Beginning on page 401, Aiken Hobbs et al. describe the localization of the yeast mitochondrial protein Mmm1p, and propose that the protein is part of a complex that controls mitochondrial structure and DNA segregation. The results are consistent with a model in which a “mitoskeleton” might play a role in regulating mitochondrial activity and morphology.
Mmm1p was identified previously as a protein involved in mitochondrial structure, since the mitochondria of mmm1 mutants form large, spherical structures instead of the tubular reticular structures found in the periphery of wild-type yeast cells. In the new work, Aiken Hobbs et al. analyzed the localization of a Mmm1p-GFP fusion protein in vivo. The protein localizes to small, punctate structures on the outer membranes of mitochondria, adjacent to a subset of mitochondrial DNA (mtDNA) nucleoids. Temperature-sensitive Mmm1p mutants have a defect in mtDNA...
