Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

G-box (CCACGTGG) like sequences are present in a variety of plant promoters and in many cases they have been demonstrated to be required for maximal expression of the corresponding gene. A nuclear protein, GBF, interacts specifically with the G-box motif of several RBCS and CAB promoters. Here we describe the isolation of a cDNA from Arabidopsis thaliana that encodes a protein, designated GBF-1, with DNA binding properties similar to GBF. GBF-1 is characterized by a basic/leucine zipper motif which is strikingly similar to the wheat protein identified as HBP-1. GBF-1 also interacts with an oligonucleotide derived from the wheat histone 3 promoter containing the binding site (hexamer, TGACGT) for HBP-1. This DNA element also contains a G-box-like motif, modification of which results in loss in binding of GBF-1.
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PMID:An Arabidopsis thaliana G-box-binding protein similar to the wheat leucine zipper protein identified as HBP-1. 184 10

Wheat transcription factors HBP-1a and HBP-1b bind to the hexamer motif, ACGTCA, of wheat histone gene promoters. HBP-1b also binds to the hexamer motif in the promoter of the 35S RNA gene of cauliflower mosaic virus, whereas HBP-1a does not. A cDNA clone encoding HBP-1b was isolated on the basis of its binding specificity to the hexamer motif. The deduced amino acid sequence indicates that HBP-1b, like HBP-1a, belongs to a leucine zipper class of transcription factors. Mutational analyses of the HBP-1a and -1b encoded cDNAs revealed that truncated polypeptides containing the leucine zipper and basic regions are sufficient for DNA binding. HBP-1a and -1b form homodimers, as expected from earlier studies on this class of transcription factors, but did not form heterodimers. Although the hexamer motif or its homologs exist in several plant genes, HBP-1a and -1b exhibited the highest binding affinity to the hexamer motif in the histone promoters, suggesting that both DNA binding proteins are involved in transcriptional regulation of wheat histone genes.
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PMID:HBP-1a and HBP-1b: leucine zipper-type transcription factors of wheat. 202 43

We identified two novel DNA-binding proteins, ssDBP-1 and ssDBP-2, in wheat germ nuclear extract that interact with the proximal sequences of the promoter regions of the wheat histone H3 and H4 genes. Mobility shift and methylation interference assays have demonstrated that these factors specifically bind to the single-strand DNA which partially overlaps the hexamer and octamer cis-elements of the H3 promoter. Both proteins are distinguishable from HBP-1a and HBP-1b which specifically bind to the H3 hexamer sequence. These ssDNA-binding proteins are supposed to regulate the transcription of the wheat histone genes.
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PMID:Sequence-specific single-strand DNA-binding proteins that interact with the regulatory regions of wheat histone H3 and H4 genes. 203 33

Proteinases and their inhibitors have become the subject of intense research interest recently, since they control a multitude of very important biological processes, from the development of lambda phage to hypertension in humans. We have developed a simple and sensitive assay for detecting the activity of proteinases and of their proteinase inhibitors. The assay is based on ethidium bromide fluorescence, according to the following principles: (i) Ethidium bromide increases its fluorescence by 25-fold when it intercalates between base pairs of double-stranded DNA. (ii) Histones prevent this large increase in fluorescence by binding with high affinity to DNA thus blocking ethidium bromide intercalation. (iii) A proteinase that digests histones will make more DNA available for ethidium bromide intercalation, thereby producing an increase of fluorescence. Proteinase activity can easily be determined, in the presence of a DNA/histone complex, from the rate of ethidium fluorescence increase. In contrast, activity of a proteinase inhibitor is quantitated by the inhibition of fluorescence gain in the presence of a known amount of proteinase. This assay is rapid, simple, inexpensive, and, at the same time, accurate and sensitive enough to allow quantitation of nanogram amounts of various broad-specificity proteinases and their inhibitors. We show some possible applications of the assay (i) in testing column fractions during protein purifications, (ii) quantitation of alpha 1-antitrypsin in human serum, and (iii) detection of proteinase activity in cell extracts.
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PMID:An assay for proteinases and their inhibitors based on DNA/ethidium bromide fluorescence. 204 45

A majority of histone genes are expressed in the S phase during the cell cycle. Using the gene expression system of transformed sunflower cells into which wheat histone H3 gene was introduced by the Ti-plasmid gene transfer technique, we determined three cis-acting control sequences (hexameric, octameric, and nonameric motifs) which seemed to confer the S-phase-specific transcription of wheat histone genes. Furthermore, as candidates for regulatory transcription factors, three nuclear DNA-binding proteins HBP-1a, HBP-1b, and HBP-2 that interact with the hexameric and nonameric motifs were identified. The structural analysis of the cDNA of HBP-1a revealed that a nuclear protein has the leucine-zipper structure and a DNA-binding motif. The hexameric motif in the H3 gene was also seen in cauliflower mosaic virus 35S (CaMV 35S) promoter and shown to function as a regulatory element of this promoter. The wheat HBP-1b can interact with the hexameric motif of the CaMV 35S promoter. Much attention has been paid to the significance of the hexameric sequences within the H3 and CaMV 35S promoters and the DNA-binding proteins HBP-1a and HBP-1b.
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PMID:Cell cycle-regulated gene expression in transgenic plant cells. 227 56

The hexameric sequence ACGTCA functions in transcriptional regulation of wheat histone genes. The cauliflower mosaic virus (CaMV) 35S RNA promoter has the same hexameric sequence, and mutation analyses confirmed that the hexamer contributed greatly to transcription from the 35S promoter when a test gene with this promoter was introduced into sunflower cells. Electrophoretic mobility shift assays revealed the existence of a nuclear protein(s) in sunflower cells which is homologous to the HBP-1b that has been identified as binding to the 35S promoter in wheat. These results provide evidence of the involvement of the hexameric sequence and the HBP-1b-like DNA binding protein(s) in transcription from the 35S promoter.
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PMID:Function of the hexameric sequence in the cauliflower mosaic virus 35S RNA promoter region. 247 31

The structure and function of transcription factors of higher plants was studied by isolating cDNA clones encoding a wheat sequence-specific DNA binding protein. A hexameric nucleotide motif, ACGTCA, is located upstream from the TATA box of several plant histone genes. It has been suggested that this motif is essential for efficient transcription of the wheat histone H3 gene. A wheat nuclear protein, HBP-1 (histone DNA binding protein-1), which specifically binds to the hexameric motif, has previously been identified as a putative transcription factor. A cDNA clone encoding HBP-1 has been isolated on the basis of specific binding of HBP-1 to the hexameric motif. The deduced amino acid sequence indicates that HBP-1 contains the leucine zipper motif, which represents a characteristic property of several eukaryotic transcription factors.
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PMID:A protein that binds to a cis-acting element of wheat histone genes has a leucine zipper motif. 277 48

A nuclear protein(s), HBP-2, that binds to the upstream region of the wheat histone H4 gene was identified from a fractionated nuclear extract of wheat germ by DNase I footprinting. The DNase I-protected region contained the conserved nonameric motif, CATCCAACG. Cross-competition experiments that used the mobility shift assay showed that this nuclear protein(s) binds specifically to the upstream sequence that has been postulated to be a cis element of the wheat H3 gene. Our findings suggest that this DNA-binding protein(s) may be a trans-acting factor in the regulation of the transcription of wheat histone genes.
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PMID:DNA-binding protein(s) interacts with a conserved nonameric sequence in the upstream regions of wheat histone genes. 318 34

Wheat basic/leucine zipper protein HBP-1a(17) binds in vitro specifically to ACGT motif-containing cis-acting elements, such as the type I element of plant histone promoters and the G-box of hormone- and light-inducible promoters. To address the in vivo function of HBP-1a(17), we isolated and structurally analyzed the HBP-1a(17) gene and examined its expression in transgenic Arabidopsis plants. The HBP-1a(17) gene is composed of 14 exons; the basic region and leucine zipper are encoded by separate small exons, as is the case for other bZIP protein genes. The G-box of the HBP-1a(17) promoter bound specifically to HBP-1a(17) and its related HBP-1a isoforms, suggesting that the HBP-1a(17) gene may be autoregulated, although the binding affinity of these proteins in vitro is very low. In Arabidopsis plants, activation of the HBP-1a(17) promoter was highly restricted to photosynthetically active mesophyll, and guard cells and vascular bundles of vegetative leaves. Etiolation of transgenic plants resulted in inhibition of expression of the HBP-1a(17) promoter. Indeed, the HBP-1a(17) promoter contains several sequence elements homologous to cis-acting elements conserved in light-inducible promoters. It is, therefore, assumed that the HBP-1a(17) gene is light regulated and that HBP-1a(17) is involved in light-responsive gene transcription via the G-box.
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PMID:Developmental and tissue-specific regulation of the gene for the wheat basic/leucine zipper protein HBP-1a(17) in transgenic Arabidopsis plants. 747 57

A 58 year old woman developed systemic symptoms, interstitial lung disease, splenomegaly, leukopenia and anti-histone and anti-nuclear antibodies (ANA), while treated with hydralazine for hypertension. Five months after presentation she was admitted with high fever, skin rash and atypical lymphocytosis due to acute cytomegalovirus (CMV) infection. Worsening leukopenia and increased ANA were found, and high titres of anti-DNA antibodies, anti-cardiolipin antibodies and rheumatoid factors appeared. Hydralazine was stopped and the patient gradually became asymptomatic. All autoantibodies spontaneously disappeared (over 16 weeks), and the white cell count and spleen size became normal. The patient was found to be a slow acetylator and to have both HLA-DR4 and selective IgA deficiency. Thus, a multifactorial genetic susceptibility to develop drug-induced lupus was brought out in stages first by hydralazine and then by CMV, yet all manifestations and autoantibodies resolved spontaneously, demonstrating the complex interplay of varied environmental factors with a genetic predisposition in the pathogenesis of autoimmunity.
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PMID:Effect of acute cytomegalovirus infection on drug-induced SLE. 783 Nov 73


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