PMID:10207920
| Citation |
Padan, E, Gerchman, Y, Rimon, A, Rothman, A, Dover, N and Carmel-Harel, O (1999) The molecular mechanism of regulation of the NhaA Na+/H+ antiporter of Escherichia coli, a key transporter in the adaptation to Na+ and H+. Novartis Found. Symp. 221:183-96; discussion 196-9 |
|---|---|
| Abstract |
The NhaA Na+/H+ antiporter is the main system responsible for adaptation to Na+ and alkaline pH (in the presence of Na+) in Escherichia coli and many other enteric bacteria. It is under intricate control. At the protein level it is regulated directly by pH, one of its regulatory signals. A pH shift from 7 to 8.5 activates the antiporter and, in a fashion correlated with the activity change, confers a conformation change that, in isolated membrane vesicles, is reflected in the exposure of trypsin-cleavable sites. H225 and G338 are essential for the pH response of NhaA. nhaA transcription is dependent on NhaR, a positive regulator of the LysR family, and is regulated by Na+, the other environmental signal. Na+ affects the NhaR/nhaA interaction directly by changing the footprint of NhaR on nhaA in a pH-dependent fashion. The expression of nhaA is also under global regulation of H-NS. We suggest that the pattern of regulation of nhaA found in E. coli is a paradigm for the response of proteins and genes to H+ and Na+, the most common ions that challenge every cell. |
| Links | |
| Keywords |
Adaptation, Physiological/physiology; Amino Acid Sequence; Bacterial Proteins/metabolism; DNA, Bacterial/metabolism; DNA-Binding Proteins; Escherichia coli/metabolism; Escherichia coli/physiology; Escherichia coli Proteins; Membrane Proteins/metabolism; Molecular Sequence Data; Protons; Sodium; Sodium-Hydrogen Antiporter/metabolism; Transcription Factors/metabolism |
| edit table |
Significance
You can help EcoliWiki by summarizing why this paper is useful
Useful Materials and Methods
You can help Ecoliwiki by describing the useful materials (strains, plasmids, antibodies, etc) described in this paper.
Annotations
<annotationlinks/>
EcoliWiki Links
Add links to pages that link here (e.g. gene, product, method pages)
References
See Help:References for how to manage references in EcoliWiki.