ompH gene expression is regulated by multiple environmental cues in addition to high pressure in the deep-sea bacterium Photobacterium species strain SS9.
AUTOR(ES)
Bartlett, D H
RESUMO
Photobacterium species strain SS9 is a moderately barophilic (pressure-loving) deep-sea bacterial species which induces the expression of the ompH gene in response to elevated pressure. Here we demonstrate that at 1 atm (1 atm = 1.01325 x 10(5) Pa), ompH expression increases with cell density in 2216 marine medium batch culture and is subject to catabolite repression and the OmpH synthesis is inducible by energy (carbon) starvation. Regulatory mutants which are impaired in ompH gene expression at high pressure are also impaired in cell density regulation of ompH gene expression, indicating that the two inducing conditions overlap in their signal transduction pathways. The same promoter was activated by high cell density at 1 atm of pressure as well as during low-cell-density growth at 272 atm. Catabolite repression of ompH gene expression was induced by a variety of carbon sources, and this repression could be partially reversed in most cases by the addition of cyclic AMP (cAMP). Surprisingly, glucose repression of ompH transcription occurred only at 1 atm, not at 272 atm, despite the fact that catabolite repression was operational in SS9 under both conditions. It is suggested that ompH expression is cAMP and catabolite repressor protein dependent at 1 atm but becomes cAMP and perhaps catabolite repressor protein independent at 272 atm. Possible mechanisms of ompH gene activation are discussed.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=176696Documentos Relacionados
- Isolation and characterization of the structural gene for OmpL, a pressure-regulated porin-like protein from the deep-sea bacterium Photobacterium species strain SS9.
- Use of a reporter gene to follow high-pressure signal transduction in the deep-sea bacterium Photobacterium sp. strain SS9.
- RNA Arbitrarily Primed PCR Survey of Genes Regulated by ToxR in the Deep-Sea Bacterium Photobacterium profundum Strain SS9
- Monounsaturated but Not Polyunsaturated Fatty Acids Are Required for Growth of the Deep-Sea Bacterium Photobacterium profundum SS9 at High Pressure and Low Temperature
- FabF Is Required for Piezoregulation of cis-Vaccenic Acid Levels and Piezophilic Growth of the Deep-Sea Bacterium Photobacterium profundum Strain SS9