Antagonistic Interactions between Yeast [PSI+] and [URE3] Prions and Curing of [URE3] by Hsp70 Protein Chaperone Ssa1p but Not by Ssa2p

ABSTRACT The yeast [PSI +], [URE3], and [PIN +] genetic elements are prion forms of Sup35p, Ure2p, and Rnq1p, respectively. Overexpression of Sup35p, Ure2p, or Rnq1p leads to increased de novo appearance of [PSI +], [URE3], and [PIN +], respectively. This inducible appearance of [PSI +] was shown to be dependent on the presence of [PIN +] or [URE3] or overexpression of other yeast proteins that have stretches of polar residues similar to the prion-determining domains of the known prion proteins. In a similar manner, [PSI +] and [URE3] facilitate the appearance of [PIN +]. In contrast to these positive interactions, here we find that in the presence of [PIN +], [PSI +] and [URE3] repressed each other's propagation and de novo appearance. Elevated expression of Hsp104 and Hsp70 (Ssa2p) had little effect on these interactions, ruling out competition between the two prions for limiting amounts of these protein chaperones. In contrast, we find that constitutive overexpression of SSA1 but not SSA2 cured cells of [URE3], uncovering a specific interaction between Ssa1p and [URE3] and a functional distinction between these nearly identical Hsp70 isoforms. We also find that Hsp104 abundance, which critically affects [PSI +] propagation, is elevated when [URE3] is present. Our results are consistent with the notion that proteins that have a propensity to form prions may interact with heterologous prions but, as we now show, in a negative manner. Our data also suggest that differences in how [PSI +] and [URE3] interact with Hsp104 and Hsp70 may contribute to their antagonistic interactions.

[1]  R. Wickner,et al.  [URE3] Prion Propagation in Saccharomyces cerevisiae: Requirement for Chaperone Hsp104 and Curing by Overexpressed Chaperone Ydj1p , 2000, Molecular and Cellular Biology.

[2]  Jeffrey H. Miller.  Experiments in molecular genetics , 1972 .

[3]  T. Cooper,et al.  Identification of sequences responsible for transcriptional activation of the allantoate permease gene in Saccharomyces cerevisiae , 1989, Molecular and cellular biology.

[4]  C. Nierras,et al.  The dominant PNM2- mutation which eliminates the psi factor of Saccharomyces cerevisiae is the result of a missense mutation in the SUP35 gene. , 1994, Genetics.

[5]  Y. Chernoff,et al.  Genetic and environmental factors affecting the de novo appearance of the [PSI+] prion in Saccharomyces cerevisiae. , 1997, Genetics.

[6]  P. Philippsen,et al.  New heterologous modules for classical or PCR‐based gene disruptions in Saccharomyces cerevisiae , 1994, Yeast.

[7]  D. Masison,et al.  A role for cytosolic hsp70 in yeast [PSI(+)] prion propagation and [PSI(+)] as a cellular stress. , 2000, Genetics.

[8]  S W Liebman,et al.  Role of the chaperone protein Hsp104 in propagation of the yeast prion-like factor [psi+]. , 1995, Science.

[9]  Jonathan S Weissman,et al.  Multiple Gln/Asn-Rich Prion Domains Confer Susceptibility to Induction of the Yeast [PSI+] Prion , 2001, Cell.

[10]  R. Wickner,et al.  The [URE3] prion is an aggregated form of Ure2p that can be cured by overexpression of Ure2p fragments. , 1999, Proceedings of the National Academy of Sciences of the United States of America.

[11]  B. Chesebro,et al.  Heterologous PrP molecules interfere with accumulation of protease-resistant PrP in scrapie-infected murine neuroblastoma cells , 1994, Journal of virology.

[12]  Stephen J. DeArmond,et al.  Transgenetic studies implicate interactions between homologous PrP isoforms in scrapie prion replication , 1990, Cell.

[13]  S. Paushkin,et al.  Propagation of the yeast prion‐like [psi+] determinant is mediated by oligomerization of the SUP35‐encoded polypeptide chain release factor. , 1996, The EMBO journal.

[14]  S. Lindquist,et al.  Self-Seeded Fibers Formed by Sup35, the Protein Determinant of [PSI +], a Heritable Prion-like Factor of S. cerevisiae , 1997, Cell.

[15]  K. Wüthrich,et al.  Prion-inducing domain 2-114 of yeast Sup35 protein transforms in vitro into amyloid-like filaments. , 1997, Proceedings of the National Academy of Sciences of the United States of America.

[16]  Susan Lindquist,et al.  Protein disaggregation mediated by heat-shock protein Hspl04 , 1994, Nature.

[17]  R. Wickner,et al.  The prion model for [URE3] of yeast: spontaneous generation and requirements for propagation. , 1997, Proceedings of the National Academy of Sciences of the United States of America.

[18]  T. Cooper,et al.  Saccharomyces cerevisiae GATA Sequences Function as TATA Elements during Nitrogen Catabolite Repression and When Gln3p Is Excluded from the Nucleus by Overproduction of Ure2p* , 2000, The Journal of Biological Chemistry.

[19]  S. Lindquist,et al.  The role of Sis1 in the maintenance of the [RNQ+] prion , 2001, The EMBO journal.

[20]  M. Lindau.  The story of /r/ , 1980 .

[21]  S. Lindquist,et al.  Heat-shock protein 104 expression is sufficient for thermotolerance in yeast. , 1996, Proceedings of the National Academy of Sciences of the United States of America.

[22]  F. Lacroute.  Non-Mendelian Mutation Allowing Ureidosuccinic Acid Uptake in Yeast , 1971, Journal of bacteriology.

[23]  S. Liebman,et al.  Prions Affect the Appearance of Other Prions The Story of [PIN+] , 2001, Cell.

[24]  R. Wickner,et al.  A protein required for prion generation: [URE3] induction requires the Ras-regulated Mks1 protein. , 2000, Proceedings of the National Academy of Sciences of the United States of America.

[25]  E. Craig,et al.  Self-regulation of 70-kilodalton heat shock proteins in Saccharomyces cerevisiae , 1990, Molecular and cellular biology.

[26]  Y. Chernoff,et al.  Multicopy SUP35 gene induces de-novo appearance of psi-like factors in the yeast Saccharomyces cerevisiae , 1993, Current Genetics.

[27]  R. Wickner,et al.  [URE3] as an altered URE2 protein: evidence for a prion analog in Saccharomyces cerevisiae. , 1994, Science.

[28]  M. Tuite,et al.  Mechanism of inhibition of Ψ+ prion determinant propagation by a mutation of the N‐terminus of the yeast Sup35 protein , 1998, The EMBO journal.

[29]  R. Sikorski,et al.  A system of shuttle vectors and yeast host strains designed for efficient manipulation of DNA in Saccharomyces cerevisiae. , 1989, Genetics.

[30]  I. Stansfield,et al.  The products of the SUP45 (eRF1) and SUP35 genes interact to mediate translation termination in Saccharomyces cerevisiae. , 1995, The EMBO journal.

[31]  S. Lindquist,et al.  Antagonistic Interactions between Yeast Chaperones Hsp104 and Hsp70 in Prion Curing , 1999, Molecular and Cellular Biology.

[32]  R. Wickner,et al.  Prion-Inducing Domain of Yeast Ure2p and Protease Resistance of Ure2p in Prion-Containing Cells , 1995, Science.

[33]  S. Lindquist,et al.  Nucleated conformational conversion and the replication of conformational information by a prion determinant. , 2000, Science.

[34]  R. Wickner,et al.  Prion domain initiation of amyloid formation in vitro from native Ure2p. , 1999, Science.

[35]  M. Ter‐Avanesyan,et al.  Structure and Replication of Yeast Prions , 1998, Cell.

[36]  M. Tuite,et al.  The [URE3] phenotype: evidence for a soluble prion in yeast , 2002, EMBO reports.

[37]  E. Craig,et al.  Differential regulation of the 70K heat shock gene and related genes in Saccharomyces cerevisiae , 1984, Molecular and cellular biology.

[38]  S. Lindquist,et al.  Chaperone-supervised conversion of prion protein to its protease-resistant form. , 1997, Proceedings of the National Academy of Sciences of the United States of America.

[39]  J R Glover,et al.  Support for the Prion Hypothesis for Inheritance of a Phenotypic Trait in Yeast , 1996, Science.

[40]  P. Lansbury,et al.  The chemistry of scrapie infection: implications of the 'ice 9' metaphor. , 1995, Chemistry & biology.