Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.27.1 (RNase)
 16,360 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The activity of guanylate cyclase and that of its inhibitor present in E. coli extract, have been separated through a linear KCl gradient on DEAE-cellulose column. The activity of the inhibitor is lost after ribonuclease treatment, whereas is strengthened by addition of poly (C). Other types of RNA synthetic homopolymers do not affect the inhibitor's activity. Chromatographic analysis of the products of guanylate cyclase measured in the presence of FI and FI plus poly (C), indicated that the inhibitor has a poly (C) dependent GTPase activity.
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PMID:[Guanyl cyclase in Escherichia coli. II. Identification and characteristics on the enzyme inhibitor]. 3 98

Dynamin, a microtubule-activated GTPase, has recently been identified as the product of the shibire gene in Drosophila. shi(ts) mutants are defective in synaptic vesicle recycling, which leads to rapid and reversible temperature-sensitive paralysis. In the present study, results from RNase protection assays and analysis of cDNA clones define a complex pattern of developmental- and tissue-specific alternative splicing at two sites within the coding region. This analysis is also supported by western blot analysis with two polyclonal antibodies. In situ hybridization data revealed a high concentration of shi transcripts in the central and peripheral nervous system throughout neuronal development. Other than the nervous system, shi transcripts are also expressed at a high level in early embryos, larval imaginal discs, and male and female gonads. These data provide a basis for interpreting the wide range of phenotypic effects of shi mutations in terms of the putative membrane-sorting properties of dynamin and for further functional study of different dynamin isoforms.
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PMID:Developmental stage- and tissue-specific expression of shibire, a Drosophila gene involved in endocytosis. 147 60

The 23 S RNA genes representative of each of the main archaebacterial subkingdoms, Desulfurococcus mobilis an extreme thermophile, Halococcus morrhuae an extreme halophile and Methanobacterium thermoautotrophicum a thermophilic methanogen, were cloned and sequenced. The inferred RNA sequences were aligned with all the available 23 S-like RNAs of other archaebacteria, eubacteria/chloroplasts and the cytoplasm of eukaryotes. Universal secondary structural models containing six major structural domains were refined, and extended, using the sequence comparison approach. Much of the present structure was confirmed but six new helices were added, including one that also exists in the eukaryotic 5.8 S RNA, and extensions were made to several existing helices. The data throw doubt on whether the 5' and 3' ends of the 23 S RNA interact, since no stable helix can form in either the extreme thermophile or the methanogen RNA. A few secondary structural features, specific to the archaebacterial RNAs were identified; two of these were supported by a comparison of the archaebacterial RNA sequences, and experimentally, using chemical and ribonuclease probes. Seven tertiary structural interactions, common to all 23 S-like RNAs, were predicted within unpaired regions of the secondary structural model on the basis of co-variation of nucleotide pairs; two lie in the region of the 23 S RNA corresponding to 5.8 S RNA but they are not conserved in the latter. The flanking sequences of each of the RNAs could base-pair to form long RNA processing stems. They were not conserved in sequence but each exhibited a secondary structural feature that is common to all the archaebacterial stems for both 16 S and 23 S RNAs and constitutes a processing site. Kingdom-specific nucleotides have been identified that are associated with antibiotic binding sites at functional centres in 23 S-like RNAs: in the peptidyl transferase centre (erythromycin-domain V) the archaebacterial RNAs classify with the eukaryotic RNAs; at the elongation factor-dependent GTPase centre (thiostrepton-domain II) they fall with the eubacteria, and at the putative amino acyl tRNA site (alpha-sarcin-domain VI) they resemble eukaryotes. Two of the proposed tertiary interactions offer a structural explanation for how functional coupling of domains II and V occurs at the peptidyl transferase centre. Phylogenetic trees were constructed for the archaebacterial kingdom, and for the other two kingdoms, on the basis of the aligned 23 S-like RNA sequences.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Evolutionary relationships amongst archaebacteria. A comparative study of 23 S ribosomal RNAs of a sulphur-dependent extreme thermophile, an extreme halophile and a thermophilic methanogen. 311 61

A new RNase activity, tentatively named RNase V, was found in cell-free extracts of E. coli. This activity requires ribosomes, G and T factors, tRNA, K(+) or NH(4) (+), Mg(2+), GTP, and a sulfhydryl compound to degrade poly U, poly A, T4 phage mRNA, or E. coli mRNA. RNase V is specific for mRNA; it does not attack ribosomal RNA. It is inhibited by antibiotics that decrease breakdown of mRNA in vivo, such as chloramphenicol and streptomycin, and by such agents as 5'-beta, gamma-methylene-guanosine triphosphate, and fusidic acid, which inhibit ribosome-dependent GTPase and translocation of ribosomes along mRNA. The evidence suggests that RNase V is either an integral part of the ribosome or is tightly associated with it, and that it selectively degrades mRNA in intact cells.
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PMID:Ribonuclease V of escherichia coli. I. Dependence on ribosomes and translocation. 490 7

Site-specific anti-RNA antibodies were sought in 120 sera of patients with autoimmune diseases by ribonuclease-protection assay using six fragments covering 28S ribosomal RNA (rRNA) as antigens. Fifteen of 90 sera from patients with systemic lupus erythematosus (SLE), but none of 30 sera of the other autoimmune diseases, provided a 60 nucleotide fragment within a region termed the 'GTPase domain' of 28S rRNA. These sera had potency to precipitate 0.42-69.3 nmol of the RNA domain per ml serum, which was higher than 15 control sera of healthy donors. No other specific antigenic site was detected in 28S rRNA under conditions used. All of the 15 sera having this anti-RNA antibody showed reactivity to ribosomal P proteins (anti-P), and two of them contained an additional antibody to ribosomal protein L12. These results suggested a strong association of the production of these three antibodies. Since P and L12 proteins form a stable complex with the GTPase domain, this serological association may result from an immune response to epitopes clustered on a single RNA-protein complex domain in ribosomes.
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PMID:Serological association of lupus autoantibodies to a limited functional domain of 28S ribosomal RNA and to the ribosomal proteins bound to the domain. 792 81

Neurofibromatosis type 1 (NF-1) is among the most common inherited diseases affecting cells of the central and peripheral nervous systems. A region of the NF-1 gene is similar in sequence to the ras-GTPase activator protein (ras-GAP), and investigations have confirmed that the NF-1 gene product (now known as neurofibromin) stimulates ras-GTPase activity in vitro and in vivo. Neurofibromin modulates the ability of ras proteins to regulate cellular proliferation and/or differentiation, suggesting a possible role in normal development. An alternative form of the neurofibromin transcript with an additional 63-bp exon inserted in the GAP-related domain (GRD) has been described recently. To determine whether differential expression of the two forms of neurofibromin GRD mRNA plays a role in embryonic development, we have isolated and characterized the corresponding chicken cDNA. The predicted amino acid sequence for the inserted exon is identical between chick and human, as are the exon-intron boundaries. RNase protection and RNA-polymerase chain reaction analyses demonstrate that most tissues express predominantly type II mRNA (which contains the insert) throughout embryonic development. In contrast, whereas type II is the major form in the brain early in development, expression of the type I transcript (without the insert) in this tissue increases dramatically at later times. Analysis of primary cultures derived from chick embryo brain indicates that the type I mRNA is enriched in neurons.
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PMID:Regulated expression of the neurofibromin type I transcript in the developing chicken brain. 824 61

Ras associated with diabetes (Rad), a new ras-related GTPase, was recently identified by subtractive cloning as an mRNA in skeletal muscle that is overexpressed in NIDDM. To better understand its metabolic significance, we measured skeletal muscle Rad expression in well-characterized insulin sensitive (IS) and insulin resistant (IR) subjects with normal glucose tolerance and in untreated NIDDM patients. We found no differences in expression of Rad mRNA levels among IS, IR, and NIDDM groups using a ribonuclease protection assay (0.22 +/- 0.06, 0.13 +/- 0.01, and 0.16 +/- 0.02 relative units, respectively; NS) and no differences in Rad protein expression using a specific anti-peptide Rad antibody (1.05 +/- 0.18, 1.14 +/- 0.08, and 1.08 +/- 0.21 units/mg protein, respectively; NS). However, Rad protein levels were positively correlated with BMI (r = 0.43, P = 0.03) and percentage body fat (r = 0.55, P < 0.005), two independent measures of obesity, and negatively correlated with resting metabolic rate (r = 0.49, P = 0.01). In multiple regression analyses, percentage body fat and resting metabolic rate independently accounted for 30 and 10% of individual variability in muscle Rad protein expression. In conclusion, Rad expression in skeletal muscle is not altered as a function of insulin resistance or NIDDM in humans. However, these data, for the first time, implicate a role for Rad in regulating body composition and energy expenditure and provide a framework for studies designed to elucidate Rad's cellular functions.
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PMID:Muscle Rad expression and human metabolism: potential role of the novel Ras-related GTPase in energy expenditure and body composition. 903 1

Aripiprazole, a quinolinone derivative, is a new dopaminergic agent which has been recently developed and demonstrated to be clinically useful as an antipsychotic drug with reduced extrapyramidal motor side effects. Here, we found that aripiprazole competed [3H]spiperone binding with a 100-fold higher affinity than [3H]SCH23390 binding, and inhibited the quinpirole-induced facilitation of high-affinity GTPase activity in rat striatal membranes. The effects of chronic administration of aripiprazole and haloperidol on dopamine D2 receptor binding and mRNA level in rat striata were examined by a [3H]spiperone binding assay and a ribonuclease protection assay. Haloperidol induced a significant rise in Bmax of [3H]spiperone binding at 1 mg/kg and in the level of dopamine D2L receptor mRNA at 4 mg/kg. A high dose of aripiprazole (100 mg/kg) only tended to increase the Bmax of [3H]spiperone binding non-significantly, and had no effect on the level of dopamine D2L receptor mRNA. These results indicated that aripiprazole had an antagonistic activity to dopamine D2 receptors with a high affinity, but that the potency of aripiprazole to up-regulate dopamine D2 receptors in the striatum was much smaller than that of haloperidol. This small up-regulation may be related to the ability to aripiprazole to act without side effects including tardive dyskinesia.
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PMID:Aripiprazole, a novel antipsychotic drug, inhibits quinpirole-evoked GTPase activity but does not up-regulate dopamine D2 receptor following repeated treatment in the rat striatum. 908 92

In Scrobicularia plana testis, a nuclear acid phosphatase (ACPase) activity was detected in mid and late spermatids with the improved Gomori-chloride procedure. Lead deposits were first observed in mid spermatids at focal points over condensed chromatin strands, increasing in density as chromatin further condensated. In late spermiogenesis, lead deposits became concentrated between chromatin aggregates, and after total DNA compaction were transfered to the nuclear periphery and then shed into the cytoplasm. The specificity of the nuclear ACPase was tested against different pH values (3.9, 7.2, 7.8, 9.0), substrates (TPP, IDP, TMP, p-NCS, ATP, GTP, AMP, ADP, AMP-PNP) and inhibitors (NaF, levamisole, Zn, vanadate, theophylline). To further specify the nature of this nuclear ACPase, other enzymes were comparatively studied at their optimal pH values and at pH 5.0: nucleoside-diphosphatase, thiamin-pyrophosphatase, inorganic trimetaphosphatase, lysosomal arylsulfatases A and B, ATPase, GTPase, 5'-nucleotidase, adenylate kinase, and adenylate cyclase. Several other controls were introduced to exclude artefactual deposits induced by lead ions and tissue molecules. The results showed that the enzyme has an optimal pH at 5.0, a high specific affinity for beta-GP, and is inhibited by NaF, which suggests that it behaves as a type B-ACPase, and all controls demonstrated the specificity of the enzymic activity. Because lead deposits were specifically and temporally associated with spermatid chromatin condensation, when DNA and RNA synthesis, histones, phosphoproteins and RNA molecules strongly decrease, it is possible to suggest that the nuclear ACPase could be associated with DNA processing during chromatin compaction or involved in the hydrolysis of 2' and 3' nucleotides resulting from nuclear RNase action during RNA degradation.
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PMID:Chromatin condensation during Scrobicularia plana spermiogenesis: a controlled and comparative enzymatic ultracytochemical study. 1079 22

Era, an essential GTPase, appears to play an important role in the regulation of the cell cycle and protein synthesis of bacteria and mycoplasmas. In this study, native Era, His-tagged Era (His-Era) and glutathione S-transferase (GST)-fusion Era (GST-Era) proteins from Escherichia coli were expressed and purified. It was shown that the GST-Era and His-Era proteins purified by 1-step affinity column chromatographic methods were associated with RNA and exhibited a higher GTPase activity. However, the native Era protein purified by a 3-step column chromatographic method had a much lower GTPase activity and was not associated with RNA which had been removed during purification. Purified GST-Era protein was shown to be present as a high- and a low-molecular-mass forms. The high-molecular-mass form of GST-Era was associated with RNA and exhibited a much higher GTPase activity. Removal of the RNA associated with GST-Era resulted in a significant reduction in the GTPase activity. The RNA associated with GST-Era was shown to be primarily 16S rRNA. A purified native Era protein preparation, when mixed with total cellular RNA, was found to bind to some of the RNA. The native Era protein isolated directly from the cells of a wild-type E. coli strain was also present as a high-molecular-mass form complexed with RNA and RNase treatment converted the high-molecular-mass form into a 32 kDa low-molecular-mass form, a monomer of Era. Furthermore, a C-terminally truncated Era protein, when expressed in E. coli, did not bind RNA. Finally, the GTPase activity of the Era protein free of RNA, but not the Era protein associated with the RNA, was stimulated by acetate and 3-phosphoglycerate. These carbohydrates, however, failed to activate the GTPase activity of the C-terminally truncated Era protein. Thus, the results of this study establish that the C-terminus of Era is essential for the RNA-binding activity and that the RNA and carbohydrates modulate the GTPase activity of Era possibly through a similar mechanism.
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PMID:Era GTPase of Escherichia coli: binding to 16S rRNA and modulation of GTPase activity by RNA and carbohydrates. 1083 34


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