Fig. 3.

Cross talk between the core clock mechanism and metabolic pathways. The core clock consists of a series of transcription/translation feedback loops that either directly or indirectly synchronize diverse metabolic processes. The clock also receives reciprocal input from nutrient signaling pathways (including NAD⁺-dependent sirtuins), which function as rheostats to coordinate metabolic processes with daily cycles of sleep/wakefulness and fasting/feeding [Figure modified from Bass and Takahashi (2010)]