Abstract
Cyanobacteria must be able to respond to changes in their environmental conditions, including light and nutrient availibility. To simultaneously optimize multiple metabolisms in response to environmental changes, a high degree of regulation should be required. However, little is known about the regulation of cross-talk between metabolic processes in cyanobacteria. In Synechocystis sp. PCC 6803, we identified NblA as a regulator of different metabolisms. We found that NblA, isolated as a factor for phycobilisome degradation during nitrogen starvation, also regulates photosystem stoichiometry under high light conditions. In the nitrogen-fixing cyanobacterium Cyanothece sp. ATCC 51142, different metabolic processes are temporally regulated. Cyanothece performs photosynthesis during the light period and nitrogen fixation in the dark. We are searching for the regulator(s) of cross-talk between these metabolisms through a combination of genome sequencing and annotation, microarray analysis, high-throughput proteomics, and physiological measurements. These data will elucidate the complexity of metabolic regulation in cyanobacteria.
