Abstract
The role of the prqR gene in the regulation of the adaptive response of the cyanobacteriumSynechocystis sp. PCC6803 to the oxidative stress induced with methyl viologen (MV) was studied. For this, mRNA levels of prqR and the genes, which may be involved in the control of resistance to MV, was determined by means of Northern blot hybridization in wild-type cells and in the MV-resistant Prq20 mutant with a mutation located in the DNA-binding domain of the PrqR protein. It was revealed that the prqR gene belongs to the prqR–prqA operon and downregulates its transcription. In cells of the wild-type strain treated with MV, the autorepressor activity of the PrqR protein enhances and transcript levels of mvrA and sodB genes encoding respectively an assumed transporter protein and iron-containing superoxide dismutase increases significantly. The prqR gene may be involved in the negative, indirect control of transcription of these genes. In this connection, the Prq20 mutant is characterized by an MV-independent derepression of the prqR–prqA operon and by a slightly increased transcript levels of mvrA and sodBgenes not stimulated by MV. Moreover, the expression of mvrA and sodB genes was significantly lower than in wild-type cells after the MV treatment. On the strength of this evidence, it is assumed that the main mechanism underlying for the resistance to MV in the Prq20 mutant is derepression of the prqAgene, the product of which is homologous to multidrug transporters, the drug efflux proteins.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Farr, S.B. and Kogoma, T., Oxidative Stress Responses in Escherichia coli and Salmonella typhimurium, Microbiol. Rev., 1991, vol. 55, pp. 561-585.
Asada, K., Production and Action of Active Oxygen Species in Photosynthesis Tissues, Causes of Photooxidative Stress and Amelioration of Defense Systems in Plants, Foyer, C.H. and Mullineaux, P.M., Eds., Boca Raton: CRC, 1994, pp. 77-104.
Storz, G. and Imlay, J.A., Oxidative Stress, Curr. Opin. Microbiol., 1999, vol. 2, pp. 188-194.
Pomposiello, P. and Demple, B., Redox-Operated Genetic Switches: The SoxR and SoxS Transcription Factors, Trends Biotechnol., 2001, vol. 19, pp. 109-114.
Greenberg, J.T., Monach, P.A., Chou, J.H., et al., Positive Control of a Global Antioxidant Defense Regulon Activated by Superoxide-Generating Agents in Escherichia coli, Proc. Natl. Acad. Sci. USA, 1990, vol. 87, pp. 6181-6185.
Tsaneva, I.R. and Weiss, B., soxR, a Locus Governing a Superoxide Response Regulon in Escherichia coli K-12, J. Bacteriol., 1990, vol. 172, pp. 4197-4205.
Miyake, C., Michihata, F., and Asada, K., Scavenging of Hydrogen Peroxide in Prokaryotic and Eukaryotic Algae: Acquisition of Ascorbate Peroxidase during the Evolution of Cyanobacteria, Plant Cell Physiol., 1991, vol. 32, pp. 33-43.
Mutsuda, M., Ishikawa, T., Takeda, T., and Shigeoka, S., The Catalase-Peroxidase of Synechococcus sp. PCC 7942: Purification, Nucleotide Sequence Analysis and Expression in Escherichia coli, Biochem. J., 1996, vol. 316, pp. 251-257.
Obinger, C., Regelsberger, G., Strasser, G., et al., Purification and Characterization of a Homodimeric Catalase-Peroxidase from the Cyanobacterium Anacystis nidulans, Biochem. Biophys. Res. Commun., 1997, vol. 235, pp. 545-552.
Thomas, D.J., Avenson, T.J., Thomas, J.B., and Herbert, S.K., A Cyanobacterium Lacking Iron Superoxide Dismutase Is Sensitized to Oxidative Stress Induced with Methyl Viologen but Is Not Sensitized to Oxidative Stress Induced with Norflurazon, Plant Physiol., 1998, vol. 116, pp. 1593-1602.
Tichy, M. and Vermaas, W., In vivo Role of Catalase-Peroxidase in Synechocystis sp. Strain PCC 6803, J. Bacteriol., 1999, vol. 181, pp. 1875-1882.
Cyanobase Website, http://www.kazusa.or.jp/cyano/ Synechocystis.
Sidoruk, K.V., Shakhnabatyan, L.G., Belavina, N.V., et al., Mutant Unicellular Cyanobacteria Resistant to Inhibitors Causing Oxidative Stress, Vestn. Mosk. Gos. Univ., Ser. Biol., 1996, vol. 4, pp. 43-49.
Sidoruk, K., Melnik, V., Babykin, M., et al., Cloning and Molecular Analysis of the Gene prqR Controlling Resistance to Paraquat in Synechocystis sp. PCC 6803, The Phototrophic Prokaryotes, Peschek, G.A., Loffelhardt, W., and Schmetterer, G., Eds., New York: Kluwer Academic, 1999, pp. 715-718.
Rippka, R., Deruelles, D.E., Waterbury, J.B., et al., Generic Assignments, Strain Histories and Properties of Pure Cultures of Cyanobacteria, J. Gen. Microbiol., 1979, vol. 111, pp. 1-61.
Zinchenko, V.V., Piven, I.V., Mel'nik, V.A., and Shestakov, S.V., Vectors for Complementation Analysis of Mutant Cyanobacteria, Genetika (Moscow), 1999, vol. 35, no. 2, pp. 291-296.
Sambrook, J., Fritsch, E.F., and Maniatis, T., Molecular Cloning: A Laboratory Manual, Cold Spring Harbor, New York: Cold Spring Harbor Lab., 1989.
Hillen, W. and Berens, C., Mechanisms Underlying Expression of Tn10-Encoded Tetracycline Resistance, Annu. Rev. Microbiol., 1994, vol. 48, pp. 345-369.
Yerushalmi, H. and Schuldiner, S., An Essential Glutamyl Residue in EmrE, a Multidrug Antiporter from Escherichia coli, J. Biol. Chem., 2000, vol. 275, pp. 5264-5269.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Babykin, M.M., Sidoruk, K.V., Zinchenko, V.V. et al. On the Involvement of the Regulatory Gene prqR in the Development of Resistance to Methyl Viologen in Cyanobacterium Synechocystis sp. PCC 6803. Russian Journal of Genetics 39, 18–24 (2003). https://doi.org/10.1023/A:1022010525032
Issue Date:
DOI: https://doi.org/10.1023/A:1022010525032