Navigation Links
New research provides dynamic visualization of simplest circadian clock
Date:3/13/2008

Scientists have acquired a more dynamic picture of events that underlie the functions of a bacterial biological clock. New research published online March 13th by Cell Press in the journal Molecular Cell, shows how the simplest organism known to have a circadian clock keeps time and may enhance our understanding of how other organisms establish and govern chronological rhythms.

A variety of organisms have evolved endogenous timing systems called a circadian clock that allows them to regulate metabolic activities in a day/night cycle. The simplest organisms known to possess a circadian oscillator are the cyanobacteria, better known as blue-green algae. The essential components of the circadian oscillator in cyanobacteria are the three clock proteins KaiA, KaiB and KaiC, all of which are expressed in the cyanobacterium S. elongatus.

Considerable research has implicated the phosphorylation cycle of KaiC as the central pacemaker in cyanobacteria and has demonstrated that the Kai proteins are repeatedly assembled and disassembled into heteromultimeric complexes, termed periodosomes. The crystal structure of each clock protein has also been determined and analyzed.

Despite the substantial progress in structural characterization, the relationship between the assembly/disassembly dynamics and the circadian phosphorylation of KaiC is still poorly understood, mainly because of the difficulty in unraveling the underlying mechanisms solely from the static molecular pictures of individual clock components, explains Dr. Akiyama from the Japan Science and Technology Agency.

To obtain a more complete visualization of the cyanobacterial circadian oscillator, Dr. Akiyama and colleagues used small-angle X-ray scattering (SAXS) to follow the assembly/disassembly dynamics of the S. elongatus heteromultimeric Kai complexes in real time. The researchers found that the assembly/disassembly processes are crucial for phase entrainment in the early synchronizing stage but are passively driven by the phosphorylation status of KaiC in the late oscillatory stage. Further, KaiA and KaiB are recruited to KaiC in a phosphorylation-dependent manner.

Our findings demonstrate that the initial phase of the cyanobacterial oscillator is determined predominantly by the assembly/disassembly communication of the clock components, and that the period is essentially resistant to intracellular noise such as collisions, cytoplasmic viscosity and crowding. These resistances are achieved in the binary and ternary complexes by recruiting KaiA homodimers, KaiB homotetramers and KaiC homohexamers in a phosphorylation-dependent manner, concludes Dr. Akiyama.


'/>"/>
Contact: Cathleen Genova
cgenova@cell.com
617-397-2802
Cell Press
Source:Eurekalert

Related medicine news :

1. Study in Circulation Research details how diabetes drives atherosclerosis
2. MassMutuals Center for Behavioral Research(sm) Releases White Paper Regarding Automatic Features in Retirement Plans
3. VA Research Project on NASA Space Shuttle
4. Researchers confirm link between common cold and ear infection
5. Researchers make case for standardized analysis of cardiac imaging
6. Researchers find cause of severe allergic reaction to cancer drug
7. $2.1 million NIH grant advances U-Iowa child health research
8. Research could put penicillin back in battle against antibiotic resistant bugs that kill millions
9. Early bird doesnt always get worm, UNC researcher finds
10. Researchers develop a method to select eggs with the best chance of leading to successful pregnancy
11. USC researchers find benefit for lymphoma patients in combined PET-CT scanning
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:10/13/2017)... NY (PRWEB) , ... October 13, 2017 , ... Ellevate ... people in business to advocate for action towards gender equality at their inaugural Summit ... from around the globe, and reached a social audience of over 3 million. To ...
(Date:10/13/2017)... Fairfax, VA (PRWEB) , ... October 13, 2017 ... ... provider of DevOps and Agile Software Development, has been awarded a contract by ... (EATS) Blanket Purchase Agreement (BPA) aims to accelerate the enterprise use of Agile ...
(Date:10/12/2017)... ... October 12, 2017 , ... ... treating sleep apnea using cutting-edge Oventus O2Vent technology. As many as ... disorder characterized by frequent cessation in breathing. Oral appliances can offer significant relief ...
(Date:10/12/2017)... ... October 12, 2017 , ... The American College of Medical Informatics ... PhD, FACMI, during the Opening Session of AMIA’s Annual Symposium in Washington, D.C. AMIA’s ... of Morris F. Collen, a pioneer in the field of medical informatics, this prestigious ...
(Date:10/12/2017)... ... ... HMP , a leader in healthcare events and education, today announced that ... for ‘Best B-to-B Healthcare Website.’ Winners were announced during the Eddie & Ozzie Awards ... recognizes editorial and design excellence across a range of sectors. This year’s program included ...
Breaking Medicine News(10 mins):
(Date:10/2/2017)... , Oct. 2, 2017  AllianceRx Walgreens Prime, ... formed by Walgreens and pharmacy benefit manager Prime Therapeutics ... new brand, which included the unveiling of new signage ... , as well as at a few other company-owned ... new brand to patients, some of whom will begin ...
(Date:9/27/2017)... , Sept. 27, 2017  Commended for their devotion ... notable awards. Ranked as number one in the South Florida ... time in Inc. 5000 yearly list, the national specialty pharmacy ... Armando Bardisa will soon be honored by SFBJ ... Set to receive his award in ...
(Date:9/22/2017)... 2017  As the latest Obamacare repeal effort moves ... (R-LA) and Lindsey Graham (R-SC) medical ... device industry is in an odd place.  The industry ... excise tax on medical device sales passed along with ... patients, increased visits and hospital customers with the funding ...
Breaking Medicine Technology: