Period circadian regulator 3 (PER3)

Period circadian regulator 3 (PER3) is a transcription factor and clock gene that encodes a protein component of the mammalian circadian timing system[1][3][5]. PER3 is structurally related to PER1 and PER2 and is expressed rhythmically in the suprachiasmatic nucleus and peripheral tissues[1][3]. While not essential for maintaining basic circadian rhythms—unlike PER1 and PER2—it contributes to sleep-wake timing, sleep homeostasis, and the regulation of physiological rhythms such as metabolism and behavior[1][3][5]. Polymorphisms in PER3 (notably a variable-number tandem repeat in exon 18) are associated with individual differences in sleep phase preference, vulnerability to sleep deprivation, and diseases including delayed sleep phase syndrome, advanced sleep phase syndrome, type 2 diabetes mellitus, severe obesity, and some neuropsychiatric disorders[3][4][5]. Functionally, PER3 has also been shown to regulate cell fate decisions, particularly inhibiting adipogenesis in mesenchymal stem cells, potentially linking circadian regulation to metabolic outcomes[2][3]. Despite its role in the molecular feedback loops that establish circadian rhythms, PER3's influence is less pronounced than its paralogs PER1 and PER2, and its unique contributions may involve both circadian and non-circadian regulatory pathways[4][6]. There are currently no known drugs specifically targeting PER3, and it is not considered a direct therapeutic target, but its genetic variants may serve as biomarkers for sleep and metabolic disorders[3][5].

Other names

Period circadian protein homolog 3GIG13hPER3Cell growth-inhibiting gene 13 proteinCircadian clock protein PERIOD 3FASPS3period circadian clock 3period circadian protein 3