Search results for " Complement"
showing 10 items of 753 documents
Phylogenetic Position of the Hexactinellida Within the Phylum Porifera Based on the Amino Acid Sequence of the Protein Kinase C from Rhabdocalyptus d…
1998
Recent analyses of genes encoding proteins typical for multicellularity, especially adhesion molecules and receptors, favor the conclusion that all metazoan phyla, including the phylum Porifera (sponges), are of monophyletic origin. However, none of these data includes cDNA encoding a protein from the sponge class Hexactinellida. We have now isolated and characterized the cDNA encoding a protein kinase C, belonging to the C subfamily (cPKC), from the hexactinellid sponge Rhabdocalyptus dawsoni. The two conserved regions, the regulatory part with the pseudosubstrate site, the two zinc fingers, and the C2 domain, as well as the catalytic domain were used for phylogenetic analyses. Sequence al…
Isolation and characterization of a cDNA encoding a potential morphogen from the marine sponge Geodia cydonium that is conserved in higher metazoans.
1998
Species belonging to the lowest metazoan phylum, the sponges (Porifera), exhibit a surprisingly complex and multifaceted Bauplan (body plan). Recently, key molecules have been isolated from sponges which demonstrate that the cells of these animals are provided with characteristic metazoan adhesion and signal transduction molecules, allowing tissue formation. In order to understand which factors control the spatial organization of these cells in the sponge body plan, we screened for a cDNA encoding a soluble modulator of the behaviour of endothelial cells. A cDNA encoding a putative protein, which is highly similar to the human and mouse endothelial monocyte-activating polypeptide (EMAP) II …
A hemocyanin from the Onychophora and the emergence of respiratory proteins
2002
The velvet worms (Onychophora) are considered living fossils and are closely related to the Euarthropoda. Onychophora possess a tracheal system for respiratory function, but oxygen-transport proteins have been considered unnecessary. Here, we show that the hemolymph of the Epiperipatus sp. (Onychophora: Peripatidae) contains an arthropod-type hemocyanin, demonstrating that such protein exists outside the Euarthropoda. Thus, the evolution of oxygen carriers preceded the divergence of the Onychophora and Euarthropoda and was most likely linked to the evolution of an efficient circulatory system in a low-oxygen environment. The cDNA of the Epiperipatus hemocyanin subunit comprises 2,287 bp an…
Expression of a plant serine O-acetyltransferase inSaccharomyces cerevisiae confers osmotic tolerance and creates an alternative pathway for cysteine…
2004
Screening of a sugar beet (Beta vulgaris cv. Dita) cDNA library for clones able to confer osmotic tolerance to the osmosensitive gpd1 mutant of Saccharomyces cerevisiae identified a novel serine O-acetyltransferase (BvSAT; EC 2.3.1.30). This enzyme is involved in cysteine biosynthesis in plants and bacteria, producing O-acetylserine, which is converted into cysteine in a reaction catalysed by O-acetylserine sulphydrylase (EC 4.2.99.8). This pathway is not conserved in yeast, where cysteine is synthesized in a four-step pathway starting with homoserine and having O-acetylhomoserine, homocysteine and cystathionine as intermediates. Expression of BvSAT in yeast takes advantage of the activity …
Key Disulfide Bonds in an Insect Hormone Binding Protein: cDNA Cloning of a Juvenile Hormone Binding Protein of Heliothis virescens and Ligand Bindin…
1995
The hemolymph juvenile hormone binding protein (JHBP) from the early fifth instar larvae of Heliothis virescens (Lepidoptera, Noctuidae) has been purified, and three cDNA clones for this protein have been isolated from a fat body cDNA library constructed in bacteriophage λZAP XR. The deduced amino acid sequence of the full-length clone predicts a mature protein consisting of 224 residues, a molecular mass of 24 976 Da, and a p/ of 5.29. Comparison of the amino acid sequence to that of the previously described JHBP from Manduca sexta shows 51 % overall identity with highly conserved N- and C-terminal regions. One of the three clones bound photoactivatable analogs of juvenile hormones with mu…
Identification of a gene overexpressed in aphids reared under short photoperiod.
2003
Most aphids develop a cyclic parthenogenesis life-cycle. After several generations of viviparously produced parthenogenetic females, follows a single annual generation of sexual individuals, usually in autumn, that mate and lay the sexual eggs. Shortening of photoperiod at the end of the summer (together with temperature) is a key factor inducing the sexual response. Currently no genes involved in the cascade of events that lead to the appearance of sexual forms have been reported. After a Differential Display RT-PCR survey performed on Acyrthosiphon pisum aphids, we identified a gene that is overexpressed in aphids reared under short photoperiod conditions that induce sexuality in this spe…
γ-Tubulin in Barley and Tobacco: Sequence Relationship and RNA Expression Patterns in Developing Leaves during Mitosis and Post-Mitotic Growth
2002
gamma-Tubulin is typically associated with microtubule organising centres, such as the centrosome, and appears to mediate microtubule nucleation. Centrosomes are usually not found in higher plants, but active genes homologous to gamma-tubulin have been identified in the plant kingdom, including the angiosperms Arabidopsis, maize and rice. We have isolated and characterised gamma-tubulin cDNA sequences of two further angiosperm species, barley and tobacco. Sequence comparison revealed a phylogenetic tree with distinct clusters corresponding to the systematic position of the species. Furthermore, domains, thought to be exposed in the folded protein and to be candidates for interaction with as…
Putative phenoloxidases in the tunicate Ciona intestinalis and the origin of the arthropod hemocyanin superfamily.
2003
In addition to the respiratory copper-containing proteins for which it is named, the arthropod hemocyanin superfamily also includes phenoloxidases and various copperless storage proteins (pseudo-hemocyanins, hexamerins and hexamerin receptors). It had long been assumed that these proteins are restricted to the arthropod phylum. However, in their analysis of the predicted genes in the Ciona intestinalis (Urochordata:Tunicata) genome, Dehal et al. (Science 298:2157–2167) proposed that the sea squirt lacks hemoglobin but uses hemocyanin for oxygen transport. While there are, nevertheless, four hemoglobin genes present in Ciona, we have identified and cloned two cDNA sequences from Ciona that i…
Rat adrenoleukodystrophy-related (ALDR) gene: full-length cDNA sequence and new insight in expression.
2001
X-linked adrenoleukodystrophy (X-ALD) is an inherited demyelinating disorder due to mutations in the ALD gene, which encodes a peroxisomal ABC half-transporter (ALDP). It has been suggested that ALDP assembles with ALDRP (adrenoleukodystrophy-related protein), a close homologous half-transporter, to form a functional heterodimer. For the first time full-length ALDRP cDNA (5.5 kb) was cloned, and 5' and 3' RACE analysis revealed that alternative usage of polyadenylation sites generates the two transcripts of 3.0 and 5.5 kb observed in the rat in Northern blot analysis. Southern blotting and chromosomal mapping demonstrated one ALDR locus in the rat genome. Characterisation of the 3' flanking…
Acquisition of Structure-guiding and Structure-forming Properties during Maturation from the Pro-silicatein to the Silicatein Form
2012
Silicateins are the key enzymes involved in the enzymatic polycondensation of the inorganic scaffold of the skeletal elements of the siliceous sponges, the spicules. The gene encoding pro-silicatein is inserted into the pCold TF vector, comprising the gene for the bacterial trigger factor. This hybrid gene is expressed in Escherichia coli and the synthesized fusion protein is purified. The fusion protein is split into the single proteins with thrombin by cleavage of the linker sequence present between the two proteins. At 23 °C, the 87 kDa trigger factor-pro-silicatein fusion protein is cleaved to the 51 kDa trigger factor and the 35 kDa pro-silicatein. The cleavage process proceeds and res…