Anionic phospholipid gradients: an uncharacterized frontier of the plant endomembrane network
Résumé
Anionic phospholipids include phosphatidic acid (PA), phosphatidylserine (PS), phosphatidylinositol (PI), and its phosphorylated derivatives the phosphoinositides (e.g. phosphatidylinositol-4-phosphate (PI4P) or phosphatidylinositol-4,5-bisphosphate (PI(4,5)P2)). Although they are low abundant lipids, they are particularly important for membrane functions. In particular, anionic lipids act as biochemical and biophysical landmarks that contribute to the establishment of membrane identity, signaling activities, and compartment morphodynamics. Each anionic lipid accumulates in different endomembranes according to a unique subcellular pattern, where they locally provide docking platforms for proteins. As such, they are mostly believed to act in the compartments in which they accumulate. However, mounting evidence throughout eukaryotes suggests that anionic lipids are not as compartment-specific as initially thought and that they are instead organized as concentration gradients across different organelles. In this update, we review the evidence for the existence of anionic lipid gradients in plants. We then discuss the possible implication of these gradients in lipid dynamics and homeostasis, but also in coordinating subcellular activities. Finally, we introduce the notion that anionic lipid gradients at the cellular scale may translate into gradients at the organismal level, which could have implications for plant development.
Domaines
BotaniqueOrigine | Fichiers produits par l'(les) auteur(s) |
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