THE SACCHAROMYCES-CEREVISIAE TGL2 GENE ENCODES A PROTEIN WITH LIPOLYTIC-ACTIVITY AND CAN COMPLEMENT AN ESCHERICHIA-COLI DIACYLGLYCEROL KINASE DISRUPTANT

Escherichia coli cells with a disrupted diacylglycerol kinase gene are unable to grow on media containing arbutin due to a lethal accumulati on of diacylglycerol. In order to isolate genes from the yeast Sacchar omyces cerevisiae involved in diacylglycerol metabolism we complemente d an E. coli diacylglycerol kinase disruptant with a yeast genomic lib rary and transformants were selected capable of growing in the presenc e of arbutin. Using this method, a gene (TGL2) was isolated coding for a protein resembling lipases from Pseudomonas. After expression of th e TGL2 gene in E. coli, lipolytic activity towards triacylglycerols an d diacylglycerols with short-chain fatty acids could be measured. Ther efore, it is very likely that the TGL2 gene can complement the E. coli diacylglycerol kinase disruptant, because it encodes a protein that d egrades 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 Tg12 protein in lipid degra dation in yeast is still unclear. The nucleotide sequence published he re has been submitted to the EMBL sequence data bank and is available under accession number X98000. (C) 1998 John Wiley & Sons, Ltd.