Changes in the Molecular Organization of Monogalactosyldiacyl-Glycerol between Resting and Functional States of Thylakoid Membranes

Abstract

Considerable progress in the knowledge of the molecular organization of thylakoid membranes (TM) has been made during the last decade. Pronounced lateral heterogeneity and transversal asymmetry have been recognized for protein complexes and, to a lesser extent, for lipids, thus leading to the widely accepted concept that transversal and lateral heterogeneities in TM are the structural counterpart of its vectorial functionality [1]. However, this concept entirely relies upon the basic assumption that the molecular organization of TM is similar under “resting” conditions (mostly used to study structural aspects) and “functioning” conditions. A few works have indeed suggested that protein rearrangments occur upon a dark-to-light transition [2]. Is it also the case for lipids? We show here that such changes effectively occur, at least for monogalactosyldiacylglycerol (MGDG).