NR ALCV
AU Stahl,N.; Borchelt,D.R.; Hsiao,K.; Prusiner,S.B.
TI Scrapie prion protein contains a phosphatidylinositol glycolipid
QU Cell 1987 Oct 23; 51(2): 229-40
PT journal article
AB The scrapie (PrPsc) and cellular (PrPc) prion proteins are encoded by the same gene, and their different properties are thought to arise from posttranslational modifications. We have found a phosphatidylinositol glycolipid on both PrPc and PrP 27-30 (derived from PrPsc by limited proteolysis at the amino terminus). Ethanolamine, myo-inositol, phosphate, and stearic acid were identified as glycolipid components of gel-purified PrP 27-30. PrP 27-30 contains 2.8 moles of ethanolamine per mole. Incubation of PrP 27-30 with a bacterial phosphatidylinositol-specific phospholipase C (PIPLC) releases covalently bound stearic acid, and allows PrP 27-30 to react with antiserum specific for the PIPLC-digested glycolipid linked to the carboxyl terminus of the trypanosomal variant surface glycoprotein. PIPLC catalyzes the release of PrPc from cultured mammalian cells into the medium. These observations indicate that PrPc is anchored to the cell surface by the glycolipid.
IN Normales zelluläres und auch das gegenüber Proteinase K relativ resistente und deshalb beim Proteinase-K-Verdau Scrapie-infizierten Gewebes entstehende Prionproteinfragment PrP 27-30, sind beide an ein Phosphatidylinositolglycolipid gebunden. Die Glycolipid-Komponente kann Ethanolamin, Myoinositol, oder Stearinsäure sein. Dabei scheinen an 1 Mol Prionproteine etwa 2,8 Mol Ethanolamin gebunden zu sein. Mit der bakteriellen Phosphatidylinositol-spezifischen Phospholipase C löst die Verankerung und entläßt das normale zelluläre Prionprotein ins Medium. Das normale Prionprotein muß daher auf der Membranaußenseite durch einen Phosphatidylinositolglycolipid-Anker gebunden sein.
MH Animal; Cell Membrane/metabolism; Chromatography, High Pressure Liquid; Cross Reactions; Epitopes; Fatty Acids/metabolism; Glycolipids/*metabolism; Hydrolysis; Immune Sera/immunology; Mass Fragmentography; Phosphatidylinositols/*metabolism; Phospholipase C/metabolism; Prions/*metabolism; Protein Processing, Post-Translational; Proteins/metabolism; Spectrum Analysis, Mass; Support, Non-U.S. Gov't; Support, U.S. Gov't, P.H.S.
AD Department of Neurology, University of California, San Francisco 94143.
SP englisch
PO USA
ZF kritische Zusammenfassung von Roland Heynkes