The frequency of yeast [PSI+] prion formation is increased during chronological ageing
Authors:Shaun H. Speldewinde1 and Chris M. Grant1
1 University of Manchester, Faculty of Biology, Medicine and Health, The Michael Smith Building, Oxford Road, Manchester, M13 9PT, UK.
Keywords:
prion, yeast, chronological ageing, autophagy.
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Conflict of interest statement:
The authors declare no conflict of interest.
Please cite this article as:
Shaun H. Speldewinde and Chris M. Grant (2017). The frequency of yeast [PSI+] prion formation is increased during chronological ageing. Microbial Cell 4(4): 127-132.
© 2017 Speldewinde and Grant. This is an open-access article released under the terms of the Creative Commons Attribution (CC BY) license, which allows the unrestricted use, distribution, and reproduction in any medium, provided the original author and source are acknowledged.
Abstract:
Ageing involves a time-dependent decline in a variety of intracellular mechanisms and is associated with cellular senescence. This can be exacerbated by prion diseases which can occur in a sporadic manner, predominantly during the later stages of life. Prions are infectious, self-templating proteins responsible for several neurodegenerative diseases in mammals and several prion-forming proteins have been found in yeast. We show here that the frequency of formation of the yeast [PSI+] prion, which is the altered form of the Sup35 translation termination factor, is increased during chronological ageing. This increase is exacerbated in an atg1 mutant suggesting that autophagy normally acts to suppress age-related prion formation. We further show that cells which have switched to [PSI+] have improved viability during chronological ageing which requires active autophagy. [PSI+] stains show increased autophagic flux which correlates with increased viability and decreased levels of cellular protein aggregation. Taken together, our data indicate that the frequency of [PSI+] prion formation increases during yeast chronological ageing, and switching to the [PSI+] form can exert beneficial effects via the promotion of autophagic flux.
doi: 10.15698/mic2017.04.568
Volume 4, pp. 127 to 132, published 27/03/2017.