Propagation of the [PIN+] prion by fragments of Rnq1 fused to GFP

Prions are viewed as enigmatic infectious entities whose genetic properties are enciphered solely in an array of self-propagating protein aggregate conformations. Rnq1, a yeast protein with yet unknown function, forms a prion named [PIN ⁺ ] for its ability to facilitate the de novo induction of another prion, [PSI ⁺ ]. Here we investigate a set of RNQ1 truncations that were designed to cover major Rnq1 sequence elements similar to those important for the propagation of other yeast prions: a region rich in asparagines and glutamines and several types of oligopeptide repeats. Proteins encoded by these RNQ1 truncations were tested for their ability to (a) join (decorate) pre-existing [PIN ⁺ ] aggregates made of wild-type Rnq1 and (b) maintain the heritable aggregated state in the absence of wild-type RNQ1. While the possible involvement of particular sequence elements in the propagation of [PIN ⁺ ] is discussed, the major result is that the efficiency of transmission of [PIN ⁺ ] from wild-type Rnq1 to a fragment decreased with the fragment’s length. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.