Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:3.1.27.5 (RNase)
17,967 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Insulin-like growth factor I (IGF-I) mRNA was demonstrated in primary cultures of neuronal and glial cells from rat brain. On Northern blots, a rat IGF-I cDNA probe hybridized to RNA species of 7.5, 1.7, and 0.8-1.2 kilobases in total and poly(A)+ RNA from both cell types. Solution hybridization/RNase protection assays were performed using an antisense riboprobe complementary to the 5'-untranslated region as well as part of the coding region of rat IGF-I mRNA. These studies indicated that two of the previously described three possible alternative 5'-untranslated splicing variants (classes A and C) were expressed in neuronal and glial cells, with class C transcripts predominating. Neuronal cells also possessed extremely low levels of class B transcripts. Treatment of neuronal cell cultures with the synthetic glucocorticoid dexamethasone reduced IGF-I mRNA levels by 60%. Glial cell IGF-I mRNA levels were reduced by dexamethasone by up to 40%. These results suggest that glucocorticoid-induced reductions in IGF-I production could occur at the level of transcription and may underlie some of the actions of glucocorticoids in causing growth retardation and inhibition of cell proliferation.
...
PMID:Dexamethasone reduces steady state insulin-like growth factor I messenger ribonucleic acid levels in rat neuronal and glial cells in primary culture. 245 16

Neuronal nitric oxide (NO) synthase, localized to human chromosome 12, uniquely participates in diverse biologic processes; neurotransmission, the regulation of body fluid homeostasis, neuroendocrine physiology, control of smooth muscle motility, sexual function, and myocyte/myoblast biology, among others. Restriction enzyme mapping, subcloning, and DNA sequence analysis of bacteriophage- and yeast artificial chromosome-derived human genomic DNA indicated that the mRNA for neuronal NO synthase is dispersed over a minimum of 160 kilobases of human genomic DNA. Analysis of intron-exon splice junctions predicted that the open reading frame is encoded by 28 exons, with translation initiation and termination in exon 2 and exon 29, respectively. Determination of transcription initiation sites in brain poly(A) RNA with primer extension analysis and RNase protection revealed a major start site 28 nucleotides downstream from a TATA box. Sequence inspection of 5'-flanking regions revealed potential cis-acting DNA elements: AP-2, TEF-1/MCBF, CREB/ATF/c-Fos, NRF-1, Ets, NF-1, and NF-kappa B-like sequences. Diversity appears to represent a major theme apparent upon analysis of human neuronal NO synthase mRNA transcripts. A microsatellite of the dinucleotide variety was detected within the 3'-untranslated region of exon 29. Multiple alleles were evident in normal individuals indicating the existence of allelic mRNA sequence variation. Characterization of variant human neuronal NO synthase cDNAs indicated the existence of casette exon 9/10 and exon 10 deletions as examples of structural mRNA diversity due to alternative splicing. The latter deletion of a 175-nucleotide exon introduces a frame-shift and premature stop codon indicating the potential existence of a novel NH2 terminus protein. In summary, analysis of the human neuronal NO synthase locus reveals a complex genomic organization and mRNA diversity that is both allelic and structural.
...
PMID:Structural organization of the human neuronal nitric oxide synthase gene (NOS1). 752 45

Neurosteroids are steroids that are synthesized de novo in the brain and include some classical (adrenal and gonadal steroids) and some unique brain-specific steroids. Neurosteroids are thought to mediate their action through ion gated channel receptors such as gamma-aminobutyric acid(A) and N-methyl-D-aspartate rather than through classical nuclear steroid hormone receptors. Some enzymes involved in neurosteroidogenesis have been identified as those found in steroidogenic tissues, and some may be unique to the brain. We previously demonstrated that the messenger RNAs (mRNA) for the cholesterol side-chain cleavage enzyme, cytochrome P450scc, and one form of 11 beta-hydroxylase, cytochrome P450c11 beta, are regionally expressed in the adult rat brain. However, cytochrome P450c17, which has 17-hydroxylase and 17,20-lyase activity and is thought to be required for the synthesis of dehydroepiandrosterone, was not detected in any region of the rat brain, even though dehydroepiandrosterone is one of the most abundant neuroactive steroids. We now demonstrate that P450c17 is expressed in the nervous system of the developing rodent embryo. By ribonuclease protection assays, P450c17 mRNA was found in the trunk but not in the head of rat embryos but reverse transcriptase-polymerase chain reaction analysis showed expression of P450c17 mRNA in the head of E15.5 to E19.5 rat embryos. Immunocytochemically detectable P450c17 protein was expressed in the nervous system as early as embryonic day E10.5 in the mouse, mainly in tissue derived from the neural crest. Neuronal cell bodies as well as fibers staining for P450c17 were observed in the central and peripheral nervous systems. The sites of P450c17 expression in the peripheral nervous system suggest it may be involved in a wide variety of sensory-motor functions. In the central nervous system, cell bodies expressing P450c17 are found in the hind brain, in mesencephalic nuclei, and in a region in the location of the locus coeruleus, but in cells distinct from those expressing the dopamine-beta-hydroxylase. Furthermore, its particular location and temporal expression in axons reaching the cortical areas suggest it is a marker for the axonal growth in this region, and that its neurosteroid product may be a signal for targeting cortical axons during embryogenesis.
...
PMID:Steroidogenic enzyme P450c17 is expressed in the embryonic central nervous system. 758 60

RNase protection analysis using p75, trk A, and trk B RNA probes was used to examine mRNA expression in rat tissues, with particular emphasis on the immune system. Every tissue examined, with the exception of postnatal day 0 spleen, expressed p75 mRNA. Trk A mRNA was observed in tissues previously reported to be negative for the trk A receptor, such as kidney, thymus, lymph node, muscle, and lung. Neuronal tissues expressed only the long form of trk A, whereas nonneuronal tissues expressed both trk A forms. Trk B mRNA was expressed by the same tissues as trk A, plus heart and spleen. Neuronal tissues expressed full-length and truncated trk B, whereas nonneuronal tissues only expressed truncated trk B. During development of the thymus p75 mRNA levels increased and trk A mRNA levels decreased. Similarly, for the spleen, p75 mRNA levels increased and those of trk B decreased during development. The expression of p75, trk A and trk B was localized primarily to the stroma of the thymus and spleen, but there was some expression by the splenocytes and thymocytes. The widespread expression of neurotrophin receptors in areas not known to be targets for neurotrophins suggests broader functions for neurotrophins outside of the nervous system.
...
PMID:Widespread neurotrophin receptor expression in the immune system and other nonneuronal rat tissues. 789 Nov 6

Neuronal growth-associated proteins (nGAPs) are markers of neuronal process outgrowth and are associated with both degenerative and sprouting responses in Alzheimer's disease (AD) brain. To study possible involvement of SCG10, an nGAP, in AD, we cloned human SCG10 cDNA and analyzed SCG-10 at mRNA and protein levels in control and AD brains. The deduced amino acid sequence of human SCG10 was 69% identical to stathmin, another nGAP. By in situ hybridization, both SCG10 and stathmin mRNAs were detected in selected neuronal populations in aged human brains. Quantitative analysis by RNase protection revealed that levels of neither SCG10 nor stathmin mRNAs were significantly altered in AD. Using an SCG10-specific antibody, Western blot analysis did not reveal any quantitative changes of SCG10 in AD. However, when the concentration of SCG10 protein was plotted against the number of tangles, a positive correlation was found. SCG10 levels did not correlate with plaque numbers. Furthermore, immunohistochemical study revealed that neuronal SCG10 protein accumulated in the cell bodies in AD-affected regions. Thus, SCG10 compartmentalization and metabolism may be altered in AD possibly due to mechanisms related to tangle formation in this disease.
...
PMID:SCG10, a neuron-specific growth-associated protein in Alzheimer's disease. 862 78

The influence of low or high (10 or 25 mM) K(+)-induced membrane depolarization on the mRNA levels for NMDA receptor subunits was investigated by RNase protection assay in cultured rat cerebellar granule cells. Cells, maintained for 7 days in K25+, a condition that promotes their survival and maturation, express the highest levels of NR-1 and NR-2A mRNA, whereas NR-2B is maximally expressed in cells grown in K10+. Acute changes in medium K+ concentration had a significant effect on the mRNA levels for NMDA receptor subunits. A concomitant reduction of NR-2A mRNA and induction of NR-2B was observed following a 24-h shift of the culture medium from K25+ to K10+. Under these circumstances NR-2C, not detected in basal conditions, became expressed. Neuronal nitric oxide synthase, an enzyme linked to NMDA receptor activation, was also influenced by growth conditions. Its expression, higher under low excitation (K10+), is induced in the shift from K25+ to K10+ and is markedly decreased in the opposite situation. These data indicate that several factors may influence the expression of NMDA receptor subunits and consequently may modulate the function of this receptor complex and its adaptation to acute and chronic changes in neuronal activity.
...
PMID:Acute and chronic changes in K(+)-induced depolarization alter NMDA and nNOS gene expression in cultured cerebellar granule cells. 884 29

Neuronal nicotinic acetylcholine receptors from bovine adrenomedullary chromaffin cells play a primary role in triggering catecholamine secretion. In the present study, their constituent subunits were characterized. In addition to the alpha 3 subunit, which we have previously cloned, the presence of alpha 5 and beta 4 but not of beta 2 subunits was detected by reverse transcription-PCR analysis of mRNA from adrenal medulla. In situ hybridization indicated that alpha 3, alpha 5, and beta 4 subunits are coexpressed in all chromaffin cells. The primary structure of alpha 5 and beta 4 subunits was determined and functional receptors were obtained upon coinjection of subunit cRNAs into Xenopus oocytes. In contrast to other beta 4-containing nicotinic receptors, the ones formed by the bovine beta 4 subunit are insensitive to the agonist cytisine. Finally, we characterized the intergenic region of alpha 3 and alpha 5 subunits, which together with the beta 4 subunit, form a gene cluster in rats and chickens. RNase assays and the existence of overlapping cDNAs indicate that, in the bovine genome, the alpha 3 and alpha 5 genes overlap at their 3' ends. This fact is probably due to inefficient transcription termination, as a result of weak polyadenylation signals.
...
PMID:Neuronal nicotinic acetylcholine receptors on bovine chromaffin cells: cloning, expression, and genomic organization of receptor subunits. 900 33

Fibroblast growth factor-2 (FGF-2) has marked pharmacological neurotrophic effects on lesioned spinal autonomic neurons following target removal of the adrenal medulla, yet expression and axonal transport in autonomic neurons remain to be shown. We show here FGF-2 and FGF receptor type 1 (FGFR1) protein and mRNA expression in preganglionic intermediolateral neurons of the rat thoracic spinal cord. While immunoreactivity of both FGF-2 and FGFR1 co-localize to intermediolateral neurons, mRNA transcripts of FGFR1, but not of FGF-2, are detectable in intermediolateral preparations by RNase protection analysis, suggesting protein translocation in vivo. Unilateral microinjection of 125iodinated FGF-2 into the adrenal medulla (a major target of intermediolateral neurons) results in significant accumulation of specific radioactivity in thoracic spinal cord tissue, including the intermediolateral neurons, and the ipsilateral splanchnic nerve. Emulsion autoradiography demonstrated labelling over ipsilateral intermediolateral neurons only. Neuronal co-localization of FGF-2/FGFR1 protein, differential mRNA expression, specific retrograde axonal transport and the known neurotrophic actions in vivo, strongly suggest unique physiological roles of FGF-2 in the autonomic nervous system.
...
PMID:Localization, differential expression and retrograde axonal transport suggest physiological role of FGF-2 in spinal autonomic neurons of the rat. 905 56

Neuronal precursors and immature cortical neurons actively accumulate Cl- and as a consequence depolarize in response to GABAA receptor activation. With maturity, intracellular Cl- decreases resulting in a shift towards GABAA inhibition. These observations suggest that changes in expression of cation-Cl- cotransporters may have a significant role in the ontogeny of neuronal Cl- homeostasis. Using ribonuclease protection analysis and in situ hybridization we examined the developmental expression of all presently known members of the cation-Cl- cotransporter gene family in rat brain. Of the inwardly directed cotransporters, NKCC-1, NKCC-2, and NCC-1, only NKCC-1 was detected at significant levels in brain. NKCC-1 was expressed in neurons, appearing first in cortical plate but not in ventricular or subventricular zone. Expression levels peaked by the third postnatal week and were maintained into adulthood. The outwardly directed cotransporters, KCC-1 and KCC-2, demonstrated significantly different levels and time courses of expression. KCC-1 was expressed prenatally at very low levels which increased little over the course of development. In contrast, KCC-2 expression appeared perinatally and increased dramatically after the first week of postnatal life. Differential changes in expression of this gene family occurred during periods of critical shifts in chloride homeostasis and GABA response suggestive of a role in these processes. Furthermore the absence of expression of known inwardly directed cotransporters in Cl- accumulating neuroepithelia and lack of evidence for glial expression suggests that as yet unidentified members of this gene family may be involved in chloride homeostasis in immature neuronal precursors and neuroglia.
...
PMID:Ontogeny of cation-Cl- cotransporter expression in rat neocortex. 972 31

Neuronal nicotinic acetylcholine receptor (nAChR) subunit genes compose a family of genes. The major isoform of nAChR in the brain is made up of the alpha4 and beta2 subunits and possesses a high affinity for nicotine. To investigate the mechanisms of the regulation of the nAChR alpha4 gene expression in mouse, its genomic DNA was cloned and characterized. The transcription initiation site was mapped by primer extension and RNase protection experiments and localized at about 254 bp upstream of the translation initiation site. The 5' flanking region of this gene did not have typical TATA box but GC-rich sequences were found around the initiation site. Methylation analysis of this region revealed that genomic DNAs from liver and muscle are partially methylated, whereas little methylation was observed in genomic DNA from brain. To characterize the cis-acting elements driving cell-specific expression of the alpha4 subunit gene, we produced lines of transgenic mice which carry a series of fragments of the alpha4 gene fused with bacterial lacZ as a reporter gene. An 11.5-kb DNA fragment containing 9 kb of the region upstream of the transcription initiation site and the first intron was found to confer an expression pattern which coincides rather well with the endogenous gene expression pattern at early embryonic stages, suggesting that the elements necessary for the onset of alpha4 gene expression are located in this region. A DNA fragment containing the 1.8-kb upstream sequence and the first intron drove expression of lacZ in a limited subset of alpha4 expressing cells, whereas the 1.8-kb upstream sequence alone did not elicit any significant expression. These results show that both upstream and intronic sequences are important for cell-specific expression of the nAChR alpha4 gene.
...
PMID:Promoter analysis of the neuronal nicotinic acetylcholine receptor alpha4 gene: methylation and expression of the transgene. 974 53


1 2 Next >>

---