Description
Period circadian protein homolog 2 is a member of the Period family of proteins and is expressed in a circadian pattern in the suprachiasmatic nucleus, the primary circadian pacemaker in the mammalian brain. It has been showed that PER2 can positively stimulate activity of the Bmal1-Npas2 transcription complex and, in turn, Npas2 transcriptionally regulates delta-aminolevulinate synthase. It is involved in a negative-feedback loop that attenuates estrogen stimulation and links the circadian cycle to estrogen receptor signaling. The rhythmic levels of PER2 are critical for circadian oscillations in cells and intact organisms. The protein also functions in tumor suppression by regulating DNA damage-responsive pathways