Genetics, Vol. 165, 23-33, September 2003, Copyright © 2003

Analysis of the Generation and Segregation of Propagons: Entities That Propagate the [PSI+] Prion in Yeast

Brian Coxa, Frederique Nessa, and Mick Tuitea
a Research School of Biosciences, University of Kent, Canterbury, Kent CT2 7NJ, United Kingdom

Corresponding author: Mick Tuite, University of Kent, Canterbury, Kent CT2 7NJ, United Kingdom., m.f.tuite{at}ukc.ac.uk (E-mail)

Communicating editor: M. JOHNSTON

The propagation of the prion form of the yeast Sup35p protein, the so-called [PSI+] determinant, involves the generation and partition of a small number of particulate determinants that we propose calling "propagons." The numbers of propagons in [PSI+] cells can be inferred from the kinetics of elimination of [PSI+] during growth in the presence of a low concentration of guanidine hydrochloride (GdnHCl). Using this and an alternative method of counting the numbers of propagons, we demonstrate considerable clonal variation in the apparent numbers of propagons between different [PSI+] yeast strains, between different cultures of the same [PSI+] yeast strain, and between different cells of the same [PSI+] culture. We provide further evidence that propagon generation is blocked by growth in GdnHCl and that it is largely confined to the S phase of the cell cycle. In addition, we show that at low propagon number there is a bias toward retention of propagons in mother cells and that production of new propagons is very rapid when cells with depleted numbers of propagons are rescued into normal growth medium. The implications of our findings with respect to yeast prion propagation mechanisms are discussed.




This article has been cited by other articles:


Home page
 Proc. Natl. Acad. Sci. USAHome page
A. B. Lindner, R. Madden, A. Demarez, E. J. Stewart, and F. Taddei
Asymmetric segregation of protein aggregates is associated with cellular aging and rejuvenation
PNAS, February 26, 2008; 105(8): 3076 - 3081.
[Abstract] [Full Text] [PDF]

Home page
 Proc. Natl. Acad. Sci. USAHome page
L. J. Byrne, B. S. Cox, D. J. Cole, M. S. Ridout, B. J. T. Morgan, and M. F. Tuite
Cell division is essential for elimination of the yeast [PSI+] prion by guanidine hydrochloride
PNAS, July 10, 2007; 104(28): 11688 - 11693.
[Abstract] [Full Text] [PDF]

Home page
 GENES CELLSHome page
S. Kawai-Noma, S. Ayano, C.-G. Pack, M. Kinjo, M. Yoshida, K. Yasuda, and H. Taguchi
Dynamics of yeast prion aggregates in single living cells.
Genes Cells, September 1, 2006; 11(9): 1085 - 1096.
[Abstract] [Full Text] [PDF]

Home page
 GeneticsHome page
K.-W. Park, J.-S. Hahn, Q. Fan, D. J. Thiele, and L. Li
De Novo Appearance and "Strain" Formation of Yeast Prion [PSI+] Are Regulated by the Heat-Shock Transcription Factor
Genetics, May 1, 2006; 173(1): 35 - 47.
[Abstract] [Full Text] [PDF]

Home page
 Eukaryot CellHome page
J. F. Zenthon, F. Ness, B. Cox, and M. F. Tuite
The [PSI+] Prion of Saccharomyces cerevisiae Can Be Propagated by an Hsp104 Orthologue from Candida albicans
Eukaryot. Cell, February 1, 2006; 5(2): 217 - 225.
[Abstract] [Full Text] [PDF]

Home page
 Proc. Natl. Acad. Sci. USAHome page
Y.-X. Wu, L. E. Greene, D. C. Masison, and E. Eisenberg
Curing of yeast [PSI+] prion by guanidine inactivation of Hsp104 does not require cell division
PNAS, September 6, 2005; 102(36): 12789 - 12794.
[Abstract] [Full Text] [PDF]

Home page
 Eukaryot CellHome page
Y. Song, Y.-x. Wu, G. Jung, Y. Tutar, E. Eisenberg, L. E. Greene, and D. C. Masison
Role for Hsp70 Chaperone in Saccharomyces cerevisiae Prion Seed Replication
Eukaryot. Cell, February 1, 2005; 4(2): 289 - 297.
[Abstract] [Full Text] [PDF]

Home page
 Genes Dev.Home page
R. B. Wickner, H. K. Edskes, B. T. Roberts, U. Baxa, M. M. Pierce, E. D. Ross, and A. Brachmann
Prions: proteins as genes and infectious entities
Genes & Dev., March 1, 2004; 18(5): 470 - 485.
[Full Text] [PDF]