NR AWNF
AU Sarnataro,D.; Caputo,A.; Casanova,P.; Paladino,S.; Campana,V.; Tivodar,S.; Tacchetti,C.; Zurzolo,C.
TI Both raft-dependent and -independent endocytic pathways mediate PrPc internalization in polarized epithelial FRT cells
QU International Conference - Prion 2006: Strategies, advances and trends towards protection of society - 3.10.-6.10.2006, Torino, Italy, Lingotto Conference Centre - Poster sessions CE-46
PT Konferenz-Poster
AB The cellular prion protein (PrPc) plays a key role in the pathogenesis of Transmissible Spongiform Encephalopathies. In these prion-related diseases PrPc undergoes post-translational conversion to the infectious form (PrPsc). Although PrPc is known to be located in detergent-resistant membrane domains (DRMs or rafts) in both epithelial and neuronal cells, the mechanism underlying its internalization is still debated, as caveolae and clathrin-dependent processes have been described to be involved in different cell types. By combining morphological and biochemical assays we have investigated the mechanism of PrPc endocytosis in FRT cells, which lack caveolin-1 and caveolae, and in FRT-cav1 cells which possess caveolin and caveolae. We found that in FRT cells PrPc is internalized through smooth vesicular invaginations from the plasma membrane. PrP internalization is affected by cholesterol depletion and requires activated Cdc-42, which was previously shown to be involved in raft-mediated internalization of GPI-anchored proteins. In addition, we found that PrPc endocytosis is also regulated by Eps15-Ap2 binding and dynamin 2, suggesting an involvement of a clathrin-dependent pathway. By using FRT-cav1 cells we also show that, although PrPc resides in caveolae at steady state, caveolae do not participate to its internalization. In conclusion our data indicate that both a raft-dependent and a raft-independent pathway, but not caveolae, have a mutual non exclusive role in PrPc internalization.
AD D. Sarnataro, A. Caputo, S. Tivodar: Unité postulante de Trafic Membranaire et Pathogenese, Institut Pasteur, Paris France; P. Casanova, V. Campana: Dipartimento di Biologia e Patologia Cellulare e Molecolare Univesità Federico II, Napoli, Italy; S. Paladino: Unité postulante de Trafic Membranaire et Pathogenese, Institut Pasteur, Paris France, and CEINGE, Napoli Italy; C. Tacchetti: University of Genova, Medical School, Genova, Italy; C. Zurzolo: Unité postulante de Trafic Membranaire et Pathogenese, Institut Pasteur, Paris France, and Dipartimento di Biologia e Patologia Cellulare e Molecolare Univesità Federico II, Napoli, Italy
SP englisch
PO Italien