Reed Brendon Wickner

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A cytoplasmically inherited element, [URE3], allows yeast to use ureidosuccinate in the presence of ammonium ion. Chromosomal mutations in the URE2 gene produce the same phenotype. [URE3] depends for its propagation on the URE2 product (Ure2p), a negative regulator of enzymes of nitrogen metabolism. Saccharomyces cerevisiae strains cured of [URE3] with(More)
[URE3] is a prion (infectious protein) of the Ure2 protein of yeast. In vitro, Ure2p can form amyloid filaments, but direct evidence that these filaments constitute the infectious form is still missing. Here we demonstrate that recombinant Ure2p converted into amyloid can infect yeast cells lacking the prion. Infection produced a variety of [URE3] variants.(More)
The genetic properties of the [URE3] non-Mendelian element of Saccharomyces cerevisiae suggest that it is a prion (infectious protein) form of Ure2p, a regulator of nitrogen catabolism. In extracts from [URE3] strains, Ure2p was partially resistant to proteinase K compared with Ure2p from wild-type extracts. Overexpression of Ure2p in wild-type strains(More)
The L-A double-stranded RNA virus of Saccharomyces cerevisiae encodes its major coat protein (80 kDa) and a minor single-stranded RNA binding protein (180 kDa) that has immunological cross-reactivity with the major coat protein. The sequence of L-A cDNA clones revealed two open reading frames (ORF), ORF1 and ORF2. These two reading frames overlap by 130(More)
The L-A double-stranded RNA (dsRNA) virus of Saccharomyces cerevisiae has two open reading frames (ORFs). ORF1 encodes the 80-kDa major coat protein (gag). ORF2, which is expressed only as a 180-kDa fusion protein with ORF1, encodes a single-stranded RNA-binding domain and has the consensus sequence for RNA-dependent RNA polymerases of (+)-strand and(More)
Prions are "infectious" proteins. When Sup35, a yeast translation termination factor, is aggregated in its [PSI(+)] prion form its function is compromised. When Rnq1 is aggregated in its [PIN(+)] prion form, it promotes the de novo appearance of [PSI(+)]. Heritable variants (strains) of [PSI(+)] with distinct phenotypes have been isolated and are analogous(More)
About 1.9% of ribosomes translating the gag open reading frame of the yeast L-A double-stranded RNA virus positive strand undergo a -1 frameshift and continue translating in the pol open reading frame to make a 170-kDa gag-pol fusion protein. The importance of frameshifting efficiency for viral propagation was tested in a system where the M1 (killer(More)
The [URE3] nonchromosomal genetic element is an infectious form (prion) of the Ure2 protein, apparently a self-propagating amyloidosis. We find that an insertion mutation or deletion of HSP104 results in inability to propagate the [URE3] prion. Our results indicate that Hsp104 is a common factor in the maintenance of two independent yeast prions. However,(More)
The structure of the yeast L-A virus was determined by X-ray crystallography at 3.4 A resolution. The L-A dsRNA virus is 400 A in diameter and contains a single protein shell of 60 asymmetric dimers of the coat protein, a feature common among the inner protein shells of dsRNA viruses and probably related to their unique mode of transcription and(More)