M410_8d 227..230

NATURE | VOL 410 | 8 MARCH 2001 | www.nature.com 227 12. DePace, A. H., Santoso, A., Hillner, P. & Weissman, J. S. A critical role for amino-terminal glutamine/ asparagine repeats in the formation and propagation of a yeast prion. Cell 93, 1241–1252 (1998). 13. Patino, M. M., Liu, J. J., Glover, J. R. & Lindquist, S. Support for the prion hypothesis for inheritance of a phenotypic trait in yeast. Science 273, 622–626 (1996). 14. King, C. Y. et al. Prion-inducing domain 2-114 of yeast Sup35 protein transforms in vitro into amyloid-like filaments. Proc. Natl Acad. Sci. USA 94, 6618–6622 (1997). 15. Glover, J. R. et al. Self-seeded fibers formed by Sup35, the protein determinant of [PSI+], a heritable prion-like factor of S. cerevisiae. Cell 89, 811–819 (1997). 16. Kushnirov, V. V., Kochneva-Pervukhova, N. V., Chechenova, M. B., Frolova, N. S. & Ter-Avanesyan, M. D. Prion properties of the Sup35 protein of yeast Pichia methanolica. EMBO J. 19, 324–331 (2000). 17. Santoso, A., Chien, P., Osherovich, L. Z. & Weissman, J. S. Molecular basis of a yeast prion species barrier. Cell 100, 277–288 (2000). 18. Chernoff, Y. O. et al. Evolutionary conservation of prion-forming abilities of the yeast Sup35 protein. Mol. Microbiol. 35, 865–876 (2000). 19. Liu, J. J. & Lindquist, S. Oligopeptide-repeat expansions modulate ’protein-only’ inheritance in yeast. Nature 400, 573–576 (1999). 20. Wickner, R. B. [URE3] as an altered URE2 protein: evidence for a prion analog in Saccharomyces cerevisiae. Science 264, 566–569 (1994). 21. Sondheimer, N. & Lindquist, S. Rnq1: an epigenetic modifier of protein function in yeast. Mol. Cell 5, 163–172 (2000). 22. Tuite, M. F., Mundy, C. R. & Cox, B. S. Agents that cause a high frequency of genetic change from [psi] to [psi] in Saccharomyces cerevisiae. Genetics 98, 691–711 (1981). 23. Zhou, P. et al. The yeast non-Mendelian factor [ETA] is a variant of [PSI], a prion-like form of release factor eRF3. EMBO J. 18, 1182–1191 (1999). 24. Serio, T. R. et al. Nucleated conformational conversion and the replication of conformational information by a prion determinant. Science 289, 1317–1321 (2000). 25. Paushkin, S. V., Kushnirov, V. V., Smirnov, V. N. & Ter-Avanesyan, M. D. In vitro propagation of the prion-like state of yeast Sup35 protein. Science 277, 381–383 (1997). 26. Kochneva-Pervukhova, N. V. et al. Mechanism of inhibition of Psi prion determinant propagation by a mutation of the N-terminus of the yeast Sup35 protein. EMBO J. 17, 5805–5810 (1998). 27. Appel, T. R., Dumpitak, C., Matthiesen, U. & Riesner, D. Prion rods contain an inert polysaccharide scaffold. Biol. Chem. 380, 1295–1306 (1999). 28. Klein, T. R., Kirsch, D., Kaufmann, R. & Riesner, D. Prion rods contain small amounts of two host sphingolipids as revealed by thin-layer chromatography and mass spectrometry. Biol. Chem. 379, 655–666 (1998). 29. Kocisko, D. A. et al. Species specificity in the cell-free conversion of prion protein to protease-resistant forms: a model for the scrapie species barrier. Proc. Natl Acad. Sci. USA 92, 3923–3927 (1995). 30. Wilesmith, J. W., Ryan, J. B. & Atkinson, M. J. Bovine spongiform encephalopathy—Epidemiologic studies on the origin.. Vet. Rec. 128, 199–203 (1991).