Search results for "membrane proteins"
showing 10 items of 713 documents
Pharmacological blockade of the fatty acid amide hydrolase (FAAH) alters neural proliferation, apoptosis and gliosis in the rat hippocampus, hypothal…
2015
Endocannabinoids participate in the control of neurogenesis, neural cell death and gliosis. The pharmacological effect of the fatty acid amide hydrolase (FAAH) inhibitor URB597, which limits the endocannabinoid degradation, was investigated in the present study. Cell proliferation (phospho-H3(+) or BrdU(+) cells) of the main adult neurogenic zones as well as apoptosis (cleaved caspase-3(+)), astroglia (GFAP(+)), and microglia (Iba1(+) cells) were analyzed in the hippocampus, hypothalamus and striatum of rats intraperitoneally treated with URB597 (0.3 mg/kg/day) at one dose/4-days resting or 5 doses (1 dose/day). Repeated URB597 treatment increased the plasma levels of the N-acylethanolamine…
Clostridium difficile Toxins Disrupt Epithelial Barrier Function by Altering Membrane Microdomain Localization of Tight Junction Proteins
2001
ABSTRACT The anaerobic bacterium Clostridium difficile is the etiologic agent of pseudomembranous colitis. C. difficile toxins TcdA and TcdB are UDP-glucosyltransferases that monoglucosylate and thereby inactivate the Rho family of GTPases (W. P. Ciesla, Jr., and D. A. Bobak, J. Biol. Chem. 273:16021–16026, 1998). We utilized purified reference toxins of C. difficile , TcdA-10463 (TcdA) and TcdB-10463 (TcdB), and a model intestinal epithelial cell line to characterize their influence on tight-junction (TJ) organization and hence to analyze the mechanisms by which they contribute to the enhanced paracellular permeability and disease pathophysiology of pseudomembranous colitis. The increase i…
Presence of a capsule in Vibrio vulnificus biotype 2 and its relationship to virulence for eels
1993
Strains of Vibrio vulnificus biotype 2, isolated from internal organs of diseased European eels as pure cultures of opaque cells, together with some reference strains from Japanese eels, were used in this study. Spontaneous translucent-phase variants were obtained from the corresponding parent strains and compared for a variety of phenotypic traits related to virulence for eels. The rate of colony dissociation from opaque to translucent cells was higher (around 10(-2)) than that observed for translucent to opaque cells (10(-3) to 10(-4)). Electron microscopy with ruthenium red revealed the presence of a capsule of variable thickness on opaque cells, whereas translucent-type colonies had no …
Usefulness of omp1 restriction mapping for avian Chlamydia psittaci isolate differentiation
1995
Abstract Sixty-five avian Chlamydia psittaci isolates collected worldwide, including 27 previously characterized reference strains, were analysed by restriction mapping of the major outer membrane protein gene ( omp1 ) obtained after DMA amplification by PCR. They were compared to 2 ruminant isolates, a feline pneumonitis and a guinea pig inclusion conjunctivitis (GPIC) isolate. According to their omp1 restriction patterns, avian strains were heterogeneous in that they exhibited 6 and 4 distinct patterns using Alu I and Mbo II restriction enzymes, respectively, thus defining 7 groups. However, 84% of the studied strains belonged to groups 1 to 4, which share a specific fragment triplet of 4…
Functional characterization of ORCTL2--an organic cation transporter expressed in the renal proximal tubules.
1998
AbstractChromosome 11p15.5 harbors a gene or genes involved in Beckwith-Wiedemann syndrome that confer(s) susceptibility to Wilms' tumor, rhabdomyosarcoma, and hepatoblastoma. We have previously identified a transcript at 11p15.5 which encodes a putative membrane transport protein, designated organic cation transporter-like 2 (ORCTL2), that shares homology with tetracycline resistance proteins and bacterial multidrug resistance proteins. In this report, we have investigated the transport properties of ORCTL2 and show that this protein can confer resistance to chloroquine and quinidine when overexpressed in bacteria. Immunohistochemistry analyses performed with anti-ORCTL2 polyc.onal antibod…
Hydrophobic mismatch of mobile transmembrane helices: Merging theory and experiments
2012
Abstract Hydrophobic mismatch still represents a puzzle for transmembrane peptides, despite the apparent simplicity of this concept and its demonstrated validity in natural membranes. Using a wealth of available experimental 2 H NMR data, we provide here a comprehensive explanation of the orientation and dynamics of model peptides in lipid bilayers, which shows how they can adapt to membranes of different thickness. The orientational adjustment of transmembrane α-helices can be understood as the result of a competition between the thermodynamically unfavorable lipid repacking associated with peptide tilting and the optimization of peptide/membrane hydrophobic coupling. In the positive misma…
“BEP” RNAs and Proteins Are Situated in the Animal Side of Sea Urchin Unfertilized Egg, Which Can Be Recognized by Female Pronuclear Localization
1996
Microsurgery experiments demonstrate that the animal side of the unfertilized sea urchin Paracentrotus lividus egg coincides with the side of the egg pronucleus location. It is demonstrated by means of in situ hybridization and immunostaining of whole mounts of animal or vegetal halves that the previously identified bep 1 and bep4 RNAs and their proteins are located in the animal part of the unfertilized egg and much less in the vegetal part. The addition of Fabs against BEP1 and BEP4 causes exogastrulation.
Heme oxygenase-1 induction by nitric oxide in RAW 264.7 macrophages is upregulated by a cyclo-oxygenase-2 inhibitor.
2001
Unstimulated RAW 264.7 macrophages express negligible heme oxygenase-1 (HO-1) protein but incubation with the nitric oxide (NO) donor spermine nonoate (SPNO) induced HO-1 and weakly cyclo-oxygenase-2 (COX-2) protein. This effect was potentiated by coincubation with the COX-2 selective inhibitor, SC58125. Cells incubated with SPNO showed a strong increase in HO-1 mRNA levels after 4 h with a significant potentiation in the presence of SC58125, which did not modify HO-1 mRNA stability. The induction of HO-1 by NO and its potentiation by anti-inflammatory agents may play a role in inflammatory and immune responses.
BBE31 from the Lyme disease agent Borrelia burgdorferi, known to play an important role in successful colonization of the mammalian host, shows the a…
2019
Abstract Lyme disease is a tick-borne infection caused by Borrelia burgdorferi sensu lato complex spirochetes. The spirochete is located in the gut of the tick; as the infected tick starts the blood meal, the spirochete must travel through the hemolymph to the salivary glands, where it can spread to and infect the new host organism. In this study, we determined the crystal structures of the key outer surface protein BBE31 from B. burgdorferi and its orthologous protein BSE31 (BSPA14S_RS05060 gene product) from B. spielmanii. BBE31 is known to be important for the transfer of B. burgdorferi from the gut to the hemolymph in the tick after a tick bite. While BBE31 exerts its function by intera…
Homozygous deletions localize novel tumor suppressor genes in B-cell lymphomas
2007
AbstractIntegrative genomic and gene-expression analyses have identified amplified oncogenes in B-cell non-Hodgkin lymphoma (B-NHL), but the capability of such technologies to localize tumor suppressor genes within homozygous deletions remains unexplored. Array-based comparative genomic hybridization (CGH) and gene-expression microarray analysis of 48 cell lines derived from patients with different B-NHLs delineated 20 homozygous deletions at 7 chromosome areas, all of which contained tumor suppressor gene targets. Further investigation revealed that only a fraction of primary biopsies presented inactivation of these genes by point mutation or intragenic deletion, but instead some of them w…