TY  - JOUR
A1  - Vorburger, Thomas
A1  - Nedielkov, Ruslan
A1  - Brosig, Alexander
A1  - Bok, Eva
A1  - Schunke, Emina
A1  - Steffen, Wojtek
A1  - Mayer, Sonja
A1  - Goetz, Friedrich
A1  - Möller, Heiko Michael
A1  - Steuber, Julia
T1  - Role of the Na+-translocating NADH:quinone oxidoreductase in voltage generation and Na+ extrusion in Vibrio cholerae
JF  - Biochimica et biophysica acta : Bioenergetics
N2  - For Vibrio cholerae, the coordinated import and export of Na+ is crucial for adaptation to habitats with different osmolarities. We investigated the Na+-extruding branch of the sodium cycle in this human pathogen by in vivo Na-23-NMR spectroscopy. The Na+ extrusion activity of cells was monitored after adding glucose which stimulated respiration via the Na+-translocating NADH:quinone oxidoreductase (Na+-NQR). In a V. cholerae deletion mutant devoid of the Na+-NQR encoding genes (nqrA-F), rates of respiratory Na+ extrusion were decreased by a factor of four, but the cytoplasmic Na+ concentration was essentially unchanged. Furthermore, the mutant was impaired in formation of transmembrane voltage (Delta psi, inside negative) and did not grow under hypoosmotic conditions at pH 8.2 or above. This growth defect could be complemented by transformation with the plasmid encoded nqr operon. In an alkaline environment, Na+/H+ antiporters acidify the cytoplasm at the expense of the transmembrane voltage. It is proposed that, at alkaline pH and limiting Na+ concentrations, the Na+-NQR is crucial for generation of a transmembrane voltage to drive the import of H+ by electrogenic Na+/H+ antiporters. Our study provides the basis to understand the role of the Na+-NQR in pathogenicity of V. cholerae and other pathogens relying on this primary Na+ pump for respiration. (C) 2015 Elsevier B.V. All rights reserved.
KW  - Nuclear magnetic resonance (NMR)
KW  - Sodium transport
KW  - Vibrio cholerae
KW  - Respiration
KW  - Na+ homeostasis
KW  - Hypoosmotic stress
Y1  - 2016
U6  - https://doi.org/10.1016/j.bbabio.2015.12.010
SN  - 0005-2728
SN  - 0006-3002
VL  - 1857
SP  - 473
EP  - 482
PB  - Elsevier
CY  - Amsterdam
ER  -