The acetyl-CoA synthetase gene ACS2 of the yeast Saccharomyces cerevisiae is coregulated with structural genes of fatty acid biosynthesis by the transcriptional activators Ino2p and Ino4p

The yeast Saccharomyces cerevisiae contains two acetyl-CoA synthetase genes, ACS1 and ACS2. While ACS1 transcription is glucose repressible, ACS2 shows coregulation with structural genes of fatty acid biosynthesis. The ACS2 upstream region contains an ICRE (inositol/choline-responsive element) as an activating sequence and requires the regulatory genes INO2 and INO4 for maximal expression. We demonstrate in vitro binding of the heterodimeric activator protein Ino2p/Ino4p to the ACS2 promoter. In addition, the pleiotropic transcription factor Abf1p also binds to the ACS2 control region. The identification of ACS2 activating elements also found upstream of ACC1, FAS1 and FAS2 suggests a role of this acetyl-CoA synthetase isoenzyme for the generation of the acetyl-CoA pool required for fatty acid biosynthesis. (C) 1997 Federation of European Biochemical Societies.