人类线粒体tRNA生物合成与线粒体疾病

线粒体是普遍存在于真核细胞中的一类细胞器.每个线粒体含有多个拷贝的闭合环状双链DNA. 人类线粒体DNA (mitochondrial DNA, mtDNA)共编码22种线粒体tRNA(mitochondrial tRNA，mt tRNA), 2种rRNA 及13种多肽.mt tRNA独特的结构特点决定了它们与具有典型三叶草结构的细胞质 tRNA不同.编码mt tRNA的基因突变频率较高，这可能是引起线粒体功能障碍的主要原因之一. 同时 ,这与很多病理现象相关.目前发现,大量与mt tRNA生物代谢和功能相关的核因子包括加工内切酶、 tRNA修饰酶和氨酰-tRNA合成酶.这些核因子的异常导致了疾病相关的tRNA致病突变.由此可见mt tRNA功能对于线粒体活性的重要性.

Human Mitochondrial tRNA Synthesis and Mitochondrial Diseases

Mitochondria are membrane-enclosed organelles found in eukaryotic cells to supply adenosine triphosphate (ATP) as the energy molecules. Mitochondrial DNA (mtDNA) is a circular molecule that codes 22 transfer RNAs, two ribosomal RNAs and 13 proteins. Mitochondrial tRNA is different from cytoplasmic tRNA and does not have a typical clover structure. The high-frequency mutations in mitochondrial tRNAs may cause mitochondrial dysfunction. Several nuclear factors, including processing endonuclease, tRNA modification enzymes and aminoacyl-tRNA synthetase, are involved in the biosynthesis and function of mitochondrial tRNA. Abnormalities of these nuclear factors associated with pathogenic mitochondrial tRNA mutations lead to diseases.