Dynamics of yeast prion aggregates in single living cells

• Published in: Genes to cells : devoted to molecular & cellular mechanisms 2006-09, Vol.11 (9), p.1085-1096
• Main Authors: Kawai‐Noma, Shigeko, Ayano, Satoru, Pack, Chan‐Gi, Kinjo, Masataka, Yoshida, Masasuke, Yasuda, Kenji, Taguchi, Hideki
• Format: Article
• Language: English
• Subjects: Cell Survival; Computational Biology; Peptide Termination Factors; Phenotype; Prions - chemistry; Prions - metabolism; Protein Binding; Protein Structure, Quaternary; Recombinant Fusion Proteins - chemistry; Recombinant Fusion Proteins - metabolism; Saccharomyces cerevisiae - cytology; Saccharomyces cerevisiae - metabolism; Saccharomyces cerevisiae Proteins - chemistry; Saccharomyces cerevisiae Proteins - metabolism; Spectrometry, Fluorescence; Time Factors
• ISSN: 1356-9597; 1365-2443
• DOI: 10.1111/j.1365-2443.2006.01004.x

Prions are propagating proteins that are ordered protein aggregates, in which the phenotypic trait is retained in the altered protein conformers. To understand the dynamics of the prion aggregates in living cells, we directly monitored the fate of the aggregates using an on‐chip single‐cell cultivation system as well as fluorescence correlation spectroscopy (FCS). Single‐cell imaging revealed that the visible foci of yeast prion Sup35 fused with GFP are dispersed throughout the cytoplasm during cell growth, but retain the prion phenotype. FCS showed that [PSI+] cells, irrespective of the presence of foci, contain diffuse oligomers, which are transmitted to their daughter cells. Single‐cell observations of the oligomer‐based transmission provide a link between previous in vivo and in vitro analyses of the prion and shed light on the relationship between the protein conformation and the phenotype.