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SARM1
Sterile alpha and TIR motif containing 1 Is an enzyme that in humans is encoded by the ''SARM1'' gene. It is the most evolutionarily conserved member of the Toll/Interleukin receptor-1 (TIR) family. SARM1's TIR domain has intrinsic NADase enzymatic activity that is highly conserved from archaea, plants, nematode worms, fruit flies, and humans. In mammals, SARM1 is highly expressed in neurons, where it resides in both cell bodies and axons, and can be associated with mitochondria. Function While SARM1 has been studied as a Toll-like receptor adaptor protein in an immune context, its most well-studied function in mammals is as a sensor of metabolic stress and an executioner of neuronal cell body and axon death. Because SARM1 is highly expressed in the nervous system, most studies of SARM1 focus on neuron degeneration, but some SARM1 can be found in other tissues, notably macrophages and T cells. By generating cADPR or NAADP, SARM1 may function as a Ca2+-signaling enzyme sim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CD38
CD38 (cluster of differentiation 38), also known as cyclic ADP ribose hydrolase is a glycoprotein found on the surface of many immune cells (white blood cells), including CD4+, CD8+, B lymphocytes and natural killer cells. CD38 also functions in cell adhesion, signal transduction and calcium signaling. In humans, the CD38 protein is encoded by the CD38 gene which is located on chromosome 4. CD38 is a paralog of CD157, which is also located on chromosome 4 (4p15) in humans. History CD38 was first identified in 1980 as a surface marker (cluster of differentiation) of thymus cell lymphocytes. In 1992 it was additionally described as a surface marker on B cells, monocytes, and natural killer cells (NK cells). About the same time, CD38 was discovered to be not simply a marker of cell types, but an activator of B cells and T cells. In 1992 the enzymatic activity of CD38 was discovered, having the capacity to synthesize the calcium-releasing second messengers cyclic ADP-ribose (cA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vacor
Pyrinuron (Pyriminil, Vacor) is a chemical compound formerly used as a rodenticide. Commercial distribution was voluntarily suspended in 1979 and it is not approved by the Environmental Protection Agency for use in the United States. If it is ingested by humans in high doses, it may selectively destroy insulin-producing beta cells in the pancreas causing type 1 diabetes. The neurodegeneration associated with Vacor is caused by its conversion to Vacor-mononucleotide (VMN) by NAMPT and VMN's subsequent activation of the NADase SARM1 Sterile alpha and TIR motif containing 1 Is an enzyme that in humans is encoded by the ''SARM1'' gene. It is the most evolutionarily conserved member of the Toll/Interleukin receptor-1 (TIR) family. SARM1's TIR domain has intrinsic NADase enzym .... References Rodenticides Ureas 3-Pyridyl compounds Nitrobenzenes {{organic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclic ADP-ribose
Cyclic ADP Ribose, frequently abbreviated as cADPR, is a cyclic adenine nucleotide (like cAMP) with two phosphate groups present on 5' OH of the adenosine (like ADP), further connected to another ribose at the 5' position, which, in turn, closes the cycle by glycosidic bonding to the nitrogen 1 (N1) of the same adenine base (whose position N9 has the glycosidic bond to the other ribose). The N1-glycosidic bond to adenine is what distinguishes cADPR from ADP-ribose (ADPR), the non-cyclic analog. cADPR is produced from nicotinamide adenine dinucleotide (NAD+) by ADP-ribosyl cyclases ( EC 3.2.2.5) as part of a second messenger system. Function cADPR is a cellular messenger for calcium signaling. It stimulates calcium-induced calcium release at lower cytosolic concentrations of Ca2+. The primary target of cADPR is the endoplasmic reticulum Ca2+ uptake mechanism. cADPR mobilizes Ca2+ from the endoplasmic reticulum by activation of ryanodine receptors, a critical step in muscle contracti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nicotinic Acid Adenine Dinucleotide Phosphate
Nicotinic acid adenine dinucleotide phosphate, (NAADP), is a Ca2+-mobilizing second messenger synthesised in response to extracellular stimuli. Like its mechanistic cousins, IP3 and cyclic adenosine diphosphoribose (Cyclic ADP-ribose), NAADP binds to and opens Ca2+ channels on intracellular organelles, thereby increasing the intracellular Ca2+ concentration which, in turn, modulates sundry cellular processes (see Calcium signalling). Structurally, it is a dinucleotide that only differs from the house-keeping enzyme cofactor, NADP by a hydroxyl group (replacing the nicotinamide amino group) and yet this minor modification converts it into the most potent Ca2+-mobilizing second messenger yet described. NAADP acts across phyla from plants to humans. Discovery In their landmark 1987 paper, Hon Cheung Lee and colleagues discovered not one but two Ca2+-mobilizing second messengers, cADPR and NAADP from the effects of nucleotides on Ca2+ release in sea urchin egg homogenates. It turns ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. Almost all metabolic processes in the cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps. The study of enzymes is called ''enzymology'' and the field of pseudoenzyme analysis recognizes that during evolution, some enzymes have lost the ability to carry out biological catalysis, which is often reflected in their amino acid sequences and unusual 'pseudocatalytic' properties. Enzymes are known to catalyze more than 5,000 biochemical reaction types. Other biocatalysts are catalytic RNA molecules, called ribozymes. Enzymes' specificity comes from their unique three-dimensional structures. Like all catalysts, enzymes increase the reaction ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Traumatic Brain Injury
A traumatic brain injury (TBI), also known as an intracranial injury, is an injury to the brain caused by an external force. TBI can be classified based on severity (ranging from mild traumatic brain injury TBI/concussionto severe traumatic brain injury), mechanism ( closed or penetrating head injury), or other features (e.g., occurring in a specific location or over a widespread area). Head injury is a broader category that may involve damage to other structures such as the scalp and skull. TBI can result in physical, cognitive, social, emotional and behavioral symptoms, and outcomes can range from complete recovery to permanent disability or death. Causes include falls, vehicle collisions and violence. Brain trauma occurs as a consequence of a sudden acceleration or deceleration within the cranium or by a complex combination of both movement and sudden impact. In addition to the damage caused at the moment of injury, a variety of events following the injury may result in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mitogen-activated Protein Kinase
A mitogen-activated protein kinase (MAPK or MAP kinase) is a type of protein kinase that is specific to the amino acids serine and threonine (i.e., a serine/threonine-specific protein kinase). MAPKs are involved in directing cellular responses to a diverse array of stimuli, such as mitogens, osmotic stress, heat shock and proinflammatory cytokines. They regulate cell functions including proliferation, gene expression, differentiation, mitosis, cell survival, and apoptosis. MAP kinases are found in eukaryotes only, but they are fairly diverse and encountered in all animals, fungi and plants, and even in an array of unicellular eukaryotes. MAPKs belong to the CMGC (CDK/MAPK/GSK3/CLK) kinase group. The closest relatives of MAPKs are the cyclin-dependent kinases (CDKs). Discovery The first mitogen-activated protein kinase to be discovered was ERK1 (MAPK3) in mammals. Since ERK1 and its close relative ERK2 (MAPK1) are both involved in growth factor signaling, the family was term ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nicotinamide Phosphoribosyltransferase
Nicotinamide phosphoribosyltransferase (NAmPRTase or NAMPT), formerly known as pre-B-cell colony-enhancing factor 1 (PBEF1) or visfatin for its extracellular form (eNAMPT), is an enzyme that in humans is encoded by the ''NAMPT'' gene. The intracellular form of this protein (iNAMPT) is the rate-limiting enzyme in the nicotinamide adenine dinucleotide (NAD+) salvage pathway that converts nicotinamide to nicotinamide mononucleotide (NMN) which is responsible for most of the NAD+ formation in mammals. iNAMPT can also catalyze the synthesis of NMN from phosphoribosyl pyrophosphate (PRPP) when ATP is present. eNAMPT has been reported to be a cytokine (PBEF) that activates TLR4, that promotes B cell maturation, and that inhibits neutrophil apoptosis. Reaction iNAMPT catalyzes the following chemical reaction: :nicotinamide + 5-phosphoribosyl-1-pyrophosphate (PRPP) \rightleftharpoons nicotinamide mononucleotide (NMN) + pyrophosphate (PPi) Thus, the two substrates of this enzyme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurotoxin
Neurotoxins are toxins that are destructive to nerve tissue (causing neurotoxicity). Neurotoxins are an extensive class of exogenous chemical neurological insultsSpencer 2000 that can adversely affect function in both developing and mature nervous tissue.Olney 2002 The term can also be used to classify endogenous compounds, which, when abnormally contacted, can prove neurologically toxic. Though neurotoxins are often neurologically destructive, their ability to specifically target neural components is important in the study of nervous systems. Common examples of neurotoxins include lead, ethanol (drinking alcohol), glutamate,Choi 1987 nitric oxide, botulinum toxin (e.g. Botox), tetanus toxin,Simpson 1986 and tetrodotoxin. Some substances such as nitric oxide and glutamate are in fact essential for proper function of the body and only exert neurotoxic effects at excessive concentrations. Neurotoxins inhibit neuron control over ion concentrations across the cell membrane, or com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nicotinamide Mononucleotide
Niacinamide or Nicotinamide (NAM) is a form of vitamin B3 found in food and used as a dietary supplement and medication. As a supplement, it is used by mouth to prevent and treat pellagra (niacin deficiency). While nicotinic acid (niacin) may be used for this purpose, niacinamide has the benefit of not causing skin flushing. As a cream, it is used to treat acne. It is a water-soluble vitamin. Niacinamide is the supplement name while Nicotinamide (NAM) is the scientific name. Side effects are minimal. At high doses liver problems may occur. Normal amounts are safe for use during pregnancy. Niacinamide is in the vitamin B family of medications, specifically the vitamin B3 complex. It is an amide of nicotinic acid. Foods that contain niacinamide include yeast, meat, milk, and green vegetables. Niacinamide was discovered between 1935 and 1937. It is on the World Health Organization's List of Essential Medicines. Niacinamide is available as a generic medication and over the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orthosteric Site
In biochemistry, allosteric regulation (or allosteric control) is the regulation of an enzyme by binding an effector molecule at a site other than the enzyme's active site. The site to which the effector binds is termed the ''allosteric site'' or ''regulatory site''. Allosteric sites allow effectors to bind to the protein, often resulting in a conformational change and/or a change in protein dynamics. Effectors that enhance the protein's activity are referred to as ''allosteric activators'', whereas those that decrease the protein's activity are called ''allosteric inhibitors''. Allosteric regulations are a natural example of control loops, such as feedback from downstream products or feedforward from upstream substrates. Long-range allostery is especially important in cell signaling. Allosteric regulation is also particularly important in the cell's ability to adjust enzyme activity. The term ''allostery'' comes from the Ancient Greek ''allos'' (), "other", and ''stere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nicotinamide
Niacinamide or Nicotinamide (NAM) is a form of vitamin B3 found in food and used as a dietary supplement and medication. As a supplement, it is used by mouth to prevent and treat pellagra (niacin deficiency). While nicotinic acid (niacin) may be used for this purpose, niacinamide has the benefit of not causing skin flushing. As a cream, it is used to treat acne. It is a water-soluble vitamin. Niacinamide is the supplement name while Nicotinamide (NAM) is the scientific name. Side effects are minimal. At high doses liver problems may occur. Normal amounts are safe for use during pregnancy. Niacinamide is in the vitamin B family of medications, specifically the vitamin B3 complex. It is an amide of nicotinic acid. Foods that contain niacinamide include yeast, meat, milk, and green vegetables. Niacinamide was discovered between 1935 and 1937. It is on the World Health Organization's List of Essential Medicines. Niacinamide is available as a generic medication and over the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
