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.

2025-08-15 | MSV000098838 | MassIVE

Transcriptional response of the marine pennate diatom Phaeodactylum tricornutum to Fe limitation

Project description:Diatoms, which are responsible for up to 40% of the 45 to 50 billion metric tons of organic carbon production each year in the sea, are particularly sensitive to Fe stress. Here we describe the transcriptional response of the pennate diatom Phaeodactylum tricornutum to Fe limitation using a partial genome microarray based on EST and genome sequence data. Processes carried out by components rich in Fe, such as photosynthesis, mitochondrial electron transport and nitrate assimilation are down-regulated to cope with the reduced cellular iron quota. This retrenchment is compensated by nitrogen (N) and carbon (C) reallocation from protein and storage carbohydrate degradation, adaptations to chlorophyll biosynthesis and pigment metabolism, removal of excess electron s by mitochondrial alternative oxidase (AOX), augmented Fe-independent oxidative stress responses, and sensitized iron capture mechanisms. Keywords: Marine phytoplankton, pinnate diatom Wild-type Phaeodactylum tricornutum was grown under Fe replete (10,000 nM) and Fe limiting (5nM) conditions. Partial genome gene expression analysis of iron-inducible genes was conducted using a two-color competitive hybridization microarray.

2010-05-27 | E-GEOD-8675 | biostudies-arrayexpress

kaAplPall

Project description:Aplidium pallidum (red sea pork)

| PRJEB81190 | ENA

kaAplTurb

Project description:Aplidium turbinatum (a colonial sea squirt)

| PRJEB45189 | ENA

E-GEOD-55187

Project description:Partial phenotypic rescue of the Sesb1 mitochondrial ANT1 disease model in Drosophila

2015-08-04 | E-GEOD-55187 | ExpressionAtlas

kaAplTurb1

Project description:Aplidium turbinatum (a colonial sea squirt) genome assembly, kaAplTurb1