Mitochondrial Gene Expression and Dysfunction in Model Protozoa
Mitochondrial Gene Expression and Dysfunction in Model Protozoa
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DOI：
10.1007/978-3-642-22380-8_10
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发表时间：
2012-01-01
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影响因子：
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通讯作者：
Fisher, Paul R.
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文献类型：
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作者：
Barth, Christian;Kennedy, Luke A.;Fisher, Paul R.
原生动物线粒体基因组在大小、结构和基因组织方面极其多样化。原生动物线粒体基因表达在细胞黏菌盘基网柄菌（Dictyosteelicdiscoideum）中的研究最为广泛，所使用的各种技术包括北方杂交和引物延伸分析以鉴定线粒体转录物及其5′端，逆转录-聚合酶链反应以鉴定杂交检测不到的转录物，体外加帽以标记转录起始产生的转录物，迁移率变动分析，以确定蛋白质结合的DNA序列，并在细菌转录，以检查这些序列的功能。结果表明，56 kbD.在一些实施方案中，盘状体线粒体基因组从单个单向启动子转录，并且所得多顺反子转录物被共转录加工以产生成熟mRNA、rRNA和tRNA分子。为了比较，描述了哺乳动物和酵母线粒体中基因表达的显著特征。discoideum现在是一个已建立的模型系统，用于研究通过靶向基因破坏或通过敲低核编码线粒体蛋白的表达而产生的线粒体疾病。由于细胞内信号传导途径的慢性失调，包括能量敏感蛋白激酶AMP活化蛋白激酶（AMPK）的过度活跃，导致各种细胞病理学。
Protozoan mitochondrial genomes are extraordinarily diverse in size, structure and gene organisation. Protozoan mitochondrial gene expression has been studied most extensively in the cellular slime mould,Dictyostelium discoideum, using various techniques that include northern hybridization and primer extension analyses to identify mitochondrial transcripts and their 5′ ends, Reverse Transcription–Polymerase Chain Reactions to identify transcripts not detectable by hybridization, in vitro capping to label transcripts generated by transcription initiation, mobility shift assays to identify protein-binding DNA sequences and in bacterio transcription to examine the function of these sequences. The results show that the 56 kbD. discoideummitochondrial genome is transcribed from a single, unidirectional promoter and that the resulting polycistronic transcript is processed co-transcriptionally to produce mature mRNA, rRNA and tRNA molecules. For comparison, salient features of gene expression in mammalian and yeast mitochondria are described.D. discoideumis now an established model system for studying mitochondrial disease created by targeted gene disruption or by knocking down expression of nuclear-encoded mitochondrial proteins. Diverse cytopathologies ensue because of chronic dysregulation of intracellular signalling pathways, including hyperactivity of an energy-sensing protein kinase, AMP-activated Protein Kinase (AMPK).