High impact information on PER3

• Circadian clock in culture: N-acetyltransferase activity of chick pineal glands oscillates in vitro [1].
• These results demonstrate that a circadian clock from a homeothermic vertebrate is temperature compensated, yet temperature cycles can entrain the circadian melatonin rhythm [2].
• Negative control of circadian clock regulator E4BP4 by casein kinase Iepsilon-mediated phosphorylation [3].
• p38 mitogen-activated protein kinase regulates oscillation of chick pineal circadian clock [4].
• The circadian clock is an autonomous biological clock that is entrainable to environmental 24-h cycles by receiving time cues such as light [5].

Biological context of PER3

• Thus GR196429 is a potent and selective agonist at high-affinity melatonin receptors, which modulates circadian rhythms in an in vitro model of the circadian clock and which readily penetrates the CNS [6].
• Our results show that: (1) the circadian clock and/or the intracellular signal transduction system connecting the clock to MT synthesizing apparatus develop between the embryonic days 16-18 (E16-18), even in vitro [7].
• Ontogeny of circadian clock gene expression in the pineal and the suprachiasmatic nucleus of chick embryo [8].
• Using dynamic in vitro bioassays, we showed the following: (1) The circadian clock and/or the intracellular signal transduction pathways connecting the clock to the MT synthesizing apparatus appear between days 16 and 18 (E16-18) of embryonic development [9].
• Light is a major environmental signal for entrainment of the circadian clock, but little is known about the intracellular phototransduction pathway triggered by light activation of the photoreceptive molecule(s) responsible for the phase shift of the clock in vertebrates [10].

Anatomical context of PER3

• In slices of rat brain suprachiasmatic nucleus, perfusion (1 h) with GR196429 at zeitgeber time 10 phase advanced the circadian peak in neuronal activity measured on the following day, with a maximum phase advance of 2.7 +/- 0.3 h at 10 pM and an EC50 of 0.6 pM, results that indicated a melatonin-like action on the phase of the circadian clock [6].
• Synthesis of retinal ganglion cell phospholipids is under control of an endogenous circadian clock: daily variations in phospholipid-synthesizing enzyme activities [11].
• Many tissues in non-mammalian vertebrates contain both photoreceptors and circadian clock systems [12].

Associations of PER3 with chemical compounds

• Tryptophan hydroxylase mRNA levels are regulated by the circadian clock, temperature, and cAMP in chick pineal cells [13].
• Vertebrate cryptochrome homologs (CRYs) are negative regulators for the transcription/translation-based autoregulatory feedback loop of the circadian clock [14].

Regulatory relationships of PER3

• The rhythm in TPH mRNA also persists in constant darkness, suggesting that TPH mRNA synthesis and/or turnover is regulated by an endogenous circadian clock in cultured chick pineal cells [15].
• These rhythms appear to reflect circadian clock control of AA-NAT mRNA abundance and independent effects of light and darkness on both mRNA levels and enzyme activity [16].

Other interactions of PER3

• Iodopsin is a circadian-regulated, photoreceptor-specific gene expressed in chicken retina, and Clock is a transcription factor that has been shown to play a role in the circadian clock mechanism in mouse and Drosophila [17].
• Development of light-dark regulation of AANAT activity appears to precede the circadian clock-control of enzyme activity [18].
• Clearly, the expression of pinopsin gene is controlled by a light signal, independent of the circadian clock [19].
• Together, our results demonstrate the existence of a G11-mediated opsin-signaling pathway contributing to the photic entrainment of the circadian clock [10].

Analytical, diagnostic and therapeutic context of PER3

• Circadian clock in cell culture: I. Oscillation of melatonin release from dissociated chick pineal cells in flow-through microcarrier culture [20].

References