A two-component Mn2+-sensing 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 cytoplasmic Mn(2+) 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 Mn(2+) ions, and a response regulator, ManR, which might regulate the expression of the mntCAB operon for the ABC-type transporter of Mn(2+) 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 mntCAB operon. At low concentrations of Mn(2+) ions, ManS does not generate a signal, with resulting inactivation of ManR and subsequent expression of the mntCAB operon.
Yamaguchi
Katsushi
K
Department of Regulation Biology, National Institute for Basic Biology, Okazaki 444-8585, Japan.
Suzuki
Iwane
I
Yamamoto
Hiroshi
H
Lyukevich
Alexander
A
Bodrova
Irina
I
Los
Dmitry A
DA
Piven
Irina
I
Zinchenko
Vladislav
V
Kanehisa
Minoru
M
Murata
Norio
N
D018528:ATP-Binding Cassette Transporters / Q000235:genetics*; D000595:Amino Acid Sequence; D001426:Bacterial Proteins; D000458:Cyanobacteria / Q000235:genetics* / Q000502:physiology; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics / Q000502:physiology; D005816:Genetic Complementation Test; D008345:Manganese / Q000494:pharmacology*; D008969:Molecular Sequence Data; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D009876:Operon; D045332:Photosystem II Protein Complex; D011506:Proteins / Q000235:genetics* / Q000502:physiology; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics
D018528:ATP-Binding Cassette Transporters; D001426:Bacterial Proteins; C119581:MntB protein, Synechocystis; D045332:Photosystem II Protein Complex; D011506:Proteins; C054266:photosystem II manganese-stabilizing protein; D008345:Manganese