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PER2
PER2 is a protein in mammals encoded by the ''PER2'' gene. ''PER2'' is noted for its major role in circadian rhythms. Discovery The ''per ''gene'' ''was first discovered using forward genetics in ''Drosophila melanogaster, Drosophilla melanogaster'' in 1971. Mammal, Mammalian Per2 was discovered by in 1997 through a search for homologous cDNA sequences to PER1. It is more similar to Drosophila ''Period (gene), per'' than its Sequence homology, paralogs. Later experiments in also identified ''Per2 ''in humans. Function ''PER2'' is a member of the Period family of genes and is expressed in a circadian pattern in the suprachiasmatic nucleus, the primary circadian pacemaker in the mammalian brain. Genes in this family encode components of the circadian rhythm, circadian clock, which regulates the daily rhythms of locomotor activity, metabolism, and behavior. Circadian expression of these genes and their encoded proteins in the suprachiasmatic nucleus. Human PER2 is involved in h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Advanced Sleep Phase Disorder
Advanced Sleep Phase Disorder (ASPD), also known as the advanced sleep-phase type (ASPT) of circadian rhythm sleep disorder, is a condition that is characterized by a recurrent pattern of early evening (e.g. 7-9 PM) sleepiness and very early morning awakening (e.g. 2-4 AM). This sleep phase advancement can interfere with daily social and work schedules, and results in shortened sleep duration and excessive daytime sleepiness. The timing of sleep and melatonin levels are regulated by the body's central circadian clock, which is located in the suprachiasmatic nucleus in the hypothalamus. Symptoms Individuals with ASPD report being unable to stay awake until conventional bedtime, falling asleep early in the evening, and being unable to stay asleep until their desired waking time, experiencing early morning insomnia. When someone has advanced sleep phase disorder their melatonin levels and core body temperature cycle hours earlier than an average person. These symptoms must be presen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Period (gene)
Period (per) is a gene located on the X chromosome of ''Drosophila melanogaster''. Oscillations in levels of both ''per'' transcript and its corresponding protein PER have a period of approximately 24 hours and together play a central role in the molecular mechanism of the ''Drosophila'' biological clock driving circadian rhythms in eclosion and locomotor activity. Mutations in the per gene can shorten (''perS''), lengthen (''perL''), and even abolish (''per0'') the period of the circadian rhythm. Discovery The period gene and three mutants (''perS'', ''perL'', and ''per0'') were isolated in an EMS mutagenesis screen by Ronald Konopka and Seymour Benzer in 1971. The ''perS'', ''perL'', and ''per0'' mutations were found to not complement each other, so it was concluded that the three phenotypes were due to mutations in the same gene. The discovery of mutants that altered the period of circadian rhythms in eclosion and locomotor activity (''perS'' and ''perL'') indicated the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PER3
The PER3 gene encodes the period circadian protein homolog 3 protein in humans. PER3 is a paralog to the PER1 and PER2 genes. It is a circadian gene associate with delayed sleep phase syndrome in humans. History The Per3 gene was independently cloned by two research groups (Kobe University School of Medicine and the Harvard Medical School) who both published their discovery in June 1998. The mammalian Per3 was discovered by searching for homologous cDNA sequences to Per2. The amino acid sequence of the mouse PERIOD3 protein (mPER3) is between 37-56% similar to the other two PER proteins. Function This gene is a member of the Period family of genes. It is expressed in a circadian pattern in the suprachiasmatic nucleus (SCN), the primary circadian pacemaker in the mammalian brain. Genes in this family encode components of the circadian rhythms of locomotor activity, metabolism, and behavior. Circadian expression in the SCN continues in constant darkness, and a shift in the ligh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PER1
The PER1 gene encodes the period circadian protein homolog 1 protein in humans. Function The PER1 protein is important to the maintenance of circadian rhythms in cells, and may also play a role in the development of cancer. This gene is a member of the period family of genes. It is expressed with a daily oscillating circadian rhythm, or an oscillation that cycles with a period of approximately 24 hours. PER1 is most notably expressed in the region of the brain called the suprachiasmatic nucleus (SCN), which is the primary circadian pacemaker in the mammalian brain. PER1 is also expressed throughout mammalian peripheral tissues. Genes in this family encode components of the circadian rhythms of locomotor activity, metabolism, and behavior. Circadian expression of PER1 in the suprachiasmatic nucleus will free-run in constant darkness, meaning that the 24-hour period of the cycle will persist without the aid of external light cues. Subsequently, a shift in the light/dark cycle evo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Familial Sleep Traits
Familial sleep traits are heritable variations in sleep patterns, resulting in abnormal sleep-wake times and/or abnormal sleep length. Circadian rhythms are coordinated physiological and biological changes that oscillate on an approximately 24-hour cycle. Disruptions to these rhythms in humans may affect the duration, onset, and/or quality of sleep during this cycle, resulting in familial sleep traits. These traits are not necessarily syndromes because they do not always cause distress among individuals. Instead of being disorders, familial sleep traits are variations in an individual's biological tendencies of sleep-wake times, and are only considered syndromes if affected individuals complain about life interference, in which case they may fall under the category of Circadian Rhythm Sleep Disorders (CRSD) that affect sleep timing and circadian rhythms. Some of these circadian disorders include Advanced Sleep Phase Disorder (ASPD) and Delayed Sleep Phase Disorder (DSPD). Familial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Casein Kinase 1
The Casein kinase 1 family () of protein kinases are serine/threonine-selective enzymes that function as regulators of signal transduction pathways in most eukaryotic cell types. CK1 isoforms are involved in Wnt signaling, circadian rhythms, nucleo-cytoplasmic shuttling of transcription factors, DNA repair, and DNA transcription. Discovery By the early 1950s it was known from metabolic labeling studies using radioactive phosphate that phosphate groups attached to phosphoproteins inside cells can sometimes undergo rapid exchange of new phosphate for old. In order to perform experiments that would allow isolation and characterization of the enzymes involved in attaching and removing phosphate from proteins, there was a need for convenient Substrate (biochemistry), substrates for protein kinases and phosphatase, protein phosphatases. Casein has been used as a substrate since the earliest days of research on protein phosphorylation. By the late 1960s, CAMP-dependent protein kinase, cycl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circadian
A circadian rhythm (), or circadian cycle, is a natural, internal process that regulates the sleep–wake cycle and repeats roughly every 24 hours. It can refer to any process that originates within an organism (i.e., endogenous) and responds to the environment ( entrained by the environment). These 24-hour rhythms are driven by a circadian clock, and they have been widely observed in animals, plants, fungi and cyanobacteria. The term ''circadian'' comes from the Latin ''circa'', meaning "approximately", and ''dies'', meaning "day". Processes with 24-hour cycles are more generally called diurnal rhythms; diurnal rhythms should not be called circadian rhythms unless they can be confirmed as endogenous, and not environmental. Although circadian rhythms are endogenous, they are adjusted to the local environment by external cues called zeitgebers (German for "time givers"), which include light, temperature and redox cycles. In clinical settings, an abnormal circadian rhythm in humans ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circadian Rhythm
A circadian rhythm (), or circadian cycle, is a natural, internal process that regulates the sleep–wake cycle and repeats roughly every 24 hours. It can refer to any process that originates within an organism (i.e., Endogeny (biology), endogenous) and responds to the environment (Entrainment (chronobiology), entrained by the environment). These 24-hour rhythms are driven by a circadian clock, and they have been widely observed in animals, plants, fungi and cyanobacteria. The term ''circadian'' comes from the Latin ''wikt:circa#Latin, circa'', meaning "approximately", and ''dies'', meaning "day". Processes with 24-hour cycles are more generally called diurnal rhythms; diurnal rhythms should not be called circadian rhythms unless they can be confirmed as endogenous, and not environmental. Although circadian rhythms are endogenous, they are adjusted to the local environment by external cues called zeitgebers (German for "time givers"), which include light, temperature and redox cy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BMAL1
Aryl hydrocarbon receptor nuclear translocator-like protein 1 (ARNTL) or brain and muscle ARNT-Like 1 (BMAL1) is a protein that in humans is encoded by the gene on chromosome 11, region p15.3. It's also known as ''BMAL1'', ''MOP3'', and, less commonly, ''bHLHe5'', ''BMAL'', ''BMAL1C'', ''JAP3'', ''PASD3'', and ''TIC''. ''ARNTL'' encodes a transcription factor with a basic helix-loop-helix (bHLH) and two PAS domains. The human ''ARNTL'' gene has a predicted 24 exons, located on the p15 band of the 11th chromosome. The ARNTL protein is 626 amino acids long and plays a key role as one of the positive elements in the mammalian auto-regulatory transcription-translation negative feedback loop (TTFL), which is responsible for generating molecular circadian rhythms. Research has revealed that ''ARNTL'' is the only clock gene without which the circadian clock fails to function in humans. ''ARNTL'' has also been identified as a candidate gene for susceptibility to hypertension, diabetes, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Suprachiasmatic Nucleus
The suprachiasmatic nucleus or nuclei (SCN) is a tiny region of the brain in the hypothalamus, situated directly above the optic chiasm. It is responsible for controlling circadian rhythms. The neuronal and hormonal activities it generates regulate many different body functions in a 24-hour cycle. The mouse SCN contains approximately 20,000 neurons. The SCN interacts with many other regions of the brain. It contains several cell types and several different peptides (including vasopressin and vasoactive intestinal peptide) and neurotransmitters. Neuroanatomy The SCN is situated in the anterior part of the hypothalamus immediately dorsal, or ''superior'' (hence supra) to the optic chiasm (CHO) bilateral to (on either side of) the third ventricle. The nucleus can be divided into ventrolateral and dorsolateral portions, also known as the core and shell, respectively. These regions differ in their expression of the clock genes, the core expresses them in response to stimuli whereas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, providing structure to cells and organisms, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific 3D structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called peptides. The individual amino acid residues are bonded together by peptide bonds and adjacent amino acid residues. The sequence of amino acid residue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclin D1
Cyclin D1 is a protein that in humans is encoded by the ''CCND1'' gene. Gene expression The CCND1 gene encodes the cyclin D1 protein. The human CCND1 gene is located on the long arm of chromosome 11 (band 11q13). It is 13,388 base pairs long, and translates into 295 amino acids. Cyclin D1 is expressed in all adult human tissues with the exception of cells derived from bone marrow stem cell lines (both lymphoid and myeloid). Protein structure Cyclin D1 is composed of the following protein domains and motifs: * retinoblastoma protein (pRb) binding motif; * cyclin box domain for cyclin-dependent kinase (CDK) binding and CDK inhibitor binding; * LxxLL binding motif for co-activator recruitment; * PEST sequence that may mark the protein for degradation; * threonine residue (threonine 286) that controls nuclear export and protein stability. Function The protein encoded by this gene belongs to the highly conserved cyclin family, whose members are characterized by a dramatic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
