Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P02794 (ferritin)
 17,525 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mannose-binding sites were detected at the ultrastructural level in nuclei of lizard granulosa cells in situ by means of mannosylated ferritin. When ultrathin sections of material embedded in glycol methacrylate were incubated with mannosylated ferritin, a strong labelling was observed over nucleoli, chromatin and the external leaflet of the nuclear envelope, but no labelling was detected in the perinuclear space except for nuclear pores. This labelling was clearly inhibited when sections were incubated in a solution containing both mannosylated ferritin and a sugar-related neoglycoprotein (mannosylated serum albumin). These ultrastructural data supporting the existence of nuclear lectin-like components in reptilian cells are in agreement with our previous findings about such components in nuclei isolated from mammalian cells. Owing to the unique organization of the granular component of the nucleoli in specialized granulosa cells, we are able to show that some of the mannose-binding sites are associated with ribosomal precursors.
 ...
PMID:In situ ultrastructural localization of sugar-binding sites in lizard granulosa cell nuclei. 293 91

D-mannose, D-galactose, N-acetyl-D-galactosamine, N-acetyl-D-glucosamine and L-fucose which are sugar determinants of receptors were found on the surface of neuroblastoma cells by means of four carbohydrate-specific lectin groups. Labeling of lectins was performed by horseradish peroxidase, ferritin and colloidal gold. Peculiarities of the lectin receptors distribution on the surface of immature neuroblastoma cells were detected.
 ...
PMID:[Localization of lectin receptors on the surface of C1300 neuroblastoma cells]. 375 84

Basal laminae were separated from Schwann cells of mouse sciatic nerves by sonification, and the distributions of lectin-binding sites were demonstrated by electron microscopy using ferritin-conjugated lectins. Only three out of the 11 lectins examined were bound to the basal laminae of Schwann cells: they were Ricinus communis agglutinin-I (RCA-I), Canavalia ensiformis agglutinin (ConA) and Triticum vulgaris agglutinin (wheat germ agglutinin, WGA). It was notable that WGA was bound more densely to the cellular side than to the interstitial side, whereas in the case of RCA-I and ConA there were no differences in the binding density on the two sides of the basal lamina. These results indicate that there are sugar residues such as beta-D-galactose, alpha-D-mannose, alpha-D-glucose and beta(1-4) linked N-acetyl-D-glucosamine in the Schwann cell basal laminae. The first three sugar residues are almost equally densely distributed on the cellular and interstitial sides of the basal laminae, whereas beta(1-4) linked N-acetyl-D-glucosamine is more densely distributed on the cellular than on the interstitial side. This result suggests that the basal lamina has a polarity in chemical composition between the cellular and interstitial sides. These findings are discussed in the context of the preferential attachment of regenerating axons to the cellular side of the Schwann cell basal laminae.
 ...
PMID:The localization of lectin-binding sites on Schwann cell basal lamina. 383 61

Emulphogene-solubilized chicken macrophages were used for the isolation of the mannose receptor by affinity chromatography on mannose-sepharose. From 5 X 10(9) cells 1 microgram protein was obtained, which was separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) into 2 bands with an approximate molecular weight of 130 and 170 kDa. The agglutinating activity was assayed with mannan-coated M. luteus cells. Agglutination was inhibited by D-mannose, L-fucose and D-N-acetylglucosamine. A rabbit antibody against the protein competed with mannan and mannosylated ferritin for the binding sites. The receptor was localized by immunolabelling on ultrathin frozen sections and the relative density of labelling/cell compartment was calculated. The receptor appeared randomly distributed on the surface. Labelling of coated pits was occasional. A higher density of the gold marker was found on surface infoldings (filopods, lamellopods). Subcellular membranous structures contained few labelled regions, with a relative increase from rough endoplasmatic reticulum to Golgi vacuoles. The highest average density was found on membranes of large vesicles near the surface, presumably derived from lamellopods which fuse at their tips to create an internalized vacuole. Fluorescence micrographs showed the complex folding of plasma processes, sometimes forming crater-like apertures. The particular fluorescence intensity of methanol-fixed cells, due to large vesicles, reflects the amount of receptor which is not exposed on the surface. The extent of receptor-rich membrane involved in formation of surface infoldings, craters and large vesicles indicates their role in receptor traffic in the absence of specific ligands.
 ...
PMID:Immunocytochemical localization of the mannose receptor on ultrathin cryosections of chicken macrophages. 389 46

Chrysotile asbestos interacts with mucin-secreting cells of tracheal organ cultures, causing an increase in secretion of mucin into the culture medium. This response occurs in the absence of obvious morphologic damage to tracheal epithelial cells. We speculated that asbestos-induced hypersecretion was regulated by the interaction of fibers with specific carbohydrate residues on the cell surface. To test this hypothesis, lectins, i.e., proteins with a high affinity for mono- and oligosaccharides on the plasma membrane, were added to tissues 30 min before addition of chrysotile. Secretion of mucin into the medium was then determined over a 2-hr period by using incorporation of 3H-glucosamine. Blocking of alpha-D-mannose and alpha-D-glucose residues inhibited chrysotile-induced hypersecretion (p less than 0.05), whereas lectins blocking residues of alpha-D-N-acetylgalactosamine, beta-D-N-acetylglucosamine, alpha-L-fucose and sialic acids were ineffective. Preincubation of cultures with carboxypeptidase A or phospholipase A2, but not with neuraminidase, diminished mucin secretion caused by chrysotile. To determine if the positive surface charge of chrysotile was important in interaction with mucin cells, we examined comparatively the effects of various polycations (cationic ferritin, polylysine, DEAE-dextran) and chrysotile after leaching of fibers to remove Mg2+. Although use of polycations enhanced secretion of mucin, effects were not as striking as those observed with chrysotile. In contrast, leached chrysotile failed to elicit a hypersecretory response. These results suggest the interaction of a positively charged component (presumably Mg2+) of chrysotile with glycolipids and glycoproteins containing terminal residues of alpha-D-mannose or alpha-D-glucose.
 ...
PMID:Studies using lectins to determine mineral interactions with cellular membranes. 631 63

The arrangement of carbohydrate molecules on surfaces of fungal cells may play an important role in nonself recognition of these microorganisms by potential invertebrate hosts. Changes in the ability of various galactose and mannose-specific lectins to bind to surface components on cell walls of the insect pathogen Paecilomyces farinosus were therefore examined during growth and differentiation of the fungus. Fluorescein isothiocyanate conjugates of concanavalin A (Con A, specific for alpha-D-mannose) and peanut agglutinin (PNA, beta-D-galactose) bound inconsistently to blastospores and weakly to mycelia except at apical regions where strong fluorescence was observed. Labeling patterns were similar on cells tested with a galactose-specific lectin purified from Spodoptera exigua (beet armyworm) hemolymph, but Bandeiraea simplicifolia lectin (BS-I alpha-D-galactose) bound only to mycelia. Electron microscopy using ferritin and gold probes showed that the galactomannans are located in a loosely bound coating on the cell wall surface. Variations in lectin binding patterns are apparently due to absence (e.g., by shedding) of the coat or to rearrangement of carbohydrate components in the coat. Staining of Western blots of dithiothreitol (DTT) cell wall extracts further indicated that the BS-I-binding entity is a unique component of the mycelial surface since, as in the fluorescence studies, blastospore preparations were not labeled. Staining of blastospore blots with other galactose-specific probes (e.g., PNA) was comparable to staining of mycelial blots.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Variations in the ability of galactose and mannose-specific lectins to bind to cell wall surfaces during growth of the insect pathogenic fungus Paecilomyces farinosus. 833 Jun 30

Although polymorphonuclear (PMNL) glucose consumption as an index of metabolic response to phagocytosis in the production of free radical species is depressed in hemodialyzed patients, substantial interindividual differences are registered. Studies evaluating to what variables these differences are related are, however, lacking. In the present study, the relation of several factors to PMNL functional capacity in the breakdown of glucose to CO2 by the hexose monophosphate shunt (HMS) is considered in an individual and multifactorial regression analysis. Starting from a database, collected in 126 stabilized hemodialysis patients, PMNL HMS-response to standard quantities of latex and zymosan was correlated to 14 numerical parameters: time since the start of dialysis, hematocrit, serum creatinine, phosphorus, ferritin, albumin, parathormone, albumin before and after administration of desferrioxamine, residual creatinine clearance, PCR, TACurea, Kt/V and age. In addition, the non-numeric parameters of sex, biocompatibility of dialyzers, and primary diagnosis were also considered. A significant correlation was found for time on dialysis (P < 0.001), hematocrit (P < 0.001), ferritin (P < 0.05), PTH (P < 0.001) and aluminum (P < 0.05). The highest correlation coefficients were found for time on dialysis (latex: N = 126, r = 0.50, P < 0.001; zymosan: N = 126, r = 0.58, P < 0.001). Multivariate correlation analysis of one clinical parameter together with time on dialysis to PMNL response showed that the correlation was strongly weakened or disappeared for ferritin, aluminum and PTH, but not for hematocrit. Our data indicate that time since the start of dialysis is an important, but not unique factor, influencing polymorphonuclear functional capacity in a hemodialysis population.
 ...
PMID:Contributing factors to the inhibition of phagocytosis in hemodialyzed patients. 835 62

Vibrio cholerae O1 strain TSI-4 (El Tor, Ogawa) can shift to a rugose colony morphology from its normal translucent colony morphology in response to nutrient starvation. We have investigated differences between the rugose and translucent forms of V. cholerae O1 strain TSI-4. Electron microscopic examination of the rugose form of TSI-4 (TSI-4/R) revealed thick, electron-dense exopolysaccharide materials surrounding polycationic ferritin-stained cells, while the ferritin-stained material was absent around the translucent form of TSI-4 (TSI-4/T). The exopolysaccharide produced by V. cholerae TSI-4/R was found to have a composition of N-acetyl-D-glucosamine, D-mannose, 6-deoxy-D-galactose, and D-galactose (7.4:10.2:2.4:3.0). The expression of an amorphous exopolysaccharide promotes biofilm development under static culture conditions. Biofilm formation by the rugose strain was determined by scanning electron microscopy, and most of the surface of the film was colonized by actively dividing rod cells. The corresponding rugose and translucent strains were compared for stress resistance. By having exopolysaccharide materials, the rugose strains acquired resistance to osmotic and oxidative stress. Our data indicated that an exopolysaccharide material on the surface of the rugose strain promoted biofilm formation and resistance to the effects of two stressing agents.
 ...
PMID:Vibrio cholerae O1 strain TSI-4 produces the exopolysaccharide materials that determine colony morphology, stress resistance, and biofilm formation. 975 80

Nitrogen monoxide (NO) is a cytotoxic effector molecule produced by macrophages that results in Fe mobilization from tumour target cells which inhibits DNA synthesis and mitochondrial respiration. It is well known that NO has a high affinity for Fe, and we showed that NO-mediated Fe mobilization is markedly potentiated by glutathione (GSH) generated by the hexose monophosphate shunt [Watts, R.N. & Richardson, D.R. (2001) J. Biol. Chem. 276, 4724-4732]. We hypothesized that GSH completes the coordination shell of an NO[bond]Fe complex that is released from the cell. In this report we have extended our studies to further characterize the mechanism of NO-mediated Fe mobilization. Native PAGE 59Fe-autoradiography shows that NO decreased ferritin-59Fe levels in cells prelabelled with [59Fe]transferrin. In prelabelled cells, ferritin-59Fe levels increased 3.5-fold when cells were reincubated with control media between 30 and 240 min. In contrast, when cells were reincubated with NO, ferritin-59Fe levels decreased 10-fold compared with control cells after a 240-min reincubation. However, NO could not remove Fe from ferritin in cell lysates. Our data suggest that NO intercepts 59Fe on route to ferritin, and indirectly facilitates removal of 59Fe from the protein. Studies using the GSH-depleting agent, L-buthionine-(S,R)-sulphoximine, indicated that the reduction in ferritin-59Fe levels via NO was GSH-dependent. Competition experiments with NO and permeable chelators demonstrated that both bind a similar Fe pool. We suggest that NO requires cellular metabolism in order to effect Fe mobilization and this does not occur via passive diffusion down a concentration gradient. Based on our results, we propose a model of glucose-dependent NO-mediated Fe mobilization.
 ...
PMID:The mechanism of nitrogen monoxide (NO)-mediated iron mobilization from cells. NO intercepts iron before incorporation into ferritin and indirectly mobilizes iron from ferritin in a glutathione-dependent manner. 1213 76

Carbohydrate-lectin interactions are important in many biological events. Endogenous cell-surface lectins are attractive markers for the recognition and targeting. Human ferritin protein cage nanoparticles (HFPCNs) are prepared as delivery nanoplatforms and two different types of monosaccharide derivatives; maleimido group terminated-mannopyranoside and galactopyranoside. Uniform and polyvalent displays of mannoses or galactoses on the surface of HFPCNs are achieved by using site-specific thiol-maleimide Michael-type addition. Mannose- or galactose-displaying HFPCNs recognize and tightly bind to DC-SIGN or ASGP-R lectins on the surface of the mammalian cells, DCEK or HepG2 cells.
...
PMID:Polyvalent display of monosaccharides on ferritin protein cage nanoparticles for the recognition and binding of cell-surface lectins. 2451 82


<< Previous 1 2