The Saccharomyces cerevisiae TGL2 gene encodes a protein with lipolytic activity and can complement an Escherichia coli diacylglycerol kinase disruptant

Abstract

Escherichia coli cells with a disrupted diacylglycerol kinase gene are unable to grow on media containing arbutin due to a lethal accumulation of diacylglycerol. In order to isolate genes from the yeast Saccharomyces cerevisiae involved in diacylglycerol metabolism we complemented an E. coli diacylglycerol kinase disruptant with a yeast genomic library and transformants were selected capable of growing in the presence of arbutin. Using this method, a gene (TGL2) was isolated coding for a protein resembling lipases from Pseudomonas. After expression of the TGL2 gene in E. coli, lipolytic activity towards triacylglycerols and diacylglycerols with short-chain fatty acids could be measured. Therefore, it is very likely that the TGL2 gene can complement the E. coli diacylglycerol kinase disruptant, because it encodes a protein that degrades the diacylglycerol accumulated after growth in the presence of arbutin. Disruption of the TGL2 gene in S. cerevisiae did not result in a detectable phenotype. The role of the Tgl2 protein in lipid degradation in yeast is still unclear.

The Saccharomyces cerevisiae YLL012/YEH1, YLR020/YEH2, and TGL1 Genes Encode a Novel Family of Membrane-Anchored Lipases That Are Required for Steryl Ester Hydrolysis

“…Tgl1 has been proposed to be a triglyceride-specific lipase on the basis of its homology to lipases from humans and rats, but enzymatic activity of Tgl1 against triacylglycerol has never been demonstrated (1). TGL2, on the other hand, was found to prevent lethal accumulation of diacylglycerol (DAG) in a DAG kinase mutant Escherichia coli strain grown on arbutin, an artificial phosphoglycerol acceptor (49). Tgl2p displays sequence homology to Pseudomonas triacylglycerol lipases, and its expression in E. coli confers lipolytic activity against triacylglycerol and DAG with short-chain fatty acids (49).…”

“…TGL2, on the other hand, was found to prevent lethal accumulation of diacylglycerol (DAG) in a DAG kinase mutant Escherichia coli strain grown on arbutin, an artificial phosphoglycerol acceptor (49). Tgl2p displays sequence homology to Pseudomonas triacylglycerol lipases, and its expression in E. coli confers lipolytic activity against triacylglycerol and DAG with short-chain fatty acids (49). The physiological function of TGL2 in yeast, however, has not been characterized.…”

Systematic analysis of yeast strains with possible defects in lipid metabolism

“…It would be most interesting to study this gene and its product in more detail, because triacylglycerol lipase(s) of the yeast have not yet been identified at the molecular level. Two other yeast genes possibly involved in triacylglycerol metabolism, namely TGL1 (Abraham et al, 1992) and TGL2 (van Heusden et al, 1998), were recently detected. Both gene products, however, could not be unambiguously identified as triacylglycerol lipases.…”

Genome mining of fungal lipid-degrading enzymes for industrial applications

“…that the TGL2-like protein might not be essential in yeast and fungi, which is in agreement with previous studies describing the growth ability of the deletion strain of the TGL2 gene on minimal medium (Van Heusden et al, 1998;Ham et al, 2010). However, it has been found that the TGL2 protein is required for the viability of cells treated with antimitotic drugs (Ham et al, 2010).…”