Increased cell surface exposure of fucose residues is a late event in apoptosis

Apoptosis is a well defined physiological process characterised by many specific features including DNA fragmentation and protease activation. Cell membrane-associated changes such as the altered exposure of phosphatidylserine and glycosylation patterns have also been described. We investigate here the change in exposure of surface alpha-L-fucose residues during thymocyte and P815 cell apoptosis. We show that apoptosis in these cells induced by dexamethasone, gliotoxin or thapsigargin was associated with an increase in the exposure of terminal fucose residues. Furthermore, this increase in fucose exposure occurred late in the apoptotic process. The observation of increased fucose exposure in two different cell types by three different apoptosis-inducing agents suggests it may be part of the normal apoptotic process.