A fluorophore is a fluorescent chemical compound that can re-emit light upon light excitation. Fluorophores typically contain several combined aromatic groups, or planar or cyclic molecules with several π bonds.
Cone cells, or cones, are photoreceptor cells in the retinas of vertebrate eyes including the human eye. They respond differently to light of different wavelengths, and the combination of their responses is responsible for color vision. Cones function best in relatively bright light, called the photopic region, as opposed to rod cells, which work better in dim light, or the scotopic region. Cone cells are densely packed in the fovea centralis, a 0.3 mm diameter rod-free area with very thin, densely packed cones which quickly reduce in number towards the periphery of the retina. Conversely, they are absent from the optic disc, contributing to the blind spot. There are about six to seven million cones in a human eye, with the highest concentration being towards the macula.
In molecular biology, housekeeping genes are typically constitutive genes that are required for the maintenance of basic cellular function, and are expressed in all cells of an organism under normal and patho-physiological conditions. Although some housekeeping genes are expressed at relatively constant rates in most non-pathological situations, the expression of other housekeeping genes may vary depending on experimental conditions.
Melanopsin is a type of photopigment belonging to a larger family of light-sensitive retinal proteins called opsins and encoded by the gene Opn4. In the mammalian retina, there are two additional categories of opsins, both involved in the formation of visual images: rhodopsin and photopsin in the rod and cone photoreceptor cells, respectively.
Drug metabolism is the metabolic breakdown of drugs by living organisms, usually through specialized enzymatic systems. More generally, xenobiotic metabolism is the set of metabolic pathways that modify the chemical structure of xenobiotics, which are compounds foreign to an organism's normal biochemistry, such as any drug or poison. These pathways are a form of biotransformation present in all major groups of organisms and are considered to be of ancient origin. These reactions often act to detoxify poisonous compounds. The study of drug metabolism is called pharmacokinetics.
The ATP-binding cassette transporters are a transport system superfamily that is one of the largest and possibly one of the oldest gene families. It is represented in all extant phyla, from prokaryotes to humans. ABC transporters belong to translocases.
P-glycoprotein 1 also known as multidrug resistance protein 1 (MDR1) or ATP-binding cassette sub-family B member 1 (ABCB1) or cluster of differentiation 243 (CD243) is an important protein of the cell membrane that pumps many foreign substances out of cells. More formally, it is an ATP-dependent efflux pump with broad substrate specificity. It exists in animals, fungi, and bacteria, and it likely evolved as a defense mechanism against harmful substances.
The dopamine transporter is a membrane-spanning protein that pumps the neurotransmitter dopamine out of the synaptic cleft back into cytosol. In the cytosol, other transporters sequester the dopamine into vesicles for storage and later release. Dopamine reuptake via DAT provides the primary mechanism through which dopamine is cleared from synapses, although there may be an exception in the prefrontal cortex, where evidence points to a possibly larger role of the norepinephrine transporter.
Calcein, also known as fluorexon, fluorescein complex, is a fluorescent dye with excitation and emission wavelengths of 495/515 nm, respectively, and has the appearance of orange crystals. Calcein self-quenches at concentrations above 70mM and is commonly used as an indicator of lipid vesicle leakage. It is also used traditionally as a complexometric indicator for titration of calcium ions with EDTA, and for fluorometric determination of calcium.
ATP-binding cassette sub-family C member 4 (ABCC4), also known as the multidrug resistance-associated protein 4 (MRP4) or multi-specific organic anion transporter B (MOAT-B), is a protein that in humans is encoded by the ABCC4 gene.
ATP-binding cassette super-family G member 2 is a protein that in humans is encoded by the ABCG2 gene. ABCG2 has also been designated as CDw338. ABCG2 is a translocation protein used to actively pump drugs and other compounds against their concentration gradient using the bonding and hydrolysis of ATP as the energy source.
Multidrug resistance-associated protein 1 (MRP1) is a protein that in humans is encoded by the ABCC1 gene.
Multidrug resistance-associated protein 2 (MRP2) also called canalicular multispecific organic anion transporter 1 (cMOAT) or ATP-binding cassette sub-family C member 2 (ABCC2) is a protein that in humans is encoded by the ABCC2 gene.
Canalicular multispecific organic anion transporter 2 is a protein that in humans is encoded by the ABCC3 gene.
Multidrug resistance-associated protein 5 is a protein that in humans is encoded by the ABCC5 gene.
The latency-associated nuclear antigen (LANA-1) or latent nuclear antigen is a Kaposi's sarcoma-associated herpesvirus (KSHV) latent protein initially found by Moore and colleagues as a speckled nuclear antigen present in primary effusion lymphoma cells that reacts with antibodies from patients with KS. It is the most immunodominant KSHV protein identified by Western-blotting as 222–234 kDa double bands migrate slower than the predicted molecular weight. LANA has been suspected of playing a crucial role in modulating viral and cellular gene expression. It is commonly used as an antigen in blood tests to detect antibodies in persons that have been exposed to KSHV.
The organic anion transporter 1 (OAT1) also known as solute carrier family 22 member 6 (SLC22A6) is a protein that in humans is encoded by the SLC22A6 gene. It is a member of the organic anion transporter (OAT) family of proteins. OAT1 is a transmembrane protein that is expressed in the brain, the placenta, the eyes, smooth muscles, and the basolateral membrane of proximal tubular cells of the kidneys. It plays a central role in renal organic anion transport. Along with OAT3, OAT1 mediates the uptake of a wide range of relatively small and hydrophilic organic anions from plasma into the cytoplasm of the proximal tubular cells of the kidneys. From there, these substrates are transported into the lumen of the nephrons of the kidneys for excretion. OAT1 homologs have been identified in rats, mice, rabbits, pigs, flounders, and nematodes.
Decynium-22 is a cationic derivative of quinoline, and a potent inhibitor of the plasma membrane monoamine transporter (PMAT), as well as all members of the organic cation transporter (OCT) family in both human and rat cells. However, it has little effect on high affinity monoamine transporters such as the dopamine transporter and norepinephrine transporter.
Piet Borst is emeritus professor of Clinical Biochemistry and Molecular Biology at the University of Amsterdam (UVA), and until 1999 Director of Research and Chairman of the Board of Directors of the Netherlands Cancer Institute and the Antoni van Leeuwenhoekziekenhuis (NKI-AVL). He continued to work at the NKI-AVL as a staff member and group leader until 2016.
Estradiol glucuronide, or estradiol 17β-D-glucuronide, is a conjugated metabolite of estradiol. It is formed from estradiol in the liver by UDP-glucuronyltransferase via attachment of glucuronic acid and is eventually excreted in the urine by the kidneys. It has much higher water solubility than does estradiol. Glucuronides are the most abundant estrogen conjugates.
