IsiA and Its Role in Capturing Light Energy

For decades, people have been trying to utilize solar energy, which has been seen as one of the most promising renewable energy source. On the other hand, plants, algae and cyanobacteria had already managed using solar energy as their energy source for billion years. Photosynthesis is the critical process carried out by phototrophs to capture and convert light energy to the energy currency of life, ATP and NAD(P)H, and store the energy in carbohydrates. In the very first stage, light energy is absorbed by the antenna proteins and then transferred to the photosystems where the light reactions occur. Our research focuses on one of the antenna protein, IsiA, which is a chlorophyll-binding transmembrane protein produced when cyanobacteria are grown in iron-deficient conditions. Since the concentration of bioavailable iron ions in nature is fairly low, IsiA is believed to be present and participate photosynthesis all the time and plays a significant role in capturing light energy. By probing the IsiA with novel technology, such as cross-linking followed by mass spectrometry analysis and time-resolved spectroscopy, we would like to understand how IsiA helps cyanobacteria capture light energy which can be a valuable lesson for human being to use solar energy as well.  


Chen, H.-Y.S., A. Bandyopadhyay, and H.B. Pakrasi. “Function, Regulation and Distribution of Isia, a Membrane-Bound Chlorophyll a-Antenna Protein in Cyanobacteria.” Photosynthetica (2018).

Chen, Hui-Yuan S., et al. “Reevaluating the Mechanism of Excitation Energy Regulation in Iron-Starved Cyanobacteria.” Biochimica et Biophysica Acta (BBA)-Bioenergetics (2017).