Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.26.9 (ribonuclease)
 6,589 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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