A Two-Component Mn2⁺ System Negatively Regulates Expression of the mntCAB Operon in Synechocystis

Mn is an essential component of the oxygen-evolving machinery of photosynthesis and is an essential cofactor of several important enzymes, such as Mn-superoxide dismutase and Mn-catalase. The availability of Mn in the environment varies, and little is known about the mechanisms for maintaining cytop...

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Published inThe Plant cell Vol. 14; no. 11; pp. 2901 - 2913
Main Authors Yamaguchi, Katsushi, Suzuki, Iwane, Yamamoto, Hiroshi, Lyukevich, Alexander, Bodrova, Irina, Los, Dmitry A., Piven, Irina, Zinchenko, Vladislav, Kanehisa, Minoru, Murata, Norio
Format Journal Article
LanguageEnglish
Published American Society of Plant Biologists 01.11.2002
Subjects
Amino acids
DNA
Gene expression
Genes
Genetic mutation
Operons
Plant cells
Polymerase chain reaction
Regulator genes
Sensors
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Summary:Mn is an essential component of the oxygen-evolving machinery of photosynthesis and is an essential cofactor of several important enzymes, such as Mn-superoxide dismutase and Mn-catalase. The availability of Mn in the environment varies, and little is known about the mechanisms for maintaining cytoplasmic Mn2+ ion homeostasis. Using a DNA microarray, we screened knockout libraries of His kinases and response regulators of Synechocystis sp PCC 6803 to identify possible participants in this process. We identified a His kinase, ManS, which might sense the extracellular concentration of Mn2+ ions, and a response regulator, ManR, which might regulate the expression of the mntCAB operon for the ABC-type transporter of Mn2+ ions. Furthermore, analysis with the DNA microarray and by reverse transcription PCR suggested that ManS produces a signal that activates ManR, which represses the expression of the mnt-CAB operon. At low concentrations of Mn2+ ions, ManS does not generate a signal, with resulting inactivation of ManR and subsequent expression of the mntCAB operon.
ISSN:1040-4651
1532-298X