Price-Haughey J, Bonham K, Gedamu L
Biochim Biophys Acta. 1987 Feb 27;908(2):158-68. doi: 10.1016/0167-4781(87)90055-8.
We have investigated the regulation of metallothionein gene expression in two fish cell lines. Rainbow trout hepatoma (RTH) cells synthesized metallothionein in response to heavy metal exposure. The maximum level of metallothionein synthesis detected during zinc exposure was much greater than during cadmium exposure. The time-courses of metallothionein synthesis were different for the different metal inducers, suggesting that metallothionein may be differentially regulated by cadmium and zinc in these cells. The metal-induced synthesis of metallothionein was correlated with increased translational activity and accumulation of metallothionein-mRNA, suggesting that metallothionein may be regulated at the transcriptional and post-transcriptional levels in RTH cells. Chinook salmon embryo (CHSE) cells, unlike RTH cells, did not synthesize metallothionein or metallothionein-mRNA in response to heavy metal exposure. However, when these cells were treated with 5-azacytidine prior to heavy metal exposure, the synthesis of metallothionein was induced, suggesting that DNA methylation may play a role in metallothionein gene expression in fish.
我们研究了两种鱼类细胞系中金属硫蛋白基因表达的调控。虹鳟肝癌（RTH）细胞在暴露于重金属时会合成金属硫蛋白。锌暴露期间检测到的金属硫蛋白合成的最大水平远高于镉暴露期间。不同金属诱导剂的金属硫蛋白合成时间进程不同，这表明在这些细胞中金属硫蛋白可能受到镉和锌的差异调节。金属诱导的金属硫蛋白合成与翻译活性的增加和金属硫蛋白 - mRNA的积累相关，这表明金属硫蛋白可能在RTH细胞的转录和转录后水平受到调控。奇努克鲑鱼胚胎（CHSE）细胞与RTH细胞不同，在暴露于重金属时不会合成金属硫蛋白或金属硫蛋白 - mRNA。然而，当这些细胞在重金属暴露前用5 - 氮杂胞苷处理时，金属硫蛋白的合成被诱导，这表明DNA甲基化可能在鱼类金属硫蛋白基因表达中起作用。
