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Summary The total amount of bound adenine nucleotides in the coupling factor isolated from spinach chloroplasts and its distribution on AMP, ADP and ATP was analyzed after various incubation conditions. During purification of the coupling factor, the distribution of AMP, ADP and ATP is not altered. The coupling factor from deenergized membranes contains approximately 1 ADP, less than 1 ATP, and small amounts of AMP. During phosphorylation the pattern is changed and ATP becomes the dominant species. When exogenous ADP is lacking, phosphate is readily incorporated into ATP. Inhibition of adenylate kinase by AP5A does not change the distribution pattern of the adenine nucleotides. The distribution pattern shows no integer numbers for the different nucleotides, suggesting that the coupling factor is present in different states in a statistical distribution.Acknowledgment: We thank the Swiss National Foundation for Scientific Research (grant 3.582.79) for generous support. 相似文献
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H. U. Wanner 《Cellular and molecular life sciences : CMLS》1993,49(9):754-758
Most air pollutants do not lead to specific diseases. Depending on the pollutant, the concentration and the duration of exposure, some organs are more affected than others. The most frequent disorders are those caused by irritant gases and particulates on the mucous membranes and respiratory organs. The consequences are eye, nose and throat inflammations, diminished lung function, increased susceptability to respiratory infection and a higher incidence of chronic bronchitis. These disorders and diseases are, of course, influenced by other factors as well, such as immune deficiency, allergies, occupational exposure to pollutants, and particularly smoking. The effects of air pollutants are, therefore, multifactorially conditioned and nonspecific disorders are placed in the foreground. Evidence for an association of air pollution with adverse effects on human health is drawn from three sources: animal experiments, experimental human exposures, and epidemiologic studies of exposed human populations. The burden of atmospheric pollution must be reduced to protect human health by an adequate safety margin. In particular, the increased sensitivity of sick and aged people as well as children should be taken into account. In defining the maximum emmission levels, preventive aspects should have priority so as to keep the risk of damage to health and the harmful influences on the environment to a minimum.This article Effects of atmospheric pollution on human health by H. U. Wanner is a revised version of the same article that was first published in the Proceedings of the 1990 European Aerosol Conference; special issue of the J. Aerosol Sci., Vol. 21, Suppl. 1 (1990) 389–396.Reprinted with kind permission from Pergamon Press Ltd, Headington Hill Hall, Oxford OX3 0BW, Great Britain. 相似文献
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Hoffmann K Dreger CK Olins AL Olins DE Shultz LD Lucke B Karl H Kaps R Müller D Vayá A Aznar J Ware RE Sotelo Cruz N Lindner TH Herrmann H Reis A Sperling K 《Nature genetics》2002,31(4):410-414
Pelger-Hu?t anomaly (PHA; OMIM *169400) is an autosomal dominant disorder characterized by abnormal nuclear shape and chromatin organization in blood granulocytes. Affected individuals show hypolobulated neutrophil nuclei with coarse chromatin. Presumed homozygous individuals have ovoid neutrophil nuclei, as well as varying degrees of developmental delay, epilepsy and skeletal abnormalities. Homozygous offspring in an extinct rabbit lineage showed severe chondrodystrophy, developmental anomalies and increased pre- and postnatal mortality. Here we show, by carrying out a genome-wide linkage scan, that PHA is linked to chromosome 1q41-43. We identified four splice-site, two frameshift and two nonsense mutations in LBR, encoding the lamin B receptor. The lamin B receptor (LBR), a member of the sterol reductase family, is evolutionarily conserved and integral to the inner nuclear membrane; it targets heterochromatin and lamins to the nuclear membrane. Lymphoblastoid cells from heterozygous individuals affected with PHA show reduced expression of the lamin B receptor, and cells homozygous with respect to PHA contain only trace amounts of it. We found that expression of the lamin B receptor affects neutrophil nuclear shape and chromatin distribution in a dose-dependent manner. Our findings have implications for understanding nuclear envelope-heterochromatin interactions, the pathogenesis of Pelger-like conditions in leukemia, infection and toxic drug reactions, and the evolution of neutrophil nuclear shape. 相似文献
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The genome sequence of the filamentous fungus Neurospora crassa 总被引:1,自引:0,他引:1
Galagan JE Calvo SE Borkovich KA Selker EU Read ND Jaffe D FitzHugh W Ma LJ Smirnov S Purcell S Rehman B Elkins T Engels R Wang S Nielsen CB Butler J Endrizzi M Qui D Ianakiev P Bell-Pedersen D Nelson MA Werner-Washburne M Selitrennikoff CP Kinsey JA Braun EL Zelter A Schulte U Kothe GO Jedd G Mewes W Staben C Marcotte E Greenberg D Roy A Foley K Naylor J Stange-Thomann N Barrett R Gnerre S Kamal M Kamvysselis M Mauceli E Bielke C Rudd S Frishman D Krystofova S Rasmussen C Metzenberg RL 《Nature》2003,422(6934):859-868
Neurospora crassa is a central organism in the history of twentieth-century genetics, biochemistry and molecular biology. Here, we report a high-quality draft sequence of the N. crassa genome. The approximately 40-megabase genome encodes about 10,000 protein-coding genes--more than twice as many as in the fission yeast Schizosaccharomyces pombe and only about 25% fewer than in the fruitfly Drosophila melanogaster. Analysis of the gene set yields insights into unexpected aspects of Neurospora biology including the identification of genes potentially associated with red light photobiology, genes implicated in secondary metabolism, and important differences in Ca2+ signalling as compared with plants and animals. Neurospora possesses the widest array of genome defence mechanisms known for any eukaryotic organism, including a process unique to fungi called repeat-induced point mutation (RIP). Genome analysis suggests that RIP has had a profound impact on genome evolution, greatly slowing the creation of new genes through genomic duplication and resulting in a genome with an unusually low proportion of closely related genes. 相似文献
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Intracardiac fluid forces are an essential epigenetic factor for embryonic cardiogenesis 总被引:24,自引:0,他引:24
The pattern of blood flow in the developing heart has long been proposed to play a significant role in cardiac morphogenesis. In response to flow-induced forces, cultured cardiac endothelial cells rearrange their cytoskeletal structure and change their gene expression profiles. To link such in vitro data to the intact heart, we performed quantitative in vivo analyses of intracardiac flow forces in zebrafish embryos. Using in vivo imaging, here we show the presence of high-shear, vortical flow at two key stages in the developing heart, and predict flow-induced forces much greater than might have been expected for micro-scale structures at low Reynolds numbers. To test the relevance of these shear forces in vivo, flow was occluded at either the cardiac inflow or outflow tracts, resulting in hearts with an abnormal third chamber, diminished looping and impaired valve formation. The similarity of these defects to those observed in some congenital heart diseases argues for the importance of intracardiac haemodynamics as a key epigenetic factor in embryonic cardiogenesis. 相似文献
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Nicole Schwarz Jessica Pruessmeyer Franz M. Hess Daniela Dreymueller Elena Pantaler Anne Koelsch Reinhard Windoffer Matthias Voss Alisina Sarabi Christian Weber Antonio S. Sechi Stefan Uhlig Andreas Ludwig 《Cellular and molecular life sciences : CMLS》2010,67(24):4233-4248
The surface-expressed transmembrane CX3C chemokine ligand 1 (CX3CL1/fractalkine) induces firm adhesion of leukocytes expressing its receptor CX3CR1. After shedding by the disintegrins and metalloproteinases (ADAM) 10 and 17, CX3CL1 also acts as soluble leukocyte chemoattractant. Here, we demonstrate that transmembrane CX3CL1 expressed on both endothelial and epithelial cells induces leukocyte transmigration. To investigate the underlying mechanism, we generated CX3CR1 variants lacking the intracellular aspartate-arginine-tyrosine (DRY) motif or the intracellular C-terminus which led to a defect in intracellular calcium response and impaired ligand uptake, respectively. While both variants effectively mediated firm cell adhesion, they failed to induce transmigration and rather mediated retention of leukocytes on the CX3CL1-expressing cell layer. Targeting of ADAM10 led to increased adhesion but reduced transmigration in response to transmembrane CX3CL1, while transmigration towards soluble CX3CL1 was not affected. Thus, transmembrane CX3CL1 mediates leukocyte transmigration via the DRY motif and C-terminus of CX3CR1 and the activity of ADAM10. 相似文献
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Linda Reinhard Henning Tidow Michael J. Clausen Poul Nissen 《Cellular and molecular life sciences : CMLS》2013,70(2):205-222
The Na+,K+-ATPase, or sodium pump, is well known for its role in ion transport across the plasma membrane of animal cells. It carries out the transport of Na+ ions out of the cell and of K+ ions into the cell and thus maintains electrolyte and fluid balance. In addition to the fundamental ion-pumping function of the Na+,K+-ATPase, recent work has suggested additional roles for Na+,K+-ATPase in signal transduction and biomembrane structure. Several signaling pathways have been found to involve Na+,K+-ATPase, which serves as a docking station for a fast-growing number of protein interaction partners. In this review, we focus on Na+,K+-ATPase as a signal transducer, but also briefly discuss other Na+,K+-ATPase protein–protein interactions, providing a comprehensive overview of the diverse signaling functions ascribed to this well-known enzyme. 相似文献