A single STAT recruitment module in a chimeric cytokine receptor complex is sufficient for STAT activation

in Journal of Biological Chemistry (1997), 272(8), 5269-74

We established a system of receptor chimeras that enabled us to induce heterodimerization of different cytoplasmic tails. Fusion constructs were created that are composed of the extracellular parts of the ... [more ▼]

We established a system of receptor chimeras that enabled us to induce heterodimerization of different cytoplasmic tails. Fusion constructs were created that are composed of the extracellular parts of the interleukin-5 receptor alpha and beta chains, respectively, and the transmembrane and intracellular parts of gp130, the signal transducing chain of the interleukin-6 receptor complex. In COS-7 transfectants we observed a dose-dependent interleukin-5-inducible STAT1 activation for which the presence of both the alpha and the beta chain chimera was needed. No STAT activity was detected if one of the cytoplasmic tails of the receptor complex was deleted, indicating that STAT activity resulted from a receptor dimer rather than from higher receptor aggregates. We further investigated whether dimerization of STAT1 depends on the juxtaposition of two STAT recruitment modules in a receptor complex. We show that a receptor dimer with only a single STAT1 docking site was still able to lead to STAT1 activation. This indicates that the formation of a paired set of STAT binding sites in a receptor complex is not the prerequisite for STAT factor dimerization. Our findings are discussed in view of alternative STAT dimerization models. [less ▲]

Protein fold recognition by prediction-based threading

in Journal of Molecular Biology (1997), 270(3), 471-480

In fold recognition by threading one takes the amino acid sequence of a protein and evaluates how well it fits into one of the known three-dimensional (3D) protein structures. The quality of sequence ... [more ▼]

In fold recognition by threading one takes the amino acid sequence of a protein and evaluates how well it fits into one of the known three-dimensional (3D) protein structures. The quality of sequence-structure fit is typically evaluated using inter-residue potentials of mean force or other statistical parameters. Here, we present an alternative approach to evaluating sequence-structure fitness. Starting from the amino acid sequence we first predict secondary structure and solvent accessibility for each residue. We then thread the resulting one-dimensional (1D) profile of predicted structure assignments into each of the known 3D structures. The optimal threading for each sequence-structure pair is obtained using dynamic programming. The overall best sequence-structure pair constitutes the predicted 3D structure for the input sequence. The method is fine-tuned by adding information from direct sequence-sequence comparison and applying a series of empirical filters. Although the method relies on reduction of 3D information into 1D structure profiles, its accuracy is, surprisingly, not clearly inferior to methods based on evaluation of residue interactions in 3D. We therefore hypothesise that existing 1D-3D threading methods essentially do not capture more than the fitness of an amino acid sequence for a particular 1D succession of secondary structure segments and residue solvent accessibility. The prediction-based threading method on average finds any structurally homologous region at first rank in 29% of the cases (including sequence information). For the 22% first hits detected at highest scores, the expected accuracy rose to 75%. However, the task of detecting entire folds rather than homologous fragments was managed much better; 45 to 75% of the first hits correctly recognised the fold. [less ▲]

Review of: George Lakoff. Moral Politics

in BELL. Belgian Journal of English Language and Literatures (1997), 6

Surface-induced organization of linear molecules on nanostructured polytetrafluoroethylene: Crystalline state of poly[vinylidenefluoride-trifluoroethylene].

in Physical Review. B, Condensed Matter and Materials Physics (1997), 55(6), 3497-3506

Highly crystalline and uniaxial-oriented polytetrafluoroethylene films, nanostructured in one dimension, were used to produce a fully crystalline, thermoreversible morphology in the ferroelectric ... [more ▼]

Highly crystalline and uniaxial-oriented polytetrafluoroethylene films, nanostructured in one dimension, were used to produce a fully crystalline, thermoreversible morphology in the ferroelectric copolymer poly[vinylidenefluoride-trifluoroethylene]. The resulting state is built up of regularly stacked lamellar crystals of about 100 nm thickness and lateral dimensions of about 6 μm. [less ▲]

Saar-Lor-Lux - Die Bedeutung der lokalen grenzüberschreitenden Kooperation für den europäischen Integrationsprozeß.

in Europa Regional (1997)

Cardiac myocytes and fibroblasts contain functional estrogen receptors.

in FEBS letters (1997), 416(1), 107-12

Gender-based differences found in cardiovascular diseases raise the possibility that estrogen may have direct effects on cardiac tissue. Therefore we investigated whether cardiac myocytes and fibroblasts ... [more ▼]

Gender-based differences found in cardiovascular diseases raise the possibility that estrogen may have direct effects on cardiac tissue. Therefore we investigated whether cardiac myocytes and fibroblasts express functional estrogen receptors. Immunofluorescence demonstrated estrogen receptor protein expression in both female and male rat cardiac myocytes and fibroblasts. Nuclear translocation of the estrogen receptor protein was observed after stimulation of cardiomyocytes with 17beta-estradiol (E2). Cells transfected with an estrogen-responsive reporter plasmid showed that treatment with E2 induced a significant increase in reporter activity. Furthermore, E2 induced a significant increase in expression of the estrogen receptors alpha and beta, progesterone receptor and connexin 43 in cardiac myocytes. Cardiac myocytes and fibroblasts contain functional estrogen receptors and estrogen regulates expression of specific cardiac genes. These data suggest that gender-based differences in cardiac diseases may in part be due to direct effects of estrogen on the heart. [less ▲]

Space-charge controlled conduction in low-temperature-grown molecular-beam epitaxial GaAs,

in Applied Physics Letters (1997), 71

Current transport in low-temperature (LT) molecular-beam epitaxial GaAs grown at 200-300 °C on an n+ GaAs substrate is studied by means of current–voltage–temperature characteristics. The resistivity of ... [more ▼]

Current transport in low-temperature (LT) molecular-beam epitaxial GaAs grown at 200-300 °C on an n+ GaAs substrate is studied by means of current–voltage–temperature characteristics. The resistivity of LT GaAs at low electric fields is rho>108 Ohm cm, much higher than resulting from van der Pauw measurements. It is found that the measured resistivity decreases with increasing the LT GaAs thickness. This is explained by space-charge effect in the vicinity of n+/LT GaAs junction and subsequent suppression of hopping conduction in the high-field junction region. [less ▲]

Enhancing the Web's infrastructure: from caching to replication

in IEEE Internet Computing (1997), 1(2), 18-27

Superheavy nuclei in self-consistent nuclear calculations

in Physical Review. C : Nuclear Physics (1997), 56(1), 238-243

The shell structure of superheavy nuclei is investigated within various parametrizations of relativistic and nonrelativistic nuclear mean-field models. The heaviest known even-even nucleus 156 264Hs108 is ... [more ▼]

The shell structure of superheavy nuclei is investigated within various parametrizations of relativistic and nonrelativistic nuclear mean-field models. The heaviest known even-even nucleus 156 264Hs108 is used as a benchmark to estimate the predictive value of the models. From that starting point, doubly magic spherical nuclei are searched in the region Z51102140 and N5134–298. They are found at (Z5114 , N5184), (Z5120 , N5172), or at (Z5126 , N5184), depending on the parametrization. [less ▲]

Alter Wein in neuen Schläuchen? Agenda 21 und Stadtentwicklung -

in Politische Ökologie : die Reihe für Querdenker und Vordenkerinnen (1997), (52), 38-41

Rapid identification of measles virus strains by the heteroduplex mobility assay

in Virus Research (1997), 47(2), 472197-203

The continued endemic presence of measles virus (MV), and the large number of isolates which are made in South Africa each year, demanded the use of a rapid and reliable pre-screening technique to select ... [more ▼]

The continued endemic presence of measles virus (MV), and the large number of isolates which are made in South Africa each year, demanded the use of a rapid and reliable pre-screening technique to select isolates for molecular epidemiological studies by sequence analysis. The heteroduplex mobility assay (HMA) was used to genetically characterize 47 MV isolates collected from three different provinces in South Africa, made between 1986 and 1995. The carboxyl-terminal 590 nt of the nucleocapsid (N) gene - the most variable region of the genome - was amplified by polymerase chain reaction (PCR) and subsequently subjected to HMA analysis for initial genotyping. The results showed three different patterns of heteroduplex formation by gel electrophoresis, representing two distinct wild-type lineages and one group of vaccine-like viruses. Comparison of HMA results with phylogenetic analysis of sequence data for several of the South African MV strains showed a complete correlation of results. The HMA proved to be a useful tool for screening MV isolates for use in molecular epidemiological studies. [less ▲]

Characterization of new proteins found by analysis of short open reading frames from the full yeast genome

in Journal of Yeast and Fungal Research (1997), 13(14), 1363-1374

We have analysed short open reading frames (between 150 and 300 base pairs long) of the yeast genome (Saccharomyces cerevisiae) with a two-step strategy. The first step selects a candidate set of open ... [more ▼]

We have analysed short open reading frames (between 150 and 300 base pairs long) of the yeast genome (Saccharomyces cerevisiae) with a two-step strategy. The first step selects a candidate set of open reading frames from the DNA. sequence based on statistical evaluation of DNA and protein sequence properties. The second step filters the candidate set by selecting open reading frames with high similarity to other known sequences (from any organism). As a result, we report ten new predicted proteins not present in the current sequence databases. These include a new alcohol dehydrogenase, a protein probably related to the cell cycle, as well as a homolog of the prokaryotic ribosomal protein L36 likely to be a mitochondrial ribosomal protein coded in the nuclear genome. We conclude that the analysis of short open reading frames leads to biologically interesting discoveries, even though the quantitative yield of new proteins is relatively low. [less ▲]

Isolation of the Pax9 cDNA from adult human esophagus.

in Mammalian Genome (1997), 8(1), 62-4

Quantitative examination of calcitonin gene-related peptide immunoreactive nerve fibers in the cat knee joint capsule

in Anatomy & Embryology (1997), 195

Color-Sensistive Si-Photodiode Using Porous Silicon Interference Filters

in Japanese Journal of Applied Physics (1997), 36(1997), 24-26

Rezension des Artikels: Neuere Forschungsarbeiten zur Kontaktlinguistik (Plurilingua XIX) von Moelleken, WW. & Weber P.J.

in Tertium Comparationis. Journal für Internationale Bildungsforschung (1997), 4(1), 71-73

Color-Sensitive Photodetector Based on Porous Silicon Superlattices

in Thin Solid Films (1997), 297(1997), 241-244

Measles virus transmission from infected to immune individuals - Implications for measles control and elimination

in South African Medical Journal (1997), 87(12), 1709

A Return to the Dewey-Russell Opposition.

in [Review Essay] Culture & Psychology (1997), 3(1), 99-105

Effects of an acute inflammation on the proportion of CGRP- and SP-containing joint afferents

in Neuroscience Letters (1997), 233

Actions exponentielles et noyaux d'opérateurs

in Travaux Mathématiques (1997), 9

Calcitonin gene-related peptide- and substance P-like immunoreactive fibers in the spermatic nerve and testis of the dog.

in Neuroscience Letters (1997), 235

Gezin en moraal: Gezinsopvoeding als het morele fundament van de samenleving?

in Comenius (1997), 17(4), 275-280

Pax genes and organogenesis.

in BioEssays (1997), 19(9), 755-65

Pax genes are a family of developmental control genes that encode nuclear transcription factors. They are characterized by the presence of the paired domain, a conserved amino acid motif with DNA-binding ... [more ▼]

Pax genes are a family of developmental control genes that encode nuclear transcription factors. They are characterized by the presence of the paired domain, a conserved amino acid motif with DNA-binding activity. Originally, paired-box-containing genes were detected in Drosophila melanogaster, where they exert multiple functions during embryogenesis. In vertebrates, Pax genes are also involved in embryogenesis. Mutations in four out of nine characterized Pax genes have been associated with either congenital human diseases such as Waardenburg syndrome (PAX3), Aniridia (PAX6), Peter's anomaly (PAX6), renal coloboma syndrome (PAX2) or spontaneous mouse mutants (undulated (Pax1), Splotch (Pax3), Small eye (Pax6), Pax2(1)Neu), which all show defects in development. Recently, analysis of spontaneous and transgenic mouse mutants has revealed that vertebrate pax genes are key regulators during organogenesis of kidney, eye, ear, nose, limb muscles, vertebral column and brain. Like their Drosophila counterparts, vertebrate Pax genes are involved in pattern formation during embryogenesis, possibly by determining the time and place of organ initiation or morphogenesis. For most tissues, however, the nature of the primary developmental action of Pax transcription factors remains to be elucidated. One predominant theme is signal transduction during tissue interactions, which may lead to a position-specific regulation of cell proliferation. [less ▲]

Accuracy assessment of recent ocean tide models

in Journal of Geophysical Research (1997), 102(C11), 25173-25194

Fluctuations in GAD65 antibodies after clinical diagnosis of IDDM in young children

in Diabetes Care (1997), 20(4), 642-644

OBJECTIVE - To investigate whether the presence of GAD antibodies at onset of IDDM correlates to a more aggressive rate of β-cell destruction after clinical onset. RESEARCH DESIGN AND METHODS - We studied ... [more ▼]

OBJECTIVE - To investigate whether the presence of GAD antibodies at onset of IDDM correlates to a more aggressive rate of β-cell destruction after clinical onset. RESEARCH DESIGN AND METHODS - We studied GAD antibodies at onset of disease, after 1 year, and after 6 years in 33 consecutively referred children (mean age 8.08, range 1.7-16.3). In a subset of 11 patients, GAD antibodies were studied very frequently. The correlation between GAD antibodies and clinical parameters, including glycosylated hemoglobin, residual insulin secretion, and insulin dosage, was evaluated. RESULTS - GAD antibody titers were highly variable. Four patients became GAD antibody positive weeks to years after clinical onset. Other patients switched between testing positive and negative for GAD antibodies shortly after clinical onset. No correlation was found between the presence of GAD antibodies and the rate of β-cell destruction, but patients with high GAD antibody indexes at onset had significantly higher glycosylated hemoglobin levels. CONCLUSIONS - GAD antibodies at clinical onset do not predict the rate of β-cell destruction in young children with newly diagnosed IDDM. The highly variable GAD antibody levels suggest variation of the autoimmune process. [less ▲]

Une caractérisation différentielle des points de Weierstrass généralisés d'une surface de Riemann compacte de genre g > 1

in Journal de Mathématiques Pures et Appliquées (1997), 76

Human umbilical cord blood-derived eosinophils cultured in the presence of IL-3 and IL-5 respond to fMLP with [Ca2+]i variation and O2- production

in Journal of Immunological Methods (1997), 205(1), 1-9

In the presence of interleukin-3 and interleukin-5, eosinophil precursors from human umbilical cord blood mononuclear cells were regularly differentiated into mature eosinophil-like cells expressing ... [more ▼]

In the presence of interleukin-3 and interleukin-5, eosinophil precursors from human umbilical cord blood mononuclear cells were regularly differentiated into mature eosinophil-like cells expressing normal morphology and cyanide-resistant peroxidase. O2- production and [Ca2+]i rise were measured in these in vitro differentiated eosinophils after fMLP stimulation; with dihydrorhodamine-123 and fura-2, respectively. Umbilical cord blood-derived eosinophils responded to fMLP (0.01 nM to 3 microM) with a concentration-dependent production of O2- (EC50 = 63.1 +/- 17.2 nM; Emax = 71.0 +/- 6.2 pmol/min/10(6) cells). O2- production was correlated with an fMLP concentration-dependent increase in [Ca2+]i (EC50 = 32.5 +/- 14.9 nM; Emax = 200.0 +/- 23.9 nM). These results indicate that human umbilical cord blood-derived eosinophils demonstrate functional characteristics similar to adult human peripheral blood eosinophils after activation by fMLP. Therefore, the large numbers of eosinophils (2-3 x 10(6)/ml cord blood) which can be obtained by culture of human cord blood mononuclear cells may serve as a useful model for future studies which will provide insight into the pathogenesis of diseases associated with eosinophils. [less ▲]

Comment évaluer l’algèbre au 1er degré de l’enseignement secondaire ? Un outil concret pour les enseignants

in Informations Pédagogiques (1997), 34

Review of R.V. Arcilla, For the Love of Perfection.

in Interchange (1997), 28(1), 85-88

Pestalozzi - fermerait-il nos écoles?

in Bulletin du Centre de Documentation et de Recherche Pestalozzi (1997), 22

Revêtements de courbes elliptiques à multiplication complexe par des courbes hyperelliptiques et sommes de caractères

in Journal of Number Theory (1997), 64(2), 165-182

Trends in service delivery: Psychological practice in rehabilitation settings

in Rehabilitation Outllook (1997)

Capacity Utilization and Market Power

in Journal of Economic Dynamics and Control (1997), 22

We propose a theoretical macroeconomic model where capacity underutilization follows from idiosyncratic demand uncertainty at the time monopolistic firms must choose their productive capacity. After their ... [more ▼]

We propose a theoretical macroeconomic model where capacity underutilization follows from idiosyncratic demand uncertainty at the time monopolistic firms must choose their productive capacity. After their investment decision, firms facing a low demand will typically prefer to run excess capacities rather than reduce their profit margin; firms at full capacity will respond to demand fluctuations solely by price adjustments. We show that the proportion of firms with idle capacities influences crucially the short-run response of the economy to exogenous disturbances and, in particular, the relative importance of price and quantity adjustments. [less ▲]

The role of actin binding proteins in epithelial morphogenesis: models based upon Listeria movement.

in Biophysical chemistry (1997), 68(1-3), 73-82

We summarize recent findings on the organization of the protein actin in eucaryotic cells. In particular we focus on how actin can be used to generate a vectorial force that is required for cell movement ... [more ▼]

We summarize recent findings on the organization of the protein actin in eucaryotic cells. In particular we focus on how actin can be used to generate a vectorial force that is required for cell movement. These forces arise from protein molecules that recruit actin to the plasma membrane in such a manner that actin filaments extend outward from the cell body. This type of actin dependent force generation has been described in a nucleation-release model, which is one of several models currently being tested to explain actin dependent cell movement. Data in support of this model has arisen unexpectedly from studies of an intracellular bacteria, Listeria monocytogenes. This bacteria uses actin to propel itself during infection of eucaryotic cells. By studying Listeria movement, the roles of several eucaryotic actin interacting proteins have been identified. One of these is zyxin, a human protein that shares important structural and possibly functional properties with ActA, an actin dependent force generating protein of Listeria. We intend to test the function of these and other actin interacting proteins in a simplified system that should facilitate precise measurement of their properties of force generation in vitro. [less ▲]

Logistik in Unternehmenspolitik und Planung. Stufenkonzepte zwischen privat und öffentlich, funktionaler und ökologischer Modernisierung.

in RaumPlanung (1997), (76), 45-49

Der Grossvater Pestalozzis als pietistisch-pädagogischer Vermittler? Einleitung

in Neue Pestalozzi-Blätter (1997), 3(1), 28-29

World Wide Web caching: the application-level view of the Internet

in IEEE Communications Magazine (1997), 35(6), 170-178

0.1 µm T-gate Al-free InP/InGaAs/InP pHEMTs for W-Band Applications Using a Nitrogen Carrier for LP-MOCVD Growth

in IEEE Electron Device Letters (1997), 18

We report on the dc and RF performance of HEMT’s based on the Al-free material system InP/InGaAs/InP. These structures were grown by LP-MOCVD using a nitrogen carrier. The influence of gate length and ... [more ▼]

We report on the dc and RF performance of HEMT’s based on the Al-free material system InP/InGaAs/InP. These structures were grown by LP-MOCVD using a nitrogen carrier. The influence of gate length and channel composition on the performance of these devices is investigated.We demonstrate that optimum dc and RF performance using highly strained channels can be obtained only if additional composite channels are grown. The cutoff frequencies fT =160 GHz and fmax=260 GHz for a 0.1- um T-gate device indicate the suitability of our devices for W-Band applications. [less ▲]

Antagonistic interactions between FGF and BMP signaling pathways: a mechanism for positioning the sites of tooth formation.

in Cell (1997), 90(2), 247-55

Vertebrate organogenesis is initiated at sites that are often morphologically indistinguishable from the surrounding region. Here we have identified Pax9 as a marker for prospective tooth mesenchyme prior ... [more ▼]

Vertebrate organogenesis is initiated at sites that are often morphologically indistinguishable from the surrounding region. Here we have identified Pax9 as a marker for prospective tooth mesenchyme prior to the first morphological manifestation of odontogenesis. We provide evidence that the sites of Pax9 expression in the mandibular arch are positioned by the combined activity of two signals, one (FGF8) that induces Pax9 expression and the other (BMP2 and BMP4) that prevents this induction. Thus it appears that the position of the teeth is determined by a combination of two different types of signaling molecules produced in wide but overlapping domains rather than by a single localized inducer. We suggest that a similar mechanism may be used for specifying the sites of development of other organs. [less ▲]

Psychoneuroimmunological correlates of persiting pain in patients who underwent discectomy

in Neuroscience Letters (1997), 237(2), 65-68

Structural and functional similarities between the human cytoskeletal protein zyxin and the ActA protein of Listeria monocytogenes.

in Journal of cell science (1997), 110 ( Pt 16)

The intracellular bacterial parasite Listeria monocytogenes produces ActA protein at its surface to facilitate the localized assembly of actin-filled comets that are required for movement. The ... [more ▼]

The intracellular bacterial parasite Listeria monocytogenes produces ActA protein at its surface to facilitate the localized assembly of actin-filled comets that are required for movement. The organization of actin in Listeria comets shows striking similarity to the organization of actin at the plasma membrane of mammalian cells. Therefore we examined the possibility that an ActA-like protein is present in mammalian cells. By using antibodies directed against ActA, we identified zyxin as an ActA related protein in a number of cell types. We compared the functions of ActA and zyxin by transient expression of variants tagged with an inner plasma membrane localization sequence (a CAAX box). Targeting of the proline rich domain of zyxin to the plasma membrane disrupts the actin cytoskeleton and cell shape in a manner similar to that which occurs with membrane-targeted ActA sequences. A chimeric protein composed of the N-terminal domain of ActA fused to the N-terminal and central domains of zyxin induced a full ActA response in cells. Furthermore, zyxin and ActA exhibit common protein partners in vitro. On the basis of the shared properties of zyxin and ActA, we propose that zyxin enhances actin organizing activity in mammalian cells. [less ▲]

Effects of moexiprilat on oestrogen-stimulated cardiac fibroblast growth.

in British journal of pharmacology (1997), 121(7), 1350-4

1. The effects of 2-2-(1-(ethoxycarbonyl)-3-phenylpropyl)-[amino-oxopropyl]-6,7-dimethoxy- 1,2,3,4-tetrahydroisoquinoline-3 carboxylic acid (moexiprilat), 17beta-oestradiol (E2), oestrone (ES) and ... [more ▼]

1. The effects of 2-2-(1-(ethoxycarbonyl)-3-phenylpropyl)-[amino-oxopropyl]-6,7-dimethoxy- 1,2,3,4-tetrahydroisoquinoline-3 carboxylic acid (moexiprilat), 17beta-oestradiol (E2), oestrone (ES) and angiotensin II (AII) on growth and activation of oestrogen receptors and the immediate-early gene egr-1 were investigated in neonatal rat cardiac fibroblasts of female and male origin. 2. In BrdU proliferation assays, oestrone (10(-7)- 10(-9) M) stimulated cardiac fibroblast growth in a concentration-dependent fashion (maximum at 10(-7) M, 4.0 fold +/- 0.14 in female and 3.1 fold +/- 0.06 in male cells, n=9, P<0.05), while E2 (10(-7)-10(-9) M) had no effect. Moexiprilat (10(-7)M) completely inhibited oestrone-induced cardiac fibroblast growth. 3. Angiotensin II (10(-7) M) induced cardiac fibroblast growth (female 4.1 fold +/- 0.1/male 3.9 fold +/- 0.2; n=9, P<0.05). Angiotensin II induced oestrogen receptor (maximum 21.8 fold at 60 min) and egr-1 (maximum 47.5 fold at 60 min) expression in a time-dependent fashion. 4. In immunoblot experiments, oestrogen activated oestrogen receptor (ES: 12.8 fold +/- 2.0; E2: 14.7 fold +/- 4.9; n=3, P<0.05) and egr-1 (ES: 5.1 fold, +/- 0.24; E2: 3.8 fold, +/- 0.25; n=3, P<0.05) expression. The induction of oestrogen receptor and egr-1 protein expression was time-dependent and inhibited by moexiprilat. 5. Our results show that oestrone and 17beta-oestradiol reveal a significant difference in their potential to activate cardiac fibroblast growth in female and male cells and that oestrone-stimulated growth is inhibited by moexiprilat. The inhibition of oestrone-stimulated cardiac fibroblast growth by moexiprilat may contribute to the beneficial effects seen in postmenopausal women with hypertensive heart disease treated with ACE inhibitors. [less ▲]

Segment-specific expression of the gap junction gene connexin 31 during hindbrain development

in Development Genes & Evolution (1997), (207), 359-361

Organisation of the biosynthetic gene cluster for rapamycin in Streptomyces hygroscopicus: analysis of the enzymatic domains in the modular polyketide synthase

in Gene (1996), 169(1), 9-16

The three giant multifunctional polypeptides of the rapamycin (Rp)-producing polyketide synthase (RAPS1, RAPS2 and RAPS3) have recently been shown to contain 14 separate sets, or modules, of enzyme ... [more ▼]

The three giant multifunctional polypeptides of the rapamycin (Rp)-producing polyketide synthase (RAPS1, RAPS2 and RAPS3) have recently been shown to contain 14 separate sets, or modules, of enzyme activities, each module catalysing a specific round of polyketide chain extension. Detailed sequence comparison between these protein modules has allowed further characterisation of aa that may be important in catalysis or specificity. The acyl-carrier protein (ACP), beta-ketoacyl-ACP synthase (KS) and acyltransferase (AT) domains (the core domains) have an extremely high degree of mutual sequence homology. The KS domains in particular are almost perfect repeats over their entire length. Module 14 shows the least homology and is unique in possessing only core domains. The enoyl reductase (ER), beta-ketoacyl-ACP reductase (KR) and dehydratase (DH) domains are present even in certain modules where they are not apparently required. Four DH domains can be recognised as inactive by characteristic deletions in active site sequences, but for two others, and for KR and ER in module 3, the sequence is not distinguishable from that of active counterparts in other modules. The N terminus of RAPS1 contains a novel coenzyme A ligase (CL) domain that activates and attaches the shikimate-derived starter unit, and an ER activity that may modify the starter unit after attachment. The sequence comparison has revealed the surprisingly high sequence similarity between inter-domain 'linker' regions, and also a potential amphipathic helix at the N terminus of each multienzyme subunit which may promote dimerisation into active species. [less ▲]

Sur une conjecture sur les points de torsion rationnels des Jacobiennes de courbes

in Journal für die Reine und Angewandte Mathematik (1996), 473

Dagmar Schifferli: Anna Pestalozzi-Schulthess. Ihr Leben mit Heinrich Pestalozzi.

in Bulletin der Schweizerischen Gesellschaft für die Erforschung des 18. Jahrhunderts (1996), 9

Jugend und Politik

in Jugendhilfe Report (1996), (2), 35-35

Endothelin-1 does not modulate O2.release and [Ca(2+)]i variations in resting or differentiated HL-60 cells

in Fundamental and Clinical Pharmacology (1996), 10(1), 28-32

Endothelin-1 (ET-1) by itself was not an effective stimulus for inducing superoxide (O2.) generation in human resting or DMSO-differentiated neutrophil-like HL-60 cells. ET-1 (0.01-100 nM) was not able to ... [more ▼]

Endothelin-1 (ET-1) by itself was not an effective stimulus for inducing superoxide (O2.) generation in human resting or DMSO-differentiated neutrophil-like HL-60 cells. ET-1 (0.01-100 nM) was not able to modulate O2. generation stimulated by the chemotactic peptide N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP, EC50 = 4.24 +/- 1.63 nM in the absence and 3.16 +/- 1.95 nM in the presence of ET-1). Neither did ET-1 (0.01-100 nM) promote the mobilization of intracellular calcium ions or modulate fMLP-induced [Ca(2+)]i increase in this model of human neutrophils. Phosphoramidon, a neutral endopeptidase inhibitor, was not able to reveal any biological (O2.) or biochemical ([Ca(2+)]i response to ET-1 in the absence or in the presence of fMLP in these cells. These results indicate that DMSO-differentiated neutrophil-like HL-60 cells are not sensitive to ET-1 in terms of O2. generation or [Ca(2+)]i variations. [less ▲]

Umweltmanagement. Neue Ansätze durch EG-Öko-Audit und DIN-ISO 14001.

in Internationales Verkehrswesen (1996), 48(9), 39-44