Prion protein gene polymorphisms in Saccharomyces cerevisiae
Prion protein gene polymorphisms in Saccharomyces cerevisiae
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DOI：
10.1046/j.1365-2958.2003.03608.x
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发表时间：
2003-08-01
影响因子：
3.6
通讯作者：
Tuite, MF
中科院分区：
文献类型：
--
作者：
Resende, CG;Outeiro, TF;Tuite, MF
酵母酿酒酵母基因组编码几种蛋白质，在实验室菌株中，可以采取稳定的，可传播的朊病毒形式。在每种情况下，这需要蛋白质的富含Asn/Gln的朊病毒形成结构域（PrD）是完整的。为了进一步了解这种不寻常的性质的进化意义，我们已经检查了四个不同的朊病毒基因和它们相应的PrD，从一些自然发生的S。啤酒。在所研究的16个菌株中的4个菌株中，我们鉴定出SUP 35基因的一个新等位基因（SUP 35 Delta 19），该等位基因在N-末端PrD内含有19个氨基酸的缺失，该缺失消除了Sup 35 p的朊病毒性质。在这些菌株中，第二朊病毒基因，RNQ 1，被发现是高度多态性的，与8个不同的RNQ 1等位基因检测在6个二倍体菌株研究。相反，对于另一个朊病毒基因（URE 2）和编码PrD的NEW 1基因序列，未检测到显著程度的DNA多态性。对RNQ 1和SUP 35的天然等位基因的分析表明，所鉴定的各种多态性与编码序列内的DNA串联重复（6、12、33、42或57 bp）相关。RNQ 1基因内DNA重复序列的扩展和收缩可能提供了一种进化机制，可以确保[朊病毒+]和[朊病毒（-）]状态之间的快速变化。
The yeast Saccharomyces cerevisiae genome encodes several proteins that, in laboratory strains, can take up a stable, transmissible prion form. In each case, this requires the Asn/Gln-rich prion-forming domain (PrD) of the protein to be intact. In order to further understand the evolutionary significance of this unusual property, we have examined four different prion genes and their corresponding PrDs, from a number of naturally occurring strains of S. cerevisiae. In 4 of the 16 strains studied we identified a new allele of the SUP35 gene (SUP35Delta19) that contains a 19-amino-acid deletion within the N-terminal PrD, a deletion that eliminates the prion property of Sup35p. In these strains a second prion gene, RNQ1, was found to be highly polymorphic, with eight different RNQ1 alleles detected in the six diploid strains studied. In contrast, for one other prion gene (URE2) and the sequence of the NEW1 gene encoding a PrD, no significant degree of DNA polymorphism was detected. Analysis of the naturally occurring alleles of RNQ1 and SUP35 indicated that the various polymorphisms identified were associated with DNA tandem repeats (6,12, 33, 42 or 57 bp) within the coding sequences. The expansion and contraction of DNA repeats within the RNQ1 gene may provide an evolutionary mechanism that can ensure rapid change between the [PRION+] and [prion(-)] states.