ZAP1-mediated modulation of triacylglycerol levels in yeast by transcriptional control of mitochondrial fatty acid biosynthesis

The transcriptional activator Zap1p maintains zinc homeostasis in Saccharomyces cerevisiae. In this study, we examined the role of Zap1p in triacylglycerol (TAG) metabolism. The expression of ETR1 is reduced in zap1. The altered expression of ETR1 results in reduced mitochondrial fatty acid biosynthesis and reduction in lipoic acid content in zap1. The transcription factor Zap1 positively regulates ETR1 expression. Deletion of ETR1 also causes the accumulation of TAG, and the introduction of ETR1 in zap1 strain rescues the TAG level. These results demonstrated that the compromised mitochondrial fatty acid biosynthesis causes a reduction in lipoic acid and loss of mitochondrial function in zap1. Functional mitochondria are required for the ATP production and defect in mitochondria slow down the process which may channeled carbon towards lipid biosynthesis and stored in the form of TAG.