Objective Nutritional gene regulation is of outstanding interest as a sedentary lifestyle and high calorie diet in western society increases the prevalence of metabolic disorders, e.g. diabetes and obesity. I have shown that a stress signalling pathway from the endo plasmic reticulum (ER) to the nucleus, the unfolded protein response (UPR), transduces a nitrogen signal. The read-out of the UPR, the basic leucine zipper (bZIP) transcription factor Hac1p, repressed transcription of genes activated by nitrogen-starvation.This repression required the catalytic activity of the RPD3-SIN3 histone deacetylase (HDAC). Hac1p also activates transcription of ER chaperone genes when protein folding in the ER is inhibited. Activation by Hac1p requires the Gcn5p histone acetyltransf erase (HAT). Gcn5p activates transcription by acetylating lysine residues in core histones. Through deacetylation of an overlapping set of lysine residues Rpd3p represses transcription. This strongly suggests that interaction of Hac1p with Gcn5p and Rpd3p is tightly regulated to avoid simultaneous activation of directly opposing transcriptional regulators. To understand the mechanism that controls Hac1p function in response to environmental stimuli I propose to generate Hac1p mutants that are selectively defective in activation or repression only. Site-directed mutagenesis will be used to alter well-known features of this bZIP transcription factor. Random mutagenesis will identify additional mutants. Mutants will be scored in agar plate reporter assays and verified by Northern blotting.Interaction of these mutants with the HDAC and HAT will be characterised using immuno-precipitation techniques. If separable, this work will identify regulatory mutants of Hac1p, which will enable database searches or genetic suppressor screens for genes that are controlling Hac1p function. This work will elucidate important aspects of how a eukaryotic cell regulates signalling specificity of an inter-organellar signalling pathway. Fields of science natural sciencescomputer and information sciencesdatabasesnatural sciencesbiological sciencesgeneticsDNAmedical and health sciencesclinical medicineendocrinologydiabetesnatural sciencesbiological sciencesbiochemistrybiomoleculesproteinsprotein foldingmedical and health scienceshealth sciencesnutritionobesity Programme(s) FP6-MOBILITY - Human resources and Mobility in the specific programme for research, technological development and demonstration "Structuring the European Research Area" under the Sixth Framework Programme 2002-2006 Topic(s) MOBILITY-4.2 - Marie Curie International Reintegration Grants (IRG) Call for proposal FP6-2002-MOBILITY-12 See other projects for this call Funding Scheme IRG - Marie Curie actions-International re-integration grants Coordinator UNIVERSITY OF DURHAM EU contribution No data Address Old Elvet DURHAM United Kingdom See on map Links Website Opens in new window Total cost No data