Characteristics of physiological inducers of the ethanol utilization (alc) pathway in Aspergillus nidulans
Characteristics of physiological inducers of the ethanol utilization (alc) pathway in Aspergillus nidulans
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DOI：
10.1042/bj3640025
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发表时间：
2002-05-15
影响因子：
4.1
通讯作者：
Felenbok, B
中科院分区：
文献类型：
--
作者：
Flipphi, M;Kocialkowska, J;Felenbok, B
Nidulans的乙醇利用途径是丝状真菌中表达最强的基因系统之一，该途径特异的激活子ALCR需要一种诱导化合物的存在来激活其控制下的基因转录。我们最近证明乙醛是乙醇分解代谢的唯一生理诱导剂。在本研究中，我们发现与乙醇的分解代谢有关的化合物，即伯醇、伯单胺和L-苏氨酸是诱导剂，因为它们的分解会导致诱导脂肪醛的产生。这些醛被证明在较低的外界浓度下能有效地诱导alc基因。当乙醇与另一类强直接诱导剂的代表酮混合时，生理诱导剂乙醛作为效应剂占优势。虽然直接诱导剂基本上具有羰基功能，但并不是所有的醛和酮都起诱导剂的作用。区分非诱导性化合物和诱导性化合物的结构特征涉及：(I)脂肪族侧基的长度(S)，(Ii)任何非脂肪族取代基的存在和性质。这些特征使我们能够预测给定的羰基化合物是否会诱导ALE基因。
The ethanol utilization (alc) pathway in Aspergillus nidulans is one of the strongest expressed gene systems in filamentous fungi, The pathway-specific activator AlcR requires the presence of an inducing compound to activate transcription of genes under its control. We have demonstrated recently that acetaldehyde is the sole physiological inducer of ethanol catabolism. In the present study we show that compounds with catabolism related to that of ethanol, i.e. primary alcohols, primary monoamines and L-threonine, act as inducers because their breakdown results in the production Of inducing aliphatic aldehydes. Such aldehydes were shown to induce the alc genes efficiently at low external concentrations. When ethanol is mixed with representatives of another class of strong direct inducers, ketones, the physiological inducer, acetaldehyde, prevails as effector. Although direct inducers essentially carry a carbonyl function, not all aldehydes and ketones act as inducers. Structural features discriminating non-inducing from inducing compounds concern: (i) the length of the aliphatic side group(s), (ii) the presence and nature of any non-aliphatic substituent. These characteristics enable us to predict whether or not a given carbonyl compound will induce the ale genes.