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.

E-octadec-7-en-5-ynoic acid from the roots of Capparis zeylanica.

A new fatty acid, E-octadec-7-en-5-ynoic acid (1), has been isolated from chloroform extract of the roots of Capparis zeylanica. The structure of this compound was established primarily by 1D and 2D-NMR spectroscopy.

Protein overexport in a Saccharomyces cerevisiae mutant depends on mitochondrial genome integrity and function.

The wild-type yeast Saccharomyces cerevisiae (S. cerevisiae) is able to export less than 1 percent of the protein to be secreted. The reasons for retention of most of the secretory proteins on the cell surface of S. cerevisiae are unknown. Recently, temperature-sensitive (ts) mutants of S. cerevisiae showing an oversecretion phenotype were isolated. In order to study the influence of the mitochondrial genome status on protein export in yeast cells, we have isolated several types of respiratory impaired mitochondrial mutants of either the parental S. cerevisiae strain or their derivative ts protein-overexporting mutants. In this paper we demonstrate by quantitative analyses of exported proteins and by SDS-PAGE analysis that protein overexport in ts mutants requires mitochondrial genome integrity and function.