Looking for online definition of ras-related GTP-binding protein 4b in the Medical Dictionary? ras-related GTP-binding protein 4b explanation free. What is ras-related GTP-binding protein 4b? Meaning of ras-related GTP-binding protein 4b medical term. What does ras-related GTP-binding protein 4b mean?
Looking for online definition of guanine nucleotide binding protein (G protein), beta polypeptide 4 in the Medical Dictionary? guanine nucleotide binding protein (G protein), beta polypeptide 4 explanation free. What is guanine nucleotide binding protein (G protein), beta polypeptide 4? Meaning of guanine nucleotide binding protein (G protein), beta polypeptide 4 medical term. What does guanine nucleotide binding protein (G protein), beta polypeptide 4 mean?
BioAssay record AID 448131 submitted by ChEMBL: Agonist activity at human CB2 receptor expressed in CHO cells by [35S]GTPgammaS binding assay.
Looking for online definition of GTP-binding protein RAB10 in the Medical Dictionary? GTP-binding protein RAB10 explanation free. What is GTP-binding protein RAB10? Meaning of GTP-binding protein RAB10 medical term. What does GTP-binding protein RAB10 mean?
8-hydroxyguanosine (8-OHG) is a marker for measuring the rate of oxidative damage to nucleic acids and lipids. Production of reactive oxygen species (ROS) damage proteins, lipid membranes, and nucleic acids (DNA and RNA), all critical functional components of living cells. The progressive accumulation of unrepaired free radical damage over time is believed to be a major contributor to the aging process and to a variety of age-related chronic diseases. Generation of most free radicals is a side effect of normal metabolic processes, especially mitochondrial production of ROS, including superoxide anion, hydrogen peroxide, and hydroxyl radical, coincident to oxidative metabolism. (PMID 14607529 ). 8-OHG (marker of oxidative damage to RNA) was found in the cerebral cortex in three of six cases of neuropathologically examined autopsy of subacute sclerosing panencephalitis patients. Subacute sclerosing panencephalitis is caused by persistent brain infection of mutated measles virus, showing ...
Author: Praefcke, G. J. K. et al.; Genre: Other; Published in Print: 2000; Title: Identification of regions in human guanylate binding protein 1 (hGBP1) responsible for oligomerization and GTPase activity
Permeabilization of amoebae of Dictyostelium discoideum with saponin was found not to uncouple the chemotactic cell surface cyclic AMP receptors from inositol trisphosphate (IP3) formation, and stimulation of permeabilized amoebae with 50 nM-cyclic AMP produced peaks of IP3 at 5, 15 and 30 s in a manner comparable to that seen previously in non-permeabilized cells. The possible involvement of a GTP-binding protein (G-protein) in this IP3 signal transduction pathway was investigated by studying the effects on such permeabilized amoebae of added GTP and non-hydrolysable GTP analogues. While GDP produced only very minor effects, stimulation of the amoebae (in the absence of added cyclic AMP) with GTP or the non-hydrolysable GTP analogues GTP gamma S (guanosine 5′-O-(3-thio-triphosphate] and Gpp(NH)p (5′-guanylylimidodiphosphate) induced transient formation of IP3 in an oscillatory manner, with peaks similar in magnitude and timing to those elicited by cyclic AMP. A dose-response curve for GTP ...
Looking for online definition of guanine nucleotide-binding protein G(I)/G(S)/G(T) beta subunit 1 in the Medical Dictionary? guanine nucleotide-binding protein G(I)/G(S)/G(T) beta subunit 1 explanation free. What is guanine nucleotide-binding protein G(I)/G(S)/G(T) beta subunit 1? Meaning of guanine nucleotide-binding protein G(I)/G(S)/G(T) beta subunit 1 medical term. What does guanine nucleotide-binding protein G(I)/G(S)/G(T) beta subunit 1 mean?
Novel compounds that mimic and/or modulate the activity of wild-type nucleic acids. In general, the compounds are phosphorothioate oligonucleotides wherein the 5′-terminal internucleoside linkage or the 5′- and 3′-terminal linkages are modified.
NOTOC__ {{Infobox_Disease , Name = Purine nucleoside phosphorylase deficiency , Image = , Caption = , DiseasesDB = 11044 , ICD10 = {{ICD10,D,81,5,d,80}} , ICD9 = {{ICD9,277.2}} , ICDO = , OMIM = 164050 , MedlinePlus = , MeshID = , }} {{SI}} {{CMG}} {{SK}} PNP-deficiency ==Overview== Purine nucleoside phosphorylase deficiency, often called PNP-deficiency, is a rare congenital [[immunodeficiency]] of [[purine nucleoside phosphorylase]]. This enzyme is important in the purine degradation pathway. A deficiency of it causes [[T-cell]] immunodeficiency. It is also often associated with neurological disorders such as [[mental retardation]]. This [[autosomal recessive]] [[metabolic disorder]] results in [[severe combined immunodeficiency]]. ==Historical Perspective== ==Classification== ==Pathophysiology== The disorder is caused by a disruption of the [[purine nucleoside phosphorylase]], a key enzyme in the purine salvage pathway. This enzyme is required for [[purine]] degradation. ...
Members of the Rho (or ARH) protein family (see MIM 165390) and other Ras-related small GTP-binding proteins (see MIM 179520) are involved in diverse cellular events, including cell signaling, proliferation, cytoskeletal organization, and secretion. The GTP-binding proteins are active only in the GTP-bound state. At least 3 classes of proteins tightly regulate cycling between the GTP-bound and GDP-bound states: GTPase-activating proteins (GAPs), guanine nucleotide-releasing factors (GRFs), and GDP-dissociation inhibitors (GDIs). The GDIs, including ARHGDIB, decrease the rate of GDP dissociation from Ras-like GTPases (summary by Scherle et al., 1993 [PubMed 8356058]).[supplied by OMIM, Dec 2010 ...
Members of the Rho family of GTP‐binding proteins function as molecular switches in biological response pathways that result in changes in the actin cytoskeletal architecture, the stimulation of cell cycle progression and gene transcription, and the regulation of intracellular trafficking activities (Van Aelst and DSouza‐Schorey, 1997; Hall, 1998; Bar‐Sagi and Hall, 2000; Erickson and Cerione, 2001). Three classes of proteins, GTPase‐activating proteins (GAPs), guanine nucleotide dissociation inhibitors (GDIs), and guanine nucleotide exchange factors (GEFs), regulate the cycling of these GTP‐binding proteins between their GDP‐bound and GTP‐bound states (Boguski and McCormick, 1993). Rho family proteins, such as Cdc42 and Rac, are activated by a number of upstream stimuli, as mediated by members of the Dbl (diffuse B‐cell lymphoma) family of GEFs (Whitehead et al, 1997; Hoffman and Cerione, 2002). One subgroup of the Dbl family, the Cool/Pix proteins (Cool for cloned‐out of ...
Primer recognition proteins (PRP) are cofactors for DNA polymerase alpha and may have a role in lagging-strand DNA replication. PRP is composed of two subunits, which we have previously identified as the protein-tyrosine kinase substrate annexin II and phosphoglycerate kinase (PGK). In this study, we have examined the physiological involvement of these proteins in DNA synthesis and cell proliferation. When exponentially growing human HeLa cells are exposed to antisense phosphorothioate oligodeoxynucleotides to annexin II, ongoing DNA synthesis is reduced. The extent of reduction with antisense oligodeoxynucleotide to PGK was much less than with the antisense annexin II oligodeoxynucleotide. Reductions in the labeling and mitotic indices of HeLa cell cultures are seen after exposure to antisense oligodeoxynucleotides. Flow cytometric analyses indicate that progression from S phase to G2 phase of the cycle is retarded by exposure of cells to the antisense oligodeoxynucleotides. Corresponding sense ...
The Rac proteins, Rac1 and Rac2, are essential components of the NADPH oxidase system of phagocytes and regulate the actin assembly associated with membrane ruffling. These functions are controlled by the GTP-bound form of Rac. The biochemical interaction between Rac and its only known GDP-dissociation stimulator (termed smgGDS) was characterized. SmgGDS was able to stimulate the incorporation of guanosine 5′-[gamma-thio]-triphosphate GTP[gamma S] into the RhoA, Rac2, Rac1, Rap1A and CDC42Hs GTP-binding proteins, but the activity was greatest toward RhoA and Rac2. Isoprenoid modification of these proteins was not absolutely required for the interaction with smgGDS. Interestingly, the activity of smgGDS toward Rac1 could not be observed in a [3H]GDP/GTP exchange assay under conditions where it stimulated incorporation of GTP[gamma S] into Rac1. We determined that smgGDS prevented the loss of Rac1 activity during the [3H]GDP/GTP exchange assay by demonstrating the ability of smgGDS to inhibit ...
Professor Steven P. Brown from the Department of Physics, with colleagues in the Department of Chemistry, have identified that the supramolecular structure of a guanosine derivative can be different upon passing from the solid state into the solution state and vice versa.. This defies chemical precedent, as self-assembled structures driven by the formation of specific intermolecular hydrogen bonds in solution would be expected to remain the same in the solid state.. The phenomenon was revealed by the state-of-the-art nuclear magnetic resonance (NMR) facility at Warwick.. In solution state, the guanosine derivative analysed by the researchers is constituted by quartet-like molecular structure - and scientific intuition would suggests that this should remain like this in the solid state.. However, upon changing into the solid state, the supramolecular assembly surprisingly contains both quartet and ribbon structures.. Professor Brown and his colleagues made this discovery using advanced NMR ...
As a member of the wwPDB, the RCSB PDB curates and annotates PDB data according to agreed upon standards. The RCSB PDB also provides a variety of tools and resources. Users can perform simple and advanced searches based on annotations relating to sequence, structure and function. These molecules are visualized, downloaded, and analyzed by users who range from students to specialized scientists.
IN all eukaryotic cells, Rab family small GTPases (Rabs) form the largest branch of the small GTPase superfamily (Takai et al. 2001). In mammals, Rabs define a family of almost 70 proteins that play critical roles in the trafficking of vesicles that mediate transport between compartments of the exocytic and endocytic pathways (Pfeffer 2001, 2005). Like Ras, Rabs act as molecular switches, cycling between an active GTP-bound state and an inactive GDP-bound state. Thus, transport vesicles bear Rabs with bound GTP; concomitant with or after membrane fusion, Rabs are converted into their GDP-bound states. In this manner, target membranes acquire vesicle-derived Rabs in their GDP-bound conformations (Pfeffer et al. 1995).. We have previously identified two Rab family small GTPases, Ypt3/Its5 and Ryh1/Its6, in the fission yeast Schizosaccharomyces pombe through a genetic screen using the immunosuppressant drug FK506, a specific inhibitor of calcineurin (Cheng et al. 2002; He et al. 2006). In the same ...
Sequence-specific phosphorothioate oligonucleotides comprising nucleoside units which are joined together by either substantially all Sp or substantially all Rp phosphorothioate intersugar linkages ar
Nuclear envelope assembly is promoted by phosphoinositide- specific phospholipase C with selective recruitment of phosphatidylinositol-enriched membranes Nuclear envelope (NE) formation in a cell-free egg extract proceeds by precursor membrane vesicle binding to chromatin in an ATP-dependent manner, followed by a GTP-induced NE assembly step. The requirement for GTP in the latter step of this process can be mimicked by addition of bacterial PI-PLC [phosphoinositide (PtdIns)-specific phospholipase C]. The NE assembly process is here dissected in relation to the requirement for endogenous phosphoinositide metabolism, employing recombinant eukaryotic PI-PLC, inhibitors and direct phospholipid analysis using ESI-MS (electrospray ionization mass spectrometry). PtdIns (phosphatidylinositol) species analysis by ESI-MS indicates that the chromatin-bound NE precursor vesicles are enriched for specific PtdIns species. Moreover, during GTP-induced precursor vesicle fusion. the membrane vesicles become ...
Brefeldin A-inhibited guanine nucleotide-exchange protein 3 (BIG3) has been identified recently as a novel regulator of estrogen signalling in breast cancer cells. Despite being a potential target for new breast cancer treatment, its amino acid sequence suggests no association with any well-characterized protein family and provides little clues as to its molecular function. In this paper, we predicted the structure, function and interactions of BIG3 using a range of bioinformatic tools. Homology search results showed that BIG3 had distinct features from its paralogues, BIG1 and BIG2, with a unique region between the two shared domains, Sec7 and DUF1981. Although BIG3 contains Sec7 domain, the lack of the conserved motif and the critical glutamate residue suggested no potential guaninyl-exchange factor (GEF) activity. Fold recognition tools predicted BIG3 to adopt an α-helical repeat structure similar to that of the armadillo (ARM) family. Using state-of-the-art methods, we predicted interaction sites
The quantitative determination of pertussis-toxin-sensitive guanine-nucleotide-binding proteins (G-proteins) in cell membranes is still a problem. Pertussis-toxin-catalysed [32P]ADP-ribosylation strongly relies on the substrate quality of the alpha-subunits and is influenced by the concentration of nucleotides, beta gamma-subunits, the physicochemical properties of the membranes influencing the availability of Gi alpha for pertussis toxin, and covalent modification of Gi alpha. Quantification of immunoreactive material on Western blots can be only imprecisely performed by two-dimensional densitometry. In order to generate a method for quantification of pertussis-toxin-sensitive G-proteins in membranes we have developed a fast and sensitive radioimmunoassay. The C-terminal decapeptide of retinal transducin alpha (KENLKDCGLF) was 125I-labelled and used as tracer. Polyclonal antiserum (DS 4) was raised against this peptide. Gi alpha proteins were determined by competition of solubilized membranes ...
L-lysyl-L-threonyl-L phenylalanyl-N-3-carboxypropyl)-glycine amide, acetate salt. 5) Treatment of perinatal asphyxia - Allopurinol sodium. 6) Treatment of Duchenne muscular dystrophy - Exon 52 specific phosphorothioate oligonucleotide. 7) Treatment of Duchenne muscular dystrophy - Exon 55 specific phosphorothioate oligonucleotide. 8) Treatment of malaria - Artesunate. 9) Treatment of chronic lymphocytic leukaemia - 4-(4-{[2-(4-chlorophenyl)-4,4-dimethylcyclohex-1-en-1-yl]methyl}piperazin-1-yl)-N-({3-nitro-4-[(tetrahydro-2H-pyran-4-ylmethyl)amino]phenyl}sulfonyl)-2-(1H-pyrrolo[2,3-b]pyridin-5-yloxy)benzamide. 10) Treatment of very-long-chain-acyl-CoA dehydrogenase deficiency - Triheptanoin. 11) Treatment of long-chain L-3-hydroxyacyl-CoA-dehydrogenase deficiency - Triheptanoin. 12) Treatment of chronic lymphocytic leukaemia - Humanised single chain monoclonal antibody against CD37. 13) Treatment of non-infectious uveitis - Voclosporin. Copyright © 2012-2013, Orphan Druganaut Blog. All rights ...
To evaluate differences between CBRs their coupling to G-alpha-i2-proteins was evaluated by immunoblotting, [3H]CP 55,940 competition and saturation binding assays, [32P]GTPase assays and [35S]GTPgammaS binding assays. The expression levels of CB1R were approximately two-fold higher than those of CB2R as determined by immunoblotting. However, [3H]CP 55,940 saturation binding assays revealed even higher Bmax values for the CB1R and lower Bmax values for the CB2R. Further experiments showed that CB1R possesses G-protein independent agonist binding and that a part of the CB2R protein was not functional. GTPgammaS time course binding studies revealed a much faster activation of the CB1R after ligand binding. Compared to CB2R, CB1R possessed a higher constitutive activity, as assessed in GTPgammaS saturation binding and in GTPase assays in the presence of NaCl. For the agonist CP 55,940, an agonist / inverse agonist switch at CB1R was observed and described for the first time ...
Ras-homologous GTPases constitute a large family of signal transducers that alternate between an activated, GTP-binding state and an inactivated, GDP-binding state. These proteins represent cellular switches that are operated by GTP-exchange factors and factors that stimulate their intrinsic GTPase activity. All GTPases of the Ras superfamily have in common the presence of six conserved motifs involved in GTP/GDP binding, three of which are phosphate-/magnesium-binding sites (PM1-PM3) and three of which are guanine nucleotide-binding sites (G1-G3). Transcript variants encoding distinct isoforms have been identified. [provided by RefSeq, Jul 2008 ...
The effects of Ca2+-calmodulin on adenylate cyclase activity in EGTA-washed, 27000 g particulate fractions of mouse and rat pancreatic islets were studied. Ca2+ (10 microM)-calmodulin (1 microM) stimulated adenylate cyclase activity 53.1 +/- 5.2 (N = 6)% in the particulate fraction of rat islets. Trifluoperazine (50 microM), a specific inhibitor of calmodulin, inhibited the Ca2+-calmodulin activation of the adenylate cyclase activity of this fraction of rat islets. These results confirm previous reports dealing with Ca2+-Calmodulin and rat islet adenylate cyclase [Valverde, Vandermeers. Anjaneyulu & Malaisse (1979) Science 206, 225-227; Sharp, Wiedenkeller, Kaelin, Siegel & Wollheim (1980) Diabetes 29, 74-77]. In contrast, however, Ca2+ (1-100 microM)-calmodulin (1-10 microM) did not stimulate the adenylate cyclase activity in the EGTA-washed particulate fraction of mouse islets, and trifluoperazine (50 microM) did not inhibit the adenylate cyclase activity of this fraction of mouse islets, ...
PURPOSE: To examine the signal transduction pathways involved in the activation of orbital fibroblast effector functions relevant to the pathogenesis of Graves ophthalmopathy (GO). To determine, using antisense technology, whether the c-myc protooncogene is involved in cell proliferation and glycosaminoglycan (GAG) synthesis in cultured orbital fibroblasts (OF). METHODS: The effects of a 16-mer c-myc antisense phosphorothioate oligodeoxynucleotide (S-ODN) on OF monolayers derived from orbital connective tissue of patients with severe GO (n = 6) and healthy individuals (n = 3) were investigated. Quiescent OF monolayers were treated with serum or cytokines and were exposed to increasing concentrations of a c-myc antisense S-ODN and several control S-ODN. Cell proliferation was quantitated by direct cell counting and by immunocytochemistry for the nuclear Ki-67 antigen. Glycosaminoglycan synthesis was examined by [3H] GAG analysis. The effects of the c-myc antisense S-ODN and control S-ODN on ...
Two genetic defects of the purine salvage pathway account for two immunodeficiencies that result in severe combined immunodeficiency (SCID). One disorder is adenosine deaminase (ADA) deficiency, which is Online Mendelian Inheritance in Man (OMIM) subject number 102700, and the other is purine nucleoside phosphorylase (PNP) deficiency, which i...
Effects of substance P on cultured neurons of the locus coeruleus of the rat were studied using the whole-cell patch clamp technique. In some cells substance P produced a decrease in a K conductance which showed an inwardly rectifying property. In other cells substance P produced an initial inward current which was accompanied by a conductance increase. The rest of the cells showed responses which were mixtures of the above two responses. The measurement of the reversal potential of the initial inward current after suppressing the voltage-gated Ca and K conductances suggests that it is caused by an increase in a non-selective ionic conductance. In cells loaded with 260 microM GTP gamma S, application of substance P produced an irreversible reduction of the K conductance, while the initial inward current could still be recorded, suggesting that the former is mediated by a G protein, whereas the latter may be activated by a different signal transduction mechanism. The initial inward current was not
Muscarinic acetylcholine receptors (mAChR) have critical roles in the central nervous system and produce many of their effects by activating heterotrimeric guanine nucleotide-binding proteins. However, the five subtypes of muscarinic receptors (M1 through M5) produce distinct signals and thus may use other signaling mechanisms as well. McClatchy et al. screened for proteins that interact with the third intracellular loop portion of the M4 mAChR, a region that is highly variable between receptor subtypes. They identified elongation factor 1A2 (eEF1A2) as an interaction partner and showed that endogenous eEF1A2 could be coimmunoprecipitated with the M4 mAChR, but not the M1 mAChR, from cultured PC12 cells. The i3 loop acts as a guanine nucleotide exchange factor for receptor-coupled G proteins and the M4i3 loop also promoted nucleotide exchange on eEF1A2 in vitro. The eEF1A2 protein functions in control of translation and has other proposed functions as well. These functions are thus potentially ...
TY - JOUR. T1 - Signal transduction by guanine nucleotide binding proteins. AU - Spiegel, Allen M.. PY - 1987/1. Y1 - 1987/1. N2 - High affinity binding of guanine nucleotides and the ability to hydrolyze bound GTP to GDP are characteristics of an extended family of intracellular proteins. Subsets of this family include cytosolic initiation and elongation factors involved in protein synthesis, and cytoskeletal proteins such as tubulin (Hughes S.M. (1981) FEBS Lett. 164, 1-8). A distinct subset of guanine nucleotide binding proteins is membrane-associated; members of this subset include the ras gene products (Ellis R.W. et al. (1981) Nature 292, 506-511) and the heterotrimeric G-proteins (also termed N-proteins) (Gilman A.G. (1984) Cell 36, 577-579). Substantial evidence indicates that G-proteins act as signal transducers by coupling receptors (R) to effectors (E). A similar function has been suggested but not proven for the ras gene products. Known G-proteins include Gs and Gi, the G-proteins ...
Our observations that BCE suppressed not only radiation-induced MN and gene mutations but also radiation-induced intracellular ROS indicate that BCE has radioprotective activity.. Radiation induces DSBs in DNA, which result in chromosomal aberrations and cell death, generating a wide variety of ROS that induce gene mutations following the occurrence of oxidative bases in DNA [10]. The production of DSBs in DNA activates DNA damage checkpoint signaling and DNA repair pathways, which employ nonhomologous end joining (NHEJ) and homologous recombination (HR) [11]. In contrast, ionizing radiation induces ROS including superoxide anions, hydrogen peroxide, and hydroxyl radicals [12]. These ROS damage several kinds of biomolecules including DNA, proteins, and lipids [13]. ROS is scavenged by superoxide dismutase and catalase [13, 14]. Oxidative nucleotides such as 8-hydroxyguanosine (8-oxodG, 8OHdG, and 8OHG) are mutagenic lesions that are formed by ROS in the nucleotide pool as well as in DNA ...
The Escherichia coli guanosine triphosphate (GTP)-binding proteins Ffh and FtsY have been proposed to catalyze the cotranslational targeting of proteins to the bacterial plasma membrane. A mutation was introduced into the GTP-binding domain of FtsY that altered its nucleotide specificity from GTP to xanthosine triphosphate (XTP). The mutant FtsY protein stimulated GTP hydrolysis by a ribonucleoprotein consisting of Ffh and 4.5S RNA in a reaction that required XTP, and it hydrolyzed XTP in a reaction that required both the Ffh-4.5S ribonucleoprotein and GTP. Thus, nucleotide triphosphate hydrolysis by Ffh and FtsY is likely to occur in reciprocally coupled reactions in which the two interacting guanosine triphosphatases act as regulatory proteins for each other. ...
TY - JOUR. T1 - Identification and characterization of a new family of guanine nucleotide exchange factors for the Ras-related GTPase Ral. AU - Rebhun, John F.. AU - Chen, Hongsheng. AU - Quilliam, Lawrence A.. PY - 2000/5/5. Y1 - 2000/5/5. N2 - Guanine nucleotide exchange factors (GEFs) are responsible for coupling cell surface receptors to Ras protein activation. Here we describe the characterization of a novel family of differentially expressed GEFs, identified by database sequence homology searching. These molecules share the core catalytic domain of other Ras family GEFs but lack the catalytic non- conserved (conserved non-catalytic/Ras exchange motif/structurally conserved region 0) domain that is believed to contribute to Sos1 integrity. In vitro binding and in vivo nucleotide exchange assays indicate that these GEFs specifically catalyze the GTP loading of the Ral GTPase when overexpressed in 293T cells. A central proline-rich motif associated with the Src homology (SH)2/SH3-containing ...
China Excellent Quality Trimethyl Thiophosphate CAS 152-18-1, Find details about China Trimethyl Thiophosphate, Trimethyl Thiophosphate Supplier from Excellent Quality Trimethyl Thiophosphate CAS 152-18-1 - Dalian Chem Imp.& Exp. Group Co., Ltd.
CXC chemokine receptors are integral membrane proteins that specifically bind and respond to cytokines of the CXC chemokine family. They represent one subfamily of chemokine receptors, a large family of G protein-linked receptors that are known as seven transmembrane (7-TM) proteins, since they span the cell membrane seven times. There are currently seven known CXC chemokine receptors in mammals, named CXCR1 through CXCR7. CXCR1 and CXCR2 are closely related receptors that recognize CXC chemokines that possess an E-L-R amino acid motif immediately adjacent to their CXC motif. CXCL8 (otherwise known as interleukin-8) and CXCL6 can both bind CXCR1 in humans, while all other ELR-positive chemokines, such as CXCL1 to CXCL7 bind only CXCR2. They are both expressed on the surface of neutrophils in mammals. CXCR3 is expressed predominantly on T cells (T lymphocytes), and also on other lymphocytes [some B cells (B lymphocytes) and NK cells] and is highly induced following cell activation. There are two ...
Guanine nucleotide exchange factor for Arf GTPases, stimulating the nucleotide exchange from the GDP-bound to the GTP-bound form. Catalyzes both the GDP release by and the GTP binding to ARF2. Has no exhange activity on Rab GTPases. Involved in vesicular transport.
Guanine is one of the five main nucleobases found in the nucleic acids DNA and RNA. Guanine is a derivative of purine, consisting of a fused pyrimidine-imidazole ring system with conjugated double bonds. Being unsaturated, the bicyclic molecule is planar. The guanine nucleoside is called guanosine. The first isolation of guanine was reported in 1844 from the excreta of sea birds, known as guano, which was used as a source of fertilizer. High affinity binding of guanine nucleotides and the ability to hydrolyze bound GTP to GDP are characteristics of an extended family of intracellular proteins. Guanine nucleotide-binding regulatory proteins may be involved in the activation of phospholipases C and A2 by hormones and other ligands. The binding of hormones to receptors that activate phospholipase C is decreased by guanine nucleotides and these hormones also stimulate a high-affinity GTPase activity in cell membranes. Effects of hormones on phospholipase C activity in cell-free preparations are ...
Guanyl nucleotide binding-proteins, or G-proteins, are ubiquitous molecules that are involved in cellular signal transduction mechanisms. Because a role has been established for cAMP in meiosis and G-proteins participate in cAMP-generating systems by stimulating or inhibiting adenylate cyclase, the present study was conducted to examine the possible involvement of G-proteins in the resumption of meiotic maturation. Cumulus cell-free mouse oocytes (denuded oocytes) were maintained in meiotic arrest in a transient and dose-dependent manner when microinjected with the nonhydrolyzable GTP analog, GTP gamma S. This effect was specific for GTP gamma S, because GppNHp, GTP, and ATP gamma S were without effect. Three compounds, known to interact with G-proteins, were tested for their ability to modulate meiotic maturation: pertussis toxin, cholera toxin, and aluminum fluoride (AlF4-). Pertussis toxin had little effect on maturation in either cumulus cell-enclosed oocytes or denuded oocytes when
Schuermann A., Brauers A., Massmann S., Becker W., Joost H.-G.. cDNA clones of two novel Ras-related GTP-binding proteins (RagA and RagB) were isolated from rat and human cDNA libraries. Their deduced amino acid sequences comprise four of the six known conserved GTP-binding motifs (PM1, -2, -3, G1), the remaining two (G2, G3) being strikingly different from those of the Ras family, and an unusually large C-terminal domain (100 amino acids) presumably unrelated to GTP binding. RagA and RagB differ by seven conservative amino acid substitutions (98% identity), and by 33 additional residues at the N terminus of RagB. In addition, two isoforms of RagB (RagBs and RagB1) were found that differed only by an insertion of 28 codons between the GTP-binding motifs PM2 and PM3, apparently generated by alternative mRNA splicing. Polymerase chain reaction amplification with specific primers indicated that both long and short form of RagB transcripts were present in adrenal gland, thymus, spleen, and kidney, ...
Semantic Scholar extracted view of Spermine inhibition of basal and stimulated adenylate cyclase is mediated by the inhibitory GTP-binding protein (Gi). by Carlo Clô et al.
ABBREVIATIONS: H3R, histamine H3 receptor; CNS, central nervous system; h, human; [35S]GTPγS, guanosine-5′-O-(3-[35S]thio) triphosphate; IL3, intracellular loop 3; GPCR, G-protein-coupled receptor; [3H]A-349821, {4′-[3-((2R, 5R)-2,5-dimethyl-pyrrolidin-1-yl)-propoxy]-biphenyl-4-yl}-morpholin-4-yl-methanone; RT, reverse transcriptase; PCR, polymerase chain reaction; DMEM, Dulbeccos modified Eagles medium; PKA, protein kinase A; PBS, phosphate-buffered saline; CTC, cubic ternary complex; NαMH, Nα-[methyl-3H]histamine; IPP, [125I]iodophenpropit; FUB322, 3-(1H-imidazol-4-yl) propyl-di(p-fluorophenyl)-methyl ether hydrochloride; A-304121, (R)-2-amino-1-{4-[3-(4-cyclopropanecarbonyl-phenoxy)-propyl]-piperazin-1-yl}-propan-1-one; A-317920, furan-2-carboxylic acid, ((R)-2-{4-[3-(4-cyclopropanecarbonyl-phenoxy)-propyl]-piperazin-1-yl}-1-methyl-2-oxo-ethyl)-amide; A-320436, furan-2-carboxylic acid, ...
We investigated how the type III secretion system WxxxE effectors EspM2 of enterohaemorrhagic Escherichia coli, which triggers stress fibre formation, and SifA of Salmonella enterica serovar Typhimurium, which is involved in intracellular survival, modulate Rho GTPases. We identified a direct interaction between EspM2 or SifA and nucleotide-free RhoA. Nuclear Magnetic Resonance Spectroscopy revealed that EspM2 has a similar fold to SifA and the guanine nucleotide exchange factor (GEF) effector SopE. EspM2 induced nucleotide exchange in RhoA but not in Rac1 or H-Ras, while SifA induced nucleotide exchange in none of them. Mutating W70 of the WxxxE motif or L118 and I127 residues, which surround the catalytic loop, affected the stability of EspM2. Substitution of Q124, located within the catalytic loop of EspM2, with alanine, greatly attenuated the RhoA GEF activity in vitro and the ability of EspM2 to induce stress fibres upon ectopic expression. These results suggest that binding of SifA to RhoA ...
Inosine, guanosine and adenosine strongly stimulated proinsulin biosynthesis and insulin secretion in isolated mouse pancreatic islets. None of the purine ribonucleosides stimulated insulin secretion in rat islets, although as reported [jain & Logothetopoulos (1977) Endocrinilogy 100, 923-927] inosine and guanosine, but no adenosine, were potent stimulants of proinsulin biosynthesis in this species. The purine bases had no effect in either species. D-Ribose, which enhanced proinsulin biosynthesis at 0.3 and 0.6 mM but not at 5mM in rat pancreatic islets [jain & Logothetopoulos (1977) Endocrinology 100, 923-927], produced no secretory signals in rat islets and was without any effect on proinsulin biosynthesis and insulin secretion in mouse islets. The rates of oxidation of 14C-labelled purine ribonucleosides and D-ribose in islets of the two species correlated well with their effectiveness as inducers of insulin secretion and proinsulin biosynthesis. Specific inhibitors of purine ribonucleoside ...
Buy 8-CPT-cAMP (CAS 93882-12-3), a water soluble cAMP analog. Join researchers using high quality 8-CPT-cAMP from Abcam and achieve your mission, faster.
Large complex RNAs, like the Tetrahymena ribozyme, tend to have complex kinetic folding pathways with multiple intermediates. Are these intermediates required for folding, or are they the result of kinetic traps? One way to discriminate between these possibilities is to vary folding conditions such as temperature or ion concentration or to make mutations that may destabilize the folding intermediates and to see how these changes affect folding rates. In the present study, the effects of [Mg2+] and temperature on the rates of P3-P7 formation (kP3-P7) and folding to the catalytically active structure (koverall) were compared for the wild-type Tetrahymena ribozyme and the A183U mutant ribozyme. Reducing the [Mg2+] leads to an increase in the value of koverall and reveals the presence of an additional kinetic trap on the folding pathway of both ribozymes. Interestingly, this trap is stabilized by high [Mg2+]. Recent studies with the self-splicing Tetrahymena group I intron pre-RNA, from which the ...
TY - JOUR. T1 - Efficient delivery of an antisense oligodeoxyribonucleotide formulated in folate receptor-targeted liposomes. AU - Chiu, Shih Jiuan. AU - Marcucci, Guido. AU - Lee, Robert J.. PY - 2006/3. Y1 - 2006/3. N2 - Background: Folate receptors (FRs) are cellular surface markers for numerous solid tumors and myeloid leukemias. The aim of this study was to develop an antisense oligodeoxyribonucleotide (ODN) carrier targeting FR-overexpressing cancer cells using folate (FA) as the targeting moiety. G3139, a phosphorothioate antisense ODN against human bcl2 mRNA, was evaluated in this study. Materials and Methods: G3139-containing liposomes were prepared using an ethanol dilution method. For the targeted formulation, 0.5 mol% of folate-PEG-DSPE was incorporated as a targeting ligand into cationic liposomes composed of DC-Chol/egg PC/PEG-DSPE at 25:65:10 mol/mol. Particle size and surface charge were measured and cellular uptake was assessed by fluorescence microscopy and flow cytometry. The ...
The G protein-coupled receptor (GPCR) rhodopsin is found in rod outer segment membranes in the retina and is composed of the apoprotein opsin covalently bound to the ligand 11-cis retinal. Exposure to light converts the ligand to all-trans retinal, which activates the receptor. Rhodopsin then couples to the G protein transducin (Gt), inducing GDP-GTP exchange at the G protein α-subunit (Gαt), which then dissociates from the Gβγ dimer to initiate downstream signaling. Gao et al. isolated rhodopsin from bovine rod outer segment membranes and mixed it with Gβ1γ1 and an engineered α-subunit, eGαt, in the presence or absence of the nanobody Nb35*, which binds to G proteins to help with structure determination. These complexes were capable of undergoing nucleotide exchange and G protein activation. The authors then used single-particle cryo-EM to solve the structures of the Nb35*-bound and Nb35*-free complexes. These structures revealed the extent of the interface between the receptor and the ...
RNA cap guanine-N2 methyltransferases such as Schizosaccharomyces pombe Tgs1 and Giardia lamblia Tgs2 catalyze methylation of the exocyclic N2 amine of 7-methylguanosine. Here we performed a mutational analysis of Giardia Tgs2, entailing an alanine scan of 17 residues within the minimal active domain. Alanine substitutions at Phe18, Thr40, Asp76, Asn103 and Asp140 reduced methyltransferase specific activity to ,3% of wild-type Tgs2, thereby defining these residues as essential. Alanines at Pro142, Tyr148 and Pro185 reduced activity to 7-12% of wild-type. Structure-activity relationships at Phe18, Thr40, Asp76, Asn103, Asp140 and Tyr148, and at three other essential residues defined previously (Asp68, Glu91 and Trp143) were gleaned by testing the effects of 18 conservative substitutions. Our results engender a provisional map of the Tgs2 active site, which we discuss in light of crystal structures of related methyltransferases. A genetic analysis of S. pombe Tgs1 showed that it is nonessential. ...
Ahnert-Hilger, G.; Wegenhorst, U.; Stecher, B.; Spicher, K.; Rosenthal, W.; Gratzl, Manfred (1992): Exocytosis from permeabilized bovine adrenal chromaffin cells is differently modulated by guanosine 5-[gamma-thio]triphosphate and guanosine 5-[beta gamma-imido]triphosphate. Evidence for the involvement of various guanine nucleotide-binding proteins. In: Biochemical Journal, Vol. 284: pp. 321-326 [PDF, 3MB] ...
Downloadable! We analyse the Granger causal relationships between foreign direct investment (FDI) and GDP in a sample of 31 developing countries covering 31 years. Using estimators for heterogeneous panel data we find bi-directional causality between the FDI-to-GDP ratio and the level of GDP. FDI has a lasting impact on GDP, while GDP has no long-run impact on the FDI-to-GDP ratio. In that sense FDI causes growth. Furthermore, in a model for GDP and FDI as a fraction of gross capital formation (GCF) we also find long-run effects from FDI to GDP. This finding may be interpreted as evidence in favour of the hypotheses that FDI has an impact on GDP via knowledge transfers and adoption of new technology. Copyright United Nations University 2006.

(This abstract was borrowed from another version of this item.)