(427d) The Cellular Circadian Clock Drives Daily Rhythms of Ion Transport

Circadian clocks are fundamental to the biology of most organisms, coordinating physiology and behaviours (such as sleep) to resonate with the environmental cycle of day and night, through complex networks of clock-controlled genes. Circadian disruption in humans, as occurs during shift work, is strongly associated with a range of chronic diseases e.g. type II diabetes, various cancers. A fundamental knowledge gap exists, however, between clock gene expression cycles and the biochemical mechanisms that ultimately imparts circadian regulation to the activity of individual cells. Using a wide range of model organisms, including human, fungal and algal cells, as well as techniques such as dielectrophoresis and inductively-coupled plasma mass spectrometry, we have observed a daily rhythm in the import/export of K⁺ and Mg²⁺ions over the cellâ??s plasma membrane. The striking evolutionary conservation of these daily rhythms of ion transport, combined with their functional consequences for cellular energy balance, suggests a fundamental yet unexplored feature of eukaryotic circadian timekeeping that has persisted from a common ancestor living >1.5 billion years ago.