Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0004135 (ATM)
 13,001 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Ataxia-telangiectasia (A-T) is an inherited human disease of unknown etiology associated with neurologic degeneration, immune dysfunction, cancer risk, and genetic instability. A-T cells are sensitive to ionizing radiation and radiomimetic drugs, offering the possibility of cloning A-T genes by phenotypic complementation. We have used this sensitivity to isolate the first human cDNAs reported to complement A-T cells in culture. Complementation group D A-T fibroblasts were transfected with an episomal vector-based human cDNA library, approximately 610,000 resultant transformants were treated with the radiomimetic drug streptonigrin-resistant, and nine unrelated cDNAs were recovered from 29 surviving streptonigrin-resistant clones. Five cDNAs were mapped, but none localized to 11q23, the site of A-T complementation group A and C loci. Four of the mapped cDNAs conferred mutagen resistance to A-T D fibroblasts on secondary transfection. One cDNA was identified as a fragment of dek, a gene involved in acute myeloid leukemia. The dek cDNA fragment and pCAT4.5, a 4.5-kb cDNA that mapped to 17p11, independently complemented three different phenotypic abnormalities of A-T D fibroblasts (mutagen sensitivity, hyper-recombination, and radio-resistant DNA synthesis). The pCAT4.5 cDNA did not complement the mutagen sensitivity of an A-T group C fibroblast line, suggesting that it represents a candidate disease gene for group D A-T. Our results indicate that phenotypic complementation alone is insufficient evidence to prove that a candidate cDNA is an A-T disease gene. The complementing cDNAs may represent previously uncharacterized genes that function in the same pathway as does the A-T gene product(s) in the regulation of cellular responses to DNA damage.
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PMID:Expression cloning of multiple human cDNAs that complement the phenotypic defects of ataxia-telangiectasia group D fibroblasts. 750 6

The product of the dek oncogene is the 43-kDa DEK nuclear protein. DEK was first identified in a fusion with the CAN nucleoporin protein in a specific subtype of acute myelogenous leukemia. DEK has also been shown to be an autoantigen in patients with pauciarticular onset juvenile rheumatoid arthritis. Further, the last 65 amino acids of DEK can partially reverse the mutation-prone phenotype of cells from patients with ataxia-telangiectasia. However, in spite of these significant disease associations, the function of DEK has remained unclear. The HIV-2 peri-ets (pets) site is a TG-rich element found between the two Elf-1 binding sites in the HIV-2 enhancer. The pets element mediates transcriptional activation whether the enhancer is stimulated by phorbol 12-myristate 13-acetate (PMA) alone, phytohemagluttinin (PHA) alone, PMA plus PHA, soluble antibodies to the T cell receptor, immobilized antibodies to the T cell receptor, or by antigen. Previously, we purified and characterized the pets factor, demonstrating that it is a 43-kDa nuclear protein. We now describe the identification of DEK as this 43-kDa pets factor. Using a modified Southwestern screening procedure, we find that DEK can recognize the pets element. We demonstrate the ability of recombinant DEK to bind specifically to the pets site using the electrophoretic mobility shift assay (EMSA) and DNase I footprinting. "Supershift" EMSA further confirms that DEK is the dominant protein binding to the pets site in T cell extracts. Our findings show that DEK is a site-specific DNA binding protein that is likely involved in transcriptional regulation and signal transduction. This has implications for multiple pathogenic processes, including hematologic malignancies, arthritis, ataxia-telangiectasia, and AIDS caused by HIV-2.
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PMID:DEK, an autoantigen involved in a chromosomal translocation in acute myelogenous leukemia, binds to the HIV-2 enhancer. 905 Aug 61

The mammalian protein DEK has been implicated in multiple cellular processes, including transcriptional regulation, mRNA processing, and chromatin remodeling, and is associated with a number of clinical autoimmune and neoplastic conditions. The connection between DEK and cancer exists at multiple levels: (a) the t(6;9) chromosomal translocation that characterizes a subtype of acute myelogenous leukemia cases results in the formation of a DEK-CAN fusion oncoprotein; (b) a fragment of dek cDNA is capable of partially reversing the radiation-sensitive phenotype of fibroblasts cultured from ataxia-telangiectasia patients; and (c) increased levels of dek mRNA have been found to be associated with hepatocellular carcinoma, glioblastoma, and melanoma. Despite the growing list of cancer subtypes with a connection to DEK, the factors that mediate its expression have yet to be characterized. Here we undertake the analysis of DEK regulation by mapping the discrete elements within the proximal promoter that are responsible for constitutive transcription of dek in transformed cells. We find that functional elements include an inverted CCAAT box and a YY1 consensus binding site, and the introduction of point mutations into these sites markedly diminishes transcriptional activity. In addition, we identify the transcriptional activator NF-Y as a member of the CCAAT-binding complex, and verify binding of the transcription factor YY1 at its consensus site in the dek promoter. The discovery of NF-Y and YY1 as regulatory determinants of DEK expression is consistent with the well-documented roles of these two factors in cellular proliferation and transformation.
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PMID:YY1 and NF-Y binding sites regulate the transcriptional activity of the dek and dek-can promoter. 1248 38

The chromatin-associated protein DEK was first identified as a fusion protein in patients with a subtype of acute myelogenous leukemia. It has since become associated with diverse human ailments ranging from cancers to autoimmune diseases. Despite much research effort, the biochemical basis for these clinical connections has yet to be explained. We have identified a structural domain in the C-terminal region of DEK [DEK(309-375)]. DEK(309-375) implies clinical importance because it can reverse the characteristic abnormal DNA-mutagen sensitivity in fibroblasts from ataxia-telangiectasia (A-T) patients. We determined the solution structure of DEK(309-375) by nuclear magnetic resonance spectroscopy, and found it to be structurally homologous to the E2F/DP transcription factor family. On the basis of this homology, we tested whether DEK(309-375) could bind DNA and identified the DNA-interacting surface. DEK presents a hydrophobic surface on the side opposite the DNA-interacting surface. The structure of the C-terminal region of DEK provides insights into the protein function of DEK.
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PMID:Solution NMR structure of the C-terminal domain of the human protein DEK. 1523 33

The 375 amino acid human protein DEK has been expressed in two functional, structured domains. DEK is an abundant nuclear protein that associates with chromatin and alters its topology by introducing positive supercoiling in DNA, which results in lower replication efficiency. DEK has clinical importance as transfection of the cDNA of the C-terminal region of DEK can partially reverse the abnormal DNA-mutagen sensitivity in fibroblasts derived from ataxia-telangiectasia (A-T) patients, and elevated levels of DEK mRNA are observed in various forms of cancer. Because high-level expression of full-length DEK has proved elusive, we sought an alternative for structural studies that would provide insights on DEK's function. We have discovered that DEK contains two structured domains and have expressed these domains at a high level in Escherichia coli in M9 minimal media. The N-terminal domain (amino acids 68-226) includes the region responsible for introducing supercoils into DNA, and the C-terminal domain (amino acids 309-375) includes the region that can reverse the abnormal DNA-mutagen sensitivity of A-T cells. 1H-15N correlation nuclear magnetic resonance spectra of these two fragments reveal the characteristic signature of folded proteins.
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PMID:Expression and isotopic labeling of structural domains of the human protein DEK. 1576 65