NR AOGX
AU Narayanan,S.; Bosl,B.; Walter,S.; Reif,B.
TI Importance of low-oligomeric-weight species for prion propagation in the yeast prion system Sup35/Hsp104
QU Proceedings of the National Academy of Sciences of the United States of America 2003 Aug 5; 100(16): 9286-91
PT journal article
AB The [PSI+] determinant of Saccharomyces cerevisiae, consisting of the cytosolic translation termination factor Sup35, is a prion-type genetic element that induces an inheritable conformational change and converts the Sup35 protein into amyloid fibers. The molecular chaperone Hsp104 is required to maintain self-replication of [PSI+]. We observe in vitro that addition of catalytic amounts of Hsp104 to the prion-determining region of the NM domain of Sup35, Sup355-26, results in the dissociation of oligomeric Sup35 into monomeric species. Several intermediates of Sup355-26 could be detected during this process. Strong interactions are found between Hsp104 and hexameric/tetrameric Sup355-26, whereas the intermediate and monomeric "release" forms show a decreased affinity with respect to Hsp104, as monitored by saturation transfer difference and diffusion-ordered NMR spectroscopic experiments. Interactions are mediated mostly by the side chains of Gln, Asn, and Tyr residues in Sup355-26. No interaction can be detected between Hsp104 and higher oligomeric states (>/=8) of Sup355-26. Taking into account the fact that Hsp104 is required for maintenance of [PSI+], we suggest that low-oligomeric-weight species of Sup35 are important for prion propagation in yeast.
MH Asparagine/chemistry; Cytosol/metabolism; Fungal Proteins/*chemistry; Glutamine/chemistry; Heat-Shock Proteins/*chemistry; Magnetic Resonance Spectroscopy; Models, Biological; Peptide Synthesis; Peptides/chemistry; Prions/*chemistry; Protein Binding; Protein Conformation; Saccharomyces cerevisiae/metabolism; Saccharomyces cerevisiae Proteins/*chemistry; Support, Non-U.S. Gov't; Time Factors; Tyrosine/chemistry
AD Institut für Organische Chemie und Biochemie and Lehrstuhl für Biotechnologie, Technische Universität München, Lichtenbergstrasse 4, 85747 Garching, Germany.
SP englisch
PO USA