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

Abstract

SummaryThe 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 zap1D. The altered expression of ETR1 results in reduced mitochondrial fatty acid biosynthesis and reduction in lipoic acid content in zap1D. The transcription factor Zap1 positively regulates ETR1 expression. Deletion of ETR1 also causes the accumulation of TAG, and the introduction of ETR1 in zap1D 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 zap1D. 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.

Genome‐wide screening of budding yeast with honokiol to associate mitochondrial function with lipid metabolism

“…Apoptosis‐induced mitochondrial dysfunction diverts fatty acids into TAG synthesis and formation of LDs . A study of mitochondrial defects shows that ZAP1 deletion slows ATP production, which may channel carbon flow toward lipid biosynthesis and storage as TAG . In combination, these studies suggest that dysfunctional mitochondria with decreased ATP production may divert carbon flow to synthesize TAG for storage in LDs.…”

Arabidopsis serine/threonine/tyrosine protein kinase phosphorylates oil body proteins that regulate oil content in the seeds

“…The total lipid content was extracted from yeast cells expressing the different constructs (OLE1, STYK, OLE1 + STYK). The extracted lipids were converted to total fatty acid methyl ester (FAMEs) and analyzed as described previously 34 .…”

Effect of cadmium on essential metals and their impact on lipid metabolism in Saccharomyces cerevisiae

“…The trace element Zn plays a vital role in growth, development, and cell functioning (Singh et al 2016) and serves as a cofactor for various essential proteins such as lipid metabolism proteins, alcohol dehydrogenase, Cu/Zn superoxide dismutase, chaperones, DNA or RNA polymerases, and ribosomal proteins (Regalla and Lyons 2005). Cd exhibits similar physical and chemical properties with Zn.…”

“…Cd accumulation and Cd-mediated toxicity decrease Zn influx (Brzóska and Moniuszko-Jakoniuk 2001). Zn homeostasis is closely linked to lipid metabolism, and Zn deficiency activates Zap1 and causes lipid accumulation (Han et al 2001;Singh et al 2016). Cd exposure to wild-type (WT) yeast cells significantly upregulated Zn transporters, ZRT1 and ZRT2, but reduced the intracellular Zn levels.…”

“…Intriguingly, the ZRT1 mutant strains were resistant to Cd and prevented Cd overload compared to the WT cells and ZRT2 mutant strains (Gitan et al 2003;Rajakumar et al 2016b). During Zn depletion, phospholipid metabolism is regulated by ZAP1 (Zhao and Eide 1996b;Koch et al 2014), and membrane phospholipids, especially phosphatidylethanolamine (PE) and phosphatidylinositol (PI) are altered in S. cerevisiae (Carman and Han 2007;Singh et al 2016). Cd exposure significantly increased the phospholipids in yeast cells (Muthukumar et al 2011;Rajakumar et al 2016a), but decreased phosphatidylcholine (PC), PE, and phosphatidylserine levels in ZRT1 mutant cells.…”