Genesis and variability of [PSI] prion factors in Saccharomyces cerevisiae.
Genesis and variability of [PSI] prion factors in Saccharomyces cerevisiae.
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DOI：
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发表时间：
1996-12
期刊：
影响因子：
3.3
通讯作者：
I. Derkatch;Y. Chernoff;V. Kushnirov;S. Inge-Vechtomov;S. Liebman
中科院分区：
文献类型：
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作者：
I. Derkatch;Y. Chernoff;V. Kushnirov;S. Inge-Vechtomov;S. Liebman
我们先前已经证明，含有完整SUP35基因的多拷贝质粒能够诱导非孟德尔因子[PSI]的出现。这一结果后来被其他人解释为一种模型的关键证据，该模型假设[PSI]是Sup35蛋白的自我修饰的、类似Pron的构象衍生物。在这里，我们支持这一解释，证明是Sup35蛋白的过度生产，而不是SUP35 DNA或mRNA的过量导致了[PSI]的出现。我们还发现Sup35p的“Prion诱导区”位于N-末端，与另一种酵母Pron Ure2p的“Prion诱导区”一样，先前已被证明不同于该蛋白的功能区。这表明，这种嵌合组织可能是一些普恩分子的常见模式。最后，我们发现，相同的Sup35蛋白的过量生产在同一酵母菌株中诱导了不同效率和不同有丝分裂稳定性的[PSI]因子。我们认为，不同的含有[PSI]的衍生物类似于神秘的哺乳动物Pron菌株，并且是由Sup35p的不同构象变体产生的。
We have previously shown that multicopy plasmids containing the complete SUP35 gene are able to induce the appearance of the non-Mendelian factor [PSI]. This result was later interpreted by others as a crucial piece of evidence for a model postulating that [PSI] is a self-modified, prion-like conformational derivative of the Sup35 protein. Here we support this interpretation by proving that it is the overproduction of Sup35 protein, and not the excess of SUP35 DNA or mRNA that causes the appearance of [PSI]. We also show that the "prion-inducing domain" of Sup35p is in the N-terminal region, which, like the "prion-inducing domain" of another yeast prion, Ure2p, was previously shown to be distinct from the functional domain of the protein. This suggests that such a chimeric organization may be a common pattern of some prion elements. Finally, we find that [PSI] factors of different efficiencies and different mitotic stabilities are induced in the same yeast strain by overproduction of the identical Sup35 protein. We suggest that the different [PSI]-containing derivatives are analogous to the mysterious mammalian prion strains and result from different conformational variants of Sup35p.