Membrane lipid perturbation modifies the set point of the temperature of heat shock response in yeast.
Addition of a saturated fatty acid (SFA) induced a strong increase in heat shock (HS) mRNA transcription when cells were heat-shocked at 37 degrees C, whereas treatment with an unsaturated fatty acid (UFA) reduced or eliminated the level of HS gene transcription at 37 degrees C. Transcription of the delta 9-desaturase gene (Ole1) of Histoplasma capsulatum, whose gene product is responsible for the synthesis of UFA, is up-regulated in a temperature-sensitive strain. We show that when the L8-14C mutant of Saccharomyces cerevisiae, which has a disrupted Ole1 gene, is complemented with its own Ole1 coding region under control of its own promoter or Ole1 promoters of H. capsulatum, the level of HS gene transcription depends on the activity of the promoters. Fluorescence anisotropy of mitochondrial membranes of completed strains corresponded to the different activity of the Ole1 promoter used. We propose that the SFA/UFA ratio and perturbation of membrane lipoprotein complexes are involved in the perception of rapid temperature changes and under HS conditions disturbance of the preexisting membrane physical state causes transduction of a signal that induces transcription of HS genes.
Carratù
L
L
International Institute of Genetics and Biophysics, Consiglio Nazionale delle Ricerche, Naples, Italy.
Franceschelli
S
S
Pardini
C L
CL
Kobayashi
G S
GS
Horvath
I
I
Vigh
L
L
Maresca
B
B
D015152:Blotting, Northern; D005230:Fatty Acids, Nonesterified / Q000494:pharmacology*; D005800:Genes, Fungal; D005816:Genetic Complementation Test; D006360:Heat-Shock Proteins / Q000096:biosynthesis*; D006658:Histoplasma / Q000187:drug effects / Q000378:metabolism*; D006358:Hot Temperature; D007425:Intracellular Membranes / Q000378:metabolism; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism*; D008969:Molecular Sequence Data; D019301:Oleic Acid; D009829:Oleic Acids / Q000494:pharmacology; D010085:Oxidative Phosphorylation; D010101:Oxygen Consumption; D019308:Palmitic Acid; D010169:Palmitic Acids / Q000494:pharmacology; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000096:biosynthesis; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D013229:Stearic Acids / Q000494:pharmacology; D013230:Stearoyl-CoA Desaturase / Q000096:biosynthesis*; D014158:Transcription, Genetic / Q000187:drug effects
D005230:Fatty Acids, Nonesterified; D006360:Heat-Shock Proteins; D009829:Oleic Acids; D010169:Palmitic Acids; D012333:RNA, Messenger; D013229:Stearic Acids; D019301:Oleic Acid; D019308:Palmitic Acid; C031183:stearic acid; D013230:Stearoyl-CoA Desaturase