Search results for "binding"
showing 10 items of 3896 documents
A stage-specific functional role of the leucine zipper transcription factor c-Maf in lung Th2 cell differentiation.
2004
The transcription factor c-Maf controls IL-4 gene expression in CD4(+) T cells, and its expression is up-regulated in human asthmatic airways after allergen challenge. In the present study, we addressed the role of c-Maf in asthma by studying transgenic (Tg) mice overexpressing c-Maf in CD4(+) T cells under the control of the CD2 promoter. As shown, lung CD4(+) T cells of c-maf-Tg mice produced more IL-5 at the early stage (day 2) of culture in the presence of IL-4 than wild-type control cells. Consistently, c-maf-Tg mice spontaneously showed increased IL-5 expression and eosinophils in the bronchial alveolar lavage fluid (BALF) and activated IL-5 signal transduction via Raf-1 and Ras in lu…
Essential role of surface-bound chemoattractant in leukocyte migration
1977
MANY chemotactic factors, usually proteins or peptides, have been isolated and studied, but little is known about the basic mechanism of leukocyte migration. This movement is termed chemotaxis if its direction is determined by substances in the cells' environment1. The chemotactic agent is assumed to convey information to the leukocytes by interaction with receptors. The subsequent sequence of events thus triggered in the cells is unknown but metabolic changes such as activation of an esterase have been reported as occurring as the cells move forward (for review see ref. 2). A role for surface-bound chemoattractant in cell locomotion was suggested by the observation that mouse fibroblasts m…
Cigarette smoke increases BLT2 receptor functions in bronchial epithelial cells: in vitro and ex vivo evidence
2013
Summary Leukotriene B4 (LTB4) is a neutrophil chemotactic molecule with important involvement in the inflammatory responses of chronic obstructive pulmonary disease (COPD). Airway epithelium is emerging as a regulator of innate immune responses to a variety of insults including cigarette smoke, the major risk factor for COPD. In this study we have explored whether cigarette smoke extracts (CSE) or soluble mediators present in distal lung fluid samples (mini-bronchoalveolar lavages) from smokers alter the expression of the LTB4 receptor 2 (BLT2) and peroxisome proliferator-activated receptor-α (PPAR-α) in bronchial epithelial cells. We also evaluated the effects of CSE on the expression of i…
HSP27 controls GATA-1 protein level during erythroid cell differentiation.
2010
AbstractHeat shock protein 27 (HSP27) is a chaperone whose cellular expression increases in response to various stresses and protects the cell either by inhibiting apoptotic cell death or by promoting the ubiquitination and proteasomal degradation of specific proteins. Here, we show that globin transcription factor 1 (GATA-1) is a client protein of HSP27. In 2 models of erythroid differentiation; that is, in the human erythroleukemia cell line, K562 induced to differentiate into erythroid cells on hemin exposure and CD34+ human cells ex vivo driven to erythroid differentiation in liquid culture, depletion of HSP27 provokes an accumulation of GATA-1 and impairs terminal maturation. More spec…
Alkyl and aryl substituted corroles. 3. Reactions of cofacial cobalt biscorroles and porphyrin-corroles with pyridine and carbon monoxide.
2002
The synthesis and characterization of three new cofacial biscorroles and three new linked Co(II) porphyrins and Co(III) corroles with the same face to face orientation are described. The biscorroles are represented as (BCS)Co(2), (BCO)Co(2), (BCX)Co(2) while the porphyrin-corrole dyads are represented as (PCA)Co(2), (PCB)Co(2), (PCO)Co(2) where BC represents the Co(III) cofacial biscorroles and PC represents the porphyrin-corrole complexes which are linked to each other by a dibenzothiophene (S), dibenzofuran (O), or 9,9-dimethylxanthene (X) bridge in the case of the corroles and an anthracene (A), biphenylene (B), or dibenzofuran (O) bridge in the case of the mixed macrocycle derivatives. …
Human Hsp60 with Its Mitochondrial Import Signal Occurs in Solution as Heptamers and Tetradecamers Remarkably Stable over a Wide Range of Concentrati…
2014
It has been established that Hsp60 can accumulate in the cytosol in various pathological conditions, including cancer and chronic inflammatory diseases. Part or all of the cytosolic Hsp60 could be naive, namely, bear the mitochondrial import signal (MIS), but neither the structure nor the in solution oligomeric organization of this cytosolic molecule has still been elucidated. Here we present a detailed study of the structure and self-organization of naive cytosolic Hsp60 in solution. Results were obtained by different biophysical methods (light and X ray scattering, single molecule spectroscopy and hydrodynamics) that all together allowed us to assay a wide range of concentrations of Hsp60…
Guanosine-Mediated Anxiolytic-Like Effect: Interplay with Adenosine A1 and A2A Receptors
2020
Acute or chronic administration of guanosine (GUO) induces anxiolytic-like effects, for which the adenosine (ADO) system involvement has been postulated yet without a direct experimental evidence. Thus, we aimed to investigate whether adenosine receptors (ARs) are involved in the GUO-mediated anxiolytic-like effect, evaluated by three anxiety-related paradigms in rats. First, we confirmed that acute treatment with GUO exerts an anxiolytic-like effect. Subsequently, we investigated the effects of pretreatment with ADO or A1R (CPA, CCPA) or A2AR (CGS21680) agonists 10 min prior to GUO on a GUO-induced anxiolytic-like effect. All the combined treatments blocked the GUO anxiolytic-like effect, …
Photoaffinity Labeling and Photoaffinity Cross-Linking of Phosphofructokinase-1 from Saccharomyces cerevisiae by 8-Azidoadeninenucleotides
2001
Phosphofructokinase-1 from Saccharomyces cerevisiae is composed of four alpha- and four beta-subunits, each of them carrying catalytic and regulatory bindings sites for MgATP. In this paper, various photoaffinity labels, such as 8-azidoadenosine 5'-triphosphate, 8-azido-1,N6-ethenoadenosine 5'-triphosphate, and 8-N3-3'(2')-O-biotinyl-8-azidoadenosine 5'-triphosphate have been used to study their interaction with the enzyme in the dark and during irradiation. All nucleotidetriphosphates function as phosphate donor forming fructose 1,6-bisphosphate from fructose 6-phosphate. However, the kinetic analysis revealed distinctly differences between them. Photolabeling causes a decrease in enzyme a…
Molybdenum Trioxide Nanoparticles with Intrinsic Sulfite Oxidase Activity
2014
Sulfite oxidase is a mitochondria-located molybdenum-containing enzyme catalyzing the oxidation of sulfite to sulfate in the amino acid and lipid metabolism. Therefore, it plays a major role in detoxification processes, where defects in the enzyme cause a severe infant disease leading to early death with no efficient or cost-effective therapy in sight. Here we report that molybdenum trioxide (MoO3) nanoparticles display an intrinsic biomimetic sulfite oxidase activity under physiological conditions, and, functionalized with a customized bifunctional ligand containing dopamine as anchor group and triphenylphosphonium ion as targeting agent, they selectively target the mitochondria while bein…
Light-Induced Protein-Matrix Uncoupling and Protein Relaxation in Dry Samples of Trehalose-Coated MbCO at Room Temperature
2005
In humid samples of trehalose-coated carboxy-myoglobin (MbCO), thermally driven conformational relaxation takes place after photodissociation of the carbon monoxide (CO) molecule at room temperature. In such samples, because of the extreme viscosity of the external matrix, photodissociated CO cannot diffuse out of the protein and explores the whole (proximal and distal side) heme pocket, experiencing averaged protein heme pocket structures, as a result of the presence of Brownian motions. At variance, in very dry samples, a lower portion of the photodissociated CO diffuses from the distal to the proximal heme pocket side probing in nonaveraged structures. We revisit here the flash photolysi…