Balanced regulation of expression of the gene for cytochrome cM and that of genes for plastocyanin and cytochrome c6 in Synechocystis

Malakhov, Michael P.; Malakhova, Oksana A.; Murata, Norio

doi:10.1016/s0014-5793(99)00074-5

Cited by 43 publications

(28 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Then, sll0359 was further subcloned into the self-replicating plasmid pAWG1.1 (kindly provided by Matthias Rögner, Ruhr Universität, Bochum, Germany), which is a derivative of RSF1010 (12,18), resulting in the vector pFMoe01. In this construct, the sll0359 gene was cloned downstream of the petE promoter region, which is inducible by copper (12,18,25). The obtained construct was subsequently sequenced to confirm that no mutations had been introduced.…”

Section: Methodsmentioning

confidence: 99%

An AbrB-Like Protein Regulates the Expression of the Bidirectional Hydrogenase in Synechocystis sp. Strain PCC 6803

Oliveira

Lindblad

2008

J Bacteriol

View full text Add to dashboard Cite

In the unicellular cyanobacterium Synechocystis sp. strain PCC 6803, the pentameric bidirectional Ni-Fe hydrogenase (HoxEFUYH) is the sole enzyme involved in hydrogen metabolism. Recent investigations implicated the transcription factor LexA in the regulation of the hox genes in this cyanobacterium, suggesting the factor to work as an activator. In this work, we show evidence that LexA cannot account exclusively for the regulation of the hox genes in this cyanobacterium. Therefore, we investigated which additional transcription factors interact in and may regulate the expression of the hox genes in Synechocystis sp. strain PCC 6803. By using DNA affinity assays, a transcription factor with similarity to the transition state regulator AbrB from Bacillus subtilis was isolated. Electrophoretic mobility shift assays showed that the AbrB-like protein specifically interacts with the promoter region of the hox genes as well as with its own promoter region. In addition, results obtained with two genetically modified strains of Synechocystis sp. strain PCC 6803, one with a not fully segregated inactivation mutation of the abrB-like gene and the other overexpressing the same abrB-like gene, suggest that this transcription factor functions as a regulator of hox gene expression.Two different Ni-Fe hydrogenases have been characterized physiologically, biochemically, and on the molecular level in cyanobacteria: one is named uptake hydrogenase and catalyzes the consumption of H 2 produced by the nitrogenase during N 2 fixation, and the other is termed bidirectional hydrogenase and its function is still under debate (32,37,38).Over the years, it has continuously been shown by reverse transcription-PCR and Northern blot analysis (2,3,4,15,23,27,33,38) that the transcription of cyanobacterial hydrogenases varies under different environmental conditions. Nevertheless, an understanding of which key regulators are involved is just emerging and the inherent signal transduction pathways certainly deserve better attention. Therefore, it is imperative to study the mechanisms controlling the expression of both cyanobacterial hydrogenases more closely in order to acquire an improved comprehension of their functions and also to develop novel tools for enhancing a sustainable and reliable production of H 2 from cyanobacteria (38).Recently, the first reports on the transcription factors involved in the regulation of cyanobacterial hydrogenases became available. NtcA, the nitrogen control regulator in cyanobacteria, has been suggested to mediate the transcription of the uptake hydrogenase in different cyanobacterial strains, Nostoc punctiforme PCC 73102 (24), Gloeothece sp. strain ATCC 27152 (27), and Lyngbya majuscula CCAP 1446/4 (23), as well as that of the hydrogenase maturation proteins in Lyngbya majuscula CCAP 1446/4 (15). A LexA-related protein, which has been proposed to not be involved in the classical regulation of DNA repair genes (11), was shown to interact in two different regions of the promoter of the hox genes in Synechocystis...

show abstract

Section: Methodsmentioning

confidence: 99%

An AbrB-Like Protein Regulates the Expression of the Bidirectional Hydrogenase in Synechocystis sp. Strain PCC 6803

Oliveira

Lindblad

2008

J Bacteriol

View full text Add to dashboard Cite

show abstract

“…4 for a recent review). In those species that are able to synthesize either Cyt or Pc, the expression level of the corresponding genes is controlled by the copper concentration in the growth medium (5,6).…”

mentioning

confidence: 99%

The Efficient Functioning of Photosynthesis and Respiration in Synechocystis sp. PCC 6803 Strictly Requires the Presence of either Cytochrome c6 or Plastocyanin

Durán

Hervás

Rosa

et al. 2004

Journal of Biological Chemistry

View full text Add to dashboard Cite

In cyanobacteria, cytochrome c 6 and plastocyanin are able to replace each other as redox carriers in the photosynthetic and respiratory electron transport chains with the synthesis of one or another protein being regulated by the copper concentration in the culture medium. However, the presence of a third unidentified electron carrier has been suggested. To address this point, we have constructed two deletion mutants of the cyanobacterium Synechocystis sp. PCC 6803, each variant lacking either the petE or petJ gene, which respectively codes for the copper or heme protein. The photoautotrophic and heterotrophic growth rate of the two mutants in copper-free and copper-supplemented medium as well as their photosystem I reduction kinetics in vivo were compared with those of wild-type cells. The two mutant strains grow at equivalent rates and show similar in vivo photosystem I reduction kinetics as wildtype cells when cultured in media that allow the expression of just one of the two electron donor proteins, but their ability to grow and reduce photosystem I is much lower when neither cytochrome c 6 nor plastocyanin is expressed. These findings indicate that the normal functioning of the cyanobacterial photosynthetic and respiratory chains obligatorily depends on the presence of either cytochrome c 6 or plastocyanin.

show abstract

“…By contrast, the expression of genes for cytochrome c 6 and plastocyanin is suppressed under such stress conditions. These observations suggest that plastocyanin and/or cytochrome c 6 , which dominate under nonstressed conditions, might be replaced by cytochrome c M under stress conditions (7 ).…”

Section: Introductionmentioning

confidence: 85%

“…However, both photosynthesis and respiration in mutant cells with a disrupted gene for cytochrome c M (1cytM cells) proceed as ef ciently as they do in wild-type cells (1). We found recently that the level of expression of the cytM gene is extremely low under normal growth conditions (34 ± C, white light at 70 ¹E m ¡2 s ¡1 ), but the level rises when cells are exposed to stress conditions, such as low temperature (22 ± C) or high-intensity light (2000 ¹E m ¡2 s ¡1 ) (7 ). By contrast, the expression of genes for cytochrome c 6 and plastocyanin is suppressed under such stress conditions.…”

Section: Introductionmentioning

confidence: 99%

Optical Study of Cytochrome cM Formation in Synechocystis

Шувалов

Allakhverdiev²,

Sakamoto³

et al. 2001

IUBMB Life

View full text Add to dashboard Cite

show abstract

Balanced regulation of expression of the gene for cytochrome c_M and that of genes for plastocyanin and cytochrome c₆ in Synechocystis

Cited by 43 publications

References 26 publications

An AbrB-Like Protein Regulates the Expression of the Bidirectional Hydrogenase in Synechocystis sp. Strain PCC 6803

An AbrB-Like Protein Regulates the Expression of the Bidirectional Hydrogenase in Synechocystis sp. Strain PCC 6803

The Efficient Functioning of Photosynthesis and Respiration in Synechocystis sp. PCC 6803 Strictly Requires the Presence of either Cytochrome c6 or Plastocyanin

Optical Study of Cytochrome cM Formation in Synechocystis

Contact Info

Product

Resources

About