NR AHEH
AU Lehmann,S.; Harris,D.A.
TI A mutant prion protein displays an aberrant membrane association when expressed in cultured cells
QU The Journal of Biological Chemistry 1995 Oct 13; 270(41): 24589-97
ER J Biol Chem 2000 Jan 14;275(2):1520
PT journal article
AB Inherited forms of prion disease have been linked to mutations in the gene encoding PrP, a neuronal and glial protein that is attached to the plasma membrane by a glycosyl-phosphatidylinositol (GPI) anchor. One familial form of Creutzfeldt-Jakob disease is associated with a mutant PrP containing six additional octapeptide repeats. We report here our analysis of cultured Chinese hamster ovary cells expressing a murine homologue of this mutant PrP. We find that, like wild-type PrP, the mutant protein is glycosylated, GPI-anchored, and expressed on the cell surface. Surprisingly, however, cleavage of the GPI anchor using phosphatidylinositol-specific phospholipase C fails to release the mutant PrP from the surface of intact cells, suggesting that it has an additional mode of membrane attachment. The phospholipase-treated protein is hydrophobic, since it partitions into the detergent phase of Triton X-114 lysates; and it is tightly membrane-associated, since it is not extractable in carbonate buffer at pH 11.5. Whether membrane attachment of the mutant PrP involves integration of the polypeptide into the lipid bilayer, self-association, or binding to other membrane proteins remains to be determined. Our results suggest that alterations in the membrane association of PrP may be an important feature of prion diseases.
MH Amino Acid Sequence; Animal; Antibodies; Base Sequence; CHO Cells; Cell Membrane/metabolism; Comparative Study; Creutzfeldt-Jakob Syndrome/*genetics; DNA Primers; Glycosylation; Glycosylphosphatidylinositols/metabolism; Hamsters; Human; Lipid Bilayers; Mice; Molecular Sequence Data; Mutagenesis; *Mutation; Peptide Fragments/chemical synthesis/chemistry/immunology; Phosphoric Diester Hydrolases/pharmacology; Polymerase Chain Reaction; Prions/*biosynthesis/*genetics/isolation & purification; Recombinant Proteins/biosynthesis/isolation & purification; Support, Non-U.S. Gov't; Transfection
AD Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
SP englisch
PO USA
OR Prion-Krankheiten L