气候变化领域集成服务门户(CCPortal): Reconstitution of an intact clock reveals mechanisms of circadian timekeeping

CCPortal

DOI	10.1126/science.abd4453
	Reconstitution of an intact clock reveals mechanisms of circadian timekeeping
	Chavan A.G.; Swan J.A.; Heisler J.; Sancar C.; Ernst D.C.; Fang M.; Palacios J.G.; Spangler R.K.; Bagshaw C.R.; Tripathi S.; Crosby P.; Golden S.S.; Partch C.L.; LiWang A.
发表日期	2021
ISSN	0036-8075
卷号	374 期号:6564
英文摘要	Circadian clocks control gene expression to provide an internal representation of local time. We report reconstitution of a complete cyanobacterial circadian clock in vitro, including the central oscillator, signal transduction pathways, downstream transcription factor, and promoter DNA. The entire system oscillates autonomously and remains phase coherent for many days with a fluorescence-based readout that enables real-time observation of each component simultaneously without user intervention. We identified the molecular basis for loss of cycling in an arrhythmic mutant and explored fundamental mechanisms of timekeeping in the cyanobacterial clock. We find that SasA, a circadian sensor histidine kinase associated with clock output, engages directly with KaiB on the KaiC hexamer to regulate period and amplitude of the central oscillator. SasA uses structural mimicry to cooperatively recruit the rare, fold-switched conformation of KaiB to the KaiC hexamer to form the nighttime repressive complex and enhance rhythmicity of the oscillator, particularly under limiting concentrations of KaiB. Thus, the expanded in vitro clock reveals previously unknown mechanisms by which the circadian system of cyanobacteria maintains the pace and rhythmicity under variable protein concentrations. © 2021 American Association for the Advancement of Science. All rights reserved.
英文关键词	protein histidine kinase; protein SasA; transcription factor; unclassified drug; bacterial protein; CikA protein, bacteria; circadian rhythm signaling protein; KaiB protein, cyanobacteria; KaiC protein, cyanobacteria; phosphotransferase; protein kinase; SasA protein, Synechococcus; circadian rhythm; concentration (composition); cyanobacterium; DNA; enzyme activity; gene expression; protein; Article; bacterial gene; circadian rhythm; cyanobacterium; fluorescence; in vitro study; KaiB gene; KaiC gene; nonhuman; oscillation; promoter region; protein conformation; signal transduction; chemistry; circadian rhythm; gene expression regulation; genetic transcription; genetics; metabolism; molecular mimicry; mutation; physiology; protein domain; protein folding; protein multimerization; Synechococcus; Cyanobacteria; Bacterial Proteins; Circadian Rhythm; Circadian Rhythm Signaling Peptides and Proteins; Gene Expression Regulation, Bacterial; Molecular Mimicry; Mutation; Phosphotransferases; Promoter Regions, Genetic; Protein Domains; Protein Folding; Protein Kinases; Protein Multimerization; Synechococcus; Transcription, Genetic
语种	英语
来源期刊	Science
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/243282
作者单位	School of Natural Sciences, University of California, Merced, CA 95343, United States; Department of Chemistry and Biochemistry, University of California, Santa Cruz, CA 95064, United States; Department of Chemistry and Biochemistry, University of California, Merced, CA 95343, United States; Center for Circadian Biology, University of California, San Diego, San diego, CA 92093, United States; Division of Biological Sciences, University of California, San Diego, San diego, CA 92093, United States; Center for Cellular and Biomolecular Machines, University of California, Merced, CA 95343, United States; Health Sciences Research Institute, University of California, Merced, CA 95343, United States
推荐引用方式 GB/T 7714	Chavan A.G.,Swan J.A.,Heisler J.,et al. Reconstitution of an intact clock reveals mechanisms of circadian timekeeping[J],2021,374(6564).
APA	Chavan A.G..,Swan J.A..,Heisler J..,Sancar C..,Ernst D.C..,...&LiWang A..(2021).Reconstitution of an intact clock reveals mechanisms of circadian timekeeping.Science,374(6564).
MLA	Chavan A.G.,et al."Reconstitution of an intact clock reveals mechanisms of circadian timekeeping".Science 374.6564(2021).