Search results for "Complement"
showing 10 items of 2113 documents
T-DNA insertion alters the terpenoid content composition and bioactivity of transgenic Artemisia annua.
2014
In this study, the interference of T-DNA insertion upon Agrobacterium-mediated transformation on the biochemical expression of the host genome is discussed. Plant extracts of transgenic Artemisia annua L. with or without an overexpressed farnesyl pyrophosphate synthase gene have been investigated for their bioactivity and metabolic profile in comparison with wild type A. annua. The highest antimicrobial activity against Staphylococcus aureus, Bacillus subtilis and Candida albicans was observed in the T253 transgenic lines. Moreover, the crude extract from T253 showed higher antimalarial activity against the Plasmodium faciparum K1 strain than those of the others. The terpenoid constituents…
The disintegrin ADAM9 indirectly contributes to the physiological processing of cellular prion by modulating ADAM10 activity
2005
The cellular prion protein (PrP(c)) is physiologically cleaved in the middle of its 106-126 amino acid neurotoxic region at the 110/111 downward arrow112 peptidyl bond, yielding an N-terminal fragment referred to as N1. We recently demonstrated that two disintegrins, namely ADAM10 and ADAM17 (TACE, tumor necrosis factor alpha converting enzyme) participated in both constitutive and protein kinase C-regulated generation of N1, respectively. These proteolytic events were strikingly reminiscent of those involved in the so-called "alpha-secretase pathway" that leads to the production of secreted sAPPalpha from betaAPP. We show here, by transient and stable transfection analyses, that ADAM9 also…
Arginine kinase in the demosponge Suberites domuncula:regulation of its expression and catalytic activity by silicic acid
2005
SUMMARY In Demospongiae (phylum Porifera) the formation of the siliceous skeleton,composed of spicules, is an energetically expensive reaction. The present study demonstrates that primmorphs from the demosponge Suberites domuncula express the gene for arginine kinase after exposure to exogenous silicic acid. The deduced sponge arginine kinase sequence displays the two characteristic domains of the ATP:guanido phosphotransferases; it can be grouped to the `usual' mono-domain 40 kDa guanidino kinases (arginine kinases). Phylogenetic studies indicate that the metazoan guanidino kinases evolved from this ancestral sponge enzyme; among them are also the `unusual'two-domain 80 kDa guanidino kinas…
Ubiquitin and ubiquitination in cells from the marine sponge Geodia cydonium.
1994
Marine sponges, e.g. Geodia cydonium, have been intensively used to investigate the biochemical and molecular biological basis of cell-cell- and cell-matrix adhesion. It has been shown that a family of galactose-specific lectins, which are present in the extracellular space of G. cydonium, is a main component involved in cell-matrix adhesion in the sponge system. In the present study it is outlined that the purified 16-kDa lectin-1 binds to a 67-kDa membrane-associated protein. This lectin-binding protein undergoes mono- and diubiquitination after incubation of dissociated sponge cells with the homologous aggregation factor (AF), a molecule involved in cell-cell adhesion. The gene coding fo…
Cloning and expression of the putative aggregation factor from the marine sponge Geodia cydonium.
2001
Sponges (phylum Porifera) have extensively been used as a model system to study cell-cell interaction on molecular level. Recently, we identified and cloned the putative aggregation receptor (AR) of the sponge Geodia cydonium, which interacts in a heterophilic way with the aggregation factor (AF) complex. In the present study, antibodies against this complex have been raised that abolish the adhesion function of the enriched sponge AF, the AF-Fraction 6B. Using this antibody as a tool, a complete 1.7 kb long cDNA, GEOCYAF, could be isolated from a cDNA library that encodes the putative AF. Its deduced aa sequence in the N-terminal section comprises high similarity to amphiphysin/BIN1 sequen…
Identification of target antigen for SLA/LP autoantibodies in autoimmune hepatitis.
2000
Summary Background Autoantibodies are a hallmark of autoimmune hepatitis, but most are not disease specific. Autoantibodies to soluble liver antigen (SLA) and to liver and pancreas antigen (LP) have been described as disease specific, occurring in about 30% of all patients with autoimmune hepatitis, but no standardised assays are available. Methods We tested 2000 serum samples from patients with various liver diseases and controls for SLA autoantibodies by inhibition ELISA. Serum samples positive for SLA antibodies were used for immunoscreening of cDNA expression libraries. Identified clones were tested against a panel of serum samples positive for SLA and LP autoantibodies and control seru…
Digital image processing for rapid analysis of differentially expressed transcripts on high-density cDNA arrays.
1999
Usage of filter arrays is becoming increasingly attractive for many research laboratories involved in determination of gene-expression profiles. However, analysis of numerous spots, representing genes or partial gene sequences (ESTs), is still tedious work involving the ordered analysis of vast amounts of numerical tabular data. We present a rapid and efficient method for the visual identification of differentially expressed targets on high-density cDNA filter arrays using standard laboratory equipment and standard software, which is available for free. The method we introduce provides an inexpensive alternative, and no changes in the experimental set up are required. Our results were veri…
Contribution of CYP3A5 to the in vitro hepatic clearance of tacrolimus.
2005
Abstract Background: Tacrolimus is metabolized predominantly to 13-O-demethyltacrolimus in the liver and intestine by cytochrome P450 3A (CYP3A). Patients with high concentrations of CYP3A5, a CYP3A isoenzyme polymorphically produced in these organs, require higher doses of tacrolimus, but the exact mechanism of this association is unknown. Methods: cDNA-expressed CYP3A enzymes and a bank of human liver microsomes with known CYP3A4 and CYP3A5 content were used to investigate the contribution of CYP3A5 to the metabolism of tacrolimus to 13-O-demethyltacrolimus as quantified by liquid chromatography–tandem mass spectrometry. Results: Demethylation of tacrolimus to 13-O-demethyltacrolimus was …
Myosin VIIa, harmonin and cadherin 23, three Usher I gene products that cooperate to shape the sensory hair cell bundle
2002
Deaf-blindness in three distinct genetic forms of Usher type I syndrome (USH1) is caused by defects in myosin VIIa, harmonin and cadherin 23. Despite being critical for hearing, the functions of these proteins in the inner ear remain elusive. Here we show that harmonin, a PDZ domain-containing protein, and cadherin 23 are both present in the growing stereocilia and that they bind to each other. Moreover, we demonstrate that harmonin b is an F-actin-bundling protein, which is thus likely to anchor cadherin 23 to the stereocilia microfilaments, thereby identifying a novel anchorage mode of the cadherins to the actin cytoskeleton. Moreover, harmonin b interacts directly with myosin VIIa, and i…
Origin of the metazoan bodyplan: characterization and functional testing of the promoter of the homeobox gene EmH-3 from the freshwater sponge Ephyda…
1998
Porifera [sponges] represent the lowest metazoan phylum, probably already existing prior to the 'Cambrian explosion'. Based on amino acid sequences deduced from cDNAs that code for structural proteins, the monophyly of Metazoa was established. Now we analyzed for the first time a promoter of a sponge gene for its activity in a heterologous cell system from higher Metazoa. The promoter of the homeobox gene EmH-3 was cloned and sequenced from a genomic library of the freshwater sponge Ephydatia muelleri. For the determination of functional promoter activity, transient transfection experiments in mouse NIH 3T3 cells were performed; the promoter was fused with the luciferase reporter gene. The …