Department of Biological Sciences, Florida Atlantic University, Boca Raton, FL 33431, United States.
Exp Gerontol. 2011 Oct;46(10):827-32. doi: 10.1016/j.exger.2011.07.002. Epub 2011 Jul 26.
We have previously shown that copper supplementation extends the replicative life span of Saccharomyces cerevisiae when grown under conditions forcing cells to respire. We now show that copper's effect on life span is through Fet3p, a copper containing enzyme responsible for high affinity transport of iron into yeast cells. Life span extensions can also be obtained by supplementing the growth medium with 1mM ferric chloride. Extension by high iron levels is still dependent on the presence of Fet3p. Life span extension by iron or copper requires growth on media containing glycerol as the sole carbon source, which forces yeast to respire. Yeast grown on glucose containing media supplemented with iron show no extension of life span. The iron associated with cells grown in media supplemented with copper or iron is 1.4-1.8 times that of cells grown without copper or iron supplementation. As with copper supplementation, iron supplementation partially rescues the life span of superoxide dismutase mutants. Cells grown with copper supplementation display decreased production of superoxide as measured by dihydroethidium staining.
我们之前的研究表明，在迫使细胞呼吸的条件下，铜补充剂可以延长酿酒酵母的复制寿命。现在我们发现，铜对寿命的影响是通过 Fet3p 实现的，Fet3p 是一种含有铜的酶，负责将铁高亲和力地运输到酵母细胞中。在生长培养基中补充 1mM 三氯化铁也可以延长寿命。高铁水平的延长仍然依赖于 Fet3p 的存在。铁或铜的寿命延长需要在含有甘油作为唯一碳源的培养基上生长，这迫使酵母进行呼吸。在含有葡萄糖的培养基中补充铁的酵母生长不会延长寿命。与在补充铜或铁的培养基中生长的细胞相比，与细胞结合的铁是 1.4-1.8 倍。与铜补充一样，铁补充部分挽救了超氧化物歧化酶突变体的寿命。通过二氢乙啶染色测量，用铜补充剂培养的细胞显示出超氧化物生成减少。
