From:  Circadian rhythm modulation in metabolic disease: targeting clock genes for obesity and insulin resistance

 Key clock genes and their metabolic roles.

GenePrimary functionMetabolic roleDysregulation effect
CLOCKTranscription factorGlucose homeostasis, lipid metabolismObesity, insulin resistance
BMAL1Transcription factorCircadian regulation of insulinHyperglycemia, fatty liver
PER1/2Feedback repressorsAppetite, energy expenditureAltered feeding rhythm, metabolic syndrome
CRY1/2Feedback repressorsHepatic gluconeogenesisHyperglycemia, insulin resistance

BMAL1: brain and muscle ARNT-like 1; CLOCK: circadian locomotor output cycles kaput; CRY1/2: cryptochrome 1 and 2; PER1/2: period gene 1 and 2.