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Query: UNIPROT:Q9UIJ5 (
Rec
)
58,342
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Freeze-fracture combined with quantitative electron microscopy of the intact human erythrocyte (RBC) and ghost revealed significant differences in their intramembranous particle coefficients. External (E) fracture-faces of unfixed ghost membranes were found to contain 40% fewer particles than those of intact unfixed RBC. The particle distribution of the intact RBC membrane depended on the use of glutaraldehyde fixation and glycerol cryoprotection. Whereas glutaraldehyde- and glycerol-treated cells disclosed 70% fewer E-face particles than did intact unfixed cells, poly-L-lysine-treated, intact, unfixed RBC showed no such differences. Treatment with a combination of poly-L-lysine and glutaraldehyde, however, increased the amount of E-face particles while reducing those of the protoplasmic (P) face. The poly-L-lysine effect varied with its concentration and was unaffected by previous application of neuraminidase. Nor did the
lectin
phytohemagglutinin induce particle rearrangement in intact cells. Our data demonstrate that the processes of glutaraldehyde fixation and glycerol cryoprotection modify the RBC membrane by decreasing the number of E-face particles present. In addition, the combination of poly-L-lysine and glutaraldehyde alters the affinity of some particles for one half of the membrane, suggesting that in freeze-fractured RBC, chemical bonds formed at the extracellular surface of the membrane can influence particle partitioning.
Anat
Rec
1977 Dec
PMID:Intramembranous particle distribution in human erythrocytes: effects of lysis, glutaraldehyde, and poly-L-lysine. 41 58
Concanavalin A (Con A), a
lectin
binding to mannosyl and glucosyl residues of glycoproteins and glycolipids, was used to study the appearance of carbohydrate-rich cell surface material on the olfactory placode and nasal processes which contribute to formidine was also used in an attempt to correlate changes in labeling index with formation of the olfactory placode and nasal processes. The cell surface of the early frontonasal epithelium binds Con A very little, if at all, but Con A binding was observed when the olfactory placode could be identified as a plate of cuboidal cells that exhibited a reduced labeling index. During the period of formation of the nasal processes, Con A binding was observed on the facial epithelium including the presumptive contact region. There was also a decline in the labeling index throughout primary palate formation. This study provides three criteria by which the olfactory placode can be identified: a morphological change of placode cells to a cuboidal shape, a synthesis or rearrangement of surface coat material that binds Con A, and a reduced labeling index.
Anat
Rec
1977 May
PMID:Concanavalin A binding to the epithelial surface of the developing mouse olfactory placode. 86 29
The isolectin B4 of Griffonia simplicifolia (GSA I-B4) binds to cell membrane glycoconjugates bearing terminal alpha-D-galactose, which macrophages possess. We have investigated the merits of its use as a marker for cells of this lineage when examining the early origin of macrophage populations in rat embryos, the stages and time scale of transformation from precursor forms to active, matured cells, and the response of precursors and macrophages to colony-stimulating blood factors, the last two studies conducted in organ cultures of prenatal lungs. In the present instance, GSA I-B4 was used either coupled with fluorescein (FITC) for light microscopy of living and fixed cells, or with peroxidase for light or electron microscopy. Control incubations of lung culture-derived macrophages proved that staining resulted from specific binding to galactosyl units on the cell membrane, since it was competitively inhibited by alpha-D-galactose. The
lectin
binds to few cells in 14-day prenatal lung explants but to a great many macrophages that subsequently develop in the cultures, indicating that it can be relied on for quantitative studies on population growth; however, it is important to provide reagents with good access to the cells. Apart from macrophages and their precursors, virtually no cells in prenatal lung cultures bind this
lectin
. Granulocytes of adult blood are GSA positive, but they are not yet present in 14-day prenatal explants and do not develop subsequent to culturing; hence they are not a source of confusion for experimental studies using this system. Precursors of granulocytes begin to appear in rat embryos around day 13 and have GSA-positive cell membranes, but like definitive granulocytes they also have conspicuous peroxidase-positive lysosomal granules which serve to distinguish them from early macrophages, particularly when cells are studied at an ultrastructural level. With these objections cleared away, GSA I-B4 emerges as a valuable means to mark cells of the macrophage line, mature or immature.
Anat
Rec
1992 Apr
PMID:Macrophage development: I. Rationale for using Griffonia simplicifolia isolectin B4 as a marker for the line. 137 95
Macro- and microdissection methods together with conventional histology and
lectin
immunohistochemistry have been used to identify the course of the vomeronasal nerves and their site of termination (accessory olfactory bulb; AOB) in the dog. The AOB in this species is small and variable in size, situated on the medial surface of the main olfactory bulb, and has an anatomical structure unlike that described for other mammals. The vomeronasal nerves and their terminal glomeruli in the AOB are easily identifiable by selective immunohistochemical staining using Ulex europeus agglutinin I.
Anat
Rec
1992 Jun
PMID:Anatomical and immunohistological demonstration of the primary neural connections of the vomeronasal organ in the dog. 160 94
To ascertain the histochemical characteristics of surface carbohydrates on avian primordial germ cells (PGC), we examined the distribution of binding sites for several biotinylated lectins in chick and quail embryos. Some binding sites were detected almost selectively with PGC but not with other embryonic sites. Of these,
lectin
from Sojanum tuberosum (STA) reacted with PGC in both avian species, whereas
lectin
from Wistaria floribunda (WFA) and Griffonia simplicifolia II (GS-II) reacted in the quail and the chick, respectively. The binding site for STA was found at the cell surface and cytoplasm of the PGC from their initial appearance in the germinal crescent through migration to sexually indifferent gonads, whereas the WFA reaction was seen at stages before and during migration. These reactivities showed most intensely on the surface of PGC at the peak of their migration. In contrast, GS-II binding site was restricted to the cytoplasm, and its distribution was similar to that of the periodic acid-Schiff (PAS)-positive glycogen granules in chick PGC. These results suggest that some selective binding sites on the PGC surface play a significant role in their migration and show that lectins STA, WFA, and GS-II can be used as probes for identification of the avian PGC.
Anat
Rec
1992 Aug
PMID:Selective lectin-binding sites of primordial germ cells in chick and quail embryos. 162 21
Two glycoforms of a soluble mutant of recombinant human thrombomodulin (
rec
.TM) were used to identify critical N- and O-linked glycans of the endothelial cell thrombin receptor. While N-linked glycans were not found to be involved in any function of
rec
.TM, an acidic chondroitin sulphate-like glycosaminoglycan (CSGAG) was found to be critical for all the direct anticoagulant functions of
rec
.TM, including inhibition of thrombin-mediated platelet aggregation. A glycoform of
rec
.TM lacking CSGAG had very poor anticoagulant activity. Furthermore, the glycoform of
rec
.TM possessing CSGAG showed strong inhibition by and had high affinity for poly-cationic basic proteins, whereas the CSGAG-deficient
rec
.TM did not. Monoclonal antibody binding as well as
lectin
mapping of
rec
.TM with agglutinins identified sialic acid containing O-linked glycans in both glycoforms additional to the CSGAG in high molecular weight
rec
.TM These findings define important molecular interactions modulating the anticoagulant function of TM, which appear to be critically regulated by CSGAG, and also showed that the overall post-translational glycosylation pattern of the two glycoforms was very similar except for the presence of CSGAG. The possibility exists that differently expressed glycoforms of TM may be crucial for the expression of endothelial cell-related anticoagulant potential in different vascular beds.
...
PMID:Relationship between post-translational glycosylation and anticoagulant function of secretable recombinant mutants of human thrombomodulin. 165 91
Changes in the expression of glycoconjugates in cells of the inner root sheath (IRS) and outer root sheath (ORS) of human anagen hair follicles were investigated by
lectin
histochemistry. Concanavalin A (Con A) and Ricinus communis (RCA-I) stained hair follicle cells regardless of their differentiation stages. In IRS, Ulex europeaus-I (UEA-I) bound to the surface of the cells as soon as they were morphologically defined, and Glycine max (SBA) stained as their differentiation progressed. Innermost (IM) cells of ORS layers were reactive with UEA-I at the stage where Henle's cells were keratinized, while the reactivity of UEA-I was lost at the site of the completion of IRS keratinization where SBA reaction was detected. Staining of both UEA-I and SBA was prominent in other ORS cells at the levels where SBA binding in IM cells became strong. The staining intensity increased up to the position of the follicular isthmus. In addition, a sugar residue recognized by Dolichos biflorus (DBA) was detected in differentiated cells of ORS. In contrast, the DBA reaction was not found at all in cells of IRS, infundibulum, and epidermis. These findings identified a complexity of carbohydrate metabolism in the cells of different layers at various stages of keratinization. IM cells differentiate independently from other ORS cells but seem responsive to the degree of IRS keratinization. All ORS cells possess a unique sugar moiety not found in other keratinocytes either in the hair or epidermis.
Anat
Rec
1990 Sep
PMID:Glycoconjugate expression of cells of human anagen hair follicles during keratinization. 170 Jun 46
Lectin binding was studied in the developing airways of Syrian golden hamsters on gestational days 11-16 (day 16 is the day of birth). The trachea and lungs were fixed in 4% formaldehyde-1% glutaraldehyde, 6% mercuric chloride-1% sodium acetate-0.1% glutaraldehyde, and 95% ethanol; embedded in paraffin; and stained with eight
lectin
-horseradish peroxidase conjugates: Triticum vulgare (WGA), Dolichos biflorus (DBA), Helix pomatia (HPA), Maclura pomifera (MPA), Griffonia simplicifolia I-B4 (GSA I-B4), Arachis hypogaea (PNA), Ulex europeus I (UEA I), and Limulus polyphemus (LPA). Each
lectin
yielded a characteristic staining pattern, which modulated throughout development. In general, changes in staining characteristics of the tracheal epithelium preceded similar changes in the lobar bronchus, bronchiole, and alveolus. In the case of UEA I, MPA, WGA, and HPA, staining increased with time uniformly over the luminal surface of all epithelial cells. However, in the case of PNA, GSA I-B4, and LPA, after the differentiation of ciliated and secretory cells, the apical surfaces of the ciliated cells stained more intensely than the apical surfaces of the secretory cells. Neuraminidase pretreatment enhanced PNA and GSA I-B4 staining in both cell types. In the case of PNA, these light microscopic observations were confirmed by ultrastructural study. Unlike the other lectins, the pattern of staining with DBA was unusual. Staining was moderate at first, then decreased (days 13 and 14), then increased at all airway levels. This study shows that different glycoconjugates modulate in airway epithelial cells throughout fetal development.
Anat
Rec
1990 Oct
PMID:Changes in glycoconjugates revealed by lectin staining in the developing airways of Syrian golden hamsters. 170 Jun 50
Differentiation in the mouse embryo begins at the 8-cell stage when the blastomeres spread against each other in a process called compaction. The spreading behavior of blastomeres on
lectin
-coated coverslips mimics that of blastomeres in the embryo, and we have utilized this model system to obtain an en face view of the membrane skeleton in the spreading blastomeres. Embryos were cultured on the coverslips for periods ranging from 20 sec to 6 hr, and the cells were disrupted to expose the cytoplasmic face of the adherent membranes and their associated filaments. The "membrane lawn" preparations were fixed, critical point dried, rotary shadowed, and the replicas examined by transmission electron microscopy. Using this technique we found that the plasmalemma of rounded blastomeres is associated with a lacy 3-dimensional filamentous meshwork that is transformed into a thin mat of densely woven filaments when the cells flatten. The overall organization of the membrane skeleton is similar in flattening 2- and 8-cell embryos, but there are significant differences in the time required for spreading to take place, in the means whereby the membrane skeletons are reorganized, and in the extent of maximal flattening. The significance of these observations for the compaction process is discussed.
Anat
Rec
1991 Oct
PMID:Organization of the membrane skeleton in spreading mouse blastomeres. I. Morphological analysis. 174 23
A selection of lectins was used to investigate developmentally regulated changes in the distribution of cell surface oligosaccharides during the gastrulation and neurulation stages of early chick embryo development. Lectins from three specificity classes were used: glucose/mannose specificity (concanavalin A [Con A], Lens culinaris agglutinin [LCA], Pisum sativum agglutinin [PSA]); N-acetylglucosamine specificity (Lycopersicon esculentum agglutinin [LEA], wheat germ agglutinin [WGA], succinylated WGA [sWGA]); N-acetylgalactosamine/galactose specificity (Dolichos biflorus agglutinin [DBA], soybean agglutinin [SBA], Sophora japonica agglutinin [SJA], Bandeiraea (Griffonia) simplicifolia
lectin
I [BSL I], peanut agglutinin [PNA], Artocarpus integrifolia
lectin
[Jacalin], Ricinus communis agglutinin-1 [RCA-1], Erythrina cristagalli
lectin
[ECL]). At gastrulation stages, patterns of
lectin
binding could be distinguished in the epiblast, mesoderm, and endoderm cell layers. The primitive streak failed to bind any of the lectins, but LEA and WGA bound to the epiblast in regions lateral to the streak, indicating the loss of some glucosamine residues medially in preparation for the ingression movements of gastrulation. Several lectins showed marked binding to the mesoderm cells after their passage through the primitive streak; these were LCA, PSA, WGA, sWGA, BSL, and most particularly PNA. Therefore, the epithelial-mesenchymal transformation from epiblast to mesoderm at the primitive streak is accompanied by cell surface oligosaccharide changes in the epiblast and mesoderm that involve all classes of lectins including the PNA-binding sequence Gal beta 1-3GalNAc. Ultrastructurally, PNA was shown to bind extracellularly to matrix fibrils. Jacalin, having the same sugar specificity as PNA, but binding to serine/threonine linked chains rather than asparagine linked chains showed no binding to the mesoderm.(ABSTRACT TRUNCATED AT 250 WORDS)
Anat
Rec
1991 Oct
PMID:Changes in glycoconjugate expression during early chick embryo development: a lectin-binding study. 174 24
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