Researchers Discover Protein Associated with Shift Work Disorders, Jet- Lag

Researchers have found a protein linked with shift work disorders and jet-lag. The discovery could pave way for newer therapeutics that could correct the body clock.

The study conducted by researchers at University of Notre Dame and colleagues found that the protein SIK1 prevents the body from adjusting its circadian rhythm too quickly.

"It would appear that SIK1 plays a common role in our circadian clocks found throughout our body, and works as a hand-brake on our ability to shift our biorhythms and adjust to new time zones, whether these are real or artificial, such as those produced during shift work schedules," said Giles Duffield, associate professor of biological sciences at Notre Dame and one of the study authors.

The circadian rhythm or the internal clock helps all living organisms synchronize their activities according to 24-hour cycle of day and night. Travelling to other time-zones or taking up shifts can dramatically alter the clock and confuse the body. Common signs of an altered internal clock cycle include fatigue, nausea, indigestion and poor brain function.

For the study, researchers looked at the function of over 100 genes that switch-on in response to light and start a series of events to help the body adjust to light. They found that a gene that codes for the protein SIK1 prevented the body from adjusting its biological clock.

In one of the experiments, researchers blocked the activity of the gene linked with SIK1 in mice, which resulted in the mice quickly adjusting to altered light-dark cycle.

"Our key contribution to the project was to manipulate the SIK1 protein pharmacologically, and we revealed that such blockage of the protein's activity in combination with exposure to a natural clock resetting agent, such as light, enhanced the clock shifting response," Duffield said. "For example, a one-hour shift of the clock became two hours. We also showed this effect in both peripheral tissues as well as in the clock in the brain," Duffield added, according to a news release.

Previous research has linked taking up night shifts with higher risk of heart disease and breast cancer. Recent estimates suggest some 2000 cases of cancers in the U.K. were due to working night shifts. According to 2004 data from the Bureau of Labor Statistics, almost 15 million Americans work full time on evening shifts, night shifts, or other employer arranged irregular schedules.

The study is published in the journal Cell.