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1.
Graciela E. Santillán Marisa J. Sandoval Yuti Chernajovsky Patricia L. Orchansky 《Molecular and cellular biochemistry》1992,110(2):181-191
A number of cell-surface proteins are anchored in plasma membranes by a glycosylated phosphatidylinositol (PI) moiety that
is covalently attached to the carboxyl-terminal amino acid of the mature protein. We have previously reported the construction
of a cDNA clone of a truncated Platelet-derived growth factor (PDGF) receptor that consists of the extracellular domain without
the transmembrane and cytoplasmic domains. In the construction of the vector, a sequence of 51 base pairs (bp) from the 3′-untranslated
region of the receptor cDNA was linked in frame with the external domain coding sequence. The truncated receptor protein with
the peptide VTSGHCHEERVDRHDGE fused to its carboxyl terminus was covalently attached to the membrane by a PI linkage and it
was released by phosphatidylinositol specific-phospholipase C (PI-PLC). When the 51 bp sequence was deleted, the external
domain receptor protein was secreted into the media. To determine whether the PI linkage of the protein was due to the 17
amino acids added, the peptide was fused to the carboxyl terminus of the secreted protein human Interferon-β (hu-IFN-β). Chinese
hamster ovary (CHO) cells transfected with the hu-IFN-β cDNA secreted the protein to theconditioned media, whereas CHO cells
transfected with the carboxyl terminus modified-hu-IFN-β cDNA did not secrete detectable levels of protein. CHO cells expressing
the carboxyl terminus modified-hu-IFN-β were treated with PI-PLC, the media and cell lysates were analyzed by SDS-PAGE after
immunoprecipitation with antibodies against hu-IFN-β. The modified protein is anchored to the plasma membrane by a PI linkage
and it is specifically released by PI-PLC, whereas a control preparation of CHO cells expressing wild type hu-IFN-β does not
show the same pattern. The 17 amino acid peptide fused to the carboxyl terminus of IFN-β directs attachment of a PI anchor
and targets the fusion protein to the plasma membrane. 相似文献
2.
The production of a proteinase from Lactobacillus helveticus CRL 581 was studied. The highest specific activity was found at the early exponential growth phase of cells cultured in milk.
The lowest levels of proteinase were detected in MRS broth, while in the casein–yeast extract–glucose broth enzyme production
increased gradually during the fermentation and reached maximal values at the stationary phase. The proteinase, found to be
associated with the cell membrane fraction, hydrolyzed β-casein more rapidly than α-casein. The enzyme was not released from
washed cells in the presence or absence of calcium, which suggests that the enzyme did not undergo self-digestion.
Received: 28 January 1997 / Accepted: 8 March 1997 相似文献
3.
4.
Hanieh Bagheri Tudashki Youssef Haddad Iness Charfi Rejean Couture Graciela Pineyro 《Journal of cellular and molecular medicine》2020,24(10):5718-5730
δ-opioid receptor (DOPr) agonists have analgesic efficacy in chronic pain models but development of tolerance limits their use for long-term pain management. Although agonist potential for inducing acute analgesic tolerance has been associated with distinct patterns of DOPr internalization, the association between trafficking and chronic tolerance remains ill-defined. In a rat model of streptozotocin (STZ)-induced diabetic neuropathy, deltorphin II and TIPP produced sustained analgesia following daily (intrathecal) i.t. injections over six days, whereas similar treatment with SNC-80 or SB235863 led to progressive tolerance and loss of the analgesic response. Trafficking assays in murine neuron cultures showed no association between the magnitude of ligand-induced sequestration and development of chronic tolerance. Instead, ligands that supported DOPr recycling were also the ones producing sustained analgesia over 6-day treatment. Moreover, endosomal endothelin-converting enzyme 2 (ECE2) blocker 663444 prevented DOPr recycling by deltorphin II and TIPP and precipitated tolerance by these ligands. In conclusion, agonists, which support DOPr recycling, avoid development of analgesic tolerance over repeated administration. 相似文献
5.
Graciela De Lara-Isassi Sergio Álvarez-Hernández Ligia Collado-Vides 《Journal of applied phycology》2000,12(1):45-52
Seventy-three species of macroalgae from the Mexican Pacific, Atlantic and Caribbean coast were screened for ichtyotoxic activity.
Ethanolic, acetonic and aqueous extracts were prepared and tested against the fish Carassius auratus. The extracts were classified on the basis of their effects as: toxic if the fish died in two hours or less; moderately toxic,
if the organism behaved abnormally but death did notoccur, and non-toxic if the fish did not display any change. 79% species
were ichtyotoxic to some degree. Extracts of 39 species were toxic, with at least one extract with lethal effects, 19 were
moderately toxic and 15 species were non-toxic. Only the extracts ofDictyota bartayresiana, Dictyota cervicornis,Lobophora variegata, Bryothamnion triquetrum and Laurencia obtusa were toxic in all three solvents. The acetone and ethanol extracts were more active, and therefore are more suitable for
extraction of toxic substances.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
6.
7.
M. Graciela Pucciarelli S. Ruschkowski T.J. Trust B.B. Finlay 《FEMS microbiology letters》1995,129(2-3):293-399
Abstract Helicobacter pylori is a bacterial pathogen of humans that infects the gastric mucosa. This infection has been associated with gastritis, peptic ulcers, and gastric carcinomas. Diverse in vitro studies have described efficient adherence of H. pylori to different types of epithelial cells. Because of its varied effects on host cells, we have analysed signal transduction events in H. pyfori -infected epithelial cells. Our results show that H. pylori induces an increase in inositol phosphates in all cultured epithelial cells used, including HeLa, Henle 407, Hep-2, and the human gastric adenocarcinoma cell line AGS. Bacterial growth medium supernatants induce a similar response in the host cell. The increase in inositol phosphates is not related to redistribution of cytoskeletal proteins such as actin or α-actinin nor tyrosine-phosphorylation of host cell proteins. The inositol phosphate increase is also observed in cells infected with low or non-adherent H. pylori mutants or mutants defective in the vacuolating toxin or urease holoenzyme. These results indicate that inositol phosphate release in H. pytori -infected cells is not dependent on bacterial adherence, and that a soluble bacterial factor, but not the vacuolating toxin or urease holoenzyme, mediates such an effect. 相似文献
8.
Héctor Palafox-Fonseca Gerardo Zú?iga Raúl José Bobes Tzipe Govezensky Daniel Pi?ero Laura Texco-Martínez Agnès Fleury Jefferson Proa?o Graciela Cárdenas Marisela Hernández Edda Sciutto Gladis Fragoso 《Memórias do Instituto Oswaldo Cruz》2013,108(7):914-920
Neurocysticercosis (NC) is a clinically and radiologically heterogeneous parasitic disease caused by the establishment
of larval Taenia solium in the human central nervous system. Host and/or parasite variations may be related to this observed heterogeneity. Genetic differences between pig and human-derived T. solium cysticerci have been reported previously. In this study, 28 cysticerci were surgically removed from 12 human NC patients, the mitochondrial gene that encodes cytochrome b was amplified from the cysticerci and genetic variations that may be related to NC heterogeneity were characterised. Nine different haplotypes (Ht), which were clustered in four haplogroups (Hg), were identified. Hg 3 and 4 exhibited a tendency to associate with age and gender, respectively. However, no significant associations were found between NC heterogeneity and the different T. solium cysticerci Ht or Hg. Parasite variants obtained from patients with similar NC clinical or radiological features were genetically closer than those found in groups of patients with a different NC profile when using the Mantel test. Overall, this study establishes the presence of genetic differences in the Cytb gene of T. solium isolated from human cysticerci and suggests that parasite variation could contribute to NC heterogeneity. 相似文献
9.
10.
The brood cycle in anostracans results from the overlapping of two successive reproductive cycles in the genital tract of females. While a clutch of oocytes begins to mature at the ovaries (ovarian period), the nauplii, cysts or unfertilised products of a previous clutch are developing in the ovisac or being released to the medium (oviduct-ovisac period). Models are proposed for the sequence of stages and their duration in a complete brood cycle under two treatments, i.e., females with males (1:1 ratio), and isolated virginal females of Artemia persimilis in laboratory conditions. The whole brood cycle in both treatments took 6 days, however, they differed in the duration of some stages. The differences are discussed and observations on amplexus are added. 相似文献