EXPRESSION AND TARGETING OF SYRIAN-HAMSTER PRION PROTEIN-INDUCED BY HEAT-SHOCK IN TRANSGENIC DROSOPHILA-MELANOGASTER

To evaluate the fruit fly as a model for studying neurodegenerative di seases caused by prions, transgenic flies were generated by introducin g the Syrian hamster prion protein (SHaPrP) gene into the Drosophila m elanogaster germ line by P element-mediated transformation. Nine trans genic lines were isolated; induction of transgenes that had been place d under the control of the Drosophila heat shock promoter, hsp 70, res ulted in the synthesis of full-length SHaPrP. The relative molecular w eight of the recombinant protein was lower than that of authentic SHaP rP due to incomplete processing of Asn-linked CHOs. To determine the c ellular localization of SHaPrP, Drosophila Schneider line 2 cells were transfected with the same constructs used for fly transformation. Hea t shock induced SHaPrP was anchored to the surface of S2 cells by a gl ycolipid, demonstrating that the carboxy-terminal glycolipidation sign al of SHaPrP is recognized by this evolutionarily distant host. When S HaPrP was synthesized in transgenic flies constitutively by subjecting them to heat pulses continuously, no difference in their lifespans co mpared with controls was detected. Furthermore, expression of SHaPrP f or 20 days did not produce protease resistant SHaPrP, which is the maj or and possibly only component of the infectious prion. In contrast to transgenic mice overexpressing SHaPrP, which develop a profound neuro myopathy, no disease phenotype was associated with expression of SHaPr P over the entire lifespan of transgenic flies.