Specificity of prion assembly in vivo. [PSI+] and [PIN+] form separate structures in yeast

J Biol Chem. 2004 Dec 3;279(49):51042-8. doi: 10.1074/jbc.M410611200. Epub 2004 Sep 30.

Abstract

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.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amyloid / chemistry
  • Detergents / pharmacology
  • Electrophoresis, Polyacrylamide Gel
  • Genes, Recessive
  • Guanidine / chemistry
  • Peptide Termination Factors
  • Prions / chemistry*
  • Protein Conformation
  • Saccharomyces cerevisiae Proteins / chemistry
  • Sodium Dodecyl Sulfate / chemistry
  • Temperature

Substances

  • Amyloid
  • Detergents
  • Peptide Termination Factors
  • Prions
  • RNQ1 protein, S cerevisiae
  • SUP35 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins
  • Sodium Dodecyl Sulfate
  • Guanidine