On the same cell type GPI-anchored normal cellular prion and DAF protein exhibit different biological properties

Abstract

Normal cellular prion protein (PrP C) and decay-accelerating factor (DAF) are glycoproteins linked to the cell surface by glycosylphosphatidylinositol (GPI) anchors. Both PrP C and DAF reside in detergent insoluble complex that can be isolated from human peripheral blood mononuclear cells. However, these two GPI-anchored proteins possess different cell biological properties. The GPI anchor of DAF is markedly more sensitive to cleavage by phosphatidylinositol-specific phospholipase C (PI-PLC) than that of PrP C. Conversely, PrP C has a shorter cell surface half-life than DAF, possibly due to the fact that PrP C but not DAF is shed from the cell surface. This is the first demonstration that on the surface of the same cell type two GPI-anchored proteins differ in their cell biological properties.