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Open Journal of Biology and Biochemistry

ISSN: 2227-7021
Volume 2, 2017


Open Journal of Biology and Biochemistry, 2012, 1-1 [Research Article]

Prominent role of the three Synechocystis PchR-like regulators in the defense against metal and oxidative stresses

Badrish Soni1, Laetitia Houot1, Corinne Cassier-Chauvat1,2, Franck Chauvat1,*
1 CEA, iBiTec-S, SBIGeM, LBI, Bat 142 CEA-Saclay, F-91191 Gif sur Yvette CEDEX, France
2 CNRS, URA 2096, F-91191 Gif sur Yvette CEDEX, France

Corresponding Author & Address:

Franck Chauvat
CEA, iBiTec-S, SBIGeM, LBI, Bat 142 CEA-Saclay, F-91191 Gif sur Yvette CEDEX, France; Email: franck.chauvat@cea.fr; Tel: (33) 1 69 08 78 11; Fax: (33) 1 69 08 80 46

Article History:
Published: 4th January, 2012   Accepted: 4th January, 2012
Received: 28th October, 2011   Revised:  9th December, 2011

© Chauvat et al.; licensee Ross Science Publishers

ROSS Open Access articles will be distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided that the original work will always be cited properly.

Keywords: cyanobacterium, iron regulation, metal stress, oxidative stress, transcription factor

Abstract:

The interplay between iron homeostasis and the defense to metal and oxidative stresses is crucial to the life of cyanobacteria, which perform the iron-requiring oxidative stress-generating photosynthetic process that supports a large part of the biosphere. Thus, we have investigated the role of the three PchR-like regulators of the model cyanobacterium Synechocystis PCC6803, which we previously found to be regulated by iron, cadmium and H2O2 stresses. Consistently, we presently report that the three PchR regulators are pleiotropic in operating in the tolerance to metals (Fe, Cd and Co) and oxidative (hydrogen peroxide, menadione and methylene blue) stresses. We also studied in detail the promoter of the pchR3 gene through transcriptional fusion to the cat reporter gene of our replicative promoter probe vector. We show that the pchR3 promoter is complex in comprising in that order (i) a positive element (PE); (ii) a negative element (NEu) upstream of (iii) the basic promoter (BP) which harbors a canonical –10 promoter box but no –35 box; and (iv) a negative element (NEd) downstream of BP. Interestingly, we found that the PE and NEu elements and part of BP are all located in the coding sequence of the gene (sll1488) upstream of pchR3, while the NEd element occurs in the pchR3 untranslated leader region, emphasizing that such regions can influence gene expression in cyanobacteria.



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