Upon activation, platelets release many active substances stored in α- and dense-core granules. However, the molecular mechanisms governing the regulated exocytosis are not yet fully understood. We have established an assay system using streptolysin-O-permeabilized platelets to analyze the Ca2+-induced secretions of von Willebrand factor stored in α-granules and [3H]5-hydroxytryptamine (5-HT) in dense-core granules. Using the assay, we found that small GTPase Rab4 regulates α-, but not dense-core, granule secretion in platelets. Furthermore, we purified a cytosolic essential protein and currently are analyzing its function.
|Number of pages||4|
|Journal||Annals of the New York Academy of Sciences|
|Publication status||Published - 2001|
- Dense-core granules
- Molecular dissection
- Platelet secretion