Studying a human circadian mutation reveals how the PER2 protein helps control the body’s internal clock

A mutation in the human Period 2 gene is associated with familial advanced sleep phase syndrome.

• Familial advanced sleep phase syndrome (FASPS) is linked to a specific mutation in the hPER2 gene.
• The FASPS hPER2 S662G mutation results in decreased phosphorylation of PER2 by casein kinase I in laboratory conditions.
• Transgenic mice with the FASPS hPER2 S662G mutation display characteristics similar to the human condition.
• Increased phosphorylation at the S662 site is associated with higher levels of PER2 transcription.
• Another phosphorylation site may lead to the degradation of PER2.
• Changes in CKIdelta levels can influence the circadian period through effects on PER2 in living organisms.

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