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101.
Banks M. Graber P. Proudfoot A. E. I. Arod C. Y. Allet B. Bernard A. R. Sebille E. Mckinnon M. Wells T. N. C. Solari R. 《Analytical biochemistry》1995,230(2)
Interleukin-5 (IL-5) is a key cytokine for the production, differentiation, and activation of eosinophils. IL-5 is a member of the four helical bundle family of cytokines, and in common with many members of the cytokine family it binds to a heterodimeric receptor composed of a ligand binding α-chain and a signal-transducing β-chain. We have established two receptor/ligand binding assays based on the extracellular domain of the receptor α-chain which we have produced as a fusion protein. One assay is based on scintillation proximity fluoromicrospheres and radiolabeled ligand and the other on detection of biotinylated ligand binding to immobilized receptor using a chemiluminescent substrate in a 96-well microtiter plate format. Both receptor binding assays have been optimized for high throughput screening for receptor antagonists. These assays were also used for analytical purposes and the binding of ligand to the receptor α-chain was compared directly to receptor binding assays performed on TF-1 cells which express the receptor αβ-heterodimer. These three assays have been used to study site-directed mutants of IL-5 to determine the important residues for interaction of the cytokine with each chain of the receptor (P. Graber et al. (1995) J. Biol. Chem. 270, 15762-15769). 相似文献
102.
Clinical phenotype of nephrogenic diabetes insipidus in females heterozygous for a vasopressin type 2 receptor mutation 总被引:2,自引:0,他引:2
Angenita F. van Lieburg Marian A. J. Verdijk Frans Schoute Marjolijn J. L. Ligtenberg Bernard A. van Oost Franz Waldhauser Maria Dobner Leo A. H. Monnens Nine V. A. M. Knoers 《Human genetics》1995,96(1):70-78
Nephrogenic diabetes insipidus (NDI) usually shows an X-linked recessive mode of inheritance caused by mutations in the vasopressin type 2 receptor gene (AVPR2). In the present study, three NDI families are described in which females show clinical features resembling the phenotype in males. Maximal urine osmolality in three female patients did not exceed 200 mosmol/kg and the absence of extra-renal responses to 1-desamino-8-d-arginine vasopressin was demonstrated in two of them. All affected females and two asymptomatic female family members were shown to be heterozygous for an AVPR2 mutation. Skewed X-inactivation is the most likely explanation for the clinical manifestation of NDI in female carriers of an AVPR2 mutation. It is concluded that, in female NDI patients, the possibility of heterozygosity for an AVPR2 gene mutation has to be considered in addition to homozygosity for mutations in the aquaporin 2 gene. 相似文献
103.
Emmanuel Martin Valère Cacheux Hélène Cavé Jean Michel Lapierre Denis Le Paslier Bernard Grandchamp 《Human genetics》1995,96(6):668-670
CDKN4/p27Kip1 is a cyclin-dependent kinase (Cdk) inhibitor implicated in G1 phase arrest, which negatively regulates G1 phase progression in response to TGF, and might represent a tumor suppressor gene. We report here the chromosomal assignment of the human CDKN4 gene to chromosome 12p12.3 in close proximity to highly polymorphic microsatellite markers. 相似文献
104.
Sophie Rousseaux Edith Chevret Michèle Monteil Jean Cozzi Roberte Pelletier Didier Delafontaine Bernard Sèle 《Human genetics》1995,96(6):655-660
The meiotic segregation of chromosomes 14 and 21 was analysed in 1116 spermatozoa from an oligoasthenospermic carrier of a Robsertsonian translocation t(14q21q), and in 16 392 spermatozoa from a control donor, using two-colour fluorescence in situ hybridisation (FISH). Two YAC probes (cloned in yeast artificial chromosomes) specific for regions on the long arms of these chromosomes were co-hybridised. Of the spermatozoa, 12% were unbalanced, resulting from adjacent segregations. Chromosomes X, Y and 1 were also simultaneously detected in 1335 spermatozoa from the same carrier. Whereas gonosomal disomy rates were not significantly different from those of the control donors, disomy 1 were slightly but significantly increased to 0.7%. The diploidy rate was also slightly increased to approximately 1% in the translocation carrier. 相似文献
105.
Gabriel Guillet Marie-Ève Lavigne Bernard J. R. Philogène J. Thor Arnason 《Journal of Insect Behavior》1995,8(4):533-546
Two phototoxic plants of the Asteraceae family were studied in relation to species of phytophagous insects for which they are hosts:Argyrotaenia velutinana Wlk. feeding onChrysanthemum leucanthemum L. andChlorochlamys chloroleucaria (Guenée) colonizingRudbeckia hirta L. The toxicity of these two plants is related to the presence of acetylenes and thiophenes that induce a light-mediated production of deleterious singlet oxygen and other free radicals (phototoxicity). Results showed that females ofA. velutinana laid their eggs preferentially in the shade and the larvae adopted hiding behaviors, such as bending of ligulate corollas and silk spinning to build opaque shelters. By avoiding direct exposure to the sun, both behaviors may reduce phototoxicity associated with ingested plant materials. Furthermore, larvae ofC. chloroleucaria demonstrated a preference in the field for pollen, which constitutes a nonphototoxic tissue of their host plant. Experimental alterations of these specific behaviors induced important biological consequences for larvae of both insects such as mortality or reduction of larval growth rate. These results reinforce the idea that behavior may constitute an efficient adaptation to avoid phototoxicity. 相似文献
106.
107.
Is hydrogen peroxide a second messenger of salicylic acid in systemic acquired resistance? 总被引:18,自引:1,他引:17
Urs Neuenschwander Bernard Vernooij Leslie Friedrich Scott Uknes Helmut Kessmann John Ryals 《The Plant journal : for cell and molecular biology》1995,8(2):227-233
Elevated levels of salicylic acid (SA) are required for the induction of systemic acquired resistance (SAR) in plants. Recently, a salicylic acid-binding protein (SABP) isolated from tobacco was shown to have catalase activity. Based on this finding elevated levels of hydrogen peroxide (H2 O2 ) were postulated to act as a second messenger of SA in the SAR signal transduction pathway. A series of experiments have been carried out to clarify the role of H2 O2 in SAR-signaling. No increase of H2 O2 was found during the onset of SAR. Induction of the SAR gene, PR-1, by H2 O2 and H2 O2 -inducing chemicals is strongly suppressed in transgenic tobacco plants that express the bacterial salicylate hydroxylase gene, indicating that H2 O2 induction of SAR genes is dependent on SA accumulation. Following treatment of plants with increasing concentrations of H2 O2 , a dose-dependent accumulation of total SA species was found, suggesting that H2 O2 may induce PR-1 gene expression through SA accumulation. While the results do not support a role for H2 O2 in SAR signaling, it is suggested that SA inhibition of catalase activity may be important in tissues undergoing a hypersensitive response. 相似文献
108.
The mechanism of the aniline hydroxylase activity of methaemoglobin in a monooxygenase system consisting of NADH as electron donor, riboflavin, FAD, FMN or methylene blue as electron carrier and methaemoglobin as the terminal oxidase has been studied. Hydrogen peroxide is produced from oxygen in a methaemoglobin-independent process. 4-Aminophenol is subsequently produced peroxidatively by an NADH-dependent process; NADH prevents a further oxidation of 4-aminophenol in the presence of haemoglobin. In the absence of electron carrier, NADH slowly reduces haemoglobin and then oxyhaemoglobin reacts with aniline to give 4-aminophenol. In the absence of electron donor and electron carrier, oxyhaemoglobin and aniline give rise to the reversible production of 4-aminophenol. 相似文献
109.
Cytosolic and nuclear forms of the glucocorticoid receptor were characterized using immunochemical techniques. Antibodies were raised in rabbits to an Mr 58,000 fragment of the transformed (DNA-binding) glucocorticoid receptor purified from rat liver cytosol by DNA-cellulose chromatography and polyacrylamide gel electrophoresis. Antibodies reacted with the transformed receptor form in a radioimmunoassay for glucocorticoid receptor. Western blot analysis of antibody reactivity revealed a single Mr 185,000 receptor form in rat liver cytosol but a smaller Mr 85,000 form in nucleosol, indicating the Mr 85,000 form is the transformed receptor. Furthermore, western blot analysis indicates that the Mr 185,000 receptor undergoes proteolysis during receptor purification and in vitro transformation processes by generating immunochemically similar proteins of smaller molecular weights. An identical Mr 185,000 glucocorticoid receptor was detected in cytosols of four rat tissues; liver, brain, adrenal medulla, and thymus. The glucocorticoid receptor was localized to the cytoplasm and nucleus of rat adrenal medulla cells by immunohistochemistry, demonstrating the existence in vivo of the transformed receptor and translocation of the receptor from cytoplasm to nucleus. 相似文献
110.
Bernard Knight 《BMJ (Clinical research ed.)》1978,1(6116):840-841