Open AccessA Two-Component Mn2+-Sensing System Negatively Regulates Expression of the mntCAB Operon in Synechocystis
Author(s) -
Katsushi Yamaguchi,
Iwane Suzuki,
Hiroshi Yamamoto,
Alexander A. Lyukevich,
Irina Bodrova,
Dmitry A. Los,
Irina Piven,
В.В. Зинченко,
Minoru Kanehisa,
Norio Murata
Publication year - 2002
Publication title -
the plant cell
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.324
H-Index - 341
eISSN - 1532-298X
pISSN - 1040-4651
DOI - 10.1105/tpc.006262
Subject(s) - operon , biology , two component regulatory system , synechocystis , biochemistry , enzyme , regulon , kinase , gene expression , transcription (linguistics) , extracellular , microbiology and biotechnology , gene , mutant , linguistics , philosophy
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.