Proteasome regulation of petite-negativity in fission yeast.
Mitochondria carry out essential functions in eukaryotic cells. The mitochondrial genome encodes factors critical to support oxidative phosphorylation and mitochondrial protein import necessary for these functions. However, organisms like budding yeast can readily lose their mitochondrial genome, yielding respiration-deficient petite mutants. The fission yeast Schizosaccharomyces pombe is petite-negative, but some nuclear mutations enable the loss of its mitochondrial genome.
ptp1-1 is a partial loss of function mutation of the proteasome that enables growth of cells devoid of mitochondrial DNA through a mechanism that is independent of mitochondrial membrane potential rescue and associated with proteasome-dependent regulation of mitochondrial protein import precursors and the oxidative stress response.
Amberg KL, Hao L, Cranz-Mileva S, Zaratiegui M