Publication Date:
2004-11-20
Description:
An autoregulatory transcription-translation feedback loop is thought to be essential in generating circadian rhythms in any model organism. In the cyanobacterium Synechococcus elongatus, the essential clock protein KaiC is proposed to form this type of transcriptional negative feedback. Nevertheless, we demonstrate here temperature-compensated, robust circadian cycling of KaiC phosphorylation even without kaiBC messenger RNA accumulation under continuous dark conditions. This rhythm persisted in the presence of a transcription or translation inhibitor. Moreover, kinetic profiles in the ratio of KaiC autophosphorylation-dephosphorylation were also temperature compensated in vitro. Thus, the cyanobacterial clock can keep time independent of de novo transcription and translation processes.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Tomita, Jun -- Nakajima, Masato -- Kondo, Takao -- Iwasaki, Hideo -- New York, N.Y. -- Science. 2005 Jan 14;307(5707):251-4. Epub 2004 Nov 18.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Division of Biological Science, Graduate School of Science, Nagoya University, and Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/15550625" target="_blank"〉PubMed〈/a〉
Keywords:
Bacterial Proteins/biosynthesis/*metabolism
;
*Circadian Rhythm
;
Circadian Rhythm Signaling Peptides and Proteins
;
Darkness
;
Feedback, Physiological
;
Light
;
Mutation
;
Operon
;
Phosphorylation
;
Protein Biosynthesis
;
RNA, Bacterial/metabolism
;
RNA, Messenger/metabolism
;
Recombinant Proteins/metabolism
;
Synechococcus/*genetics/*metabolism
;
Temperature
;
Transcription, Genetic
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
