Proteasome regulation of petite-negativity in fission yeast
Ontology highlight
ABSTRACT: In this data set, fission yeast (Schizosaccharomyces pombe) are used to investigate petite-positive mutation ptp1-1 derived mitochondrial ubiquitin-dependent degradation.
Project description:Background: 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.
Results: Here, we characterize the classical petite-positive mutation ptp1-1 as a loss of function allele of the proteasome 19S regulatory subunit component mts4/rpn1, involved in the ubiquitin-dependent degradation pathway. By comparison with another petite-enabling mutation in the g-subunit of the F1-ATPase, we show that ptp1-1 does not rescue mitochondrial membrane potential. Instead, the mutation results in increased levels of mitochondrial and cytoplasmic chaperones and an altered oxidative stress response.
Conclusions: 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.
Project description:His-Biotin-His Ubiquitin was overexpressed in various fission yeast (S. pombe) genetic backgrounds to identify ubiqutinated proteins. Normalizing to bait (ubiquitin) across samples provided insight into relative changes in ubiquitination with loss of deubiquitinases (DUBs), yielding putative DUB substrates.
Project description:This RNA-Seq analysis compares gene expression of the wild-type fission yeast (Schizosaccharomyces pombe) strain at various times after transfer to defined phosphate-replete ePMGT(+PO4) medium (2, 4, 8 HR) contrasting to the WT fission yeast S. pombe cells grown in phosphate-replete YES medium (0HR).
Project description:We report gene expression profiling in the fission yeast Schizosaccharomyces pombe. We performed high-throughput sequencing of RNA isolated from wild-type, erh1∆, and ccr4∆ strains. We find that many meiotic gene containing degradation sequence DSR are expressed in vegetative erh1∆, while these meiotic mRNAs do not increase in ccr4∆, indicating that Erh1 and Ccr4 target different set of genes during vegetative growth.
Project description:This RNA-Seq analysis compares gene expression of the pho7∆ fission yeast (Schizosaccharomyces pombe) strain prior to phosphate starvation (0 HR), i.e. in phosphate replete conditions, and at various times after phosphate starvation (4, 8, 12, 24, 36, and 48 HR) contrasting to the WT fission yeast S. pombe cells grown in phosphate replete conditions (WT 0HR)