18] In vivo labeling and analysis of human mitochondrial translation products

Abstract

Publisher Summary This chapter describes methods utilized in the laboratory for the study of mitochondrial protein synthesis in vivo in human cells in culture. These methods can easily be applied to other mammalian cells. The analysis of mitochondrial translation products has proved to be useful for the study of mitochondrial DNA (mtDNA) mutations causing diseases in humans or isolated in cultured cell systems. Among the mutants analyzed in this way, there are some that exhibit a decreased overall protein synthesis rate, some that synthesize additional, abnormal polypeptides, because of premature termination or the presence of deletions, and some that do not synthesize one or another given polypeptide due to frameshift mutations. As of the simplicity of the mammalian mitochondrial genetic system, with only 13 protein-coding genes, and because of the high signal-to-noise ratio in the labeled translation products, in vivo labeling and analysis of the mitochondrial translation products provide a very powerful tool for the dissection of the molecular pathogenetic mechanisms of mtDNA mutations affecting the translation apparatus.