NR AWFT
AU Goggin,K.; Bissonnette,C.; Grenier,C.; Roucou,X.
TI Enforced dimerization of cellular prion protein results in prion deposition and vacuolation in cultured 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 PA-19
PT Konferenz-Poster
AB Prion deposition and spongiosis are two recognized hallmarks of transmissible spongiform encephalopathies (TSEs) in humans and animals. Despite intensive research, these pathological features are still poorly understood. Since prion deposits are composed of aggregated cellular prion protein (PrPc), an appealing hypothesis is that the first step of their production may consist in the induction of proximity between individual PrPc molecules. Accordingly, enforcing dimerization or/and oligomerization of PrPc could result in the formation of such deposits. We engineered fusion proteins between human PrPc and one or two copies of an FK506 binding domain, Fv1. In the presence of AP20187, a homodimerizer ligand that binds Fv1, proteins containing one or two Fv1 modules are forced to interact and to dimerize or oligomerize, respectively. One or two Fv1 modules were inserted in the unstructured N-terminal domain of PrPc to generate Fv1- and Fv2-tagged PrPc, respectively. Addition of AP20187 to neuronal and non-neuronal cell cultures expressing Fv1-PrP or Fv2-PrP resulted in the release and deposition of extracellular prion aggregates resistant to proteinase K. Since similar results were observed in cells expressing Fv1-PrP and Fv2-PrP, we conclude that first, prion dimers spontaneously combine and form high-order aggregates that are released from the plasma membrane; and second, all the information responsible for PrPc aggregation, release, and deposition is encrypted in the PrPc molecule. Neuronal cells also undergo vacuolation. These findings strongly argue that dimerization of PrPc is the initial molecular event in the pathology. Our study provides a basis for elucidating molecular mechanisms responsible for the neuropathogenesis of TSEs.
AD Department of Biochemistry, Faculty of Medicine, University of Sherbrooke, Sherbrooke, Québec J1H 5N4, Canada. E-mail: xavier.roucou@usherbrooke.ca
SP englisch
PO Italien