Penn M D, Thireos G, Greer H
Mol Cell Biol. 1984 Mar;4(3):520-8. doi: 10.1128/mcb.4.3.520-528.1984.
In Saccharomyces cerevisiae, starvation for a single amino acid results in the derepression of enzyme activities in multiple amino acid biosynthetic pathways. Derepression is a consequence of increased transcription of the genes encoding these enzymes. Analysis of the kinetics of mRNA elevation established that derepression occurs within 5 min of a shift of the culture from rich medium to starvation medium. Any starvation condition was sufficient to trigger an initial high mRNA elevation; however, it was the severity of starvation which determined the steady-state mRNA levels that were subsequently established. The products of the positive regulatory genes AAS101, AAS103, and AAS2 were shown to be required in the initiation phase of this response, whereas the AAS102 gene product was required to maintain the new elevated steady-state mRNA levels. The AAS101 and AAS102 genes were cloned. Consistent with their respective roles in initiation and maintenance of derepression. AAS101 mRNA was found to be expressed at high levels in both rich and starvation media, whereas AAS102 mRNA was derepressed only under starvation conditions. The derepression of AAS102 mRNA is dependent on the AAS101 gene product.
在酿酒酵母中，单一氨基酸饥饿会导致多种氨基酸生物合成途径中的酶活性去阻遏。去阻遏是这些酶编码基因转录增加的结果。对mRNA升高动力学的分析表明，去阻遏在培养物从丰富培养基转移到饥饿培养基后的5分钟内发生。任何饥饿条件都足以引发最初的高mRNA升高；然而，是饥饿的严重程度决定了随后建立的稳态mRNA水平。正向调节基因AAS101、AAS103和AAS2的产物在该反应的起始阶段是必需的，而AAS102基因产物是维持新的升高的稳态mRNA水平所必需的。AAS101和AAS102基因被克隆。与它们在去阻遏起始和维持中的各自作用一致。发现AAS101 mRNA在丰富培养基和饥饿培养基中均高水平表达，而AAS102 mRNA仅在饥饿条件下去阻遏。AAS102 mRNA的去阻遏依赖于AAS101基因产物。
