title: Nitrogen status dependent oxidative stress tolerance conferred by overexpression of MnSOD and FeSOD proteins in Anabaena sp. strain PCC7120.
abstract: The heterocystous nitrogen-fixing cyanobacterium, Anabaena sp. strain PCC7120 displayed two superoxide dismutase (SOD) activities, namely FeSOD and MnSOD. Prolonged exposure of Anabaena PCC7120 cells to methyl viologen mediated oxidative stress resulted in loss of both SOD activities and induced cell lysis. The two SOD proteins were individually overexpressed constitutively in Anabaena PCC7120, by genetic manipulation. Under nitrogen-fixing conditions, overexpression of MnSOD (sodA) enhanced oxidative stress tolerance, while FeSOD (sodB) overexpression was detrimental. Under nitrogen supplemented conditions, overexpression of either SOD protein, especially FeSOD, conferred significant tolerance against oxidative stress. The results demonstrate a nitrogen status-dependent protective role of individual superoxide dismutases in Anabaena PCC7120 during oxidative stress.
authors: Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai, India.
authors: Prashanth S
authors: PS
authors: Raghavan
authors: Hema
authors: H
authors: Rajaram
authors: Shree K
authors: SK
authors: Apte
mesh_terms: D017033:Anabaena / Q000254:growth & development / Q000378:metabolism* / Q000502:physiology; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D009584:Nitrogen / Q000378:metabolism*; D009586:Nitrogen Fixation / Q000235:genetics; D018384:Oxidative Stress / Q000235:genetics*; D013482:Superoxide Dismutase / Q000235:genetics* / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D013482:Superoxide Dismutase; D009584:Nitrogen