Harald Hofbauer

Institute:Karl Franzens University Graz, Austria
Title:The molecular recognition of phosphatidic acid by Opi1 to control lipid metabolism in yeast
Location:Bestuursgebouw, Van Lier en Egginkzaal
Abstract:["A key decision in cellular physiology is the decision between membrane biogenesis and lipid storage. The regulatory pathways underlying these cellular processes must be carefully coordinated and tightly controlled. The lipid metabolite phosphatidic acid (PA) represents the branch point between glycerophospholipid production for cell proliferation and triacylglycerol synthesis for fat storage. PA molecules have a high metabolic turnover and also serve as critical signaling lipids. In the baker\u00b4s yeast Saccharomyces cerevisiae, the PA level of the ER is constantly monitored by the soluble repressor Opi1 via its polybasic PA binding domain to control the transcriptional program of glycerophospholipid biosynthesis. However, mechanistic details on the binding mode of Opi1 remain yet elusive. Using a combined in vivo, in vitro and in silico approach, we here identified and characterized a novel structural feature of Opi1 that enables acyl chain sensing of the lipid bilayer after initial electrostatic membrane recruitment. This allows Opi1 to rapidly respond on various derailments of membrane lipid homeostasis by directly adjusting the transcriptional program of glycerophospholipid biosynthesis."]
Host:Mike Renne (Membrane Biochemistry & Biophysics)