The synthesis of mRNA in isolated mitochondria can be maintained for several hours and is inhibited by high levels of ATP
The synthesis of mRNA in isolated mitochondria can be maintained for several hours and is inhibited by high levels of ATP
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DOI：
10.1111/j.1432-1033.1996.0601p.x
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发表时间：
1996-05-01
期刊：
影响因子：
--
通讯作者：
Montoya, J
中科院分区：
文献类型：
--
作者：
Enriquez, JA;FernandezSilva, P;Montoya, J
一种新的细胞器内RNA合成系统研究了线粒体RNA的合成和成熟依赖于核质因子的供应。我们发现，在分离的线粒体中，线粒体DNA转录可以保持几个小时。对单个线粒体RNA物种的分析表明：rRNA前体的加工和成熟rRNAs的稳定性在短时间的孵育后受到严重损害，但转录本身并不严重，这表明这些过程强烈依赖线粒体与核质间的相互作用；导致线粒体mRNAs合成、加工和周转的事件不需要持续供应由线粒体过量积累的核质因子。此外，我们提出的证据表明，在细胞器和体外，高水平的ATP对线粒体RNA聚合酶活性都有抑制作用。因此，有人认为线粒体的mRNA合成可以根据线粒体内ATP水平的变化进行调节。这里和其他地方描述的线粒体mRNA合成的调节及其非常快速的周转[Gelfand，R.&Attardi，G.(1981)Mel.细胞生物。1,497-511]，这可能代表了一种机制，允许每个单独的线粒体调整其最佳的mRNA水平，从而调整其翻译能力，以回应当地的能量需求。
The dependence for the maintenance of the synthesis and maturation of mitochondrial RNA on the supply of nucleo-cytoplasmic factors has been investigated by a novel in organello RNA synthesis system. We found that mitochondrial DNA transcription can be maintained for several hours in isolated mitochondria. Analysis of the individual mitochondrial RNA species revealed that:the processing of the rRNA precursors and the stability of the mature rRNAs, but not the transcription itself, is severely impaired after short periods of incubation, indicating that these processes are strongly dependent on the mitochondrial interaction with the nucleo-cytoplasmic compartment; the events that lead to the synthesis, processing and turnover of the mitochondrial mRNAs do not require the continuous supply of nucleo-cytoplasmic factors, that are accumulated in excess by mitochondria. Furthermore, we present evidence indicating an inhibition of high ATP levels on the mitochondrial RNA polymerase activity, both in organello and in vitro. Consequently, it is proposed that mitochondrial mRNA synthesis can be regulated in response to changes in intramitochondrial ATP levels. This regulation of mitochondrial mRNA synthesis together with their very rapid turnover described here and elsewhere [Gelfand, R. & Attardi, G. (1981) Mel. Cell Biol. 1, 497-511], could represent a mechanism that would allow each individual mitochondrion to adjust its optimal levels of mRNA, and hence its translation capacity, in response to local energetic demands.