Regulation of alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (AldDH) in Aspergillus nidulans

Publisher Website
Google Scholar
Abstract
There is a single major alcohol dehydrogenase (ADH) and a single major aldehyde dehydrogenase (AldDH) in A. nidulans. ADH and AldDH are induced by ethanol and by acetaldehyde and are subject to C catabolite repression. ADH and AldDH are necessary for the utilization of ethanol and of threonine, indicating that both compounds are utilized via acetaldehyde. ADH and AldDH each give a single major activity band on gel electrophoresis. Sodium dodecyl sulfate polyacrylamide gel electrophoresis of cell extracts shows at least 2 similar ADH polypeptides of approximate relative molecular mass (r.m.m.) 41,000 and 2 similar AldDH polypeptides of approximate r.m.m. 57,000. The in vitro translation of mRNA from induced C derepressed wild-type cells gives up to 3 ADH polypeptides in the r.m.m. range 39,000-43,000 and an AldDH polypeptide of approximate r.m.m. 47,000. The mRNA from uninduced, C repressed wild-type cells does not direct the synthesis of the ADH and AldDH polypeptides. The regulation of ADH and AldDH is probably at the level of transcription and/or post-transcriptional modification. The probable explanation of the multiple ADH polypeptides is post-transcriptional modification of the mRNA. Allyl alcohol mutants were made and studied.