ADHII in Aspergillus nidulans is induced by carbon starvation stress.
In Aspergillus nidulans there are three NAD(+)-dependent alcohol dehydrogenases (ADHs) that are capable of utilizing ethanol as a substrate. ADHI is the physiological enzyme of ethanol catabolism and ADHIII is induced under conditions of anaerobiosis. The physiological role of ADHII (structural gene alcB) is unknown. We have measured beta-galactosidase in a transformant with an alcB::lacZ fusion and have shown that alcB is maximally expressed under conditions of carbon starvation. The behavior of the alcB::lacZ transformant suggests a hierarchy of repressing carbon sources characteristic of repression by the general carbon catabolite repressor protein, CreA, but in a creA(d)30 background the transformant shows only partial derepression of beta-galactosidase on 1% glucose compared to the creA+ strain. Our results suggest that, in addition to carbon catabolite repression acting via CreA, a CreA-independent mechanism is involved in induction of alcB on carbon starvation.
Jones
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Department of Biological Sciences, University of Hull, Hull, HU6 7RX, United Kingdom.
Fairhurst
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V
Sealy-Lewis
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HM
D000426:Alcohol Dehydrogenase / Q000096:biosynthesis* / Q000235:genetics; D001233:Aspergillus nidulans / Q000201:enzymology* / Q000378:metabolism; D002244:Carbon / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism; D004790:Enzyme Induction; D004794:Enzyme Repression; D000431:Ethanol / Q000378:metabolism; D005656:Fungal Proteins / Q000096:biosynthesis* / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D009154:Mutation; D012097:Repressor Proteins / Q000378:metabolism
C074202:ALCR protein, Aspergillus nidulans; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D012097:Repressor Proteins; C071237:CreA protein, Aspergillus nidulans; D000431:Ethanol; D002244:Carbon; D000426:Alcohol Dehydrogenase