Redox regulation in multicellular cyanobacteria - a proteomics approach

Our research project

In order for an organism to be able to adapt to its surroundings it must employ numerous strategies to dynamically sense and translate changes in its environment, and hence to adjust the relevant processes within the cell. Redox control is one such strategy.

The objective of this research project is to investigate different aspects of redox control in cyanobacteria. We take a proteomic approach and focuses are on proteins acting as redox transmitters such as thioredoxins, and proteins, which are targets for redox such as transcriptional regulators and enzymes. Multicellular cyanobacteria of the genus Nostoc are used to investigate the difference in redox regulation in cells with O2 evolving photosynthesis and in non-photosynthetic cells specialized in fixation of atmospheric nitrogen, the heterocysts. Knowledge gained from this research will give insight in how cyanobacteria and other photosynthetic organisms adapts to changing environmental conditions and stress. With the characterized proteome of N2 fixing (with heterocysts) and non N2 fixing (without heterocysts) filamentous cyanobacteria Nostoc sp. PCC 7120 and Nostoc punctiforme ATCC 29133 we have developed robust experimental and statistical methods for our work, and we have shown the usefulness of quantitative shotgun proteomics in cyanobacterial research.

The overall aim is to control the redox balance and reactive oxygen species (ROS) concentrations on a system level and thereby increase the robustness of cyanobacteria for future large-scale cultivation. And finally answer the questions of: How does the multicellular cyanobacteria coordinate the redox regulatory activities in the different cells and exchange information in the form of redox intermediates to maintain overall redox homeostasis to combat oxidative stress? Could we increase the ability of cyanobacteria to tolerate environmental changes?