Mechanisms of mitochondrial translational regulation

The mitochondrial oxidative phosphorylation system is formed by multimeric enzymes. In the yeast Saccharomyces cerevisiae, the bc₁ complex, cytochrome c oxidase and the F₁F_O ATP synthase contain subunits of dual genetic origin. It has been recently established that key subunits of these enzymes, translated on mitochondrial ribosomes, are the subjects of assembly-dependent translational regulation. This type of control of gene expression plays a pivotal role in optimizing the biogenesis of mitochondrial respiratory membranes by coordinating protein synthesis and complex assembly and by limiting the accumulation of potentially harmful assembly intermediates. Here, the author will discuss the mechanisms governing translational regulation in yeast mitochondria in the light of the most recent discoveries in the field.