Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.27.5 (RNase)
 17,967 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A compact region in the human class III major histocompatibility locus contains the human genes for the fourth component of human complement (C4) and steroid 21-hydroxylase (P450c21) in one transcriptional orientation, while the gene for the extracellular matrix protein tenascin-X (TN-X) overlaps the last exon of P450c21 on the opposite strand of DNA in the opposite transcriptional orientation. This complex locus is duplicated into A and B loci, so that the organization is 5'-C4A-21A-XA-C4B-21B-XB-3'. Although this duplication event truncated the 65-kb X(B) gene to a 4.5-kb XA gene, the XA gene is transcriptionally active in the adrenal cortex. To examine the basis of the tissue-specific expression of XA and C4B, we cloned the 1763-bp region that lies between the cap sites for XA and C4B and analyzed its promoter activity in both the XA and the C4 orientations. Powerful, liver-specific sequences lie within the first 75 to 138 bp from the C4B cap site, and weaker elements lie within 128 bp of the XA cap site that function in both liver and adrenal cells. Because these 128 bp upstream from the XA cap site are perfectly preserved in the XB gene encoding TN-X, we sought to determine whether a transcript similar to XA arises within the XB gene. RNase protection assays, cDNA cloning, and RT/PCR show that adrenal cells contain a novel transcript, termed short XB (XB-S), which has the same open reading frame as TN-X.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Sequences promoting the transcription of the human XA gene overlapping P450c21A correctly predict the presence of a novel, adrenal-specific, truncated form of tenascin-X. 853 23

Increased extraglandular aromatization has been reported as the cause of familial gynecomastia. We studied a kindred with aromatase excess inherited in an autosomal dominant manner, in which affected males had heterosexual precocity and/or gynecomastia, and affected females had isosexual precocity and/or macromastia. The propositus was a 9-yr-old boy with gynecomastia. His 7.5-yr-old sister had precocious puberty, and their father and paternal grandmother had peripubertal gynecomastia and macromastia, respectively. Serum concentrations of gonadal and adrenal steroid hormones were determined before and after the administration of corticotropin and/or hCG. Aromatase activity was determined by [3H]delta4-androstenedione to [3H]estrone conversion by cultured skin fibroblasts and/or Epstein-Barr virus-transformed lymphocytes and was detected by immunohistochemistry and/or Western analysis. Linkage was examined with a polymorphism of the aromatase (P450arom) gene. The P450arom messenger ribonucleic acid was analyzed by rapid amplification of complementary DNA (cDNA) ends, ribonuclease protection assay, and RT-PCR. hCG testing demonstrated a high rate of conversion of delta4-androstenedione to estrone and of testosterone to estradiol in the propositus and his father. Treatment of the propositus and his sister was initiated with an aromatase inhibitor (testolactone) and a GnRH analog, which successfully delayed skeletal and pubertal development in both children. Markedly increased aromatase activity was found in the patients' fibroblasts and Epstein-Barr virus-transformed lymphocytes. The P450arom polymorphism segregated with the disease in the family. A new 5'-splice variant was present in the patients' P450arom messenger ribonucleic acid, thus identifying yet another first exon of this gene, which appears to be aberrantly expressed in this family. In conclusion, a family with the aromatase excess syndrome is described, in which the condition was inherited in an autosomal dominant manner, led to feminizing manifestations in both sexes, and was associated with the aberrant utilization of a novel transcript of the P450arom gene.
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PMID:The aromatase excess syndrome is associated with feminization of both sexes and autosomal dominant transmission of aberrant P450 aromatase gene transcription. 954 66

RXR beta is predominantly involved in retinoid responses in neuroblastoma cells, in particular the N-type SH SY 5Y cells and the S-type SH S EP cells, both derivatives of a mixed phenotype neuroblastoma cell line. The aim of this study was to identify RXR beta isoforms expressed in neuroblastoma cells and to characterise a putative novel RXR beta transcript. RXR beta 1 and RXR beta 2 were expressed in these neuroblastoma cells. An isoform with an insertion into the ligand binding domain, RXR beta(SLSR) (referred to in previous studies as RXR beta 3), was expressed at a similar level to RXR beta. A novel RXR beta transcript was identified by RNase protection assays and was at least as abundant as the expected RXR beta transcript and expressed in other cell types. Evidence suggests that this novel transcript was transcribed from an internal promoter between exons 5 and 6, contained a retained intron (intron 6) and was alternatively spliced with and without the SLSR insertion. These data show that the pattern of RXR beta expression is complex. The relative abundance of the novel RXR beta transcript suggests that it may be an important aspect of RXR beta function or regulation in a range of cell types.
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PMID:RXR beta isoforms in neuroblastoma cells and evidence for a novel 3'-end transcript. 1159 67

Previously, we reported the presence in mouse cells of a mitochondrial RNA which contains an inverted repeat (IR) of 121 nucleotides (nt) covalently linked to the 5' end of the mitochondrial 16S RNA (16S mtrRNA). Here, we report the structure of an equivalent transcript of 2374 nt which is over-expressed in human proliferating cells but not in resting cells. The transcript contains a hairpin structure comprising an IR of 815 nt linked to the 5' end of the 16S mtrRNA and forming a long double-stranded structure or stem and a loop of 40 nt. The stem is resistant to RNase A and can be detected and isolated after digestion with the enzyme. This novel transcript is a non-coding RNA (ncRNA) and several evidences suggest that the transcript is synthesized in mitochondria. The expression of this transcript can be induced in resting lymphocytes stimulated with phytohaemagglutinin (PHA). Moreover, aphidicolin treatment of DU145 cells reversibly blocks proliferation and expression of the transcript. If the drug is removed, the cells re-assume proliferation and over-express the ncmtRNA. These results suggest that the expression of the ncmtRNA correlates with the replicative state of the cell and it may play a role in cell proliferation.
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PMID:Expression of a novel non-coding mitochondrial RNA in human proliferating cells. 1796 5

The AML1 gene is an essential transcription factor regulating the differentiation of hematopoietic stem cells into mature blood cells. Though at least 12 different alternatively spliced AML1 mRNAs are generated, three splice variants (AML1a, AML1b and AML1c) have been characterized. Here, using the reverse transcription-polymerase chain reaction with outward-facing primers, we identified a novel non-polyadenylated transcript from the AML1 gene, with exons 5 and 6 scrambled. The novel transcript resisted RNase R digestion, indicating it is a circular RNA structure that may originate from products of mRNA alternative splicing. The expression of the novel transcript in different cells or cell lines of human and a number of other species matched those of the canonical transcripts. The discovery provides additional evidence that circular RNA could stably exist in vivo in human, and may also help to understand the mechanism of the regulation of the AML1 gene transcription.
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PMID:Identification of a novel circularized transcript of the AML1 gene. 2352 60