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 highly conserved, intracellular calcium binding protein calmodulin is present in all cells at all times. In addition to this constitutive level, the amount of calmodulin is highly regulated according to the tissue or stage of development. Since there are only a few genes or a single gene for this protein in most species, intricate regulatory elements may be necessary to effect its complex regulation. This report adds new information concerning the gene structure and outlines the developmental and spatial regulation of Drosophila melanogaster calmodulin transcripts. The gene contains five exons, including a 49 bp exon in the 5' untranslated region, and spans over 16 kb. Homologues to this small, 5' noncoding exon have not been found in other calmodulin genes. The combined level of the transcripts is developmentally regulated, and the relative amounts of the two transcript size classes (1.65 kb and 1.9 kb) are differentially regulated during development. Primer extension experiments and RNase protection mapping show that both size classes of Drosophila calmodulin transcripts initiate at the same site but undergo alternative termination within the final exon. The spatial distribution of calmodulin transcripts was examined by in situ hybridization to sections of adults and to developmentally staged whole mount embryos. Calmodulin transcripts are evenly distributed early in embryogenesis. In later stages of embryogenesis, higher levels accumulate in the developing nerve cord and other tissues. Elevated levels of calmodulin transcripts are seen quite distinctly in the adult neural tissues and in the photoreceptor region of the compound eye.
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PMID:Developmental expression of the Drosophila melanogaster calmodulin gene. 128 Jan 54

The seco-steroid hormone 1,25-dihydroxyvitamin D3 is known to induce the expression of a calcium binding protein termed calbindin-D28K in a variety of target tissues. In order to comprehend the mechanism of induction we have cloned and sequenced the chicken calbindin-D28K gene. The gene spans some 18.5 kilobases (kb) of chromosomal DNA from the putative Cap site to the polyadenylation site of the 2.8 kb mRNA. It is split into 11 coding exons by 10 intervening sequences. The promoter region of this gene is markedly G + C-rich (60-80%) extending from -225 to +400. Within this region we find 70 CpG dinucleotides, four G-C boxes, and numerous known promoter regulatory signals. These putative regulatory signals include a TATA box (ATAAATA) at -30 and a CAT box (CCAAT) at -326. Ten additional variant CAT boxes are found in the upstream promoter region (-218 to -770) of this gene. Furthermore we have identified a glucocorticoid-like responsive element at -410 (TCTACACACTGTTCC) and this element overlaps a metal responsive element (TGCACTC) and a variant CAT box (CCAAAT) and juxtaposes an enhancer-like core element (AAATGGT) on its 3'-side. In addition, the calbindin-D28K promoter is composed of a variety of simple repeated sequences, some of which are components of putative regulatory signals. All splice junctions were found to conform to the GT-AG rule. A consensus sequence of the 5'-splice junction reads AG/GTAAG-TTATA. A consensus sequence of the 3'-splice site consists of two elements: a pyrimidine track (mainly T) followed by ACAG/G-T. A two-dimensional model of calbindin-D28K was constructed which projects the existence of 6 alpha-helix-loop-alpha-helix regions characteristic of calcium binding domains. The 3'-end of the gene consists of a single large (2039 base pair) uninterrupted exon, an organizational feature common to other members of the calcium binding protein gene family which include calmodulin, parvalbumin, Spec I, myosin light chains, etc. Another feature common to the gene family is the presence of the repeated sequence ATTT or TTTA located in the 3'-untranslated exons. These simple repeat sequences could be involved in regulating mRNA degradation by serving as a ribonuclease recognition signal.
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PMID:Molecular structure of the chicken vitamin D-induced calbindin-D28K gene reveals eleven exons, six Ca2+-binding domains, and numerous promoter regulatory elements. 296 15

Calretinin is an EF-hand calcium binding protein found predominantly in discrete sets of neurons in the central system, and in the sex hormone producing cells of the gonads. Calretinin mRNA levels were measured in discrete brain areas from vehicle and corticosterone treated rats (subcutaneous injections of 0, 0.1, 1, or 10 mg, 7 days) using a micropunch ribonuclease protection assay. Treatment with high dose corticosterone (10 mg) caused a 93% decrease in calretinin mRNA levels in the hypothalamic paraventricular nucleus compared to controls. Two other brain regions, the medial amygdaloid nucleus and the nucleus reuniens, demonstrated an approximately 40% decrease in calretinin mRNA following high dose corticosterone. In separate experiments, adrenalectomy and diurnal corticosterone variations had no effect on calretinin mRNA in the brain areas examined. In the testes, corticosterone treatment decreased calretinin protein in a dose dependent fashion (to 81%, 68%, and 39% of controls at doses of 10, 1, and 0.1 mg/day, respectively). Low dose corticosterone treatments decreased testicular but not neuronal calretinin mRNA, whereas high dose corticosterone reduced calretinin mRNA in testes and several discrete brain areas. This suggests that corticosterone's effects on brain calretinin may be due to its pathological effects, e.g. energy depletion of brain cells or interference with the normal support functions of glia.
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PMID:Corticosterone effects on rat calretinin mRNA in discrete brain nuclei and the testes. 770 81

Calretinin, a highly evolutionarily conserved E-F hand calcium binding protein, is expressed predominantly in neurons, with a few exceptions. The function of calretinin is not known. We demonstrate the expression of calretinin mRNA and protein in rat testes. Immunocytochemistry and in situ hybridization reveal that calretinin expression in testis is localized to the interstitial Leydig cells. Western blot and ribonuclease protection analyses show that calretinin protein and mRNA in testis is the same as that expressed in brain. It is suggested that calretinin may play a role in the production of testosterone.
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PMID:Calretinin is expressed in the Leydig cells of rat testis. 791 40

A microdissection technique for quantitation of neurochemicals in discrete brain nuclei has been applied to quantitative measurement of mRNA. The method permits quantitation of low abundance mRNA from submilligram amounts of tissue (10-500 micrograms protein). Discrete nuclei and other regions of the brain are solubilized in concentrated guanidine thiocyanate solution, mRNA is directly hybridized with riboprobes, and detected with a ribonuclease protection assay. This method eliminates the necessity for RNA isolation from solid tissue. No assumptions regarding RNA recovery are necessary since tissue specimens are solubilized, hybridized and treated with ribonuclease in a single tube. We have determined the mRNA levels of calretinin, a predominantly neuron-specific calcium binding protein in microdissected nuclei and other regions of rat brain. For interassay comparison, measurement of sample protein and beta-actin mRNA permits normalization and quantitation in terms of these internal controls. The quantity of calretinin mRNA ranged from 281 +/- 35 fg/micrograms protein in the thalamic paraventricular nucleus to 2.3 +/- 0.5 fg/micrograms protein for the cerebral cortex. The calretinin/beta-actin ratios ranged from 79.9 +/- 9.3% to 1.3 +/- 0.1%, respectively. The combination of microdissection techniques with a lysate RNase protection assay: (1) establishes this technique as quantitative for detection of high and low abundance mRNAs from microdissected brain specimens; (2) bypasses the inefficiencies and uncertainties associated with isolating RNA; and (3) enables large numbers of determinations from discrete brain nuclei to be analyzed in 2 to 3 days.
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PMID:Quantitative measurement of calretinin and beta-actin mRNA [correction of mRNAIN] in rat brain micropunches without prior isolation of RNA. 830 61

Temperate cereals, such as wheat (Triticum spp.) and barley (Hordeum vulgare), respond to prolonged cold by becoming more tolerant of freezing (cold acclimation) and by becoming competent to flower (vernalization). These responses occur concomitantly during winter, but vernalization continues to influence development during spring. Previous studies identified VERNALIZATION1 (VRN1) as a master regulator of the vernalization response in cereals. The extent to which other genes contribute to this process is unclear. In this study the Barley1 Affymetrix chip was used to assay gene expression in barley seedlings during short or prolonged cold treatment. Gene expression was also assayed in the leaves of plants after prolonged cold treatment, in order to identify genes that show lasting responses to prolonged cold, which might contribute to vernalization-induced flowering. Many genes showed altered expression in response to short or prolonged cold treatment, but these responses differed markedly. A limited number of genes showed lasting responses to prolonged cold treatment. These include genes known to be regulated by vernalization, such as VRN1 and ODDSOC2, and also contigs encoding a calcium binding protein, 23-KD jasmonate induced proteins, an RNase S-like protein, a PR17d secretory protein and a serine acetyltransferase. Some contigs that were up-regulated by short term cold also showed lasting changes in expression after prolonged cold treatment. These include COLD REGULATED 14B (COR14B) and the barley homologue of WHEAT COLD SPECIFIC 19 (WSC19), which were expressed at elevated levels after prolonged cold. Conversely, two C-REPEAT BINDING FACTOR (CBF) genes showed reduced expression after prolonged cold. Overall, these data show that a limited number of barley genes exhibit lasting changes in expression after prolonged cold treatment, highlighting the central role of VRN1 in the vernalization response in cereals.
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PMID:Transcriptome analysis of the vernalization response in barley (Hordeum vulgare) seedlings. 2140 15