Understanding how glycosylation changes in concert with the circadian rhythm

Abstract

Kondoh now works with mice and is attempting to discover the relationship between the proteins produced by the circadian clock genes and the glycans that alter them. Specifically, he is looking at daily changes to the olfactory system of mice. Similar to the seasonal change in olfactory function he observed in snakes, mice alter their ‘olfactory sensitivity’ from day to night. ‘During the night, when mice are active, they can detect minute amounts of odorants from food, something they cannot do during the day and this circadian rhythm is under the regulation of so-called clock genes,’ Kondoh explains. However, the story is more complex because it isn’t really known how the protein expression of these genes is regulated by the circadian clock. For Kondoh, this is where glycans may play a role: ‘glycans seem to be an appropriate candidate for this regulation, because we know that glycosylation modulates the activity of proteins and affects the activity of neurons.’ Understanding the actual biological mechanisms controlling the hands of the circadian clock would be a great step forward. Knowing which molecules influence the functioning of processes controlled by the circadian rhythm would lead to treatments for those suffering from disruptions to the circadian clock; disruptions that cause hormonal imbalances and disorders of sleeping and eating. In this way Kondoh’s research could lead to improvements to mental and physical wellbeing.