REGULATION OF POLYAMINE TRANSPORT IN CHINESE HAMSTER OVARY CELLS
REGULATION OF POLYAMINE TRANSPORT IN CHINESE HAMSTER OVARY CELLS
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DOI：
10.1002/jcp.1041430309
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发表时间：
1990-06-01
影响因子：
5.6
通讯作者：
PEGG, AE
中科院分区：
文献类型：
--
作者：
BYERS, TL;PEGG, AE
以中国仓鼠卵巢(CHO)对照细胞和缺乏鸟氨酸脱羧酶活性的突变CHO细胞(CHODC-)为研究对象，研究CHO细胞对多胺摄取的调节作用。研究发现，负责这种摄取的运输系统受细胞内多胺水平的调节，这种调节负责在极端条件下维持细胞内的生理水平，例如多胺被剥夺或暴露在外源性多胺中。通过用α-二氟甲基鸟氨酸抑制CHO细胞的鸟氨酸脱羧酶或通过CHODC-细胞的多胺饥饿而产生的多胺含量的减少，多胺的转运活性得到了增强。外源多胺的供应导致细胞内多胺含量迅速和大幅增加，随后多胺转运活性降低。在摄取活性下降后不久，细胞内多胺水平下降到接近控制值。在外源性多胺存在的情况下生长的细胞将细胞内多胺水平维持在与对照细胞相似的值。蛋白质合成对于响应多胺耗竭而增加转运是必要的，但似乎对减少多胺转运没有作用。双乙基多胺类似物在调节多胺转运方面与多胺相似，但这一过程对亚精胺类似物甲基乙醛双(鸟苷酸)的调节相对不敏感，亚精胺类似物通过这种运输系统进入细胞并积累到非常高的水平。
Control Chinese hamster ovary (CHO) cells and mutant CHO cells lacking ornithine decarboxylase activity (CHODC-) were used to study the regulation of polyamine uptake. It was found that the transport system responsible for this uptake was regulated by intracellular polyamine levels and that this regulation was responsible for the maintenance of physiological intracellular levels under extreme conditions such as polyamine deprivation or exposure to exogenous polyamines. Polyamine transport activity was enhanced by decreases in polyamine content produced either by inhibition of ornithine decarboxylase with .alpha.-difluoromethylornithine in CHO cells or via polyamine starvation of CHODC- cells. The provision of exogenous polyamines resulted in rapid and large increases in intracellular polyamine content followed by decreased polyamine transport activity. Soon after this decrease in uptake activity, intracellular polyamine levels then fell to near control values. Cells grown in the presence of exogenous polyamines maintained intracellular polyamine levels at values similar to those of control cells. Protein synthesis was necessary for the increase in transport in response to polyamine depletion, but appeared to play no role in decreasing polyamine transport. Bis(ethyl) polyamine analogues mimicked polyamines in the regulation of polyamine transport but this process was relatively insensitive to regulation by methylglyoxal bis(guanylhydrazone), a spermidine analogue known to enter cells via this transport system and to accumulate to very high levels.