Identification of a regulatory protein required for pressure‐responsive gene expression in the deep‐sea bacterium Photobacterium species strain SS9

• Published in: Molecular microbiology Vol. 27; no. 5; pp. 977 - 985
• Main Authors: Welch, Timothy J., Bartlett, Douglas H.
• Format: Journal Article
• Language: English
• Published: Oxford BSL Blackwell Science Ltd, UK 01.03.1998
• Subjects: Amino Acid Sequence; Bacterial Proteins; Blotting, Western; Cloning, Molecular; DNA-Binding Proteins - genetics; DNA-Binding Proteins - physiology; Electrophoresis, Polyacrylamide Gel; Gene Deletion; Gene Expression Regulation, Bacterial; Hydrostatic Pressure; Marine; Molecular Sequence Data; Mutagenesis; Photobacterium; Photobacterium - genetics; Photobacterium - growth & development; Porins - genetics; Procaine - pharmacology; Regulon - genetics; Signal Transduction; Transcription Factors - genetics; Transcription Factors - physiology
• ISSN: 0950-382X; 1365-2958
• DOI: 10.1046/j.1365-2958.1998.00742.x

Here, we report the characterization of a gene necessary for hydrostatic pressure regulation of gene expression in the deep‐sea bacterium Photobacterium species strain SS9. The deduced amino acid sequence of the gene product shares extensive similarity to ToxR, a transmembrane DNA‐binding protein first discovered as a virulence determinant in the pathogenic bacterium Vibrio cholerae. Changes in hydrostatic pressure induce changes in both the abundance and the activity of the SS9 ToxR protein (or the activity of a ToxR‐regulated protein). As with other high‐pressure‐inducible phenomena observed in higher organisms, anaesthetics antagonize high‐pressure signalling mediated by ToxR. It is suggested that SS9 ToxR has evolved the ability to respond to pressure‐mediated alterations in membrane structure. V. cholerae and SS9 also share similarity in a ToxR‐regulated protein, indicating that part of the ToxR regulon is conserved in diverse members of the family Vibrionaceae. The SS9 ToxR system represents a useful model for studies of signal transduction and environmental adaptation in the largest portion of the biosphere, the deep sea.