title: Reconstitution of circadian oscillation of cyanobacterial KaiC phosphorylation in vitro.
abstract: Kai proteins globally regulate circadian gene expression of cyanobacteria. The KaiC phosphorylation cycle, which persists even without transcription or translation, is assumed to be a basic timing process of the circadian clock. We have reconstituted the self-sustainable oscillation of KaiC phosphorylation in vitro by incubating KaiC with KaiA, KaiB, and adenosine triphosphate. The period of the in vitro oscillation was stable despite temperature change (temperature compensation), and the circadian periods observed in vivo in KaiC mutant strains were consistent with those measured in vitro. The enigma of the circadian clock can now be studied in vitro by examining the interactions between three Kai proteins.
authors.affiliation: Division of Biological Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Nakajima
authors.forename: Keiko
authors.initials: K
authors.lastname: Imai
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ito
authors.forename: Taeko
authors.initials: T
authors.lastname: Nishiwaki
authors.forename: Yoriko
authors.initials: Y
authors.lastname: Murayama
authors.forename: Hideo
authors.initials: H
authors.lastname: Iwasaki
authors.forename: Tokitaka
authors.initials: T
authors.lastname: Oyama
authors.forename: Takao
authors.initials: T
authors.lastname: Kondo
mesh_terms: D000255:Adenosine Triphosphate; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002940:Circadian Rhythm; D056925:Circadian Rhythm Signaling Peptides and Proteins; D005798:Genes, Bacterial; D049449:Luminescence; D009154:Mutation; D010766:Phosphorylation; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D046940:Synechococcus / Q000235:genetics / Q000378:metabolism*; D013696:Temperature
chemical_list: D001426:Bacterial Proteins; D056925:Circadian Rhythm Signaling Peptides and Proteins; C114269:KaiA protein, cyanobacteria; C114270:KaiB protein, cyanobacteria; C114271:KaiC protein, cyanobacteria; D011994:Recombinant Proteins; D000255:Adenosine Triphosphate