Search results for " Complementary"
showing 10 items of 280 documents
Identification of novel peroxisome proliferator-activated receptor alpha (PPARalpha) target genes in mouse liver using cDNA microarray analysis.
2001
Peroxisome proliferators, which function as peroxisome proliferator-activated receptor-alpha (PPARalpha) agonists, are a group of structurally diverse nongenotoxic hepatocarcinogens including the fibrate class of hypolipidemic drugs that induce peroxisome proliferation in liver parenchymal cells. Sustained activation of PPARalpha by these agents leads to the development of liver tumors in rats and mice. To understand the molecular mechanisms responsible for the pleiotropic effects of these agents, we have utilized the cDNA microarray to generate a molecular portrait of gene expression in the liver of mice treated for 2 weeks with Wy-14,643, a potent peroxisome proliferator. PPARalpha activa…
Digitalis purpurea P5 beta R2, encoding steroid 5 beta-reductase, is a novel defense-related gene involved in cardenolide biosynthesis.
2009
The stereospecific 5 beta-reduction of progesterone is a required step for cardiac glycoside biosynthesis in foxglove plants. Recently, we have isolated the gene P5 beta R, and here we investigate the function and regulation of P5 beta R2, a new progesterone 5 beta-reductase gene from Digitalis purpurea. P5 beta R2 cDNA was isolated from a D. purpurea cDNA library and further characterized at the biochemical, structural and physiological levels. Like P5 beta R, P5 beta R2 catalyzes the 5 beta-reduction of the Delta(4) double bond of several steroids and is present in all plant organs. Under stress conditions or on treatment with chemical elicitors, P5 beta R expression does not vary, wherea…
Molecular dissection of human Argonaute proteins by DNA shuffling.
2013
A paramount task in RNA interference research is to decipher the complex biology of cellular effectors, exemplified in humans by four pleiotropic Argonaute proteins (Ago1-Ago4). Here, we exploited DNA family shuffling, a molecular evolution technology, to generate chimeric Ago protein libraries for dissection of intricate phenotypes independently of prior structural knowledge. Through shuffling of human Ago2 and Ago3, we discovered two N-terminal motifs that govern RNA cleavage in concert with the PIWI domain. Structural modeling predicts an impact on protein rigidity and/or RNA-PIWI alignment, suggesting new mechanistic explanations for Ago3's slicing deficiency. Characterization of hybrid…
alpha 11beta 1 integrin recognizes the GFOGER sequence in interstitial collagens.
2002
The integrins alpha(1)beta(1), alpha(2)beta(1), alpha(10)beta(1), and alpha(11)beta(1) are referred to as a collagen receptor subgroup of the integrin family. Recently, both alpha(1)beta(1) and alpha(2)beta(1) integrins have been shown to recognize triple-helical GFOGER (where single letter amino acid nomenclature is used, O = hydroxyproline) or GFOGER-like motifs found in collagens, despite their distinct binding specificity for various collagen subtypes. In the present study we have investigated the mechanism whereby the latest member in the integrin family, alpha(11)beta(1), recognizes collagens using C2C12 cells transfected with alpha(11) cDNA and the bacterially expressed recombinant a…
News from an Ancient World: Two Novel Astacin Metalloproteases from the Horseshoe Crab
2008
In this work, we report the cloning, heterologous expression, and characterization of two novel astacin proteases from the chelicerate Limulus polyphemus (horseshoe crab), designated as LAST (Limulus astacin) and LAST_MAM (Limulus astacin containing a MAM domain), respectively. The expression pattern showed ubiquitous occurrence of LAST_MAM, while LAST was predominantly restricted to the eyes and brain, indicating a function in the nervous system. Both enzymes contain the characteristic metzincin-type zinc-binding region and Met turn. While LAST is made up only of the typical prodomain and astacin-like protease domain, LAST_MAM contains an additional MAM (meprin A5 protein tyrosine phosphat…
Structural requirements for V2 vasopressin receptor proteolytic cleavage.
1999
The ligand-induced proteolytic cleavage of the V2 vasopressin receptor transiently expressed in COS cells was investigated. After incubation of the cell membranes with a photoreactive ligand possessing full agonistic properties for V2 receptors, approximately 90% of the porcine and bovine V2 vasopressin receptors were cleaved in the upper part of transmembrane helix 2 at a heptapeptide sequence conserved in both vasopressin and oxytocin receptors. The oxytocin receptor was completely resistant to proteolysis after binding the same photoreactive ligand, which is only a partial agonist for this receptor. Chimeric V2/oxytocin receptors obtained by transfer of extracellular domains of the oxyto…
The Sequence of a Gastropod Hemocyanin (HtH1 from Haliotis tuberculata)
2000
The eight functional units (FUs), a-h, of the hemocyanin isoform HtH1 from Haliotis tuberculata (Prosobranchia, Archaeogastropoda) have been sequenced via cDNA, which provides the first complete primary structure of a gastropod hemocyanin subunit. With 3404 amino acids (392 kDa) it is the largest polypeptide sequence ever obtained for a respiratory protein. The cDNA comprises 10,758 base pairs and includes the coding regions for a short signal peptide, the eight different functional units, a 3'-untranslated region of 478 base pairs, and a poly(A) tail. The predicted protein contains 13 potential sites for N-linked carbohydrates (one for HtH1-a, none for HtH1-c, and two each for the other si…
cDNA Cloning and Functional Expression of Jerdostatin, a Novel RTS-disintegrin from Trimeresurus jerdonii and a Specific Antagonist of the α1β1 Integ…
2005
Jerdostatin represents a novel RTS-containing short disintegrin cloned by reverse transcriptase-PCR from the venom gland mRNA of the Chinese Jerdons pit viper Trimeresurus jerdonii. The jerdostatins precursor cDNA contained a 333-bp open reading frame encoding a signal peptide, a pre-peptide, and a 43-amino acid disintegrin domain, whose amino acid sequence displayed 80% identity with that of the KTS-disintegrins obtustatin and viperistatin. The jerdostatin cDNA structure represents the first complete open reading frame of a short disintegrin and points to the emergence of jerdostatin from a short-coding gene. The different residues between jerdostatin and obtustatin/viperistatin are segreg…
Subunit organization of the abalone Haliotis tuberculata hemocyanin type 2 (HtH2), and the cDNA sequence encoding its functional units d, e, f, g and…
1999
We have developed a HPLC procedure to isolate the two different hemocyanin types (HtH1 and HtH2) of the European abalone Haliotis tuberculata. On the basis of limited proteolytic cleavage, two-dimensional immunoelectrophoresis, PAGE, N-terminal protein sequencing and cDNA sequencing, we have identified eight different 40-60-kDa functional units (FUs) in HtH2, termed HtH2-a to HtH2-h, and determined their linear arrangement within the elongated 400-kDa subunit. From a Haliotis cDNA library, we have isolated and sequenced a cDNA clone which encodes the five C-terminal FUs d, e, f, g and h of HtH2. As shown by multiple sequence alignments, defg of HtH2 correspond structurally to defg from Octo…
Functional characterization of human nucleosome assembly protein-2 (NAP1L4) suggests a role as a histone chaperone.
1997
Abstract Histones are thought to play a key role in regulating gene expression at the level of DNA packaging. Recent evidence suggests that transcriptional activation requires competition of transcription factors with histones for binding to regulatory regions and that there may be several mechanisms by which this is achieved. We have characterized a human nucleosome assembly protein, NAP-2, previously identified by positional cloning at 11p15.5, a region implicated in several disease processes including Wilms tumor (WT) etiology. The deduced amino acid sequence of NAP-2 indicates that it encodes a protein with a potential nuclear localization motif and two clusters of highly acidic residue…