NR AWCM
AU Bruns,C.; Schätzl,H.M.
TI Characterization of cellular interactors of the prion protein
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-03
PT Konferenz-Poster
AB Although a variety of functions has been proposed for the cellular isoform of the prion protein (PrPc), the definitive one still needs to be elucidated. Similarly, the mechanism finally leading to cell death in prion-infected cells is only roughly understood. One way to address these questions is to identify and characterize proteins interacting with PrPc. To search for novel interactors of PrPc we applied the yeast-two-hybrid system (Y2H), screening a neuronal cDNA library with the N-terminal part of PrP as a bait. The N-terminal portion of PrP has been implicated by us in subcellular trafficking and cellular quality control mechanisms (Nunziante et al., 2003; Gilch et al., 2004). Positive interactors found in Y2H were confirmed by co-immunoprecipitation assay and confocal microscopy in cell culture. One of the confirmed proteins was intersectin 1 (ITSN1). ITSN1, a cytosolic, 160 kDa multi-domain scaffold protein is expressed in most cell lines and is involved in different pathways. The interaction with PrP was demonstrated in different cell lines. Interestingly, in prion-infected cells ITSN1 binds preferably to the Scrapie isoform of PrP (PrPsc). In the same complex also Grb2, another scaffold protein and PrPc interactor (Spielhaupter & Schätzl, 2001), was identified. Over-expression of ITSN1 did not alter PrPsc levels, but significantly reduced the amount of surface PrPc. Prion-infected cells over-expressing ITSN1 showed a distinct phenotype, characterized by many vacuole-like structures, probably representing autophagosomes. The role of ITSN1 in autophagy has to be further investigated to see if there is a functional link between ITSN1, PrPc/PrPsc, autophagy, and the resulting cell death following prion infection.
AD Institute of Virology, Prion Research Group, Trogerstr. 30, 81675 Munich, Germany. E-mail: chris.bruns@lrz.tum.de
SP englisch
PO Italien