Specificity of prion assembly in vivo. [PSI+] and [PIN+] form separate structures in yeast.
The yeast prions [PSI+] and [PIN+] are self-propagating amyloid aggregates of the Gln/Asn-rich proteins Sup35p and Rnq1p, respectively. Like the mammalian PrP prion "strains," [PSI+] and [PIN+] exist in different conformations called variants. Here, [PSI+] and [PIN+] variants were used to model in vivo interactions between co-existing heterologous amyloid aggregates. Two levels of structural organization, like those previously described for [PSI+], were demonstrated for [PIN+]. In cells with both [PSI+] and [PIN+] the two prions formed separate structures at both levels. Also, the destabilization of [PSI+] by certain [PIN+] variants was shown not to involve alterations in the [PSI+] prion size. Finally, when two variants of the same prion that have aggregates with distinct biochemical characteristics were combined in a single cell, only one aggregate type was propagated. These studies demonstrate the intracellular organization of yeast prions and provide insight into the principles of in vivo amyloid assembly.
Laboratory for Molecular Biology, University of Illinois, Chicago, Illinois 60607, USA.
Sviatoslav
S
Bagriantsev
Susan W
SW
Liebman
D000682:Amyloid / Q000737:chemistry; D003902:Detergents / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D005808:Genes, Recessive; D019791:Guanidine / Q000737:chemistry; D010454:Peptide Termination Factors; D011328:Prions / Q000737:chemistry*; D011487:Protein Conformation; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry; D013696:Temperature
D000682:Amyloid; D003902:Detergents; D010454:Peptide Termination Factors; D011328:Prions; C404807:RNQ1 protein, S cerevisiae; C068068:SUP35 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D012967:Sodium Dodecyl Sulfate; D019791:Guanidine