25609-92-1Relevant articles and documents
Cell- And Polymerase-Selective Metabolic Labeling of Cellular RNA with 2′-Azidocytidine
Wang, Danyang,Zhang, Yu,Kleiner, Ralph E.
supporting information, p. 14417 - 14421 (2020/10/13)
Metabolic labeling of cellular RNA is a powerful approach to investigate RNA biology. In addition to revealing whole transcriptome dynamics, targeted labeling strategies can be used to study individual RNA subpopulations within complex systems. Here, we describe a strategy for cell- and polymerase-selective RNA labeling with 2′-azidocytidine (2′-AzCyd), a modified nucleoside amenable to bioorthogonal labeling with SPAAC chemistry. In contrast to 2′-OH-containing pyrimidine ribonucleosides, which rely upon uridine-cytidine kinase 2 (UCK2) for activation, 2′-AzCyd is phosphorylated by deoxycytidine kinase (dCK), and we find that expression of dCK mediates cell-selective 2′-AzCyd labeling. Further, 2′-AzCyd is primarily incorporated into rRNA and displays low cytotoxicity and high labeling efficiency. We apply our system to analyze the turnover of rRNA during ribophagy induced by oxidative stress or mTOR inhibition to show that 28S and 18S rRNAs undergo accelerated degradation. Taken together, our work provides a general approach for studying dynamic RNA behavior with cell and polymerase specificity and reveals fundamental insights into nucleotide and nucleic acid metabolism.
Fully automated continuous meso-flow synthesis of 5′-nucleotides and deoxynucleotides
Zhu, Chenjie,Tang, Chenglun,Cao, Zhi,He, Wei,Chen, Yong,Chen, Xiaochun,Guo, Kai,Ying, Hanjie
, p. 1575 - 1581 (2015/02/19)
The first continuous meso-flow synthesis of natural and non-natural 5′-nucleotides and deoxynucleotides is described, representing a significant advance over the corresponding in-flask method. By means of this meso-flow technique, a synthesis with time consumption and high-energy consumption becomes facile to generate products with great efficiency. An abbreviated duration, satisfactory output, and mild reaction conditions are expected to be realized under the present procedure.
Immobilized Drosophila melanogaster deoxyribonucleoside kinase (DmdNK) as a high performing biocatalyst for the synthesis of purine arabinonucleotides
Serra, Immacolata,Conti, Silvia,Piskur, Jure,Clausen, Anders R.,Munch-Petersen, Birgitte,Terreni, Marco,Ubiali, Daniela
, p. 563 - 570 (2014/05/20)
Fruit fly (Drosophila melanogaster) deoxyribonucleoside kinase (DmdNK; EC: 2.7.1.145) was characterized for its substrate specificity towards natural and non-natural nucleosides, confirming its potential in the enzymatic synthesis of modified nucleotides. DmdNK was adsorbed on a solid ion exchange support (bearing primary amino groups) achieving an expressed activity >98%. Upon cross-linking with aldehyde dextran, expressed activity was 30-40%. Both biocatalysts (adsorbed or cross-linked) were stable at pH 10 and room temperature for 24 h (about 70% of retained activity). The cross-linked DmdNK preparation was used for the preparative synthesis of arabinosyladenine monophosphate (araA-MP) and fludarabine monophosphate (FaraAMP). Upon optimization of the reaction conditions (50 mM ammonium acetate, substrate/ATP ratio= 1:1.25, 2 mM MgCl2, 378C, pH 8) immobilized DmdNK afforded the title nucleotides with high conversion (>90%), whereas with the soluble enzyme lower conversions were achieved (78-87%). Arabinosyladenine monophosphate was isolated in 95% yield and high purity (96.5%).
Two thymidine kinases and one multisubstrate deoxyribonucleoside kinase salvage DNA precursors in Arabidopsis thaliana
Clausen, Anders R.,Girandon, Lenart,Ali, Ashfaq,Knecht, Wolfgang,Rozpedowska, Elzbieta,Sandrini, Michael P. B.,Andreasson, Erik,Munch-Petersen, Birgitte,Piskur, Jure
, p. 3889 - 3897 (2013/01/13)
Deoxyribonucleotides are the building blocks of DNA and can be synthesized via de novo and salvage pathways. Deoxyribonucleoside kinases (EC 2.7.1.145) salvage deoxyribonucleosides by transfer of a phosphate group to the 5' of a deoxyribonucleoside. This salvage pathway is well characterized in mammals, but in contrast, little is known about how plants salvage deoxyribonucleosides. We show that during salvage, deoxyribonucleosides can be phosphorylated by extracts of Arabidopsis thaliana into corresponding monophosphate compounds with an unexpected preference for purines over pyrimidines. Deoxyribonucleoside kinase activities were present in all tissues during all growth stages. In the A. thaliana genome, we identified two types of genes that could encode enzymes which are involved in the salvage of deoxyribonucleosides. Thymidine kinase activity was encoded by two thymidine kinase 1 (EC 2.7.1.21)-like genes (AtTK1a and AtTK1b). Deoxyadenosine, deoxyguanosine and deoxycytidine kinase activities were encoded by a single AtdNK gene. T-DNA insertion lines of AtTK1a and AtTK1b mutant genes had normal growth, although AtTK1a AtTK1b double mutants died at an early stage, which indicates that AtTK1a and AtTK1b catalyze redundant reactions. The results obtained in the present study suggest a crucial role for the salvage of thymidine during early plant development. 2012 The Authors Journal compilation
A single nuclease-resistant linkage in DNA as a versatile tool for the characterization of DNA lesions: Application to the guanine oxidative lesion g+34 generated by metalloporphyrin/KHSO5 reagent
Tomaszewska, Agnieszka,Mourgues, Sophie,Guga, Piotr,Nawrot, Barbara,Pratviel, Genevieve
, p. 2505 - 2512 (2013/01/15)
The oxidation of an oligonucleotide containing a single nuclease-resistant phosphodiester link, a stereoisomerically pure methylphosphonate, by manganese (Mn-TMPyP) or iron (Fe-TMPyP) porphyrin associated to KHSO5 allowed the isolation and characterization of a guanine lesion corresponding to an increase of mass of 34 amu as compared to guanine ( G+34 ), namely, 5-carboxamido-5-formamido-2-iminohydantoin. Enzymatic digestion of the damaged oligonucleotide afforded, apart from the undamaged nucleotide monomer pool, a unique dinucleotide doubly modified with a methylphosphonate and an oxidized guanine base that is suitable for NMR analysis. The method can be applied to the study of any DNA lesion. More importantly, the method can be extended to the analysis of DNA damage in a sequence context. Any preselected residue in a DNA sequence may be individually analyzed by the easy introduction of a single nuclease-resistant link at the 3′- or 5′-position.
Mechanism of the alkali degradation of (6-4) photoproduct-containing DNA
Arichi, Norihito,Inase, Aki,Eto, Sachise,Mizukoshi, Toshimi,Yamamoto, Junpei,Iwai, Shigenori
body text, p. 2318 - 2325 (2012/04/10)
The (6-4) photoproduct is one of the major damaged bases produced by ultraviolet light in DNA. This lesion is known to be alkali-labile, and strand breaks occur at its sites when UV-irradiated DNA is treated with hot alkali. We have analyzed the product obtained by the alkali treatment of a dinucleoside monophosphate containing the (6-4) photoproduct, by HPLC, NMR spectroscopy, and mass spectrometry. We previously found that the N3-C4 bond of the 5′ component was hydrolyzed by a mild alkali treatment, and the present study revealed that the following reaction was the hydrolysis of the glycosidic bond at the 3′ component. The sugar moiety of this component was lost, even when a 3′-flanking nucleotide was not present. Glycosidic bond hydrolysis was also observed for a dimer and a trimer containing 5-methyl-2-pyrimidinone, which was used as an analog of the 3′ component of the (6-4) photoproduct, and its mechanism was elucidated. Finally, the alkali treatment of a tetramer, d(GT(6-4)TC), yielded 2′-deoxycytidine 5′-monophosphate, while 2′-deoxyguanosine 3′-monophosphate was not detected. This result demonstrated the hydrolysis of the glycosidic bond at the 3′ component of the (6-4) photoproduct and the subsequent strand break by β-elimination. It was also shown that the glycosidic bond at the 3′ component of the Dewar valence isomer was more alkali-labile than that of the (6-4) photoproduct. The Royal Society of Chemistry 2012.
Evaluation of the role of three candidate human kinases in the conversion of the hepatitis C virus inhibitor 2′-C-methyl-cytidine to its 5′-monophosphate metabolite
Golitsina, Nina L.,Danehy Jr., Francis T.,Fellows, Ross,Cretton-Scott, Erika,Standring, David N.
experimental part, p. 470 - 481 (2010/12/19)
Nucleoside analogs are effective inhibitors of the hepatitis C virus (HCV) in the clinical setting. One such molecule, 2′-C-methyl-cytidine (2′-MeC), entered clinical development as NM283, a valine ester prodrug form of 2′-MeC possessing improved oral bioavailability. To be active against HCV, 2′-MeC must be converted to 2′-MeC triphosphate which inhibits NS5B, the HCV RNA-dependent RNA polymerase. Conversion of 2′-MeC to 2′-MeC monophosphate is the first step in 2′-MeC triphosphate production and is thought to be the rate-limiting step. Here we investigate which of three possible enzymes, deoxycytidine kinase (dCK), uridine-cytidine kinase 1 (UCK1), or uridine-cytidine kinase 2 (UCK2), mediate this first phosphorylation step. Purified recombinant enzymes UCK2 and dCK, but not UCK1, could phosphorylate 2′-MeC in vitro. However, siRNA knockdown experiments in three human cell lines (HeLa, Huh7 and HepG2) defined UCK2 and not dCK as the key kinase for the formation of 2′-MeC monophosphate in cultured human cells. These results underscore the importance of confirming enzymatic kinase data with appropriate cell-based assays. Finally, we present data suggesting that inefficient phosphorylation by UCK2 likely limits the antiviral activity of 2′-MeC against HCV. This paves the way for the use of a nucleotide prodrug approach to overcome this limitation.
Mechanism of activation of β-D-2′-Deoxy-2′-fluoro- 2′-C-methylcytidine and inhibition of hepatitis C virus NS5B RNA polymerase
Murakami, Eisuke,Bao, Haiying,Ramesh, Mangala,McBrayer, Tamara R.,Whitaker, Tony,Steuer, Holly M. Micolochick,Schinazi, Raymond F.,Stuyver, Lieven J.,Obikhod, Aleksandr,Otto, Michael J.,Furman, Phillip A.
, p. 503 - 509 (2008/02/07)
β-D-2′-Deoxy-2′-fluoro-2′-C-methylcytidine (PSI-6130) is a potent specific inhibitor of hepatitis C virus (HCV) RNA synthesis in Huh-7 replicon cells. To inhibit the HCV NS5B RNA polymerase, PSI-6130 must be phosphorylated to the 5′-triphosphate form. The phosphorylation of PSI-6130 and inhibition of HCV NS5B were investigated. The phosphorylation of PSI-6130 by recombinant human 2′-deoxycytidine kinase (dCK) and uridine-cytidine kinase 1 (UCK-1) was measured by using a coupled spectrophotometric reaction. PSI-6130 was shown to be a substrate for purified dCK, with a Km of 81 μM and a kcat of 0.007 s -1, but was not a substrate for UCK-1. PSI-6130 monophosphate (PSI-6130-MP) was efficiently phosphorylated to the diphosphate and subsequently to the triphosphate by recombinant human UMP-CMP kinase and nucleoside diphosphate kinase, respectively. The inhibition of wild-type and mutated (S282T) HCV NS5B RNA polymerases was studied. The steady-state inhibition constant (Ki) for PSI-6130 triphosphate (PSI-6130-TP) with the wild-type enzyme was 4.3 μM. Similar results were obtained with 2′-C-methyladenosine triphosphate (Ki = 1.5 μM) and 2′-C-methylcytidine triphosphate (Ki = 1.6 μM). NS5B with the S282T mutation, which is known to confer resistance to 2′-C- methyladenosine, was inhibited by PSI-6130-TP as efficiently as the wild type. Incorporation of PSI-6130-MP into RNA catalyzed by purified NS5B RNA polymerase resulted in chain termination. Copyright
Enantio-selectivity of human nucleoside monophosphate kinases
Alexandre,Roy,Topalis,Perigaud,Deville-Bonne
, p. 1375 - 1379 (2008/12/23)
Over recent years, there has been a renewed interest in the development of L-nucleosides as safe and efficacious drugs for the treatment of viral infections. Biological activity of these compounds requires phosphorylation to their triphosphate form, involving nucleoside monophosphate kinases in the second step. In order to characterize the activation pathway of L-nucleosides of the pyrimidine series, we studied the enantio-selectivity of human uridylate-cytidylate and thymidylate kinases. The results showed that these enzymes are only weakly enantio-selective and are thus probably involved in the activation of L-nucleosides in vivo. An activation pathway for telbivudine (L-dT) was therefore proposed. Copyright Taylor & Francis Group, LLC.
COMPOUNDS FOR IMMUNOPOTENTIATION
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Page/Page column 151, (2010/02/15)
Methods of stimulating an immune response and treating patients responsive thereto with 3,4-di(1H-indol-3-yl)-1H-pyrrole-2,5-diones, staurosporine analogs, derivatized pyridazines, chromen-4-ones, indolinones, quinazolines, nucleoside analogs, and other small molecules are disclosed.