title: Proteomic analysis reveals contrasting stress response to uranium in two nitrogen-fixing Anabaena strains, differentially tolerant to uranium.
abstract: Two strains of the nitrogen-fixing cyanobacterium Anabaena, native to Indian paddy fields, displayed differential sensitivity to exposure to uranyl carbonate at neutral pH. Anabaena sp. strain PCC 7120 and Anabaena sp. strain L-31 displayed 50% reduction in survival (LD50dose), following 3h exposure to 75μM and 200μM uranyl carbonate, respectively. Uranium responsive proteome alterations were visualized by 2D gel electrophoresis, followed by protein identification by MALDI-ToF mass spectrometry. The two strains displayed significant differences in levels of proteins associated with photosynthesis, carbon metabolism, and oxidative stress alleviation, commensurate with their uranium tolerance. Higher uranium tolerance of Anabaena sp. strain L-31 could be attributed to sustained photosynthesis and carbon metabolism and superior oxidative stress defense, as compared to the uranium sensitive Anabaena sp. strain PCC 7120.
  
  
  CONCLUSIONS
  Uranium responsive proteome modulations in two nitrogen-fixing strains of Anabaena, native to Indian paddy fields, revealed that rapid adaptation to better oxidative stress management, and maintenance of metabolic and energy homeostasis underlies superior uranium tolerance of Anabaena sp. strain L-31 compared to Anabaena sp. strain PCC 7120.
authors.affiliation: Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India.
authors.forename: Bandita
authors.initials: B
authors.lastname: Panda
authors.affiliation: Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India.
authors.forename: Bhakti
authors.initials: B
authors.lastname: Basu
authors.affiliation: Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India.
authors.forename: Celin
authors.initials: C
authors.lastname: Acharya
authors.affiliation: Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India.
authors.forename: Hema
authors.initials: H
authors.lastname: Rajaram
authors.affiliation: Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India. Electronic address: aptesk@barc.gov.in.
authors.forename: Shree Kumar
authors.initials: SK
authors.lastname: Apte
mesh_terms: D017033:Anabaena / Q000187:drug effects* / Q000378:metabolism; D015180:Electrophoresis, Gel, Two-Dimensional; D007928:Lethal Dose 50; D018384:Oxidative Stress / Q000187:drug effects*; D010788:Photosynthesis / Q000187:drug effects*; D020543:Proteome / Q000187:drug effects* / Q000378:metabolism; D040901:Proteomics; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014501:Uranium / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D020543:Proteome; D014874:Water Pollutants, Chemical; D014501:Uranium
keywords: Anabaena 7120; Anabaena L-31; Diazotrophic cyanobacteria; Oxidative stress; Photosynthesis; Proteomic response; Uranium exposure