Circadian coordination: understanding interplay between circadian clock and mitochondria

Biological rhythms play a crucial role in temporally regulating behavioral, physiological, and cellular processes within our bodies. One prominent example is the circadian rhythm, which enables our bodies to anticipate external cues and regulate our internal processes accordingly. The circadian rhythm is controlled by a molecular feedback loop known as the circadian clock, present in nearly all cells. The regulation of genes involved in mitochondrial function is no exception. Key aspects such as oxidative phosphorylation, mitochondrial biogenesis, and mitochondrial morphology are regulated by the circadian clock. Functional changes in mitochondria can retrogradely affect the circadian rhythm. Furthermore, there are also transcriptional circadian clock-independent rhythms within mitochondria. This review discusses mitochondrial rhythms independently or in communication with the circadian clock in the nucleus at the cellular level.