title: Computational prediction of the osmoregulation network in Synechococcus sp. WH8102.
abstract: BACKGROUND
  Osmotic stress is caused by sudden changes in the impermeable solute concentration around a cell, which induces instantaneous water flow in or out of the cell to balance the concentration. Very little is known about the detailed response mechanism to osmotic stress in marine Synechococcus, one of the major oxygenic phototrophic cyanobacterial genera that contribute greatly to the global CO2 fixation.
  
  
  RESULTS
  We present here a computational study of the osmoregulation network in response to hyperosmotic stress of Synechococcus sp strain WH8102 using comparative genome analyses and computational prediction. In this study, we identified the key transporters, synthetases, signal sensor proteins and transcriptional regulator proteins, and found experimentally that of these proteins, 15 genes showed significantly changed expression levels under a mild hyperosmotic stress.
  
  
  CONCLUSIONS
  From the predicted network model, we have made a number of interesting observations about WH8102. Specifically, we found that (i) the organism likely uses glycine betaine as the major osmolyte, and others such as glucosylglycerol, glucosylglycerate, trehalose, sucrose and arginine as the minor osmolytes, making it efficient and adaptable to its changing environment; and (ii) sigma38, one of the seven types of sigma factors, probably serves as a global regulator coordinating the osmoregulation network and the other relevant networks.
authors.affiliation: Department of Biochemistry and Molecular Biology and Institute of Bioinformatics, University of Georgia, Athens, GA 30602, USA.
authors.forename: Xizeng
authors.initials: X
authors.lastname: Mao
authors.forename: Victor
authors.initials: V
authors.lastname: Olman
authors.forename: Rhona
authors.initials: R
authors.lastname: Stuart
authors.forename: Ian T
authors.initials: IT
authors.lastname: Paulsen
authors.forename: Brian
authors.initials: B
authors.lastname: Palenik
authors.forename: Ying
authors.initials: Y
authors.lastname: Xu
mesh_terms: D001120:Arginine / Q000378:metabolism; D001622:Betaine / Q000378:metabolism; D011134:Polysaccharides / Q000378:metabolism*; D046940:Synechococcus / Q000737:chemistry* / Q000201:enzymology / Q000378:metabolism*; D014882:Water-Electrolyte Balance
chemical_list: D011134:Polysaccharides; D001622:Betaine; D001120:Arginine
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