 |
|
Researchers propose new molecule to explain circadian clock
August 28, 2007The internal clock in living beings that regulates sleeping and waking patterns -- usually called the circadian clock -- has often befuddled scientists due to its mysterious time delays. Molecular interactions that regulate the circadian clock happen within milliseconds, yet the body clock resets about every 24 hours. What, then, stretches the expression of the clock over such a relatively long period?
Cornell researchers have contributed to the answer, thanks to new mathematical models recently published.
In the August online edition of Public Library of Science (PLOS) Computational Biology, Cornell biomolecular engineer Kelvin Lee, in collaboration with graduate student Robert S. Kuczenski, Kevin C. Hong '05 and Jordi Garcia-Ojalvo of Universitat Politecnica de Catalunya, Spain, hypothesize that the accepted model of circadian rhythmicity may be missing a key link, based on a mathematical model of what happens during the sleeping/waking cycle in fruit flies.
"We didn't discover any new proteins or genes," Lee said. "We took all the existing knowledge, and we tried to organize it."
Using mathematical models initially created by Hong, who has since graduated, the team set out to map the molecular interactions of proteins called period and timeless -- widely known to be related to the circadian clock.
The group hypothesized that an extra, unknown protein would need to be inserted into the cycle with period and timeless, a molecule that Kuczenski named the focus-binding mediator, in order for the cycle to stretch to 24 hours.
Lee said many scientists are interested in studying the circadian clock, and not just to understand such concepts as jet lag -- fatigue induced by traveling across time zones. Understanding the body's biological cycle might, for example, lead to better timing of delivering chemotherapy, when the body would be most receptive, Lee said.
Cornell University
"We didn't discover any new proteins or genes," Lee said. "We took all the existing knowledge, and we tried to organize it."
Using mathematical models initially created by Hong, who has since graduated, the team set out to map the molecular interactions of proteins called period and timeless -- widely known to be related to the circadian clock.
The group hypothesized that an extra, unknown protein would need to be inserted into the cycle with period and timeless, a molecule that Kuczenski named the focus-binding mediator, in order for the cycle to stretch to 24 hours.
Lee said many scientists are interested in studying the circadian clock, and not just to understand such concepts as jet lag -- fatigue induced by traveling across time zones. Understanding the body's biological cycle might, for example, lead to better timing of delivering chemotherapy, when the body would be most receptive, Lee said.
Cornell University
Circadian Clock Current Events and Circadian Clock News RSSBright lights, not-so-big pupils
A team of Johns Hopkins neuroscientists has worked out how some newly discovered light sensors in the eye detect light and communicate with the brain. The report appears online this week in Nature.
Another reason to avoid high-fat diet -- it can disrupt our biological clock
Indulgence in a high-fat diet can not only lead to overweight because of excessive calorie intake, but also can affect the balance of circadian rhythms - everyone's 24-hour biological clock, Hebrew University of Jerusalem researchers have shown.
New genes present drug targets for managing cholesterol and glucose levels
Scientists have identified 12 new genes that are somewhat strange bedfellows: Some link gallstones and blood cholesterol levels, others link melatonin and sleep patterns to small increases in glucose levels and larger jumps in the risk of diabetes.
Plants grow bigger and more vigorously through changes in their internal clocks
Hybrid plants, like corn, grow bigger and better than their parents because many of their genes for photosynthesis and starch metabolism are more active during the day, report researchers from The University of Texas at Austin in a new study published in the journal Nature.
Circadian clock may be critical for remembering what you learn, Stanford researchers say
The circadian rhythm that quietly pulses inside us all, guiding our daily cycle from sleep to wakefulness and back to sleep again, may be doing much more than just that simple metronomic task, according to Stanford researchers.
Mom's mood, baby's sleep: what's the connection?
If there's one thing that everyone knows about newborn babies, it's that they don't sleep through the night, and neither do their parents.
Phase of clock gene expression in human leukocytes correlates with habitual sleep timing
The phase of clock gene expression in leukocytes, assessed in the absence of the masking effects of light-dark and sleep-wake cycles, correlates with habitual sleep timing, according to a study published in the May 1 issue of the journal SLEEP.
Seasonal weight changes linked to metabolic syndrome
Seasonal changes in weight increase the risk for metabolic syndrome, a group of scientists from National Public Health Institute, Helsinki, Finland, reports in a study published in the January 23 issue of the online, open-access journal PLoS ONE.
Scientists unravel the molecular basis of monarch butterfly migration
Since its discovery, the annual migration of eastern North American monarch butterfly has captivated the human imagination and spirit. That millions of butterflies annually fly up to 2000 miles to reach a cluster of pine groves in central Mexico comprising just 70 square miles is for many an awesome and mysterious occurrence.
Not just humans benefit from animal biotechnology
Laboratory animals are the source of major discoveries and breakthroughs in biology, not just in tackling disease but also unravelling fundamental molecular processes. Delegates at a recent research conference organised by the European Science Foundation (ESF) and Wellcome Trust heard how technology capable of analysing animal genes across the whole genome is yielding many benefits for agriculture and human society.
More Circadian Clock Current Events and Circadian Clock News Articles
 | Rhythms of Life: The Biological Clocks that Control the Daily Lives of Every Living Thing by Russell G. Foster, Leon Kreitzman Why can’t teenagers get out of bed in the morning? How do bees tell the time? Why do some plants open and close their flowers at the same time each day? Why do so many people suffer the misery of jet lag? In this fascinating book, Russell Foster and Leon Kreitzman explain the significance of the biological clock, showing how it has played an essential role in evolution and why it continues to... |
 | Handbook of Behavioral Neurobiology, Volume 12: Circadian Clocks (Handbooks of Behavioral Neurobiology) The Handbook of Behavioral Neurobiology series deals with the aspects of neurosciences that have the most direct and immediate bearing on behavior. It presents the most current research available in the specific areas of sensory modalities. This volume explores circadian... |
| Endocrine Rhythms: Roles of the Sleep-Wake Cycle, the Circadian Clock & the Environment: Diagnostic & Therapeutic Implications 40th International Henri-Pierre Klotz (Hormone Research, 3-4) | |
| Developmental Alcohol and Circadian Clock Function.: An article from: Alcohol Research & Health by David J. Earnest, Wei-jung A. Chen, James R. West This digital document is an article from Alcohol Research & Health, published by U.S. Government Printing Office on March 22, 2001. The length of the article is 3429 words. The page length shown above is based on a typical 300-word page. The article is delivered in HTML format and is available in your Amazon.com Digital Locker immediately after purchase. You can view it with any web... | |
| The Physiological Clock: Circadian Rhythms and Biological Chronometry (Graduate Texts in Mathematics,) by Erwin Bunning | |
 | Circadian Clocks and Their Adjustment - No. 183 (CIBA Foundation Symposia Series) by CIBA Foundation Symposium Circadian Clocks and Their Adjustment Chairman: J. M. Waterhouse 1995 Organisms ranging from unicellular algae to humans display biological rhythms reflecting their ability at the molecular level to keep track of time. In humans, the circadian clock signals when to sleep and wake, adjusts body temperature and modifies cardiovascular, renal, digestive and other functions, correspondingly directing... |
| Circadian Clocks: Proceedings of the Feldafing Summer School, 7-18 September 1964 | |
 | Bacterial Circadian Programs Since the discovery of circadian rhythms in cyanobacteria in the late 1980s, the field has exploded with new information. The cyanobacterial model system for studying circadian rhythms, Synechococcus elongatus, has allowed a detailed genetic dissection of the bacterial clock due to the methods currently available in molecular, structural, and evolutionary biology. This book addresses multiple... |
 | The Clocks That Time Us: Physiology of the Circadian Timing System (Commonwealth Fund Publications) by Martin C. Moore-Ede, Frank M. Sulzman, Charles A. Fuller |
| The physiological clock (The Heidelberg science library) by Erwin BuÌnning |
| © 2009 BrightSurf.com |