Author: Herr Dr. Amoneit
Last saved by: Saritas, Sevim

The P4-ATPase ALA10 Controls MGDG Synthesis
Juliette Jouhet, Morgane Michaud, César Botella, Eric Maréchal, and Maryse A. Block, Laboratoire de physiologie cellulaire et végétale, Université Grenoble Alpes, Grenoble, France

Biogenesis of the photosynthetic membranes is dependent on activities present in different membranes of the plant cell. Synthesis of monogalactosyldiacylglycerol (MGDG), a key lipid for thylakoid building and function, occurs in the chloroplast envelope and is linked to endomembrane phospholipid metabolism that, through PC, DAG and PA, feeds and activates the thylakoid essential MGDG synthase, MGD1. Transcriptomic analyses revealed that the expression of ALA10, a P4-type ATPase, is highly increased when MGDG synthases are inhibited by Galvestine-1. ALA10 shares a high sequence homology with several P4-type ATPases which were previously demonstrated as phospholipid translocases. Our aim was here to analyze if ALA10 contributes to lipid transfer necessary for galactolipid synthesis in Arabidopsis leaves. Our work shows that ALA10 modulates desaturation of phosphatidylcholine (PC) in endomembranes and increases chloroplast PC content and MGDG production.