Carratù L, Franceschelli S, Pardini C L, Kobayashi G S, Horvath I, Vigh L, Maresca B
International Institute of Genetics and Biophysics, Consiglio Nazionale delle Ricerche, Naples, Italy.
Proc Natl Acad Sci U S A. 1996 Apr 30;93(9):3870-5. doi: 10.1073/pnas.93.9.3870.
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.
当细胞在37摄氏度进行热休克处理时，添加饱和脂肪酸（SFA）会导致热休克（HS）mRNA转录显著增加，而用不饱和脂肪酸（UFA）处理则会降低或消除37摄氏度时HS基因的转录水平。荚膜组织胞浆菌的Δ9-去饱和酶基因（Ole1）的转录，其基因产物负责UFA的合成，在一个温度敏感菌株中上调。我们发现，当酿酒酵母的L8-14C突变体（其Ole1基因被破坏）在其自身启动子或荚膜组织胞浆菌的Ole1启动子控制下用其自身的Ole1编码区进行互补时，HS基因的转录水平取决于启动子的活性。完整菌株线粒体膜的荧光各向异性与所使用的Ole1启动子的不同活性相对应。我们提出，SFA/UFA比值和膜脂蛋白复合物的扰动参与了对快速温度变化的感知，并且在热休克条件下，先前存在的膜物理状态的干扰会导致信号转导，从而诱导HS基因的转录。
