[Possible participation of acid phospholipids in the translocation of secreted proteins through the cytoplasmic membrane of bacteria].

The work presents a brief review of data on the interrelation between the biosynthesis and secretion of proteins in bacteria, and between metabolism, composition and physicochemical state of membrane lipids. Based on the analysis of these data in view of the modern ideas of the dynamic character of the membrane lipid structure, a hypothesis concerning the active participation of acid phospholipids in the translocation of protein and phospholipids through the bacterial cytoplasmic membrane is advanced. A new model of the coupled translocation of protein and phospholipids through the membrane is proposed which differs from the previous ones because it accounts not only the role of the secreted protein structure in its translocation through the membrane but assumes an active participation of membranes themselves (specifically phospholipids) in this process. The model assumes the interaction between a signal peptide of the de novo synthesized protein and acid phospholipids of membranes. Such an interaction initiates a transmembrane movement of phospholipids and a coupled translocation of phospholipids and protein, in which phospholipids and proteins secreted favor the movement of each other.