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Identification and characterization of a collagen‐induced platelet aggregation inhibitor, triplatin, from salivary glands of the assassin bug, Triatoma infestans
Author(s) -
Morita Akihiro,
Isawa Haruhiko,
Orito Yuki,
Iwanaga Shiroh,
Chinzei Yasuo,
Yuda Masao
Publication year - 2006
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/j.1742-4658.2006.05306.x
Subject(s) - gpvi , platelet , triatoma infestans , chemistry , microbiology and biotechnology , receptor , thrombin , biochemistry , collagen receptor , saliva , integrin , biology , immunology , trypanosoma cruzi , parasite hosting , world wide web , computer science
To facilitate feeding, certain hematophagous invertebrates possess inhibitors of collagen‐induced platelet aggregation in their saliva. However, their mechanisms of action have not been fully elucidated. Here, we describe two major salivary proteins, triplatin‐1 and ‐2, from the assassin bug, Triatoma infestans , which inhibited platelet aggregation induced by collagen but not by other agents including ADP, arachidonic acid, U46619 and thrombin. Furthermore, these triplatins also inhibited platelet aggregation induced by collagen‐related peptide, a specific agonist of the major collagen‐signaling receptor glycoprotein (GP)VI. Moreover, triplatin‐1 inhibited Fc receptor γ‐chain phosphorylation induced by collagen, which is the first step of GPVI‐mediated signaling. These results strongly suggest that triplatins target GPVI and inhibit signal transduction necessary for platelet activation by collagen. This is the first report on the mechanism of action of collagen‐induced platelet aggregation inhibitors from hematophagus invertebrates.