NR AIYG
AU Nunziante,M.; Gilch,S.; Schätzl,H.M.
TI Essential role of the prion protein N terminus in subcellular trafficking and half-life of cellular prion protein
QU The Journal of Biological Chemistry 2003 Feb 7; 278(6): 3726-34
PT journal article; research support, non-u.s. gov't
AB Aberrant metabolism and conformational alterations of the cellular prion protein (PrPc) are the underlying causes of transmissible spongiform encephalopathies in humans and animals. In cells, PrPc is modified post-translationally and transported along the secretory pathway to the plasma membrane, where it is attached to the cell surface by a glycosylphosphatidylinositol anchor. In surface biotinylation assays we observed that deletions within the unstructured N terminus of murine PrPc led to a significant reduction of internalization of PrP after transfection of murine neuroblastoma cells. Truncation of the entire N terminus most significantly inhibited internalization of PrPc. The same deletions caused a significant prolongation of cellular half-life of PrPc and a delay in the transport through the secretory pathway to the cell surface. There was no difference in the glycosylation kinetics, indicating that all PrP constructs equally passed endoplasmic reticulum-based cellular quality control. Addition of the N terminus of the Xenopus laevis PrP, which does not encode a copper-binding repeat element, to N-terminally truncated mouse PrP restored the wild type phenotype. These results provide deeper insight into the life cycle of the PrPc, raising the novel possibility of a targeting function of its N-proximal part by interacting with the secretory and the endocytic machinery. They also indicate the conservation of this targeting property in evolution.
MH Animals; Glycosylphosphatidylinositols/metabolism; Half-Life; Kinetics; Mice; Phenotype; PrPc Proteins/chemistry/metabolism/*physiology; Protein Transport; Subcellular Fractions/*metabolism; Tumor Cells, Cultured; Xenopus laevis
AD Gene Center Munich, Max von Pettenkofer Institute for Virology, Faculty of Medicine, Ludwig-Maximilians-University, Feodor-Lynen-Strasse 25, D-81377 Munich, Germany.
SP englisch
PO USA