Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.26.4 (RNase H)
 2,751 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Proinsulin mRNA was analyzed by RNA blot hybridization from four insulin-expressing tissues of the rat, including adult and fetal pancreas, yolk sac, and an insulinoma cell line (RIN 5F). The proinsulin mRNA transcripts from the insulinoma cell line and fetal pancreatic tissue were estimated to be, respectively, 100 and 50 bases larger than the transcript from adult pancreas. Yolk sac proinsulin mRNA comigrated with the fetal transcript. While glucose is an important regulator of proinsulin mRNA in the adult, there is a marked increase in the concentrations of proinsulin mRNA and insulin in the developing rat, although plasma glucose levels are quite low. Expression of proinsulin mRNA independent of glucose levels is also found in insulinoma tissue. In addition, there is a second TATA sequence upstream of the putative start site in rat insulin II gene, and the transcription initiation site(s) has not been mapped in all of these tissues. These observations suggested that alternative transcription initiation sites may place the genes under different promoter control during development. To map the 5' end of the gene, primer extension was performed using a synthetic oligonucleotide primer complementary to the first 20 bases of the coding portion of the rat insulin I gene. The extended products of the proinsulin mRNAs from adult insulinoma cell line and fetal pancreas were identical and consistent in size with those predicted if transcription occurs at the putative start site. The 3' ends of the proinsulin mRNA transcripts were evaluated by ribonuclease H digestion, and it was shown that the noted size differences could be accounted for by different lengths of 3'-polyadenylation. Northern blot analysis of proinsulin mRNA from animals treated under conditions where mRNA varied from low to high levels failed to show any modulation of polyadenylation. The role of polyadenylation of proinsulin mRNA in the physiological regulation of insulin biosynthesis, if any, is currently unknown.
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PMID:Identical transcription initiation sites for proinsulin messenger ribonucleic acid in three insulin-expressing tissues. 300 26

A filamentous bulking of a methanogenic granular sludge caused by uncultured filamentous bacteria of the candidate phylum KSB3 in an upflow anaerobic sludge blanket (UASB) system has been reported. To characterize the physiological traits of the filaments, a polyphasic approach consisting of rRNA-based activity monitoring of the KSB3 filaments using the RNase H method and substrate uptake profiling using microautoradiography combined with fluorescence in situ hybridization (MAR-FISH) was conducted. On the basis of rRNA-based activity, the monitoring of a full-scale UASB reactor operated continuously revealed that KSB3 cells became active and predominant (up to 54% of the total 16S rRNA) in the sludge when the carbohydrate loading to the system increased. Batch experiments with a short incubation of the sludge with maltose, glucose, fructose, and maltotriose at relatively low concentrations (approximately 0.1 mM) in the presence of yeast extract also showed an increase in KSB3 rRNA levels under anaerobic conditions. MAR-FISH confirmed that the KSB3 cells took up radioisotopic carbons from [(14)C]maltose and [(14)C]glucose under the same incubation conditions in the batch experiments. These results suggest that one of the important ecophysiological characteristics of KSB3 cells in the sludge is carbohydrate degradation in wastewater and that high carbohydrate loadings may trigger an outbreak of KSB3 bacteria, causing sludge bulking in UASB systems.
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PMID:Ecophysiology of uncultured filamentous anaerobes belonging to the phylum KSB3 that cause bulking in methanogenic granular sludge. 2125 8

Antisense oligodeoxynucleotides (ODNs) are short synthetic DNA polymers complementary to a target RNA sequence. They are commonly designed to halt a biological event, such as translation or splicing. ODNs are potentially useful therapeutic agents for the treatment of different human diseases. Carbohydrate-ODN conjugates have been reported to improve the cell-specific delivery of ODNs through receptor mediated endocytosis. We tested the anti-HIV activity and biochemical properties of the 5'-end glucose-conjugated GEM 91 ODN targeting the initiation codon of the gag gene of HIV-1 RNA in cell-based assays. The conjugation of a glucose residue significantly reduces the immunostimulatory effect without diminishing its potent anti-HIV-1 activity. No significant effects were observed in either ODN stability in serum, in vitro degradation of antisense DNA-RNA hybrids by RNase H, cell toxicity, cellular uptake and ability to interfere with genomic HIV-1 dimerisation.
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PMID:Glucose conjugation of anti-HIV-1 oligonucleotides containing unmethylated CpG motifs reduces their immunostimulatory activity. 2568 51