Project description:The intent of the experiment was to gather transcriptomic data from terminally differentiated cell types --spore, stalk, and cup cells-- in a simple multicellular model system, Dictyostelium discoideum, in order to characterize the cell-type specific gene expression patterns. Specifically, we dissociated and collected each cell type from the fruiting bodies of D. discoideum at 24 hours of development. We also collected exponentially growing vegetative cells of D. discoideum.
Project description:spaA is a Cud-type transcription factor that is essential for spore cell differentiation of Dictyostelium discoideum, a social amoeba. ChIP-seq was performed to identify spaA target genes.
Project description:Dictyostelium discoideum behavior depends on nutrients. When sufficient food is present these amoebae exist in a unicellular state (vegetative growth), but upon starvation they aggregate into a multicellular organism (developmental growth). For proteomics 30 minutes and eight hour cultures of D. discoideum under vegetative and starved growth conditions were compared by DIA-LFQ. This unique biology makes D. discoideum an ideal model for investigating how fundamental metabolism commands cell differentiation and function. We show here that reactive oxygen species (ROS), generated as a consequence of nutrient limitation, lead to the sequestration of the amino acid cysteine in the antioxidant glutathione, limiting the use of its sulfur atom for processes such as protein translation and FeS cluster-containing enzyme activity that contribute to mitochondrial metabolism and cellular proliferation. Such regulated sulfur sequestration maintains D. discoideum in a non-proliferating state that paves the way for multicellular development. This new mechanism of ROS signaling highlights oxygen and sulfur as simple, early evolutionary signaling molecules dictating cell fate, with implications for responses to nutrient fluctuations in higher eukaryotes.
