Participation of acid phospholipids in protein translocation across the bacterial cytoplasmic membrane

Abstract

Recent observations confirm the participation of acid phospholipids in protein translocation. The hypothesis proposed coupled protein translocation with transmembrane movement of acid phospholipids, their metabolism as a precursor of cell envelope components and recycling. These factors ensure the unidirectional vector value of the secretion, restoration of the membrane site competent for protein translocation and its self-organization.

Stereochemical Analysis of Interaction of Signal Peptide with Phospholipids at the Initiation of Protein Translocation Across the Membrane

“…Probably, peptide insertion into the membrane across the lipid bilayer is more likely because the lipid constituent of the membrane is more flexible and, consequently, offers more available microenvironment for peptide insertion than the membrane protein. Besides, it is confirmed by the experimental data known by now, including our own, and also by the concepts developed on their basis ( 17,18). As far as the participation of proteins in these processes is concerned, they can play an important role in protein targeting from Downloaded by [Rutgers University] at 16:53 13 April 2015 cytoplasm to the membrane surface, as well as in providing effetive interaction between SP and PL.…”

“…However, recent studies showed the existence of a close link between the secretory process and composition, turnover and physicochemical state of membrane phospholipids (16)(17)(18), and a number of hypotheses of molecular mechanism of involvement of these compounds in the secretory process were proposed (16)(17)(18)(19). The fact that, besides the signal peptide, relatively small molecules of phospholipids play an important role in the process of translocation, opened a principal possibility for the elucidation of the molecular mechanism of translocation by the theoretical methods of structural analysis.…”

“…Signal peptides of alkaline phosphatase and other proteins were studied, for the secretion of which an important role of phospholipids was established (14,18,20). Phospholipids of E. coli membranes were also studied.…”

The fructosyltransferase of Streptococcus salivarius

“…Speculation still exists, however, as to whether this translocator forms a proteinaceous 'pore' through which unfolded polypeptides are sequestered across the membrane as there is considerable evidence supporting a direct role for membrane lipids in protein translocation (Nesmeyonova & Bogdanov, 1989;de Vrije, et al, 1990;Tai, 1990). Unlike E. coli, little is known about the secretion process in Gram-positive bacteria, though recent studies with B. subtilis have led to the isolation of secY/prlA and secA homologues (Suh et al, 1990;Sadaie et al, 1991).…”

The change in membrane phospholipid composition influences protein secretion and cell envelope biogenesis in Escherichia coli

“…Phospholipids are a candidate for metabolites which are common for protein secretion and envelope biogenesis. As components of the cytoplasmic membrane, they not only form the barrier of permeability for many substances but also, being a microenvironment for many proteins and possessing metabolic and structural dynamicity, phospholipids are involved in many transmembrane processes [9][10][11][12][13]. In particular, anionic phospholipids (APL) provide optimal conditions for the functioning of protein components of secretory machinery and participate in secretion initiation through interaction with the signal peptide [14][15][16].…”