Exogenous fatty acids transcriptionally control the expression of a wide variety of eukaryotic genes, many of which encode proteins involved in lipid metabolism. To identify gene products involved in the lipid signalling pathway, a reporter plasmid containing the 5'-upstream region of a gene demonstrated to be repressed by unsaturated fatty acids (OLE1) was fused in frame to the Escherichia coli gene lacZ encoding β-galactosidase. Saccharomyces cerevisiae mutants defective in transcriptional control by lipids were identified and this class of mutants has been named frm (fatty acid repression mutant). The mutants were organized into six complementation groups designated frm-6. Mutants from two of the complementation groups, frm1 and frm3, were also defective in their ability to activate a reporter construct containing the 5'-upstream region of POX1. POX1 has been shown to be transcriptionally activated in the presence of unsaturated fatty acids. frm2 was rescued by a region of DNA localized to chromosome III. This region contained an open reading frame of 579 nucleotides predicted to encode a M(r) 21,116 polypeptide. The upstream region of FRM2 contained a number of potential response elements which have previously been identified as important in regulating gene expression in response to glucose and certain fatty acids. Consistent with this observation, lacZ activity driven by FRM2 or frm2 promoters was induced two- to three-fold dependent upon the carbon and fatty acid source utilized. The properties of FRM2 suggest that it functions in the fatty acid signalling pathway and that it is itself regulated by fatty acids.
|Original language||English (US)|
|Number of pages||13|
|State||Published - Mar 30 1996|
- Oleic acid