Differential expression and localization of Mn and Fe superoxide   dismutases in the heterocystous cyanobacterium Anabaena sp strain PCC   7120

doi:10.1128/JB.184.18.5096-5103.2002

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	Differential expression and localization of Mn and Fe superoxide dismutases in the heterocystous cyanobacterium Anabaena sp strain PCC 7120
	Li, T ; Huang, X ; Zhou, RB ; Liu, YF ; Li, B ; Nomura, C ; Zhao, JD
刊名	journal of bacteriology
	2002
关键词	MOLECULAR-CLONING THYLAKOID MEMBRANES HETR PROTEIN SP PCC-7120 SODB GENE LIFE-SPAN DAMAGE STRESS DNA TOLERANCE
DOI	10.1128/JB.184.18.5096-5103.2002
英文摘要	Superoxide dismutases (Sods) play very important roles in preventing oxidative damages in aerobic organisms. The nitrogen-fixing heterocystous cyanobacterium Anabaena sp. strain PCC 7120 has two Sod-encoding genes: a sodB, encoding a soluble iron-containing Sod (FeSod), and a soda, encoding a manganese-containing Sod (MnSod). The FeSod was purified and characterized. A recombinant FeSod was also obtained by overproduction in Escherichia coli. Immunoblot study of the FeSod during induction of heterocyst differentiation showed that the cells produced six- to eightfold more FeSod 8 h after a shift from a nitrogen-replete condition to a nitrogen-depleted condition. However, the amount of FeSod protein in filaments with mature heterocysts was the same as that in filaments grown with combined nitrogen. Superoxide anion-generating chemicals such as methyl viologen did not induce upregulation of the sodB gene expression. The predicted preprotein of the sodA gene has a leader peptide and a motif for membrane attachment at the N terminus of the mature protein. Activity staining after gel electrophoresis of the purified thylakoid membranes showed that most of the MnSod in Anabaena sp. strain PCC 7120 was located on thylakoids toward the lumenal side. Expression of the sodA gene in E. coli shows that the leader peptide was required for its activity and the membrane localization of the MnSod. Northern hybridization detected one 0.82-kb transcript of sodA. The sodA gene was upregulated by methyl viologen, whereas its amount was unchanged during heterocyst differentiation. Immunopblotting and activity staining showed that isolated heterocysts contained a lower but still significant amount of FeSod, suggesting that its function is required in heterocysts. No MnSod was observed in isolated heterocysts. These results show that the two different Sod proteins have differentiated roles in Anabaena sp. strain PCC 7120.; Microbiology; SCI(E); PubMed; 39; ARTICLE; 18; 5096-5103; 184
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/347299]
专题	生命科学学院
推荐引用方式 GB/T 7714	Li, T,Huang, X,Zhou, RB,et al. Differential expression and localization of Mn and Fe superoxide dismutases in the heterocystous cyanobacterium Anabaena sp strain PCC 7120[J]. journal of bacteriology,2002.
APA	Li, T.,Huang, X.,Zhou, RB.,Liu, YF.,Li, B.,...&Zhao, JD.(2002).Differential expression and localization of Mn and Fe superoxide dismutases in the heterocystous cyanobacterium Anabaena sp strain PCC 7120.journal of bacteriology.
MLA	Li, T,et al."Differential expression and localization of Mn and Fe superoxide dismutases in the heterocystous cyanobacterium Anabaena sp strain PCC 7120".journal of bacteriology (2002).