Global gene expression analysis of Aspergillus nidulans reveals metabolic shift and transcription suppression under hypoxia
Global gene expression analysis of Aspergillus nidulans reveals metabolic shift and transcription suppression under hypoxia
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DOI：
10.1007/s00438-010-0576-x
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发表时间：
2010-12-01
影响因子：
3.1
通讯作者：
Takaya, Naoki
中科院分区：
文献类型：
--
作者：
Masuo, Shunsuke;Terabayashi, Yasunobu;Takaya, Naoki
低氧对大多数需要氧气才能增殖的丝状真菌构成了挑战。在这里，我们使用全基因组DNA微阵列来研究在低氧和常氧条件下暴露后nidulans基因表达的整体转录变化。曝气影响了2864个基因的表达(占真菌基因总数的27%)，其中50%在低氧条件下被诱导或抑制。上调的基因包括糖酵解、乙醇生产、三羧酸(TCA)循环和绕过TCA循环两个步骤的伽马-氨基丁酸酯(GABA)分流。低氧条件下乙醇和乳酸的产生表明葡萄糖是通过糖酵解途径发酵成这些化合物的。由于GABA分流绕过了氧化戊二酸脱氢酶催化的TCA循环中NADH的生成反应，低氧的Nidulans细胞消除了多余的NADH。低氧下调了一些参与RNA聚合酶II转录启动的基因，并降低了细胞的mRNA含量。这些功能可以通过复氧恢复，这表明根结线虫控制着全球转录，以适应低氧环境。这项研究首次表明，低氧可引起根结线虫的系统性转录反应。
Hypoxia imposes a challenge upon most filamentous fungi that require oxygen for proliferation. Here, we used whole genome DNA microarrays to investigate global transcriptional changes in Aspergillus nidulans gene expression after exposure to hypoxia followed by normoxia. Aeration affected the expression of 2,864 genes (27% of the total number of genes in the fungus), of which 50% were either induced or repressed under hypoxic conditions. Up-regulated genes included those for glycolysis, ethanol production, the tricarboxylic acid (TCA) cycle, and for the gamma-aminobutyrate (GABA) shunt that bypasses two steps of the TCA cycle. Ethanol and lactate production under hypoxic conditions indicated that glucose was fermented to these compounds via the glycolytic pathway. Since the GABA shunt bypasses the NADH-generating reaction of the TCA cycle catalyzed by oxoglutarate dehydrogenase, hypoxic A. nidulans cells eliminated excess NADH. Hypoxia down-regulated some genes involved in transcription initiation by RNA polymerase II, and lowered the cellular mRNA content. These functions were resumed by re-oxygenation, indicating that A. nidulans controls global transcription to adapt to a hypoxic environment. This study is the first to show that hypoxia elicits systematic transcriptional responses in A. nidulans.