Protein release in a Saccharomyces cerevisiae mutant does not depend on mitochondrial genome integrity and function.

A mutant allele the of Saccharomyces cerevisiae NUD1 gene causes a thermosensitive phenotype of the yeast cells and increases release of proteins into the culture medium at the restrictive temperature (37 degrees C). The release of proteins does not depend on the process of oxidative phosphorylation, because protein release is not stopped in the presence of inhibitors of oxidative phosphorylation. NUD1 transcription is not under retrograde regulation. This type of transcriptional regulation depends on the nuclear Rtg transcription factors and on the integrity of the mitochondrial genome.