[Rnq1 protein protects [PSI^(+)] prion from effect of the PNM mutation]

Area of Science:

• * Yeast genetics
• * Molecular biology
• * Protein aggregation

Background:

• * Prion networks, like the interaction between [PSI^(+)] and [PIN^(+)] in Saccharomyces cerevisiae, demonstrate complex protein interactions.
• * In [PIN^(+)] yeast cells, Rnq1p prion aggregates act as templates for Sup35p aggregation, initiating [PSI^(+)].

Purpose of the Study:

• * To investigate the role of Rnq1p in maintaining the [PSI^(+)] prion, particularly under conditions that promote prion loss.
• * To explore the complex interplay between different prion proteins in yeast.

Main Methods:

• * Yeast strains with specific mutations in the SUP35 gene (Q61K, Q62K) were utilized.
• * The stability of the [PSI^(+)] prion was assessed in the presence and absence of Rnq1p.

Main Results:

• * The presence of Rnq1p significantly reduced the loss of the [PSI^(+)] prion in yeast strains carrying the SUP35 Q61K, Q62K double mutation.
• * This indicates that Rnq1p plays a protective role in stabilizing the [PSI^(+)] prion.

Conclusions:

• * Rnq1p actively participates in the maintenance of the [PSI^(+)] prion in yeast.
• * These findings support the existence of prion interaction networks involving prionogenic and prion-like proteins.