The PNM2 mutation in the prion protein domain of SUP35 has distinct effects on different variants of the [PSI+] prion in yeast
The PNM2 mutation in the prion protein domain of SUP35 has distinct effects on different variants of the [PSI+] prion in yeast
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DOI：
10.1007/s002940050433
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发表时间：
1999-03-01
期刊：
影响因子：
2.5
通讯作者：
Liebman, SW
中科院分区：
文献类型：
--
作者：
Derkatch, IL;Bradley, ME;Liebman, SW
我们先前已经描述了可以在相同的遗传背景中获得并维持的酵母朊病毒[PSI+]的不同变体。这些[PSI+]变体在无义抑制效率、有丝分裂稳定性和GuHCl治愈效率方面不同，可能对应于Sup 35 p的不同[PSI+]朊病毒构象或不同类型的朊病毒聚集体。在这里，我们研究了过表达突变等位基因的SUP 35的影响，并发现不同的影响弱和强[PSI+]变体：弱[PSI+]因子的抑制表型增加，而强[PSI+]因子的抑制作用减少。使用的SUP 35突变最初被描述为“Psi不再”突变（PNM 2），因为它导致[PSI+]的丢失。然而，在我们的研究中使用的菌株中没有一个[PSI+]变体被PNM 2治愈。事实上，当过表达时，PNM 2诱导了弱和强[PSI+]变体的从头出现，其效率与过表达的野生型SUP 35等位基因大致相同。我们的数据表明，在该地区的寡肽重复在Sup 35 p的N-末端由于PNM 2突变的变化修改，但不损害，朊病毒结构域的Sup 35 p的功能。
We have previously described different variants of the yeast prion [PSI+] that can be obtained and maintained in the same genetic background. These [PSI+] variants, which differ in the efficiency of nonsense suppression, mitotic stability and the efficiency of curing by GuHCl, may correspond to different [PSI+] prion conformations of Sup35p or to different types of prion aggregates. Here we investigate the effects of overexpressing a mutant allele of SUP35 and find different effects on weak and strong [PSI+] variants: the suppressor phenotype of weak [PSI+] factors is increased, whereas the suppressor effect of strong [PSI+] factors is reduced. The SUP35 mutation used was originally described as a "Psi no more" mutation (PNM2) because it caused loss of [PSI+]. However, none of the [PSI+] variants in the strains used in our study were cured by PNM2. Indeed, when overexpressed, PNM2 induced the de novo appearance of both weak and strong [PSI+] variants with approximately the same efficiency as the overexpressed wild-type SUP35 allele. Our data suggest that the change in the region of oligopeptide repeats in the Sup35p N-terminus due to the PNM2 mutation modifies, but does not impair, the function of the prion domain of Sup35p.