University of Tennessee researchers have identified a molecular mechanism that controls how chloroplasts import proteins, a process critical to photosynthesis. The study, led by Professor Barry Bruce and Associate Professor Rajan Lamichhane, was published in the Biophysical Journal.
The team focused on the Toc34 protein, which acts as a gatekeeper for the chloroplast's outer membrane. Their work suggests this protein forms dynamic oligomers that open or close depending on ligand binding, effectively acting as a molecular lock.
Using single-molecule fluorescence and cross-linking techniques, the scientists observed how Toc34 oligomerization responds to specific molecules. This regulation appears to be essential for efficient protein transport, directly impacting photosynthetic output.
Understanding this lock-and-key mechanism could inform efforts to enhance crop yields or develop synthetic photosynthetic systems. The findings also offer a new perspective on organelle evolution and cellular energy management.
Co-authors included graduate student Sree Kavya Penneru and postdoctoral researcher Sriram Tiruvadi-Krishnan, who contributed to the experimental design and data analysis.