Yamasaki Y, Ichihara A
J Biochem. 1977 Feb;81(2):461-5. doi: 10.1093/oxfordjournals.jbchem.a131479.
Induction of ornithine decarboxylase [EC 4.1.1.17] (ODC) in mouse L cells by components of the culture medium was investigated. It was found that further addition of amino acid mixture, but not of calf serum, to confluent cells of 5 day culture induced ODC and that this induction was accelerated by actinactinomycin D. In salt solution, addition of either amino acids or serum alone did not cause full induction, but addition of both together did. This induction, in contrast, was inhibited by actinomycin D. Induction by insulin, but not by cyclic AMP, was enhanced by a higher concentration of amino acids. These results can be explained by supposing that in non-growing cells there is stable RNA which is involved in ODC induction, possibly mRNA of ODC, and that the observed induction is caused by inhibition of enzyme degradation and accelerated translation, while in growing cells this RNA is unstable and ODC induction is controlled at the level of transcription.
研究了培养基成分对小鼠L细胞中鸟氨酸脱羧酶EC 4.1.1.17的诱导作用。发现向培养5天的汇合细胞中进一步添加氨基酸混合物而非小牛血清可诱导ODC，且放线菌素D可加速这种诱导。在盐溶液中，单独添加氨基酸或血清均不能引起完全诱导，但两者一起添加则可。相比之下，这种诱导被放线菌素D抑制。较高浓度的氨基酸可增强胰岛素而非环磷酸腺苷的诱导作用。这些结果可以通过以下假设来解释：在非生长细胞中存在参与ODC诱导的稳定RNA，可能是ODC的信使核糖核酸，观察到的诱导是由酶降解的抑制和翻译加速引起的，而在生长细胞中这种RNA不稳定，ODC诱导在转录水平受到控制。
