Abstract
Background: The cellular prion protein (PrPC) plays a key role in the pathogenesis of Transmissible Spongiform Encephalopathies in which the protein undergoes post-translational conversion to the infectious form (PrPSc). Although endocytosis appears to be required for this conversion, the mechanism of PrPC internalization is still debated, as caveolae/raft- and clathrin-dependent processes have all been reported to be involved. Methodology/Principal Findings: We have investigated the mechanism of PrPC endocytosis in Fischer Rat Thyroid (FRT) cells, which lack caveolin-1 (cav-1) and caveolae, and in FRT/cav-1 cells which form functional caveolae. We show that PrPC internalization requires activated Cdc-42 and is sensitive to cholesterol depletion but not to cav-1 expression suggesting a role for rafts but not for caveolae in PrPC endocytosis. PrPC internalization is also affected by knock down of clathrin and by the expression of dominant negative Eps15 and Dynamin 2 mutants, indicating the involvement of a clathrin-dependent pathway. Notably, PrPC co-immunoprecipitates with clathrin and remains associated with detergent-insoluble microdomains during internalization thus indicating that PrPC can enter the cell via multiple pathways and that rafts and clathrin cooperate in its internalization. Conclusions/Significance: These findings are of particular interest if we consider that the internalization route/s undertaken by PrPC can be crucial for the ability of different prion strains to infect and to replicate in different cell lines.
| Original language | English |
|---|---|
| Article number | e5829 |
| Journal | PLoS One |
| Volume | 4 |
| Issue number | 6 |
| DOIs | |
| Publication status | Published - Jun 8 2009 |
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ASJC Scopus subject areas
- Agricultural and Biological Sciences(all)
- Biochemistry, Genetics and Molecular Biology(all)
- Medicine(all)
Cite this
Lipid rafts and clathrin cooperate in the internalization of PrPC in epithelial FRT cells. / Sarnataro, Daniela; Caputo, Anna; Casanova, Philippe; Puri, Claudia; Paladino, Simona; Tivodar, Simona S.; Campana, Vincenza; Tacchetti, Carlo; Zurzolo, Chiara.
In: PLoS One, Vol. 4, No. 6, e5829, 08.06.2009.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Lipid rafts and clathrin cooperate in the internalization of PrPC in epithelial FRT cells
AU - Sarnataro, Daniela
AU - Caputo, Anna
AU - Casanova, Philippe
AU - Puri, Claudia
AU - Paladino, Simona
AU - Tivodar, Simona S.
AU - Campana, Vincenza
AU - Tacchetti, Carlo
AU - Zurzolo, Chiara
PY - 2009/6/8
Y1 - 2009/6/8
N2 - Background: The cellular prion protein (PrPC) plays a key role in the pathogenesis of Transmissible Spongiform Encephalopathies in which the protein undergoes post-translational conversion to the infectious form (PrPSc). Although endocytosis appears to be required for this conversion, the mechanism of PrPC internalization is still debated, as caveolae/raft- and clathrin-dependent processes have all been reported to be involved. Methodology/Principal Findings: We have investigated the mechanism of PrPC endocytosis in Fischer Rat Thyroid (FRT) cells, which lack caveolin-1 (cav-1) and caveolae, and in FRT/cav-1 cells which form functional caveolae. We show that PrPC internalization requires activated Cdc-42 and is sensitive to cholesterol depletion but not to cav-1 expression suggesting a role for rafts but not for caveolae in PrPC endocytosis. PrPC internalization is also affected by knock down of clathrin and by the expression of dominant negative Eps15 and Dynamin 2 mutants, indicating the involvement of a clathrin-dependent pathway. Notably, PrPC co-immunoprecipitates with clathrin and remains associated with detergent-insoluble microdomains during internalization thus indicating that PrPC can enter the cell via multiple pathways and that rafts and clathrin cooperate in its internalization. Conclusions/Significance: These findings are of particular interest if we consider that the internalization route/s undertaken by PrPC can be crucial for the ability of different prion strains to infect and to replicate in different cell lines.
AB - Background: The cellular prion protein (PrPC) plays a key role in the pathogenesis of Transmissible Spongiform Encephalopathies in which the protein undergoes post-translational conversion to the infectious form (PrPSc). Although endocytosis appears to be required for this conversion, the mechanism of PrPC internalization is still debated, as caveolae/raft- and clathrin-dependent processes have all been reported to be involved. Methodology/Principal Findings: We have investigated the mechanism of PrPC endocytosis in Fischer Rat Thyroid (FRT) cells, which lack caveolin-1 (cav-1) and caveolae, and in FRT/cav-1 cells which form functional caveolae. We show that PrPC internalization requires activated Cdc-42 and is sensitive to cholesterol depletion but not to cav-1 expression suggesting a role for rafts but not for caveolae in PrPC endocytosis. PrPC internalization is also affected by knock down of clathrin and by the expression of dominant negative Eps15 and Dynamin 2 mutants, indicating the involvement of a clathrin-dependent pathway. Notably, PrPC co-immunoprecipitates with clathrin and remains associated with detergent-insoluble microdomains during internalization thus indicating that PrPC can enter the cell via multiple pathways and that rafts and clathrin cooperate in its internalization. Conclusions/Significance: These findings are of particular interest if we consider that the internalization route/s undertaken by PrPC can be crucial for the ability of different prion strains to infect and to replicate in different cell lines.
UR - http://www.scopus.com/inward/record.url?scp=67149137755&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=67149137755&partnerID=8YFLogxK
U2 - 10.1371/journal.pone.0005829
DO - 10.1371/journal.pone.0005829
M3 - Article
C2 - 19503793
AN - SCOPUS:67149137755
VL - 4
JO - PLoS One
JF - PLoS One
SN - 1932-6203
IS - 6
M1 - e5829
ER -