Traveling across different continents or time zones by airplane comes with a cost. Forget the ticket price; this is about the unpleasant experience of jet lag. Jet lag happens due to disruption of your body’s internal clock, which is called “circadian rhythms.” This clock tells your body when to go to sleep or when to wake up. When you travel to a different time zone, your internal clock is still synced to your original time zone. This incompatibility of the internal clock with the external clock causes problems such as insomnia. However, it is not just that. For those who traveled a lot, jet lag can cause more severe problems such as metabolic disorders. Scientists have known for a while that there is a relationship between circadian rhythms and physiological functions such as metabolism, but the underlying mechanism is poorly understood. Now, a team of scientists from Turkey and the USA has reported a link between two genes related to metabolism and circadian rhythms.
According to the results published in The FEBS journal, a central enzyme in one-carbon metabolism (cystathionine b-synthase or CBS) “functionally interacts” with another protein called cryptochrome-1 or CRY1, which has a crucial role in circadian rhythms of the body. One-carbon metabolism consists of metabolic pathways which are central to cellular function, and its malfunction causes metabolic disorders. The new finding indicates the relationship between circadian rhythms and metabolism through CBS-CRY1 interaction. “Circadian rhythms control a wide variety of physiological events, including metabolism, in all organisms,” Told us Ibrahim Halil Kavakli, the corresponding author of the study from the Department of Chemical and Biological Engineering, Koc University, Turkey, via email.
The origins
The requirements of modern society have changed our lifestyle dramatically. Our eating, sleeping, and even physical activity habits are so different from what our ancestors were accustomed to throughout the history of human evolution. Now, we eat or sleep differently compared to what our body naturally adapted to. Although these changes enable us to thrive in a modern lifestyle, they have consequences. “Ingrained in our modern lifestyle is the flexibility to eat, sleep, socialize, and exercise around the clock, yet these allowances correlate with rising metabolic disorders and obesity,” Kavakli says. Despite this knowledge, we do not know how these changes in our lifestyle affect our body function. “It has become increasingly evident that metabolic homeostasis at the system level relies on accurate and collaborative circadian timing within individual cells and tissues of the body,” he explains. “At the center of these rhythms resides the circadian clock machinery, an incredibly well-coordinated transcription-translation feedback system that incorporates a changing landscape of mRNA expression, protein stability, chromatin state, and metabolite production utilization, and turnover to keep correct time.”