Prions, protein homeostasis, and phenotypic diversity.
Prions are fascinating but often misunderstood protein aggregation phenomena. The traditional association of the mammalian prion protein with disease has overshadowed a potentially more interesting attribute of prions: their ability to create protein-based molecular memories. In fungi, prions alter the relationship between genotype and phenotype in a heritable way that diversifies clonal populations. Recent findings in yeast indicate that prions might be much more common than previously realized. Moreover, prion-driven phenotypic diversity increases under stress, and can be amplified by the dynamic maturation of prion-initiating states. In this article, we suggest that these qualities allow prions to act as 'bet-hedging' devices that facilitate the adaptation of yeasts to stressful environments, and might speed the evolution of new traits.
Halfmann
Randal
R
Whitehead Institute for Biomedical Research, Cambridge, MA, USA.
Alberti
Simon
S
Lindquist
Susan
S
D044127:Epigenesis, Genetic / Q000502:physiology; D015966:Gene Expression Regulation, Fungal; D005979:Glutathione Peroxidase / Q000502:physiology; D006706:Homeostasis / Q000235:genetics; D010641:Phenotype; D011328:Prions / Q000235:genetics* / Q000502:physiology; D011487:Protein Conformation; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology
D011328:Prions; D029701:Saccharomyces cerevisiae Proteins; D005979:Glutathione Peroxidase; C067020:URE2 protein, S cerevisiae