Canadian scientists have discovered the molecular switch that resets and synchronises our internal body clock, and targeting it could help treat a range of disorders, such as insomnia, depression and obesity, that are triggered when our sleep patterns get out of whack, or when we’re exposed to light when we shouldn’t be (hello, screen checking at 1am). It’s already well established that light naturally controls these circadian rhythms, but scientists have struggled to work out exactly how it does this – until now.
The new research has shown that light resets our body clocks by triggering phosphate to combine with a key brain protein called eIF4E. This process is known as phosphorylation, and by ‘hijacking’ it, the researchers suggest it could help our bodies keep up with the pace of the 21st century. “This study is the first to reveal a mechanism that explains how light regulates protein synthesis in the brain, and how this affects the function of the circadian clock,” said lead researcher Nahum Sonenberg, a biochemist from McGill University in Quebec, in a press release.
To work out what was going on, Sonenberg’s team mutated the eIF4E protein in the brains of lab mice, so that it couldn’t be phosphorylated. They then studied the mice’s activity levels, which are controlled by their internal body clocks, as they adjusted the artificial day and night in the lab from 12-hour cycles to 10.5-hour shifts of light and dark. Usually, mice – and humans – would be able to adapt to this new rhythm quite quickly, thanks to this inbuilt reset switch. But with eIF4E phosphorylation blocked, the mice were jet-lagged in their old routine. They then investigated the pathway further, and found that phosphorylation of eIF4E increased the production of Period proteins, important proteins that are known to play a role in synchronising the body’s circadian clock. Obviously this research was conducted in mice, not humans, but all mammals have very similar circadian clocks, and so the results give a good indication of the process in our own brains.
The research has now been published in Nature Neuroscience. Importantly, it highlights a potential pathway that future drugs could target – although the researchers stress that we’re still a long way off that. Source: Scientists have found a reset “button” for our body clock