TY - JOUR
T1 - Circadian formation of clock protein complexes by KaiA, KaiB, KaiC, and SasA in cyanobacteria
AU - Kageyama, Hakuto
AU - Kondo, Takao
AU - Iwasaki, Hideo
PY - 2003/1/24
Y1 - 2003/1/24
N2 - Physical interactions among clock-related proteins KaiA, KaiB, KaiC, and SasA are proposed to be important for circadian function in the cyanobacterium Synechococcus elongatus PCC 7942. Here we show that the Kai proteins and SasA form heteromultimeric protein complexes dynamically in a circadian fashion. KaiC forms protein complexes of ∼350 and 400-600 kDa during the subjective day and night, respectively, and serves as a core of the circadian protein complexes. This change in the size of the KaiC-containing complex is accompanied by nighttime-specific interaction of KaiA and KaiB with KaiC. In various arrhythmic mutants that lack each functional Kai protein or SasA, circadian rhythms in formation of the clock protein complex are abolished, and the size of the protein complexes is dramatically affected. Thus, circadian-regulated formation of the clock protein complexes is probably a critical process in the generation of circadian rhythm in cyanobacteria.
AB - Physical interactions among clock-related proteins KaiA, KaiB, KaiC, and SasA are proposed to be important for circadian function in the cyanobacterium Synechococcus elongatus PCC 7942. Here we show that the Kai proteins and SasA form heteromultimeric protein complexes dynamically in a circadian fashion. KaiC forms protein complexes of ∼350 and 400-600 kDa during the subjective day and night, respectively, and serves as a core of the circadian protein complexes. This change in the size of the KaiC-containing complex is accompanied by nighttime-specific interaction of KaiA and KaiB with KaiC. In various arrhythmic mutants that lack each functional Kai protein or SasA, circadian rhythms in formation of the clock protein complex are abolished, and the size of the protein complexes is dramatically affected. Thus, circadian-regulated formation of the clock protein complexes is probably a critical process in the generation of circadian rhythm in cyanobacteria.
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U2 - 10.1074/jbc.M208899200
DO - 10.1074/jbc.M208899200
M3 - Article
C2 - 12441347
AN - SCOPUS:0037462789
VL - 278
SP - 2388
EP - 2395
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 4
ER -