The phytotoxin fusicoccin promotes platelet aggregation via 14-3-3/Glycoprotein Ib-IX-V interaction

Lorenzo Camoni (1) , Cristina Di Lucente , Sabina Visconti , Patrizia Aducci

1 Department of Biology

The fungal toxin fusicoccin induces plant wilting by affecting ion transport across the plasma membrane of plant cell. The activity of this toxin is so far unknown in humans. Here we show that fusicoccin is able to affect the platelet aggregation process. The toxin associates to platelet intracellular binding sites and induces aggregation in platelet-rich plasma in a dose-dependent manner. We identified the adhesion receptor glycoprotein Ib-IX-V as fusicoccin target. The toxin promotes the binding of the regulatory 14-3-3 proteins to glycoprotein Ibα and hampers that to glycoprotein Ibβ subunit. As a result, platelet adhesion to von Willebrand Factor is stimulated, leading to platelet spreading and integrin αIIbβ3 activation. We anticipate our study to be a starting point for future therapeutic use of fusicoccin in genetic bleeding diseases characterized by qualitative or quantitative abnormalities of the platelet membrane adhesion receptors. Furthermore, the present study also sets the stage for future work to determine the potential pharmacological application of fusicoccin as a drug directed to other 14-3-3/target complexes.

Mots clés: Life Sciences

Lorenzo Camoni, Cristina Di Lucente, Sabina Visconti, Patrizia Aducci. The phytotoxin fusicoccin promotes platelet aggregation via 14-3-3/Glycoprotein Ib-IX-V interaction. Biochemical Journal, 2011, 436 (2), pp.429-436. ⟨10.1042/BJ20102037⟩. ⟨hal-00592576⟩