C18H23N4O14P(C9H11N2O8P)n
|
|
5'-Uridylic acid, homopolymer
|
ChemIDplus
|
Poly U
|
ChemIDplus
|
poly(U)
|
CBN
|
Polyuridylic acid
|
ChemIDplus
|
Uracil polynucleotide
|
ChemIDplus
|
27416-86-0
|
CAS Registry Number
|
ChemIDplus
|
Zhu M, Xu L, Chen X, Ma Z, Wang H, Ng TB (2013) A novel ribonuclease with HIV-1 reverse transcriptase inhibitory activity from the edible mushroom Hygrophorus russula. Applied biochemistry and biotechnology 170, 219-230 [PubMed:23494217] [show Abstract] A 28-kDa ribonuclease, with an optimum pH of 4.0 and an optimum temperature at 58 °C, was isolated from fruiting bodies of the edible mushroom Hygrophorus russula. It was purified by ion exchange chromatography on carboxymethyl-cellulose, dithyaminoethyl-cellulose, quaternary amine-sepharose and sulphopropyl-sepharose, followed by fast protein liquid chromatography gel filtration on Superdex 75. The N-terminal amino acid sequence was ASAGG which showed homology to those of other fungal RNases to some degree. It exerted the highest RNase activity on poly C and poly U. The Michaelis constant (K(m)) value of the RNase on yeast tRNA was 3.6 μM, and the maximal velocity (V(max)) was 0.6 μM. The RNase activity was suppressed by some ions including Fe(2+) and Zn(2+) ions. The RNase inhibited the activity of HIV-1 reverse transcriptase with an IC(50) of 4.64 μM. | Crespo MI, Zacca ER, Núñez NG, Ranocchia RP, Maccioni M, Maletto BA, Pistoresi-Palencia MC, Morón G (2013) TLR7 triggering with polyuridylic acid promotes cross-presentation in CD8α+ conventional dendritic cells by enhancing antigen preservation and MHC class I antigen permanence on the dendritic cell surface. Journal of immunology (Baltimore, Md. : 1950) 190, 948-960 [PubMed:23284054] [show Abstract] ssRNA can interact with dendritic cells (DCs) through binding to TLR7, inducing secretion of proinflammatory cytokines and type I IFN. Triggering TLR7 enhances cross-priming of CD8(+) T cells, which requires cross-presentation of exogenous Ag to DCs. However, how TLR triggering can affect Ag cross-presentation is still not clear. Using OVA as an Ag model, we observed that stimulation of TLR7 in DCs by polyuridylic acid (polyU), a synthetic ssRNA analog, generates a strong specific cytotoxic response in C57BL/6 mice. PolyU stimulate CD8α(+) DCs to cross-prime naive CD8(+) T cells in a type I IFN-dependent fashion. This enhanced cross-priming is accompanied by a higher density of OVA(256-264)/H-2K(b) complexes on CD8α(+) DCs treated with polyU, as well as by upregulation of costimulatory molecules and increased secretion of proinflammatory cytokines by DCs. Cross-priming of CD8(+) T cells by DCs treated with polyU requires proteasome and Ag translocation to cytosol through the Sec61 channel in DCs. The observed enhancement in OVA cross-presentation with polyU in DCs could be mediated by a limited Ag degradation in endophagosomal compartments and a higher permanence of OVA peptide/MHC class I complexes on DCs. These observations clearly reveal that key steps of Ag processing for cross-presentation can be modulated by TLR ligands, opening new avenues for understanding their mechanisms as adjuvants of the immune response. | Shetlar MD, Hom K, Venditto VJ (2013) Photohydrate-mediated reactions of uridine, 2'-deoxyuridine and 2'-deoxycytidine with amines at near neutral pH. Photochemistry and photobiology 89, 869-877 [PubMed:23480256] [show Abstract] Photohydrates are formed in high yield when uridine (Urd), 2'-deoxyuridine (dUrd), cytidine (Cyd) and 2'-deoxycytidine (dCyd) are irradiated with UVC in aqueous solution. The thermal reactions of the photohydrates of Urd with amines at pH values near pH 7.5 have been studied using UV spectroscopy, HPLC, mass spectrometry and, in some cases, NMR. It has been found that a number of amines (i.e. ethylenediamine, N,N'-dimethylethylenediamine, glycine, glycinamide, glycylglycine, glycylgylcylglycine, putrescine, spermidine and spermine) react thermally with such hydrates to form products with UV spectra characteristic of opened ring uridine-amine adducts. In general, these products display a strong absorption peak with λmax in the range between 288 and 310 nm. Mass spectral studies of a number of the products indicate that they contain one molecule of parent nucleoside and one molecule of reactant amine. Upon standing in water these products revert to parent hydrate, while heating produces parent nucleoside. Less comprehensive studies indicate that photohydrates of dUrd and dCyd undergo analogous thermal reactions. Preliminary results suggest that UV-irradiated polyuridylic acid and polycytidylic acid undergo similar reactions. These results may have relevance for obtaining a complete understanding of the biological effects of producing Urd and dCyd photohydrates in a cellular environment. | Lunde BM, Magler I, Meinhart A (2012) Crystal structures of the Cid1 poly (U) polymerase reveal the mechanism for UTP selectivity. Nucleic acids research 40, 9815-9824 [PubMed:22885303] [show Abstract] Polyuridylation is emerging as a ubiquitous post-translational modification with important roles in multiple aspects of RNA metabolism. These poly (U) tails are added by poly (U) polymerases with homology to poly (A) polymerases; nevertheless, the selection for UTP over ATP remains enigmatic. We report the structures of poly (U) polymerase Cid1 from Schizoscaccharomyces pombe alone and in complex with UTP, CTP, GTP and 3'-dATP. These structures reveal that each of the 4 nt can be accommodated at the active site; however, differences exist that suggest how the polymerase selects UTP over the other nucleotides. Furthermore, we find that Cid1 shares a number of common UTP recognition features with the kinetoplastid terminal uridyltransferases. Kinetic analysis of Cid1's activity for its preferred substrates, UTP and ATP, reveal a clear preference for UTP over ATP. Ultimately, we show that a single histidine in the active site plays a pivotal role for poly (U) activity. Notably, this residue is typically replaced by an asparagine residue in Cid1-family poly (A) polymerases. By mutating this histidine to an asparagine residue in Cid1, we diminished Cid1's activity for UTP addition and improved ATP incorporation, supporting that this residue is important for UTP selectivity. | Komissarov AA, Calcutt MJ, Marchbank MT, Peletskaya EN, Deutsher SL (1996) Equilibrium binding studies of recombinant anti-single-stranded DNA Fab. Role of heavy chain complementarity-determining regions. The Journal of biological chemistry 271, 12241-12246 [PubMed:8647821] [show Abstract] We previously isolated nucleic acid-binding antibody fragments (Fab) from bacteriophage display libraries representing the immunoglobulin repertoire of automimune mice to expedite the analysis of antibody-DNA recognition. In the present study, the binding properties of one such anti-DNA Fab, high affinity single-stranded (ss) DNA-binding Fab (DNA-1), were defined using equilibrium gel filtration and fluorescence titration. Results demonstrated that DNA-1 had a marked preference for oligo(dT) (100 nM dissociation constant) and required oligo(dT) >5 nucleotides in length. A detailed analysis of the involvement of the individual heavy chain (H) complementarity-determining regions (CDR) ensued using previously constructed HCDR transplantation mutants between DNA-1 and low affinity ssDNA-binding Fab (D5), a Fab that binds poorly to DNA (Calcutt, M. J. Komissarov, A. A., Marchbank, M. T., and Deutscher, S. L. (1996) Gene (Amst.) 168, 9-14). Circular dichroism studies indicated that the wild type and mutant Fab studied were of similar overall secondary structure and may contain similar combining site shapes. The conversion of D5 to a high affinity oligo(dT)-binding Fab occurred only in the presence of DNA-1 HCDR3. Results with site-specific mutants in HCDR1 further suggested a role of residue 33 in interaction with nucleic acid. The results of these studies are compared with previously published data on DNA-antibody recognition. |
|