Sugar sensing in the unicellular red alga Galdieria sulphuraria

• Applicant: Dr. Christine Oesterhelt
• Subject Area: Plant Physiology
• Term: from 2001 to 2007
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5327244

Recently, a new pathway for sugar sensing in yeast has been found. It is involved in the generation of a cAMP signal in response to a glucose stimulus due to activation of the adenylate cyclase by a G-protein coupled receptor system (GPCR) and sugar phosphorylation. This signalling cascade may represent a way to determine the extracellular concentration of fermentable sugars. The main object of this project is to analyse the unusual glucose phosphorylation requirement for activation of adenylate cyclase by the GPCR system. This will be done in two ways. First we will investigate the possible involvement of a protein phosphatase known to act on the cAMP pathway in yeast and on glucose phosphorylation in mammals. Second we will try to isolate mutants in which the activation of cAMP synthesis by the GPCR system is independent of glucose phosphyorylation. Because of the near universal requirement of glucose phosphorylation for glucose sensing in eukaryotic cells the results might have general applicability.

• DFG Programme: Independent Junior Research Groups