The snake venom toxin alboaggregin-A activates glycoprotein VI

Abstract

The glycoprotein (GP)-lb-IX-V receptor complex has recently been reported to signal through a pathway similar to that used by the collagen receptor GPVI, with a critical role described for the Fc receptor γ-chain. The evidence for this was based in part on studies with the GPlbα-selective snake venom toxin, alboaggregin-A. In the present study, it is reported that alboaggregin-A has activity at the Collagen receptor GPVI in addition to GPlbα, and evidence is provided that this contributes to protein tyrosine phosphorylation, shape change, and GPlb-llla-dependent aggregation. This may explain why responses to alboaggregin-A are distinct from those to von Willebrand factor-ristocetin. © 2001 by The American Society of Hematology.