Salt Stress Induced Changes in the Exoproteome of the Halotolerant Bacterium Tistlia consotensis Deciphered by Proteogenomics.
The ability of bacteria to adapt to external osmotic changes is fundamental for their survival. Halotolerant microorganisms, such as Tistlia consotensis, have to cope with continuous fluctuations in the salinity of their natural environments which require effective adaptation strategies against salt stress. Changes of extracellular protein profiles from Tistlia consotensis in conditions of low and high salinities were monitored by proteogenomics using a bacterial draft genome. At low salinity, we detected greater amounts of the HpnM protein which is involved in the biosynthesis of hopanoids. This may represent a novel, and previously unreported, strategy by halotolerant microorganisms to prevent the entry of water into the cell under conditions of low salinity. At high salinity, proteins associated with osmosensing, exclusion of Na+ and transport of compatible solutes, such as glycine betaine or proline are abundant. We also found that, probably in response to the high salt concentration, T. consotensis activated the synthesis of flagella and triggered a chemotactic response neither of which were observed at the salt concentration which is optimal for growth. Our study demonstrates that the exoproteome is an appropriate indicator of adaptive response of T. consotensis to changes in salinity because it allowed the identification of key proteins within its osmoadaptive mechanism that had not previously been detected in its cell proteome.
Unidad de Saneamiento y Biotecnología Ambiental-Departamento de Biología-Pontificia Universidad Javeriana, POB 56710, Bogotá, D.C., Colombia; Colombian Center for Genomics and Bioinformatics of Extreme Environments-GeBiX, Bogotá, D.C., Colombia.
Carolina
C
Rubiano-Labrador
CEA, DSV, iBEB, SBTN, Lab Biochim System Perturb, Bagnols-sur-Cèze, F-30207, France.
Céline
C
Bland
CEA, DSV, iBEB, SBTN, Lab Biochim System Perturb, Bagnols-sur-Cèze, F-30207, France.
Guylaine
G
Miotello
CEA, DSV, iBEB, SBTN, Lab Biochim System Perturb, Bagnols-sur-Cèze, F-30207, France.
Jean
J
Armengaud
Unidad de Saneamiento y Biotecnología Ambiental-Departamento de Biología-Pontificia Universidad Javeriana, POB 56710, Bogotá, D.C., Colombia; Colombian Center for Genomics and Bioinformatics of Extreme Environments-GeBiX, Bogotá, D.C., Colombia.
Sandra
S
Baena
D000222:Adaptation, Physiological / Q000235:genetics / Q000502:physiology*; D000595:Amino Acid Sequence; D001483:Base Sequence; D001692:Biological Transport / Q000235:genetics; D005407:Flagella / Q000378:metabolism; D016680:Genome, Bacterial / Q000235:genetics; D008969:Molecular Sequence Data; D009997:Osmotic Pressure / Q000502:physiology*; D021382:Protein Sorting Signals / Q000235:genetics; D020543:Proteome / Q000235:genetics; D012244:Rhodospirillaceae / Q000235:genetics / Q000502:physiology*; D054712:Salinity; D055049:Salt Tolerance / Q000235:genetics / Q000502:physiology*; D017422:Sequence Analysis, DNA; D012965:Sodium Chloride / Q000378:metabolism*
D021382:Protein Sorting Signals; D020543:Proteome; D012965:Sodium Chloride