Ubiquitin-proteasome system has emerged a central player in regulation of diverse cellular
processes. However, relevance of proteasome activity in platelets, which are terminally
differentiated enucleate cells, is not clear. In this report we show that activation of platelets
with physiological agonists was associated with 7–10-fold rise in proteasomal activity.
Elevation of cytosolic calcium with A23187 or thapsigargin resulted in significant increase in
enzymatic activity, while treatment with intracellular calcium chelator or inhibitor of inositol …