SPECIFIC INDUCTION OF CATABOLISM AND ITS RELATION TO REPRESSION OF BIOSYNTHESIS IN ARGININE METABOLISM OF SACCHAROMYCES-CEREVISIAE
SPECIFIC INDUCTION OF CATABOLISM AND ITS RELATION TO REPRESSION OF BIOSYNTHESIS IN ARGININE METABOLISM OF SACCHAROMYCES-CEREVISIAE
复制标题
DOI：
10.1016/0022-2836(78)90417-5
复制
发表时间：
1978-01-01
影响因子：
5.6
通讯作者：
WIAME, JM
中科院分区：
文献类型：
--
作者：
DUBOIS, E;HIERNAUX, D;WIAME, JM
实验结果支持先前提出的特异性诱导S.酿酒酵母，其与精氨酸生物合成酶的终产物阻遏的连接。这些数据支持真核生物中代谢负调控的发生。操纵子区域，一个用于谷胱甘肽转移酶，另一个用于鸟氨酸转氨酶，被鉴定。操纵基因突变是完全组成型的。与分解代谢阻遏物CARGR的发生相容的突变导致部分多效性组成性。诱导过程和生物合成酶的阻遏之间的联系是由于代谢信号的共同受体，一种矛盾阻遏物ARGR，具有合成代谢酶的常用阻遏物的性质，并在CARGR水平上发挥诱导剂的作用;该级联过程模拟阳性对照。argR-突变，通过产生缺陷的ARGR，打开合成代谢酶的合成和关闭分解代谢酶的合成。ARGR的双重作用通过突变argRIId的分离得到证实，该突变argRIId与通常的argR-突变引起的缺陷性质相反，导致对诱导分解代谢酶的显性活性亢进，但对抑制合成代谢酶保留隐性活性减退。这种矛盾的阻遏物是在相反的代谢之间相互平衡排斥所必需的功能。许多操纵基因组成型突变的酶，cargA +0-，改变酶的水平到一个类似的值，从而定义了遗传功能。这些突变之一，cargA +0h，除了具有不寻常的遗传行为外，还导致产生两倍于cargA +0-的酶。这表明，存在的另一个遗传区域附近的结构基因的这种酶和一个额外的调节功能进行分析，在一个单独的文件。
Experimental results are presented in support of the model previously proposed for specific induction of the synthesis of enzymes for arginine catabolism in S. cerevisiae, and its connection with end-product repression of arginine biosynthetic enzymes. The data support the occurrence of negative regulation of metabolism in a eukaryote. Operator regions, one for arginase and another for ornithine transaminase, are identified. The operator mutations are fully constitutive. A mutation compatible with the occurrence of a catabolic repressor, CARGR, leads to partial pleiotropic constitutivity. The connection between the induction process and the repression of biosynthetic enzymes is due to a common receptor of metabolic signals, an ambivalent repressor ARGR endowed with the property of a usual repressor for anabolic enzymes and playing the role of inducer at the level of CARGR; this cascade process simulates a positive control. argR- mutations, by producing defective ARGR, turn on anabolic enzyme synthesis and turn off the synthesis of catabolic enzymes. The dual role of ARGR is confirmed by the isolation of a mutation argRIId which, in contrast to the defective properties caused by usual argR- mutations, causes a dominant hyperactivity toward induction of a catabolic enzyme, but retains recessive hypoactivity toward repression of an anabolic enzyme. Such an ambivalent repressor is a function necessary for mutual, balanced exclusion between opposite metabolisms. Many operator constitutive mutations for arginase, cargA+0-, change the level of enzyme to a similar value, thus defining a genetic function. One of these mutations, cargA+0h, in addition to having unusual genetic behavior, leads to production of twice as much arginase as cargA+0-. This suggests that existence of another genetic region near the structural gene for this enzyme and an additional regulatory function to be analyzed in a separate paper.