Project description:Saccharomyces cerevisiae has been used as a secretion host for production of various products, including pharmaceuticals. However, few antibody molecules have been functionally expressed in S. cerevisiae due to the incompatible surface glycosylation. Our laboratory previously isolated a group of yeast mutant strains with different α-amylase secretory capacities, and these evolved strains have showed advantages for production of some heterologous proteins. However, it is not known whether these secretory strains are generally suitable for pharmaceutical protein production. Here, three non-glycosylated antibody fragments with different configurations (Ran-Fab fragment Ranibizumab, Pex-the scFv peptide Pexelizumab, and Nan-a single V-type domain) were successfully expressed and secreted in three background strains with different secretory capacities, including HA (wild type), MA (evolved strain), and LA (evolved strain). However, the secretion of Ran and Nan were positively correlated with the strains’ secretory capacity, while Pex was most efficiently secreted in the parental strain. Therefore, transcriptional analysis was performed to explore the fundamental changes triggered by the expression of the different pharmaceutical proteins in these selected yeast strains.
Project description:We have employed whole genome microarray expression profiling as a discovery platform to identify genes implicated in the resistance to cobalt in Saccharomyces cerevisiae. The evolved strains and the wild type were harvested in exponential phase
Project description:The budding yeast, Saccharomyces cerevisiae, has emerged as an archetype of eukaryotic cell biology. Here we show that S. cerevisiae is also a model for the evolution of cooperative behavior by revisiting flocculation, a self-adherence phenotype lacking in most laboratory strains. Expression of the gene FLO1 in the laboratory strain S288C restores flocculation, an altered physiological state, reminiscent of bacterial biofilms. Flocculation protects the FLO1-expressing cells from multiple stresses, including antimicrobials and ethanol. Furthermore, FLO1+ cells avoid exploitation by non-expressing flo1 cells by self/non-self recognition: FLO1+ cells preferentially stick to one another, regardless of genetic relatedness across the rest of the genome. Flocculation, therefore, is driven by one of a few known â??green beard genesâ??, which direct cooperation towards other carriers of the same gene. Moreover, FLO1 is highly variable among strains both in expression and in sequence, suggesting that flocculation in S. cerevisiae is a dynamic, rapidly-evolving social trait. This dataset contains raw transcriptome data of flocculating cells (that express FLO1 driven by the GAL1 promoter) and non-flocculating cells (that do not express FLO1). Experiment Overall Design: Cultures of flocculating and non-flocculating cells were grown for 24 hours in YPGal medium. Subsequently, RNA was isolated from these cultures, converted into cDNA and analyzed using commercially available Afymetrix S98 arrays. For each culture, two biological replicates were analyzed.
Project description:We have employed whole genome microarray expression profiling as a discovery platform to identify genes implicated in the resistance to cobalt in Saccharomyces cerevisiae. The evolved strains and the wild type were harvested in exponential phase WT (CEN.PK), the evolved strain (CI25E) and the evolved strain delta Cot1 harvested in exponential phase (DO 600nm=3) ; three independant replicate for each.
