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Endocytic Intermediates Involved With The Intracellular Trafficking Of A Fluorescent Cellular Prion Protein, Ac Magalhaes, Ja Silva, Vr Martins, Vf Prado, Ssg Ferguson, Mv Gomez, Rr Brentani, Mam Prado

Anatomy and Cell Biology Publications

We have investigated the intracellular traffic of PrPc, a glycosylphosphatidylinositol (GPI)-anchored protein implicated in spongiform encephalopathies. A fluorescent functional green fluorescent protein (GFP)-tagged version of PrPc is found at the cell surface and in intracellular compartments in SN56 cells. Confocal microscopy and organelle-specific markers suggest that the protein is found in both the Golgi and the recycling endosomal compartment. Perturbation of endocytosis with a dynamin I-K44A dominant-negative mutant altered the steady-state distribution of the GFP-PrPc, leading to the accumulation of fluorescence in unfissioned endocytic intermediates. These pre-endocytic intermediates did not seem to accumulate GFP-GPI, a minimum GPI-anchored protein, suggesting that …