The trans-10,cis-12 conjugated linoleic acid increases triacylglycerol hydrolysis in yeast Saccharomyces cerevisiae

AIMS:

The trans-10,cis-12 conjugated linoleic acid (CLA) is known for its antilipogenic effect but the mechanism is not fully clear. In this study, potential of yeast (Saccharomyces cerevisiae) metabolism to offer evidence for the mechanism was investigated.

METHODS AND RESULTS:

Inhibitory effect of CLA on lipid accumulation was studied by analyzing the transcript abundance of selected genes involved in TAG synthesis (LRO1, DGA1, ARE1 and ARE2) in the presence of the two bioactive CLA isomers: trans-10,cis-12 and the cis-9,trans-11 CLA. None of the enzymes was reduced in transcription but expression of ARE2 was induced by trans-10,cis-12 CLA. However, the ARE2 overexpression didn't contribute to lipid accumulation. The expression of the Δ9 desaturase gene, OLE1, was reduced by cis-9,trans-11 but not by the trans-10,cis-12 isomer. In TGL3/TGL4-knock-out strain the triacylglycerol content remained high also in the CLA fed cells.

CONCLUSIONS:

Triacylglycerol hydrolysis rather than their synthesis was the most probable reason for the reduced lipid content in yeast induced by CLA.

SIGNIFICANCE AND IMPACT OF THE STUDY:

This study revealed new aspects of the functionality of CLA in eukaryotic lipid metabolism. Yeast was proven to be an applicable model to study further the mechanism of trans-10,cis-12 CLA functionality on lipid metabolism. This article is protected by copyright. All rights reserved.