title: Molecular adaptation and salt stress response of Halobacterium salinarum cells revealed by neutron spectroscopy.
abstract: Halobacterium salinarum is an extreme halophile archaeon with an absolute requirement for a multimolar salt environment. It accumulates molar concentrations of KCl in the cytosol to counterbalance the external osmotic pressure imposed by the molar NaCl. As a consequence, cytosolic proteins are permanently exposed to low water activity and highly ionic conditions. In non-adapted systems, such conditions would promote protein aggregation, precipitation, and denaturation. In contrast, in vitro studies showed that proteins from extreme halophilic cells are themselves obligate halophiles. In this paper, adaptation via dynamics to low-salt stress in H. salinarum cells was measured by neutron scattering experiments coupled with microbiological characterization. The molecular dynamic properties of a proteome represent a good indicator for environmental adaptation and the neutron/microbiology approach has been shown to be well tailored to characterize these modifications. In their natural setting, halophilic organisms often have to face important variations in environmental salt concentration. The results showed deleterious effects already occur in the H. salinarum proteome, even when the external salt concentration is still relatively high, suggesting the onset of survival mechanisms quite early when the environmental salt concentration decreases.
authors.affiliation: Institut de Biologie Structurale (IBS), University Grenoble Alpes, 38027, Grenoble, France.|CNRS, IBS, 38027, Grenoble, France.|CEA, DSV, IBS, 38027, Grenoble, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Vauclare
authors.affiliation: Institut de Biologie Structurale (IBS), University Grenoble Alpes, 38027, Grenoble, France.|CNRS, IBS, 38027, Grenoble, France.|CEA, DSV, IBS, 38027, Grenoble, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Marty
authors.affiliation: Institut de Biologie Structurale (IBS), University Grenoble Alpes, 38027, Grenoble, France.|CNRS, IBS, 38027, Grenoble, France.|CEA, DSV, IBS, 38027, Grenoble, France.|Institut Laue Langevin, B.P. 156X, 38042, Grenoble Cedex 9, France.
authors.forename: Elisa
authors.initials: E
authors.lastname: Fabiani
authors.affiliation: Institut de Biologie Structurale (IBS), University Grenoble Alpes, 38027, Grenoble, France.|CNRS, IBS, 38027, Grenoble, France.|CEA, DSV, IBS, 38027, Grenoble, France.|Institut Laue Langevin, B.P. 156X, 38042, Grenoble Cedex 9, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Martinez
authors.affiliation: Institut Laue Langevin, B.P. 156X, 38042, Grenoble Cedex 9, France.
authors.forename: Marion
authors.initials: M
authors.lastname: Jasnin
authors.affiliation: Institut de Biologie Structurale (IBS), University Grenoble Alpes, 38027, Grenoble, France.|CNRS, IBS, 38027, Grenoble, France.|CEA, DSV, IBS, 38027, Grenoble, France.
authors.forename: Frank
authors.initials: F
authors.lastname: Gabel
authors.affiliation: Institut de Biologie Structurale (IBS), University Grenoble Alpes, 38027, Grenoble, France.|Institut Laue Langevin, B.P. 156X, 38042, Grenoble Cedex 9, France.
authors.forename: Judith
authors.initials: J
authors.lastname: Peters
authors.affiliation: Institut de Biologie Structurale (IBS), University Grenoble Alpes, 38027, Grenoble, France.|Institut Laue Langevin, B.P. 156X, 38042, Grenoble Cedex 9, France.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Zaccai
authors.affiliation: Institut de Biologie Structurale (IBS), University Grenoble Alpes, 38027, Grenoble, France. franzetti@ibs.fr.|CNRS, IBS, 38027, Grenoble, France. franzetti@ibs.fr.|CEA, DSV, IBS, 38027, Grenoble, France. franzetti@ibs.fr.|Institut de Biologie Structurale, 71 avenue des Martyrs, CS 10090, 38044, Grenoble Cedex 9, France. franzetti@ibs.fr.
authors.forename: Bruno
authors.initials: B
authors.lastname: Franzetti
mesh_terms: D019843:Archaeal Proteins / Q000235:genetics / Q000378:metabolism; D019617:Halobacterium salinarum / Q000235:genetics* / Q000378:metabolism; D011188:Potassium / Q000378:metabolism; D020543:Proteome / Q000235:genetics / Q000378:metabolism*; D055049:Salt Tolerance; D013312:Stress, Physiological
chemical_list: D019843:Archaeal Proteins; D020543:Proteome; D011188:Potassium
keywords: Enzyme structure; Function; Function of extremophiles; Halophiles; Macromolecular structure; Protein stability