Uridine Phosphorylase
Phosphorylases
Uridine Kinase
Pentosyltransferases
Uridine
Uracil
Purine-Nucleoside Phosphorylase
Thymidine Phosphorylase
Floxuridine
Phosphorylase Kinase
Phosphorylase b
Phosphorylase a
Pyrimidine Nucleosides
Glycogen Phosphorylase
Role of multiple CytR binding sites on cooperativity, competition, and induction at the Escherichia coli udp promoter. (1/79)
The CytR repressor fulfills dual roles as both a repressor of transcription from promoters of the Escherichia coli CytR regulon and a co-activator in some circumstances. Transcription is repressed by a three-protein complex (cAMP receptor protein (CRP)-CytR-CRP) that is stabilized by cooperative interactions between CRP and CytR. However, cooperativity also means that CytR can recruit CRP and, by doing so, can act as a co-activator. The central role of cooperativity in regulation is highlighted by the fact that binding of the inducer, cytidine, to CytR is coupled to CytR-CRP cooperativity; this underlies the mechanism for induction. Similar interactions at the different promoters of the CytR regulon coordinate expression of the transport proteins and enzymes required for nucleoside catabolism but also provide differential expression of these genes. A fundamental question in both prokaryotic and eukaryotic gene regulation is how combinatorial mechanisms of this sort regulate differential expression. Recently, we showed that CytR binds specifically to multiple sites in the E. coli deoP promoter, thereby providing competition for CRP binding to CRP operator site 1 (CRP1) and CRP2 as well as cooperativity. The effect of the competition at this promoter is to negate the role of CytR in recruiting CRP. Here, we have used quantitative footprint and mobility shift analysis to investigate CRP and CytR binding to the E. coli udp promoter. Here too, we find that CytR both cooperates and competes for CRP binding. However, consistent with both the distribution of CytR recognition motifs in the sequence of the promoter and the regulation of the promoter, the competition is limited to CRP2. When cytidine binds to CytR, the effect on cooperativity is very different at the udp promoter than at the deoP2 promoter. Cooperativity with CRP at CRP1 is nearly eliminated, but the effect on CytR-CRP2 cooperativity is negligible. These results are discussed in relation to the current structural model of CytR in which the core, inducer-binding domain is tethered to the helix-turn-helix, DNA-binding domain via flexible peptide linkers. (+info)Genomic structure, chromosomal mapping, and promoter region analysis of murine uridine phosphorylase gene. (2/79)
Uridine phosphorylase (UPase) plays an important role in the activation of 5-fluorouracil and in the regulation of tissue and plasma concentration of uridine, a potential biochemical modulator of 5-fluorouracil therapy. UPase expression is affected by the c-H-ras oncogene and various cytokines through unknown mechanisms. To understand its expression and regulation, we cloned the murine UPase gene, defined its genomic organization, determined its 5'- and 3'-end flanking sequences, and evaluated the promoter activity. The UPase gene contains nine exons and eight introns, spanning a total of approximately 18.0 kb. Its promoter lacks canonical TATA and CCAAT boxes, although a CAATAAAAA TATA-like box is seen from -41 to -49. Furthermore, IFN regulatory factor 1, c/v-Myb, and p53 binding sites are present in the promoter region, indicating that UPase expression may be directly regulated by cytokines and oncogene products. The 1.2-kb flanking fragment showed promoter activity driving the expression of the luciferase gene in various mammalian cells. A TGGGG repeat sequence is seen in the 3'-end flanking region. This element is considered to be a potential recombination consensus hot spot that may contribute to the encoding of different UPase isoforms present in different tissues, both normal and neoplastic. (+info)Ribose 1-phosphate and inosine activate uracil salvage in rat brain. (3/79)
The purpose of this study was to determine the mechanism by which inosine activates pyrimidine salvage in CNS. The levels of cerebral inosine, hypoxanthine, uridine, uracil, ribose 1-phosphate and inorganic phosphate were determined, to evaluate the Gibbs free energy changes (deltaG) of the reactions catalyzed by purine nucleoside phosphorylase and uridine phosphorylase, respectively. A deltaG value of 0.59 kcal/mol for the combined reaction inosine+uracil <==> uridine+hypoxanthine was obtained, suggesting that at least in anoxic brain the system may readily respond to metabolite fluctuations. If purine nucleoside phosphorolysis and uridine phosphorolysis are coupled to uridine phosphorylation, catalyzed by uridine kinase, whose activity is relatively high in brain, the three enzyme activities will constitute a pyrimidine salvage pathway in which ribose 1-phosphate plays a pivotal role. CTP, presumably the last product of the pathway, and, to a lesser extent, UTP, exert inhibition on rat brain uridine nucleotides salvage synthesis, most likely at the level of the kinase reaction. On the contrary ATP and GTP are specific phosphate donors. (+info)The metabolism of isocytidine in Escherichia coli. (4/79)
Intact cells and cell-free extracts of E. coli convert isocytidine to isocytosine and uracil. The radioactive label of 5-[(3)H]isocytidine is incorporated into RNA and, DNA of growing bacteria at a rate equal to about 1.4% of that of cytidine under similar conditions; the radioactivity is found in uridylic, cytidylic and 2'-deoxythymidylic acids, while less than 0.4% of incorporated radioactive material might be due to possible incorporation of intact isocytidine. Uridine phosphorylase and cytidine deaminase apparently do not participate in the metabolic conversion of isocytidine.5-[(3)H]isocytidine was prepared by platinum-catalyzed dehalogenation of 5-bromoisocytidine in the presence of tritium. The 5-bromo derivative was obtained from 2',3'-0- -isopropylideneisocytidine by N-bromsuccinimide bromination followed by acidic hydrolysis. (+info)Isolation of an Escherichia coli mutant deficient in glutathione synthesis. (5/79)
A mutant of Escherichia coli that contains essentially no detectable glutathione has been isolated. The mutant contains a very low level of the enzyme glutathione synthetase and accumulates lambda-glutamyl cysteine at a concentration approximately equal to the level of glutathione found in its parent. No significant differences in growth were observed between the mutant and its parent. However, the activity of at least one enzyme was found to be affected by the absence of glutathione; the specific activity of the B1 subunit of ribonucleoside diphosphate reductase was greatly reduced. The possibility that the decreased B1 activity is due to a mutation in the structural gene coding for B1 or its regulatory gene could be eliminated. This suggests that one role of glutathione in the cell is to maintain at least this one protein in an active state. We propose the designation gshB for the gene coding for glutathione synthetase. (+info)Uridine phosphorylase association with vimentin. Intracellular distribution and localization. (6/79)
Uridine phosphorylase (UPase), a key enzyme in the pyrimidine salvage pathway, is associated with the intermediate filament protein vimentin, in NIH 3T3 fibroblasts and colon 26 cells. Affinity chromatography was utilized to purify UPase from colon 26 and NIH 3T3 cells using the uridine phosphorylase inhibitor 5'-amino benzylacyclouridine linked to an agarose matrix. Vimentin copurification with UPase was confirmed using both Western blot analysis and MALDI-MS methods. Separation of cytosolic proteins using gel filtration chromatography yields a high molecular weight complex containing UPase and vimentin. Purified recombinant UPase and recombinant vimentin were shown to bind in vitro with an affinity of 120 pm and a stoichiometry of 1:2. Immunofluorescence techniques confirm that UPase is associated with vimentin in both NIH 3T3 and colon 26 cells and that depolymerization of the microtubule system using nocodazole results in UPase remaining associated with the collapsed intermediate filament, vimentin. Our data demonstrate that UPase is associated with both the soluble and insoluble pools of vimentin. Approximately 60-70% of the total UPase exists in the cytosol as a soluble protein. Sequential extraction of NIH 3T3 or colon 26 cells liberates an additional 30-40% UPase activity associated with a detergent extractable fraction. All pools of UPase have been shown to possess enzymatic activity. We demonstrate for the first time that UPase is associated with vimentin and the existence of an enzymatically active cytoskeleton-associated UPase. (+info)Fluoropyrimidine sensitivity of human MCF-7 breast cancer cells stably transfected with human uridine phosphorylase. (7/79)
The relationship between uridine phosphorylase (UP) expression level in cancer cells and the tumour sensitivity to fluoropyrimidines is unclear. In this study, we found that UP overexpression by gene transfer, and the subsequent efficient metabolic activation of 5-fluorouracil (5-FU) by the ribonucleotide pathway, does not increase the fluoropyrimidine sensitivity of MCF-7 human cancer cells. (+info)p53-dependent suppression of uridine phosphorylase gene expression through direct promoter interaction. (8/79)
Uridine phosphorylase (UPase) is a key enzyme in the pyrimidine salvage pathway. It reversibly catalyzes the catabolism of uridine to uracil; controls the homeostatic regulation of uridine concentration in plasma and tissues; and plays a role in the intracellular activation of 5-fluorouracil. We cloned the murine UPase gene promoter, a 1703-bp fragment, and determined the transcription initiation sites located at +1 and +92 bp of the cDNA sequence. Through transient expression analysis of the 5'-flanking region of UPase gene, we have evaluated the promoter activity for a series of fragments with 5'- to 3'-deletion in murine breast cancer EMT-6 cells and immortalized murine fibroblast NIH 3T3 cells. Cotransfection of the UPase promoter constructs (from -1619 to -445) containing p53 binding motif with the wild-type p53 construct resulted in a significant reduction of luciferase activity; however, this effect disappeared with the additional deletion of the -445 to -274 sequence to suggest the existence in this promoter region of a putative p53 recognition element. Similar cotransfection in murine embryo fibroblasts p53-/- confirmed the inhibitory role of p53 on the UPase promoter activity. The specificity of the interaction is demonstrated by nuclear protein-specific binding to the putative p53 recognition sequence using gel mobility shift assay and DNase I footprinting analysis. These data indicate the UPase gene is a novel target of p53, and its expression is down-regulated by p53 at the promoter level. (+info)Uridine phosphorylase is an enzyme that plays a role in the metabolism of nucleosides, specifically uridine. The medical definition of 'uridine phosphorylase' is:
An enzyme (EC 2.4.2.3) involved in the reversible phosphorolysis of uridine to uracil and ribose-1-phosphate. This enzyme also catalyzes the phosphorolytic cleavage of other pyrimidine nucleosides, such as cytidine and thymidine, into their respective bases and ribose-1-phosphate. Uridine phosphorylase has a role in the salvage pathway of pyrimidine nucleotide biosynthesis and is found in various tissues, including the liver, intestines, and blood cells. Deficiency or dysfunction of uridine phosphorylase can lead to impaired nucleotide metabolism and may be associated with certain medical conditions, such as hereditary orotic aciduria.
Phosphorylases are enzymes that catalyze the phosphorolytic cleavage of a bond, often a glycosidic bond, in a carbohydrate molecule, releasing a sugar moiety and a phosphate group. This reaction is important in metabolic pathways such as glycogenolysis, where glycogen is broken down into glucose-1-phosphate by the action of glycogen phosphorylase. The resulting glucose-1-phosphate can then be further metabolized to produce energy. Phosphorylases are widely found in nature and play a crucial role in various biological processes, including energy metabolism and signal transduction.
Uridine kinase is an enzyme that phosphorylates the pyrimidine nucleoside uridine to produce uridine monophosphate (UMP). This reaction plays a crucial role in the salvage pathway of pyrimidine nucleotide synthesis, which recycles nucleosides generated from the degradation of RNA.
The human genome encodes two isoforms of uridine kinase, UCK1 and UCK2, which share a high degree of sequence similarity but have distinct tissue expression patterns and subcellular localization. UCK1 is primarily expressed in the liver and kidney, while UCK2 is more widely expressed in various tissues.
Uridine kinase activity has been implicated in several physiological processes, including the regulation of intracellular nucleotide pools, the biosynthesis of glycosaminoglycans and proteoglycans, and the modulation of antiviral responses. Dysregulation of uridine kinase activity has been associated with various pathological conditions, such as cancer, viral infections, and neurological disorders.
Pentosyltransferases are a group of enzymes that catalyze the transfer of a pentose (a sugar containing five carbon atoms) molecule from one compound to another. These enzymes play important roles in various biochemical pathways, including the biosynthesis of nucleotides, glycoproteins, and other complex carbohydrates.
One example of a pentosyltransferase is the enzyme that catalyzes the addition of a ribose sugar to form a glycosidic bond with a purine or pyrimidine base during the biosynthesis of nucleotides, which are the building blocks of DNA and RNA.
Another example is the enzyme that adds xylose residues to proteins during the formation of glycoproteins, which are proteins that contain covalently attached carbohydrate chains. These enzymes are essential for many biological processes and have been implicated in various diseases, including cancer and neurodegenerative disorders.
Uridine is a nucleoside that consists of a pyrimidine base (uracil) linked to a pentose sugar (ribose). It is a component of RNA, where it pairs with adenine. Uridine can also be found in various foods such as beer, broccoli, yeast, and meat. In the body, uridine can be synthesized from orotate or from the breakdown of RNA. It has several functions, including acting as a building block for RNA, contributing to energy metabolism, and regulating cell growth and differentiation. Uridine is also available as a dietary supplement and has been studied for its potential benefits in various health conditions.
Uracil is not a medical term, but it is a biological molecule. Medically or biologically, uracil can be defined as one of the four nucleobases in the nucleic acid of RNA (ribonucleic acid) that is linked to a ribose sugar by an N-glycosidic bond. It forms base pairs with adenine in double-stranded RNA and DNA. Uracil is a pyrimidine derivative, similar to thymine found in DNA, but it lacks the methyl group (-CH3) that thymine has at the 5 position of its ring.
Purine-nucleoside phosphorylase (PNP) is an enzyme that plays a crucial role in the metabolism of purines, which are essential components of nucleic acids (DNA and RNA). The medical definition of 'Purine-Nucleoside Phosphorylase' refers to the physiological function of this enzyme in the human body.
PNP is responsible for catalyzing the phosphorolytic cleavage of purine nucleosides, such as inosine and guanosine, into their respective purine bases (hypoxanthine and guanine) and ribose-1-phosphate. This reaction is essential for the recycling and salvage of purine bases, allowing the body to conserve energy and resources needed for de novo purine biosynthesis.
In a clinical or medical context, deficiencies in PNP activity can lead to serious consequences, particularly affecting the immune system and the nervous system. A genetic disorder called Purine-Nucleoside Phosphorylase Deficiency (PNP Deficiency) is characterized by significantly reduced or absent PNP enzyme activity, leading to an accumulation of toxic purine nucleosides and deoxypurine nucleosides. This accumulation can cause severe combined immunodeficiency (SCID), neurological impairments, and other complications, making it a critical area of study in medical research.
Thymidine phosphorylase (TP) is an enzyme that plays a role in the metabolism of nucleosides, specifically thymidine. The medical definition of thymidine phosphorylase is:
An enzyme that catalyzes the conversion of thymidine to thymine and deoxyribose-1-phosphate. Thymidine phosphorylase has been identified as a key enzyme in the angiogenic (formation of new blood vessels) pathway, where it facilitates the release of pro-angiogenic factors such as vascular endothelial growth factor (VEGF).
In addition to its role in nucleoside metabolism and angiogenesis, thymidine phosphorylase has been implicated in cancer biology. Increased levels of thymidine phosphorylase have been found in various human cancers, including colorectal, breast, lung, and pancreatic cancers. These high levels of thymidine phosphorylase are associated with poor prognosis and increased angiogenesis, contributing to tumor growth and metastasis.
Thus, thymidine phosphorylase is a crucial enzyme in nucleoside metabolism, angiogenesis, and cancer biology, making it an important target for the development of novel anti-cancer therapies.
Floxuridine is a chemotherapeutic antimetabolite medication that is primarily used in the treatment of colon cancer. It is a fluorinated pyrimidine nucleoside analogue, which means it is similar in structure to the building blocks of DNA and RNA, and can be incorporated into these molecules during cell division, disrupting their normal function and preventing cell replication.
Floxuridine works by inhibiting the enzyme thymidylate synthase, which is necessary for the synthesis of thymidine, a nucleoside that is essential for DNA replication. By blocking this enzyme, floxuridine can prevent the growth and proliferation of cancer cells.
Floxuridine is often used in combination with other chemotherapy drugs as part of a treatment regimen for colon cancer. It may be administered intravenously or via continuous infusion, depending on the specific treatment plan. As with all chemotherapy drugs, floxuridine can have significant side effects, including nausea, vomiting, diarrhea, and myelosuppression (suppression of bone marrow function), which can lead to anemia, neutropenia, and thrombocytopenia.
Phosphorylase Kinase (PhK) is a key enzyme in the regulation of glycogen metabolism, primarily involved in the breakdown of glycogen to glucose-1-phosphate. It is a serine/threonine protein kinase that catalyzes the phosphorylation of glycogen phosphorylase b, an isoform of glycogen phosphorylase, converting it into its active form, glycogen phosphorylase a.
PhK is composed of four different subunits: α, β, γ, and δ. The γ subunit contains the catalytic site, while the other subunits play regulatory roles. PhK itself can be activated by calcium ions (Ca2+) and protein kinase A (PKA)-mediated phosphorylation.
Phosphorylase Kinase is primarily located in the sarcoplasmic reticulum of muscle cells, where it plays a crucial role in regulating energy production during muscle contraction and relaxation. Dysregulation or mutations in PhK have been implicated in several genetic disorders, such as Debré-akaki syndrome, which is characterized by muscle weakness and cardiac abnormalities.
Ribose monophosphates are organic compounds that play a crucial role in the metabolism of cells, particularly in energy transfer and nucleic acid synthesis. A ribose monophosphate is formed by the attachment of a phosphate group to a ribose molecule, which is a type of sugar known as a pentose.
In biochemistry, there are two important ribose monophosphates:
1. Alpha-D-Ribose 5-Phosphate (ADP-Ribose): This compound serves as an essential substrate in various cellular processes, including DNA repair, chromatin remodeling, and protein modification. The enzyme that catalyzes the formation of ADP-ribose is known as poly(ADP-ribose) polymerase (PARP).
2. Ribulose 5-Phosphate: This compound is a key intermediate in the Calvin cycle, which is the process by which plants and some bacteria convert carbon dioxide into glucose during photosynthesis. Ribulose 5-phosphate is formed from ribose 5-phosphate through a series of enzymatic reactions.
Ribose monophosphates are essential for the proper functioning of cells and have implications in various physiological processes, as well as in certain disease states.
Phosphorylase b is a form of the enzyme glycogen phosphorylase, which is involved in the breakdown of glycogen, a large polymer of glucose, to glucose-1-phosphate. This enzyme plays a crucial role in carbohydrate metabolism, particularly during muscle contraction and liver glycogenolysis (the process of breaking down glycogen in the liver to release glucose into the bloodstream).
Phosphorylase b is an inactive form of the enzyme that can be converted to its active form, phosphorylase a, through the addition of a phosphate group by another enzyme called phosphorylase kinase. This conversion is part of a signaling cascade that activates glycogen breakdown in response to hormonal signals (such as epinephrine or glucagon) and metabolic demands (like muscle contraction).
The interconversion between phosphorylase b and phosphorylase a is an essential mechanism for regulating glycogen metabolism, allowing the body to rapidly respond to changing energy needs.
Phosphorylase a is an enzyme that plays a crucial role in the breakdown and metabolism of glycogen, a complex carbohydrate stored primarily in the liver and muscles. It is a phosphorylated form of the enzyme glycogen phosphorylase, which is activated by the addition of a phosphate group.
Phosphorylase a catalyzes the rate-limiting step in glycogenolysis, the process of breaking down glycogen into glucose-1-phosphate, which can then be converted into glucose and used for energy production. The activation of phosphorylase a is mediated by hormones such as adrenaline (epinephrine) and glucagon, which stimulate the enzyme phosphorylase kinase to add a phosphate group to inactive phosphorylase b, converting it to active phosphorylase a.
Phosphorylase a is composed of two identical subunits, each containing a catalytic site and a regulatory site that binds to ATP, glucose, and other molecules. The enzyme's activity is regulated by several factors, including the concentration of glucose, the presence of calcium ions, and the phosphorylation state of the enzyme.
In summary, Phosphorylase a is a key enzyme in glycogen metabolism that catalyzes the breakdown of glycogen into glucose-1-phosphate, providing energy for the body's cells. Its activity is regulated by hormones and other factors, making it an important component of the body's energy homeostasis.
Hymenolepis is a genus of tapeworms that are commonly found in rodents and other small mammals, but can also infect humans. The two species that are most relevant to human health are Hymenolepis nana and Hymenolepis diminuta.
Hymenolepis nana, also known as the dwarf tapeworm, is the smallest tapeworm that infects humans. It is unique among tapeworms because it can complete its entire life cycle within a single host, without needing an intermediate host. This means that it can be transmitted directly from person to person through contaminated food or water.
Hymenolepis diminuta, on the other hand, requires an intermediate host, such as a beetle or grain moth, to complete its life cycle. Humans can become infected by accidentally ingesting these insects, which may be found in contaminated grains or other food products.
Both species of Hymenolepis can cause similar symptoms in humans, including abdominal pain, diarrhea, and weight loss. In severe cases, they can also lead to more serious complications such as intestinal obstruction or nutritional deficiencies.
It's worth noting that while Hymenolepis infections are not uncommon in certain parts of the world, they are relatively rare in developed countries with good sanitation and hygiene practices. Treatment typically involves taking medication to kill the tapeworms, such as niclosamide or praziquantel.
Pyrimidine nucleosides are organic compounds that consist of a pyrimidine base (a heterocyclic aromatic ring containing two nitrogen atoms and four carbon atoms) linked to a sugar molecule, specifically ribose or deoxyribose, via a β-glycosidic bond. The pyrimidine bases found in nucleosides can be cytosine (C), thymine (T), or uracil (U). When the sugar component is ribose, it is called a pyrimidine nucleoside, and when it is linked to deoxyribose, it is referred to as a deoxy-pyrimidine nucleoside. These molecules play crucial roles in various biological processes, particularly in the structure and function of nucleic acids such as DNA and RNA.
Glycogen phosphorylase is an enzyme that plays a crucial role in the breakdown of glycogen, a stored form of glucose, to provide energy for the body's needs. This enzyme is primarily located in the liver and muscles.
In the process of glycogenolysis, glycogen phosphorylase catalyzes the phosphorolytic cleavage of the α-1,4-glycosidic bonds between glucose units in glycogen, releasing glucose-1-phosphate. This reaction does not involve water, unlike hydrolysis, making it more energy efficient. The glucose-1-phosphate produced can then be further metabolized to yield ATP and other energy-rich compounds through the glycolytic pathway.
Glycogen phosphorylase exists in two interconvertible forms: the active a form and the less active b form. The conversion between these forms is regulated by various factors, including hormones (such as insulin, glucagon, and epinephrine), enzymes, and second messengers (like cyclic AMP). Phosphorylation and dephosphorylation of the enzyme are critical in this regulation process. When glycogen phosphorylase is phosphorylated, it becomes activated, leading to increased glycogen breakdown; when it's dephosphorylated, it becomes less active or inactive, slowing down glycogenolysis.
Understanding the function and regulation of glycogen phosphorylase is essential for comprehending energy metabolism, particularly during periods of fasting, exercise, and stress when glucose availability from glycogen stores becomes crucial.
Uridine phosphorylase
UPP1
Vimentin
Deoxyuridine phosphorylase
Pyrimidine phosphorylase
UDP-N-acetylglucosamine diphosphorylase
UPH
Nucleotide salvage
Purine nucleoside phosphorylase
Uridine monophosphate synthase
List of EC numbers (EC 2)
Glycogen synthase
List of MeSH codes (D08)
Cyclic nucleotide
Galactose epimerase deficiency
Glycogen branching enzyme
Glycosidic bond
Glucose 6-phosphate
Vidarabine
Glycogen
Regulatory enzyme
Tipiracil
List of biomolecules
Floxuridine
Metabolism
Inborn errors of carbohydrate metabolism
List of EC numbers (EC 3)
Uridine phosphorylase - Wikipedia
3EUF: Crystal structure of BAU-bound human uridine phosphorylase 1
RCSB PDB - 1RXU: E. coli uridine phosphorylase: thymidine phosphate complex
WikiGenes - Upp1 - uridine phosphorylase 1
SCOPe 2.06: Superfamily c.56.2: Purine and uridine phosphorylases
1rxc.1 | SWISS-MODEL Template Library
Uridine(5')diphospho(1)-alpha-d-glucose. A binding study to glycogen phosphorylase b in the crystal - CAMS Oxford Institute
1lx7.1 | SWISS-MODEL Template Library
CATH Domain 1sj9C00
SCOP 1.69: Fold c.56: Phosphorylase/hydrolase-like
Peroxisome Proliferator-Activated Receptor γ Coactivator-1α Enhances Antiproliferative Activity of 5′-Deoxy-5-Fluorouridine in...
JCI -
Brain insulin action augments hepatic glycogen synthesis without suppressing glucose production or gluconeogenesis in dogs
CCCC 1975, Volume 40, Issue 8, Abstracts pp. 2353-2363, Articles by the same authors | Collection of Czechoslovak Chemical...
Frontiers | Integrative Metabolomics, Proteomics and Transcriptomics Analysis Reveals Liver Toxicity of Mesoporous Silica...
Concise Synthesis of Molnupiravir - ChemistryViews
Division of Medical Physics - Research output
- Research Profiles at Washington University School of Medicine
Decreased levels of UMP kinase as a mechanism of fluoropyrimidine resistance - Fingerprint - Albert Einstein College of...
wFleaBase: Results
3FWP | Genus
CCCC 1956, Volume 21, Issue 4, Abstracts pp. 1035-1042, Articles by the same authors | Collection of Czechoslovak Chemical...
BILD HRAS ONCOGENIC SIGNATURE
961-07-9|2-Amino-9-((2R,4S,5R)-4-hydroxy-5-(hydroxymethyl)tetrahydrofuran-2-yl)-3,9-dihydro-6H-purin-6-one| Ambeed
Planteome: Term Details for 'pentosyltransferase activity' (GO:0016763)
Homology by BLASTX
EC 2.4.2
GSE29949 CD8 NEG DC SPLEEN VS MONOCYTE BONE MARROW UP
The role of interferon-α as a modulator of fluorouracil and leucovorin<...
Tadhg Begley - Texas A&M University (TAMU) Scholar
Crystallography Reports Volume 60 Issue 2 | DeepDyve
"sequence id","alias","species","description",...
Escherichia1
- Crystal structures of escherichia coli uridine phosphorylase in two native and three complexed forms reveal basis of substrate specificity, induced conformational changes and influence of potassium. (expasy.org)
Phosphate5
- In enzymology, an uridine phosphorylase (EC 2.4.2.3) is an enzyme that catalyzes the chemical reaction uridine + phosphate ⇌ {\displaystyle \rightleftharpoons } uracil + alpha-D-ribose 1-phosphate Thus, the two substrates of this enzyme are uridine and phosphate, whereas its two products are uracil and alpha-D-ribose 1-phosphate. (wikipedia.org)
- The systematic name of this enzyme class is uridine:phosphate alpha-D-ribosyltransferase. (wikipedia.org)
- Uridine phosphorylase (UP) is a key enzyme in the pyrimidine salvage pathway that catalyses the reversible phosphorolysis of uridine to uracil and ribose 1-phosphate. (rcsb.org)
- Uridine + phosphate = uracil + alpha-D-ribose 1-phosphate. (cathdb.info)
- Then, the resulting 5-isobutyryl ribose was converted to ribosyl-1-phosphate and reacted with uracil using several optimized enzymes, including an engineered ribosyl-1-kinase and uridine phosphorylase. (chemistryviews.org)
Uracil4
- Uridine phosphorylase (UPase) catalyzes the reversible conversion of uridine into uracil and contributes to the antineoplastic activity of 5′-deoxy-5-fluorouridine (5′-DFUR) and homeostasis of uridine levels in plasma and tissues. (aspetjournals.org)
- Exogenous uridine and cytidine are mostly converted to uracil by uridine phosphorylase and cytidine deaminase in T. foetus prior to incorporation. (tmu.edu.tw)
- IC50 values did not significantly differ between CU428 and NP1 for the same analog at either room temperature or 37°C. To investigate the mechanism of inhibition, we used two pyrimidine bases (uracil and thymine) and three nucleosides (uridine, thymidine, and 5-methyluridine) to determine whether the inhibitory effects from the pyrimidine analogs were reversible. (bvsalud.org)
- UPP1 codes for (synthesizes) the enzyme uridine phosphorylase (UP), also known as uridine-uracil phosphoribosyltransferase, which is responsible for the metabolic breakdown of uridine, a process that generates energy-rich metabolites that the cells can use. (acsh.org)
UPP11
- Given that glucose availability influences the use of uridine-derived ribose, we hypothesized that a glucose-depleted microenvironment triggers [pancreatic cancer cells] to upregulate UPP1 [the gene that makes an enzyme that breaks down uridine] as a compensatory response. (acsh.org)
Nucleoside3
- These hexameric structures confirm the overall structural similarity of UP to E.coli purine nucleoside phosphorylase (PNP) whereby, in the presence of substrate, each displays a closed conformation resulting from a concerted movement that closes the active site cleft. (rcsb.org)
- 1. Agarwal, R.P. and Parks, R.E. Purine nucleoside phosphorylase from human erythrocytes. (qmul.ac.uk)
- 2. Friedkin, M. and Kalckar, H. Nucleoside phosphorylases. (qmul.ac.uk)
Coli1
- Substrate specificity of E. coli uridine phosphorylase. (cas.cz)
Thymidine phosphorylase activity1
- Like P. acidovorans, P. aeruginosa lacked thymidine phosphorylase activity. (microbiologyresearch.org)
Diphosphate4
- Eventually, uridine diphosphate (UDP) and uridine triphosphate (UTP) are produced down the biosynthetic pathway by kinases and dephosphorylation of ATPs. (biologyonline.com)
- R) The chemical structure of uridine diphosphate, an alternate fuel for pancreatic cancer cells. (acsh.org)
- Note that uridine diphosphate contains ribose, which is similar to glucose. (acsh.org)
- UDPG=uridine diphosphate-glucose. (medscape.com)
Monophosphate2
- The underlying mechanism(s) have varied in different cancer cell lines, and include increased fluorouracil anabolism to fluorodeoxyuridine monophosphate, further inhibition of thymidylate synthase, stimulation of thymidine and uridine phosphorylase activities, greater DNA damage, and enhanced natural killer cell-mediated lysis of tumour targets. (nebraska.edu)
- OMP is then decarboxylated by the enzyme OMP decarboxylase to yield uridine monophosphate (UMP). (biologyonline.com)
UPase1
- This study demonstrates uridine phosphorylase as a novel target gene of PGC-1α, which induces the transcription and enzymatic activity of UPase in various cancer cells and thus augments their susceptibility to 5′-DFUR. (aspetjournals.org)
Salmonella1
- Preliminary investigation of the three-dimensional structure of Salmonella typhimurium uridine phosphorylase in the crystalline state. (cathdb.info)
Deoxyuridine2
- The synthesis and base pairing properties of platinum complexes based on uridine and deoxyuridine nucleosides and preliminary studies of their antiproliferative activity are described. (bvsalud.org)
- Platinum(II) uridine and deoxyuridine complexes were synthesized by C-I oxidative addition to Pt(0)(PPh3)4. (bvsalud.org)
Fluorouracil1
- Inhibiting liver UP in humans raises blood uridine levels and produces a protective effect ("uridine rescue") against the toxicity of the chemotherapeutic agent 5-fluorouracil without reducing its antitumour activity. (rcsb.org)
Glucose3
Induction1
- The induction of thymidine phosphorylase and excretion of deoxyribose during thymine starvation. (microbiologyresearch.org)
Homeostasis1
- Taken together, our results corroborate the regulatory function of PGC-1α in uridine homeostasis and imply its links with the energy metabolism. (aspetjournals.org)
Source1
- It's because cancer cells are perfectly willing to switch to another fuel source - uridine (Figure 1). (acsh.org)
Similar1
- PREDICTED: similar to Uridine phosp. (nig.ac.jp)
Nucleoside6
- 16. Differences in activities and substrate specificity of human and murine pyrimidine nucleoside phosphorylases: implications for chemotherapy with 5-fluoropyrimidines. (nih.gov)
- UPP1, or uridine phosphorylase 1, is a pyrimidine nucleoside phosphorylase. (nih.gov)
- Pyrimidine nucleoside phosphorylases can add ribose or deoxyribose to pyrimidine bases to form nucleosides that can be incorporated into RNA or DNA. (nih.gov)
- In the last 10 years, the scientific interests of I.A. Mikhailopulo focused on studying the mechanism of functioning of nucleoside phosphorylases (NF), the mechanisms of substrate binding and its activation in the catalytic center of these enzymes. (gov.by)
- Academician Miroshnikov A.I.). One of the most interesting results of this period of work is the establishment of the important role of the serine-90 catalytic center of purine nucleoside phosphorylase (PNP) from E. coli in the binding and activation of a number of substrates. (gov.by)
- Shows substrate specificity and accept uridine, deoxyuridine, and thymidine as well as the two pyrimidine nucleoside analogs 5-fluorouridine and 5-fluoro-2(')-deoxyuridine as substrates. (nih.gov)
UPP21
- Metabolite profiling revealed that uracil accumulates in the livers of these mice due to increased uridine phosphorylase UPP2 activity. (bvsalud.org)
Thymidine phosphorylase inhibitor1
- Trifluridine (trye flure' i deen)/tipiracil (tye pir' a sil) combines an antineoplastic pyrimidine analogue (2-deoxy-5-trifluoromethyl uridine) with a thymidine phosphorylase inhibitor that blocks its rapid metabolism, thus increasing the bioavailability of trifluridine. (nih.gov)
Kinase3
- 6. Key role of uridine kinase and uridine phosphorylase in the homeostatic regulation of purine and pyrimidine salvage in brain. (nih.gov)
- Fluorouridine monophosphate is directly generated from 5FU by the action of orotate phosphoribosyl transferase (OPRT), or is sequentially converted from 5FU by the actions of uridine phosphorylase (UP) and uridine kinase (UK). (medscape.com)
- Then, the resulting 5-isobutyryl ribose was converted to ribosyl-1-phosphate and reacted with uracil using several optimized enzymes, including an engineered ribosyl-1-kinase and uridine phosphorylase. (chemistryviews.org)
Alpha-D-ribosyltransferase1
- The systematic name of this enzyme class is uridine:phosphate alpha-D-ribosyltransferase. (wikipedia.org)
Inhibitor1
- UDP-glucose is an R-state inhibitor of glycogen phosphorylase b, competitive with the substrate, glucose 1-phosphate and noncompetitive with the allosteric activator, AMP. (ox.ac.uk)
Uracil and ribose1
- An enzyme that catalyzes the transfer of ribose from uridine to orthophosphate, forming uracil and ribose 1-phosphate. (nih.gov)
Glucose4
- Uridine(5')diphospho(1)-alpha-D-glucose. (ox.ac.uk)
- Diffusion of 100 mM UDP-glucose into crystals of phosphorylase b resulted in a difference Fourier synthesis at 0.3-nm resolution that showed two peaks: (a) binding at the allosteric site and (b) binding at the catalytic site. (ox.ac.uk)
- The pyrophosphate is also well located with the glucose phosphate interacting with the main-chain NH groups at the start of the glycine-loop alpha helix and the uridine phosphate interacting through a water molecule with the 5'-phosphate of the cofactor pyridoxal phosphate and with the side chains of residues Tyr-573, Lys-574 and probably Arg-569. (ox.ac.uk)
- 9. Uridine Metabolism and Its Role in Glucose, Lipid, and Amino Acid Homeostasis. (nih.gov)
Vibrio1
- 4LNH: Crystal structure of uridine phosphorylase from Vibrio fischeri ES114, NYSGRC Target 29520. (rcsb.org)
Isoforms1
- Several tissue-specific isoforms of phosphorylase are noted. (medscape.com)
Glycogen1
- A binding study to glycogen phosphorylase b in the crystal. (ox.ac.uk)
Nucleotide1
- 10. Abnormalities in uridine homeostatic regulation and pyrimidine nucleotide metabolism as a consequence of the deletion of the uridine phosphorylase gene. (nih.gov)
Ribose 1-phosphate1
- In enzymology, an uridine phosphorylase (EC 2.4.2.3) is an enzyme that catalyzes the chemical reaction uridine + phosphate ⇌ {\displaystyle \rightleftharpoons } uracil + alpha-D-ribose 1-phosphate Thus, the two substrates of this enzyme are uridine and phosphate, whereas its two products are uracil and alpha-D-ribose 1-phosphate. (wikipedia.org)
Regulation1
- Vitamin D Regulation of the Uridine Phosphorylase 1 Gene and Uridine-Induced DNA Damage in Colon in African Americans and European Americans. (uchicago.edu)
Tipiracil1
- Trifluridine triphosphate is metabolized by thymidine phosphorylase which is inhibited by tipiracil, thus providing a longer half-life and increased intracellular concentrations of active phosphorylated trifluridine. (nih.gov)
Pyrimidine metabolism2
Liver3
Trifluridine1
- Trifluridine is metabolized in most cells by thymidine phosphorylase to 5-trilfuorosmethyluracil, which is inactive. (nih.gov)
Analysis1
- However the position of the uridine cannot be located although analysis by thin-layer chromatography showed that no degradation had taken place. (ox.ac.uk)
