Wake-sleep cycles are severely disrupted by diseases affecting cytoplasmic homeostasis.
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Conditions such as obesity, ageing and some neurodegenerative disorders can disrupt our sleep patterns by causing ‘traffic jams’ in a cell’s cytoplasm.
Our circadian rhythm controls when we fall asleep and wake up by generating 24-hour fluctuation in levels of a pacemaker protein called PERIOD (PER). Molecular disruptions related to PER can disrupt sleep patterns, although exactly how this occurs was unclear.
Now, a team led by researchers at KAIST in South Korea has uncovered the mechanism by which PER accumulation affects circadian rhythm.
By using a mathematical model and experiments, they found that sleep–wake cycles are lengthened when trafficking of PER is disrupted by an increase in congestion of cytoplasm—an effect that occurs in several neurodegenerative and metabolic diseases.
This finding provides insight into how disease and ageing may affect our sleep patterns.
- PNAS 45, 28402–28411 (2020). doi: 10.1073/pnas.2003524117