Transcriptional repression by Kluyveromyces lactis Tup1 in Saccharomyces cerevisiae
Transcriptional repression by Kluyveromyces lactis Tup1 in Saccharomyces cerevisiae
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DOI：
10.1007/s10295-010-0832-4
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发表时间：
2011-01-01
影响因子：
3.4
通讯作者：
Rodriguez Torres, Ana Maria
中科院分区：
文献类型：
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作者：
Lamas-Maceiras, Monica;Angeles Freire-Picos, Maria;Rodriguez Torres, Ana Maria
通用阻遏复合体由酵母Tup1和Ssn6因子组成，是真核生物中保守的全球转录调控因子。在酿酒酵母中，Tup1基因是一种重要的低氧抑制基因，如ANB1，在有氧条件下，Tup1基因的缺失会导致一种絮凝表型。乳酸克鲁维酵母的KlTUP1基因编码的蛋白质与酿酒酵母中的Tup1有83%的相似性。尽管一般结构域保守，但数据库搜索显示缺乏特征的Tup1富含谷氨酰胺结构域(Q1在第96-116位)。相反，该区域存在一个缺乏α-螺旋结构的非保守序列。在酿酒酵母Tup1突变株中，通过在高拷贝和低拷贝载体中表达KlTUP1基因来测试其作为转录抑制因子的能力。用好氧耐受报告菌ANB1-LacZ研究了其抑制效果和对絮凝的影响。在这两个调控系统中，低水平的KlTup1导致适度(类似于30%)的抑制，但当KlTup1拷贝数增加时，只有ANB1报告基因提高了酿酒酵母Tup1的抑制水平。这些结果表明，KlTup1在酿酒酵母中具有作为抑制子的能力。从结构差异的角度讨论了酿酒酵母中达到的较低的抑制作用。
The general repression complex, constituted by the yeast Tup1 and Ssn6 factors, is a conserved global regulator of transcription in eukaryotes. In the yeast Saccharomyces cerevisiae, it is an important repressor of hypoxic genes, such as ANB1, under aerobic conditions and deletion of the TUP1 gene causes a flocculation phenotype. The KlTUP1 gene from the yeast Kluyveromyces lactis encodes for a protein with 83% similarity to Tup1 in S. cerevisiae. Despite the general domain conservation, the database searches showed the absence of a characteristic Tup1 glutamine-rich domain (Q1 at positions 96-116). Instead, there was a non-conserved sequence lacking the alpha-helix structure in this region. The ability to act as a transcriptional repressor was tested by expressing the KlTUP1 gene, in both high- and low-copy vectors, in an S. cerevisiae tup1 mutant strain. Repression effects were studied using the aerobic repressible reporter ANB1-lacZ and the effect on flocculation. In both regulatory systems, low levels of KlTup1 caused moderate (similar to 30%) repression, but when the number of KlTup1 copies was increased, only the ANB1 reporter raised the repression levels of S. cerevisiae Tup1. These results show the capability of KlTup1 to act as a repressor in S. cerevisiae. The lower repression reached in S. cerevisiae is discussed in terms of structural differences.