Carbon source-dependent regulation of the acetyl-coenzyme A synthetase-encoding gene ACS1 from Saccharomyces cerevisiae.
The yeast ACS1 gene, encoding acetyl-coenzyme A synthetase (ACS), was cloned using colony hybridization and a facA probe from Aspergillus nidulans. The complete sequence of 1.5 kb of the ACS1 upstream region was determined. Northern hybridization revealed a strong depression of ACS1 transcripts in a strain grown on the nonfermentable carbon sources, acetate or ethanol. In contrast to a previous report, delta acs1 null mutants did not exhibit a growth defect on acetate medium. Indeed, enzyme assays showed the presence of an additional constitutively expressed ACS activity in delta acs1 mutants. The carbon source-dependent expression was further investigated by the use of an ACS1::lacZ fusion gene, showing complete repression on easily fermentable sugars such as glucose, maltose, sucrose or galactose. Binding sites for the yeast general regulatory factors, Abf1p and Reb1p, together with a sequence reminiscent of the recently identified carbon source-responsive element (CSRE), could be detected in the ACS1 upstream region, presumably mediating the observed regulatory phenotype of this ACS isoenzyme.
Kratzer
S
S
Institut für Mikrobiologie, Biochemie und Genetik, Universität Erlangen/Nürnberg, Germany.
Schüller
H J
HJ
D000106:Acetate-CoA Ligase / Q000737:chemistry / Q000235:genetics*; D000085:Acetates / Q000378:metabolism; D000595:Amino Acid Sequence; D001483:Base Sequence; D050260:Carbohydrate Metabolism; D002244:Carbon; D003470:Culture Media; D000431:Ethanol / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic; D015966:Gene Expression Regulation, Fungal; D007527:Isoenzymes / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D012045:Regulatory Sequences, Nucleic Acid; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics*; D014158:Transcription, Genetic
D000085:Acetates; D003470:Culture Media; D007527:Isoenzymes; D000431:Ethanol; D002244:Carbon; D000106:Acetate-CoA Ligase