An acyl-CoA : cholesterol acyltransferase (ACAT)-related gene is involved in the accumulation of triacylglycerols in Saccharomyces cerevisiae

The major route for the synthesis of triacylglycerol (TAG) in yeast as well as in all TAG-accumulating organisms has been suggested to occur via the a cylation of diacylglycerol (DAG) by acyl-CoA:diacylglycerol acyltransferase (DAGAT). Genes encoding DAGAT have been identified in both plant and anima l tissues. These genes show strong sequence similarities to genes encoding acyl-CoA: cholesterol acyltransferase (ACAT), So far no Saccharomyces cerev isiae DAGAT gene has been published; however, two ACAT-like genes, ARE1 and ARE2, are present in the yeast genome. Both these genes have been suggeste d to be involved in the synthesis of sterol esters. We have now shown that the ARE1 gene in yeast also is involved in the synthesis of TAG, whereas th e ARE2 gene is more specifically involved in the synthesis of sterol esters .