Influence of metallothionein-1 localization on its function
Influence of metallothionein-1 localization on its function
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DOI：
10.1042/0264-6021:3550473
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发表时间：
2001-04-15
影响因子：
4.1
通讯作者：
Wallace, HM
中科院分区：
文献类型：
--
作者：
Levadoux-Martin, M;Hesketh, JE;Wallace, HM
金属硫蛋白（MT）在金属代谢中起着重要作用，也可以保护DNA免受氧化损伤。MT蛋白定位于S期细胞核内。编码MT-1同种型的mRNA具有核周定位，并且与细胞骨架相关;由于3 ′-非翻译区（3 ′-UTR）内的信号，这种靶向促进MT-1在S期期间的核定位[Levadoux，Mahon，Beattie，Wallace和Hesketh（1999）J.Biol.Chem.274，34961-34966]。使用用3 '-UTR不同的MT基因构建体转染的细胞，研究了MT蛋白在细胞核中的作用。用完整MT基因（MTMT细胞）或MT 5 '-UTR和与谷胱甘肽过氧化物酶3'-UTR连接的编码区（MTGSH细胞）转染中国仓鼠卵巢细胞。暴露于氧化应激和化学试剂后的细胞存活率在表达天然MT基因的细胞中高于MT定位被破坏的细胞或未转染的细胞。此外，MTMT细胞表现出较少的DNA损伤比MTGSH细胞在响应过氧化氢或诱变剂。经紫外线或诱变剂照射后，MTMT细胞表现出较少的凋亡比MTCSH细胞，通过DNA片段化和流式细胞术评估。这些数据表明，MT mRNA的核周定位是重要的MT的功能，对DNA损伤和细胞凋亡诱导的外部压力的保护作用。
Metallothioneins (MTs) have a major role to play in metal metabolism, and may also protect DNA against oxidative damage. MT protein has been found localized in the nucleus during S-phase. The mRNA encoding the MT-1 isoform has a perinuclear localization, and is associated with the cytoskeleton; this targeting, due to signals within the 3'-untranslated region (3'-UTR), facilitates nuclear localization of MT-I during S-phase [Levadoux, Mahon, Beattie, Wallace and Hesketh (1999) J. Biol. Chem. 274, 34961-34966]. Using cells transfected with MT gene constructs differing in their 3'-UTRs, the role of MT protein in the nucleus has been studied. Chinese hamster ovary cells were transfected with either the full MT gene (MTMT cells) or with the MT 5'-UTR and coding region linked to the 3'-UTR of glutathione peroxidase (MTGSH cells). Cell survival following exposure to oxidative stress and chemical agents was higher in cells expressing the native MT gene than in cells where MT localization was disrupted, or in untransfected cells. Also, MTMT cells showed less DNA damage than MTGSH cells in response to either hydrogen peroxide or mutagen. After exposure to UV light or mutagen, MTMT cells showed less apoptosis than MTCSH cells, as assessed by DNA fragmentation and flow cytometry. The data indicate that the perinuclear localization of MT mRNA is important for the function of MT in a protective role against DNA damage and apoptosis induced by external stress.