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:The transcriptional activator NDD1 was purified from wt and rad53 or mec1 mutant treated with hydroxyurea or methyl-methanesulfonate via HTB-tag , digested directly from the streptavidin beads, and then subjected to LC-MSMS analysis. Beads were alternatively digested with trypsin and chymotrypsin for better sequence coverage.
Project description:We explored transcriptional responses of the fission yeast to DNA damage. RNA-seq was used to characterize changes in expression profiles of all known lncRNAs and mRNAs in wild type cells and cells treated by four DNA damage agents: Camptothecin, Hydroxyurea, Methyl methanesulfonate and Phleomycin.
Project description:Purpose of profiling experiment was to examine effects of a mutation of a subunit of TFIIH, ssl1p, which has ubiquitin ligase activity.,The whole complex has previously been shown to have both kinase and helicase activities. We wanted to see if 1) there were,general transcriptional defects with these mutations, as there are with other mutations to kinase activity, and 2) if there,were transcriptional effects on DNA repair machinery when the mutants were treated with MMS, which is an alkylating agent.
