Gelsolin controls the release of phosphatidylserine (PS)-positive microvesicles (MVs) from platelets.

Upon activation by vascular injury or extracellular agonists, platelets undergo rapid change shape, a process regulated by the actin cytoskeleton and accessory proteins. Platelet shape change is accompanied by the secretion of hemostatic factors and immunomodulatory cytokines from their intracellular granules, as well as the release of microvesicles (MVs) containing pro-inflammatory cytokines and procoagulant phosphatidylserine (PS). However, the role of actin dynamics in MV generation remains unclear.

Gelsolin regulates receptor-mediated and fluid-phase endocytosis in platelets.

Background: Endocytosis is the process by which platelets incorporate extracellular molecules into their secretory granules. Endocytosis is mediated by the actin cytoskeleton in nucleated cells; however, the endocytic mechanisms in platelets are undefined.

Objectives: To better understand platelet endocytosis, we studied gelsolin (Gsn), an actin-severing protein that promotes actin assembly.

PACSIN2 regulates platelet integrin β1 hemostatic function.

Background: Upon vessel injury, platelets adhere to exposed matrix constituents via specific membrane receptors, including the von Willebrand factor receptor glycoprotein (GP)Ib-IX-V complex and integrins β1 and β3. In platelets, the Fes/CIP4-homology Bin-Amphiphysin-Rvs protein PACSIN2 associates with the cytoskeletal and scaffolding protein filamin A (FlnA), linking GPIbα and integrins to the cytoskeleton.

Objectives: Here we investigated the role of PACSIN2 in platelet function.