A global study has revealed the structure of a protein required for the stability and assembly of photosynthetic cells.Photosynthesis is the process by which plants, algae, and cyanobacteria convert water and carbon dioxide into oxygen. This is the foundation of all forms of life on Earth. Global warming is increasing stress levels in photosynthetic organisms. This decreases growth and poses a risk to human food supply. Krin Nickelsen, Ludwig-Maximilians-Universitaet in Munich biologist, and his research group, played a key role in a global project that has revealed the three-dimensional structure and function of a protein responsible for the formation and maintenance membranes where photosynthesis occurs. These insights will be useful in biotechnological efforts that aim to improve the plant's ability to deal with environmental stressors.The 'thylakoid membranes are where photosynthesis begins. They contain pigment-protein complexes that can absorb sunlight's energy. Since decades, it has been well known that a protein called VIPP1 is essential for the assembly and maintenance of thylakoids in all photosynthetic organisms. This stands for'vesicle inducing protein inplastids'. Steffen Heinz is a postdoctoral researcher in Nickelsen's lab and the joint first author of this new publication. "How VIPP1 actually performs that essential function has remained enigmatic until now." Researchers now have a lot more information thanks to the Helmholtz Zentrum Mnchen's new study.Photosynthesis membrane assemblyTo determine the three-dimensional structure at high resolution of VIPP1, the team used cryoelectron microscopy. This structure was analyzed in conjunction with functional investigation into the protein's mechanism of action. It revealed that VIPP1 molecules are small and form short strands which are interwoven to create a basket-like structure. This scaffold is used to assemble the thylakoid cell membrane and determines its curvature. The scientists also used a similar technique called cryo-electron imaging to photograph VIPP1 membranes in their natural form in algal cells. They introduced site-specific mutations to VIPP1, and found that their interaction with thylakoid cells is crucial for maintaining their structural integrity in light stress. This discovery shows that the protein is not only responsible for the assembly of the thylakoids but also helps them adapt to changing environmental conditions.These results will help us to better understand the mechanisms behind the formation and stability of thylakoids. These results will open up new possibilities for green plants that can withstand extreme environmental stress.
