Dynamic ubiquitination determines transcriptional coactivator activity
Tuesday 25 September 2018, 1.00PM
Speaker(s): Dr Steven Spoel, Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh
Gene expression plays pivotal roles in the development of eukaryotic cells and their response to the environment. Failure to precisely program cellular gene expression often has pathological or deleterious consequences. In plants, hormone-responsive transcriptional programs are controlled by nuclear E3 ubiquitin ligases that function as both hormone receptors and as transcription cofactors. The plant immune hormone salicylic acid is perceived by a nuclear E3 ubiquitin ligase that targets the indispensable transcriptional coactivator NPR1 for proteasome-mediated degradation. Paradoxically, turnover of NPR1 coactivator is necessary for the activation of its target genes, suggesting that transcription may require continuous delivery of fresh NPR1 coactivator to gene promoters. I will discuss evidence that this unusual mode of gene regulation involves various ubiquitin-modifying enzymes that establish a processive yet dynamic transcriptional timer for NPR1 activity and enable proteasomes to function as transcriptional amplifiers.
Further details of Dr Spoel's research are available on his website : http://spoel.bio.ed.ac.uk/