The alternative oxidase AOX does not rescue the phenotype of tko25t mutant flies.
The alternative oxidase AOX does not rescue the phenotype of tko25t mutant flies.
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DOI：
10.1534/g3.114.013946
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发表时间：
2014-08-21
期刊：
影响因子：
--
通讯作者：
Jacobs HT
中科院分区：
文献类型：
--
作者：
Kemppainen KK;Kemppainen E;Jacobs HT
编码有丝分裂原蛋白S12的果蝇基因的点突变[技术性基因敲除25t(Tko25t)]会产生一种发育迟缓和强烈敏感的表型。Tko25t作为人类线粒体疾病的动物模型已被广泛研究，这些疾病与线粒体蛋白合成不足以及由此导致的多个呼吸链缺陷有关。已有研究表明，在果蝇中转基因表达来源于大黄蜂的交替氧化酶(AOX)可以减轻呼吸链抑制剂的毒性，挽救与细胞色素氧化酶缺乏症相关的突变和敲除表型。因此，我们使用GeneSwitch系统在发育的不同时间激活AOX的表达，以检验AOX的表达是否能够补偿tko25t的突变表型。在整个发育过程中，AOX的表达并不能缓解tko25t的发育延迟。AOX在羽化后1d或在整个发育过程中持续表达，对Tko25t成虫的爆炸敏感性没有影响，30d以上的成虫继续表达也没有改善其表型。相反，酵母替代NADH脱氢酶Ndi1的转基因表达与tko25t合成的半致死，当与AOX和tko25t结合时是致命的。我们的结论是，AOX不能挽救tko25t，突变表型不仅仅是由于呼吸链中电子流动的限制，而是更复杂的代谢缺陷。因此，AOX未来用于线粒体翻译障碍的治疗价值可能有限。
A point mutation [technical knockout25t (tko25t)] in the Drosophila gene coding for mitoribosomal protein S12 generates a phenotype of developmental delay and bang sensitivity. tko25t has been intensively studied as an animal model for human mitochondrial diseases associated with deficiency of mitochondrial protein synthesis and consequent multiple respiratory chain defects. Transgenic expression in Drosophila of the alternative oxidase (AOX) derived from Ciona intestinalis has previously been shown to mitigate the toxicity of respiratory chain inhibitors and to rescue mutant and knockdown phenotypes associated with cytochrome oxidase deficiency. We therefore tested whether AOX expression could compensate the mutant phenotype of tko25t using the GeneSwitch system to activate expression at different times in development. The developmental delay of tko25t was not mitigated by expression of AOX throughout development. AOX expression for 1 d after eclosion, or continuously throughout development, had no effect on the bang sensitivity of tko25t adults, and continued expression in adults older than 30 d also produced no amelioration of the phenotype. In contrast, transgenic expression of the yeast alternative NADH dehydrogenase Ndi1 was synthetically semi-lethal with tko25t and was lethal when combined with both AOX and tko25t. We conclude that AOX does not rescue tko25t and that the mutant phenotype is not solely due to limitations on electron flow in the respiratory chain, but rather to a more complex metabolic defect. The future therapeutic use of AOX in disorders of mitochondrial translation may thus be of limited value.
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DOI：
10.1146/annurev.pathol.3.121806.151529
发表时间：
2009
期刊：
Annual review of pathology
影响因子：
--
作者：
Lu B;Vogel H
通讯作者：
Vogel H
DOI：
10.1016/j.bbamcr.2010.09.019
发表时间：
2011-07
期刊：
Biochimica et biophysica acta
影响因子：
--
作者：
Scarpulla RC
通讯作者：
Scarpulla RC
影响因子：
3.5
作者：
Humphrey, Dickon M.;Parsons, Richard B.;Hirth, Frank
通讯作者：
Hirth, Frank
影响因子：
1.9
作者：
Iovchev, M;Kodrov, P;Semenov, EP
通讯作者：
Semenov, EP
影响因子：
3.3
作者：
Parker, Louise;Padilla, Miguel;Tanouye, Mark A.
通讯作者：
Tanouye, Mark A.