Regulation of alcR, the positive regulatory gene of the ethanol utilization regulon of Aspergillus nidulans

Abstract

The alcR positive control gene is necessary for the expression of both alcA (coding for alcohol dehydro-genase ADH I.) and aldA (coding for aldehyde dehydro-genase, AldDH) in Aspergillus nidulans. Using a cloned alcR probe and Northern blots analysis we show that: (1)alcR itself is inducible; (2)alcR inducibility depends on the expression of the alcR gene Itself; and (3) alcR is subject to carbon catabolite repression and its expression Is controlled by the negatively acting creA wide specificity gene. The repression of alcR is sufficient to explain the cariaon catabolite repression of ADH I and AldDH.