SCIENTIFIC RESEARCH

New insights into mechanism of circadian rhythms

May 2, 2023

A team of researchers from the University of Pennsylvania has identified the structure of the circadian rhythm photosensor and its target in fruit flies (Drosophila melanogaster). The research, published in the journal Nature, provides new insights into the mechanisms behind circadian rhythms, which are the 24-hour cycles that govern many biological processes, including sleep, wakefulness, and metabolism.

The researchers used innovative cryo-electron microscopy techniques to image the cryptochrome photosensor and its target, a large protein known as Timeless. They found that the two proteins interact to form a complex that regulates the expression of genes involved in circadian rhythm.

The findings provide a new understanding of how circadian rhythms are controlled and could lead to the development of new treatments for sleep disorders and other conditions that are affected by circadian rhythms.

Structure of circadian rhythm photoreceptor and target identified

Here are our key takeaways from the study: Cryptochrome–Timeless structure reveals circadian clock timing mechanisms

Circadian rhythms: 24-hour biological cycles

 

Circadian rhythms are an essential part of life. They help us to stay in sync with the day-night cycle and to function at our best. Circadian rhythms are controlled by a complex system of genes and proteins that work together to regulate our sleep-wake cycle, body temperature, hormone levels, and other important functions.

Cryptochrome: light-sensitive protein that regulates circadian rhythms

 

The cryptochrome photosensor is a protein that is found in the eye. It is sensitive to light and plays a key role in regulating circadian rhythms. When cryptochrome is exposed to light, it triggers a cascade of events that lead to the expression of genes involved in circadian rhythm. These genes then produce proteins that help to control our sleep-wake cycle, body temperature, and other important functions.

Timeless: transcription factor that binds to circadian rhythm genes

 

The Timeless protein is a transcription factor that binds to the genes that are involved in circadian rhythm. It helps to regulate the expression of these genes by turning them on and off at specific times of the day.

The Timeless protein is a transcription factor that binds to the genes that are involved in circadian rhythm. It helps to regulate the expression of these genes by turning them on and off at specific times of the day. When Timeless binds to a gene, it tells the cell to make more of the protein that is encoded by that gene. This helps to ensure that the genes involved in circadian rhythm are expressed at the right times of day.

Potential for new treatments: sleep disorders, other circadian rhythm conditions

 

The findings of the study provide a new understanding of how circadian rhythms are controlled. This knowledge could lead to the development of new treatments for sleep disorders and other conditions that are affected by circadian rhythms. For example, scientists could develop drugs that target the cryptochrome photosensor or the Timeless protein. These drugs could help to regulate circadian rhythms and improve sleep quality.

Reference: Lin C, Feng S, DeOliveira CC, Crane BR. Cryptochrome–Timeless structure reveals circadian clock timing mechanisms. Nature. 2023:1-6. doi: 10.1038/s41586-023-06009-4