Search results for " Complementary"
showing 10 items of 280 documents
Diversity of stonefly hexamerins and implication for the evolution of insect storage proteins
2007
Hexamerins are large storage proteins of insects in the 500 kDa range that evolved from the copper-containing hemocyanins. Hexamerins have been found at high concentration in the hemolymph of many insect taxa, but have remained unstudied in relatively basal taxa. To obtain more detailed insight about early hexamerin evolution, we have studied hexamerins in stoneflies (Plecoptera). Stoneflies are also the only insects for which a functional hemocyanin is known to co-occur with hexamerins in the hemolymph. Here, we identified hexamerins in five plecopteran species and obtained partial cDNA sequences from Perla marginata (Perlidae), Nemoura sp. (Nemouridae), Taeniopteryx burksi (Taeniopterygid…
Molecular characterization of hemocyanin and hexamerin from the firebrat Thermobia domestica (Zygentoma).
2008
Hexapods possess a tracheal system that enables the transport of oxygen to the inner organs. Although respiratory proteins have been considered unnecessary in most Hexapoda for this reason, we recently showed the presence of a functional hemocyanin in the stonefly Perla marginata. Here we report the identification and molecular characterization of a hemocyanin from Zygentoma (Thysanura). We obtained the full length cDNA of two distinct subunit types from the firebrat Thermobia domestica, and partial sequences of the orthologs from the silverfish Lepisma saccharina. The native T. domestica hemocyanin subunits both consist of 658 amino acids, but a signal peptide for transmembrane transport i…
A respiratory hemocyanin from an insect.
2004
Insects possess an elaborate tracheal system that enables transport of gaseous oxygen from the atmosphere directly to the inner organs. Therefore, the presence of specialized oxygen-transport proteins in the circulatory system of insects has been considered generally unnecessary. Here, we show for the first time, to our knowledge, the presence of an ancestral and functional hemocyanin (Hc) in an insect. In the hemolymph of nymphs and adults of the stonefly Perla marginata , a hexameric Hc was identified, which consists of two distinct subunit types of 659 and 655 amino acids. P. marginata Hc displays cooperative oxygen binding with a moderately high oxygen affinity [(half-saturation pressu…
Molecular cloning and expression of Tenebrio molitor ultraspiracle during metamorphosis and in vivo induction of its phosphorylation by 20-hydroxyecd…
2000
Using a RT-PCR approach, the Tenebrio molitor homologue of Drosophila Ultraspiracle (TmUSP) was characterized. Its DNA binding domain shows a degree of identity with those of the other insect USPs. However, the ligand binding domain is closer to those of retinoid X receptors. Using an antibody raised against DmUSP, Western blot analysis of proteins from epidermis and other tissues revealed five immunoreactive bands, corresponding to different phosphorylated forms of a unique polypeptide, as shown by lambda-phosphatase treatment. The nuclear form of TmUSP seems unphosphorylated. An in vivo 20-hydroxyecdysone treatment increases considerably and rapidly the phosphorylated forms of TmUSP. This…
Analysis of expression of an alternative La (SS-B) cDNA and localization of the encoded N- and C-terminal peptides
1997
AbstractA deletion of an (A)-residue was detected in a cDNA encoding for the nuclear autoantigen La/SS-B. The cDNA was recently isolated from a cDNA library made from peripheral blood lymphocytes of a patient with primary Sjögren's Syndrome. The region, where the deletion occurred, represents a hot spot region in the La gene(s). It leads to a frame shift mutation and a premature stop codon eleven amino acids downstream of the deletion site within one of the protease sensitive regions of the La protein. In spite of the frame shift mutation expression of full length La protein occurred efficiently in E. coli. Full length La protein was also made in SF9 cells infected with recombinant baculovi…
Isolation and cloning of a C-type lectin from the hexactinellid sponge Aphrocallistes vastus: a putative aggregation factor
2001
Among the sponges (Porifera), the oldest group of metazoans in phylogenetic terms, the Hexactinellida is considered to have diverged earliest from the two other sponge classes, the Demospongiae and Calcarea. The Hexactinellida are unusual among all Metazoa in possessing mostly syncytial rather than cellular tissues. Here we describe the purification of a cell adhesion molecule with a size of 34 kDa (in its native form; 24 kDa after deglycosylation) from the hexactinellid sponge Aphrocallistes vastus. This adhesion molecule was previously found to agglutinate preserved cells and membranes in a non-species-specific manner (Müller, W. E. G., Zahn, R. K, Conrad, J., Kurelec, B., and Uhlenbruck,…
Neuroglobins from the Zebrafish Danio rerio and the Pufferfish Tetraodon nigroviridis
2001
Neuroglobin is a recently discovered respiratory, porphyrin-containing protein that is expressed in the brain of mouse and man. Here we show that neuroglobin is also present in the teleost fish. Complete cDNA sequences are reported from the pufferfish Tetraodon nigroviridis and the zebrafish Danio rerio. In addition, the neuroglobin gene of T. nigroviridis was sequenced, demonstrating the conservation of the B12.2, E11.0 and G7.0 introns plus the presence of an additional intron in the 5' noncoding region. The fish neuroglobins each comprise 159 amino acids and are 84.3% identical. Phylogenetic analyses show a basal position of the neuroglobins within the metazoan globin tree. An enhanced a…
An insect juvenile hormone-specific epoxide hydrolase is related to vertebrate microsomal epoxide hydrolases.
1996
Abstract We describe the first cDNA sequence encoding a juvenile hormone-specific epoxide hydrolase from an insect. A full-length cDNA clone revealed a 462-amino-acid open reading frame encoding an amino acid sequence with 44% identity and 64% similarity to human microsomal epoxide hydrolase. All residues in the catalytic triad (residues Asp 227 -His 428 -Asp 350 in the M. sexta protein) were present, as was the conserved Trp 154 corresponding to the oxyanion hole. The surprising similarity of insect juvenile hormone epoxide hydrolase to vertebrate microsomal epoxide hydrolases, coupled with the ancient lineage of the epoxide hydrolases and haloalkane dehalogenases, suggests that this catab…
Cloning and sequencing of the cDNA encoding human glutaredoxin.
1994
Glutaredoxin (thioltransferase) is a small, heat-stable protein, which is involved in thiol/disulfide exchange reactions. We have isolated a cDNA that encodes glutaredoxin from a human brain cDNA library. The encoded protein contains 106 amino acids with a calculated molecular mass of 11.76 kDa and an isoelectric point of 8.09. The amino acid sequence deduced from the cDNA is more than 80% identical to those of other mammalian glutaredoxins.
A novel member of an ancient superfamily: sponge (Geodia cydonium, Porifera) putative protein that features scavenger receptor cysteine-rich repeats
1997
Proteins featuring scavenger receptor cysteine-rich (SRCR) domains are prominent receptors known from vertebrates and from one phylum of invertebrates, the echinoderms. In the present study we report the first putative SRCR protein from the marine sponge Geodia cydonium (Porifera), a member of the lowest phylum of contemporary Metazoans. Two forms of SRCR molecules were characterized, which apparently represent alternative splicing of the same transcript. The long putative SRCR protein, of 1536 aa, features twelve SRCR repeats, a C-terminal transmembrane domain and a cytoplasmic tail. The sequence of the short form is identical with the long form except that it lacks a coding region near th…