SCyCode The Autotrophy-Heterotrophy Switch in Cyanobacteria: Coherent Decision-Making at Multiple Regulatory Layers

Cyanobacteria are the only prokaryotes performing oxygenic photosynthesis. Theyhad and have tremendous influence on the biogeochemical cycles on Earth. Recently,cyanobacteria are increasingly investigated as cell factories for a sustainableeconomy. Despite their global, environmental and rising economic importance, ourknowledge on the regulation of their primary metabolism is fragmented.Cyanobacteria switch between photoautotrophic and heterotrophic modes ofmetabolism during day/night cycles or under specific environmental conditions withthe enzymatic capacity for both life-styles being present in one cell. It is notunderstood how this remarkable metabolic plasticity, which requires coherentdecisions at multiple layers in response to different external and internal signals, isachieved. Our research network aims at answering this major unsolved question. Wewill address the function and control of key enzymes, pathways and regulators of Cmetabolismand their interplay to unveil the (hidden) regulatory layers that organizethe central metabolic routes. Therefore, the consortium, composed of experts withcomplementary skills, will use the model strain Synechocystis sp. PCC 6803 for an integrative application of advanced biochemical, transcriptomic, fluxomic, andproteomic methods.