Acetyl-CoA hydrolase, catalyzing the hydrolysis of acetyl-CoA, is presumably involved in regulating the intracellular acetyl-CoA pool. Recently, a yeast acetyl-CoA hydrolase was purified to homogeneity from Saccharomyces cerevisiae and partially characterized (Lee, F.-J. S., Lin, L.-W., and Smith, J. A. (1989) Eur. J. Biochem. 184, 21-28). In order to study the biological function and regulation of the acetyl-CoA hydrolase, we cloned and sequenced the full length cDNA encoding yeast acetyl-CoA hydrolase. RNA blot analysis indicates that acetyl-CoA hydrolase is encoded by a 2.5-kilobase mRNA. DNA blot analyses of genomic and chromosomal DNA reveal that the gene (so-called ACH1, acetyl-CoA hydrolase) is present as a single copy located on chromosome II. Acetyl-CoA hydrolase is established to be a mannose-containing glycoprotein, which binds concanavalin A. By measuring the levels of ACH1 mRNA and acetyl-CoA hydrolase activity in different growth phases and by examining the effects of various carbon sources, we have demonstrated that ACH1 expression is repressed by glucose.