Hinnebusch A G
CRC Crit Rev Biochem. 1986;21(3):277-317. doi: 10.3109/10409238609113614.
Enzymes in diverse amino acid biosynthetic pathways in Saccharomyces cerevisiae are subject to a general amino acid control in which starvation for any amino acid leads to increased levels of the mRNAs encoding these enzymes. The short nucleotide sequence TGACTC, found nontandemly repeated upstream from the coregulated structural genes, serves as a cis-acting site for positive regulation of transcription. Multiple trans-acting repressors and activators have been identified. Most of these factors act indirectly by regulating the level of an activator encoded by the GCN4 gene. This regulation occurs at the level of GCN4 translation and is mediated by sequences in the long 5' leader of GCN4 mRNA. The GCN4 protein is the most likely candidate for the transcriptional activator that interacts with the TGACTC sequences at the structural genes.
酿酒酵母中多种氨基酸生物合成途径中的酶受到一般氨基酸调控，即任何一种氨基酸的饥饿都会导致编码这些酶的mRNA水平升高。在共同调控的结构基因上游非串联重复出现的短核苷酸序列TGACTC，作为转录正调控的顺式作用位点。已鉴定出多种反式作用阻遏物和激活物。这些因子大多通过调节由GCN4基因编码的一种激活物的水平间接发挥作用。这种调控发生在GCN4翻译水平，由GCN4 mRNA长5'前导序列中的序列介导。GCN4蛋白最有可能是与结构基因处的TGACTC序列相互作用的转录激活物。
