Poster abstracts
Poster number 102 submitted by Elizabeth Raupach
Analysis of ncDNA transcription for roles in regulating gene expression
Elizabeth Raupach (Department of Biological Sciences, University of Pittsburgh), Joseph Martens (Department of Biological Sciences, University of Pittsburgh)
Abstract:
Transcription of non-coding DNA (ncDNA) is widespread in eukaryotes and plays important regulatory roles. Previous studies have elucidated one such regulatory mechanism at the S. cerevisiae gene SER3. The act of transcribing SRG1, a non-coding RNA (ncRNA), across the SER3 promoter positions nucleosomes over the SER3 upstream activating sequences, which serve as a physical barrier to prevent transcription of SER3. The pervasiveness of non-coding transcription suggests that this and other regulatory mechanisms mediated by non-coding transcription may exist throughout the genome. To explore this possibility, I selected six candidate yeast genes expressing unstable ncRNAs over their promoters and analyzed the effects of disrupting intergenic transcription on open reading frame transcript expression. Through this unbiased approach, we identified a previously unknown mechanism of transcription regulation at the ECM3 gene. In contrast to the mechanism of SER3 regulation, intergenic transcription seems to activate ECM3 expression. Further analysis has identified roles for the Paf1 complex in ECM3 activation through the methylation of histone H3K4. Additionally, a longer intergenic transcript is present in the absence of Paf1. Although this transcript awaits further characterization, it may arise from a termination defect and could potentially provide a spatial and/or temporal dimension to ECM3 regulation. Thus, ECM3 is an interesting model gene for elucidation of a novel regulatory mechanism mediated by non-coding transcription.
Keywords: ncRNA, transription, chromatin