Inhibition of mitochondrial gene expression by antisense RNA of mitochondrial transcription factor A (mtTFA).

Mitochondrial transcription factor A (mtTFA) plays an important role in regulating the expression of mitochondrial genes. To gain a better understanding of the relationships between mitochondrial gene expression and mtTFA, the mtTFA gene was inserted into a mammalian expression vector, both in the sense orientation and in the antisense orientation. After construction, these plasmids were transfected into COS-7 cells. In antisense-transformed cells, the expression of the cytochrome c oxidase subunit I and subunit III genes encoded by mitochondrial DNA was inhibited and there was an accompanying reduction of the level of mtTFA protein. These results provide direct evidence that the expression of mitochondrial genes is under the control of mtTFA.