of platelet surface receptors, glycoprotein (GP)Ib-IX-V and GPVI that bind von Willebrand factor or collagen. Although beneficial in response to vascular injury by preventing blood loss (haemostasis), platelet aggregation in a sclerotic coronary artery or other diseased blood vessel (thrombosis) can cause thrombotic diseases like heart attack and stroke. At the molecular level, ligand interactions with GPIb-IX-V or GPVI trigger signalling responses, including elevation of cytosolic Ca 2 + , dissociation of calmodulin from their cytoplasmic domains, cytoskeletal actin-filament rearrangements, activation of src-family kinases or PI 3-kinase, and 'inside-out' activation of the integrin, aIIbb3 (GPIIb-IIIa), that binds von Willebrand factor or fibrinogen and mediates platelet aggregation. Furthermore, emerging evidence supports a topographical coassociation of these receptors of the leucine-rich repeat family (GPIb-IX-V) and immunoglobulin superfamily (GPVI) in an adhesive cluster or 'adhesosome'. This arrangement may underlie common mechanisms of initiating thrombus formation in haemostasis or thrombotic disease. IUBMB Life, 56: 13-18, 2004

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“…Other receptors coupled to Fc receptors include GPVI, a collagen receptor (Berlanga 2000; GPIb-IX-V, a vWF receptor (Wu 2001, Arthur 2005; and potentially C-type lectin receptor-2 (CLEC-2), which has an as-yet unknown function in platelets (Gross 2006).…”

Section: Immunoglobulin Receptorsmentioning

confidence: 99%

The Tetraspanin CD9 Localizes to Platelet-Platelet Contacts and Regulates Thrombus Stability

Hill¹

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Role of Fc receptor γ-chain in platelet glycoprotein Ib–mediated signaling

Cited by 117 publications

References 53 publications

Convulxin Binds to Native, Human Glycoprotein Ibα

Convulxin Binds to Native, Human Glycoprotein Ibα

Platelet Interactions in Thrombosis

The Tetraspanin CD9 Localizes to Platelet-Platelet Contacts and Regulates Thrombus Stability

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