Characterization of specific binding sites for vasoactive intestinal peptide in rat intestinal epithelial cell membranes

1980 ◽  
Vol 627 (2) ◽  
pp. 215-224 ◽  
Author(s):  
Brigitte Amiranoff ◽  
Marc Laburthe ◽  
Gabriel Rosselin
Keyword(s):  
Epithelial Cell ◽  
Vasoactive Intestinal Peptide ◽  
Binding Sites ◽  
Intestinal Epithelial Cell ◽  
Cell Membranes ◽  
Specific Binding ◽  
Intestinal Epithelial ◽  
Specific Binding Sites

scholarly journals Characterization of glycopeptides labelled from d-[2-3H]mannose and l-[6-3H]fucose in intestinal epithelial cell membranes during differentiation

1980 ◽  
Vol 192 (1) ◽  
pp. 145-153 ◽  
Author(s):  
A Herscovics ◽  
B Bugge ◽  
A Quaroni ◽  
K Kirsch
Keyword(s):  
Epithelial Cell ◽  
Intestinal Epithelial Cell ◽  
Time Course ◽  
Cell Membranes ◽  
Alkali Treatment ◽  
Gel Filtration ◽  
Intestinal Epithelial ◽  
Membrane Glycoproteins ◽  
High Mannose ◽  
Fraction I

The labelled glycopeptides obtained by Pronase digestion of rat intestinal epithelial cell membranes were examined by gel filtration after injection of D-[2-3H]mannose and L-[6-3H]fucose. Three labelled fraction were eluted in the following order from Bio-Gel P-6, Fraction I, which was excluded from the gel, was labelled mostly with [3H]fucose and slightly with [3H]mannose. Fraction II contained “complex” asparagine-linked oligosaccharides since it was labelled with [3H]mannose and [3H]fucose, was stable to mild alkali treatment, and resistant to endo-beta-N-acetyl-glucosaminidase H. Fraction III contained “high-mannose” asparagine-linked oligosaccharides, which were labelled with [3H]mannose, but not with [3H]fucose; these were sensitive to endo-beta-N-acetylglucosaminidase H, and were adsorbed on concanavalin A-Sepharose and subsequently eluted with methyl alpha-D-mannopyranoside. The time course of incorporation of [3H]mannose into these glycopeptides in microsomal fractions showed that high-mannose oligosaccharides were precursors of complex oligosaccharides. The rate of this processing was faster in rapidly dividing crypt cells than in differentiated villus cells. The ratio of radioactively labelled complex oligosaccharides to high-mannose oligosaccharides, 3h after [3H]mannose injection, was greater in crypt than in villus-cell lateral membranes. Luminal membranes of both crypt and villus cells were greatly enriched in labelled complex oligosaccharides compared with the labelling in lateral-basal membranes. These studies show that intestinal epithelial cells are polarized with respect to the structure of the asparagine-linked oligosaccharides on their membrane glycoproteins. During differentiation of these cells quantitative differences in labelled membrane glycopeptides, But no major qualitative change, were observed.

scholarly journals Tropomyosin distinguishes between the two actin-binding sites of villin and affects actin-binding properties of other brush border proteins.

1987 ◽  
Vol 104 (1) ◽  
pp. 29-40 ◽  
Author(s):  
D R Burgess ◽  
K O Broschat ◽  
J M Hayden
Keyword(s):  
Epithelial Cell ◽  
Protein Interactions ◽  
Brush Border ◽  
Binding Sites ◽  
Intestinal Epithelial Cell ◽  
Actin Binding ◽  
Intestinal Epithelial ◽  
Binding Properties ◽  
Order Of Magnitude ◽  
Protein Components

The intestinal epithelial cell brush border exhibits distinct localizations of the actin-binding protein components of its cytoskeleton. The protein interactions that dictate this subcellular organization are as yet unknown. We report here that tropomyosin, which is found in the rootlet but not in the microvillus core, can bind to and saturate the actin of isolated cores, and can cause the dissociation of up to 30% of the villin and fimbrin from the cores but does not affect actin binding by 110-kD calmodulin. Low speed sedimentation assays and ultrastructural analysis show that the tropomyosin-containing cores remain bundled, and that 110-kD calmodulin remains attached to the core filaments. The effects of tropomyosin on the binding and bundling activities of villin were subsequently determined by sedimentation assays. Villin binds to F-actin with an apparent Ka of 7 X 10(5) M-1 at approximate physiological ionic strength, which is an order of magnitude lower than that of intestinal epithelial cell tropomyosin. Binding of villin to F-actin presaturated with tropomyosin is inhibited relative to that to pure F-actin, although full saturation can be obtained by increasing the villin concentration. Villin also inhibits the binding of tropomyosin to F-actin, although not to the same extent. However, tropomyosin strongly inhibits bundling of F-actin by villin, and bundling is not recovered even at a saturating villin concentration. Since villin has two actin-binding sites, both of which are required for bundling, the fact that tropomyosin inhibits bundling of F-actin under conditions where actin is fully saturated with villin strongly suggests that tropomyosin's and one of villin's F-actin-binding sites overlap. These results indicate that villin and tropomyosin could compete for actin filaments in the intestinal epithelial cell, and that tropomyosin may play a major role in the regulation of microfilament structure in these and other cells.

Characterization of a porcine intestinal epithelial cell line for in vitro studies of microbial pathogenesis in swine

2005 ◽  
Vol 125 (3) ◽  
pp. 293-305 ◽  
Author(s):  
Peter Schierack ◽  
Marcel Nordhoff ◽  
Marion Pollmann ◽  
Karl Dietrich Weyrauch ◽  
Salah Amasheh ◽  
...  
Keyword(s):  
Epithelial Cell ◽  
Cell Line ◽  
Intestinal Epithelial Cell ◽  
In Vitro Studies ◽  
Epithelial Cell Line ◽  
Intestinal Epithelial ◽  
Microbial Pathogenesis ◽  
Porcine Intestinal Epithelial Cell

Characterization of specific binding sites for PAF in the iris and ciliary body of rabbit

1989 ◽  
Vol 160 (1) ◽  
pp. 250-256 ◽  
Author(s):  
M.T. Domingo ◽  
P.E. Chabrier ◽  
J.L. Van Delft ◽  
N.L. Verbeij ◽  
N.J. Van Haeringen ◽  
...  
Keyword(s):  
Binding Sites ◽  
Ciliary Body ◽  
Specific Binding ◽  
Specific Binding Sites
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