Sumrada R, Cooper T G
J Gen Microbiol. 1978 Sep;108(1):45-56. doi: 10.1099/00221287-108-1-45.
Growth of Saccharomyces cerevisiae on poor nitrogen sources such as allantoin or proline was totally inhibited by addition of a non-degradable basic amino acid to the medium. Cells treated with lysine contained greatly reduced quantities of histidine and arginine. Conversely, lysine and histidine were severely reduced in arginase-deficient cells treated with arginine. When all three basic amino acids were present in the culture medium, growth was normal suggesting that synthesis of all three basic amino acids was decreased by an excess of any one of them. Inhibition of growth was accompanied by a fivefold increase in the observed ratio of budded to unbudded cells. These morphological changes suggested that DNA synthesis was inhibited. Consistent with this suggestion, addition of a basic amino acid to the culture medium substantially reduced the ability of the cells to incorporate [14C]uracil into alkali-resistant, trichloroacetic acid-precipitable material. RNA and protein synthesis, although decreased, were less sensitive to the effects of such additions.
在培养基中添加不可降解的碱性氨基酸会完全抑制酿酒酵母在如尿囊素或脯氨酸等劣质氮源上的生长。用赖氨酸处理的细胞中组氨酸和精氨酸的含量大幅降低。相反，在用精氨酸处理的精氨酸酶缺陷型细胞中，赖氨酸和组氨酸的含量严重减少。当培养基中同时存在这三种碱性氨基酸时，生长正常，这表明任何一种碱性氨基酸过量都会降低这三种碱性氨基酸的合成。生长抑制伴随着出芽细胞与未出芽细胞的观察比例增加五倍。这些形态变化表明DNA合成受到抑制。与此推测一致的是，向培养基中添加碱性氨基酸会大幅降低细胞将[14C]尿嘧啶掺入耐碱的三氯乙酸沉淀物质中的能力。RNA和蛋白质合成虽然减少，但对此类添加物的影响不太敏感。
