Project description:Saccharomyces cerevisiae is an excellent microorganism for industrial succinic acid production, but high succinic acid concentration will inhibit the growth of Saccharomyces cerevisiae then reduce the production of succinic acid. Through analysis the transcriptomic data of Saccharomyces cerevisiae with different genetic backgrounds under different succinic acid stress, we hope to find the response mechanism of Saccharomyces cerevisiae to succinic acid.
Project description:Rsp5 is an essential and multi-functional E3 ubiquitin ligase in Saccharomyces cerevisiae. We previously isolated the Ala401Glu rsp5 mutant, which is hypersensitive to various stresses. To understand the function of Rsp5 in stress responses, suppressor genes whose overexpression allows rsp5A401E cells to grow at high temperature were screened. The KIN28 and POG1 genes, encoding a subunit of the transcription factor TFIIH and a putative transcriptional activator, respectively, were identified as multicopy suppressors of not only high temperature but also LiCl stresses. The overexpression of Kin28 and Pog1 in rsp5A401E cells caused an increase in the transcriptional level of some stress proteins when exposed to temperature up-shift. DNA microarray analysis under LiCl stress revealed that the transcriptional level of some proteasome components was increased in rsp5A401E cells overexpressing Kin28 or Pog1. These results suggest that the overexpression of Kin28 and Pog1 enhances the protein refolding and degradation pathways in rsp5A401E cells. Keywords: mutant analysis, stress response
Project description:Rsp5 is an essential and multi-functional E3 ubiquitin ligase in Saccharomyces cerevisiae. We previously isolated the Ala401Glu rsp5 mutant, which is hypersensitive to various stresses. To understand the function of Rsp5 in stress responses, suppressor genes whose overexpression allows rsp5A401E cells to grow at high temperature were screened. The KIN28 and POG1 genes, encoding a subunit of the transcription factor TFIIH and a putative transcriptional activator, respectively, were identified as multicopy suppressors of not only high temperature but also LiCl stresses. The overexpression of Kin28 and Pog1 in rsp5A401E cells caused an increase in the transcriptional level of some stress proteins when exposed to temperature up-shift. DNA microarray analysis under LiCl stress revealed that the transcriptional level of some proteasome components was increased in rsp5A401E cells overexpressing Kin28 or Pog1. These results suggest that the overexpression of Kin28 and Pog1 enhances the protein refolding and degradation pathways in rsp5A401E cells. Experiment Overall Design: Total RNA from S. cerevisiae was isolated by the method of Köhrer and Domdey (1991). Poly A mRNA was enriched from total RNA by Oligotex dT30 mRNA purification kit (Takara Bio). The Affimetrix yeast genome S98 arrays (YGS98 GeneChip, Affymetrix, Santa Clara, CA) were used as DNA microarray in this study. The biotinyated cRNA (15 μg) probe was hybridized to DNA microarray at 45°C for 18 h according to Affymetrix userâs manual. Experiment Overall Design: The washing and staining of arrays were performed using the GeneChip Fluidics Station 400. Experiment Overall Design: The scanning of arrays was carried out using the GeneArray scanner (Agilent technologies, Palto Alto, CA).
Project description:Industrial bioethanol production may involve a low pH environment,improving the tolerance of S. cerevisiae to a low pH environment caused by inorganic acids may be of industrial importance to control bacterial contamination, increase ethanol yield and reduce production cost. Through analysis the transcriptomic data of Saccharomyces cerevisiae with different ploidy under low pH stress, we hope to find the tolerance mechanism of Saccharomyces cerevisiae to low pH.
Project description:TFIIH is a 10-protein complex that is conserved through out eukaryotes. TFIIH has two primary cellular functions: transcription initiation and nucleotide excision repair (NER). In transcription initiation, TFIIH acts as a structural scaffold, phosphorylates the RNA polymerase II (pol II) C-terminal domain (CTD) and translocates promoter DNA through the pol II active site to facilitate start site selection. In NER, again is a structural scaffold, opens a bubble around damaged DNA and scans the damaged strand for bulky lesions. In yeast (Saccharomyces cerevisiae), TFIIH is composed of the two helicases Ssl2 and Rad3, the scaffolding subunits Tfb1, Tfb2, Tfb4 and Ssl1 and the kinase subunits Kin28, Ccl1 and Tfb3.
Project description:TFIIH is a 10-protein complex that is conserved throughout eukaryotes. TFIIH has two primary cellular functions: transcription initiation and nucleotide excision repair (NER). NER in eukaryotes begins by recognition of a bulky lesion by the obligate dimer Rad4-Rad23. This is followed closely by the recruitment of TFIIH which is a structural scaffold, opens a bubble around damaged DNA and scans the damaged strand for bulky lesions. This facilitates the recruitment of two exonucleases which excise the damages strand before an undamaged complement is synthesize. In yeast (Saccharomyces cerevisiae), TFIIH is composed of the two helicases Ssl2 and Rad3, the scaffolding subunits Tfb1, Tfb2, Tfb4 and Ssl1 and the kinase subunits Kin28, Ccl1 and Tfb3, though these later 3 are dispensable for NER.
Project description:The initial step of RNA polymerase II (Pol II) transcription involves a large number of transcription factors and arises at multiple sites within most promoters. TFIIH is an essential, multi-subunit transcription factor that assembles on promoter DNA with Pol II and five other general transcription factors (GTFs) to form a pre-initiation complex (PIC) for basal transcription. During transcription initiation, TFIIH melts promoter DNA through the ATPase activity of its Ssl2 subunit. In the model eukaryote Saccharomyces cerevisiae, after DNA melting, Pol II scans downstream for usable transcription start sites (TSSs). To understand the function of Ssl2/TFIIH in promoter scanning and TSS selection, we identified novel alleles of SSL2 in genetic screens for mutants defective in TSS distribution that may potentially arise from altered scanning. Consistent with this notion, these ssl2 alleles alter scanning in ways that are distinct from how changes to the Pol II active site alter scanning and this difference is observed genome-wide. Our investigations support two major pathways in controlling promoter scanning and TSS selection, one controlling the efficiency of initiation through Pol II activity or factors regulating Pol II activity; another network appears to control the processivity of scanning by Ssl2/TFIIH.