How Are Plastoglobules Formed in Green Algae?

Plastoglobules are droplet-like organelles with a hydrophobic core of neutral lipids surrounded by a lipid monolayer, usually found in the chloroplasts of most plants and green algae. They not only serve as lipid storage units in the thylakoid membranes but are also involved in many cellular processes, including photoprotection, metabolite synthesis, protein recruitment, and chloroplast differentiation. Unlike lipid droplets, which nucleate, grow, and subsequently detach from the endoplasmic reticulum (ER) membrane, plastoglobules remain permanently coupled to the stromal side of the thylakoid membrane. In this study, we employ molecular dynamics simulations to investigate the growth mechanism of plastoglobules in a model thylakoid membrane of Dunaliella algae. Our findings suggest that significant membrane remodeling, likely driven by the thylakoid membrane proteins, is essential for the directional growth and stability of the plastoglobules.