Project description:Sfp1p is known to form the [ISP+] prion in Saccharomyces cerevisiae. Interestingly enough, the consequences and phenotypes of Sfp1p prionization and its absence are quite different. In order to understand the origin of this difference, we compared transcription profiles of an [ISP+], sfp1delta strains against the control strain (SFP1 [isp-]).
Project description:Sfp1p is known to form the [ISP+] prion in Saccharomyces cerevisiae. Interestingly enough, the consequences and phenotypes of Sfp1p prionization and its absence are quite different. In order to understand the origin of this difference, we compared transcription profiles of an [ISP+], sfp1delta strains against the control strain (SFP1 [isp-]). 3 strains (an [ISP+], [isp-] and sfp1delta derivative of 25-25-2V-P3982, Peterhoff genetic collection), each in quadruplicate (4 biological replicates).
Project description:In Saccharomyces cerevisiae growth, size control and cell cycle progression are strictly coordinated and regulated according to the nutritional conditions. In particular, ribosome biogenesis appears a key event in this regulatory network. SFP1 encodes a zinc-finger protein promoting the transcription of a large cluster of genes involved in ribosome biogenesis. It has been suggested that Sfp1 is a cell size modulator acting at Start. To better study the regulatory role of Sfp1 and its putative involvement in cell size and cycle control, we analysed the behaviour of an sfp1 null mutant strain and of an isogenic reference strain growing in chemostat cultures. This approach allowed us to analyze both strains at the same specific growth rate, thus eliminating the secondary effects due to the slow growing phenotype that the sfp1 null mutant shows in shake flask. We studied glucose(anaerobic)- and ethanol(aerobic)-limited cultures, as paradigms of two different metabolic states. Major alterations of the transcriptional profile were observed during growth on glucose, while no significant differences were observed when comparing ethanol growing cultures. In particular, in the former growth condition, Sfp1 appears involved in the control of ribosome biogenesis but not of ribosomal protein gene expression. Experiment Overall Design: The reference S. cerevisiae strain CEN.PK113.7D and the isogenic sfp1 null mutant were grown in chemostat cultures under ethanol(aerobic)- and glucose(anaerobic)- limitation. The dilution rate was set at 0.10 h-1 and 0.05 h-1 for ethanol- and glucose-limited cultures, respectively. A genome-wide transcriptional analysis was performed for the reference and the sfp1 null mutant strains for each growth condition. All data presented in this work were derived from three independent chemostat cultures (12 samples in total were analysed).
Project description:Coordinated increase in cellular RNA and protein content induced by overexpression of Far1, a cyclin dependent kinase inhibitor, involves large transcriptional reprogramming and requires the Sfp1 protein.
