Search results for "nucleotides"

Musashi-2 contributes to myotonic dystrophy muscle dysfunction by promoting excessive autophagy through miR-7 biogenesis repression

2021

Skeletal muscle symptoms strongly contribute to mortality of myotonic dystrophy type 1 (DM1) patients. DM1 is a neuromuscular genetic disease caused by CTG repeat expansions that, upon transcription, sequester the Muscleblind-like family of proteins and dysregulate alternative splicing of hundreds of genes. However, mis-splicing does not satisfactorily explain muscle atrophy and wasting, and several other contributing factors have been suggested, including hyperactivated autophagy leading to excessive catabolism. MicroRNA ( miR ) -7 has been demonstrated to be necessary and sufficient to repress the autophagy pathway in cell models of the disease, but the origin of its low levels in DM1 was…

Self-assembly of monodisperse oligonucleotide-elastin block copolymers into stars and compound micelles.

2010

Prognostic Impact of let-7e MicroRNA and Its Target Genes in Localized High-Risk Intestinal GIST: A Spanish Group for Research on Sarcoma (GEIS) Study

2020

MicroRNAs (miRNAs) are small non-coding RNAs that negatively regulate gene expression at the post-transcriptional level, and they have been described as being associated with tumor prognosis. Here, miRNA profiling was planned to explore new molecular prognostic biomarkers in localized intestinal high-risk GIST. Paraffin tumor blocks of 14 and 86 patients were used in the discovery and expansion sets, respectively. GeneChip miRNA v3.0 was employed to identify the miRNAs differentially expressed between relapsed and non-relapsed patient samples, which were validated in the expansion set, by qRT-PCR. RT2 Profiler PCR Array was used for the screening of let-7e targets. Expression levels were co…

Analysis of pseudouridines and other RNA modifications using hydraPsiSeq protocol

2021

Detection of RNA modified nucleotides using deep sequencing can be performed by several approaches, including antibody-driven enrichment and natural or chemically induced RT signatures. However, only very few RNA modified nucleotides generate natural RT signatures and antibody-driven enrichment heavily depends on the quality of antibodies used and may be highly biased. Thus, the use of chemically-induced RT signatures is now considered as the most trusted experimental approach. In addition, the use of chemical reagents allows inclusion of simple "mock-treated" controls, to exclude spontaneous RT arrests, SNPs and other misincorporation-prone sites. Hydrazine is a well-known RNA-specific rea…

Inhibition of the herpes simplex virus-coded thymidine kinase-complex by 9-?-D-arabinofuranosyladenine 5?-monophosphate (ara-AMP) and 9-(2-hydroxyeth…

1984

The thymidine kinase-complex isolated from herpes simplex virus type 1 and type 2 (HSV-1 and HSV-2) is associated with the following enzyme activities: ATP:dThd (dCyd) deoxypyrimidine kinase, ATP:dTMP thymidylate kinase, ADP:dThd- and AMP:dThd5′-phosphotransferase. In kinetic experiments it is shown that ara-AMP inhibits AMP:dThd- and ADP:dThd phosphotransferase activity, while acyclo-GMP impairs ADP:dThd phosphotransferase reaction only; the inhibition was found to be non-compertitive. The functional subunit ATP:dThd kinase was not affected by either compound.

Speciation of chitosan-phosphate and chitosan-nucleotide systems in an NaCl aqueous solution

2010

AbstractThe speciation of chitosan (310 kDa) with organic (adenosine 5’-monophosphate, AMP, and adenosine 5’-triphosphate, ATP), and inorganic phosphorus containing ligands (phosphate and pyrophosphate) was investigated in NaCl aqueous solutions at I = 0.1mol L−1 and T = 25°C. For all the systems, the investigated results obtained gave evidence for the formation of (chitosan)LHi complex species (L = nucleotides, phosphate and pyrophosphate; i = 1 to 4, but for AMP, i = 1 to 3). The stability data of complex species were used to calculate the sequestering ability of chitosan towards phosphorus compounds considered here, expressed as pL50 i.e., – log(total chitosan concentration) necessary to…

Chemical speciation of organic matter in natural waters. Interaction of nucleotide 5′ mono-, di- and triphosphates with major components of seawater

2004

AbstractThe interactions of nucleotide 5’ mono-, di- and triphosphates in a multicomponent ionic medium simulating the macro-composition of seawater (Na+, K+, Ca2+, Mg2+, Cl-, SO42-, Synthetic Sea Water, SSW) have been investigated at different ionic strengths and at T= 25°C. A chemical speciation model, according to which all the internal interactions between the components of the ionic medium are taken into account, was applied to determine the effective formation constants of species in the nucleotide-seawater system. The results were compared to protonation parameters calculated from single electrolyte systems. A simpler model (SSW considered as a single salt BA, with Bz+ and Az-), repr…

Application of a weakly basic dimethylamino-modified silica ion exchanger to the separation of oligonucleotides

1979

Abstract LiChrosorb RP-8, RP-18 and Diol as well as a newly synthesized basic dimethylamino-modified silica ion-exchanger (DMA-silica) were applied for the separation of adenylic acid, cytidylic acid and uridylic acid oligoribonucleotides. On LiChrosorb RP-8 and RP-18, respectively, in aqueous buffered eluents (K 2 HPO 4 - H 3 PO 4 ), the retention of oligonucleotides was increased with decreasing number of nucleotide units in the solute, i.e., with increasing hydrophobic character. The elution behaviour of ologonucleotides on LiChrosorb Diol followed the same order but took place according to a size-exclusion mechanism. The retention of oligonucleotides on DMA-silica is assumed to be based…

Detection of RNA modifications

2010

RNA nucleotide modifications are typically of low abundance and frequently go unnoticed by standard detection methods of molecular biology and cell biology. With a burst of knowledge intruding from such diverse areas as genomics, structural biology, regulation of gene expression and immunology, it becomes increasingly clear that many exciting functions of nucleotide modifications remain to be explored. It follows in turn that the biology of nucleotide modification and editing is a field poised to rapidly gain importance in a variety of fields. The detection and analysis of nucleotide modifications present a clear limitation in this respect. Here, various methods for detection of nucleotide …

Kinetic properties of a nucleoside phosphotransferase of chick embryo

1981

1. A nonspecific nucleoside phosphotransferase (nucleotide : 3'-deoxynucleotide 5'-phosphotransferase, EC 2.7.1.77), purified from chick embryos, catalyzes the transfer of phosphate ester from a nucleotide donor to a nucleoside acceptor. 2. The enzyme exhibits sigmoidal kinetics with respect to nucleoside monophosphate donors, but with respect to nucleoside di- or triphosphate donors and nucleoside acceptors hyperbolic kinetics were obtained. 3. The nucleoside phosphotransferase of chick embryo is unstable to heat and is protected from inactivation by a large number of nucleosides. 4. Nucleoside di- and triphosphates lower both the concentration of nucleoside monophosphates required for hal…