Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027819 (neuroblastoma)
 27,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

By screening a human fetal brain cDNA expression library using a monoclonal antiphosphotyrosine antibody and by 5' RACE procedures, we have isolated overlapping cDNAs encoding a receptor-type tyrosine kinase belonging to the EPH family, DRT (Developmentally Regulated EPH-related Tyrosine kinase gene). The DRT gene is expressed in three different size transcripts (i.e. 4, 5 and 11 kb). DRT transcripts are expressed in human brain and several other tissues, including heart, lung, kidney, placenta, pancreas, liver and skeletal muscle, but the 11 kb DRT transcript is preferentially expressed in fetal brain. Steady-state levels of DRT mRNA in several tissues, including brain, heart, lung and kidney, are greater in the midterm fetus than those in the adult. DRT transcripts are detectable at low levels in a human teratocarcinoma cell line (NTera-2), but its expression is greatly increased after the NTera-2 cells are induced to become postmitotic neurons (NTera-2N) by retinoic acid treatment. These data suggest that DRT plays a part in human neurogenesis. A large number of tumor cell lines derived from neuroectoderm express DRT transcripts, including 12 neuroblastomas, two medulloblastomas, one primitive neuroectodermal tumor and six small cell lung carcinomas (SCLC). Interestingly, several neuroblastoma cell lines with 1p deletion and one SCLC cell line express DRT transcripts of aberrant size (i.e. 3, 6 and 8 kb) in addition to those found in normal tissues. We mapped the DRT gene to human chromosome 1p35-1p36.1 by PCR screening of human-rodent somatic cell hybrid panels and by fluorescence in situ hybridization. As the distal end of chromosome 1p is often deleted in neuroblastomas and altered in some cases in SCLCs, these chromosomal abnormalities may have resulted in the generation of aberrant size transcripts. Thus, the DRT gene may play a part in neuroblastoma and SCLC tumorigenesis.
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PMID:Molecular characterization and chromosomal localization of DRT (EPHT3): a developmentally regulated human protein-tyrosine kinase gene of the EPH family. 858 79

HASPP28 (heat- and acid-stable phosphoprotein of 28 kDa) has been purified to near homogeneity from the acid-stable protein fraction of rat brain extract. Based on the N-terminal 40 amino acid sequence, a pair of highly degenerate primers was used to generate a 107-bp probe from rat brain RNA by RT-PCR. From the rat brain lambda gt11 library, this probe identified two positive clones that together provided a cDNA of 837 bp with an open reading frame of 546 bp. This cDNA was extended by 3'RACE to 1.2 kb that included a polyadenylation signal and a poly(A) tail. The 180-amino-acid sequence derived from the open reading frame, which did not correspond to any known protein, was predicted to have phosphorylation sites for protein kinase C, casein kinase II (CKII), and protein kinase A. Indeed, both the purified rat brain HASPP28 and the recombinant HASPP28 (rHASPP28) can be phosphorylated by these kinases. Northern blot analysis indicated that HASPP28 was present in all rat tissues tested, including those from the brain, lung, spleen, kidney, liver, heart, and muscle, in decreasing order of abundance. Phosphopeptide analysis of rHASPP28 phosphorylated in vitro by various kinases showed different tryptic patterns on two-dimensional mapping and isoelectric focusing gels. From [32P]PO4-labeled N1E115 neuroblastoma cells, HASPP28 can be immunoprecipitated with a polyclonal antiserum raised against rHASPP28. The immunoprecipitated protein showed a phosphopeptide pattern similar to that of rHASPP28 phosphorylated by CK II in vitro. Furthermore, the immunoprecipitates from cells treated with phorbol 12-myristate 13-acetate or 8-bromo-cAMP did not show any increased phosphorylation over those of untreated ones, and the phosphopeptide patterns of the immunoprecipitates again were similar to that of CK II phosphorylated protein. These results suggest that HASPP28 is a novel phosphoprotein that can be phosphorylated by several kinases in vitro. In intact cells, CK II seems to be solely responsible for the phosphorylation of HASPP28.
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PMID:Molecular cloning and characterization of a novel casein kinase II substrate, HASPP28, from rat brain. 861 83

Dopamine D4 receptor (DRD4) has received attention in terms of pathogenesis of schizophrenia and association with human personalities. We isolated the human DRD4 gene containing the 5'-flanking region and determined its sequence. Analysis of the DRD4 transcripts by 5'-RACE (5'-rapid amplification of cDNA ends) revealed a region of the transcription initiation located between -501 and -436 relative to the first nucleotide of the initiation codon. There is a CpG island spanning from -900 to +500 but no TATA or CAAT boxes in the 5'-flanking region. Functional analysis of the 5'-flanking region of the DRD4 gene by a transient expression method revealed the presence of a negative modulator between -770 and -679. The region between -591 and -123 gave the highest transcriptional activity in IMR32 (neuroblastoma) and Y-79 (retinoblastoma) cells but not in HeLa cells, suggesting that this housekeeping gene-like promoter regulates the cell-type specific gene expression.
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PMID:Cloning and characterization of the 5'-flanking region of the human dopamine D4 receptor gene. 919 90

The human cytoplasmic serine hydroxymethyltransferase (CSHMT) gene was isolated, sequenced and its expression characterized in human MCF-7 mammary carcinoma and SH_5Y5Y neuroblastoma cells. The 23-kb gene contains 12 introns and 13 exons; all splice junctions conform to the gt/ag rule. The open reading frame is interrupted by 10 introns, two of which are positionally conserved within the human mitochondrial SHMT gene. The gene is expressed with 330 nucleotides of 5' untranslated message within three exons. The 5' promoter region does not contain a consensus TATA, and primer extension and 5'-RACE studies suggest that transcription initiation occurs at multiple sites. Consensus motifs for several regulatory proteins, including SP1, mammary and neuronal-specific elements, NF1, a Y-box, and two steroid hormone response elements, are present within the first 408 nucleotides of the 5' promoter region. The human gene is expressed as multiple splice variants in both the 5' untranslated region and within the open reading frame, all due to exon excision. The splicing pattern is cell-specific. At least six CSHMT mRNA splice forms are present in MCF-7 cells; the gene is expressed as a full-length message as well as splice forms that lack exon(s) 2, 9 and 10. In 5Y cells, the predominant form of the message lacks exon 2, which encodes part of the 5' untranslated region, but does not contain deletions within the open reading frame. Western analysis suggests that the CSHMT gene is expressed as a single full-length protein in 5Y cells, but as multiple forms in MCF-7 cells. Multiple tissue Northern blots suggest that the CSHMT message levels and alternative splicing patterns display tissue-specific variations.
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PMID:Molecular cloning, characterization and alternative splicing of the human cytoplasmic serine hydroxymethyltransferase gene. 957 90

We have previously shown that ZNF74, a candidate gene for DiGeorge syndrome, encodes a developmentally expressed zinc finger gene of the Kruppel-associated box (KRAB) multifinger subfamily. Using RACE, RT-PCR, and primer extension on human fetal brain and heart mRNAs, we here demonstrate the existence of six mRNA variants resulting from alternative promoter usage and splicing. These transcripts encode four protein isoforms differing at their N terminus by the composition of their KRAB motif. One isoform, ZNF74-I, which corresponds to the originally cloned cDNA, was found to be encoded by two additional mRNA variants. This isoform, which contains a KRAB motif lacking the N terminus of the KRAB A box, was devoid of transcriptional activity. In contrast, ZNF74-II, a newly identified form of the protein that is encoded by a single transcript and contains an intact KRAB domain with full A and B boxes, showed strong repressor activity. Deconvolution immunofluorescence microscopy using transfected human neuroblastoma cells and nonimmortalized HS68 fibroblasts revealed a distinct subcellular distribution for ZNF74-I and ZNF74-II. In contrast to ZNF74-I, which largely colocalizes with SC-35 in nuclear speckles enriched in splicing factors, the transcriptionally active ZNF74-II had a more diffuse nuclear distribution that is more characteristic of transcriptional regulators. Taken with the previously described RNA-binding activity of ZNF74-I and direct interaction with a hyperphosphorylated form of the RNA polymerase II participating in pre-mRNA processing, our results suggest that the two ZNF74 isoforms exert different or complementary roles in RNA maturation and in transcriptional regulation.
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PMID:Alternative promoter usage and splicing of ZNF74 multifinger gene produce protein isoforms with a different repressor activity and nuclear partitioning. 1131 19

We previously postulated that the single-minded 2 (SIM2) gene identified on the human chromosome 21q22.2 is a good candidate gene for the pathogenesis of mental retardation in Down syndrome because its mouse homolog exhibits preferential expression in the mouse diencephalon during early embryogenesis. We analyzed the genomic sequence of the entire SIM2 gene which consists of 11 exons and spans over 50 kb. As a step toward understanding the molecular mechanisms of SIM2 gene expression, we have analyzed the human SIM2 gene expression in nine established human cell lines. Three transcripts of 3.6, 4.4, and 6.0 kb were detected in the glioblastoma cell line, T98G, neuroblastoma cell line, TGW, and transformed embryonic kidney cell line, 293. The RACE analysis using SIM2-expressing human cell line T98G provided evidence for the transcription start site at approximately 1.2 kb upstream of the translation initiation site. The transfection assay using various deletion constructs with reporter gene suggested the presence of a presumptive promoter region. Transient transfection assay in T98G cell line revealed a significant promoter activity located in the 60 bp sequence between nt -1385 and -1325 upstream region of the translation initiation site. This 60 bp sequence contains cis-elements for c-myb, E47 and E2F transcription factors. Moreover, the gel retardation assay using oligo-DNA of various cis-element sequences indicated the presence of protein factor(s) which bind to the cis-element for c-myb. These results suggested that binding of a protein transcription factor(s) such as c-myb or that alike regulates transcription of the SIM2 gene by binding to a small upstream region.
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PMID:Molecular mechanisms of human single-minded 2 (SIM2) gene expression: identification of a promoter site in the SIM2 genomic sequence. 1140 25

The M(2) muscarinic receptor inhibits the release of acetylcholine from cholinergic fibers in the lungs and elsewhere. In airway parasympathetic neurons, M(2) receptor expression is decreased by viral infections and by interferon-gamma, increasing actylcholine release. Dexamethasone increases M(2) receptor expression, decreasing acetylcholine release. We carried out 5' rapid amplification of cDNA ends beginning with mRNA from human heart and IMR32 human neuroblastoma cells. This demonstrated a 5' UTR of 100 BP, corresponding to two sequences on chromosome 7, separated by a 22.6 kB intron. The splice acceptor site is at -45 relative to the initiating atg. The 3000 BP upstream of 5' RACE product were subcloned into a pGL3 luciferase reporter vector. Deletional constructs were expressed in IMR32 cells. These demonstrated that 412 BP provided full expression of the reporter gene, and suggested a repressor element between -1848 and -1510.
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PMID:Structure of the human M(2) muscarinic acetylcholine receptor gene and its promoter. 1141 Mar 69

The vesicular GABA transporter (VGAT) loads GABA from neuronal cytoplasm into synaptic vesicles and is selectively expressed in inhibitory neurons that contain GABA and/or glycine. To elucidate the molecular mechanisms of mouse VGAT (mVGAT) gene expression, we have isolated and characterized the mVGAT gene. The mVGAT gene was found to be 4.7 kilobases in size and to contain three exons and two introns by comparison of the cloned genomic DNA with the cDNA (termed mVGATa) sequence reported by Sagne et al. [FEBS Lett. 417 (1997) 177]. Analysis of transcripts and genomic DNA revealed an alternatively spliced mVGAT isoform (termed mVGATb) that retains intron 2 of mVGATa as an exon. This alternative transcript specifies 514 amino acid residues identical to VGATa followed by a unique C-terminal sequence of 11 amino acids encoded by intron 2. Fluorescent in situ hybridization studies showed that the mVGAT gene is localized on chromosome 2. One major transcription start site of the mVGAT gene is an A residue 209 bp upstream from the translational initiation site, as shown using the 5'-RACE method. RT-PCR analysis revealed that the mVGAT gene was expressed at a high level in retinoic acid-treated P19 embryonal carcinoma cells, at a very low level in non-treated P19 cells, and not detectably expressed in Neuro-2a neuroblastoma cells. Sequence analysis of the 5'-flanking region revealed a number of putative regulatory elements including Sp1, Egr-1 and Pitx binding sites. In transient transfection assays, 2 kilobases of the mVGAT 5'-flanking region generated similar levels of luciferase reporter activity in three kinds of cultured cells. Deletion analysis and gel mobility shift assays demonstrated that the region -161 to +155 contained the basal promoter activity of the mVGAT gene and that an activating region from -49 to -27 bound an Sp1-like protein. These results suggest a possible mechanism for regulation of the expression of the mVGAT gene.
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PMID:Mouse vesicular GABA transporter gene: genomic organization, transcriptional regulation and chromosomal localization. 1257 41

Chemoattractant-like receptor 1 (CMKLR1) is a functionally unknown ("orphan") G-protein coupled receptor. It has been implicated in osseous and cartilage development, and it also has a pathophysiological role as one of the minor coreceptors involved in human immunodeficiency virus type I (HIV-1)/simian immunodeficiency virus (SIV) infection of CD4(+) immune cells. Here we report the cloning of the mouse cmklr1 gene, the characterization of its genomic structure for comparison with the human gene, and the mapping and functional analysis of its 5' flanking sequence. The gene was found to contain three exons intercepted by one larger and one smaller intron. The overall structure resembles the human orthologue. The promoter lacks classical TATA and CCAAT boxes but contains several GC-rich regions as well as AP-4 elements, C/EBP motifs, and GATA-1 and GATA-2 binding sites. Promoter function was analyzed in mouse neuroblastoma (NB4 1A3) cells, endogenously expressing CMKLR1, as well as in mouse embryonic fibroblastic (3T3 clone A31) cells not expressing CMKLR1. 5' Deletion analysis and luciferase reporter gene assays of the promoter indicated that a 280-bp sequence adjacent to the transcription start site (established through 5'-RACE) is essential for initiating transcription. Within this region it was possible to identify four potential Sp1-binding sites that may be active in the transcription of the gene. Thus, we show that the mcmklr1 gene has several conserved features in common with its human counterpart, which suggests that they are regulated in a similar manner. The promoter does not seem to be tissue specific but other elements or enhancers may be missing. The results provide a necessary basis for further studies of the gene regulation and function of this chemoattractant-like receptor and will be useful when manipulating the gene in the development of transgenic animal models.
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PMID:Genomic organization and promoter analysis of the gene encoding the mouse chemoattractant-like receptor, CMKLR1. 1501 96

Glial cell line-derived neurotrophic factor (GDNF) is a survival factor for many neuronal cell types and has wide ranging effects within the central nervous system. To investigate the expression of the GDNF gene in immune cell lines under inflammatory conditions, we pharmacologically estimated the induction of GDNF mRNA in RAW264.7 cells. RT-PCR analysis revealed that LPS-induced GDNF mRNA in RAW264.7 cells does not include exon 3, which encodes the translational start site of this gene. A novel type of GDNF mRNA cloned by 5'-RACE consisted of the previous exon 4 and its flanking 5' upstream region, akin to a single exon gene. A similar type of human GDNF mRNA was also detected in a human neuroblastoma cell line, SH-SY5Y, without any stimulation. This novel (Ex4) GDNF mRNA was also upregulated by LPS in primary cultured rat macrophages, microglia and astrocytes and was found to exist in mouse brain. Ex4 GDNF protein produced by transfected HEK293 cells was mainly detected in cell lysates, but in conditioned medium only after PMA stimulation. Ex4 GDNF protein was found to exist as an unglycosylated form in both the transfected cells and the conditioned medium while full-type GDNF protein is glycosylated. PMA-stimulated augmentation of unglycosylated Ex4 GDNF protein was demonstrably regulated at the post-translational level.
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PMID:Identification of a novel GDNF mRNA induced by LPS in immune cell lines. 1829 22


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