NR ADGQ
AU Derkatch,I.L.; Bradley,M.E.; Masse,S.V.; Zadorskii,S.P.; Polozkov,G.V.; Inge-Vechtomov,S.G.; Liebman,S.W.
TI Dependence and independence of [PSI(+)] and [PIN(+)]: a two-prion system in yeast?
QU EMBO Journal 2000 May 2; 19(9): 1942-52
PT journal article
AB The [PSI(+)] prion can be induced by overproduction of the complete Sup35 protein, but only in strains carrying the non-Mendelian [PIN(+)] determinant. Here we demonstrate that just as [psi (-)] strains can exist as [PIN(+)] and [pin(-)] variants, [PSI(+)] can also exist in the presence or absence of [PIN(+)]. [PSI(+)] and [PIN(+)] tend to be cured together, but can be lost separately. [PSI(+)]-related phenotypes are not affected by [PIN(+)]. Thus, [PIN(+)] is required for the de novo formation of [PSI(+)], not for [PSI(+)] propagation. Although [PSI(+)] induction is shown to require [PIN(+)] even when the only overexpressed region of Sup35p is the prion domain, two altered prion domain fragments circumventing the [PIN(+)] requirement are characterized. Finally, in strains cured of [PIN(+)], prolonged incubation facilitates the reappearance of [PIN(+)]. Newly appearing [PIN(+)] elements are often unstable but become stable in some mitotic progeny. Such reversibility of curing, together with our previous demonstration that the inheritance of [PIN(+)] is non-Mendelian, supports the hypothesis that [PIN(+)] is a prion. Models for [PIN(+)] action, which explain these findings, are discussed.
MH Amino Acid Sequence; Biological Factors/genetics/*physiology; Cold; Crosses, Genetic; Fungal Proteins/*chemistry/genetics/*metabolism; Gene Expression; Guanidine/pharmacology; Mitosis; Models, Biological; Molecular Sequence Data; Peptide Fragments/chemistry/genetics/metabolism; Phenotype; Plasmids/genetics; Prions/*chemistry/genetics/*metabolism; Protein Structure, Tertiary/drug effects; *Saccharomyces cerevisiae/chemistry/drug effects/genetics/growth &; development; Sequence Deletion/genetics; Support, Non-U.S. Gov't; Support, U.S. Gov't, P.H.S.; Time Factors
AD Laboratory for Molecular Biology, Department of Biological Sciences, University of Illinois at Chicago, 900 South Ashland Avenue, Chicago, IL 60607, USA
SP englisch
PO England