Variety of DNA Replication Activity Among Cyanobacteria Correlates with Distinct Respiration Activity in the Dark.
Cyanobacteria exhibit light-dependent cell growth since most of their cellular energy is obtained by photosynthesis. In Synechococcus elongatus PCC 7942, one of the model cyanobacteria, DNA replication depends on photosynthetic electron transport. However, the critical signal for the regulatory mechanism of DNA replication has not been identified. In addition, conservation of this regulatory mechanism has not been investigated among cyanobacteria. To understand this regulatory signal and its dependence on light, we examined the regulation of DNA replication under both light and dark conditions among three model cyanobacteria, S. elongatus PCC 7942, Synechocystis sp. PCC 6803 and Anabaena sp. PCC 7120. Interestingly, DNA replication activity in Synechocystis and Anabaena was retained when cells were transferred to the dark, although it was drastically decreased in S. elongatus. Glycogen metabolism and respiration were higher in Synechocystis and Anabaena than in S. elongatus in the dark. Moreover, DNA replication activity in Synechocystis and Anabaena was reduced to the same level as that in S. elongatus by inhibition of respiratory electron transport after transfer to the dark. These results demonstrate that there is disparity in DNA replication occurring in the dark among cyanobacteria, which is caused by the difference in activity of respiratory electron transport.
Department of Bioscience, Tokyo University of Agriculture, Tokyo, Japan.|Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Tokyo, Japan.|Department of Cell Genetics, National Institute of Genetics, Shizuoka, Japan.
Ryudo
R
Ohbayashi
Department of Bioscience, Tokyo University of Agriculture, Tokyo, Japan.
Jun-Ya
JY
Yamamoto
Department of Bioscience, Tokyo University of Agriculture, Tokyo, Japan.
Satoru
S
Watanabe
Genome Research Center, Tokyo University of Agriculture, Tokyo, Japan.
Yu
Y
Kanesaki
Department of Bioscience, Tokyo University of Agriculture, Tokyo, Japan.
Taku
T
Chibazakura
Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Tokyo, Japan.|Department of Cell Genetics, National Institute of Genetics, Shizuoka, Japan.
Shin-Ya
SY
Miyagishima
Department of Bioscience, Tokyo University of Agriculture, Tokyo, Japan.|Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Tokyo, Japan.
Hirofumi
H
Yoshikawa
D000458:Cyanobacteria / Q000235:genetics / Q000378:metabolism*; D004261:DNA Replication / Q000235:genetics / Q000502:physiology; D004579:Electron Transport / Q000235:genetics / Q000502:physiology; D008027:Light; D010788:Photosynthesis / Q000235:genetics / Q000502:physiology
Cyanobacteria; DNA replication; Electron transport; Metabolism; Respiration