September 30, 2011
Alarm Clock Gene Controls When You Wake Up
Did you wake up before your alarm clock this morning? Don´t blame the neighbor´s barking dog, it may be your own genes telling you to get out of bed. Researchers at the Salk Institute for Biological Studies have identified a gene responsible for starting the your biological clock from its restful state in the morning.
Your biological clock ramps up our metabolism early each day, initiating important physiological functions that tell our bodies that it´s time to rise and shine.Discovery of this new gene highlights the genetic underpinnings of sleeplessness, aging and chronic illnesses, such as cancer and diabetes, and researchers are hoping to lead to new therapies for these illnesses.
Satchindananda Panda, an associate professor in Salk´s Regulatory Biology Laboratory, who led the research along with Luciano DiTacchio, a post-doctoral research associate says, “The body is essentially a collection of clocks.”
“We roughly knew what mechanism told the clock to wind down at night, but we didn´t know what activated us again in the morning. Now that we´ve found it, we can explore more deeply how our biological clocks malfunction as we get older and develop chronic illness.”
In a report published in the journal Science, the Salk researchers and their collaborators at McGill University and Albert Einstein College of Medicine describe how the gene KDM5A encodes a protein, JARID1a, that serves as an activation switch in the biochemical circuit that maintains our circadian rhythm.
The discovery fills in a missing link in the molecular mechanisms that control our daily wake-sleep cycle. The central player of our biological clock is a protein called PERIOD (PER). The number of PER proteins in each of our cells rises and falls every 24 hours.
Our cells use the level of PER protein as an indicator of the time of the day and tell our body when to sleep or be awake. As we age, the biological clock declines, which can cause older people to suffer difficulty sleeping and there is strong evidence that shift workers, nurses and emergency personnel working long shifts are at higher risk for certain diseases.
Diabetes, another chronic disease, is tied to metabolic cycles controlled by the biological clock. The conversion of sugars into fat, which normally occurs only at certain times of day, often seems to take place all day long in diabetics´ bodies, suggests the clock has lost control.
Daily metabolic cycles are fundamental to operation of our genetic mechanisms controlling how cells grow and divide, both in normal development and in cancer.
“So much of what it means to be healthy and youthful comes down to a good night´s sleep,” Panda says. “Now that we have identified JARID1a in activating our daytime cycle, we have a whole new avenue to explore why some people´s circadian rhythms are off and to perhaps find new ways to help them.”
Image 2: The circadian clock depicts a person's regular physiological events during certain hours of the day. Credit: Courtesy of Salk Institute for Biological Studies
Image 3: The circadian clock illustrates the many diseases that manifest in a person during certain times of the day. Credit: Courtesy of Salk Institute for Biological Studies
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