FIGURE 2.

Schematic diagram of vesicle formation and movement in chloroplasts. Proteins included are those with suggested involvement in chloroplast vesicle transport, and verified to be chloroplast localized. VIPP1 (pink), FZL (green), and THF1 (yellow) are located both at the donor membrane (inner envelope) and the acceptor membrane (thylakoids), and could thus participate in both fission and fusion of vesicles. CPSAR1 (violet) is located at the donor membrane, the vesicle and in the stroma, indicating that it plays a similar role as the cytosolic Sar1, i.e., in an active GTP-bound state it helps to form vesicles, and in an inactive GDP-bound state it is recycled back to the donor membrane for a subsequent cycle. THF1 (yellow) and CPRabA5e (blue) are both located in the stroma and the acceptor membrane (thylakoids) may interact with the vesicle just prior to fusion and facilitating this step. SCO2/CYO1 (turquoise) and CURT1 (black) are located at the acceptor membrane and may interact with vesicles for the transport of molecules, e.g., cargo protein(s; red) and facilitating the fusion (delivery) step.