[Japanese Society of Plant Physiologist Award] Circadian oscillator of cyanobacteria

DOI
  • Kondo Takao
    Division of Biological Science, Graduate School of Science, Nagoya University

Bibliographic Information

Other Title
  • 日本植物生理学会賞 シアノバクテリアの概日振動発生機構

Abstract

Cyanobacteria are the simplest organisms that exhibit circadian rhythms. In Synechococcus elongatus PCC 7942, three genes (kaiA, kaiB and kaiC) code essential components of the circadian clock. In fact, we reconstituted the temperature- compensated circadian oscillation of KaiC phosphorylation by incubating KaiC with KaiA, KaiB and ATP in test tube. Circadian period observed in vivo in various KaiC mutant strains were consistent with those measured in vitro when the incubations were carried out with the respective mutant KaiC proteins. Therefore, the oscillation of KaiC phosphorylation is the primary pacemaker of the cyanobacterial circadian clock.<br> To dissect the mechanisms of the in vitro KaiC phosphorylation cycle, we studies following aspects; 1) interaction of KaiA and KaiB to KaiC, 2) phosphorylation of two phosphorylation site, and 3) energetics of the phosphorylation cycle of KaiC. We found that KaiC has very small but temperature-compensated ATPase activity that primarily defined circadian period length.

Journal

Details 詳細情報について

  • CRID
    1390282680607643264
  • NII Article ID
    130006991884
  • DOI
    10.14841/jspp.2007.0.a001.0
  • Data Source
    • JaLC
    • CiNii Articles
  • Abstract License Flag
    Disallowed

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