Search results for "cytoplasm"

Double-spanning Plant Viral Movement Protein Integration into the Endoplasmic Reticulum Membrane Is Signal Recognition Particle-dependent, Translocon…

2005

The current model for cell-to-cell movement of plant viruses holds that transport requires virus-encoded movement proteins that intimately associate with endoplasmic reticulum membranes. We have examined the early stages of the integration into endoplasmic reticulum membranes of a double-spanning viral movement protein using photocross-linking. We have discovered that this process is cotranslational and proceeds in a signal recognition particle-dependent manner. In addition, nascent chain photocross-linking to Sec61alpha and translocating chain-associated membrane protein reveal that viral membrane protein insertion takes place via the translocon, as with most eukaryotic membrane proteins, …

Is the nuclear status of an embryo an independent factor to predict its ability to develop to term?

2012

Objective To determine the prognostic impact of the embryo nuclear status at day 2 among other major morphologic parameters (first cleavage at day 1, number of blastomeres and anuclear fragmentation at day 2) on the birth rate. Design Retrospective study. Setting Hospital IVF department. Patient(s) Women undergoing 1,629 day 2 transfers of 2,732 embryos from May 2006 to November 2008. Intervention(s) Four groups according to the embryo nuclear status. Main Outcome Measure(s) Implantation, miscarriage, and birth rates. Result(s) Univariate analysis indicated significantly higher birth rates when all blastomeres were mononucleated (15.0%) compared with embryos with not all blastomeres mononuc…

The histone deacetylase sirtuin 2 is a new player in the regulation of platelet function

2015

SummaryBackground Histone deacetylases (HDACs) play a key role in signaling in many cell types. However, little is known about the participation of HDACs, particularly sirtuins (SIRTs), in platelet reactivity. Objective To investigate the role of HDACs in platelets, we examined the effects of SIRT inhibition on platelet function and protein acetylation in human platelets. Methods We used washed platelets obtained from healthy subjects. Cambinol (SIRT1 and SIRT2 inhibitor), AGK2 (specific SIRT2 inhibitor) and EX527 (specific SIRT1 inhibitor) were used as SIRT inhibitors. Platelets were stimulated with collagen, thrombin, or U46619, and platelet responses were determined according to optical …

The effect of hormone replacement therapy on Ca2+ mobilization and P-selectin (CD62P) expression in platelets examined under flow cytometry.

2004

A series of events, such as increase of cytoplasmic free calcium (Ca 2+ ) and expression of P-selectin (CD62P), an adhesion molecule, on the platelet surface, are significant indicators of platelet activation. We have used flow cytometry to examine Ca 2+ mobilization and CD62P expression in platelets in whole blood obtained in women prior to, and after, different forms of hormone replacement therapy. Thirty-two women completed a protocol consisting of two consecutive 1-month periods under oestradlol (E 2 ), administered orally (2 mg/day) or transdermally (50 μg/day) in random order, followed by a 4-week transdermal sequential regime, in which, during the last 14 days, either progesterone (3…

Involvement of the Pseudomonas aeruginosa MexAB–OprM efflux pump in the secretion of the metallophore pseudopaline

2020

ABSTRACTThe ability for all organisms to acquire metals from their environment is essential for life. To overcome the metal restriction imposed by the host’s nutritional immunity, bacterial pathogens exploits the use of small high metal affinity molecules called metallophores. Metallophores are first synthetized in the cytoplasm, then secreted into the medium where they sequester the metal. The metal-metallophore complex is then imported into the bacterium following binding to dedicated cell surface receptors. Recently, a new family of metallophores has been discovered in pathogenic bacteria called staphylopine in Staphylococcus aureus and pseudopaline in Pseudomonas aeruginosa. Here, we ar…

Binding of Bacillus thuringiensis toxins in resistant and susceptible strains of pink bollworm (Pectinophora gossypiella)

2003

Abstract Evolution of resistance by pests could cut short the success of transgenic plants producing toxins from Bacillus thuringiensis, such as Bt cotton. The most common mechanism of insect resistance to B. thuringiensis is reduced binding of toxins to target sites in the brush border membrane of the larval midgut. We compared toxin binding in resistant and susceptible strains of Pectinophora gossypiella, a major pest of cotton worldwide. Using Cry1Ab and Cry1Ac labeled with 125I and brush border membrane vesicles (BBMV), competition experiments were performed with unlabeled Cry1Aa, Cry1Ab, Cry1Ac, Cry1Ba, Cry1Ca, Cry1Ja, Cry2Aa, and Cry9Ca. In the susceptible strain, Cry1Aa, Cry1Ab, Cry1…

In Vivo and In Vitro Binding of Vip3Aa to Spodoptera frugiperda Midgut and Characterization of Binding Sites by 125 I Radiolabeling

2014

ABSTRACT Bacillus thuringiensis vegetative insecticidal proteins (Vip3A) have been recently introduced in important crops as a strategy to delay the emerging resistance to the existing Cry toxins. The mode of action of Vip3A proteins has been studied in Spodoptera frugiperda with the aim of characterizing their binding to the insect midgut. Immunofluorescence histological localization of Vip3Aa in the midgut of intoxicated larvae showed that Vip3Aa bound to the brush border membrane along the entire apical surface. The presence of fluorescence in the cytoplasm of epithelial cells seems to suggest internalization of Vip3Aa or a fragment of it. Successful radiolabeling and optimization of the…

Human renal tubular epithelial cells as target cells for antibodies to proteinase 3 (c-ANCA)

1997

In Vitro Interactions of C-ANCA (Antibodies to Proteinase 3) with Human Endothelial Cells

1993

Several concepts concerning the pathogenicity of antineutrophil cytoplasmic antibodies (ANCA) exist, but till now only sparse data about ANCA-endothelial interactions are available. In this study we have investigated the expression of proteinase 3 (PR-3) in human umbilical endothelial cells (HEC) using purified anti-PR3 antibodies (C-ANCA) of patients with Wegener’s granulomatosis (WG) and monoclonal antibodies to PR-3 (human and murine) as probes. Performing cytoELISAs, laser scanning microscopy and Western blot we were able to show that treatment of HEC with IL-1-alpha led to an increased PR-3 expression in the cytoplasm and to a transient translocation into the EC-membrane. Representing …

Expression of Putative Fatty Acid Transporter Genes Are Regulated by Peroxisome Proliferator-activated Receptor α and γ Activators in a Tissue- and I…

1998

Regulation of gene expression of three putative long-chain fatty acid transport proteins, fatty acid translocase (FAT), mitochondrial aspartate aminotransferase (mAspAT), and fatty acid transport protein (FATP), by drugs that activate peroxisome proliferator-activated receptor (PPAR) alpha and gamma were studied using normal and obese mice and rat hepatoma cells. FAT mRNA was induced in liver and intestine of normal mice and in hepatoma cells to various extents only by PPARalpha-activating drugs. FATP mRNA was similarly induced in liver, but to a lesser extent in intestine. The induction time course in the liver was slower for FAT and FATP mRNA than that of an mRNA encoding a peroxisomal en…