Project description:Combinatorial promoter expression level estimation via cell sorting The purpose of this experiment was to determine the expression level of a library of synthetic promoters. The promoters were cloned in front of a GFP reporter and the resulting library transformed into yeast, sorted by FACS into six fluorescence bins, and the contents of the bins sequenced to determine the distribution of each promoter among each fluorescence bin. This was then used to calculate an expression level for each promoter with enough data.
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.
Project description:Combinatorial promoter expression level estimation via cell sorting The purpose of this experiment was to determine the expression level of a library of synthetic promoters. The promoters were cloned in front of a GFP reporter and the resulting library transformed into yeast, sorted by FACS into six fluorescence bins, and the contents of the bins sequenced to determine the distribution of each promoter among each fluorescence bin. This was then used to calculate an expression level for each promoter with enough data. The promoters were sorted into six bins and these, along with the unsorted library were barcoded and sequenced on a single lane of an Illumina HiSeq. The following Series supplementary files are provided: allPromoters.fsa.txt: the sequences of the promoters corresponding to the names in allPromoters.txt, not actually fasta format. Promoter sequence starts at pos 155 (0 indexed). allPromoters.txt: the names of all the promoters, corresponding to the sequences in allPromoters.fsa.txt barcodes.txt: the sequncing barcodes, corresponding to read2 from the sequencing files.
Project description:Ribosome profiling (Ribo-Seq) and RNA-Seq analysis of eEF3 depletion in yeast (Saccharomyces cerevisiae). eEF3 depletion was induced by methionine in a modified strain where the native promoter was replaced by methionine repressible MET25 promoter. Conditional depletion enables us to study global effects of an essential gene.