The objective of the current study was to investigate the expression pattern and clinicopathological significance of Period1 (Per1), Period2 (Per2) and Period3 (Per3) in patients with non-small cell lung cancer (NSCLC). In 130 archived NSCLC tissues, the positive rate of Per1 (86/130, 66.2%), Per2 (77/130, 59.2%) and Per3 (82/130, 63.1%) were reduced in human lung cancer samples compared with a...

In mammals, the molecular circadian clockwork is comprised of interlocked transcriptional-translational feedback loops (TTLs). Three Period (Per1-3) and 2 Dec (Dec1/2) genes interact in regulating the activity of the transcriptional activators CLOCK/NPAS2 and BMAL1. While deletion of Per1 and Per2 in mice results in behavioral arrhythmicity, Dec deletion has less dramatic effects on activity rh...

The mammalian circadian pacemaker in the suprachiasmatic nuclei (SCN) controls daily rhythms of behavior and physiology. Lesions of the SCN cause arrhythmicity of locomotor activity, and transplants of fetal SCN tissue restore rhythmic behavior that is consistent with the periodicity of the donor's genotype, suggesting that the SCN determines the period of the circadian behavioral rhythm. While...

The Per1 and Per2 genes are components of the mammalian circadian clock. Mutations in these genes alter phase resetting in response to a nocturnal light pulse, and Per2 mutant mice are known to become arrhythmic in constant darkness. We show that under constant light conditions, Per2 mutant mice exhibit robust activity rhythms as well as body temperature rhythms with a period length that is les...

The circadian clock nucleus of the mammalian brain is composed of thousands of oscillator neurons, each driven by the cell-autonomous action of a defined set of circadian clock genes. A critical question is how these individual oscillators are organized into an internal clock that times behavior and physiology. We examined the neural organization of the suprachiasmatic nucleus (SCN) through tim...

Three mammalian Period (Per) genes, termed Per1, Per2, and Per3, have been identified as structural homologues of the Drosophila circadian clock gene, period (per). The three Per genes are rhythmically expressed in the suprachiasmatic nucleus (SCN), the central circadian pacemaker in mammals. The phases of peak mRNA levels for the three Per genes in the SCN are slightly different. Light sequent...

Clock genes are believed to play a pivotal role in the generation and oscillation of circadian rhythm as a central clock in the hypothalamic suprachiasmatic nucleus in the mammalian brain. In this study, mRNA expression was for the first time demonstrated with clock genes in both cultured murine microglia and microglial cell line BV-2 cells. Exposure to ATP transiently increased Period-1 (Per1)...

Rhythmicity of the rat suprachiasmatic nucleus (SCN), a site of the circadian clock, develops prenatally. A molecular clockwork responsible for the rhythmicity consists of clock genes and their negative and positive transcriptional-translational feedback loops. The aim of the present study was to discover the development of the clockwork during ontogenesis. Daily profiles of Per1, Per2, Cry1, B...

We have characterized a mammalian homolog of the Drosophila period gene and designated it Per2. The PER2 protein shows >40% amino acid identity to the protein of another mammalian per homolog (designated Per1) that was recently cloned and characterized. Both PER1 and PER2 proteins share several regions of homology with the Drosophila PER protein, including the protein dimerization PAS domain. P...

By the effort to identify candidate signaling molecules important for formation of robust circadian rhythms in suprachiasmatic nucleus (SCN), mammalian center, here we characterize role ?2? proteins, synaptic initially identified as an auxiliary subunit voltage dependent calcium channel, rhythm formation. In situ hybridization study demonstrated that type 3 gene (?2?3) was strongly expressed SC...