title: Molecular chaperone accumulation as a function of stress evidences adaptation to high hydrostatic pressure in the piezophilic archaeon Thermococcus barophilus.
abstract: The accumulation of mannosyl-glycerate (MG), the salinity stress response osmolyte of Thermococcales, was investigated as a function of hydrostatic pressure in Thermococcus barophilus strain MP, a hyperthermophilic, piezophilic archaeon isolated from the Snake Pit site (MAR), which grows optimally at 40 MPa. Strain MP accumulated MG primarily in response to salinity stress, but in contrast to other Thermococcales, MG was also accumulated in response to thermal stress. MG accumulation peaked for combined stresses. The accumulation of MG was drastically increased under sub-optimal hydrostatic pressure conditions, demonstrating that low pressure is perceived as a stress in this piezophile, and that the proteome of T. barophilus is low-pressure sensitive. MG accumulation was strongly reduced under supra-optimal pressure conditions clearly demonstrating the structural adaptation of this proteome to high hydrostatic pressure. The lack of MG synthesis only slightly altered the growth characteristics of two different MG synthesis deletion mutants. No shift to other osmolytes was observed. Altogether our observations suggest that the salinity stress response in T. barophilus is not essential and may be under negative selective pressure, similarly to what has been observed for its thermal stress response.
authors.affiliation: Univ Lyon, ENS de Lyon, CNRS UMR 5276, Lyon, France.
authors.forename: Anaïs
authors.initials: A
authors.lastname: Cario
authors.affiliation: Univ Brest, CNRS, Ifremer, UMR 6197-Laboratoire de Microbiologie des Environnements Extrêmes (LM2E), Institut Universitaire Européen de la Mer (IUEM), rue Dumont d'Urville, 29 280 Plouzané, France.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Jebbar
authors.affiliation: Univ Brest, CNRS, Ifremer, UMR 6197-Laboratoire de Microbiologie des Environnements Extrêmes (LM2E), Institut Universitaire Européen de la Mer (IUEM), rue Dumont d'Urville, 29 280 Plouzané, France.
authors.forename: Axel
authors.initials: A
authors.lastname: Thiel
authors.affiliation: Univ Brest, PLATE-FORME TECHNOLOGIQUE RMN-RPE-SM, UFR Sciences et Techniques, Avenue Le Gorgeu, Brest, France.
authors.forename: Nelly
authors.initials: N
authors.lastname: Kervarec
authors.affiliation: Univ Lyon, ENS de Lyon, CNRS UMR 5276, Lyon, France.|Univ Lyon, INSA de Lyon, CNRS UMR 5240, Lyon, France.
authors.forename: Phil M
authors.initials: PM
authors.lastname: Oger
mesh_terms: D000222:Adaptation, Physiological; D019641:DNA, Archaeal / Q000235:genetics; D017353:Gene Deletion; D006874:Hydrostatic Pressure; D009682:Magnetic Resonance Spectroscopy; D018832:Molecular Chaperones / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D016366:Open Reading Frames; D011312:Pressure; D054712:Salinity; D012623:Seawater; D013696:Temperature; D019712:Thermococcus / Q000235:genetics* / Q000378:metabolism*
chemical_list: D019641:DNA, Archaeal; D018832:Molecular Chaperones