Nucleotide and negatively charged lipid‐dependent vesicle aggregation caused by SecA
Authors:
- 27 September 1993
- journal article
- Published by Wiley in FEBS Letters
- Vol. 331 (1-2) , 19-24
Abstract
SecA which is an overall acidic protein was found to induce an increase in the turbidity of a solution of vesicles consisting of negatively charged phospholipids. This increase was found to be due to an aggregation of the vesicles mediated by SecA. The SecA‐mediated vesicle aggregation was not found for zwitterionic 1,2‐dioleoyl‐sn‐glycero‐3‐phosphocholine and showed a large dependence on both temperature and ionic strength. Furthermore it was shown that ATP and to a lesser extent ADP+Pi were able to reduce the SecA‐mediated vesicle aggregation, while no effect could be seen for a non‐hydrolysable ATP analog AMP‐PNP. Using the steady state fluorescence anisotropy of 1,6‐diphenyl‐1,3,5‐hexatriene present in 1,2‐dioleoyl‐sn‐glycero‐3‐phosphoglycerol vesicles we could show that SecA inserts in the bilayer. Monolayer studies confirmed that SecA is able to cause close contact between two membranes and gave a direct insight into the different types of lipid‐protein interactions involved. From our results we propose that the SecA monomer possesses two lipid‐binding sites which in the functional dimer conformation are responsible for the SecA‐mediated vesicle aggregation.Keywords
This publication has 22 references indexed in Scilit:
- Elevated cytosolic concentrations of SecA compensate for a protein translocation defect in Escherichia coli cells with reduced levels of negatively charged phospholipidsFEBS Letters, 1992
- SecA insertion into phospholipids is stimulated by negatively charged lipids and inhibited by ATP: a monolayer studyBiochemistry, 1992
- Hydrophobic content and lipid interactions of wild-type and mutant OmpA signal peptides correlate with their in vivo functionBiochemistry, 1991
- Quantitative renaturation from a guanidine-denatured state of the SecA dimer, a 200 KDa protein involved in protein secretion in EscherichiacoliBiochemical and Biophysical Research Communications, 1990
- The binding cascade of SecB to SecA to SecYE mediates preprotein targeting to the E. coli plasma membraneCell, 1990
- Gramicidin A induced fusion of large unilamellar dioleoylphosphatidylcholine vesicles and its relation to the induction of type II nonbilayer structuresBiochemistry, 1990
- Tryptophan fluorescence study on the interaction of the signal peptide of the Escherichia coli outer membrane protein PhoE with model membranesBiochemistry, 1990
- Protection by sugars against phase transition-induced leak in hydrated dimyristoylphosphatidylcholine liposomesBiochimica et Biophysica Acta (BBA) - Biomembranes, 1990
- The ATPase activity of secA is regulated by acidic phospholipids, secY, and the leader and mature domains of precursor proteinsCell, 1990
- Analysis of membrane and surface protein sequences with the hydrophobic moment plotJournal of Molecular Biology, 1984