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RDH10
Retinol dehydrogenase 10 is an enzyme that in humans is encoded by the ''RDH10'' gene on chromosome 8. Function RDH10 is a membrane-bound NAD+-dependent retinol dehydrogenase which belongs to the superfamily of short-chain dehydrogenases. RDH10 catalyzes the first oxidative step in retinoic acid biosynthesis: :all-''trans''-retinol+ NAD+ \rightleftharpoons all-''trans''-retinal + NADH + H+ Due to its preference for NAD+ rather than NADP+ as a cofactor, RDH10 functions near-exclusively in the oxidative direction under physiological conditions to increase levels of retinal and retinoic acid. RDH10 has also been shown to act on 11-''cis''-retinol via interactions with CRALBP and RPE65. RDH10 plays an essential role in organ, limb, and craniofacial development during embryogenesis. Clinical significance RDH10 loss of function mutations in mice are embryonically lethal. Despite its similarity to other retinol dehydrogenases, RDH10 is not associated with any known human reti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retinol Dehydrogenase
In enzymology, a retinol dehydrogenase (RDH) () is an enzyme that catalysis, catalyzes the chemical reaction :retinol + NAD+ \rightleftharpoons retinal + NADH + H+ Sometimes, in addition to or along with nicotinamide adenine dinucleotide, NAD+, Nicotinamide adenine dinucleotide phosphate, NADP+ can act as a preferred cofactor in the reaction as well. The substrate of the enzyme can be all-''trans''- or -''cis''- retinol. Some 20 enzymes with RDH activity had been found and studied by 2006. Thus, the two substrate (biochemistry), substrates of this enzyme are retinol and nicotinamide adenine dinucleotide, NAD+, whereas its 3 product (chemistry), products are retinal, nicotinamide adenine dinucleotide, NADH (or NADPH in the case where Nicotinamide adenine dinucleotide phosphate, NADP+ is a cofactor), and hydrogen ion, H+. This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with NAD+ or NADP+ as acceptor. The List of enzymes, sy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Short-chain Dehydrogenase
The short-chain dehydrogenases/reductases family (SDR) is a very large family of enzymes, most of which are known to be NAD- or NADP-dependent oxidoreductases. As the first member of this family to be characterised was Drosophila alcohol dehydrogenase, this family used to be called 'insect-type', or 'short-chain' alcohol dehydrogenases. Most members of this family are proteins of about 250 to 300 amino acid residues. Most dehydrogenases possess at least 2 domains, the first binding the coenzyme, often NAD, and the second binding the substrate. This latter domain determines the substrate specificity and contains amino acids involved in catalysis. Little sequence similarity has been found in the coenzyme binding domain although there is a large degree of structural similarity, and it has therefore been suggested that the structure of dehydrogenases has arisen through gene fusion of a common ancestral coenzyme nucleotide sequence with various substrate specific domains. Subfamilies * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme
An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecules known as product (chemistry), products. Almost all metabolism, metabolic processes in the cell (biology), 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, 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 include Ribozyme, catalytic RNA molecules, also called ribozymes. They are sometimes descr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene
In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protein-coding genes and non-coding genes. During gene expression (the synthesis of Gene product, RNA or protein from a gene), DNA is first transcription (biology), copied into RNA. RNA can be non-coding RNA, directly functional or be the intermediate protein biosynthesis, template for the synthesis of a protein. The transmission of genes to an organism's offspring, is the basis of the inheritance of phenotypic traits from one generation to the next. These genes make up different DNA sequences, together called a genotype, that is specific to every given individual, within the gene pool of the population (biology), population of a given species. The genotype, along with environmental and developmental factors, ultimately determines the phenotype ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromosome 8
Chromosome 8 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 8 spans about 146 million base pairs (the building material of DNA) and represents between 4.5 and 5.0% of the total DNA in cells. About 8% of its genes are involved in brain development and function, and about 16% are involved in cancer. A unique feature of 8p is a region of about 15 megabases that appears to have a high mutation rate. This region shows a significant divergence between human and chimpanzee, suggesting that its high mutation rates have contributed to the evolution of the human brain. __TOC__ Genes Number of genes The following are some of the gene count estimates of human chromosome 8. Because researchers use different approaches to genome annotation their predictions of the number of genes on each chromosome varies (for technical details, see gene prediction). Among various projects, the collaborative consensus coding sequence project ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nicotinamide Adenine Dinucleotide
Nicotinamide adenine dinucleotide (NAD) is a Cofactor (biochemistry), coenzyme central to metabolism. Found in all living cell (biology), 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 Redox, oxidized and reduced form, abbreviated as NAD and NADH (H for hydrogen), respectively. In cellular metabolism, NAD is involved in redox reactions, carrying electrons from one reaction to another, so it is found in two forms: NAD is an oxidizing agent, accepting electrons from other molecules and becoming reduced; with H+, this reaction forms NADH, which can be used as a reducing agent to donate electrons. These electron transfer reactions are the main function of NAD. It is also used in other cellular processes, most notably as a substrate (biochemistry), substrate of enzymes in adding or removing chemical groups to or fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retinoic Acid
Retinoic acid (simplified nomenclature for all-''trans''-retinoic acid) is a metabolite of vitamin A1 (all-''trans''-retinol) that is required for embryonic development, male fertility, regulation of bone growth and immune function. All-''trans''-retinoic acid is required for chordate animal development, which includes all higher animals from fish to humans. During early embryonic development, all-''trans''-retinoic acid generated in a specific region of the embryo helps determine position along the embryonic anterior/posterior axis by serving as an intercellular signaling molecule that guides development of the posterior portion of the embryo. It acts through Hox genes, which ultimately control anterior/posterior patterning in early developmental stages. In adult tissues, the activity of endogenous retinoic acid appears limited to immune function and male fertility. All-''trans''-retinoic acid is the major occurring retinoic acid, while isomers like 13-''cis''- and 9-''cis''-r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retinaldehyde-binding Protein 1
Retinaldehyde-binding protein 1 (RLBP1) also known as cellular retinaldehyde-binding protein (CRALBP) is a 36-kD water-soluble protein that in humans is encoded by the ''RLBP1'' gene. Discovery Cellular retinol binding protein (CRBP) was first discovered in 1973 from lung tissues by Bashor et al. There have been three cellular retinol binding protein categories discovered; Cellular retinol-binding protein, cellular retinoic acid-binding protein and cellular retinaldehyde-binding protein(CRALBP). CRALBP was first discovered in 1977, after it was purified from retina and retinal pigment epithelial cells. Function The cellular retinaldehyde-binding protein transports 11-cis-retinal (also known as 11-cis-retinaldehyde) as its physiological ligands. It plays a critical role as an 11-cis-retinal acceptor which facilitates the enzymatic isomerization of all 11-trans-retinal to 11-cis-retinal, in the isomerization of the rod and cones of the visual cycle. Tissue distribution CR ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RPE65
Retinal pigment epithelium-specific 65 kDa protein (also known as RPE65) is a retinoid isomerohydrolase enzyme of the vertebrate visual cycle. RPE65 is expressed in the retinal pigment epithelium (RPE, a layer of epithelial cells that nourish the photoreceptor cells) and is responsible for the conversion of all-trans-Retinoids, retinyl esters to 11-cis-retinol during phototransduction. 11-cis-retinol is then used in visual pigment regeneration in photoreceptor cells. RPE65 belongs to the carotenoid oxygenase family of enzymes. Function RPE65 is a critical enzyme in the vertebrate Visual phototransduction, visual cycle found in the retinal pigmented epithelium. It is also found in Rod cell, rods and cones. The photoisomerization of 11-cis-retinal to all-trans-retinal initiates the Visual phototransduction, phototransduction pathway through which the brain detects light. All-trans-retinol is not Photochemistry, photoactive and therefore must be reconverted to 11-cis-retinal before ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Embryo
An embryo ( ) is the initial stage of development for a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male sperm cell. The resulting fusion of these two cells produces a single-celled zygote that undergoes many cell divisions that produce cells known as blastomeres. The blastomeres (4-cell stage) are arranged as a solid ball that when reaching a certain size, called a morula, (16-cell stage) takes in fluid to create a cavity called a blastocoel. The structure is then termed a blastula, or a blastocyst in mammals. The mammalian blastocyst hatches before implantating into the endometrial lining of the womb. Once implanted the embryo will continue its development through the next stages of gastrulation, neurulation, and organogenesis. Gastrulation is the formation of the three germ layers that will form all of the different parts of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RDH5
11-cis retinol dehydrogenase is an enzyme that in humans is encoded by the ''RDH5'' gene In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei .... References Further reading * * * * * * * * * * * * * * * * * * {{gene-12-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
White Dot Syndromes
White dot syndromes are inflammatory diseases characterized by the presence of white dots on the fundus, the interior surface of the eye. Tewari A, Elliot D. White Dot Syndromes. 2007. Emedicine from WebMD. The majority of individuals affected with white dot syndromes are younger than fifty years of age. Some symptoms include blurred vision and visual field loss.Quillen DA, Davis JB, Gottlieb JL, Blodi BA, Callanan DG, Chang TS, et al. The white dot syndromes. American Journal of Ophthalmology. 2004;137(3):538-50. There are many theories for the etiology of white dot syndromes including infectious, viral, genetics and autoimmune. Classically recognized white dot syndromes include:Forrester JV, IOIS, Okada AA, BenEzra D. Posterior segment intraocular inflammation: guidelines. 1998:184. * [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
