Svensson Malin J, Larsson Jan
UCMP, Umeå University, Umeå, Sweden.
Hereditas. 2007 Mar;144(1):25-32. doi: 10.1111/j.2007.0018-0661.01990.x.
Thioredoxins are proteins that have thiol-reducing activity and a characteristic conserved active site (WCGPC). They have several documented functions, e.g. roles in defences against oxidative stress and as electron donors for ribonucleotide-reductase. In Drosophila melanogaster there are three "classical" thioredoxins with the conserved active site: deadhead, ThioredoxinT and Thioredoxin-2. Here, we report the creation of null-mutations in the Thioredoxin-2 (Trx-2) gene. Characterization of two Trx-2 mutants indicated that Trx-2 affects the lifespan of D. melanogaster, and is involved in the organism's oxidative stress protection system. We found that the mutants have a shorter lifespan than wild-type flies, and thioredoxin double mutant flies showed lower tolerance to oxidative stress than wild-type flies, while flies carrying multiple copies of a Trx-2 rescue construct showed higher tolerance. These findings suggest that Trx-2 has modest or redundant functions in Drosophila physiology under unstressed conditions, but could be important during times of environmental stress.
硫氧还蛋白是具有硫醇还原活性和特征性保守活性位点（WCGPC）的蛋白质。它们具有多种已被记录的功能，例如在抵御氧化应激中发挥作用以及作为核糖核苷酸还原酶的电子供体。在黑腹果蝇中，有三种具有保守活性位点的“经典”硫氧还蛋白：deadhead、硫氧还蛋白T和硫氧还蛋白-2。在此，我们报告了硫氧还蛋白-2（Trx-2）基因无效突变的产生。对两个Trx-2突变体的表征表明，Trx-2影响黑腹果蝇的寿命，并参与生物体的氧化应激保护系统。我们发现，突变体的寿命比野生型果蝇短，硫氧还蛋白双突变果蝇对氧化应激的耐受性低于野生型果蝇，而携带多个Trx-2拯救构建体拷贝的果蝇表现出更高的耐受性。这些发现表明，Trx-2在无应激条件下的果蝇生理学中具有适度或冗余的功能，但在环境应激时期可能很重要。
