Regulation of endo-polygalacturonase activity in Saccharomyces cerevisiae.
Regulation of endo-polygalacturonase activity in Saccharomyces cerevisiae.
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DOI：
10.1111/j.1567-1364.2009.00584.x
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发表时间：
2010-02
影响因子：
3.2
通讯作者：
Campbell Louw;Philip R. Young;P. van Rensburg;B. Divol
中科院分区：
文献类型：
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作者：
Campbell Louw;Philip R. Young;P. van Rensburg;B. Divol
酿酒酵母中的果胶溶解活性是由于PGU 1基因编码的内切多聚半乳糖醛酸酶的分泌。已显示降解聚半乳糖醛酸的能力在不同菌株之间不同。在这项研究中，我们试图阐明如何果胶溶解活性调节在S。酿酒酵母，并确定是否有不同的调节手段菌株。比较了来自不同遗传背景的具有不同降解果胶能力的酿酒酵母菌株。发现活性不受PGU 1基因序列差异的调节，而是受该基因转录水平的调节。PGU1的表达由其两个转录因子TEC1和STE12的转录水平决定。半乳糖对PGU1转录的激活被发现是菌株特异性的，独立于菌株是工业菌株还是驯化菌株。筛选EUROSCARF酵母缺失文库中编码多聚半乳糖醛酸酶活性抑制剂和激活剂的基因。14个菌株进行了鉴定，其中一个特定基因的缺失导致多聚半乳糖醛酸酶活性的恢复，这些基因被确定为编码多聚半乳糖醛酸酶活性的抑制剂，并确定了两个激活剂。
Pectolytic activity in Saccharomyces cerevisiae is due to the secretion of an endo-polygalacturonase encoded by the PGU1 gene. The ability to degrade polygalacturonic acid has been shown to vary between different strains. In this study, we attempted to elucidate how pectolytic activity is regulated in S. cerevisiae and to determine whether the means of regulation differ between strains. Saccharomyces cerevisiae strains from different genetic backgrounds, with varying ability to degrade pectin, were compared. Activity was found not to be regulated by sequence differences in the PGU1 gene, but by the transcription level of the gene. Expression of PGU1 was found to be determined by the transcription level of its two transcription factors TEC1 and STE12. The activation of PGU1 transcription by galactose was found to be strain specific, independent of the strain being an industrial or a domesticated one. The EUROSCARF yeast deletion library was screened for genes encoding inhibitors and activators of polygalacturonase activity. Fourteen strains were identified, in which deletion of a specific gene resulted in a recovery of polygalacturonase activity; these genes were identified as encoding inhibitors of polygalacturonase activity, and two activators were identified.