Nav: Home

What makes circadian clocks tick?

February 18, 2018

WASHINGTON, D.C., February 18, 2018 -- Circadian clocks are found within microbes and bacteria, plants and insects, animals and humans. These clocks arose as an adaptation to dramatic swings in daylight hours and temperature caused by the Earth's rotation. But we still don't fully understand how these tiny biological clocks work.

During the 62nd Biophysical Society Annual Meeting, held Feb. 17-21, in San Francisco, California, Andy LiWang at the University of California, Merced will present his lab's work studying the circadian clock of blue-green colored cyanobacteria. One type of cyanobacteria, called spirulina, is high in vitamins and minerals and is used as a natural food dye for candy and gum.

LiWang's group discovered that how the proteins move hour by hour is central to cyanobacteria's circadian clock function. "And now it's becoming clear that the same is true for eukaryotic [animal] clocks," LiWang said.

Cyanobacterial circadian clock proteins are unique because they can be reconstituted within a test tube in the absence of live cells. Researchers made a solution of these proteins and adenosine triphosphate (ATP), food for the proteins, to create a circadian clock that functioned for weeks.

LiWang's structural biology lab uses nuclear magnetic resonance (NMR) spectroscopy, the parent technology for MRI, to study the protein structure and dynamics of biological molecules and then uses the structures to gain insights into their function. "We also examine how the proteins wiggle, flex, and shape-shift, because these motions ... are also critical to their biological function," LiWang said.

LiWang's lab also collaborates with X-ray crystallographers like Carrie Partch at the University of California, Santa Cruz, because X-ray crystallography is a powerful technique to capture static structures of proteins and their complexes at atomic and near-atomic resolution.

"A big surprise for us was the extent to which internal motions of circadian clock proteins dictate ... their function," LiWang said. "Static X-ray crystal structures of individual proteins, mostly solved by other labs, were invaluable to our work but told only part of the story."

Cyanobacterial clock proteins aren't exactly the same as the clock proteins of animals or human clocks, but proteins serve as the cogs, gears and springs of all circadian clockworks and the overall function of the proteins is similar.

"Because clock proteins need to keep time, there should be some basic principles of biological timekeeping shared between all clocks regardless of whether the proteins are the same or not," LiWang said. "Our structures of the complexes of the circadian clock proteins of cyanobacteria provided important mechanistic insights, but are static snapshots of a system that's continuously moving and changing hour by hour," said LiWang.
-end-
231-Pos, Board B1 "Ticking mechanism of a biological clock" is authored by Andy LiWang. It will be displayed at 1:45 p.m. PST, Sunday, Feb. 18, 2018, in the South Hall ABC of the Moscone Center South. Abstract: https://plan.core-apps.com/bpsam2018/abstract/598979c882021290aae09439cc42e19d

ABOUT THE MEETING

Each year, the Biophysical Society Annual Meeting brings together more than 6,000 researchers working in the multidisciplinary fields representing biophysics. With more than 3,600 poster presentations, over 200 exhibits, and more than 20 symposia, the BPS Annual Meeting is the largest meeting of biophysicists in the world. Despite its size, the meeting retains its small-meeting flavor through its subgroup symposia, platform sessions, social activities and committee programs. The 62nd Annual Meeting will be held at the Moscone Center (South) in San Francisco, California.

PRESS REGISTRATION

The Biophysical Society invites professional journalists, freelance science writers and public information officers to attend its Annual Meeting free of charge. For press registration, contact Ellen Weiss at EWeiss@biophysics.org or the Media Line at the American Institute of Physics at media@aip.org or 301-209-3090.

NEWS RELEASES

Embargoed press releases describing in detail some of the breakthroughs to be discussed at the meeting are available on EurekAlert!, Newswise and Alpha Galileo or by contacting the Media Line at the American Institute of Physics at media@aip.org or 301-209-3090.

QUICK LINKS

Main Meeting Page: https://www.biophysics.org/2018meeting/Home/tabid/7117/Default.aspx Symposia: https://www.biophysics.org/2018meeting/Program/ScientificSessions/Symposia/tabid/7192/Default.aspx

Desktop Planner: http://www.biophysics.org/2018meeting/GeneralInfo/MobileApp/tabid/7473/Default.aspx

ABOUT THE SOCIETY

The Biophysical Society, founded in 1958, is a professional, scientific Society established to encourage development and dissemination of knowledge in biophysics. The Society promotes growth in this expanding field through its annual meeting, monthly journal, and committee and outreach activities. Its 9,000 members are located throughout the U.S. and the world, where they teach and conduct research in colleges, universities, laboratories, government agencies, and industry. For more information on the Society, or the 2018 Annual Meeting, visit http://www.biophysics.org.

Biophysical Society

Related Circadian Clock Articles:

How circadian clocks communicate with each other
Multiple biological clocks control the daily rhythms of physiology and behavior in animals and humans.
Circadian clock changes can alter body's response to diet
Changing the circadian clock in mouse liver can alter how the body responds to diet and also change the microbes living in the digestive track.
Red and violet light reset the circadian clock in algae via novel pathway
A Nagoya University-led team uncovered a pathway in the alga Chlamydomonas reinhardtii that resets its circadian clock on exposure to red or violet light.
TSRI researchers show how circadian 'clock' may influence cancer pathway
A new study led by scientists at The Scripps Research Institute describes an unexpected role for proteins involved with our daily 'circadian' clocks in influencing cancer growth.
Powering up the circadian rhythm
Salk team first to discover protein that controls the strength of body's circadian rhythms.
With a broken circadian clock, even a low-salt diet can raise resting blood pressure, promote disease
In the face of a disrupted circadian rhythm, a low-salt diet and a hormone known to constrict blood vessels have the same unhealthy result: elevated resting blood pressure and vascular disease, scientists report.
Bacteria engineered with synthetic circadian clocks
Many of the body's processes follow a natural daily rhythm or so-called circadian clock, so there are certain times of the day when a person is most alert, when the heart is most efficient, and when the body prefers sleep.
New research helps to explain how temperature shifts the circadian clock
One important aspect of the internal time-keeping system continues to perplex scientists: its complex response to temperature, which can shift the clock forward or backward, but cannot change its 24-hour period.
Circadian clock controls insulin and blood sugar in pancreas
A new Northwestern Medicine study has pinpointed thousands of genetic pathways an internal body clock takes to dictate how and when our pancreas must produce insulin and control blood sugar, findings that could eventually lead to new therapies for children and adults with diabetes.
Uncovering the secrets of sleep and circadian rhythms
Our circadian rhythms tell us when it's time to sleep and energize us at different times of the day; evidence suggests it also plays a role in the development of diseases such as cancer.

Related Circadian Clock Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Bias And Perception
How does bias distort our thinking, our listening, our beliefs... and even our search results? How can we fight it? This hour, TED speakers explore ideas about the unconscious biases that shape us. Guests include writer and broadcaster Yassmin Abdel-Magied, climatologist J. Marshall Shepherd, journalist Andreas Ekström, and experimental psychologist Tony Salvador.
Now Playing: Science for the People

#514 Arctic Energy (Rebroadcast)
This week we're looking at how alternative energy works in the arctic. We speak to Louie Azzolini and Linda Todd from the Arctic Energy Alliance, a non-profit helping communities reduce their energy usage and transition to more affordable and sustainable forms of energy. And the lessons they're learning along the way can help those of us further south.