Moriyama H, Edskes H K, Wickner R B
Laboratory of Biochemistry and Genetics, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0830, USA.
Mol Cell Biol. 2000 Dec;20(23):8916-22. doi: 10.1128/MCB.20.23.8916-8922.2000.
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, overproduction of Hsp104 does not affect the stability of [URE3], in contrast to what is found for the [PSI(+)] prion, which is known to be cured by either overproduction or deficiency of Hsp104. Like Hsp104, the Hsp40 class chaperone Ydj1p, with the Hsp70 class Ssa1p, can renature proteins. We find that overproduction of Ydj1p results in a gradual complete loss of [URE3]. The involvement of protein chaperones in the propagation of [URE3] indicates a role for protein conformation in inheritance.
[URE3]非染色体遗传元件是Ure2蛋白的一种感染性形式（朊病毒），显然是一种自我传播的淀粉样变性。我们发现，HSP104的插入突变或缺失会导致无法传播[URE3]朊病毒。我们的结果表明，Hsp104是维持两种独立酵母朊病毒的共同因素。然而，与[PSI(+)]朊病毒不同，Hsp104的过量表达不会影响[URE3]的稳定性，已知[PSI(+)]朊病毒可通过Hsp104的过量表达或缺陷来治愈。与Hsp104一样，Hsp40类伴侣蛋白Ydj1p与Hsp70类Ssa1p一起可以使蛋白质复性。我们发现Ydj1p的过量表达会导致[URE3]逐渐完全丧失。蛋白质伴侣在[URE3]传播中的参与表明蛋白质构象在遗传中起作用。
