The distribution of glycosyl-phosphatidylinositol anchored proteins is differentially regulated by serum and insulin.

Glycosyl-phosphatidylinositol (GPI) anchored proteins are surveyed in two insulin sensitive cell types by surface labeling and phospholipase C-induced release into the medium. Serum starvation selectively increases both the number and intensity of a subset of GPI-anchored proteins. After serum starvation, loss of cell-surface GPI-anchored proteins is induced acutely by either serum re-exposure or insulin, suggesting that hormonal treatment may promote the release of these proteins from the cell surface.