Integrative Omics reveals changes in the cellular landscape of yeast without peroxisomes

Peroxisomes are organelles that are crucial for cellular metabolism. However, these organelles play also important roles in non-metabolic processes, such as signalling. To uncover the consequences of peroxisome deficiency, we compared two extremes, namely Saccharomyces cerevisiae wild-type and pex3 cells, which lack functional peroxisomes, employing transcriptomics and quantitative proteomics technology. Cells were grown on acetate, a carbon source that involves peroxisomal enzymes of the glyoxylate cycle and does not repress peroxisomal proteins. Transcripts of peroxisomal β-oxidation genes and the corresponding proteins were enhanced in pex3 cells. Peroxisome-deficiency also caused reduced levels of membrane bound peroxins, while the soluble receptors Pex5 and Pex7 were enhanced at the protein level. In addition, we observed alterations in non-peroxisomal transcripts and proteins, especially mitochondrial proteins involved in respiration or import processes. Our results not only reveal the impact of the absence of peroxisomes in yeast, but also represent a rich resource of candidate genes/proteins that are relevant in peroxisome biology. Deletion of pex3 obstruct formation of functional peroxisomes. Will deletion of pex3 have an effect on the overall transcriptome? We compared transcriptomes of S. cerevisiae BY4741 wild type as control strain to the S. cerevisiae BY4741 pex3 deletion strain. These strains were cultivated on acetate because it derepresses the expression of many peroxisomal proteins.