Nucleotides are organic molecules composed of a nitrogenous base, a pentose sugar and a phosphate. They serve as monomeric units of the nucleic acid polymers – deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), both of which are essential biomolecules within all life-forms on Earth. Nucleotides are obtained in the diet and are also synthesized from common nutrients by the liver.
Nicotinamide adenine dinucleotide (NAD) is a coenzyme central to metabolism. Found in all living cells, NAD is called a dinucleotide because it consists of two nucleotides joined through their phosphate groups. One nucleotide contains an adenine nucleobase and the other, nicotinamide. NAD exists in two forms: an oxidized and reduced form, abbreviated as NAD+ and NADH (H for hydrogen), respectively.
Dale Sanders, FRS was Director of the John Innes Centre, an institute for research in plant sciences and microbiology in Norwich, England.
Ryanodine receptors form a class of intracellular calcium channels in various forms of excitable animal tissue like muscles and neurons. There are three major isoforms of the ryanodine receptor, which are found in different tissues and participate in different signaling pathways involving calcium release from intracellular organelles. The RYR2 ryanodine receptor isoform is the major cellular mediator of calcium-induced calcium release (CICR) in animal cells.
Calcium signaling is the use of calcium ions (Ca2+) to communicate and drive intracellular processes often as a step in signal transduction. Ca2+ is important for cellular signalling, for once it enters the cytosol of the cytoplasm it exerts allosteric regulatory effects on many enzymes and proteins. Ca2+ can act in signal transduction resulting from activation of ion channels or as a second messenger caused by indirect signal transduction pathways such as G protein-coupled receptors.
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.
Diphtheria toxin is an exotoxin secreted mainly by Corynebacterium diphtheriae but also by Corynebacterium ulcerans and Corynebacterium pseudotuberculosis. the pathogenic bacterium that causes diphtheria. The toxin gene is encoded by a prophage called corynephage β. The toxin causes the disease in humans by gaining entry into the cell cytoplasm and inhibiting protein synthesis.
Sir Michael John Berridge was a British physiologist and biochemist.
Two-pore channels (TPCs) are eukaryotic intracellular voltage-gated and ligand gated cation selective ion channels. There are two known paralogs in the human genome, TPC1s and TPC2s. In humans, TPC1s are sodium selective and TPC2s conduct sodium ions, calcium ions and possibly hydrogen ions. Plant TPC1s are non-selective channels. Expression of TPCs are found in both plant vacuoles and animal acidic organelles. These organelles consist of endosomes and lysosomes. TPCs are formed from two transmembrane non-equivalent tandem Shaker-like, pore-forming subunits, dimerized to form quasi-tetramers. Quasi-tetramers appear very similar to tetramers, but are not quite the same. Some key roles of TPCs include calcium dependent responses in muscle contraction(s), hormone secretion, fertilization, and differentiation. Disorders linked to TPCs include membrane trafficking, Parkinson's disease, Ebola, and fatty liver.
The inorganic dye ammoniated ruthenium oxychloride, also known as ruthenium red, is used in histology to stain aldehyde fixed mucopolysaccharides.
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.
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.
Adenosine diphosphate ribose (ADPR) is an ester molecule formed into chains by the enzyme poly ADP ribose polymerase. ADPR is created from cyclic ADP-ribose (cADPR) by the CD38 enzyme using nicotinamide adenine dinucleotide (NAD+) as a cofactor.
In enzymology, a NAD+ glycohydrolase (EC 3.2.2.5) is an enzyme that catalyzes the chemical reaction
Two pore segment channel 1 (TPC1) is a human protein encoded by the TPCN1 gene. The protein encoded by this gene is an ion channel. In contrast to other calcium and sodium channels which have four homologous domains, each containing 6 transmembrane segments, TPCN1 only contains two domains.
Two pore segment channel 2 (TPC2) is a protein which in humans is encoded by the TPCN2 gene. TPC2 is an ion channel, however, in contrast to other calcium and sodium channels which have four homologous domains, each containing 6 transmembrane segments, TPCN1 only contains two domain.
Annette Catherine Dolphin is a Professor of Pharmacology in the Department of Neuroscience, Physiology and Pharmacology at University College London (UCL).
Barry Victor Lloyd Potter MAE FMedSci is a British chemist, who is Professor of Medicinal & Biological Chemistry at the University of Oxford, Wellcome Trust Senior Investigator and a Fellow of University College, Oxford.
Anant B. Parekh is professor of Physiology at the University of Oxford and a Fellow of Merton College, Oxford.
Trans-NED-19 is a drug which acts as a potent and selective antagonist of the endogenous calcium channel opener nicotinic acid adenine dinucleotide phosphate (NAADP), thereby reducing the normal NAADP-mediated calcium flux without blocking calcium channels directly. It is used in research into the functions of NAADP signalling inside many different cell types.
