Transcriptional regulation of respiration in yeast metabolizing differently repressive carbon substrates.
Transcriptional regulation of respiration in yeast metabolizing differently repressive carbon substrates.
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DOI：
10.1186/1752-0509-4-12
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发表时间：
2010-02-18
影响因子：
--
通讯作者：
Sauer U
中科院分区：
文献类型：
--
作者：
Fendt SM;Sauer U
根据碳源的不同，酿酒酵母表现出不同程度的呼吸作用。这些范围从乙醇的完全呼吸到几乎完全发酵，因此对葡萄糖的呼吸程度很低。虽然许多关键的调节器是已知的这些极端情况下，我们在这里集中在调节器是相关的中间水平的呼吸。我们解决这个问题，通过连接呼吸的功能程度，通过酶丰度的转录调控。具体来说，我们研究了有氧分批培养与不同的抑制性碳源葡萄糖，甘露糖，半乳糖和丙酮酸。基于13 C通量分析，我们发现呼吸对细胞能量产生的贡献在葡萄糖和甘露糖上基本上不存在，在半乳糖上居中，在丙酮酸上最高。在每种条件下，通过GFP融合定量40种呼吸酶的体内丰度。在半乳糖和丙酮酸的部分和完全呼吸底物上生长期间，几种TCA循环和呼吸链酶显着上调。从这些酶水平和已知的调控网络结构，我们确定了一个给定的转录因子引起协调表达变化的概率。最有可能调节不同呼吸程度的转录因子是Gcr 1 p、Cat 8 p、Rtg蛋白和Hap复合物。对于后三个，我们通过量化相应缺失菌株的呼吸程度和生物量产量来证实它们对呼吸的重要性。Cat 8 p是野生型呼吸所必需的，独立于其已知的致炎基因的激活。在部分呼吸条件下，Rtg蛋白和Hap复合物对于野生型样呼吸是必需的。在完全呼吸条件下，Hap-复合物而不是Rtg-蛋白是呼吸所必需的。
Depending on the carbon source, Saccharomyces cerevisiae displays various degrees of respiration. These range from complete respiration as in the case of ethanol, to almost complete fermentation, and thus very low degrees of respiration on glucose. While many key regulators are known for these extreme cases, we focus here on regulators that are relevant at intermediate levels of respiration. We address this question by linking the functional degree of respiration to transcriptional regulation via enzyme abundances. Specifically, we investigated aerobic batch cultures with the differently repressive carbon sources glucose, mannose, galactose and pyruvate. Based on 13C flux analysis, we found that the respiratory contribution to cellular energy production was largely absent on glucose and mannose, intermediate on galactose and highest on pyruvate. In vivo abundances of 40 respiratory enzymes were quantified by GFP-fusions under each condition. During growth on the partly and fully respired substrates galactose and pyruvate, several TCA cycle and respiratory chain enzymes were significantly up-regulated. From these enzyme levels and the known regulatory network structure, we determined the probability for a given transcription factor to cause the coordinated expression changes. The most probable transcription factors to regulate the different degrees of respiration were Gcr1p, Cat8p, the Rtg-proteins and the Hap-complex. For the latter three ones we confirmed their importance for respiration by quantifying the degree of respiration and biomass yields in the corresponding deletion strains. Cat8p is required for wild-type like respiration, independent of its known activation of gluconeogenic genes. The Rtg-proteins and the Hap-complex are essential for wild-type like respiration under partially respiratory conditions. Under fully respiratory conditions, the Hap-complex, but not the Rtg-proteins are essential for respiration.
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影响因子：
12.3
作者：
Blank LM;Kuepfer L;Sauer U
通讯作者：
Sauer U
影响因子：
2.8
作者：
HERRERO, P;FERNANDEZ, R;MORENO, F
通讯作者：
MORENO, F
影响因子：
7
作者：
Kuepfer, L;Sauer, U;Blank, LM
通讯作者：
Blank, LM
影响因子：
4.4
作者：
Duetz, WA;Rüedi, L;Witholt, B
通讯作者：
Witholt, B
影响因子：
4.4
作者：
Bro, C;Knudsen, S;Nielsen, J
通讯作者：
Nielsen, J