NR APLE
AU Ripaud,L.; Maillet,L.; Cullin,C.
TI The mechanisms of [URE3] prion elimination demonstrate that large aggregates of Ure2p are dead-end products
QU EMBO Journal 2003 Oct 1; 22(19): 5251-9
PT journal article
AB The yeast prion [URE3] is a self-propagating inactive form (the propagon) of the Ure2 protein. Ure2p is composed of two domains: residues 1-93 - the prion-forming domain (PFD) - and the remaining C-terminal part of the protein, which forms the functional domain involved in nitrogen catabolite repression. Guanidine hydrochloride, and the overproduction of Ure2p 1-65 or Ure2-GFP have been shown to induce the elimination of [URE3]. We demonstrate here, two different curing mechanisms: the inhibition of [URE3] replication by guanidine hydrochloride and its destruction by Ure2p aggregation. Such aggregation is observed if PFD or Ure2-GFP are overproduced and in heterozygous URE2/URE2-GFP, [URE3] diploids. We found that the GFP foci associated with the presence of the prion were dead-end products, the propagons remaining soluble. Surprisingly, [URE3] propagated via the Ure2-GFP fusion protein alone is resistant to these two curing mechanisms and cannot promote the formation of foci. The relationship between aggregation, prion and Hsp104 gives rise to a model in which the propagon is in equilibrium with larger aggregates and functional protein.
MH Guanidine/metabolism; Prions/*metabolism; Saccharomyces cerevisiae/*metabolism; Saccharomyces cerevisiae Proteins/*metabolism; Support, Non-U.S. Gov't
AD IBGC, CNRS UMR5095, 1, rue Camille Saint Saens, 33077 Bordeaux , France.
SP englisch
PO England